diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index e3a2518..63be536 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -33,6 +33,15 @@
 	bool
 	default y if SYSFS
 
+config PWM_DEBUG
+	bool "PWM lowlevel drivers additional checks and debug messages"
+	depends on DEBUG_KERNEL
+	help
+	  This option enables some additional checks to help lowlevel driver
+	  authors to get their callbacks implemented correctly.
+	  It is expected to introduce some runtime overhead and diagnostic
+	  output to the kernel log, so only enable while working on a driver.
+
 config PWM_AB8500
 	tristate "AB8500 PWM support"
 	depends on AB8500_CORE && ARCH_U8500
@@ -44,7 +53,8 @@
 
 config PWM_ATMEL
 	tristate "Atmel PWM support"
-	depends on ARCH_AT91 && OF
+	depends on OF
+	depends on ARCH_AT91 || COMPILE_TEST
 	help
 	  Generic PWM framework driver for Atmel SoC.
 
@@ -100,7 +110,7 @@
 
 config PWM_BCM2835
 	tristate "BCM2835 PWM support"
-	depends on ARCH_BCM2835
+	depends on ARCH_BCM2835 || ARCH_BRCMSTB || COMPILE_TEST
 	help
 	  PWM framework driver for BCM2835 controller (Raspberry Pi)
 
@@ -109,7 +119,7 @@
 
 config PWM_BERLIN
 	tristate "Marvell Berlin PWM support"
-	depends on ARCH_BERLIN
+	depends on ARCH_BERLIN || COMPILE_TEST
 	help
 	  PWM framework driver for Marvell Berlin SoCs.
 
@@ -118,7 +128,7 @@
 
 config PWM_BRCMSTB
 	tristate "Broadcom STB PWM support"
-	depends on ARCH_BRCMSTB || BMIPS_GENERIC
+	depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
 	help
 	  Generic PWM framework driver for the Broadcom Set-top-Box
 	  SoCs (BCM7xxx).
@@ -152,7 +162,7 @@
 
 config PWM_EP93XX
 	tristate "Cirrus Logic EP93xx PWM support"
-	depends on ARCH_EP93XX
+	depends on ARCH_EP93XX || COMPILE_TEST
 	help
 	  Generic PWM framework driver for Cirrus Logic EP93xx.
 
@@ -195,7 +205,7 @@
 
 config PWM_IMX1
 	tristate "i.MX1 PWM support"
-	depends on ARCH_MXC
+	depends on ARCH_MXC || COMPILE_TEST
 	help
 	  Generic PWM framework driver for i.MX1 and i.MX21
 
@@ -204,7 +214,7 @@
 
 config PWM_IMX27
 	tristate "i.MX27 PWM support"
-	depends on ARCH_MXC
+	depends on ARCH_MXC || COMPILE_TEST
 	help
 	  Generic PWM framework driver for i.MX27 and later i.MX SoCs.
 
@@ -222,9 +232,21 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-imx-tpm.
 
+config PWM_IQS620A
+	tristate "Azoteq IQS620A PWM support"
+	depends on MFD_IQS62X || COMPILE_TEST
+	help
+	  Generic PWM framework driver for the Azoteq IQS620A multi-function
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called pwm-iqs620a.
+
 config PWM_JZ4740
 	tristate "Ingenic JZ47xx PWM support"
-	depends on MACH_INGENIC
+	depends on MIPS
+	depends on COMMON_CLK
+	select MFD_SYSCON
 	help
 	  Generic PWM framework driver for Ingenic JZ47xx based
 	  machines.
@@ -244,7 +266,7 @@
 
 config PWM_LPC18XX_SCT
 	tristate "LPC18xx/43xx PWM/SCT support"
-	depends on ARCH_LPC18XX
+	depends on ARCH_LPC18XX || COMPILE_TEST
 	help
 	  Generic PWM framework driver for NXP LPC18xx PWM/SCT which
 	  supports 16 channels.
@@ -256,7 +278,7 @@
 
 config PWM_LPC32XX
 	tristate "LPC32XX PWM support"
-	depends on ARCH_LPC32XX
+	depends on ARCH_LPC32XX || COMPILE_TEST
 	help
 	  Generic PWM framework driver for LPC32XX. The LPC32XX SOC has two
 	  PWM controllers.
@@ -289,7 +311,8 @@
 
 config PWM_MESON
 	tristate "Amlogic Meson PWM driver"
-	depends on ARCH_MESON
+	depends on ARCH_MESON || COMPILE_TEST
+	depends on COMMON_CLK
 	help
 	  The platform driver for Amlogic Meson PWM controller.
 
@@ -318,7 +341,8 @@
 
 config PWM_MXS
 	tristate "Freescale MXS PWM support"
-	depends on ARCH_MXS && OF
+	depends on OF
+	depends on ARCH_MXS || COMPILE_TEST
 	select STMP_DEVICE
 	help
 	  Generic PWM framework driver for Freescale MXS.
@@ -328,7 +352,8 @@
 
 config PWM_OMAP_DMTIMER
 	tristate "OMAP Dual-Mode Timer PWM support"
-	depends on OF && ARCH_OMAP && OMAP_DM_TIMER
+	depends on OF
+	depends on OMAP_DM_TIMER || COMPILE_TEST
 	help
 	  Generic PWM framework driver for OMAP Dual-Mode Timer PWM output
 
@@ -345,18 +370,9 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-pca9685.
 
-config PWM_PUV3
-	tristate "PKUnity NetBook-0916 PWM support"
-	depends on ARCH_PUV3
-	help
-	  Generic PWM framework driver for PKUnity NetBook-0916.
-
-	  To compile this driver as a module, choose M here: the module
-	  will be called pwm-puv3.
-
 config PWM_PXA
 	tristate "PXA PWM support"
-	depends on ARCH_PXA
+	depends on ARCH_PXA || COMPILE_TEST
 	help
 	  Generic PWM framework driver for PXA.
 
@@ -387,14 +403,14 @@
 
 config PWM_ROCKCHIP
 	tristate "Rockchip PWM support"
-	depends on ARCH_ROCKCHIP
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
 	help
 	  Generic PWM framework driver for the PWM controller found on
 	  Rockchip SoCs.
 
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
-	depends on PLAT_SAMSUNG || ARCH_EXYNOS
+	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
 	help
 	  Generic PWM framework driver for Samsung.
 
@@ -412,9 +428,19 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sifive.
 
+config PWM_SL28CPLD
+	tristate "Kontron sl28cpld PWM support"
+	depends on MFD_SL28CPLD || COMPILE_TEST
+	help
+	  Generic PWM framework driver for board management controller
+	  found on the Kontron sl28 CPLD.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-sl28cpld.
+
 config PWM_SPEAR
 	tristate "STMicroelectronics SPEAr PWM support"
-	depends on PLAT_SPEAR
+	depends on PLAT_SPEAR || COMPILE_TEST
 	depends on OF
 	help
 	  Generic PWM framework driver for the PWM controller on ST
@@ -436,7 +462,7 @@
 
 config PWM_STI
 	tristate "STiH4xx PWM support"
-	depends on ARCH_STI
+	depends on ARCH_STI || COMPILE_TEST
 	depends on OF
 	help
 	  Generic PWM framework driver for STiH4xx SoCs.
@@ -446,7 +472,7 @@
 
 config PWM_STM32
 	tristate "STMicroelectronics STM32 PWM"
-	depends on MFD_STM32_TIMERS
+	depends on MFD_STM32_TIMERS || COMPILE_TEST
 	help
 	  Generic PWM framework driver for STM32 SoCs.
 
@@ -482,7 +508,7 @@
 
 config PWM_TEGRA
 	tristate "NVIDIA Tegra PWM support"
-	depends on ARCH_TEGRA
+	depends on ARCH_TEGRA || COMPILE_TEST
 	help
 	  Generic PWM framework driver for the PWFM controller found on NVIDIA
 	  Tegra SoCs.
@@ -490,33 +516,24 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-tegra.
 
-config  PWM_TIECAP
+config PWM_TIECAP
 	tristate "ECAP PWM support"
-	depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_KEYSTONE || ARCH_K3
+	depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_KEYSTONE || ARCH_K3 || COMPILE_TEST
 	help
 	  PWM driver support for the ECAP APWM controller found on TI SOCs
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-tiecap.
 
-config  PWM_TIEHRPWM
+config PWM_TIEHRPWM
 	tristate "EHRPWM PWM support"
-	depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_K3
+	depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_K3 || COMPILE_TEST
 	help
 	  PWM driver support for the EHRPWM controller found on TI SOCs
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-tiehrpwm.
 
-config  PWM_TIPWMSS
-	bool
-	default y if (ARCH_OMAP2PLUS) && (PWM_TIECAP || PWM_TIEHRPWM)
-	help
-	  PWM Subsystem driver support for AM33xx SOC.
-
-	  PWM submodules require PWM config space access from submodule
-	  drivers and require common parent driver support.
-
 config PWM_TWL
 	tristate "TWL4030/6030 PWM support"
 	depends on TWL4030_CORE
@@ -537,7 +554,7 @@
 
 config PWM_VT8500
 	tristate "vt8500 PWM support"
-	depends on ARCH_VT8500
+	depends on ARCH_VT8500 || COMPILE_TEST
 	help
 	  Generic PWM framework driver for vt8500.
 
@@ -546,7 +563,7 @@
 
 config PWM_ZX
 	tristate "ZTE ZX PWM support"
-	depends on ARCH_ZX
+	depends on ARCH_ZX || COMPILE_TEST
 	help
 	  Generic PWM framework driver for ZTE ZX family SoCs.
 
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 26326ad..cbdcd55 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -20,6 +20,7 @@
 obj-$(CONFIG_PWM_IMX1)		+= pwm-imx1.o
 obj-$(CONFIG_PWM_IMX27)		+= pwm-imx27.o
 obj-$(CONFIG_PWM_IMX_TPM)	+= pwm-imx-tpm.o
+obj-$(CONFIG_PWM_IQS620A)	+= pwm-iqs620a.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
 obj-$(CONFIG_PWM_LP3943)	+= pwm-lp3943.o
 obj-$(CONFIG_PWM_LPC18XX_SCT)	+= pwm-lpc18xx-sct.o
@@ -33,13 +34,13 @@
 obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
 obj-$(CONFIG_PWM_OMAP_DMTIMER)	+= pwm-omap-dmtimer.o
 obj-$(CONFIG_PWM_PCA9685)	+= pwm-pca9685.o
-obj-$(CONFIG_PWM_PUV3)		+= pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)		+= pwm-pxa.o
 obj-$(CONFIG_PWM_RCAR)		+= pwm-rcar.o
 obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
+obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
@@ -50,7 +51,6 @@
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o
 obj-$(CONFIG_PWM_TIECAP)	+= pwm-tiecap.o
 obj-$(CONFIG_PWM_TIEHRPWM)	+= pwm-tiehrpwm.o
-obj-$(CONFIG_PWM_TIPWMSS)	+= pwm-tipwmss.o
 obj-$(CONFIG_PWM_TWL)		+= pwm-twl.o
 obj-$(CONFIG_PWM_TWL_LED)	+= pwm-twl-led.o
 obj-$(CONFIG_PWM_VT8500)	+= pwm-vt8500.o
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index f877e77..1f16f53 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -20,6 +20,9 @@
 
 #include <dt-bindings/pwm/pwm.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/pwm.h>
+
 #define MAX_PWMS 1024
 
 static DEFINE_MUTEX(pwm_lookup_lock);
@@ -114,6 +117,14 @@
 		}
 	}
 
+	if (pwm->chip->ops->get_state) {
+		pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
+		trace_pwm_get(pwm, &pwm->state);
+
+		if (IS_ENABLED(CONFIG_PWM_DEBUG))
+			pwm->last = pwm->state;
+	}
+
 	set_bit(PWMF_REQUESTED, &pwm->flags);
 	pwm->label = label;
 
@@ -224,17 +235,28 @@
 }
 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
 
-static bool pwm_ops_check(const struct pwm_ops *ops)
+static bool pwm_ops_check(const struct pwm_chip *chip)
 {
+
+	const struct pwm_ops *ops = chip->ops;
+
 	/* driver supports legacy, non-atomic operation */
-	if (ops->config && ops->enable && ops->disable)
-		return true;
+	if (ops->config && ops->enable && ops->disable) {
+		if (IS_ENABLED(CONFIG_PWM_DEBUG))
+			dev_warn(chip->dev,
+				 "Driver needs updating to atomic API\n");
 
-	/* driver supports atomic operation */
-	if (ops->apply)
 		return true;
+	}
 
-	return false;
+	if (!ops->apply)
+		return false;
+
+	if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
+		dev_warn(chip->dev,
+			 "Please implement the .get_state() callback\n");
+
+	return true;
 }
 
 /**
@@ -258,7 +280,7 @@
 	if (!chip || !chip->dev || !chip->ops || !chip->npwm)
 		return -EINVAL;
 
-	if (!pwm_ops_check(chip->ops))
+	if (!pwm_ops_check(chip))
 		return -EINVAL;
 
 	mutex_lock(&pwm_lock);
@@ -283,9 +305,6 @@
 		pwm->hwpwm = i;
 		pwm->state.polarity = polarity;
 
-		if (chip->ops->get_state)
-			chip->ops->get_state(chip, pwm, &pwm->state);
-
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
 
@@ -445,6 +464,107 @@
 }
 EXPORT_SYMBOL_GPL(pwm_free);
 
+static void pwm_apply_state_debug(struct pwm_device *pwm,
+				  const struct pwm_state *state)
+{
+	struct pwm_state *last = &pwm->last;
+	struct pwm_chip *chip = pwm->chip;
+	struct pwm_state s1, s2;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_PWM_DEBUG))
+		return;
+
+	/* No reasonable diagnosis possible without .get_state() */
+	if (!chip->ops->get_state)
+		return;
+
+	/*
+	 * *state was just applied. Read out the hardware state and do some
+	 * checks.
+	 */
+
+	chip->ops->get_state(chip, pwm, &s1);
+	trace_pwm_get(pwm, &s1);
+
+	/*
+	 * The lowlevel driver either ignored .polarity (which is a bug) or as
+	 * best effort inverted .polarity and fixed .duty_cycle respectively.
+	 * Undo this inversion and fixup for further tests.
+	 */
+	if (s1.enabled && s1.polarity != state->polarity) {
+		s2.polarity = state->polarity;
+		s2.duty_cycle = s1.period - s1.duty_cycle;
+		s2.period = s1.period;
+		s2.enabled = s1.enabled;
+	} else {
+		s2 = s1;
+	}
+
+	if (s2.polarity != state->polarity &&
+	    state->duty_cycle < state->period)
+		dev_warn(chip->dev, ".apply ignored .polarity\n");
+
+	if (state->enabled &&
+	    last->polarity == state->polarity &&
+	    last->period > s2.period &&
+	    last->period <= state->period)
+		dev_warn(chip->dev,
+			 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
+			 state->period, s2.period, last->period);
+
+	if (state->enabled && state->period < s2.period)
+		dev_warn(chip->dev,
+			 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
+			 state->period, s2.period);
+
+	if (state->enabled &&
+	    last->polarity == state->polarity &&
+	    last->period == s2.period &&
+	    last->duty_cycle > s2.duty_cycle &&
+	    last->duty_cycle <= state->duty_cycle)
+		dev_warn(chip->dev,
+			 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
+			 state->duty_cycle, state->period,
+			 s2.duty_cycle, s2.period,
+			 last->duty_cycle, last->period);
+
+	if (state->enabled && state->duty_cycle < s2.duty_cycle)
+		dev_warn(chip->dev,
+			 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
+			 state->duty_cycle, state->period,
+			 s2.duty_cycle, s2.period);
+
+	if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
+		dev_warn(chip->dev,
+			 "requested disabled, but yielded enabled with duty > 0\n");
+
+	/* reapply the state that the driver reported being configured. */
+	err = chip->ops->apply(chip, pwm, &s1);
+	if (err) {
+		*last = s1;
+		dev_err(chip->dev, "failed to reapply current setting\n");
+		return;
+	}
+
+	trace_pwm_apply(pwm, &s1);
+
+	chip->ops->get_state(chip, pwm, last);
+	trace_pwm_get(pwm, last);
+
+	/* reapplication of the current state should give an exact match */
+	if (s1.enabled != last->enabled ||
+	    s1.polarity != last->polarity ||
+	    (s1.enabled && s1.period != last->period) ||
+	    (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
+		dev_err(chip->dev,
+			".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
+			s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
+			last->enabled, last->polarity, last->duty_cycle,
+			last->period);
+	}
+}
+
 /**
  * pwm_apply_state() - atomically apply a new state to a PWM device
  * @pwm: PWM device
@@ -472,7 +592,15 @@
 		if (err)
 			return err;
 
+		trace_pwm_apply(pwm, state);
+
 		pwm->state = *state;
+
+		/*
+		 * only do this after pwm->state was applied as some
+		 * implementations of .get_state depend on this
+		 */
+		pwm_apply_state_debug(pwm, state);
 	} else {
 		/*
 		 * FIXME: restore the initial state in case of error.
@@ -1156,8 +1284,8 @@
 		if (state.enabled)
 			seq_puts(s, " enabled");
 
-		seq_printf(s, " period: %u ns", state.period);
-		seq_printf(s, " duty: %u ns", state.duty_cycle);
+		seq_printf(s, " period: %llu ns", state.period);
+		seq_printf(s, " duty: %llu ns", state.duty_cycle);
 		seq_printf(s, " polarity: %s",
 			   state.polarity ? "inverse" : "normal");
 
@@ -1199,30 +1327,19 @@
 	return 0;
 }
 
-static const struct seq_operations pwm_seq_ops = {
+static const struct seq_operations pwm_debugfs_sops = {
 	.start = pwm_seq_start,
 	.next = pwm_seq_next,
 	.stop = pwm_seq_stop,
 	.show = pwm_seq_show,
 };
 
-static int pwm_seq_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &pwm_seq_ops);
-}
-
-static const struct file_operations pwm_debugfs_ops = {
-	.owner = THIS_MODULE,
-	.open = pwm_seq_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = seq_release,
-};
+DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
 
 static int __init pwm_debugfs_init(void)
 {
 	debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
-			    &pwm_debugfs_ops);
+			    &pwm_debugfs_fops);
 
 	return 0;
 }
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 9ba7334..d7cb0df 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -4,6 +4,19 @@
  *
  * Copyright (C) 2013 Atmel Corporation
  *		 Bo Shen <voice.shen@atmel.com>
+ *
+ * Links to reference manuals for the supported PWM chips can be found in
+ * Documentation/arm/microchip.rst.
+ *
+ * Limitations:
+ * - Periods start with the inactive level.
+ * - Hardware has to be stopped in general to update settings.
+ *
+ * Software bugs/possible improvements:
+ * - When atmel_pwm_apply() is called with state->enabled=false a change in
+ *   state->polarity isn't honored.
+ * - Instead of sleeping to wait for a completed period, the interrupt
+ *   functionality could be used.
  */
 
 #include <linux/clk.h>
@@ -47,6 +60,8 @@
 #define PWMV2_CPRD		0x0C
 #define PWMV2_CPRDUPD		0x10
 
+#define PWM_MAX_PRES		10
+
 struct atmel_pwm_registers {
 	u8 period;
 	u8 period_upd;
@@ -55,8 +70,7 @@
 };
 
 struct atmel_pwm_config {
-	u32 max_period;
-	u32 max_pres;
+	u32 period_bits;
 };
 
 struct atmel_pwm_data {
@@ -97,7 +111,7 @@
 {
 	unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
 
-	return readl_relaxed(chip->base + base + offset);
+	return atmel_pwm_readl(chip, base + offset);
 }
 
 static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip,
@@ -106,7 +120,7 @@
 {
 	unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
 
-	writel_relaxed(val, chip->base + base + offset);
+	atmel_pwm_writel(chip, base + offset, val);
 }
 
 static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
@@ -115,17 +129,27 @@
 {
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 	unsigned long long cycles = state->period;
+	int shift;
 
 	/* Calculate the period cycles and prescale value */
 	cycles *= clk_get_rate(atmel_pwm->clk);
 	do_div(cycles, NSEC_PER_SEC);
 
-	for (*pres = 0; cycles > atmel_pwm->data->cfg.max_period; cycles >>= 1)
-		(*pres)++;
+	/*
+	 * The register for the period length is cfg.period_bits bits wide.
+	 * So for each bit the number of clock cycles is wider divide the input
+	 * clock frequency by two using pres and shift cprd accordingly.
+	 */
+	shift = fls(cycles) - atmel_pwm->data->cfg.period_bits;
 
-	if (*pres > atmel_pwm->data->cfg.max_pres) {
+	if (shift > PWM_MAX_PRES) {
 		dev_err(chip->dev, "pres exceeds the maximum value\n");
 		return -EINVAL;
+	} else if (shift > 0) {
+		*pres = shift;
+		cycles >>= *pres;
+	} else {
+		*pres = 0;
 	}
 
 	*cprd = cycles;
@@ -271,8 +295,48 @@
 	return 0;
 }
 
+static void atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	u32 sr, cmr;
+
+	sr = atmel_pwm_readl(atmel_pwm, PWM_SR);
+	cmr = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+
+	if (sr & (1 << pwm->hwpwm)) {
+		unsigned long rate = clk_get_rate(atmel_pwm->clk);
+		u32 cdty, cprd, pres;
+		u64 tmp;
+
+		pres = cmr & PWM_CMR_CPRE_MSK;
+
+		cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
+					  atmel_pwm->data->regs.period);
+		tmp = (u64)cprd * NSEC_PER_SEC;
+		tmp <<= pres;
+		state->period = DIV64_U64_ROUND_UP(tmp, rate);
+
+		cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
+					  atmel_pwm->data->regs.duty);
+		tmp = (u64)(cprd - cdty) * NSEC_PER_SEC;
+		tmp <<= pres;
+		state->duty_cycle = DIV64_U64_ROUND_UP(tmp, rate);
+
+		state->enabled = true;
+	} else {
+		state->enabled = false;
+	}
+
+	if (cmr & PWM_CMR_CPOL)
+		state->polarity = PWM_POLARITY_INVERSED;
+	else
+		state->polarity = PWM_POLARITY_NORMAL;
+}
+
 static const struct pwm_ops atmel_pwm_ops = {
 	.apply = atmel_pwm_apply,
+	.get_state = atmel_pwm_get_state,
 	.owner = THIS_MODULE,
 };
 
@@ -285,8 +349,7 @@
 	},
 	.cfg = {
 		/* 16 bits to keep period and duty. */
-		.max_period	= 0xffff,
-		.max_pres	= 10,
+		.period_bits	= 16,
 	},
 };
 
@@ -299,8 +362,7 @@
 	},
 	.cfg = {
 		/* 16 bits to keep period and duty. */
-		.max_period	= 0xffff,
-		.max_pres	= 10,
+		.period_bits	= 16,
 	},
 };
 
@@ -313,8 +375,7 @@
 	},
 	.cfg = {
 		/* 32 bits to keep period and duty. */
-		.max_period	= 0xffffffff,
-		.max_pres	= 10,
+		.period_bits	= 32,
 	},
 };
 
diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c
index d392a82..79b1e58 100644
--- a/drivers/pwm/pwm-bcm-iproc.c
+++ b/drivers/pwm/pwm-bcm-iproc.c
@@ -148,8 +148,7 @@
 		value = rate * state->duty_cycle;
 		duty = div64_u64(value, div);
 
-		if (period < IPROC_PWM_PERIOD_MIN ||
-		    duty < IPROC_PWM_DUTY_CYCLE_MIN)
+		if (period < IPROC_PWM_PERIOD_MIN)
 			return -EINVAL;
 
 		if (period <= IPROC_PWM_PERIOD_MAX &&
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index 81da91d..16c5898 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -138,7 +138,7 @@
 		dc = div64_u64(val, div);
 
 		/* If duty_ns or period_ns are not achievable then return */
-		if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
+		if (pc < PERIOD_COUNT_MIN)
 			return -EINVAL;
 
 		/* If pc and dc are in bounds, the calculation is done */
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index d78f86f..6841dcf 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -152,13 +152,9 @@
 		return PTR_ERR(pc->base);
 
 	pc->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(pc->clk)) {
-		ret = PTR_ERR(pc->clk);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "clock not found: %d\n", ret);
-
-		return ret;
-	}
+	if (IS_ERR(pc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+				     "clock not found\n");
 
 	ret = clk_prepare_enable(pc->clk);
 	if (ret)
diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c
index 924d39a..ba9500a 100644
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -43,7 +43,7 @@
 static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
 {
 	/* Duty cycle 0..15 max */
-	return DIV_ROUND_CLOSEST(v * 0xf, pwm->args.period);
+	return DIV64_U64_ROUND_CLOSEST(v * 0xf, pwm->args.period);
 }
 
 static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
index 272eeb0..ecfdfac 100644
--- a/drivers/pwm/pwm-crc.c
+++ b/drivers/pwm/pwm-crc.c
@@ -21,8 +21,8 @@
 
 #define PWM_MAX_LEVEL		0xFF
 
-#define PWM_BASE_CLK		6000000  /* 6 MHz */
-#define PWM_MAX_PERIOD_NS	21333    /* 46.875KHz */
+#define PWM_BASE_CLK_MHZ	6	/* 6 MHz */
+#define PWM_MAX_PERIOD_NS	5461334	/* 183 Hz */
 
 /**
  * struct crystalcove_pwm - Crystal Cove PWM controller
@@ -39,59 +39,121 @@
 	return container_of(pc, struct crystalcove_pwm, chip);
 }
 
-static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
+static int crc_pwm_calc_clk_div(int period_ns)
 {
-	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+	int clk_div;
 
-	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
+	clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_USEC);
+	/* clk_div 1 - 128, maps to register values 0-127 */
+	if (clk_div > 0)
+		clk_div--;
 
-	return 0;
+	return clk_div;
 }
 
-static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm)
+static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *state)
 {
-	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
-
-	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
-}
-
-static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
-			  int duty_ns, int period_ns)
-{
-	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip);
 	struct device *dev = crc_pwm->chip.dev;
-	int level;
+	int err;
 
-	if (period_ns > PWM_MAX_PERIOD_NS) {
+	if (state->period > PWM_MAX_PERIOD_NS) {
 		dev_err(dev, "un-supported period_ns\n");
 		return -EINVAL;
 	}
 
-	if (pwm_get_period(pwm) != period_ns) {
-		int clk_div;
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EOPNOTSUPP;
 
-		/* changing the clk divisor, need to disable fisrt */
-		crc_pwm_disable(c, pwm);
-		clk_div = PWM_BASE_CLK * period_ns / NSEC_PER_SEC;
-
-		regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
-					clk_div | PWM_OUTPUT_ENABLE);
-
-		/* enable back */
-		crc_pwm_enable(c, pwm);
+	if (pwm_is_enabled(pwm) && !state->enabled) {
+		err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
+		if (err) {
+			dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err);
+			return err;
+		}
 	}
 
-	/* change the pwm duty cycle */
-	level = duty_ns * PWM_MAX_LEVEL / period_ns;
-	regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+	if (pwm_get_duty_cycle(pwm) != state->duty_cycle ||
+	    pwm_get_period(pwm) != state->period) {
+		u64 level = state->duty_cycle * PWM_MAX_LEVEL;
+
+		do_div(level, state->period);
+
+		err = regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+		if (err) {
+			dev_err(dev, "Error writing PWM0_DUTY_CYCLE %d\n", err);
+			return err;
+		}
+	}
+
+	if (pwm_is_enabled(pwm) && state->enabled &&
+	    pwm_get_period(pwm) != state->period) {
+		/* changing the clk divisor, clear PWM_OUTPUT_ENABLE first */
+		err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0);
+		if (err) {
+			dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err);
+			return err;
+		}
+	}
+
+	if (pwm_get_period(pwm) != state->period ||
+	    pwm_is_enabled(pwm) != state->enabled) {
+		int clk_div = crc_pwm_calc_clk_div(state->period);
+		int pwm_output_enable = state->enabled ? PWM_OUTPUT_ENABLE : 0;
+
+		err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
+				   clk_div | pwm_output_enable);
+		if (err) {
+			dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err);
+			return err;
+		}
+	}
+
+	if (!pwm_is_enabled(pwm) && state->enabled) {
+		err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
+		if (err) {
+			dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err);
+			return err;
+		}
+	}
 
 	return 0;
 }
 
+static void crc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+			      struct pwm_state *state)
+{
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip);
+	struct device *dev = crc_pwm->chip.dev;
+	unsigned int clk_div, clk_div_reg, duty_cycle_reg;
+	int error;
+
+	error = regmap_read(crc_pwm->regmap, PWM0_CLK_DIV, &clk_div_reg);
+	if (error) {
+		dev_err(dev, "Error reading PWM0_CLK_DIV %d\n", error);
+		return;
+	}
+
+	error = regmap_read(crc_pwm->regmap, PWM0_DUTY_CYCLE, &duty_cycle_reg);
+	if (error) {
+		dev_err(dev, "Error reading PWM0_DUTY_CYCLE %d\n", error);
+		return;
+	}
+
+	clk_div = (clk_div_reg & ~PWM_OUTPUT_ENABLE) + 1;
+
+	state->period =
+		DIV_ROUND_UP(clk_div * NSEC_PER_USEC * 256, PWM_BASE_CLK_MHZ);
+	state->duty_cycle =
+		DIV_ROUND_UP_ULL(duty_cycle_reg * state->period, PWM_MAX_LEVEL);
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = !!(clk_div_reg & PWM_OUTPUT_ENABLE);
+}
+
 static const struct pwm_ops crc_pwm_ops = {
-	.config = crc_pwm_config,
-	.enable = crc_pwm_enable,
-	.disable = crc_pwm_disable,
+	.apply = crc_pwm_apply,
+	.get_state = crc_pwm_get_state,
 };
 
 static int crystalcove_pwm_probe(struct platform_device *pdev)
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 8949744..c1c3379 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -25,11 +25,39 @@
 	struct pwm_chip chip;
 };
 
+/**
+ * struct cros_ec_pwm - per-PWM driver data
+ * @duty_cycle: cached duty cycle
+ */
+struct cros_ec_pwm {
+	u16 duty_cycle;
+};
+
 static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *c)
 {
 	return container_of(c, struct cros_ec_pwm_device, chip);
 }
 
+static int cros_ec_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct cros_ec_pwm *channel;
+
+	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
+	if (!channel)
+		return -ENOMEM;
+
+	pwm_set_chip_data(pwm, channel);
+
+	return 0;
+}
+
+static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
+
+	kfree(channel);
+}
+
 static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
 {
 	struct {
@@ -53,8 +81,7 @@
 	return cros_ec_cmd_xfer_status(ec, msg);
 }
 
-static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index,
-				  u32 *result)
+static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
 {
 	struct {
 		struct cros_ec_command msg;
@@ -79,24 +106,19 @@
 	params->index = index;
 
 	ret = cros_ec_cmd_xfer_status(ec, msg);
-	if (result)
-		*result = msg->result;
 	if (ret < 0)
 		return ret;
 
 	return resp->duty;
 }
 
-static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
-{
-	return __cros_ec_pwm_get_duty(ec, index, NULL);
-}
-
 static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			     const struct pwm_state *state)
 {
 	struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
-	int duty_cycle;
+	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
+	u16 duty_cycle;
+	int ret;
 
 	/* The EC won't let us change the period */
 	if (state->period != EC_PWM_MAX_DUTY)
@@ -108,13 +130,20 @@
 	 */
 	duty_cycle = state->enabled ? state->duty_cycle : 0;
 
-	return cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
+	ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
+	if (ret < 0)
+		return ret;
+
+	channel->duty_cycle = state->duty_cycle;
+
+	return 0;
 }
 
 static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 				  struct pwm_state *state)
 {
 	struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
+	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
 	int ret;
 
 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm);
@@ -126,8 +155,19 @@
 	state->enabled = (ret > 0);
 	state->period = EC_PWM_MAX_DUTY;
 
-	/* Note that "disabled" and "duty cycle == 0" are treated the same */
-	state->duty_cycle = ret;
+	/*
+	 * Note that "disabled" and "duty cycle == 0" are treated the same. If
+	 * the cached duty cycle is not zero, used the cached duty cycle. This
+	 * ensures that the configured duty cycle is kept across a disable and
+	 * enable operation and avoids potentially confusing consumers.
+	 *
+	 * For the case of the initial hardware readout, channel->duty_cycle
+	 * will be 0 and the actual duty cycle read from the EC is used.
+	 */
+	if (ret == 0 && channel->duty_cycle > 0)
+		state->duty_cycle = channel->duty_cycle;
+	else
+		state->duty_cycle = ret;
 }
 
 static struct pwm_device *
@@ -149,34 +189,41 @@
 }
 
 static const struct pwm_ops cros_ec_pwm_ops = {
+	.request = cros_ec_pwm_request,
+	.free = cros_ec_pwm_free,
 	.get_state	= cros_ec_pwm_get_state,
 	.apply		= cros_ec_pwm_apply,
 	.owner		= THIS_MODULE,
 };
 
+/*
+ * Determine the number of supported PWMs. The EC does not return the number
+ * of PWMs it supports directly, so we have to read the pwm duty cycle for
+ * subsequent channels until we get an error.
+ */
 static int cros_ec_num_pwms(struct cros_ec_device *ec)
 {
 	int i, ret;
 
 	/* The index field is only 8 bits */
 	for (i = 0; i <= U8_MAX; i++) {
-		u32 result = 0;
-
-		ret = __cros_ec_pwm_get_duty(ec, i, &result);
-		/* We want to parse EC protocol errors */
-		if (ret < 0 && !(ret == -EPROTO && result))
-			return ret;
-
+		ret = cros_ec_pwm_get_duty(ec, i);
 		/*
 		 * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
 		 * responses; everything else is treated as an error.
+		 * The EC error codes map to -EOPNOTSUPP and -EINVAL,
+		 * so check for those.
 		 */
-		if (result == EC_RES_INVALID_COMMAND)
+		switch (ret) {
+		case -EOPNOTSUPP:	/* invalid command */
 			return -ENODEV;
-		else if (result == EC_RES_INVALID_PARAM)
+		case -EINVAL:		/* invalid parameter */
 			return i;
-		else if (result)
-			return -EPROTO;
+		default:
+			if (ret < 0)
+				return ret;
+			break;
+		}
 	}
 
 	return U8_MAX;
diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index 22c002e..37f9b68 100644
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c
@@ -329,23 +329,7 @@
 static int img_pwm_remove(struct platform_device *pdev)
 {
 	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);
-	u32 val;
-	unsigned int i;
-	int ret;
 
-	ret = pm_runtime_get_sync(&pdev->dev);
-	if (ret < 0) {
-		pm_runtime_put(&pdev->dev);
-		return ret;
-	}
-
-	for (i = 0; i < pwm_chip->chip.npwm; i++) {
-		val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
-		val &= ~BIT(i);
-		img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
-	}
-
-	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		img_pwm_runtime_suspend(&pdev->dev);
diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index 9145f61..fcdf6be 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -18,10 +18,8 @@
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/io.h>
-#include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
@@ -126,7 +124,7 @@
 		real_state->duty_cycle = state->duty_cycle;
 
 	tmp = (u64)p->mod * real_state->duty_cycle;
-	p->val = DIV_ROUND_CLOSEST_ULL(tmp, real_state->period);
+	p->val = DIV64_U64_ROUND_CLOSEST(tmp, real_state->period);
 
 	real_state->polarity = state->polarity;
 	real_state->enabled = state->enabled;
diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index ae11d85..86bcafd 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -18,7 +18,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
@@ -85,13 +84,19 @@
 	struct clk	*clk_per;
 	void __iomem	*mmio_base;
 	struct pwm_chip	chip;
+
+	/*
+	 * The driver cannot read the current duty cycle from the hardware if
+	 * the hardware is disabled. Cache the last programmed duty cycle
+	 * value to return in that case.
+	 */
+	unsigned int duty_cycle;
 };
 
 #define to_pwm_imx27_chip(chip)	container_of(chip, struct pwm_imx27_chip, chip)
 
-static int pwm_imx27_clk_prepare_enable(struct pwm_chip *chip)
+static int pwm_imx27_clk_prepare_enable(struct pwm_imx27_chip *imx)
 {
-	struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
 	int ret;
 
 	ret = clk_prepare_enable(imx->clk_ipg);
@@ -107,10 +112,8 @@
 	return 0;
 }
 
-static void pwm_imx27_clk_disable_unprepare(struct pwm_chip *chip)
+static void pwm_imx27_clk_disable_unprepare(struct pwm_imx27_chip *imx)
 {
-	struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
-
 	clk_disable_unprepare(imx->clk_per);
 	clk_disable_unprepare(imx->clk_ipg);
 }
@@ -123,7 +126,7 @@
 	u64 tmp;
 	int ret;
 
-	ret = pwm_imx27_clk_prepare_enable(chip);
+	ret = pwm_imx27_clk_prepare_enable(imx);
 	if (ret < 0)
 		return;
 
@@ -147,25 +150,26 @@
 
 	prescaler = MX3_PWMCR_PRESCALER_GET(val);
 	pwm_clk = clk_get_rate(imx->clk_per);
-	pwm_clk = DIV_ROUND_CLOSEST_ULL(pwm_clk, prescaler);
 	val = readl(imx->mmio_base + MX3_PWMPR);
 	period = val >= MX3_PWMPR_MAX ? MX3_PWMPR_MAX : val;
 
 	/* PWMOUT (Hz) = PWMCLK / (PWMPR + 2) */
-	tmp = NSEC_PER_SEC * (u64)(period + 2);
-	state->period = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk);
+	tmp = NSEC_PER_SEC * (u64)(period + 2) * prescaler;
+	state->period = DIV_ROUND_UP_ULL(tmp, pwm_clk);
 
-	/* PWMSAR can be read only if PWM is enabled */
-	if (state->enabled) {
+	/*
+	 * PWMSAR can be read only if PWM is enabled. If the PWM is disabled,
+	 * use the cached value.
+	 */
+	if (state->enabled)
 		val = readl(imx->mmio_base + MX3_PWMSAR);
-		tmp = NSEC_PER_SEC * (u64)(val);
-		state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk);
-	} else {
-		state->duty_cycle = 0;
-	}
+	else
+		val = imx->duty_cycle;
 
-	if (!state->enabled)
-		pwm_imx27_clk_disable_unprepare(chip);
+	tmp = NSEC_PER_SEC * (u64)(val) * prescaler;
+	state->duty_cycle = DIV_ROUND_UP_ULL(tmp, pwm_clk);
+
+	pwm_imx27_clk_disable_unprepare(imx);
 }
 
 static void pwm_imx27_sw_reset(struct pwm_chip *chip)
@@ -198,7 +202,7 @@
 	sr = readl(imx->mmio_base + MX3_PWMSR);
 	fifoav = FIELD_GET(MX3_PWMSR_FIFOAV, sr);
 	if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
-		period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
+		period_ms = DIV_ROUND_UP_ULL(pwm_get_period(pwm),
 					 NSEC_PER_MSEC);
 		msleep(period_ms);
 
@@ -215,68 +219,75 @@
 	struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
 	struct pwm_state cstate;
 	unsigned long long c;
+	unsigned long long clkrate;
 	int ret;
 	u32 cr;
 
 	pwm_get_state(pwm, &cstate);
 
-	if (state->enabled) {
-		c = clk_get_rate(imx->clk_per);
-		c *= state->period;
+	clkrate = clk_get_rate(imx->clk_per);
+	c = clkrate * state->period;
 
-		do_div(c, 1000000000);
-		period_cycles = c;
+	do_div(c, NSEC_PER_SEC);
+	period_cycles = c;
 
-		prescale = period_cycles / 0x10000 + 1;
+	prescale = period_cycles / 0x10000 + 1;
 
-		period_cycles /= prescale;
-		c = (unsigned long long)period_cycles * state->duty_cycle;
-		do_div(c, state->period);
-		duty_cycles = c;
+	period_cycles /= prescale;
+	c = clkrate * state->duty_cycle;
+	do_div(c, NSEC_PER_SEC);
+	duty_cycles = c;
+	duty_cycles /= prescale;
 
-		/*
-		 * according to imx pwm RM, the real period value should be
-		 * PERIOD value in PWMPR plus 2.
-		 */
-		if (period_cycles > 2)
-			period_cycles -= 2;
-		else
-			period_cycles = 0;
+	/*
+	 * according to imx pwm RM, the real period value should be PERIOD
+	 * value in PWMPR plus 2.
+	 */
+	if (period_cycles > 2)
+		period_cycles -= 2;
+	else
+		period_cycles = 0;
 
-		/*
-		 * Wait for a free FIFO slot if the PWM is already enabled, and
-		 * flush the FIFO if the PWM was disabled and is about to be
-		 * enabled.
-		 */
-		if (cstate.enabled) {
-			pwm_imx27_wait_fifo_slot(chip, pwm);
-		} else {
-			ret = pwm_imx27_clk_prepare_enable(chip);
-			if (ret)
-				return ret;
+	/*
+	 * Wait for a free FIFO slot if the PWM is already enabled, and flush
+	 * the FIFO if the PWM was disabled and is about to be enabled.
+	 */
+	if (cstate.enabled) {
+		pwm_imx27_wait_fifo_slot(chip, pwm);
+	} else {
+		ret = pwm_imx27_clk_prepare_enable(imx);
+		if (ret)
+			return ret;
 
-			pwm_imx27_sw_reset(chip);
-		}
-
-		writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
-		writel(period_cycles, imx->mmio_base + MX3_PWMPR);
-
-		cr = MX3_PWMCR_PRESCALER_SET(prescale) |
-		     MX3_PWMCR_STOPEN | MX3_PWMCR_DOZEN | MX3_PWMCR_WAITEN |
-		     FIELD_PREP(MX3_PWMCR_CLKSRC, MX3_PWMCR_CLKSRC_IPG_HIGH) |
-		     MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
-
-		if (state->polarity == PWM_POLARITY_INVERSED)
-			cr |= FIELD_PREP(MX3_PWMCR_POUTC,
-					MX3_PWMCR_POUTC_INVERTED);
-
-		writel(cr, imx->mmio_base + MX3_PWMCR);
-	} else if (cstate.enabled) {
-		writel(0, imx->mmio_base + MX3_PWMCR);
-
-		pwm_imx27_clk_disable_unprepare(chip);
+		pwm_imx27_sw_reset(chip);
 	}
 
+	writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+	writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+	/*
+	 * Store the duty cycle for future reference in cases where the
+	 * MX3_PWMSAR register can't be read (i.e. when the PWM is disabled).
+	 */
+	imx->duty_cycle = duty_cycles;
+
+	cr = MX3_PWMCR_PRESCALER_SET(prescale) |
+	     MX3_PWMCR_STOPEN | MX3_PWMCR_DOZEN | MX3_PWMCR_WAITEN |
+	     FIELD_PREP(MX3_PWMCR_CLKSRC, MX3_PWMCR_CLKSRC_IPG_HIGH) |
+	     MX3_PWMCR_DBGEN;
+
+	if (state->polarity == PWM_POLARITY_INVERSED)
+		cr |= FIELD_PREP(MX3_PWMCR_POUTC,
+				MX3_PWMCR_POUTC_INVERTED);
+
+	if (state->enabled)
+		cr |= MX3_PWMCR_EN;
+
+	writel(cr, imx->mmio_base + MX3_PWMCR);
+
+	if (!state->enabled)
+		pwm_imx27_clk_disable_unprepare(imx);
+
 	return 0;
 }
 
@@ -295,6 +306,8 @@
 static int pwm_imx27_probe(struct platform_device *pdev)
 {
 	struct pwm_imx27_chip *imx;
+	int ret;
+	u32 pwmcr;
 
 	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
 	if (imx == NULL)
@@ -304,9 +317,13 @@
 
 	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
 	if (IS_ERR(imx->clk_ipg)) {
-		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
-				PTR_ERR(imx->clk_ipg));
-		return PTR_ERR(imx->clk_ipg);
+		int ret = PTR_ERR(imx->clk_ipg);
+
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"getting ipg clock failed with %d\n",
+				ret);
+		return ret;
 	}
 
 	imx->clk_per = devm_clk_get(&pdev->dev, "per");
@@ -333,6 +350,15 @@
 	if (IS_ERR(imx->mmio_base))
 		return PTR_ERR(imx->mmio_base);
 
+	ret = pwm_imx27_clk_prepare_enable(imx);
+	if (ret)
+		return ret;
+
+	/* keep clks on if pwm is running */
+	pwmcr = readl(imx->mmio_base + MX3_PWMCR);
+	if (!(pwmcr & MX3_PWMCR_EN))
+		pwm_imx27_clk_disable_unprepare(imx);
+
 	return pwmchip_add(&imx->chip);
 }
 
@@ -342,8 +368,6 @@
 
 	imx = platform_get_drvdata(pdev);
 
-	pwm_imx27_clk_disable_unprepare(&imx->chip);
-
 	return pwmchip_remove(&imx->chip);
 }
 
diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c
new file mode 100644
index 0000000..3e967a1
--- /dev/null
+++ b/drivers/pwm/pwm-iqs620a.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Azoteq IQS620A PWM Generator
+ *
+ * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
+ *
+ * Limitations:
+ * - The period is fixed to 1 ms and is generated continuously despite changes
+ *   to the duty cycle or enable/disable state.
+ * - Changes to the duty cycle or enable/disable state take effect immediately
+ *   and may result in a glitch during the period in which the change is made.
+ * - The device cannot generate a 0% duty cycle. For duty cycles below 1 / 256
+ *   ms, the output is disabled and relies upon an external pull-down resistor
+ *   to hold the GPIO3/LTX pin low.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mfd/iqs62x.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define IQS620_PWR_SETTINGS			0xd2
+#define IQS620_PWR_SETTINGS_PWM_OUT		BIT(7)
+
+#define IQS620_PWM_DUTY_CYCLE			0xd8
+
+#define IQS620_PWM_PERIOD_NS			1000000
+
+struct iqs620_pwm_private {
+	struct iqs62x_core *iqs62x;
+	struct pwm_chip chip;
+	struct notifier_block notifier;
+	struct mutex lock;
+	bool out_en;
+	u8 duty_val;
+};
+
+static int iqs620_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct iqs620_pwm_private *iqs620_pwm;
+	struct iqs62x_core *iqs62x;
+	unsigned int duty_cycle;
+	unsigned int duty_scale;
+	int ret;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -ENOTSUPP;
+
+	if (state->period < IQS620_PWM_PERIOD_NS)
+		return -EINVAL;
+
+	iqs620_pwm = container_of(chip, struct iqs620_pwm_private, chip);
+	iqs62x = iqs620_pwm->iqs62x;
+
+	/*
+	 * The duty cycle generated by the device is calculated as follows:
+	 *
+	 * duty_cycle = (IQS620_PWM_DUTY_CYCLE + 1) / 256 * 1 ms
+	 *
+	 * ...where IQS620_PWM_DUTY_CYCLE is a register value between 0 and 255
+	 * (inclusive). Therefore the lowest duty cycle the device can generate
+	 * while the output is enabled is 1 / 256 ms.
+	 *
+	 * For lower duty cycles (e.g. 0), the PWM output is simply disabled to
+	 * allow an external pull-down resistor to hold the GPIO3/LTX pin low.
+	 */
+	duty_cycle = min_t(u64, state->duty_cycle, IQS620_PWM_PERIOD_NS);
+	duty_scale = duty_cycle * 256 / IQS620_PWM_PERIOD_NS;
+
+	mutex_lock(&iqs620_pwm->lock);
+
+	if (!state->enabled || !duty_scale) {
+		ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
+					 IQS620_PWR_SETTINGS_PWM_OUT, 0);
+		if (ret)
+			goto err_mutex;
+	}
+
+	if (duty_scale) {
+		u8 duty_val = duty_scale - 1;
+
+		ret = regmap_write(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE,
+				   duty_val);
+		if (ret)
+			goto err_mutex;
+
+		iqs620_pwm->duty_val = duty_val;
+	}
+
+	if (state->enabled && duty_scale) {
+		ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
+					 IQS620_PWR_SETTINGS_PWM_OUT, 0xff);
+		if (ret)
+			goto err_mutex;
+	}
+
+	iqs620_pwm->out_en = state->enabled;
+
+err_mutex:
+	mutex_unlock(&iqs620_pwm->lock);
+
+	return ret;
+}
+
+static void iqs620_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	struct iqs620_pwm_private *iqs620_pwm;
+
+	iqs620_pwm = container_of(chip, struct iqs620_pwm_private, chip);
+
+	mutex_lock(&iqs620_pwm->lock);
+
+	/*
+	 * Since the device cannot generate a 0% duty cycle, requests to do so
+	 * cause subsequent calls to iqs620_pwm_get_state to report the output
+	 * as disabled with duty cycle equal to that which was in use prior to
+	 * the request. This is not ideal, but is the best compromise based on
+	 * the capabilities of the device.
+	 */
+	state->enabled = iqs620_pwm->out_en;
+	state->duty_cycle = DIV_ROUND_UP((iqs620_pwm->duty_val + 1) *
+					 IQS620_PWM_PERIOD_NS, 256);
+
+	mutex_unlock(&iqs620_pwm->lock);
+
+	state->period = IQS620_PWM_PERIOD_NS;
+}
+
+static int iqs620_pwm_notifier(struct notifier_block *notifier,
+			       unsigned long event_flags, void *context)
+{
+	struct iqs620_pwm_private *iqs620_pwm;
+	struct iqs62x_core *iqs62x;
+	int ret;
+
+	if (!(event_flags & BIT(IQS62X_EVENT_SYS_RESET)))
+		return NOTIFY_DONE;
+
+	iqs620_pwm = container_of(notifier, struct iqs620_pwm_private,
+				  notifier);
+	iqs62x = iqs620_pwm->iqs62x;
+
+	mutex_lock(&iqs620_pwm->lock);
+
+	/*
+	 * The parent MFD driver already prints an error message in the event
+	 * of a device reset, so nothing else is printed here unless there is
+	 * an additional failure.
+	 */
+	ret = regmap_write(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE,
+			   iqs620_pwm->duty_val);
+	if (ret)
+		goto err_mutex;
+
+	ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
+				 IQS620_PWR_SETTINGS_PWM_OUT,
+				 iqs620_pwm->out_en ? 0xff : 0);
+
+err_mutex:
+	mutex_unlock(&iqs620_pwm->lock);
+
+	if (ret) {
+		dev_err(iqs620_pwm->chip.dev,
+			"Failed to re-initialize device: %d\n", ret);
+		return NOTIFY_BAD;
+	}
+
+	return NOTIFY_OK;
+}
+
+static const struct pwm_ops iqs620_pwm_ops = {
+	.apply = iqs620_pwm_apply,
+	.get_state = iqs620_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static void iqs620_pwm_notifier_unregister(void *context)
+{
+	struct iqs620_pwm_private *iqs620_pwm = context;
+	int ret;
+
+	ret = blocking_notifier_chain_unregister(&iqs620_pwm->iqs62x->nh,
+						 &iqs620_pwm->notifier);
+	if (ret)
+		dev_err(iqs620_pwm->chip.dev,
+			"Failed to unregister notifier: %d\n", ret);
+}
+
+static int iqs620_pwm_probe(struct platform_device *pdev)
+{
+	struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
+	struct iqs620_pwm_private *iqs620_pwm;
+	unsigned int val;
+	int ret;
+
+	iqs620_pwm = devm_kzalloc(&pdev->dev, sizeof(*iqs620_pwm), GFP_KERNEL);
+	if (!iqs620_pwm)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, iqs620_pwm);
+	iqs620_pwm->iqs62x = iqs62x;
+
+	ret = regmap_read(iqs62x->regmap, IQS620_PWR_SETTINGS, &val);
+	if (ret)
+		return ret;
+	iqs620_pwm->out_en = val & IQS620_PWR_SETTINGS_PWM_OUT;
+
+	ret = regmap_read(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE, &val);
+	if (ret)
+		return ret;
+	iqs620_pwm->duty_val = val;
+
+	iqs620_pwm->chip.dev = &pdev->dev;
+	iqs620_pwm->chip.ops = &iqs620_pwm_ops;
+	iqs620_pwm->chip.base = -1;
+	iqs620_pwm->chip.npwm = 1;
+
+	mutex_init(&iqs620_pwm->lock);
+
+	iqs620_pwm->notifier.notifier_call = iqs620_pwm_notifier;
+	ret = blocking_notifier_chain_register(&iqs620_pwm->iqs62x->nh,
+					       &iqs620_pwm->notifier);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       iqs620_pwm_notifier_unregister,
+				       iqs620_pwm);
+	if (ret)
+		return ret;
+
+	ret = pwmchip_add(&iqs620_pwm->chip);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to add device: %d\n", ret);
+
+	return ret;
+}
+
+static int iqs620_pwm_remove(struct platform_device *pdev)
+{
+	struct iqs620_pwm_private *iqs620_pwm = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pwmchip_remove(&iqs620_pwm->chip);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to remove device: %d\n", ret);
+
+	return ret;
+}
+
+static struct platform_driver iqs620_pwm_platform_driver = {
+	.driver = {
+		.name = "iqs620a-pwm",
+	},
+	.probe = iqs620_pwm_probe,
+	.remove = iqs620_pwm_remove,
+};
+module_platform_driver(iqs620_pwm_platform_driver);
+
+MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
+MODULE_DESCRIPTION("Azoteq IQS620A PWM Generator");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:iqs620a-pwm");
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index 77c2831..00c642f 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -6,25 +6,27 @@
  * Limitations:
  * - The .apply callback doesn't complete the currently running period before
  *   reconfiguring the hardware.
- * - Each period starts with the inactive part.
  */
 
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/kernel.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
+#include <linux/regmap.h>
 
-#include <asm/mach-jz4740/timer.h>
-
-#define NUM_PWM 8
+struct soc_info {
+	unsigned int num_pwms;
+};
 
 struct jz4740_pwm_chip {
 	struct pwm_chip chip;
-	struct clk *clk;
+	struct regmap *map;
 };
 
 static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
@@ -32,111 +34,179 @@
 	return container_of(chip, struct jz4740_pwm_chip, chip);
 }
 
+static bool jz4740_pwm_can_use_chn(struct jz4740_pwm_chip *jz,
+				   unsigned int channel)
+{
+	/* Enable all TCU channels for PWM use by default except channels 0/1 */
+	u32 pwm_channels_mask = GENMASK(jz->chip.npwm - 1, 2);
+
+	device_property_read_u32(jz->chip.dev->parent,
+				 "ingenic,pwm-channels-mask",
+				 &pwm_channels_mask);
+
+	return !!(pwm_channels_mask & BIT(channel));
+}
+
 static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	/*
-	 * Timers 0 and 1 are used for system tasks, so they are unavailable
-	 * for use as PWMs.
-	 */
-	if (pwm->hwpwm < 2)
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
+	struct clk *clk;
+	char name[16];
+	int err;
+
+	if (!jz4740_pwm_can_use_chn(jz, pwm->hwpwm))
 		return -EBUSY;
 
-	jz4740_timer_start(pwm->hwpwm);
+	snprintf(name, sizeof(name), "timer%u", pwm->hwpwm);
+
+	clk = clk_get(chip->dev, name);
+	if (IS_ERR(clk))
+		return dev_err_probe(chip->dev, PTR_ERR(clk),
+				     "Failed to get clock\n");
+
+	err = clk_prepare_enable(clk);
+	if (err < 0) {
+		clk_put(clk);
+		return err;
+	}
+
+	pwm_set_chip_data(pwm, clk);
 
 	return 0;
 }
 
 static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	jz4740_timer_set_ctrl(pwm->hwpwm, 0);
+	struct clk *clk = pwm_get_chip_data(pwm);
 
-	jz4740_timer_stop(pwm->hwpwm);
+	clk_disable_unprepare(clk);
+	clk_put(clk);
 }
 
 static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
 
-	ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-	jz4740_timer_enable(pwm->hwpwm);
+	/* Enable PWM output */
+	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+			   TCU_TCSR_PWM_EN, TCU_TCSR_PWM_EN);
+
+	/* Start counter */
+	regmap_write(jz->map, TCU_REG_TESR, BIT(pwm->hwpwm));
 
 	return 0;
 }
 
 static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
 
 	/*
 	 * Set duty > period. This trick allows the TCU channels in TCU2 mode to
 	 * properly return to their init level.
 	 */
-	jz4740_timer_set_duty(pwm->hwpwm, 0xffff);
-	jz4740_timer_set_period(pwm->hwpwm, 0x0);
+	regmap_write(jz->map, TCU_REG_TDHRc(pwm->hwpwm), 0xffff);
+	regmap_write(jz->map, TCU_REG_TDFRc(pwm->hwpwm), 0x0);
 
 	/*
 	 * Disable PWM output.
 	 * In TCU2 mode (channel 1/2 on JZ4750+), this must be done before the
 	 * counter is stopped, while in TCU1 mode the order does not matter.
 	 */
-	ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+			   TCU_TCSR_PWM_EN, 0);
 
 	/* Stop counter */
-	jz4740_timer_disable(pwm->hwpwm);
+	regmap_write(jz->map, TCU_REG_TECR, BIT(pwm->hwpwm));
 }
 
 static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			    const struct pwm_state *state)
 {
 	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
-	unsigned long long tmp;
-	unsigned long rate, period, duty;
-	unsigned int prescaler = 0;
-	uint16_t ctrl;
+	unsigned long long tmp = 0xffffull * NSEC_PER_SEC;
+	struct clk *clk = pwm_get_chip_data(pwm);
+	unsigned long period, duty;
+	long rate;
+	int err;
 
-	rate = clk_get_rate(jz4740->clk);
-	tmp = rate * state->period;
-	do_div(tmp, 1000000000);
-	period = tmp;
+	/*
+	 * Limit the clock to a maximum rate that still gives us a period value
+	 * which fits in 16 bits.
+	 */
+	do_div(tmp, state->period);
 
-	while (period > 0xffff && prescaler < 6) {
-		period >>= 2;
-		++prescaler;
+	/*
+	 * /!\ IMPORTANT NOTE:
+	 * -------------------
+	 * This code relies on the fact that clk_round_rate() will always round
+	 * down, which is not a valid assumption given by the clk API, but only
+	 * happens to be true with the clk drivers used for Ingenic SoCs.
+	 *
+	 * Right now, there is no alternative as the clk API does not have a
+	 * round-down function (and won't have one for a while), but if it ever
+	 * comes to light, a round-down function should be used instead.
+	 */
+	rate = clk_round_rate(clk, tmp);
+	if (rate < 0) {
+		dev_err(chip->dev, "Unable to round rate: %ld", rate);
+		return rate;
 	}
 
-	if (prescaler == 6)
-		return -EINVAL;
+	/* Calculate period value */
+	tmp = (unsigned long long)rate * state->period;
+	do_div(tmp, NSEC_PER_SEC);
+	period = tmp;
 
+	/* Calculate duty value */
 	tmp = (unsigned long long)rate * state->duty_cycle;
 	do_div(tmp, NSEC_PER_SEC);
-	duty = period - tmp;
+	duty = tmp;
 
 	if (duty >= period)
 		duty = period - 1;
 
 	jz4740_pwm_disable(chip, pwm);
 
-	jz4740_timer_set_count(pwm->hwpwm, 0);
-	jz4740_timer_set_duty(pwm->hwpwm, duty);
-	jz4740_timer_set_period(pwm->hwpwm, period);
-
-	ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
-		JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
-
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-
-	switch (state->polarity) {
-	case PWM_POLARITY_NORMAL:
-		ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
-		break;
-	case PWM_POLARITY_INVERSED:
-		ctrl |= JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
-		break;
+	err = clk_set_rate(clk, rate);
+	if (err) {
+		dev_err(chip->dev, "Unable to set rate: %d", err);
+		return err;
 	}
 
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+	/* Reset counter to 0 */
+	regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);
+
+	/* Set duty */
+	regmap_write(jz4740->map, TCU_REG_TDHRc(pwm->hwpwm), duty);
+
+	/* Set period */
+	regmap_write(jz4740->map, TCU_REG_TDFRc(pwm->hwpwm), period);
+
+	/* Set abrupt shutdown */
+	regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+			   TCU_TCSR_PWM_SD, TCU_TCSR_PWM_SD);
+
+	/*
+	 * Set polarity.
+	 *
+	 * The PWM starts in inactive state until the internal timer reaches the
+	 * duty value, then becomes active until the timer reaches the period
+	 * value. In theory, we should then use (period - duty) as the real duty
+	 * value, as a high duty value would otherwise result in the PWM pin
+	 * being inactive most of the time.
+	 *
+	 * Here, we don't do that, and instead invert the polarity of the PWM
+	 * when it is active. This trick makes the PWM start with its active
+	 * state instead of its inactive state.
+	 */
+	if ((state->polarity == PWM_POLARITY_NORMAL) ^ state->enabled)
+		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+				   TCU_TCSR_PWM_INITL_HIGH, 0);
+	else
+		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+				   TCU_TCSR_PWM_INITL_HIGH,
+				   TCU_TCSR_PWM_INITL_HIGH);
 
 	if (state->enabled)
 		jz4740_pwm_enable(chip, pwm);
@@ -153,19 +223,27 @@
 
 static int jz4740_pwm_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct jz4740_pwm_chip *jz4740;
+	const struct soc_info *info;
 
-	jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
+	info = device_get_match_data(dev);
+	if (!info)
+		return -EINVAL;
+
+	jz4740 = devm_kzalloc(dev, sizeof(*jz4740), GFP_KERNEL);
 	if (!jz4740)
 		return -ENOMEM;
 
-	jz4740->clk = devm_clk_get(&pdev->dev, "ext");
-	if (IS_ERR(jz4740->clk))
-		return PTR_ERR(jz4740->clk);
+	jz4740->map = device_node_to_regmap(dev->parent->of_node);
+	if (IS_ERR(jz4740->map)) {
+		dev_err(dev, "regmap not found: %ld\n", PTR_ERR(jz4740->map));
+		return PTR_ERR(jz4740->map);
+	}
 
-	jz4740->chip.dev = &pdev->dev;
+	jz4740->chip.dev = dev;
 	jz4740->chip.ops = &jz4740_pwm_ops;
-	jz4740->chip.npwm = NUM_PWM;
+	jz4740->chip.npwm = info->num_pwms;
 	jz4740->chip.base = -1;
 	jz4740->chip.of_xlate = of_pwm_xlate_with_flags;
 	jz4740->chip.of_pwm_n_cells = 3;
@@ -182,9 +260,18 @@
 	return pwmchip_remove(&jz4740->chip);
 }
 
+static const struct soc_info __maybe_unused jz4740_soc_info = {
+	.num_pwms = 8,
+};
+
+static const struct soc_info __maybe_unused jz4725b_soc_info = {
+	.num_pwms = 6,
+};
+
 #ifdef CONFIG_OF
 static const struct of_device_id jz4740_pwm_dt_ids[] = {
-	{ .compatible = "ingenic,jz4740-pwm", },
+	{ .compatible = "ingenic,jz4740-pwm", .data = &jz4740_soc_info },
+	{ .compatible = "ingenic,jz4725b-pwm", .data = &jz4725b_soc_info },
 	{},
 };
 MODULE_DEVICE_TABLE(of, jz4740_pwm_dt_ids);
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index 710d9a2..522f862 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -120,17 +120,17 @@
 	lpc32xx->chip.npwm = 1;
 	lpc32xx->chip.base = -1;
 
+	/* If PWM is disabled, configure the output to the default value */
+	val = readl(lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
+	val &= ~PWM_PIN_LEVEL;
+	writel(val, lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
+
 	ret = pwmchip_add(&lpc32xx->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
 		return ret;
 	}
 
-	/* When PWM is disable, configure the output to the default value */
-	val = readl(lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
-	val &= ~PWM_PIN_LEVEL;
-	writel(val, lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
-
 	platform_set_drvdata(pdev, lpc32xx);
 
 	return 0;
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c
index 48f34d2..c6502cf 100644
--- a/drivers/pwm/pwm-lpss-platform.c
+++ b/drivers/pwm/pwm-lpss-platform.c
@@ -89,7 +89,6 @@
 
 static const struct dev_pm_ops pwm_lpss_platform_pm_ops = {
 	.prepare = pwm_lpss_prepare,
-	SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume)
 };
 
 static const struct acpi_device_id pwm_lpss_acpi_match[] = {
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index d77cec2..3444c56 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -85,7 +85,7 @@
 	unsigned long long on_time_div;
 	unsigned long c = lpwm->info->clk_rate, base_unit_range;
 	unsigned long long base_unit, freq = NSEC_PER_SEC;
-	u32 orig_ctrl, ctrl;
+	u32 ctrl;
 
 	do_div(freq, period_ns);
 
@@ -104,16 +104,14 @@
 	do_div(on_time_div, period_ns);
 	on_time_div = 255ULL - on_time_div;
 
-	orig_ctrl = ctrl = pwm_lpss_read(pwm);
+	ctrl = pwm_lpss_read(pwm);
 	ctrl &= ~PWM_ON_TIME_DIV_MASK;
 	ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
 	ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
 	ctrl |= on_time_div;
 
-	if (orig_ctrl != ctrl) {
-		pwm_lpss_write(pwm, ctrl);
-		pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
-	}
+	pwm_lpss_write(pwm, ctrl);
+	pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
 }
 
 static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
@@ -122,44 +120,49 @@
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
 }
 
+static int pwm_lpss_prepare_enable(struct pwm_lpss_chip *lpwm,
+				   struct pwm_device *pwm,
+				   const struct pwm_state *state)
+{
+	int ret;
+
+	ret = pwm_lpss_is_updating(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+	pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
+	ret = pwm_lpss_wait_for_update(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
+	return 0;
+}
+
 static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			  const struct pwm_state *state)
 {
 	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
-	int ret;
+	int ret = 0;
 
 	if (state->enabled) {
 		if (!pwm_is_enabled(pwm)) {
 			pm_runtime_get_sync(chip->dev);
-			ret = pwm_lpss_is_updating(pwm);
-			if (ret) {
-				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
-			ret = pwm_lpss_wait_for_update(pwm);
-			if (ret) {
-				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
-		} else {
-			ret = pwm_lpss_is_updating(pwm);
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
 			if (ret)
-				return ret;
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			return pwm_lpss_wait_for_update(pwm);
+				pm_runtime_put(chip->dev);
+		} else {
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
 		}
 	} else if (pwm_is_enabled(pwm)) {
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
 		pm_runtime_put(chip->dev);
 	}
 
-	return 0;
+	return ret;
 }
 
-/* This function gets called once from pwmchip_add to get the initial state */
 static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 			       struct pwm_state *state)
 {
@@ -168,6 +171,8 @@
 	unsigned long long base_unit, freq, on_time_div;
 	u32 ctrl;
 
+	pm_runtime_get_sync(chip->dev);
+
 	base_unit_range = BIT(lpwm->info->base_unit_bits);
 
 	ctrl = pwm_lpss_read(pwm);
@@ -188,8 +193,7 @@
 	state->polarity = PWM_POLARITY_NORMAL;
 	state->enabled = !!(ctrl & PWM_ENABLE);
 
-	if (state->enabled)
-		pm_runtime_get(chip->dev);
+	pm_runtime_put(chip->dev);
 }
 
 static const struct pwm_ops pwm_lpss_ops = {
@@ -203,7 +207,8 @@
 {
 	struct pwm_lpss_chip *lpwm;
 	unsigned long c;
-	int ret;
+	int i, ret;
+	u32 ctrl;
 
 	if (WARN_ON(info->npwm > MAX_PWMS))
 		return ERR_PTR(-ENODEV);
@@ -233,6 +238,12 @@
 		return ERR_PTR(ret);
 	}
 
+	for (i = 0; i < lpwm->info->npwm; i++) {
+		ctrl = pwm_lpss_read(&lpwm->chip.pwms[i]);
+		if (ctrl & PWM_ENABLE)
+			pm_runtime_get(dev);
+	}
+
 	return lpwm;
 }
 EXPORT_SYMBOL_GPL(pwm_lpss_probe);
@@ -249,30 +260,6 @@
 }
 EXPORT_SYMBOL_GPL(pwm_lpss_remove);
 
-int pwm_lpss_suspend(struct device *dev)
-{
-	struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
-	int i;
-
-	for (i = 0; i < lpwm->info->npwm; i++)
-		lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_suspend);
-
-int pwm_lpss_resume(struct device *dev)
-{
-	struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
-	int i;
-
-	for (i = 0; i < lpwm->info->npwm; i++)
-		writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_resume);
-
 MODULE_DESCRIPTION("PWM driver for Intel LPSS");
 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h
index 7909fa1..70db7e3 100644
--- a/drivers/pwm/pwm-lpss.h
+++ b/drivers/pwm/pwm-lpss.h
@@ -19,7 +19,6 @@
 	struct pwm_chip chip;
 	void __iomem *regs;
 	const struct pwm_lpss_boardinfo *info;
-	u32 saved_ctrl[MAX_PWMS];
 };
 
 struct pwm_lpss_boardinfo {
@@ -37,7 +36,5 @@
 struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
 				     const struct pwm_lpss_boardinfo *info);
 int pwm_lpss_remove(struct pwm_lpss_chip *lpwm);
-int pwm_lpss_suspend(struct device *dev);
-int pwm_lpss_resume(struct device *dev);
 
 #endif	/* __PWM_LPSS_H */
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index b94e0d0..ab001ce 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -46,6 +46,7 @@
  * @clk_main: the clock used by PWM core
  * @clk_pwms: the clock used by each PWM channel
  * @clk_freq: the fix clock frequency of legacy MIPS SoC
+ * @soc: pointer to chip's platform data
  */
 struct pwm_mediatek_chip {
 	struct pwm_chip chip;
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 6245bbd..bd0d733 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -136,7 +136,7 @@
 			dev_err(dev, "failed to set parent %s for %s: %d\n",
 				__clk_get_name(channel->clk_parent),
 				__clk_get_name(channel->clk), err);
-				return err;
+			return err;
 		}
 	}
 
@@ -163,7 +163,7 @@
 {
 	struct meson_pwm_channel *channel = pwm_get_chip_data(pwm);
 	unsigned int duty, period, pre_div, cnt, duty_cnt;
-	unsigned long fin_freq = -1;
+	unsigned long fin_freq;
 
 	duty = state->duty_cycle;
 	period = state->period;
diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
index b14376b..41bdbe7 100644
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -9,7 +9,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
@@ -25,12 +24,16 @@
 #define  PERIOD_PERIOD(p)	((p) & 0xffff)
 #define  PERIOD_PERIOD_MAX	0x10000
 #define  PERIOD_ACTIVE_HIGH	(3 << 16)
+#define  PERIOD_ACTIVE_LOW	(2 << 16)
+#define  PERIOD_INACTIVE_HIGH	(3 << 18)
 #define  PERIOD_INACTIVE_LOW	(2 << 18)
+#define  PERIOD_POLARITY_NORMAL	(PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW)
+#define  PERIOD_POLARITY_INVERSE	(PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH)
 #define  PERIOD_CDIV(div)	(((div) & 0x7) << 20)
 #define  PERIOD_CDIV_MAX	8
 
-static const unsigned int cdiv[PERIOD_CDIV_MAX] = {
-	1, 2, 4, 8, 16, 64, 256, 1024
+static const u8 cdiv_shift[PERIOD_CDIV_MAX] = {
+	0, 1, 2, 3, 4, 6, 8, 10
 };
 
 struct mxs_pwm_chip {
@@ -41,19 +44,34 @@
 
 #define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)
 
-static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
-			  int duty_ns, int period_ns)
+static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *state)
 {
 	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
 	int ret, div = 0;
 	unsigned int period_cycles, duty_cycles;
 	unsigned long rate;
 	unsigned long long c;
+	unsigned int pol_bits;
+
+	/*
+	 * If the PWM channel is disabled, make sure to turn on the
+	 * clock before calling clk_get_rate() and writing to the
+	 * registers. Otherwise, just keep it enabled.
+	 */
+	if (!pwm_is_enabled(pwm)) {
+		ret = clk_prepare_enable(mxs->clk);
+		if (ret)
+			return ret;
+	}
+
+	if (!state->enabled && pwm_is_enabled(pwm))
+		writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
 
 	rate = clk_get_rate(mxs->clk);
 	while (1) {
-		c = rate / cdiv[div];
-		c = c * period_ns;
+		c = rate >> cdiv_shift[div];
+		c = c * state->period;
 		do_div(c, 1000000000);
 		if (c < PERIOD_PERIOD_MAX)
 			break;
@@ -63,62 +81,40 @@
 	}
 
 	period_cycles = c;
-	c *= duty_ns;
-	do_div(c, period_ns);
+	c *= state->duty_cycle;
+	do_div(c, state->period);
 	duty_cycles = c;
 
 	/*
-	 * If the PWM channel is disabled, make sure to turn on the clock
-	 * before writing the register. Otherwise, keep it enabled.
+	 * The data sheet the says registers must be written to in
+	 * this order (ACTIVEn, then PERIODn). Also, the new settings
+	 * only take effect at the beginning of a new period, avoiding
+	 * glitches.
 	 */
-	if (!pwm_is_enabled(pwm)) {
-		ret = clk_prepare_enable(mxs->clk);
-		if (ret)
-			return ret;
-	}
 
+	pol_bits = state->polarity == PWM_POLARITY_NORMAL ?
+		PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE;
 	writel(duty_cycles << 16,
-			mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
-	writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH |
-	       PERIOD_INACTIVE_LOW | PERIOD_CDIV(div),
-			mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
+	       mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
+	writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div),
+	       mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
 
-	/*
-	 * If the PWM is not enabled, turn the clock off again to save power.
-	 */
-	if (!pwm_is_enabled(pwm))
+	if (state->enabled) {
+		if (!pwm_is_enabled(pwm)) {
+			/*
+			 * The clock was enabled above. Just enable
+			 * the channel in the control register.
+			 */
+			writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
+		}
+	} else {
 		clk_disable_unprepare(mxs->clk);
-
+	}
 	return 0;
 }
 
-static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
-	int ret;
-
-	ret = clk_prepare_enable(mxs->clk);
-	if (ret)
-		return ret;
-
-	writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
-
-	return 0;
-}
-
-static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
-
-	writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
-
-	clk_disable_unprepare(mxs->clk);
-}
-
 static const struct pwm_ops mxs_pwm_ops = {
-	.config = mxs_pwm_config,
-	.enable = mxs_pwm_enable,
-	.disable = mxs_pwm_disable,
+	.apply = mxs_pwm_apply,
 	.owner = THIS_MODULE,
 };
 
@@ -142,6 +138,8 @@
 
 	mxs->chip.dev = &pdev->dev;
 	mxs->chip.ops = &mxs_pwm_ops;
+	mxs->chip.of_xlate = of_pwm_xlate_with_flags;
+	mxs->chip.of_pwm_n_cells = 3;
 	mxs->chip.base = -1;
 
 	ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm);
@@ -150,6 +148,11 @@
 		return ret;
 	}
 
+	/* FIXME: Only do this if the PWM isn't already running */
+	ret = stmp_reset_block(mxs->base);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "failed to reset PWM\n");
+
 	ret = pwmchip_add(&mxs->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
@@ -158,15 +161,7 @@
 
 	platform_set_drvdata(pdev, mxs);
 
-	ret = stmp_reset_block(mxs->base);
-	if (ret)
-		goto pwm_remove;
-
 	return 0;
-
-pwm_remove:
-	pwmchip_remove(&mxs->chip);
-	return ret;
 }
 
 static int mxs_pwm_remove(struct platform_device *pdev)
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 88a3c56..358db4f 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -10,7 +10,27 @@
  *
  * Description:
  *   This file is the core OMAP support for the generic, Linux
- *   PWM driver / controller, using the OMAP's dual-mode timers.
+ *   PWM driver / controller, using the OMAP's dual-mode timers
+ *   with a timer counter that goes up. When it overflows it gets
+ *   reloaded with the load value and the pwm output goes up.
+ *   When counter matches with match register, the output goes down.
+ *   Reference Manual: https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf
+ *
+ * Limitations:
+ * - When PWM is stopped, timer counter gets stopped immediately. This
+ *   doesn't allow the current PWM period to complete and stops abruptly.
+ * - When PWM is running and changing both duty cycle and period,
+ *   we cannot prevent in software that the output might produce
+ *   a period with mixed settings. Especially when period/duty_cyle
+ *   is updated while the pwm pin is high, current pwm period/duty_cycle
+ *   can get updated as below based on the current timer counter:
+ *   	- period for current cycle =  current_period + new period
+ *   	- duty_cycle for current period = current period + new duty_cycle.
+ * - PWM OMAP DM timer cannot change the polarity when pwm is active. When
+ *   user requests a change in polarity when in active state:
+ *	- PWM is stopped abruptly(without completing the current cycle)
+ *	- Polarity is changed
+ *	- A fresh cycle is started.
  */
 
 #include <linux/clk.h>
@@ -20,8 +40,8 @@
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <clocksource/timer-ti-dm.h>
 #include <linux/platform_data/dmtimer-omap.h>
-#include <linux/platform_data/pwm_omap_dmtimer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/pwm.h>
@@ -31,10 +51,20 @@
 #define DM_TIMER_LOAD_MIN 0xfffffffe
 #define DM_TIMER_MAX      0xffffffff
 
+/**
+ * struct pwm_omap_dmtimer_chip - Structure representing a pwm chip
+ *				  corresponding to omap dmtimer.
+ * @chip:		PWM chip structure representing PWM controller
+ * @mutex:		Mutex to protect pwm apply state
+ * @dm_timer:		Pointer to omap dm timer.
+ * @pdata:		Pointer to omap dm timer ops.
+ * @dm_timer_pdev:	Pointer to omap dm timer platform device
+ */
 struct pwm_omap_dmtimer_chip {
 	struct pwm_chip chip;
+	/* Mutex to protect pwm apply state */
 	struct mutex mutex;
-	pwm_omap_dmtimer *dm_timer;
+	struct omap_dm_timer *dm_timer;
 	const struct omap_dm_timer_ops *pdata;
 	struct platform_device *dm_timer_pdev;
 };
@@ -45,11 +75,22 @@
 	return container_of(chip, struct pwm_omap_dmtimer_chip, chip);
 }
 
+/**
+ * pwm_omap_dmtimer_get_clock_cycles() - Get clock cycles in a time frame
+ * @clk_rate:	pwm timer clock rate
+ * @ns:		time frame in nano seconds.
+ *
+ * Return number of clock cycles in a given period(ins ns).
+ */
 static u32 pwm_omap_dmtimer_get_clock_cycles(unsigned long clk_rate, int ns)
 {
 	return DIV_ROUND_CLOSEST_ULL((u64)clk_rate * ns, NSEC_PER_SEC);
 }
 
+/**
+ * pwm_omap_dmtimer_start() - Start the pwm omap dm timer in pwm mode
+ * @omap:	Pointer to pwm omap dm timer chip
+ */
 static void pwm_omap_dmtimer_start(struct pwm_omap_dmtimer_chip *omap)
 {
 	/*
@@ -67,28 +108,46 @@
 	omap->pdata->start(omap->dm_timer);
 }
 
-static int pwm_omap_dmtimer_enable(struct pwm_chip *chip,
-				   struct pwm_device *pwm)
+/**
+ * pwm_omap_dmtimer_is_enabled() -  Detect if the pwm is enabled.
+ * @omap:	Pointer to pwm omap dm timer chip
+ *
+ * Return true if pwm is enabled else false.
+ */
+static bool pwm_omap_dmtimer_is_enabled(struct pwm_omap_dmtimer_chip *omap)
 {
-	struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
+	u32 status;
 
-	mutex_lock(&omap->mutex);
-	pwm_omap_dmtimer_start(omap);
-	mutex_unlock(&omap->mutex);
+	status = omap->pdata->get_pwm_status(omap->dm_timer);
 
-	return 0;
+	return !!(status & OMAP_TIMER_CTRL_ST);
 }
 
-static void pwm_omap_dmtimer_disable(struct pwm_chip *chip,
-				     struct pwm_device *pwm)
+/**
+ * pwm_omap_dmtimer_polarity() -  Detect the polarity of pwm.
+ * @omap:	Pointer to pwm omap dm timer chip
+ *
+ * Return the polarity of pwm.
+ */
+static int pwm_omap_dmtimer_polarity(struct pwm_omap_dmtimer_chip *omap)
 {
-	struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
+	u32 status;
 
-	mutex_lock(&omap->mutex);
-	omap->pdata->stop(omap->dm_timer);
-	mutex_unlock(&omap->mutex);
+	status = omap->pdata->get_pwm_status(omap->dm_timer);
+
+	return !!(status & OMAP_TIMER_CTRL_SCPWM);
 }
 
+/**
+ * pwm_omap_dmtimer_config() - Update the configuration of pwm omap dm timer
+ * @chip:	Pointer to PWM controller
+ * @pwm:	Pointer to PWM channel
+ * @duty_ns:	New duty cycle in nano seconds
+ * @period_ns:	New period in nano seconds
+ *
+ * Return 0 if successfully changed the period/duty_cycle else appropriate
+ * error.
+ */
 static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 				   struct pwm_device *pwm,
 				   int duty_ns, int period_ns)
@@ -96,31 +155,26 @@
 	struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
 	u32 period_cycles, duty_cycles;
 	u32 load_value, match_value;
-	struct clk *fclk;
 	unsigned long clk_rate;
-	bool timer_active;
+	struct clk *fclk;
 
 	dev_dbg(chip->dev, "requested duty cycle: %d ns, period: %d ns\n",
 		duty_ns, period_ns);
 
-	mutex_lock(&omap->mutex);
 	if (duty_ns == pwm_get_duty_cycle(pwm) &&
-	    period_ns == pwm_get_period(pwm)) {
-		/* No change - don't cause any transients. */
-		mutex_unlock(&omap->mutex);
+	    period_ns == pwm_get_period(pwm))
 		return 0;
-	}
 
 	fclk = omap->pdata->get_fclk(omap->dm_timer);
 	if (!fclk) {
 		dev_err(chip->dev, "invalid pmtimer fclk\n");
-		goto err_einval;
+		return -EINVAL;
 	}
 
 	clk_rate = clk_get_rate(fclk);
 	if (!clk_rate) {
 		dev_err(chip->dev, "invalid pmtimer fclk rate\n");
-		goto err_einval;
+		return -EINVAL;
 	}
 
 	dev_dbg(chip->dev, "clk rate: %luHz\n", clk_rate);
@@ -148,7 +202,7 @@
 		dev_info(chip->dev,
 			 "period %d ns too short for clock rate %lu Hz\n",
 			 period_ns, clk_rate);
-		goto err_einval;
+		return -EINVAL;
 	}
 
 	if (duty_cycles < 1) {
@@ -174,79 +228,103 @@
 	load_value = (DM_TIMER_MAX - period_cycles) + 1;
 	match_value = load_value + duty_cycles - 1;
 
-	/*
-	 * We MUST stop the associated dual-mode timer before attempting to
-	 * write its registers, but calls to omap_dm_timer_start/stop must
-	 * be balanced so check if timer is active before calling timer_stop.
-	 */
-	timer_active = pm_runtime_active(&omap->dm_timer_pdev->dev);
-	if (timer_active)
-		omap->pdata->stop(omap->dm_timer);
-
-	omap->pdata->set_load(omap->dm_timer, true, load_value);
+	omap->pdata->set_load(omap->dm_timer, load_value);
 	omap->pdata->set_match(omap->dm_timer, true, match_value);
 
 	dev_dbg(chip->dev, "load value: %#08x (%d), match value: %#08x (%d)\n",
 		load_value, load_value,	match_value, match_value);
 
-	omap->pdata->set_pwm(omap->dm_timer,
-			      pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED,
-			      true,
-			      PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE);
-
-	/* If config was called while timer was running it must be reenabled. */
-	if (timer_active)
-		pwm_omap_dmtimer_start(omap);
-
-	mutex_unlock(&omap->mutex);
-
 	return 0;
-
-err_einval:
-	mutex_unlock(&omap->mutex);
-
-	return -EINVAL;
 }
 
-static int pwm_omap_dmtimer_set_polarity(struct pwm_chip *chip,
-					 struct pwm_device *pwm,
-					 enum pwm_polarity polarity)
+/**
+ * pwm_omap_dmtimer_set_polarity() - Changes the polarity of the pwm dm timer.
+ * @chip:	Pointer to PWM controller
+ * @pwm:	Pointer to PWM channel
+ * @polarity:	New pwm polarity to be set
+ */
+static void pwm_omap_dmtimer_set_polarity(struct pwm_chip *chip,
+					  struct pwm_device *pwm,
+					  enum pwm_polarity polarity)
 {
 	struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
+	bool enabled;
 
-	/*
-	 * PWM core will not call set_polarity while PWM is enabled so it's
-	 * safe to reconfigure the timer here without stopping it first.
-	 */
-	mutex_lock(&omap->mutex);
+	/* Disable the PWM before changing the polarity. */
+	enabled = pwm_omap_dmtimer_is_enabled(omap);
+	if (enabled)
+		omap->pdata->stop(omap->dm_timer);
+
 	omap->pdata->set_pwm(omap->dm_timer,
-			      polarity == PWM_POLARITY_INVERSED,
-			      true,
-			      PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE);
+			     polarity == PWM_POLARITY_INVERSED,
+			     true, OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE,
+			     true);
+
+	if (enabled)
+		pwm_omap_dmtimer_start(omap);
+}
+
+/**
+ * pwm_omap_dmtimer_apply() - Changes the state of the pwm omap dm timer.
+ * @chip:	Pointer to PWM controller
+ * @pwm:	Pointer to PWM channel
+ * @state:	New state to apply
+ *
+ * Return 0 if successfully changed the state else appropriate error.
+ */
+static int pwm_omap_dmtimer_apply(struct pwm_chip *chip,
+				  struct pwm_device *pwm,
+				  const struct pwm_state *state)
+{
+	struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip);
+	int ret = 0;
+
+	mutex_lock(&omap->mutex);
+
+	if (pwm_omap_dmtimer_is_enabled(omap) && !state->enabled) {
+		omap->pdata->stop(omap->dm_timer);
+		goto unlock_mutex;
+	}
+
+	if (pwm_omap_dmtimer_polarity(omap) != state->polarity)
+		pwm_omap_dmtimer_set_polarity(chip, pwm, state->polarity);
+
+	ret = pwm_omap_dmtimer_config(chip, pwm, state->duty_cycle,
+				      state->period);
+	if (ret)
+		goto unlock_mutex;
+
+	if (!pwm_omap_dmtimer_is_enabled(omap) && state->enabled) {
+		omap->pdata->set_pwm(omap->dm_timer,
+				     state->polarity == PWM_POLARITY_INVERSED,
+				     true,
+				     OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE,
+				     true);
+		pwm_omap_dmtimer_start(omap);
+	}
+
+unlock_mutex:
 	mutex_unlock(&omap->mutex);
 
-	return 0;
+	return ret;
 }
 
 static const struct pwm_ops pwm_omap_dmtimer_ops = {
-	.enable	= pwm_omap_dmtimer_enable,
-	.disable = pwm_omap_dmtimer_disable,
-	.config	= pwm_omap_dmtimer_config,
-	.set_polarity = pwm_omap_dmtimer_set_polarity,
+	.apply = pwm_omap_dmtimer_apply,
 	.owner = THIS_MODULE,
 };
 
 static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	struct device_node *timer;
-	struct platform_device *timer_pdev;
-	struct pwm_omap_dmtimer_chip *omap;
 	struct dmtimer_platform_data *timer_pdata;
 	const struct omap_dm_timer_ops *pdata;
-	pwm_omap_dmtimer *dm_timer;
-	u32 v;
+	struct platform_device *timer_pdev;
+	struct pwm_omap_dmtimer_chip *omap;
+	struct omap_dm_timer *dm_timer;
+	struct device_node *timer;
 	int ret = 0;
+	u32 v;
 
 	timer = of_parse_phandle(np, "ti,timers", 0);
 	if (!timer)
@@ -279,6 +357,7 @@
 	    !pdata->set_load ||
 	    !pdata->set_match ||
 	    !pdata->set_pwm ||
+	    !pdata->get_pwm_status ||
 	    !pdata->set_prescaler ||
 	    !pdata->write_counter) {
 		dev_err(&pdev->dev, "Incomplete dmtimer pdata structure\n");
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 590375b..4a55dc1 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -57,10 +57,14 @@
 #define PCA9685_NUMREGS		0xFF
 #define PCA9685_MAXCHAN		0x10
 
-#define LED_FULL		(1 << 4)
-#define MODE1_SLEEP		(1 << 4)
-#define MODE2_INVRT		(1 << 4)
-#define MODE2_OUTDRV		(1 << 2)
+#define LED_FULL		BIT(4)
+#define MODE1_ALLCALL		BIT(0)
+#define MODE1_SUB3		BIT(1)
+#define MODE1_SUB2		BIT(2)
+#define MODE1_SUB1		BIT(3)
+#define MODE1_SLEEP		BIT(4)
+#define MODE2_INVRT		BIT(4)
+#define MODE2_OUTDRV		BIT(2)
 
 #define LED_N_ON_H(N)	(PCA9685_LEDX_ON_H + (4 * (N)))
 #define LED_N_ON_L(N)	(PCA9685_LEDX_ON_L + (4 * (N)))
@@ -70,7 +74,6 @@
 struct pca9685 {
 	struct pwm_chip chip;
 	struct regmap *regmap;
-	int duty_ns;
 	int period_ns;
 #if IS_ENABLED(CONFIG_GPIOLIB)
 	struct mutex lock;
@@ -92,7 +95,7 @@
 	mutex_lock(&pca->lock);
 	if (pwm_idx >= PCA9685_MAXCHAN) {
 		/*
-		 * "all LEDs" channel:
+		 * "All LEDs" channel:
 		 * pretend already in use if any of the PWMs are requested
 		 */
 		if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
@@ -101,7 +104,7 @@
 		}
 	} else {
 		/*
-		 * regular channel:
+		 * Regular channel:
 		 * pretend already in use if the "all LEDs" channel is requested
 		 */
 		if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
@@ -171,7 +174,7 @@
 					  unsigned int offset)
 {
 	/* Always out */
-	return 0;
+	return GPIO_LINE_DIRECTION_OUT;
 }
 
 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
@@ -258,7 +261,7 @@
 		if (prescale >= PCA9685_PRESCALE_MIN &&
 			prescale <= PCA9685_PRESCALE_MAX) {
 			/*
-			 * putting the chip briefly into SLEEP mode
+			 * Putting the chip briefly into SLEEP mode
 			 * at this point won't interfere with the
 			 * pm_runtime framework, because the pm_runtime
 			 * state is guaranteed active here.
@@ -280,8 +283,6 @@
 		}
 	}
 
-	pca->duty_ns = duty_ns;
-
 	if (duty_ns < 1) {
 		if (pwm->hwpwm >= PCA9685_MAXCHAN)
 			reg = PCA9685_ALL_LED_OFF_H;
@@ -446,8 +447,8 @@
 				const struct i2c_device_id *id)
 {
 	struct pca9685 *pca;
+	unsigned int reg;
 	int ret;
-	int mode2;
 
 	pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL);
 	if (!pca)
@@ -460,31 +461,35 @@
 			ret);
 		return ret;
 	}
-	pca->duty_ns = 0;
 	pca->period_ns = PCA9685_DEFAULT_PERIOD;
 
 	i2c_set_clientdata(client, pca);
 
-	regmap_read(pca->regmap, PCA9685_MODE2, &mode2);
+	regmap_read(pca->regmap, PCA9685_MODE2, &reg);
 
 	if (device_property_read_bool(&client->dev, "invert"))
-		mode2 |= MODE2_INVRT;
+		reg |= MODE2_INVRT;
 	else
-		mode2 &= ~MODE2_INVRT;
+		reg &= ~MODE2_INVRT;
 
 	if (device_property_read_bool(&client->dev, "open-drain"))
-		mode2 &= ~MODE2_OUTDRV;
+		reg &= ~MODE2_OUTDRV;
 	else
-		mode2 |= MODE2_OUTDRV;
+		reg |= MODE2_OUTDRV;
 
-	regmap_write(pca->regmap, PCA9685_MODE2, mode2);
+	regmap_write(pca->regmap, PCA9685_MODE2, reg);
 
-	/* clear all "full off" bits */
+	/* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */
+	regmap_read(pca->regmap, PCA9685_MODE1, &reg);
+	reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3);
+	regmap_write(pca->regmap, PCA9685_MODE1, reg);
+
+	/* Clear all "full off" bits */
 	regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
 	regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
 
 	pca->chip.ops = &pca9685_pwm_ops;
-	/* add an extra channel for ALL_LED */
+	/* Add an extra channel for ALL_LED */
 	pca->chip.npwm = PCA9685_MAXCHAN + 1;
 
 	pca->chip.dev = &client->dev;
@@ -500,10 +505,10 @@
 		return ret;
 	}
 
-	/* the chip comes out of power-up in the active state */
+	/* The chip comes out of power-up in the active state */
 	pm_runtime_set_active(&client->dev);
 	/*
-	 * enable will put the chip into suspend, which is what we
+	 * Enable will put the chip into suspend, which is what we
 	 * want as all outputs are disabled at this point
 	 */
 	pm_runtime_enable(&client->dev);
@@ -523,8 +528,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_PM
-static int pca9685_pwm_runtime_suspend(struct device *dev)
+static int __maybe_unused pca9685_pwm_runtime_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct pca9685 *pca = i2c_get_clientdata(client);
@@ -533,7 +537,7 @@
 	return 0;
 }
 
-static int pca9685_pwm_runtime_resume(struct device *dev)
+static int __maybe_unused pca9685_pwm_runtime_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct pca9685 *pca = i2c_get_clientdata(client);
@@ -541,7 +545,6 @@
 	pca9685_set_sleep_mode(pca, false);
 	return 0;
 }
-#endif
 
 static const struct i2c_device_id pca9685_id[] = {
 	{ "pca9685", 0 },
diff --git a/drivers/pwm/pwm-puv3.c b/drivers/pwm/pwm-puv3.c
deleted file mode 100644
index 9d0bd87..0000000
--- a/drivers/pwm/pwm-puv3.c
+++ /dev/null
@@ -1,150 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * linux/arch/unicore32/kernel/pwm.c
- *
- * Code specific to PKUnity SoC and UniCore ISA
- *
- *	Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
- *	Copyright (C) 2001-2010 Guan Xuetao
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/pwm.h>
-
-#include <asm/div64.h>
-#include <mach/hardware.h>
-
-struct puv3_pwm_chip {
-	struct pwm_chip chip;
-	void __iomem *base;
-	struct clk *clk;
-};
-
-static inline struct puv3_pwm_chip *to_puv3(struct pwm_chip *chip)
-{
-	return container_of(chip, struct puv3_pwm_chip, chip);
-}
-
-/*
- * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
- * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
- */
-static int puv3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
-			   int duty_ns, int period_ns)
-{
-	unsigned long period_cycles, prescale, pv, dc;
-	struct puv3_pwm_chip *puv3 = to_puv3(chip);
-	unsigned long long c;
-
-	c = clk_get_rate(puv3->clk);
-	c = c * period_ns;
-	do_div(c, 1000000000);
-	period_cycles = c;
-
-	if (period_cycles < 1)
-		period_cycles = 1;
-
-	prescale = (period_cycles - 1) / 1024;
-	pv = period_cycles / (prescale + 1) - 1;
-
-	if (prescale > 63)
-		return -EINVAL;
-
-	if (duty_ns == period_ns)
-		dc = OST_PWMDCCR_FDCYCLE;
-	else
-		dc = (pv + 1) * duty_ns / period_ns;
-
-	/*
-	 * NOTE: the clock to PWM has to be enabled first
-	 * before writing to the registers
-	 */
-	clk_prepare_enable(puv3->clk);
-
-	writel(prescale, puv3->base + OST_PWM_PWCR);
-	writel(pv - dc, puv3->base + OST_PWM_DCCR);
-	writel(pv, puv3->base + OST_PWM_PCR);
-
-	clk_disable_unprepare(puv3->clk);
-
-	return 0;
-}
-
-static int puv3_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct puv3_pwm_chip *puv3 = to_puv3(chip);
-
-	return clk_prepare_enable(puv3->clk);
-}
-
-static void puv3_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct puv3_pwm_chip *puv3 = to_puv3(chip);
-
-	clk_disable_unprepare(puv3->clk);
-}
-
-static const struct pwm_ops puv3_pwm_ops = {
-	.config = puv3_pwm_config,
-	.enable = puv3_pwm_enable,
-	.disable = puv3_pwm_disable,
-	.owner = THIS_MODULE,
-};
-
-static int pwm_probe(struct platform_device *pdev)
-{
-	struct puv3_pwm_chip *puv3;
-	struct resource *r;
-	int ret;
-
-	puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
-	if (!puv3)
-		return -ENOMEM;
-
-	puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
-	if (IS_ERR(puv3->clk))
-		return PTR_ERR(puv3->clk);
-
-	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	puv3->base = devm_ioremap_resource(&pdev->dev, r);
-	if (IS_ERR(puv3->base))
-		return PTR_ERR(puv3->base);
-
-	puv3->chip.dev = &pdev->dev;
-	puv3->chip.ops = &puv3_pwm_ops;
-	puv3->chip.base = -1;
-	puv3->chip.npwm = 1;
-
-	ret = pwmchip_add(&puv3->chip);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
-		return ret;
-	}
-
-	platform_set_drvdata(pdev, puv3);
-	return 0;
-}
-
-static int pwm_remove(struct platform_device *pdev)
-{
-	struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&puv3->chip);
-}
-
-static struct platform_driver puv3_pwm_driver = {
-	.driver = {
-		.name = "PKUnity-v3-PWM",
-	},
-	.probe = pwm_probe,
-	.remove = pwm_remove,
-};
-module_platform_driver(puv3_pwm_driver);
-
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index b98ec88..7ab9eb6 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -3,6 +3,9 @@
  * R-Car PWM Timer driver
  *
  * Copyright (C) 2015 Renesas Electronics Corporation
+ *
+ * Limitations:
+ * - The hardware cannot generate a 0% duty cycle.
  */
 
 #include <linux/clk.h>
@@ -161,11 +164,9 @@
 			  const struct pwm_state *state)
 {
 	struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
-	struct pwm_state cur_state;
 	int div, ret;
 
 	/* This HW/driver only supports normal polarity */
-	pwm_get_state(pwm, &cur_state);
 	if (state->polarity != PWM_POLARITY_NORMAL)
 		return -ENOTSUPP;
 
diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c
index 8032acc..81ad5a5 100644
--- a/drivers/pwm/pwm-renesas-tpu.c
+++ b/drivers/pwm/pwm-renesas-tpu.c
@@ -424,8 +424,6 @@
 		return ret;
 	}
 
-	dev_info(&pdev->dev, "TPU PWM %d registered\n", tpu->pdev->id);
-
 	return 0;
 }
 
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 6ad6aad..1f30795 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -83,12 +83,7 @@
 	state->duty_cycle =  DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
 
 	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
-	if (pc->data->supports_polarity)
-		state->enabled = ((val & enable_conf) != enable_conf) ?
-				 false : true;
-	else
-		state->enabled = ((val & enable_conf) == enable_conf) ?
-				 true : false;
+	state->enabled = (val & enable_conf) == enable_conf;
 
 	if (pc->data->supports_polarity && !(val & PWM_DUTY_POSITIVE))
 		state->polarity = PWM_POLARITY_INVERSED;
@@ -293,6 +288,8 @@
 	const struct of_device_id *id;
 	struct rockchip_pwm_chip *pc;
 	struct resource *r;
+	u32 enable_conf, ctrl;
+	bool enabled;
 	int ret, count;
 
 	id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
@@ -311,13 +308,9 @@
 	pc->clk = devm_clk_get(&pdev->dev, "pwm");
 	if (IS_ERR(pc->clk)) {
 		pc->clk = devm_clk_get(&pdev->dev, NULL);
-		if (IS_ERR(pc->clk)) {
-			ret = PTR_ERR(pc->clk);
-			if (ret != -EPROBE_DEFER)
-				dev_err(&pdev->dev, "Can't get bus clk: %d\n",
-					ret);
-			return ret;
-		}
+		if (IS_ERR(pc->clk))
+			return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+					     "Can't get bus clk\n");
 	}
 
 	count = of_count_phandle_with_args(pdev->dev.of_node,
@@ -340,9 +333,9 @@
 		return ret;
 	}
 
-	ret = clk_prepare(pc->pclk);
+	ret = clk_prepare_enable(pc->pclk);
 	if (ret) {
-		dev_err(&pdev->dev, "Can't prepare APB clk: %d\n", ret);
+		dev_err(&pdev->dev, "Can't prepare enable APB clk: %d\n", ret);
 		goto err_clk;
 	}
 
@@ -359,6 +352,10 @@
 		pc->chip.of_pwm_n_cells = 3;
 	}
 
+	enable_conf = pc->data->enable_conf;
+	ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
+	enabled = (ctrl & enable_conf) == enable_conf;
+
 	ret = pwmchip_add(&pc->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
@@ -366,13 +363,15 @@
 	}
 
 	/* Keep the PWM clk enabled if the PWM appears to be up and running. */
-	if (!pwm_is_enabled(pc->chip.pwms))
+	if (!enabled)
 		clk_disable(pc->clk);
 
+	clk_disable(pc->pclk);
+
 	return 0;
 
 err_pclk:
-	clk_unprepare(pc->pclk);
+	clk_disable_unprepare(pc->pclk);
 err_clk:
 	clk_disable_unprepare(pc->clk);
 
@@ -383,20 +382,6 @@
 {
 	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
 
-	/*
-	 * Disable the PWM clk before unpreparing it if the PWM device is still
-	 * running. This should only happen when the last PWM user left it
-	 * enabled, or when nobody requested a PWM that was previously enabled
-	 * by the bootloader.
-	 *
-	 * FIXME: Maybe the core should disable all PWM devices in
-	 * pwmchip_remove(). In this case we'd only have to call
-	 * clk_unprepare() after pwmchip_remove().
-	 *
-	 */
-	if (pwm_is_enabled(pc->chip.pwms))
-		clk_disable(pc->clk);
-
 	clk_unprepare(pc->pclk);
 	clk_unprepare(pc->clk);
 
diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
index cc63f9b..2485fba 100644
--- a/drivers/pwm/pwm-sifive.c
+++ b/drivers/pwm/pwm-sifive.c
@@ -181,7 +181,7 @@
 	 * consecutively
 	 */
 	num = (u64)duty_cycle * (1U << PWM_SIFIVE_CMPWIDTH);
-	frac = DIV_ROUND_CLOSEST_ULL(num, state->period);
+	frac = DIV64_U64_ROUND_CLOSEST(num, state->period);
 	/* The hardware cannot generate a 100% duty cycle */
 	frac = min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1);
 
@@ -254,11 +254,9 @@
 		return PTR_ERR(ddata->regs);
 
 	ddata->clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(ddata->clk)) {
-		if (PTR_ERR(ddata->clk) != -EPROBE_DEFER)
-			dev_err(dev, "Unable to find controller clock\n");
-		return PTR_ERR(ddata->clk);
-	}
+	if (IS_ERR(ddata->clk))
+		return dev_err_probe(dev, PTR_ERR(ddata->clk),
+				     "Unable to find controller clock\n");
 
 	ret = clk_prepare_enable(ddata->clk);
 	if (ret) {
diff --git a/drivers/pwm/pwm-sl28cpld.c b/drivers/pwm/pwm-sl28cpld.c
new file mode 100644
index 0000000..b4c651f
--- /dev/null
+++ b/drivers/pwm/pwm-sl28cpld.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sl28cpld PWM driver
+ *
+ * Copyright (c) 2020 Michael Walle <michael@walle.cc>
+ *
+ * There is no public datasheet available for this PWM core. But it is easy
+ * enough to be briefly explained. It consists of one 8-bit counter. The PWM
+ * supports four distinct frequencies by selecting when to reset the counter.
+ * With the prescaler setting you can select which bit of the counter is used
+ * to reset it. This implies that the higher the frequency the less remaining
+ * bits are available for the actual counter.
+ *
+ * Let cnt[7:0] be the counter, clocked at 32kHz:
+ * +-----------+--------+--------------+-----------+---------------+
+ * | prescaler |  reset | counter bits | frequency | period length |
+ * +-----------+--------+--------------+-----------+---------------+
+ * |         0 | cnt[7] |     cnt[6:0] |    250 Hz |    4000000 ns |
+ * |         1 | cnt[6] |     cnt[5:0] |    500 Hz |    2000000 ns |
+ * |         2 | cnt[5] |     cnt[4:0] |     1 kHz |    1000000 ns |
+ * |         3 | cnt[4] |     cnt[3:0] |     2 kHz |     500000 ns |
+ * +-----------+--------+--------------+-----------+---------------+
+ *
+ * Limitations:
+ * - The hardware cannot generate a 100% duty cycle if the prescaler is 0.
+ * - The hardware cannot atomically set the prescaler and the counter value,
+ *   which might lead to glitches and inconsistent states if a write fails.
+ * - The counter is not reset if you switch the prescaler which leads
+ *   to glitches, too.
+ * - The duty cycle will switch immediately and not after a complete cycle.
+ * - Depending on the actual implementation, disabling the PWM might have
+ *   side effects. For example, if the output pin is shared with a GPIO pin
+ *   it will automatically switch back to GPIO mode.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+/*
+ * PWM timer block registers.
+ */
+#define SL28CPLD_PWM_CTRL			0x00
+#define   SL28CPLD_PWM_CTRL_ENABLE		BIT(7)
+#define   SL28CPLD_PWM_CTRL_PRESCALER_MASK	GENMASK(1, 0)
+#define SL28CPLD_PWM_CYCLE			0x01
+#define   SL28CPLD_PWM_CYCLE_MAX		GENMASK(6, 0)
+
+#define SL28CPLD_PWM_CLK			32000 /* 32 kHz */
+#define SL28CPLD_PWM_MAX_DUTY_CYCLE(prescaler)	(1 << (7 - (prescaler)))
+#define SL28CPLD_PWM_PERIOD(prescaler) \
+	(NSEC_PER_SEC / SL28CPLD_PWM_CLK * SL28CPLD_PWM_MAX_DUTY_CYCLE(prescaler))
+
+/*
+ * We calculate the duty cycle like this:
+ *   duty_cycle_ns = pwm_cycle_reg * max_period_ns / max_duty_cycle
+ *
+ * With
+ *   max_period_ns = 1 << (7 - prescaler) / SL28CPLD_PWM_CLK * NSEC_PER_SEC
+ *   max_duty_cycle = 1 << (7 - prescaler)
+ * this then simplifies to:
+ *   duty_cycle_ns = pwm_cycle_reg / SL28CPLD_PWM_CLK * NSEC_PER_SEC
+ *                 = NSEC_PER_SEC / SL28CPLD_PWM_CLK * pwm_cycle_reg
+ *
+ * NSEC_PER_SEC is a multiple of SL28CPLD_PWM_CLK, therefore we're not losing
+ * precision by doing the divison first.
+ */
+#define SL28CPLD_PWM_TO_DUTY_CYCLE(reg) \
+	(NSEC_PER_SEC / SL28CPLD_PWM_CLK * (reg))
+#define SL28CPLD_PWM_FROM_DUTY_CYCLE(duty_cycle) \
+	(DIV_ROUND_DOWN_ULL((duty_cycle), NSEC_PER_SEC / SL28CPLD_PWM_CLK))
+
+#define sl28cpld_pwm_read(priv, reg, val) \
+	regmap_read((priv)->regmap, (priv)->offset + (reg), (val))
+#define sl28cpld_pwm_write(priv, reg, val) \
+	regmap_write((priv)->regmap, (priv)->offset + (reg), (val))
+
+struct sl28cpld_pwm {
+	struct pwm_chip pwm_chip;
+	struct regmap *regmap;
+	u32 offset;
+};
+#define sl28cpld_pwm_from_chip(_chip) \
+	container_of(_chip, struct sl28cpld_pwm, pwm_chip)
+
+static void sl28cpld_pwm_get_state(struct pwm_chip *chip,
+				   struct pwm_device *pwm,
+				   struct pwm_state *state)
+{
+	struct sl28cpld_pwm *priv = sl28cpld_pwm_from_chip(chip);
+	unsigned int reg;
+	int prescaler;
+
+	sl28cpld_pwm_read(priv, SL28CPLD_PWM_CTRL, &reg);
+
+	state->enabled = reg & SL28CPLD_PWM_CTRL_ENABLE;
+
+	prescaler = FIELD_GET(SL28CPLD_PWM_CTRL_PRESCALER_MASK, reg);
+	state->period = SL28CPLD_PWM_PERIOD(prescaler);
+
+	sl28cpld_pwm_read(priv, SL28CPLD_PWM_CYCLE, &reg);
+	state->duty_cycle = SL28CPLD_PWM_TO_DUTY_CYCLE(reg);
+	state->polarity = PWM_POLARITY_NORMAL;
+
+	/*
+	 * Sanitize values for the PWM core. Depending on the prescaler it
+	 * might happen that we calculate a duty_cycle greater than the actual
+	 * period. This might happen if someone (e.g. the bootloader) sets an
+	 * invalid combination of values. The behavior of the hardware is
+	 * undefined in this case. But we need to report sane values back to
+	 * the PWM core.
+	 */
+	state->duty_cycle = min(state->duty_cycle, state->period);
+}
+
+static int sl28cpld_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
+{
+	struct sl28cpld_pwm *priv = sl28cpld_pwm_from_chip(chip);
+	unsigned int cycle, prescaler;
+	bool write_duty_cycle_first;
+	int ret;
+	u8 ctrl;
+
+	/* Polarity inversion is not supported */
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	/*
+	 * Calculate the prescaler. Pick the biggest period that isn't
+	 * bigger than the requested period.
+	 */
+	prescaler = DIV_ROUND_UP_ULL(SL28CPLD_PWM_PERIOD(0), state->period);
+	prescaler = order_base_2(prescaler);
+
+	if (prescaler > field_max(SL28CPLD_PWM_CTRL_PRESCALER_MASK))
+		return -ERANGE;
+
+	ctrl = FIELD_PREP(SL28CPLD_PWM_CTRL_PRESCALER_MASK, prescaler);
+	if (state->enabled)
+		ctrl |= SL28CPLD_PWM_CTRL_ENABLE;
+
+	cycle = SL28CPLD_PWM_FROM_DUTY_CYCLE(state->duty_cycle);
+	cycle = min_t(unsigned int, cycle, SL28CPLD_PWM_MAX_DUTY_CYCLE(prescaler));
+
+	/*
+	 * Work around the hardware limitation. See also above. Trap 100% duty
+	 * cycle if the prescaler is 0. Set prescaler to 1 instead. We don't
+	 * care about the frequency because its "all-one" in either case.
+	 *
+	 * We don't need to check the actual prescaler setting, because only
+	 * if the prescaler is 0 we can have this particular value.
+	 */
+	if (cycle == SL28CPLD_PWM_MAX_DUTY_CYCLE(0)) {
+		ctrl &= ~SL28CPLD_PWM_CTRL_PRESCALER_MASK;
+		ctrl |= FIELD_PREP(SL28CPLD_PWM_CTRL_PRESCALER_MASK, 1);
+		cycle = SL28CPLD_PWM_MAX_DUTY_CYCLE(1);
+	}
+
+	/*
+	 * To avoid glitches when we switch the prescaler, we have to make sure
+	 * we have a valid duty cycle for the new mode.
+	 *
+	 * Take the current prescaler (or the current period length) into
+	 * account to decide whether we have to write the duty cycle or the new
+	 * prescaler first. If the period length is decreasing we have to
+	 * write the duty cycle first.
+	 */
+	write_duty_cycle_first = pwm->state.period > state->period;
+
+	if (write_duty_cycle_first) {
+		ret = sl28cpld_pwm_write(priv, SL28CPLD_PWM_CYCLE, cycle);
+		if (ret)
+			return ret;
+	}
+
+	ret = sl28cpld_pwm_write(priv, SL28CPLD_PWM_CTRL, ctrl);
+	if (ret)
+		return ret;
+
+	if (!write_duty_cycle_first) {
+		ret = sl28cpld_pwm_write(priv, SL28CPLD_PWM_CYCLE, cycle);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct pwm_ops sl28cpld_pwm_ops = {
+	.apply = sl28cpld_pwm_apply,
+	.get_state = sl28cpld_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static int sl28cpld_pwm_probe(struct platform_device *pdev)
+{
+	struct sl28cpld_pwm *priv;
+	struct pwm_chip *chip;
+	int ret;
+
+	if (!pdev->dev.parent) {
+		dev_err(&pdev->dev, "no parent device\n");
+		return -ENODEV;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!priv->regmap) {
+		dev_err(&pdev->dev, "could not get parent regmap\n");
+		return -ENODEV;
+	}
+
+	ret = device_property_read_u32(&pdev->dev, "reg", &priv->offset);
+	if (ret) {
+		dev_err(&pdev->dev, "no 'reg' property found (%pe)\n",
+			ERR_PTR(ret));
+		return -EINVAL;
+	}
+
+	/* Initialize the pwm_chip structure */
+	chip = &priv->pwm_chip;
+	chip->dev = &pdev->dev;
+	chip->ops = &sl28cpld_pwm_ops;
+	chip->base = -1;
+	chip->npwm = 1;
+
+	ret = pwmchip_add(&priv->pwm_chip);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add PWM chip (%pe)",
+			ERR_PTR(ret));
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int sl28cpld_pwm_remove(struct platform_device *pdev)
+{
+	struct sl28cpld_pwm *priv = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&priv->pwm_chip);
+}
+
+static const struct of_device_id sl28cpld_pwm_of_match[] = {
+	{ .compatible = "kontron,sl28cpld-pwm" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sl28cpld_pwm_of_match);
+
+static struct platform_driver sl28cpld_pwm_driver = {
+	.probe = sl28cpld_pwm_probe,
+	.remove	= sl28cpld_pwm_remove,
+	.driver = {
+		.name = "sl28cpld-pwm",
+		.of_match_table = sl28cpld_pwm_of_match,
+	},
+};
+module_platform_driver(sl28cpld_pwm_driver);
+
+MODULE_DESCRIPTION("sl28cpld PWM Driver");
+MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pwm/pwm-sprd.c b/drivers/pwm/pwm-sprd.c
index 892d853..9eeb59c 100644
--- a/drivers/pwm/pwm-sprd.c
+++ b/drivers/pwm/pwm-sprd.c
@@ -225,11 +225,8 @@
 			if (ret == -ENOENT)
 				break;
 
-			if (ret != -EPROBE_DEFER)
-				dev_err(spc->dev,
-					"failed to get channel clocks\n");
-
-			return ret;
+			return dev_err_probe(spc->dev, ret,
+					     "failed to get channel clocks\n");
 		}
 
 		clk_pwm = chn->clks[SPRD_PWM_CHN_OUTPUT_CLK].clk;
diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 67fca62..945a8b2 100644
--- a/drivers/pwm/pwm-stm32-lp.c
+++ b/drivers/pwm/pwm-stm32-lp.c
@@ -61,7 +61,7 @@
 	do_div(div, NSEC_PER_SEC);
 	if (!div) {
 		/* Clock is too slow to achieve requested period. */
-		dev_dbg(priv->chip.dev, "Can't reach %u ns\n",	state->period);
+		dev_dbg(priv->chip.dev, "Can't reach %llu ns\n", state->period);
 		return -EINVAL;
 	}
 
@@ -225,8 +225,6 @@
 {
 	struct stm32_pwm_lp *priv = platform_get_drvdata(pdev);
 
-	pwm_disable(&priv->chip.pwms[0]);
-
 	return pwmchip_remove(&priv->chip);
 }
 
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index 359b085..d3be944 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -12,6 +12,7 @@
 #include <linux/mfd/stm32-timers.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 
@@ -19,6 +20,12 @@
 #define CCMR_CHANNEL_MASK  0xFF
 #define MAX_BREAKINPUT 2
 
+struct stm32_breakinput {
+	u32 index;
+	u32 level;
+	u32 filter;
+};
+
 struct stm32_pwm {
 	struct pwm_chip chip;
 	struct mutex lock; /* protect pwm config/enable */
@@ -26,15 +33,11 @@
 	struct regmap *regmap;
 	u32 max_arr;
 	bool have_complementary_output;
+	struct stm32_breakinput breakinputs[MAX_BREAKINPUT];
+	unsigned int num_breakinputs;
 	u32 capture[4] ____cacheline_aligned; /* DMA'able buffer */
 };
 
-struct stm32_breakinput {
-	u32 index;
-	u32 level;
-	u32 filter;
-};
-
 static inline struct stm32_pwm *to_stm32_pwm_dev(struct pwm_chip *chip)
 {
 	return container_of(chip, struct stm32_pwm, chip);
@@ -374,9 +377,7 @@
 	else
 		regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
 
-	regmap_update_bits(priv->regmap, TIM_BDTR,
-			   TIM_BDTR_MOE | TIM_BDTR_AOE,
-			   TIM_BDTR_MOE | TIM_BDTR_AOE);
+	regmap_update_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE, TIM_BDTR_MOE);
 
 	return 0;
 }
@@ -488,22 +489,19 @@
 };
 
 static int stm32_pwm_set_breakinput(struct stm32_pwm *priv,
-				    int index, int level, int filter)
+				    const struct stm32_breakinput *bi)
 {
-	u32 bke = (index == 0) ? TIM_BDTR_BKE : TIM_BDTR_BK2E;
-	int shift = (index == 0) ? TIM_BDTR_BKF_SHIFT : TIM_BDTR_BK2F_SHIFT;
-	u32 mask = (index == 0) ? TIM_BDTR_BKE | TIM_BDTR_BKP | TIM_BDTR_BKF
-				: TIM_BDTR_BK2E | TIM_BDTR_BK2P | TIM_BDTR_BK2F;
-	u32 bdtr = bke;
+	u32 shift = TIM_BDTR_BKF_SHIFT(bi->index);
+	u32 bke = TIM_BDTR_BKE(bi->index);
+	u32 bkp = TIM_BDTR_BKP(bi->index);
+	u32 bkf = TIM_BDTR_BKF(bi->index);
+	u32 mask = bkf | bkp | bke;
+	u32 bdtr;
 
-	/*
-	 * The both bits could be set since only one will be wrote
-	 * due to mask value.
-	 */
-	if (level)
-		bdtr |= TIM_BDTR_BKP | TIM_BDTR_BK2P;
+	bdtr = (bi->filter & TIM_BDTR_BKF_MASK) << shift | bke;
 
-	bdtr |= (filter & TIM_BDTR_BKF_MASK) << shift;
+	if (bi->level)
+		bdtr |= bkp;
 
 	regmap_update_bits(priv->regmap, TIM_BDTR, mask, bdtr);
 
@@ -512,11 +510,25 @@
 	return (bdtr & bke) ? 0 : -EINVAL;
 }
 
-static int stm32_pwm_apply_breakinputs(struct stm32_pwm *priv,
+static int stm32_pwm_apply_breakinputs(struct stm32_pwm *priv)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < priv->num_breakinputs; i++) {
+		ret = stm32_pwm_set_breakinput(priv, &priv->breakinputs[i]);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_pwm_probe_breakinputs(struct stm32_pwm *priv,
 				       struct device_node *np)
 {
-	struct stm32_breakinput breakinput[MAX_BREAKINPUT];
-	int nb, ret, i, array_size;
+	int nb, ret, array_size;
+	unsigned int i;
 
 	nb = of_property_count_elems_of_size(np, "st,breakinput",
 					     sizeof(struct stm32_breakinput));
@@ -531,20 +543,21 @@
 	if (nb > MAX_BREAKINPUT)
 		return -EINVAL;
 
+	priv->num_breakinputs = nb;
 	array_size = nb * sizeof(struct stm32_breakinput) / sizeof(u32);
 	ret = of_property_read_u32_array(np, "st,breakinput",
-					 (u32 *)breakinput, array_size);
+					 (u32 *)priv->breakinputs, array_size);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < nb && !ret; i++) {
-		ret = stm32_pwm_set_breakinput(priv,
-					       breakinput[i].index,
-					       breakinput[i].level,
-					       breakinput[i].filter);
+	for (i = 0; i < priv->num_breakinputs; i++) {
+		if (priv->breakinputs[i].index > 1 ||
+		    priv->breakinputs[i].level > 1 ||
+		    priv->breakinputs[i].filter > 15)
+			return -EINVAL;
 	}
 
-	return ret;
+	return stm32_pwm_apply_breakinputs(priv);
 }
 
 static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
@@ -614,7 +627,7 @@
 	if (!priv->regmap || !priv->clk)
 		return -EINVAL;
 
-	ret = stm32_pwm_apply_breakinputs(priv, np);
+	ret = stm32_pwm_probe_breakinputs(priv, np);
 	if (ret)
 		return ret;
 
@@ -647,6 +660,42 @@
 	return 0;
 }
 
+static int __maybe_unused stm32_pwm_suspend(struct device *dev)
+{
+	struct stm32_pwm *priv = dev_get_drvdata(dev);
+	unsigned int i;
+	u32 ccer, mask;
+
+	/* Look for active channels */
+	ccer = active_channels(priv);
+
+	for (i = 0; i < priv->chip.npwm; i++) {
+		mask = TIM_CCER_CC1E << (i * 4);
+		if (ccer & mask) {
+			dev_err(dev, "PWM %u still in use by consumer %s\n",
+				i, priv->chip.pwms[i].label);
+			return -EBUSY;
+		}
+	}
+
+	return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int __maybe_unused stm32_pwm_resume(struct device *dev)
+{
+	struct stm32_pwm *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret)
+		return ret;
+
+	/* restore breakinput registers that may have been lost in low power */
+	return stm32_pwm_apply_breakinputs(priv);
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_pwm_pm_ops, stm32_pwm_suspend, stm32_pwm_resume);
+
 static const struct of_device_id stm32_pwm_of_match[] = {
 	{ .compatible = "st,stm32-pwm",	},
 	{ /* end node */ },
@@ -659,6 +708,7 @@
 	.driver	= {
 		.name = "stm32-pwm",
 		.of_match_table = stm32_pwm_of_match,
+		.pm = &stm32_pwm_pm_ops,
 	},
 };
 module_platform_driver(stm32_pwm_driver);
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 0527372..482d5b9 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -3,6 +3,10 @@
  * Driver for Allwinner sun4i Pulse Width Modulation Controller
  *
  * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ *
+ * Limitations:
+ * - When outputing the source clock directly, the PWM logic will be bypassed
+ *   and the currently running period is not guaranteed to be completed
  */
 
 #include <linux/bitops.h>
@@ -16,6 +20,7 @@
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/time.h>
@@ -72,17 +77,19 @@
 
 struct sun4i_pwm_data {
 	bool has_prescaler_bypass;
+	bool has_direct_mod_clk_output;
 	unsigned int npwm;
 };
 
 struct sun4i_pwm_chip {
 	struct pwm_chip chip;
+	struct clk *bus_clk;
 	struct clk *clk;
+	struct reset_control *rst;
 	void __iomem *base;
 	spinlock_t ctrl_lock;
 	const struct sun4i_pwm_data *data;
 	unsigned long next_period[2];
-	bool needs_delay[2];
 };
 
 static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
@@ -115,6 +122,20 @@
 
 	val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 
+	/*
+	 * PWM chapter in H6 manual has a diagram which explains that if bypass
+	 * bit is set, no other setting has any meaning. Even more, experiment
+	 * proved that also enable bit is ignored in this case.
+	 */
+	if ((val & BIT_CH(PWM_BYPASS, pwm->hwpwm)) &&
+	    sun4i_pwm->data->has_direct_mod_clk_output) {
+		state->period = DIV_ROUND_UP_ULL(NSEC_PER_SEC, clk_rate);
+		state->duty_cycle = DIV_ROUND_UP_ULL(state->period, 2);
+		state->polarity = PWM_POLARITY_NORMAL;
+		state->enabled = true;
+		return;
+	}
+
 	if ((PWM_REG_PRESCAL(val, pwm->hwpwm) == PWM_PRESCAL_MASK) &&
 	    sun4i_pwm->data->has_prescaler_bypass)
 		prescaler = 1;
@@ -146,17 +167,27 @@
 
 static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm,
 			       const struct pwm_state *state,
-			       u32 *dty, u32 *prd, unsigned int *prsclr)
+			       u32 *dty, u32 *prd, unsigned int *prsclr,
+			       bool *bypass)
 {
 	u64 clk_rate, div = 0;
-	unsigned int pval, prescaler = 0;
+	unsigned int prescaler = 0;
 
 	clk_rate = clk_get_rate(sun4i_pwm->clk);
 
+	*bypass = sun4i_pwm->data->has_direct_mod_clk_output &&
+		  state->enabled &&
+		  (state->period * clk_rate >= NSEC_PER_SEC) &&
+		  (state->period * clk_rate < 2 * NSEC_PER_SEC) &&
+		  (state->duty_cycle * clk_rate * 2 >= NSEC_PER_SEC);
+
+	/* Skip calculation of other parameters if we bypass them */
+	if (*bypass)
+		return 0;
+
 	if (sun4i_pwm->data->has_prescaler_bypass) {
 		/* First, test without any prescaler when available */
 		prescaler = PWM_PRESCAL_MASK;
-		pval = 1;
 		/*
 		 * When not using any prescaler, the clock period in nanoseconds
 		 * is not an integer so round it half up instead of
@@ -171,9 +202,11 @@
 	if (prescaler == 0) {
 		/* Go up from the first divider */
 		for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
-			if (!prescaler_table[prescaler])
+			unsigned int pval = prescaler_table[prescaler];
+
+			if (!pval)
 				continue;
-			pval = prescaler_table[prescaler];
+
 			div = clk_rate;
 			do_div(div, pval);
 			div = div * state->period;
@@ -200,10 +233,11 @@
 {
 	struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
 	struct pwm_state cstate;
-	u32 ctrl;
+	u32 ctrl, duty = 0, period = 0, val;
 	int ret;
-	unsigned int delay_us;
+	unsigned int delay_us, prescaler = 0;
 	unsigned long now;
+	bool bypass;
 
 	pwm_get_state(pwm, &cstate);
 
@@ -215,52 +249,53 @@
 		}
 	}
 
+	ret = sun4i_pwm_calculate(sun4i_pwm, state, &duty, &period, &prescaler,
+				  &bypass);
+	if (ret) {
+		dev_err(chip->dev, "period exceeds the maximum value\n");
+		if (!cstate.enabled)
+			clk_disable_unprepare(sun4i_pwm->clk);
+		return ret;
+	}
+
 	spin_lock(&sun4i_pwm->ctrl_lock);
 	ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
 
-	if ((cstate.period != state->period) ||
-	    (cstate.duty_cycle != state->duty_cycle)) {
-		u32 period, duty, val;
-		unsigned int prescaler;
-
-		ret = sun4i_pwm_calculate(sun4i_pwm, state,
-					  &duty, &period, &prescaler);
-		if (ret) {
-			dev_err(chip->dev, "period exceeds the maximum value\n");
-			spin_unlock(&sun4i_pwm->ctrl_lock);
-			if (!cstate.enabled)
-				clk_disable_unprepare(sun4i_pwm->clk);
-			return ret;
-		}
-
-		if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) {
-			/* Prescaler changed, the clock has to be gated */
-			ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+	if (sun4i_pwm->data->has_direct_mod_clk_output) {
+		if (bypass) {
+			ctrl |= BIT_CH(PWM_BYPASS, pwm->hwpwm);
+			/* We can skip other parameter */
 			sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
-
-			ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
-			ctrl |= BIT_CH(prescaler, pwm->hwpwm);
+			spin_unlock(&sun4i_pwm->ctrl_lock);
+			return 0;
 		}
 
-		val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
-		sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
-		sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
-			usecs_to_jiffies(cstate.period / 1000 + 1);
-		sun4i_pwm->needs_delay[pwm->hwpwm] = true;
+		ctrl &= ~BIT_CH(PWM_BYPASS, pwm->hwpwm);
 	}
 
+	if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) {
+		/* Prescaler changed, the clock has to be gated */
+		ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+		sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
+
+		ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
+		ctrl |= BIT_CH(prescaler, pwm->hwpwm);
+	}
+
+	val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
+	sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
+	sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
+		nsecs_to_jiffies(cstate.period + 1000);
+
 	if (state->polarity != PWM_POLARITY_NORMAL)
 		ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
 	else
 		ctrl |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
 
 	ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
-	if (state->enabled) {
+
+	if (state->enabled)
 		ctrl |= BIT_CH(PWM_EN, pwm->hwpwm);
-	} else if (!sun4i_pwm->needs_delay[pwm->hwpwm]) {
-		ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
-		ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
-	}
 
 	sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
 
@@ -269,15 +304,9 @@
 	if (state->enabled)
 		return 0;
 
-	if (!sun4i_pwm->needs_delay[pwm->hwpwm]) {
-		clk_disable_unprepare(sun4i_pwm->clk);
-		return 0;
-	}
-
 	/* We need a full period to elapse before disabling the channel. */
 	now = jiffies;
-	if (sun4i_pwm->needs_delay[pwm->hwpwm] &&
-	    time_before(now, sun4i_pwm->next_period[pwm->hwpwm])) {
+	if (time_before(now, sun4i_pwm->next_period[pwm->hwpwm])) {
 		delay_us = jiffies_to_usecs(sun4i_pwm->next_period[pwm->hwpwm] -
 					   now);
 		if ((delay_us / 500) > MAX_UDELAY_MS)
@@ -285,7 +314,6 @@
 		else
 			usleep_range(delay_us, delay_us * 2);
 	}
-	sun4i_pwm->needs_delay[pwm->hwpwm] = false;
 
 	spin_lock(&sun4i_pwm->ctrl_lock);
 	ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
@@ -320,6 +348,18 @@
 	.npwm = 1,
 };
 
+static const struct sun4i_pwm_data sun50i_a64_pwm_data = {
+	.has_prescaler_bypass = true,
+	.has_direct_mod_clk_output = true,
+	.npwm = 1,
+};
+
+static const struct sun4i_pwm_data sun50i_h6_pwm_data = {
+	.has_prescaler_bypass = true,
+	.has_direct_mod_clk_output = true,
+	.npwm = 2,
+};
+
 static const struct of_device_id sun4i_pwm_dt_ids[] = {
 	{
 		.compatible = "allwinner,sun4i-a10-pwm",
@@ -337,6 +377,12 @@
 		.compatible = "allwinner,sun8i-h3-pwm",
 		.data = &sun4i_pwm_single_bypass,
 	}, {
+		.compatible = "allwinner,sun50i-a64-pwm",
+		.data = &sun50i_a64_pwm_data,
+	}, {
+		.compatible = "allwinner,sun50i-h6-pwm",
+		.data = &sun50i_h6_pwm_data,
+	}, {
 		/* sentinel */
 	},
 };
@@ -361,9 +407,57 @@
 	if (IS_ERR(pwm->base))
 		return PTR_ERR(pwm->base);
 
-	pwm->clk = devm_clk_get(&pdev->dev, NULL);
+	/*
+	 * All hardware variants need a source clock that is divided and
+	 * then feeds the counter that defines the output wave form. In the
+	 * device tree this clock is either unnamed or called "mod".
+	 * Some variants (e.g. H6) need another clock to access the
+	 * hardware registers; this is called "bus".
+	 * So we request "mod" first (and ignore the corner case that a
+	 * parent provides a "mod" clock while the right one would be the
+	 * unnamed one of the PWM device) and if this is not found we fall
+	 * back to the first clock of the PWM.
+	 */
+	pwm->clk = devm_clk_get_optional(&pdev->dev, "mod");
 	if (IS_ERR(pwm->clk))
-		return PTR_ERR(pwm->clk);
+		return dev_err_probe(&pdev->dev, PTR_ERR(pwm->clk),
+				     "get mod clock failed\n");
+
+	if (!pwm->clk) {
+		pwm->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(pwm->clk))
+			return dev_err_probe(&pdev->dev, PTR_ERR(pwm->clk),
+					     "get unnamed clock failed\n");
+	}
+
+	pwm->bus_clk = devm_clk_get_optional(&pdev->dev, "bus");
+	if (IS_ERR(pwm->bus_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(pwm->bus_clk),
+				     "get bus clock failed\n");
+
+	pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(pwm->rst))
+		return dev_err_probe(&pdev->dev, PTR_ERR(pwm->rst),
+				     "get reset failed\n");
+
+	/* Deassert reset */
+	ret = reset_control_deassert(pwm->rst);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot deassert reset control: %pe\n",
+			ERR_PTR(ret));
+		return ret;
+	}
+
+	/*
+	 * We're keeping the bus clock on for the sake of simplicity.
+	 * Actually it only needs to be on for hardware register accesses.
+	 */
+	ret = clk_prepare_enable(pwm->bus_clk);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot prepare and enable bus_clk %pe\n",
+			ERR_PTR(ret));
+		goto err_bus;
+	}
 
 	pwm->chip.dev = &pdev->dev;
 	pwm->chip.ops = &sun4i_pwm_ops;
@@ -377,19 +471,34 @@
 	ret = pwmchip_add(&pwm->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
-		return ret;
+		goto err_pwm_add;
 	}
 
 	platform_set_drvdata(pdev, pwm);
 
 	return 0;
+
+err_pwm_add:
+	clk_disable_unprepare(pwm->bus_clk);
+err_bus:
+	reset_control_assert(pwm->rst);
+
+	return ret;
 }
 
 static int sun4i_pwm_remove(struct platform_device *pdev)
 {
 	struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
+	int ret;
 
-	return pwmchip_remove(&pwm->chip);
+	ret = pwmchip_remove(&pwm->chip);
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(pwm->bus_clk);
+	reset_control_assert(pwm->rst);
+
+	return 0;
 }
 
 static struct platform_driver sun4i_pwm_driver = {
diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index 3d55e30..8c4e665 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -4,8 +4,36 @@
  *
  * Tegra pulse-width-modulation controller driver
  *
- * Copyright (c) 2010, NVIDIA Corporation.
+ * Copyright (c) 2010-2020, NVIDIA Corporation.
  * Based on arch/arm/plat-mxc/pwm.c by Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * Overview of Tegra Pulse Width Modulator Register:
+ * 1. 13-bit: Frequency division (SCALE)
+ * 2. 8-bit : Pulse division (DUTY)
+ * 3. 1-bit : Enable bit
+ *
+ * The PWM clock frequency is divided by 256 before subdividing it based
+ * on the programmable frequency division value to generate the required
+ * frequency for PWM output. The maximum output frequency that can be
+ * achieved is (max rate of source clock) / 256.
+ * e.g. if source clock rate is 408 MHz, maximum output frequency can be:
+ * 408 MHz/256 = 1.6 MHz.
+ * This 1.6 MHz frequency can further be divided using SCALE value in PWM.
+ *
+ * PWM pulse width: 8 bits are usable [23:16] for varying pulse width.
+ * To achieve 100% duty cycle, program Bit [24] of this register to
+ * 1’b1. In which case the other bits [23:16] are set to don't care.
+ *
+ * Limitations:
+ * -	When PWM is disabled, the output is driven to inactive.
+ * -	It does not allow the current PWM period to complete and
+ *	stops abruptly.
+ *
+ * -	If the register is reconfigured while PWM is running,
+ *	it does not complete the currently running period.
+ *
+ * -	If the user input duty is beyond acceptible limits,
+ *	-EINVAL is returned.
  */
 
 #include <linux/clk.h>
@@ -41,6 +69,7 @@
 	struct reset_control*rst;
 
 	unsigned long clk_rate;
+	unsigned long min_period_ns;
 
 	void __iomem *regs;
 
@@ -68,7 +97,7 @@
 {
 	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
 	unsigned long long c = duty_ns, hz;
-	unsigned long rate;
+	unsigned long rate, required_clk_rate;
 	u32 val = 0;
 	int err;
 
@@ -83,9 +112,47 @@
 	val = (u32)c << PWM_DUTY_SHIFT;
 
 	/*
+	 *  min period = max clock limit >> PWM_DUTY_WIDTH
+	 */
+	if (period_ns < pc->min_period_ns)
+		return -EINVAL;
+
+	/*
 	 * Compute the prescaler value for which (1 << PWM_DUTY_WIDTH)
 	 * cycles at the PWM clock rate will take period_ns nanoseconds.
+	 *
+	 * num_channels: If single instance of PWM controller has multiple
+	 * channels (e.g. Tegra210 or older) then it is not possible to
+	 * configure separate clock rates to each of the channels, in such
+	 * case the value stored during probe will be referred.
+	 *
+	 * If every PWM controller instance has one channel respectively, i.e.
+	 * nums_channels == 1 then only the clock rate can be modified
+	 * dynamically (e.g. Tegra186 or Tegra194).
 	 */
+	if (pc->soc->num_channels == 1) {
+		/*
+		 * Rate is multiplied with 2^PWM_DUTY_WIDTH so that it matches
+		 * with the maximum possible rate that the controller can
+		 * provide. Any further lower value can be derived by setting
+		 * PFM bits[0:12].
+		 *
+		 * required_clk_rate is a reference rate for source clock and
+		 * it is derived based on user requested period. By setting the
+		 * source clock rate as required_clk_rate, PWM controller will
+		 * be able to configure the requested period.
+		 */
+		required_clk_rate =
+			(NSEC_PER_SEC / period_ns) << PWM_DUTY_WIDTH;
+
+		err = clk_set_rate(pc->clk, required_clk_rate);
+		if (err < 0)
+			return -EINVAL;
+
+		/* Store the new rate for further references */
+		pc->clk_rate = clk_get_rate(pc->clk);
+	}
+
 	rate = pc->clk_rate >> PWM_DUTY_WIDTH;
 
 	/* Consider precision in PWM_SCALE_WIDTH rate calculation */
@@ -94,7 +161,7 @@
 
 	/*
 	 * Since the actual PWM divider is the register's frequency divider
-	 * field minus 1, we need to decrement to get the correct value to
+	 * field plus 1, we need to decrement to get the correct value to
 	 * write to the register.
 	 */
 	if (rate > 0)
@@ -205,6 +272,10 @@
 	 */
 	pwm->clk_rate = clk_get_rate(pwm->clk);
 
+	/* Set minimum limit of PWM period for the IP */
+	pwm->min_period_ns =
+	    (NSEC_PER_SEC / (pwm->soc->max_frequency >> PWM_DUTY_WIDTH)) + 1;
+
 	pwm->rst = devm_reset_control_get_exclusive(&pdev->dev, "pwm");
 	if (IS_ERR(pwm->rst)) {
 		ret = PTR_ERR(pwm->rst);
@@ -269,9 +340,15 @@
 	.max_frequency = 102000000UL,
 };
 
+static const struct tegra_pwm_soc tegra194_pwm_soc = {
+	.num_channels = 1,
+	.max_frequency = 408000000UL,
+};
+
 static const struct of_device_id tegra_pwm_of_match[] = {
 	{ .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
 	{ .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
+	{ .compatible = "nvidia,tegra194-pwm", .data = &tegra194_pwm_soc },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
@@ -293,5 +370,6 @@
 module_platform_driver(tegra_pwm_driver);
 
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("NVIDIA Corporation");
+MODULE_AUTHOR("Sandipan Patra <spatra@nvidia.com>");
+MODULE_DESCRIPTION("Tegra PWM controller driver");
 MODULE_ALIAS("platform:tegra-pwm");
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index ab38c82..683804c 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -2,7 +2,7 @@
 /*
  * ECAP PWM driver
  *
- * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
+ * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
  */
 
 #include <linux/module.h>
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 7b4c770..0846917 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -2,7 +2,7 @@
 /*
  * EHRPWM PWM driver
  *
- * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
+ * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
  */
 
 #include <linux/module.h>
diff --git a/drivers/pwm/pwm-tipwmss.c b/drivers/pwm/pwm-tipwmss.c
deleted file mode 100644
index e9c26c9..0000000
--- a/drivers/pwm/pwm-tipwmss.c
+++ /dev/null
@@ -1,55 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * TI PWM Subsystem driver
- *
- * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
- */
-
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/io.h>
-#include <linux/err.h>
-#include <linux/pm_runtime.h>
-#include <linux/of_device.h>
-
-static const struct of_device_id pwmss_of_match[] = {
-	{ .compatible	= "ti,am33xx-pwmss" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, pwmss_of_match);
-
-static int pwmss_probe(struct platform_device *pdev)
-{
-	int ret;
-	struct device_node *node = pdev->dev.of_node;
-
-	pm_runtime_enable(&pdev->dev);
-
-	/* Populate all the child nodes here... */
-	ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
-	if (ret)
-		dev_err(&pdev->dev, "no child node found\n");
-
-	return ret;
-}
-
-static int pwmss_remove(struct platform_device *pdev)
-{
-	pm_runtime_disable(&pdev->dev);
-	return 0;
-}
-
-static struct platform_driver pwmss_driver = {
-	.driver	= {
-		.name	= "pwmss",
-		.of_match_table	= pwmss_of_match,
-	},
-	.probe	= pwmss_probe,
-	.remove	= pwmss_remove,
-};
-
-module_platform_driver(pwmss_driver);
-
-MODULE_DESCRIPTION("PWM Subsystem driver");
-MODULE_AUTHOR("Texas Instruments");
-MODULE_LICENSE("GPL");
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 2389b86..9903c3a 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -42,7 +42,7 @@
 
 	pwm_get_state(pwm, &state);
 
-	return sprintf(buf, "%u\n", state.period);
+	return sprintf(buf, "%llu\n", state.period);
 }
 
 static ssize_t period_store(struct device *child,
@@ -52,10 +52,10 @@
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
 	struct pwm_state state;
-	unsigned int val;
+	u64 val;
 	int ret;
 
-	ret = kstrtouint(buf, 0, &val);
+	ret = kstrtou64(buf, 0, &val);
 	if (ret)
 		return ret;
 
@@ -77,7 +77,7 @@
 
 	pwm_get_state(pwm, &state);
 
-	return sprintf(buf, "%u\n", state.duty_cycle);
+	return sprintf(buf, "%llu\n", state.duty_cycle);
 }
 
 static ssize_t duty_cycle_store(struct device *child,
@@ -87,10 +87,10 @@
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
 	struct pwm_state state;
-	unsigned int val;
+	u64 val;
 	int ret;
 
-	ret = kstrtouint(buf, 0, &val);
+	ret = kstrtou64(buf, 0, &val);
 	if (ret)
 		return ret;