Merge tag 'pwm/for-5.7-rc1' of...

Merge tag 'pwm/for-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "There's quite a few changes this time around.

  Most of these are fixes and cleanups, but there's also new chip
  support for some drivers and a bit of rework"

* tag 'pwm/for-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (33 commits)
  pwm: pca9685: Fix PWM/GPIO inter-operation
  pwm: Make pwm_apply_state_debug() static
  pwm: meson: Remove redundant assignment to variable fin_freq
  pwm: jz4740: Allow selection of PWM channels 0 and 1
  pwm: jz4740: Obtain regmap from parent node
  pwm: jz4740: Improve algorithm of clock calculation
  pwm: jz4740: Use clocks from TCU driver
  pwm: sun4i: Remove redundant needs_delay
  pwm: omap-dmtimer: Implement .apply callback
  pwm: omap-dmtimer: Do not disable PWM before changing period/duty_cycle
  pwm: omap-dmtimer: Fix PWM enabling sequence
  pwm: omap-dmtimer: Update description for PWM OMAP DM timer
  pwm: omap-dmtimer: Drop unused header file
  pwm: renesas-tpu: Drop confusing registered message
  pwm: renesas-tpu: Fix late Runtime PM enablement
  pwm: rcar: Fix late Runtime PM enablement
  dt-bindings: pwm: renesas-tpu: Document more R-Car Gen2 support
  pwm: meson: Fix confusing indentation
  pwm: pca9685: Use gpio core provided macro GPIO_LINE_DIRECTION_OUT
  pwm: pca9685: Replace CONFIG_PM with __maybe_unused
  ...

Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.txt

-* PWM controlled by ChromeOS EC
-
-Google's ChromeOS EC PWM is a simple PWM attached to the Embedded Controller
-(EC) and controlled via a host-command interface.
-
-An EC PWM node should be only found as a sub-node of the EC node (see
-Documentation/devicetree/bindings/mfd/cros-ec.txt).
-
-Required properties:
-- compatible: Must contain "google,cros-ec-pwm"
-- #pwm-cells: Should be 1. The cell specifies the PWM index.
-
-Example:
-	cros-ec@0 {
-		compatible = "google,cros-ec-spi";
-
-		...
-
-		cros_ec_pwm: ec-pwm {
-			compatible = "google,cros-ec-pwm";
-			#pwm-cells = <1>;
-		};
-	};

Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/google,cros-ec-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PWM controlled by ChromeOS EC
+
+maintainers:
+  - Thierry Reding <thierry.reding@gmail.com>
+  - '"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>'
+
+description: |
+  Google's ChromeOS EC PWM is a simple PWM attached to the Embedded Controller
+  (EC) and controlled via a host-command interface.
+  An EC PWM node should be only found as a sub-node of the EC node (see
+  Documentation/devicetree/bindings/mfd/cros-ec.txt).
+
+properties:
+  compatible:
+    const: google,cros-ec-pwm
+  "#pwm-cells":
+    description: The cell specifies the PWM index.
+    const: 1
+
+required:
+  - compatible
+  - '#pwm-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    cros-ec@0 {
+        compatible = "google,cros-ec-spi";
+        cros_ec_pwm: ec-pwm {
+            compatible = "google,cros-ec-pwm";
+            #pwm-cells = <1>;
+        };
+    };

Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt

@@ -9,6 +9,7 @@ Required properties:
   - "nvidia,tegra132-pwm", "nvidia,tegra20-pwm": for Tegra132
   - "nvidia,tegra210-pwm", "nvidia,tegra20-pwm": for Tegra210
   - "nvidia,tegra186-pwm": for Tegra186
+  - "nvidia,tegra194-pwm": for Tegra194
 - reg: physical base address and length of the controller's registers
 - #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
   the cells format.

drivers/pwm/Kconfig

@@ -33,6 +33,15 @@ config PWM_SYSFS
 	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_AB8500
 
 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_BCM_KONA
 
 config PWM_BCM2835
 	tristate "BCM2835 PWM support"
-	depends on ARCH_BCM2835 || ARCH_BRCMSTB
+	depends on ARCH_BCM2835 || ARCH_BRCMSTB || COMPILE_TEST
 	help
 	  PWM framework driver for BCM2835 controller (Raspberry Pi)
 
@@ -109,7 +119,7 @@ config PWM_BCM2835
 
 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_BERLIN
 
 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_CROS_EC
 
 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_IMG
 
 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_IMX1
 
 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.
 
@@ -225,6 +235,8 @@ config PWM_IMX_TPM
 config PWM_JZ4740
 	tristate "Ingenic JZ47xx PWM support"
 	depends on MACH_INGENIC
+	depends on COMMON_CLK
+	select MFD_SYSCON
 	help
 	  Generic PWM framework driver for Ingenic JZ47xx based
 	  machines.
@@ -244,7 +256,7 @@ config PWM_LP3943
 
 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 +268,7 @@ config PWM_LPC18XX_SCT
 
 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 +301,8 @@ config PWM_LPSS_PLATFORM
 
 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 +331,8 @@ config PWM_MEDIATEK
 
 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.
@@ -357,7 +371,7 @@ config 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.
 
@@ -388,14 +402,14 @@ config PWM_RENESAS_TPU
 
 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_EXYNOS || COMPILE_TEST
 	help
 	  Generic PWM framework driver for Samsung.
 
@@ -415,7 +429,7 @@ config PWM_SIFIVE
 
 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
@@ -437,7 +451,7 @@ config PWM_SPRD
 
 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.
@@ -447,7 +461,7 @@ config PWM_STI
 
 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.
 
@@ -483,7 +497,7 @@ config PWM_SUN4I
 
 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.
@@ -493,7 +507,7 @@ config PWM_TEGRA
 
 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
 
@@ -502,7 +516,7 @@ config PWM_TIECAP
 
 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
 
@@ -529,7 +543,7 @@ config PWM_TWL_LED
 
 config PWM_VT8500
 	tristate "vt8500 PWM support"
-	depends on ARCH_VT8500
+	depends on ARCH_VT8500 || COMPILE_TEST
 	help
 	  Generic PWM framework driver for vt8500.
 
@@ -538,7 +552,7 @@ config PWM_VT8500
 
 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.
 

drivers/pwm/core.c

@@ -120,6 +120,9 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
 	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(PWM_DEBUG))
+			pwm->last = pwm->state;
 	}
 
 	set_bit(PWMF_REQUESTED, &pwm->flags);
@@ -232,17 +235,28 @@ void *pwm_get_chip_data(struct pwm_device *pwm)
 }
 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;
 }
 
 /**
@@ -266,7 +280,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 	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);
@@ -450,6 +464,107 @@ void pwm_free(struct pwm_device *pwm)
 }
 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: %u, applied: %u, possible: %u)\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: %u, applied: %u)\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: %u/%u, applied: %u/%u, possible: %u/%u)\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: %u/%u, applied: %u/%u)\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");
+
+	/* 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 %u/%u) -> (ena=%d pol=%d %u/%u)\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
@@ -480,6 +595,12 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
 		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.

drivers/pwm/pwm-bcm2835.c

@@ -166,6 +166,7 @@ static int bcm2835_pwm_probe(struct platform_device *pdev)
 
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &bcm2835_pwm_ops;
+	pc->chip.base = -1;
 	pc->chip.npwm = 2;
 	pc->chip.of_xlate = of_pwm_xlate_with_flags;
 	pc->chip.of_pwm_n_cells = 3;

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>

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>
@@ -96,9 +95,8 @@ struct pwm_imx27_chip {
 
 #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);
@@ -114,10 +112,8 @@ static int pwm_imx27_clk_prepare_enable(struct pwm_chip *chip)
 	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);
 }
@@ -130,7 +126,7 @@ static void pwm_imx27_get_state(struct pwm_chip *chip,
 	u64 tmp;
 	int ret;
 
-	ret = pwm_imx27_clk_prepare_enable(chip);
+	ret = pwm_imx27_clk_prepare_enable(imx);
 	if (ret < 0)
 		return;
 
@@ -174,8 +170,7 @@ static void pwm_imx27_get_state(struct pwm_chip *chip,
 	tmp = NSEC_PER_SEC * (u64)(val);
 	state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk);
 
-	if (!state->enabled)
-		pwm_imx27_clk_disable_unprepare(chip);
+	pwm_imx27_clk_disable_unprepare(imx);
 }
 
 static void pwm_imx27_sw_reset(struct pwm_chip *chip)
@@ -259,7 +254,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (cstate.enabled) {
 		pwm_imx27_wait_fifo_slot(chip, pwm);
 	} else {
-		ret = pwm_imx27_clk_prepare_enable(chip);
+		ret = pwm_imx27_clk_prepare_enable(imx);
 		if (ret)
 			return ret;
 
@@ -289,8 +284,8 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	writel(cr, imx->mmio_base + MX3_PWMCR);
 
-	if (!state->enabled && cstate.enabled)
-		pwm_imx27_clk_disable_unprepare(chip);
+	if (!state->enabled)
+		pwm_imx27_clk_disable_unprepare(imx);
 
 	return 0;
 }
@@ -310,6 +305,8 @@ MODULE_DEVICE_TABLE(of, pwm_imx27_dt_ids);
 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)
@@ -352,6 +349,15 @@ static int pwm_imx27_probe(struct platform_device *pdev)
 	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);
 }
 
@@ -361,8 +367,6 @@ static int pwm_imx27_remove(struct platform_device *pdev)
 
 	imx = platform_get_drvdata(pdev);
 
-	pwm_imx27_clk_disable_unprepare(&imx->chip);
-
 	return pwmchip_remove(&imx->chip);
 }
 

drivers/pwm/pwm-jz4740.c

@@ -13,18 +13,19 @@
 #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 <asm/mach-jz4740/timer.h>
+#include <linux/regmap.h>
 
 #define NUM_PWM 8
 
 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)
@@ -32,82 +33,134 @@ static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
 	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(NUM_PWM - 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)) {
+		if (PTR_ERR(clk) != -EPROBE_DEFER)
+			dev_err(chip->dev, "Failed to get clock: %pe", clk);
+
+		return PTR_ERR(clk);
+	}
+
+	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);
+
+	/* Enable PWM output */
+	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+			   TCU_TCSR_PWM_EN, TCU_TCSR_PWM_EN);
 
-	ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-	jz4740_timer_enable(pwm->hwpwm);
+	/* 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 long tmp = 0xffffull * NSEC_PER_SEC;
+	struct clk *clk = pwm_get_chip_data(pwm);
 	unsigned long period, duty;
-	unsigned int prescaler = 0;
-	uint16_t ctrl;
+	long rate;
+	int err;
 
-	tmp = (unsigned long long)clk_get_rate(jz4740->clk) * 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 = (unsigned long)tmp;
 
+	/* Calculate duty value */
 	tmp = (unsigned long long)period * state->duty_cycle;
 	do_div(tmp, state->period);
 	duty = period - tmp;
@@ -117,26 +170,38 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	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);
+	err = clk_set_rate(clk, rate);
+	if (err) {
+		dev_err(chip->dev, "Unable to set rate: %d", err);
+		return err;
+	}
+
+	/* Reset counter to 0 */
+	regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);
 
-	ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
-		JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
+	/* Set duty */
+	regmap_write(jz4740->map, TCU_REG_TDHRc(pwm->hwpwm), duty);
 
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+	/* 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 */
 	switch (state->polarity) {
 	case PWM_POLARITY_NORMAL:
-		ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+				   TCU_TCSR_PWM_INITL_HIGH, 0);
 		break;
 	case PWM_POLARITY_INVERSED:
-		ctrl |= JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+				   TCU_TCSR_PWM_INITL_HIGH,
+				   TCU_TCSR_PWM_INITL_HIGH);
 		break;
 	}
 
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-
 	if (state->enabled)
 		jz4740_pwm_enable(chip, pwm);
 
@@ -152,17 +217,20 @@ static const struct pwm_ops jz4740_pwm_ops = {
 
 static int jz4740_pwm_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct jz4740_pwm_chip *jz4740;
 
-	jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
+	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.base = -1;

drivers/pwm/pwm-meson.c

@@ -136,7 +136,7 @@ static int meson_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 			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 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
 {
 	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;

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>

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: http://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 @@ to_pwm_omap_dmtimer_chip(struct pwm_chip *chip)
 	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 @@ static void pwm_omap_dmtimer_start(struct pwm_omap_dmtimer_chip *omap)
 	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 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	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 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 		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) {
@@ -174,81 +228,103 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 	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, 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,
-			      true);
-
-	/* If config was called while timer was running it must be reenabled. */
-	if (timer_active)
-		pwm_omap_dmtimer_start(omap);
+	return 0;
+}
 
-	mutex_unlock(&omap->mutex);
+/**
+ * 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;
 
-	return 0;
+	/* Disable the PWM before changing the polarity. */
+	enabled = pwm_omap_dmtimer_is_enabled(omap);
+	if (enabled)
+		omap->pdata->stop(omap->dm_timer);
 
-err_einval:
-	mutex_unlock(&omap->mutex);
+	omap->pdata->set_pwm(omap->dm_timer,
+			     polarity == PWM_POLARITY_INVERSED,
+			     true, OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE,
+			     true);
 
-	return -EINVAL;
+	if (enabled)
+		pwm_omap_dmtimer_start(omap);
 }
 
-static int pwm_omap_dmtimer_set_polarity(struct pwm_chip *chip,
-					 struct pwm_device *pwm,
-					 enum pwm_polarity polarity)
+/**
+ * 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;
 
-	/*
-	 * 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);
-	omap->pdata->set_pwm(omap->dm_timer,
-			      polarity == PWM_POLARITY_INVERSED,
-			      true,
-			      PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE,
-			      true);
+
+	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)
@@ -281,6 +357,7 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
 	    !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");

drivers/pwm/pwm-pca9685.c

@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/pm_runtime.h>
+#include <linux/bitmap.h>
 
 /*
  * Because the PCA9685 has only one prescaler per chip, changing the period of
@@ -69,11 +70,11 @@
 struct pca9685 {
 	struct pwm_chip chip;
 	struct regmap *regmap;
-	int duty_ns;
 	int period_ns;
 #if IS_ENABLED(CONFIG_GPIOLIB)
 	struct mutex lock;
 	struct gpio_chip gpio;
+	DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
 #endif
 };
 
@@ -83,51 +84,51 @@ static inline struct pca9685 *to_pca(struct pwm_chip *chip)
 }
 
 #if IS_ENABLED(CONFIG_GPIOLIB)
-static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx)
 {
-	struct pca9685 *pca = gpiochip_get_data(gpio);
-	struct pwm_device *pwm;
+	bool is_inuse;
 
 	mutex_lock(&pca->lock);
-
-	pwm = &pca->chip.pwms[offset];
-
-	if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
-		mutex_unlock(&pca->lock);
-		return -EBUSY;
+	if (pwm_idx >= PCA9685_MAXCHAN) {
+		/*
+		 * "all LEDs" channel:
+		 * pretend already in use if any of the PWMs are requested
+		 */
+		if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
+			is_inuse = true;
+			goto out;
+		}
+	} else {
+		/*
+		 * regular channel:
+		 * pretend already in use if the "all LEDs" channel is requested
+		 */
+		if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
+			is_inuse = true;
+			goto out;
+		}
 	}
-
-	pwm_set_chip_data(pwm, (void *)1);
-
+	is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse);
+out:
 	mutex_unlock(&pca->lock);
-	pm_runtime_get_sync(pca->chip.dev);
-	return 0;
+	return is_inuse;
 }
 
-static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
+static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
 {
-	bool is_gpio = false;
-
 	mutex_lock(&pca->lock);
+	clear_bit(pwm_idx, pca->pwms_inuse);
+	mutex_unlock(&pca->lock);
+}
 
-	if (pwm->hwpwm >= PCA9685_MAXCHAN) {
-		unsigned int i;
-
-		/*
-		 * Check if any of the GPIOs are requested and in that case
-		 * prevent using the "all LEDs" channel.
-		 */
-		for (i = 0; i < pca->gpio.ngpio; i++)
-			if (gpiochip_is_requested(&pca->gpio, i)) {
-				is_gpio = true;
-				break;
-			}
-	} else if (pwm_get_chip_data(pwm)) {
-		is_gpio = true;
-	}
+static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
 
-	mutex_unlock(&pca->lock);
-	return is_gpio;
+	if (pca9685_pwm_test_and_set_inuse(pca, offset))
+		return -EBUSY;
+	pm_runtime_get_sync(pca->chip.dev);
+	return 0;
 }
 
 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
@@ -162,13 +163,14 @@ static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
 
 	pca9685_pwm_gpio_set(gpio, offset, 0);
 	pm_runtime_put(pca->chip.dev);
+	pca9685_pwm_clear_inuse(pca, offset);
 }
 
 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
 					  unsigned int offset)
 {
 	/* Always out */
-	return 0;
+	return GPIO_LINE_DIRECTION_OUT;
 }
 
 static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
@@ -213,12 +215,17 @@ static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
 	return devm_gpiochip_add_data(dev, &pca->gpio, pca);
 }
 #else
-static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
-				       struct pwm_device *pwm)
+static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
+						  int pwm_idx)
 {
 	return false;
 }
 
+static inline void
+pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
+{
+}
+
 static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
 {
 	return 0;
@@ -272,8 +279,6 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		}
 	}
 
-	pca->duty_ns = duty_ns;
-
 	if (duty_ns < 1) {
 		if (pwm->hwpwm >= PCA9685_MAXCHAN)
 			reg = PCA9685_ALL_LED_OFF_H;
@@ -402,7 +407,7 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct pca9685 *pca = to_pca(chip);
 
-	if (pca9685_pwm_is_gpio(pca, pwm))
+	if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
 		return -EBUSY;
 	pm_runtime_get_sync(chip->dev);
 
@@ -411,8 +416,11 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 
 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
+	struct pca9685 *pca = to_pca(chip);
+
 	pca9685_pwm_disable(chip, pwm);
 	pm_runtime_put(chip->dev);
+	pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
 }
 
 static const struct pwm_ops pca9685_pwm_ops = {
@@ -449,7 +457,6 @@ static int pca9685_pwm_probe(struct i2c_client *client,
 			ret);
 		return ret;
 	}
-	pca->duty_ns = 0;
 	pca->period_ns = PCA9685_DEFAULT_PERIOD;
 
 	i2c_set_clientdata(client, pca);
@@ -512,8 +519,7 @@ static int pca9685_pwm_remove(struct i2c_client *client)
 	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);
@@ -522,7 +528,7 @@ static int pca9685_pwm_runtime_suspend(struct device *dev)
 	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);
@@ -530,7 +536,6 @@ static int pca9685_pwm_runtime_resume(struct device *dev)
 	pca9685_set_sleep_mode(pca, false);
 	return 0;
 }
-#endif
 
 static const struct i2c_device_id pca9685_id[] = {
 	{ "pca9685", 0 },

drivers/pwm/pwm-rcar.c

@@ -229,24 +229,28 @@ static int rcar_pwm_probe(struct platform_device *pdev)
 	rcar_pwm->chip.base = -1;
 	rcar_pwm->chip.npwm = 1;
 
+	pm_runtime_enable(&pdev->dev);
+
 	ret = pwmchip_add(&rcar_pwm->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register PWM chip: %d\n", ret);
+		pm_runtime_disable(&pdev->dev);
 		return ret;
 	}
 
-	pm_runtime_enable(&pdev->dev);
-
 	return 0;
 }
 
 static int rcar_pwm_remove(struct platform_device *pdev)
 {
 	struct rcar_pwm_chip *rcar_pwm = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pwmchip_remove(&rcar_pwm->chip);
 
 	pm_runtime_disable(&pdev->dev);
 
-	return pwmchip_remove(&rcar_pwm->chip);
+	return ret;
 }
 
 static const struct of_device_id rcar_pwm_of_table[] = {

drivers/pwm/pwm-renesas-tpu.c

@@ -415,16 +415,15 @@ static int tpu_probe(struct platform_device *pdev)
 	tpu->chip.base = -1;
 	tpu->chip.npwm = TPU_CHANNEL_MAX;
 
+	pm_runtime_enable(&pdev->dev);
+
 	ret = pwmchip_add(&tpu->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register PWM chip\n");
+		pm_runtime_disable(&pdev->dev);
 		return ret;
 	}
 
-	dev_info(&pdev->dev, "TPU PWM %d registered\n", tpu->pdev->id);
-
-	pm_runtime_enable(&pdev->dev);
-
 	return 0;
 }
 
@@ -434,12 +433,10 @@ static int tpu_remove(struct platform_device *pdev)
 	int ret;
 
 	ret = pwmchip_remove(&tpu->chip);
-	if (ret)
-		return ret;
 
 	pm_runtime_disable(&pdev->dev);
 
-	return 0;
+	return ret;
 }
 
 #ifdef CONFIG_OF

drivers/pwm/pwm-sun4i.c

@@ -90,7 +90,6 @@ struct sun4i_pwm_chip {
 	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)
@@ -287,7 +286,6 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	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;
 
 	if (state->polarity != PWM_POLARITY_NORMAL)
 		ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
@@ -298,7 +296,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	if (state->enabled) {
 		ctrl |= BIT_CH(PWM_EN, pwm->hwpwm);
-	} else if (!sun4i_pwm->needs_delay[pwm->hwpwm]) {
+	} else {
 		ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
 		ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
 	}
@@ -310,15 +308,9 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	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)
@@ -326,7 +318,6 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 		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);

drivers/pwm/pwm-tegra.c

@@ -282,9 +282,15 @@ static const struct tegra_pwm_soc tegra186_pwm_soc = {
 	.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);

include/clocksource/timer-ti-dm.h

@@ -248,8 +248,7 @@ int omap_dm_timers_active(void);
 
 /*
  * The below are inlined to optimize code size for system timers. Other code
- * should not need these at all, see
- * include/linux/platform_data/pwm_omap_dmtimer.h
+ * should not need these at all.
  */
 #if defined(CONFIG_ARCH_OMAP1) || defined(CONFIG_ARCH_OMAP2PLUS)
 static inline u32 __omap_dm_timer_read(struct omap_dm_timer *timer, u32 reg,

include/linux/platform_data/pwm_omap_dmtimer.h

-/*
- * include/linux/platform_data/pwm_omap_dmtimer.h
- *
- * OMAP Dual-Mode Timer PWM platform data
- *
- * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
- * Tarun Kanti DebBarma <tarun.kanti@ti.com>
- * Thara Gopinath <thara@ti.com>
- *
- * Platform device conversion and hwmod support.
- *
- * Copyright (C) 2005 Nokia Corporation
- * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
- * PWM and clock framework support by Timo Teras.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
- * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * You should have received a copy of the  GNU General Public License along
- * with this program; if not, write  to the Free Software Foundation, Inc.,
- * 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#ifndef __PWM_OMAP_DMTIMER_PDATA_H
-#define __PWM_OMAP_DMTIMER_PDATA_H
-
-/* clock sources */
-#define PWM_OMAP_DMTIMER_SRC_SYS_CLK			0x00
-#define PWM_OMAP_DMTIMER_SRC_32_KHZ			0x01
-#define PWM_OMAP_DMTIMER_SRC_EXT_CLK			0x02
-
-/* timer interrupt enable bits */
-#define PWM_OMAP_DMTIMER_INT_CAPTURE			(1 << 2)
-#define PWM_OMAP_DMTIMER_INT_OVERFLOW			(1 << 1)
-#define PWM_OMAP_DMTIMER_INT_MATCH			(1 << 0)
-
-/* trigger types */
-#define PWM_OMAP_DMTIMER_TRIGGER_NONE			0x00
-#define PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW		0x01
-#define PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE	0x02
-
-struct omap_dm_timer;
-typedef struct omap_dm_timer pwm_omap_dmtimer;
-
-struct pwm_omap_dmtimer_pdata {
-	pwm_omap_dmtimer *(*request_by_node)(struct device_node *np);
-	pwm_omap_dmtimer *(*request_specific)(int timer_id);
-	pwm_omap_dmtimer *(*request)(void);
-
-	int	(*free)(pwm_omap_dmtimer *timer);
-
-	void	(*enable)(pwm_omap_dmtimer *timer);
-	void	(*disable)(pwm_omap_dmtimer *timer);
-
-	int	(*get_irq)(pwm_omap_dmtimer *timer);
-	int	(*set_int_enable)(pwm_omap_dmtimer *timer, unsigned int value);
-	int	(*set_int_disable)(pwm_omap_dmtimer *timer, u32 mask);
-
-	struct clk *(*get_fclk)(pwm_omap_dmtimer *timer);
-
-	int	(*start)(pwm_omap_dmtimer *timer);
-	int	(*stop)(pwm_omap_dmtimer *timer);
-	int	(*set_source)(pwm_omap_dmtimer *timer, int source);
-
-	int	(*set_load)(pwm_omap_dmtimer *timer, int autoreload,
-			unsigned int value);
-	int	(*set_match)(pwm_omap_dmtimer *timer, int enable,
-			unsigned int match);
-	int	(*set_pwm)(pwm_omap_dmtimer *timer, int def_on,
-			int toggle, int trigger);
-	int	(*set_prescaler)(pwm_omap_dmtimer *timer, int prescaler);
-
-	unsigned int (*read_counter)(pwm_omap_dmtimer *timer);
-	int	(*write_counter)(pwm_omap_dmtimer *timer, unsigned int value);
-	unsigned int (*read_status)(pwm_omap_dmtimer *timer);
-	int	(*write_status)(pwm_omap_dmtimer *timer, unsigned int value);
-};
-
-#endif /* __PWM_OMAP_DMTIMER_PDATA_H */

include/linux/pwm.h

@@ -71,7 +71,8 @@ struct pwm_state {
  * @chip: PWM chip providing this PWM device
  * @chip_data: chip-private data associated with the PWM device
  * @args: PWM arguments
- * @state: curent PWM channel state
+ * @state: last applied state
+ * @last: last implemented state (for PWM_DEBUG)
  */
 struct pwm_device {
 	const char *label;
@@ -83,6 +84,7 @@ struct pwm_device {
 
 	struct pwm_args args;
 	struct pwm_state state;
+	struct pwm_state last;
 };
 
 /**