Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 4721a26..75bbfe5 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Intel Low Power Subsystem PWM controller driver
  *
@@ -7,10 +8,6 @@
  * Author: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
  * Author: Chew Chiau Ee <chiau.ee.chew@intel.com>
  * Author: Alan Cox <alan@linux.intel.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/delay.h>
@@ -32,15 +29,6 @@
 /* Size of each PWM register space if multiple */
 #define PWM_SIZE			0x400
 
-#define MAX_PWMS			4
-
-struct pwm_lpss_chip {
-	struct pwm_chip chip;
-	void __iomem *regs;
-	const struct pwm_lpss_boardinfo *info;
-	u32 saved_ctrl[MAX_PWMS];
-};
-
 static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip)
 {
 	return container_of(chip, struct pwm_lpss_chip, chip);
@@ -97,7 +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 ctrl;
+	u32 orig_ctrl, ctrl;
 
 	do_div(freq, period_ns);
 
@@ -114,13 +102,17 @@
 	do_div(on_time_div, period_ns);
 	on_time_div = 255ULL - on_time_div;
 
-	ctrl = pwm_lpss_read(pwm);
+	orig_ctrl = ctrl = pwm_lpss_read(pwm);
 	ctrl &= ~PWM_ON_TIME_DIV_MASK;
 	ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT);
 	base_unit &= base_unit_range;
 	ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
 	ctrl |= on_time_div;
-	pwm_lpss_write(pwm, ctrl);
+
+	if (orig_ctrl != ctrl) {
+		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)
@@ -130,7 +122,7 @@
 }
 
 static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
-			  struct pwm_state *state)
+			  const struct pwm_state *state)
 {
 	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
 	int ret;
@@ -144,7 +136,6 @@
 				return ret;
 			}
 			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_SW_UPDATE);
 			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
 			ret = pwm_lpss_wait_for_update(pwm);
 			if (ret) {
@@ -157,7 +148,6 @@
 			if (ret)
 				return ret;
 			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_SW_UPDATE);
 			return pwm_lpss_wait_for_update(pwm);
 		}
 	} else if (pwm_is_enabled(pwm)) {
@@ -168,8 +158,42 @@
 	return 0;
 }
 
+/* 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)
+{
+	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
+	unsigned long base_unit_range;
+	unsigned long long base_unit, freq, on_time_div;
+	u32 ctrl;
+
+	base_unit_range = BIT(lpwm->info->base_unit_bits);
+
+	ctrl = pwm_lpss_read(pwm);
+	on_time_div = 255 - (ctrl & PWM_ON_TIME_DIV_MASK);
+	base_unit = (ctrl >> PWM_BASE_UNIT_SHIFT) & (base_unit_range - 1);
+
+	freq = base_unit * lpwm->info->clk_rate;
+	do_div(freq, base_unit_range);
+	if (freq == 0)
+		state->period = NSEC_PER_SEC;
+	else
+		state->period = NSEC_PER_SEC / (unsigned long)freq;
+
+	on_time_div *= state->period;
+	do_div(on_time_div, 255);
+	state->duty_cycle = on_time_div;
+
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = !!(ctrl & PWM_ENABLE);
+
+	if (state->enabled)
+		pm_runtime_get(chip->dev);
+}
+
 static const struct pwm_ops pwm_lpss_ops = {
 	.apply = pwm_lpss_apply,
+	.get_state = pwm_lpss_get_state,
 	.owner = THIS_MODULE,
 };
 
@@ -214,6 +238,12 @@
 
 int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
 {
+	int i;
+
+	for (i = 0; i < lpwm->info->npwm; i++) {
+		if (pwm_is_enabled(&lpwm->chip.pwms[i]))
+			pm_runtime_put(lpwm->chip.dev);
+	}
 	return pwmchip_remove(&lpwm->chip);
 }
 EXPORT_SYMBOL_GPL(pwm_lpss_remove);