Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 0059b24..67fca62 100644
--- a/drivers/pwm/pwm-stm32-lp.c
+++ b/drivers/pwm/pwm-stm32-lp.c
@@ -13,6 +13,7 @@
 #include <linux/mfd/stm32-lptimer.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 
@@ -31,7 +32,7 @@
 #define STM32_LPTIM_MAX_PRESCALER	128
 
 static int stm32_pwm_lp_apply(struct pwm_chip *chip, struct pwm_device *pwm,
-			      struct pwm_state *state)
+			      const struct pwm_state *state)
 {
 	struct stm32_pwm_lp *priv = to_stm32_pwm_lp(chip);
 	unsigned long long prd, div, dty;
@@ -58,6 +59,12 @@
 	/* Calculate the period and prescaler value */
 	div = (unsigned long long)clk_get_rate(priv->clk) * state->period;
 	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);
+		return -EINVAL;
+	}
+
 	prd = div;
 	while (div > STM32_LPTIM_MAX_ARR) {
 		presc++;
@@ -223,6 +230,29 @@
 	return pwmchip_remove(&priv->chip);
 }
 
+static int __maybe_unused stm32_pwm_lp_suspend(struct device *dev)
+{
+	struct stm32_pwm_lp *priv = dev_get_drvdata(dev);
+	struct pwm_state state;
+
+	pwm_get_state(&priv->chip.pwms[0], &state);
+	if (state.enabled) {
+		dev_err(dev, "The consumer didn't stop us (%s)\n",
+			priv->chip.pwms[0].label);
+		return -EBUSY;
+	}
+
+	return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int __maybe_unused stm32_pwm_lp_resume(struct device *dev)
+{
+	return pinctrl_pm_select_default_state(dev);
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_pwm_lp_pm_ops, stm32_pwm_lp_suspend,
+			 stm32_pwm_lp_resume);
+
 static const struct of_device_id stm32_pwm_lp_of_match[] = {
 	{ .compatible = "st,stm32-pwm-lp", },
 	{},
@@ -235,6 +265,7 @@
 	.driver	= {
 		.name = "stm32-pwm-lp",
 		.of_match_table = of_match_ptr(stm32_pwm_lp_of_match),
+		.pm = &stm32_pwm_lp_pm_ops,
 	},
 };
 module_platform_driver(stm32_pwm_lp_driver);