Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
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);
 }