Merge branch 'for-4.12/drivers' into for-next

Documentation/devicetree/bindings/pwm/atmel-pwm.txt

@@ -4,6 +4,7 @@ Required properties:
   - compatible: should be one of:
     - "atmel,at91sam9rl-pwm"
     - "atmel,sama5d3-pwm"
+    - "atmel,sama5d2-pwm"
   - reg: physical base address and length of the controller's registers
   - #pwm-cells: Should be 3. See pwm.txt in this directory for a
     description of the cells format.

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

@@ -19,6 +19,19 @@ Required properties:
 - reset-names: Must include the following entries:
   - pwm
 
+Optional properties:
+============================
+In some of the interface like PWM based regulator device, it is required
+to configure the pins differently in different states, especially in suspend
+state of the system. The configuration of pin is provided via the pinctrl
+DT node as detailed in the pinctrl DT binding document
+	Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+The PWM node will have following optional properties.
+pinctrl-names:	Pin state names. Must be "default" and "sleep".
+pinctrl-0:	phandle for the default/active state of pin configurations.
+pinctrl-1:	phandle for the sleep state of pin configurations.
+
 Example:
 
 	pwm: pwm@7000a000 {
@@ -29,3 +42,35 @@ Example:
 		resets = <&tegra_car 17>;
 		reset-names = "pwm";
 	};
+
+
+Example with the pin configuration for suspend and resume:
+=========================================================
+Suppose pin PE7 (On Tegra210) interfaced with the regulator device and
+it requires PWM output to be tristated when system enters suspend.
+Following will be DT binding to achieve this:
+
+#include <dt-bindings/pinctrl/pinctrl-tegra.h>
+
+	pinmux@700008d4 {
+		pwm_active_state: pwm_active_state {
+                        pe7 {
+                                nvidia,pins = "pe7";
+                                nvidia,tristate = <TEGRA_PIN_DISABLE>;
+			};
+		};
+
+		pwm_sleep_state: pwm_sleep_state {
+                        pe7 {
+                                nvidia,pins = "pe7";
+                                nvidia,tristate = <TEGRA_PIN_ENABLE>;
+			};
+		};
+	};
+
+	pwm@7000a000 {
+		/* Mandatory PWM properties */
+		pinctrl-names = "default", "sleep";
+		pinctrl-0 = <&pwm_active_state>;
+		pinctrl-1 = <&pwm_sleep_state>;
+	};

Documentation/devicetree/bindings/pwm/pwm-mediatek.txt

+MediaTek PWM controller
+
+Required properties:
+ - compatible: should be "mediatek,<name>-pwm":
+   - "mediatek,mt7623-pwm": found on mt7623 SoC.
+ - reg: physical base address and length of the controller's registers.
+ - #pwm-cells: must be 2. See pwm.txt in this directory for a description of
+   the cell format.
+ - clocks: phandle and clock specifier of the PWM reference clock.
+ - clock-names: must contain the following:
+   - "top": the top clock generator
+   - "main": clock used by the PWM core
+   - "pwm1-5": the five per PWM clocks
+ - pinctrl-names: Must contain a "default" entry.
+ - pinctrl-0: One property must exist for each entry in pinctrl-names.
+   See pinctrl/pinctrl-bindings.txt for details of the property values.
+
+Example:
+	pwm0: pwm@11006000 {
+		compatible = "mediatek,mt7623-pwm";
+		reg = <0 0x11006000 0 0x1000>;
+		#pwm-cells = <2>;
+		clocks = <&topckgen CLK_TOP_PWM_SEL>,
+			 <&pericfg CLK_PERI_PWM>,
+			 <&pericfg CLK_PERI_PWM1>,
+			 <&pericfg CLK_PERI_PWM2>,
+			 <&pericfg CLK_PERI_PWM3>,
+			 <&pericfg CLK_PERI_PWM4>,
+			 <&pericfg CLK_PERI_PWM5>;
+		clock-names = "top", "main", "pwm1", "pwm2",
+			      "pwm3", "pwm4", "pwm5";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pwm0_pins>;
+	};

drivers/pwm/Kconfig

@@ -293,6 +293,15 @@ config PWM_MTK_DISP
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-mtk-disp.
 
+config PWM_MEDIATEK
+	tristate "MediaTek PWM support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  Generic PWM framework driver for Mediatek ARM SoC.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-mxs.
+
 config PWM_MXS
 	tristate "Freescale MXS PWM support"
 	depends on ARCH_MXS && OF

drivers/pwm/Makefile

@@ -26,6 +26,7 @@ obj-$(CONFIG_PWM_LPSS)		+= pwm-lpss.o
 obj-$(CONFIG_PWM_LPSS_PCI)	+= pwm-lpss-pci.o
 obj-$(CONFIG_PWM_LPSS_PLATFORM)	+= pwm-lpss-platform.o
 obj-$(CONFIG_PWM_MESON)		+= pwm-meson.o
+obj-$(CONFIG_PWM_MEDIATEK)	+= pwm-mediatek.o
 obj-$(CONFIG_PWM_MTK_DISP)	+= pwm-mtk-disp.o
 obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
 obj-$(CONFIG_PWM_OMAP_DMTIMER)	+= pwm-omap-dmtimer.o

drivers/pwm/pwm-atmel-hlcdc.c

@@ -49,172 +49,181 @@ static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
 	return container_of(chip, struct atmel_hlcdc_pwm, chip);
 }
 
-static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
-				  struct pwm_device *pwm,
-				  int duty_ns, int period_ns)
+static int atmel_hlcdc_pwm_apply(struct pwm_chip *c, struct pwm_device *pwm,
+				 struct pwm_state *state)
 {
 	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
 	struct atmel_hlcdc *hlcdc = chip->hlcdc;
-	struct clk *new_clk = hlcdc->slow_clk;
-	u64 pwmcval = duty_ns * 256;
-	unsigned long clk_freq;
-	u64 clk_period_ns;
-	u32 pwmcfg;
-	int pres;
-
-	if (!chip->errata || !chip->errata->slow_clk_erratum) {
-		clk_freq = clk_get_rate(new_clk);
-		if (!clk_freq)
-			return -EINVAL;
+	unsigned int status;
+	int ret;
 
-		clk_period_ns = (u64)NSEC_PER_SEC * 256;
-		do_div(clk_period_ns, clk_freq);
-	}
+	if (state->enabled) {
+		struct clk *new_clk = hlcdc->slow_clk;
+		u64 pwmcval = state->duty_cycle * 256;
+		unsigned long clk_freq;
+		u64 clk_period_ns;
+		u32 pwmcfg;
+		int pres;
+
+		if (!chip->errata || !chip->errata->slow_clk_erratum) {
+			clk_freq = clk_get_rate(new_clk);
+			if (!clk_freq)
+				return -EINVAL;
+
+			clk_period_ns = (u64)NSEC_PER_SEC * 256;
+			do_div(clk_period_ns, clk_freq);
+		}
+
+		/* Errata: cannot use slow clk on some IP revisions */
+		if ((chip->errata && chip->errata->slow_clk_erratum) ||
+		    clk_period_ns > state->period) {
+			new_clk = hlcdc->sys_clk;
+			clk_freq = clk_get_rate(new_clk);
+			if (!clk_freq)
+				return -EINVAL;
+
+			clk_period_ns = (u64)NSEC_PER_SEC * 256;
+			do_div(clk_period_ns, clk_freq);
+		}
+
+		for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
+		/* Errata: cannot divide by 1 on some IP revisions */
+			if (!pres && chip->errata &&
+			    chip->errata->div1_clk_erratum)
+				continue;
+
+			if ((clk_period_ns << pres) >= state->period)
+				break;
+		}
 
-	/* Errata: cannot use slow clk on some IP revisions */
-	if ((chip->errata && chip->errata->slow_clk_erratum) ||
-	    clk_period_ns > period_ns) {
-		new_clk = hlcdc->sys_clk;
-		clk_freq = clk_get_rate(new_clk);
-		if (!clk_freq)
+		if (pres > ATMEL_HLCDC_PWMPS_MAX)
 			return -EINVAL;
 
-		clk_period_ns = (u64)NSEC_PER_SEC * 256;
-		do_div(clk_period_ns, clk_freq);
-	}
+		pwmcfg = ATMEL_HLCDC_PWMPS(pres);
 
-	for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
-		/* Errata: cannot divide by 1 on some IP revisions */
-		if (!pres && chip->errata && chip->errata->div1_clk_erratum)
-			continue;
+		if (new_clk != chip->cur_clk) {
+			u32 gencfg = 0;
+			int ret;
 
-		if ((clk_period_ns << pres) >= period_ns)
-			break;
-	}
+			ret = clk_prepare_enable(new_clk);
+			if (ret)
+				return ret;
 
-	if (pres > ATMEL_HLCDC_PWMPS_MAX)
-		return -EINVAL;
+			clk_disable_unprepare(chip->cur_clk);
+			chip->cur_clk = new_clk;
 
-	pwmcfg = ATMEL_HLCDC_PWMPS(pres);
+			if (new_clk == hlcdc->sys_clk)
+				gencfg = ATMEL_HLCDC_CLKPWMSEL;
 
-	if (new_clk != chip->cur_clk) {
-		u32 gencfg = 0;
-		int ret;
+			ret = regmap_update_bits(hlcdc->regmap,
+						 ATMEL_HLCDC_CFG(0),
+						 ATMEL_HLCDC_CLKPWMSEL,
+						 gencfg);
+			if (ret)
+				return ret;
+		}
 
-		ret = clk_prepare_enable(new_clk);
-		if (ret)
-			return ret;
+		do_div(pwmcval, state->period);
 
-		clk_disable_unprepare(chip->cur_clk);
-		chip->cur_clk = new_clk;
+		/*
+		 * The PWM duty cycle is configurable from 0/256 to 255/256 of
+		 * the period cycle. Hence we can't set a duty cycle occupying
+		 * the whole period cycle if we're asked to.
+		 * Set it to 255 if pwmcval is greater than 256.
+		 */
+		if (pwmcval > 255)
+			pwmcval = 255;
 
-		if (new_clk == hlcdc->sys_clk)
-			gencfg = ATMEL_HLCDC_CLKPWMSEL;
+		pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
 
-		ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
-					 ATMEL_HLCDC_CLKPWMSEL, gencfg);
+		if (state->polarity == PWM_POLARITY_NORMAL)
+			pwmcfg |= ATMEL_HLCDC_PWMPOL;
+
+		ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
+					 ATMEL_HLCDC_PWMCVAL_MASK |
+					 ATMEL_HLCDC_PWMPS_MASK |
+					 ATMEL_HLCDC_PWMPOL,
+					 pwmcfg);
 		if (ret)
 			return ret;
-	}
 
-	do_div(pwmcval, period_ns);
-
-	/*
-	 * The PWM duty cycle is configurable from 0/256 to 255/256 of the
-	 * period cycle. Hence we can't set a duty cycle occupying the
-	 * whole period cycle if we're asked to.
-	 * Set it to 255 if pwmcval is greater than 256.
-	 */
-	if (pwmcval > 255)
-		pwmcval = 255;
-
-	pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
+		ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN,
+				   ATMEL_HLCDC_PWM);
+		if (ret)
+			return ret;
 
-	return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
-				  ATMEL_HLCDC_PWMCVAL_MASK |
-				  ATMEL_HLCDC_PWMPS_MASK,
-				  pwmcfg);
-}
+		ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
+					       status,
+					       status & ATMEL_HLCDC_PWM,
+					       10, 0);
+		if (ret)
+			return ret;
+	} else {
+		ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS,
+				   ATMEL_HLCDC_PWM);
+		if (ret)
+			return ret;
 
-static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
-					struct pwm_device *pwm,
-					enum pwm_polarity polarity)
-{
-	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
-	struct atmel_hlcdc *hlcdc = chip->hlcdc;
-	u32 cfg = 0;
+		ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
+					       status,
+					       !(status & ATMEL_HLCDC_PWM),
+					       10, 0);
+		if (ret)
+			return ret;
 
-	if (polarity == PWM_POLARITY_NORMAL)
-		cfg = ATMEL_HLCDC_PWMPOL;
+		clk_disable_unprepare(chip->cur_clk);
+		chip->cur_clk = NULL;
+	}
 
-	return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
-				  ATMEL_HLCDC_PWMPOL, cfg);
+	return 0;
 }
 
-static int atmel_hlcdc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
-{
-	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
-	struct atmel_hlcdc *hlcdc = chip->hlcdc;
-	u32 status;
-	int ret;
+static const struct pwm_ops atmel_hlcdc_pwm_ops = {
+	.apply = atmel_hlcdc_pwm_apply,
+	.owner = THIS_MODULE,
+};
 
-	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
-	if (ret)
-		return ret;
+static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
+	.slow_clk_erratum = true,
+};
 
-	while (true) {
-		ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
-		if (ret)
-			return ret;
+static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
+	.div1_clk_erratum = true,
+};
 
-		if ((status & ATMEL_HLCDC_PWM) != 0)
-			break;
+#ifdef CONFIG_PM_SLEEP
+static int atmel_hlcdc_pwm_suspend(struct device *dev)
+{
+	struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
 
-		usleep_range(1, 10);
-	}
+	/* Keep the periph clock enabled if the PWM is still running. */
+	if (pwm_is_enabled(&chip->chip.pwms[0]))
+		clk_disable_unprepare(chip->hlcdc->periph_clk);
 
 	return 0;
 }
 
-static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
-				    struct pwm_device *pwm)
+static int atmel_hlcdc_pwm_resume(struct device *dev)
 {
-	struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
-	struct atmel_hlcdc *hlcdc = chip->hlcdc;
-	u32 status;
+	struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
+	struct pwm_state state;
 	int ret;
 
-	ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
-	if (ret)
-		return;
+	pwm_get_state(&chip->chip.pwms[0], &state);
 
-	while (true) {
-		ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
+	/* Re-enable the periph clock it was stopped during suspend. */
+	if (!state.enabled) {
+		ret = clk_prepare_enable(chip->hlcdc->periph_clk);
 		if (ret)
-			return;
-
-		if ((status & ATMEL_HLCDC_PWM) == 0)
-			break;
-
-		usleep_range(1, 10);
+			return ret;
 	}
-}
-
-static const struct pwm_ops atmel_hlcdc_pwm_ops = {
-	.config = atmel_hlcdc_pwm_config,
-	.set_polarity = atmel_hlcdc_pwm_set_polarity,
-	.enable = atmel_hlcdc_pwm_enable,
-	.disable = atmel_hlcdc_pwm_disable,
-	.owner = THIS_MODULE,
-};
 
-static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
-	.slow_clk_erratum = true,
-};
+	return atmel_hlcdc_pwm_apply(&chip->chip, &chip->chip.pwms[0], &state);
+}
+#endif
 
-static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
-	.div1_clk_erratum = true,
-};
+static SIMPLE_DEV_PM_OPS(atmel_hlcdc_pwm_pm_ops,
+			 atmel_hlcdc_pwm_suspend, atmel_hlcdc_pwm_resume);
 
 static const struct of_device_id atmel_hlcdc_dt_ids[] = {
 	{
@@ -305,6 +314,7 @@ static struct platform_driver atmel_hlcdc_pwm_driver = {
 	.driver = {
 		.name = "atmel-hlcdc-pwm",
 		.of_match_table = atmel_hlcdc_pwm_dt_ids,
+		.pm = &atmel_hlcdc_pwm_pm_ops,
 	},
 	.probe = atmel_hlcdc_pwm_probe,
 	.remove = atmel_hlcdc_pwm_remove,

drivers/pwm/pwm-mediatek.c

+/*
+ * Mediatek Pulse Width Modulator driver
+ *
+ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+/* PWM registers and bits definitions */
+#define PWMCON			0x00
+#define PWMHDUR			0x04
+#define PWMLDUR			0x08
+#define PWMGDUR			0x0c
+#define PWMWAVENUM		0x28
+#define PWMDWIDTH		0x2c
+#define PWMTHRES		0x30
+
+enum {
+	MTK_CLK_MAIN = 0,
+	MTK_CLK_TOP,
+	MTK_CLK_PWM1,
+	MTK_CLK_PWM2,
+	MTK_CLK_PWM3,
+	MTK_CLK_PWM4,
+	MTK_CLK_PWM5,
+	MTK_CLK_MAX,
+};
+
+static const char * const mtk_pwm_clk_name[] = {
+	"main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5"
+};
+
+/**
+ * struct mtk_pwm_chip - struct representing PWM chip
+ * @chip: linux PWM chip representation
+ * @regs: base address of PWM chip
+ * @clks: list of clocks
+ */
+struct mtk_pwm_chip {
+	struct pwm_chip chip;
+	void __iomem *regs;
+	struct clk *clks[MTK_CLK_MAX];
+};
+
+static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct mtk_pwm_chip, chip);
+}
+
+static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
+				unsigned int offset)
+{
+	return readl(chip->regs + 0x10 + (num * 0x40) + offset);
+}
+
+static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
+				  unsigned int num, unsigned int offset,
+				  u32 value)
+{
+	writel(value, chip->regs + 0x10 + (num * 0x40) + offset);
+}
+
+static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			  int duty_ns, int period_ns)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm];
+	u32 resolution, clkdiv = 0;
+
+	resolution = NSEC_PER_SEC / clk_get_rate(clk);
+
+	while (period_ns / resolution > 8191) {
+		resolution *= 2;
+		clkdiv++;
+	}
+
+	if (clkdiv > 7)
+		return -EINVAL;
+
+	mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv);
+	mtk_pwm_writel(pc, pwm->hwpwm, PWMDWIDTH, period_ns / resolution);
+	mtk_pwm_writel(pc, pwm->hwpwm, PWMTHRES, duty_ns / resolution);
+
+	return 0;
+}
+
+static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	u32 value;
+	int ret;
+
+	ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+	if (ret < 0)
+		return ret;
+
+	value = readl(pc->regs);
+	value |= BIT(pwm->hwpwm);
+	writel(value, pc->regs);
+
+	return 0;
+}
+
+static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+	u32 value;
+
+	value = readl(pc->regs);
+	value &= ~BIT(pwm->hwpwm);
+	writel(value, pc->regs);
+
+	clk_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+}
+
+static const struct pwm_ops mtk_pwm_ops = {
+	.config = mtk_pwm_config,
+	.enable = mtk_pwm_enable,
+	.disable = mtk_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int mtk_pwm_probe(struct platform_device *pdev)
+{
+	struct mtk_pwm_chip *pc;
+	struct resource *res;
+	unsigned int i;
+	int ret;
+
+	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pc->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pc->regs))
+		return PTR_ERR(pc->regs);
+
+	for (i = 0; i < MTK_CLK_MAX; i++) {
+		pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]);
+		if (IS_ERR(pc->clks[i]))
+			return PTR_ERR(pc->clks[i]);
+	}
+
+	ret = clk_prepare(pc->clks[MTK_CLK_TOP]);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_prepare(pc->clks[MTK_CLK_MAIN]);
+	if (ret < 0)
+		goto disable_clk_top;
+
+	platform_set_drvdata(pdev, pc);
+
+	pc->chip.dev = &pdev->dev;
+	pc->chip.ops = &mtk_pwm_ops;
+	pc->chip.base = -1;
+	pc->chip.npwm = 5;
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+		goto disable_clk_main;
+	}
+
+	return 0;
+
+disable_clk_main:
+	clk_unprepare(pc->clks[MTK_CLK_MAIN]);
+disable_clk_top:
+	clk_unprepare(pc->clks[MTK_CLK_TOP]);
+
+	return ret;
+}
+
+static int mtk_pwm_remove(struct platform_device *pdev)
+{
+	struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < pc->chip.npwm; i++)
+		pwm_disable(&pc->chip.pwms[i]);
+
+	return pwmchip_remove(&pc->chip);
+}
+
+static const struct of_device_id mtk_pwm_of_match[] = {
+	{ .compatible = "mediatek,mt7623-pwm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mtk_pwm_of_match);
+
+static struct platform_driver mtk_pwm_driver = {
+	.driver = {
+		.name = "mtk-pwm",
+		.of_match_table = mtk_pwm_of_match,
+	},
+	.probe = mtk_pwm_probe,
+	.remove = mtk_pwm_remove,
+};
+module_platform_driver(mtk_pwm_driver);
+
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_ALIAS("platform:mtk-pwm");
+MODULE_LICENSE("GPL");

drivers/pwm/pwm-pca9685.c

@@ -30,6 +30,7 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/pm_runtime.h>
 
 /*
  * Because the PCA9685 has only one prescaler per chip, changing the period of
@@ -79,7 +80,6 @@
 struct pca9685 {
 	struct pwm_chip chip;
 	struct regmap *regmap;
-	int active_cnt;
 	int duty_ns;
 	int period_ns;
 #if IS_ENABLED(CONFIG_GPIOLIB)
@@ -111,20 +111,10 @@ static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
 	pwm_set_chip_data(pwm, (void *)1);
 
 	mutex_unlock(&pca->lock);
+	pm_runtime_get_sync(pca->chip.dev);
 	return 0;
 }
 
-static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
-{
-	struct pca9685 *pca = gpiochip_get_data(gpio);
-	struct pwm_device *pwm;
-
-	mutex_lock(&pca->lock);
-	pwm = &pca->chip.pwms[offset];
-	pwm_set_chip_data(pwm, NULL);
-	mutex_unlock(&pca->lock);
-}
-
 static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
 {
 	bool is_gpio = false;
@@ -177,6 +167,19 @@ static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
 	regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
 }
 
+static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm;
+
+	pca9685_pwm_gpio_set(gpio, offset, 0);
+	pm_runtime_put(pca->chip.dev);
+	mutex_lock(&pca->lock);
+	pwm = &pca->chip.pwms[offset];
+	pwm_set_chip_data(pwm, NULL);
+	mutex_unlock(&pca->lock);
+}
+
 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
 					  unsigned int offset)
 {
@@ -238,6 +241,16 @@ static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
 }
 #endif
 
+static void pca9685_set_sleep_mode(struct pca9685 *pca, int sleep)
+{
+	regmap_update_bits(pca->regmap, PCA9685_MODE1,
+			   MODE1_SLEEP, sleep ? MODE1_SLEEP : 0);
+	if (!sleep) {
+		/* Wait 500us for the oscillator to be back up */
+		udelay(500);
+	}
+}
+
 static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
@@ -252,19 +265,20 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 
 		if (prescale >= PCA9685_PRESCALE_MIN &&
 			prescale <= PCA9685_PRESCALE_MAX) {
+			/*
+			 * putting the chip briefly into SLEEP mode
+			 * at this point won't interfere with the
+			 * pm_runtime framework, because the pm_runtime
+			 * state is guaranteed active here.
+			 */
 			/* Put chip into sleep mode */
-			regmap_update_bits(pca->regmap, PCA9685_MODE1,
-					   MODE1_SLEEP, MODE1_SLEEP);
+			pca9685_set_sleep_mode(pca, 1);
 
 			/* Change the chip-wide output frequency */
 			regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
 
 			/* Wake the chip up */
-			regmap_update_bits(pca->regmap, PCA9685_MODE1,
-					   MODE1_SLEEP, 0x0);
-
-			/* Wait 500us for the oscillator to be back up */
-			udelay(500);
+			pca9685_set_sleep_mode(pca, 0);
 
 			pca->period_ns = period_ns;
 		} else {
@@ -406,21 +420,15 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	if (pca9685_pwm_is_gpio(pca, pwm))
 		return -EBUSY;
-
-	if (pca->active_cnt++ == 0)
-		return regmap_update_bits(pca->regmap, PCA9685_MODE1,
-					  MODE1_SLEEP, 0x0);
+	pm_runtime_get_sync(chip->dev);
 
 	return 0;
 }
 
 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct pca9685 *pca = to_pca(chip);
-
-	if (--pca->active_cnt == 0)
-		regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
-				   MODE1_SLEEP);
+	pca9685_pwm_disable(chip, pwm);
+	pm_runtime_put(chip->dev);
 }
 
 static const struct pwm_ops pca9685_pwm_ops = {
@@ -492,22 +500,54 @@ static int pca9685_pwm_probe(struct i2c_client *client,
 		return ret;
 
 	ret = pca9685_pwm_gpio_probe(pca);
-	if (ret < 0)
+	if (ret < 0) {
 		pwmchip_remove(&pca->chip);
+		return ret;
+	}
+
+	/* the chip comes out of power-up in the active state */
+	pm_runtime_set_active(&client->dev);
+	/*
+	 * enable will put the chip into suspend, which is what we
+	 * want as all outputs are disabled at this point
+	 */
+	pm_runtime_enable(&client->dev);
 
-	return ret;
+	return 0;
 }
 
 static int pca9685_pwm_remove(struct i2c_client *client)
 {
 	struct pca9685 *pca = i2c_get_clientdata(client);
+	int ret;
 
-	regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
-			   MODE1_SLEEP);
+	ret = pwmchip_remove(&pca->chip);
+	if (ret)
+		return ret;
+	pm_runtime_disable(&client->dev);
+	return 0;
+}
 
-	return pwmchip_remove(&pca->chip);
+#ifdef CONFIG_PM
+static int pca9685_pwm_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct pca9685 *pca = i2c_get_clientdata(client);
+
+	pca9685_set_sleep_mode(pca, 1);
+	return 0;
 }
 
+static int pca9685_pwm_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct pca9685 *pca = i2c_get_clientdata(client);
+
+	pca9685_set_sleep_mode(pca, 0);
+	return 0;
+}
+#endif
+
 static const struct i2c_device_id pca9685_id[] = {
 	{ "pca9685", 0 },
 	{ /* sentinel */ },
@@ -530,11 +570,17 @@ static const struct of_device_id pca9685_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
 #endif
 
+static const struct dev_pm_ops pca9685_pwm_pm = {
+	SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
+			   pca9685_pwm_runtime_resume, NULL)
+};
+
 static struct i2c_driver pca9685_i2c_driver = {
 	.driver = {
 		.name = "pca9685-pwm",
 		.acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
 		.of_match_table = of_match_ptr(pca9685_dt_ids),
+		.pm = &pca9685_pwm_pm,
 	},
 	.probe = pca9685_pwm_probe,
 	.remove = pca9685_pwm_remove,

drivers/pwm/pwm-tegra.c

@@ -29,6 +29,7 @@
 #include <linux/of_device.h>
 #include <linux/pwm.h>
 #include <linux/platform_device.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/slab.h>
 #include <linux/reset.h>
 
@@ -49,6 +50,8 @@ struct tegra_pwm_chip {
 	struct clk *clk;
 	struct reset_control*rst;
 
+	unsigned long clk_rate;
+
 	void __iomem *regs;
 
 	const struct tegra_pwm_soc *soc;
@@ -74,8 +77,8 @@ static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			    int duty_ns, int period_ns)
 {
 	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
-	unsigned long long c = duty_ns;
-	unsigned long rate, hz;
+	unsigned long long c = duty_ns, hz;
+	unsigned long rate;
 	u32 val = 0;
 	int err;
 
@@ -85,8 +88,7 @@ static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * nearest integer during division.
 	 */
 	c *= (1 << PWM_DUTY_WIDTH);
-	c += period_ns / 2;
-	do_div(c, period_ns);
+	c = DIV_ROUND_CLOSEST_ULL(c, period_ns);
 
 	val = (u32)c << PWM_DUTY_SHIFT;
 
@@ -94,10 +96,11 @@ static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * Compute the prescaler value for which (1 << PWM_DUTY_WIDTH)
 	 * cycles at the PWM clock rate will take period_ns nanoseconds.
 	 */
-	rate = clk_get_rate(pc->clk) >> PWM_DUTY_WIDTH;
-	hz = NSEC_PER_SEC / period_ns;
+	rate = pc->clk_rate >> PWM_DUTY_WIDTH;
 
-	rate = (rate + (hz / 2)) / hz;
+	/* Consider precision in PWM_SCALE_WIDTH rate calculation */
+	hz = DIV_ROUND_CLOSEST_ULL(100ULL * NSEC_PER_SEC, period_ns);
+	rate = DIV_ROUND_CLOSEST_ULL(100ULL * rate, hz);
 
 	/*
 	 * Since the actual PWM divider is the register's frequency divider
@@ -198,6 +201,9 @@ static int tegra_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pwm->clk))
 		return PTR_ERR(pwm->clk);
 
+	/* Read PWM clock rate from source */
+	pwm->clk_rate = clk_get_rate(pwm->clk);
+
 	pwm->rst = devm_reset_control_get(&pdev->dev, "pwm");
 	if (IS_ERR(pwm->rst)) {
 		ret = PTR_ERR(pwm->rst);
@@ -253,6 +259,18 @@ static int tegra_pwm_remove(struct platform_device *pdev)
 	return pwmchip_remove(&pc->chip);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int tegra_pwm_suspend(struct device *dev)
+{
+	return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int tegra_pwm_resume(struct device *dev)
+{
+	return pinctrl_pm_select_default_state(dev);
+}
+#endif
+
 static const struct tegra_pwm_soc tegra20_pwm_soc = {
 	.num_channels = 4,
 };
@@ -269,10 +287,15 @@ static const struct of_device_id tegra_pwm_of_match[] = {
 
 MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
 
+static const struct dev_pm_ops tegra_pwm_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tegra_pwm_suspend, tegra_pwm_resume)
+};
+
 static struct platform_driver tegra_pwm_driver = {
 	.driver = {
 		.name = "tegra-pwm",
 		.of_match_table = tegra_pwm_of_match,
+		.pm = &tegra_pwm_pm_ops,
 	},
 	.probe = tegra_pwm_probe,
 	.remove = tegra_pwm_remove,