Merge tag 'pwm/for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set is mostly small fixes and cleanups, so more of a janitorial
  update for this cycle"

* tag 'pwm/for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: vt8500: Rename pwm_busy_wait() to make it obviously driver-specific
  dt-bindings: pwm: tpu: Add R-Car M3-W+ device tree bindings
  dt-bindings: pwm: tpu: Add R-Car V3U device tree bindings
  pwm: pwm-samsung: Trigger manual update when disabling PWM
  pwm: visconti: Simplify using devm_pwmchip_add()
  pwm: samsung: Describe driver in Kconfig
  pwm: Make it explicit that pwm_apply_state() might sleep
  pwm: Add might_sleep() annotations for !CONFIG_PWM API functions
  pwm: atmel: Drop unused header

6 files changed, 43 insertions, 31 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index aa29841bbb79..21e3b05a5153 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -476,7 +476,9 @@ config PWM_SAMSUNG
 	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
 	depends on HAS_IOMEM
 	help
-	  Generic PWM framework driver for Samsung.
+	  Generic PWM framework driver for Samsung S3C24xx, S3C64xx, S5Pv210
+	  and Exynos SoCs.
+	  Choose Y here only if you build for such Samsung SoC.
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-samsung.
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 4527f09a5c50..fb04a439462c 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -532,6 +532,15 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
 	struct pwm_chip *chip;
 	int err;
 
+	/*
+	 * Some lowlevel driver's implementations of .apply() make use of
+	 * mutexes, also with some drivers only returning when the new
+	 * configuration is active calling pwm_apply_state() from atomic context
+	 * is a bad idea. So make it explicit that calling this function might
+	 * sleep.
+	 */
+	might_sleep();
+
 	if (!pwm || !state || !state->period ||
 	    state->duty_cycle > state->period)
 		return -EINVAL;
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index e748604403cc..98b34ea9f38e 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -24,7 +24,6 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
index dd94c4312a0c..0a4ff55fad04 100644
--- a/drivers/pwm/pwm-samsung.c
+++ b/drivers/pwm/pwm-samsung.c
@@ -117,6 +117,20 @@ static inline unsigned int to_tcon_channel(unsigned int channel)
 	return (channel == 0) ? 0 : (channel + 1);
 }
 
+static void __pwm_samsung_manual_update(struct samsung_pwm_chip *chip,
+				      struct pwm_device *pwm)
+{
+	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);
+	u32 tcon;
+
+	tcon = readl(chip->base + REG_TCON);
+	tcon |= TCON_MANUALUPDATE(tcon_chan);
+	writel(tcon, chip->base + REG_TCON);
+
+	tcon &= ~TCON_MANUALUPDATE(tcon_chan);
+	writel(tcon, chip->base + REG_TCON);
+}
+
 static void pwm_samsung_set_divisor(struct samsung_pwm_chip *pwm,
 				    unsigned int channel, u8 divisor)
 {
@@ -276,6 +290,13 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	tcon &= ~TCON_AUTORELOAD(tcon_chan);
 	writel(tcon, our_chip->base + REG_TCON);
 
+	/*
+	 * In case the PWM is at 100% duty cycle, force a manual
+	 * update to prevent the signal from staying high.
+	 */
+	if (readl(our_chip->base + REG_TCMPB(pwm->hwpwm)) == (u32)-1U)
+		__pwm_samsung_manual_update(our_chip, pwm);
+
 	our_chip->disabled_mask |= BIT(pwm->hwpwm);
 
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
@@ -284,18 +305,11 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 static void pwm_samsung_manual_update(struct samsung_pwm_chip *chip,
 				      struct pwm_device *pwm)
 {
-	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);
-	u32 tcon;
 	unsigned long flags;
 
 	spin_lock_irqsave(&samsung_pwm_lock, flags);
 
-	tcon = readl(chip->base + REG_TCON);
-	tcon |= TCON_MANUALUPDATE(tcon_chan);
-	writel(tcon, chip->base + REG_TCON);
-
-	tcon &= ~TCON_MANUALUPDATE(tcon_chan);
-	writel(tcon, chip->base + REG_TCON);
+	__pwm_samsung_manual_update(chip, pwm);
 
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
diff --git a/drivers/pwm/pwm-visconti.c b/drivers/pwm/pwm-visconti.c
index af4e37d3e3a6..927c4cbb1daf 100644
--- a/drivers/pwm/pwm-visconti.c
+++ b/drivers/pwm/pwm-visconti.c
@@ -144,28 +144,17 @@ static int visconti_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);
 
-	platform_set_drvdata(pdev, priv);
-
 	priv->chip.dev = dev;
 	priv->chip.ops = &visconti_pwm_ops;
 	priv->chip.npwm = 4;
 
-	ret = pwmchip_add(&priv->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &priv->chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "Cannot register visconti PWM\n");
 
 	return 0;
 }
 
-static int visconti_pwm_remove(struct platform_device *pdev)
-{
-	struct visconti_pwm_chip *priv = platform_get_drvdata(pdev);
-
-	pwmchip_remove(&priv->chip);
-
-	return 0;
-}
-
 static const struct of_device_id visconti_pwm_of_match[] = {
 	{ .compatible = "toshiba,visconti-pwm", },
 	{ }
@@ -178,7 +167,6 @@ static struct platform_driver visconti_pwm_driver = {
 		.of_match_table = visconti_pwm_of_match,
 	},
 	.probe = visconti_pwm_probe,
-	.remove = visconti_pwm_remove,
 };
 module_platform_driver(visconti_pwm_driver);
 
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index ea2aa151080a..480bfc29782f 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -56,7 +56,7 @@ struct vt8500_chip {
 #define to_vt8500_chip(chip)	container_of(chip, struct vt8500_chip, chip)
 
 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
-static inline void pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
+static inline void vt8500_pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
 {
 	int loops = msecs_to_loops(10);
 	u32 mask = bitmask << (nr << 8);
@@ -106,18 +106,18 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	dc = c;
 
 	writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
 
 	writel(pv, vt8500->base + REG_PERIOD(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
 
 	writel(dc, vt8500->base + REG_DUTY(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
 
 	val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
 	val |= CTRL_AUTOLOAD;
 	writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
 
 	clk_disable(vt8500->clk);
 	return 0;
@@ -138,7 +138,7 @@ static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
 	val |= CTRL_ENABLE;
 	writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
 
 	return 0;
 }
@@ -151,7 +151,7 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
 	val &= ~CTRL_ENABLE;
 	writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
 
 	clk_disable(vt8500->clk);
 }
@@ -171,7 +171,7 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
 		val &= ~CTRL_INVERT;
 
 	writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
-	pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+	vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
 
 	return 0;
 }