pwm: add support for atomic update

@@ -157,7 +157,7 @@ static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return div;
 
 	/* Let the core driver set pwm->period if disabled and duty_ns = 0 */
-	if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns)
+	if (!pwm_is_enabled(pwm) && !duty_ns)
 		return 0;
 
 	rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR);

@@ -313,10 +313,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	 * via the PWM lookup table.
 	 */
 	pb->period = pwm_get_period(pb->pwm);
-	if (!pb->period && (data->pwm_period_ns > 0)) {
+	if (!pb->period && (data->pwm_period_ns > 0))
 		pb->period = data->pwm_period_ns;
-		pwm_set_period(pb->pwm, data->pwm_period_ns);
-	}
 
 	pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);
 

@@ -56,6 +56,7 @@ static const struct clk_ops clk_pwm_ops = {
 static int clk_pwm_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
+	struct pwm_args pargs = { };
 	struct clk_init_data init;
 	struct clk_pwm *clk_pwm;
 	struct pwm_device *pwm;

@@ -71,22 +72,23 @@ static int clk_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pwm))
 		return PTR_ERR(pwm);
 
-	if (!pwm->period) {
+	pwm_get_args(pwm, &pargs);
+	if (!pargs.period) {
 		dev_err(&pdev->dev, "invalid PWM period\n");
 		return -EINVAL;
 	}
 
 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
-		clk_pwm->fixed_rate = NSEC_PER_SEC / pwm->period;
+		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
 
-	if (pwm->period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
-	    pwm->period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
+	if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
+	    pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
 		dev_err(&pdev->dev,
 			"clock-frequency does not match PWM period\n");
 		return -EINVAL;
 	}
 
-	ret = pwm_config(pwm, (pwm->period + 1) >> 1, pwm->period);
+	ret = pwm_config(pwm, (pargs.period + 1) >> 1, pargs.period);
 	if (ret < 0)
 		return ret;
 

@@ -40,15 +40,18 @@ struct pwm_fan_ctx {
 
 static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
+	struct pwm_args pargs = { };
 	unsigned long duty;
 	int ret = 0;
 
+	pwm_get_args(ctx->pwm, &pargs);
+
 	mutex_lock(&ctx->lock);
 	if (ctx->pwm_value = pwm)
 		goto exit_set_pwm_err;
 
-	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+	duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, pargs.period);
 	if (ret)
 		goto exit_set_pwm_err;
 

@@ -214,6 +217,7 @@ static int pwm_fan_of_get_cooling_data(struct device *dev,
 static int pwm_fan_probe(struct platform_device *pdev)
 {
 	struct thermal_cooling_device *cdev;
+	struct pwm_args pargs = { };
 	struct pwm_fan_ctx *ctx;
 	struct device *hwmon;
 	int duty_cycle;

@@ -234,10 +238,11 @@ static int pwm_fan_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, ctx);
 
 	/* Set duty cycle to maximum allowed */
-	duty_cycle = ctx->pwm->period - 1;
+	pwm_get_args(ctx->pwm, &pargs);
+	duty_cycle = pargs.period - 1;
 	ctx->pwm_value = MAX_PWM;
 
-	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
+	ret = pwm_config(ctx->pwm, duty_cycle, pargs.period);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to configure PWM\n");
 		return ret;

@@ -303,14 +308,16 @@ static int pwm_fan_suspend(struct device *dev)
 static int pwm_fan_resume(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+	struct pwm_args pargs = { };
 	unsigned long duty;
 	int ret;
 
 	if (ctx->pwm_value = 0)
 		return 0;
 
-	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+	pwm_get_args(ctx->pwm, &pargs);
+	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, pargs.period);
 	if (ret)
 		return ret;
 	return pwm_enable(ctx->pwm);

@@ -286,6 +286,7 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 {
 	int ret;
 	u32 precharge, dclk, com_invdir, compins;
+	struct pwm_args pargs = { };
 
 	if (par->device_info->need_pwm) {
 		par->pwm = pwm_get(&par->client->dev, NULL);

@@ -294,7 +295,8 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 			return PTR_ERR(par->pwm);
 		}
 
-		par->pwm_period = pwm_get_period(par->pwm);
+		pwm_get_args(par->pwm, &pargs);
+		par->pwm_period = pargs.period;
 		/* Enable the PWM */
 		pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
 		pwm_enable(par->pwm);

@@ -147,13 +147,11 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
 		return pwm;
 
 	pwm->args.period = args->args[1];
-	pwm_set_period(pwm, pwm->args.period);
 
 	if (args->args[2] & PWM_POLARITY_INVERTED)
 		pwm->args.polarity = PWM_POLARITY_INVERSED;
 	else
 		pwm->args.polarity = PWM_POLARITY_NORMAL;
-	pwm_set_polarity(pwm, pwm->args.polarity);
 
 	return pwm;
 }

@@ -175,7 +173,6 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 		return pwm;
 
 	pwm->args.period = args->args[1];
-	pwm_set_period(pwm, pwm->args.period);
 
 	return pwm;
 }

@@ -745,8 +742,6 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
 
 	pwm->args.period = chosen->period;
 	pwm->args.polarity = chosen->polarity;
-	pwm_set_period(pwm, chosen->period);
-	pwm_set_polarity(pwm, chosen->polarity);
 
 out:
 	mutex_unlock(&pwm_lookup_lock);

@@ -61,7 +61,6 @@ static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	/* Store constant period value */
 	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
-	pwm_set_period(pwm, pwm->args.period);
 
 	return 0;
 }

@@ -161,7 +161,6 @@ pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 		return pwm;
 
 	pwm->args.period = args->args[0];
-	pwm_set_period(pwm, args->args[0]);
 
 	return pwm;
 }

@@ -270,6 +270,9 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm->hwpwm = i;
 		pwm->state.polarity = polarity;
 
+		if (chip->ops->get_state)
+			chip->ops->get_state(chip, pwm, &pwm->state);
+
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
 

@@ -211,6 +211,9 @@ static inline void pwm_get_args(const struct pwm_device *pwm,
  * @set_polarity: configure the polarity of this PWM
  * @enable: enable PWM output toggling
  * @disable: disable PWM output toggling
+ * @get_state: get the current PWM state. This function is only
+ *	       called once per PWM device when the PWM chip is
+ *	       registered.
  * @dbg_show: optional routine to show contents in debugfs
  * @owner: helps prevent removal of modules exporting active PWMs
  */

@@ -223,6 +226,8 @@ struct pwm_ops {
 			    enum pwm_polarity polarity);
 	int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
 	void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
+	void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
+			  struct pwm_state *pstate);
 #ifdef CONFIG_DEBUG_FS
 	void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
 #endif

@@ -894,6 +894,11 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 		if (pstate.enabled)
 			seq_puts(s, " enabled");
 
+		seq_printf(s, " period:%uns", pstate.period);
+		seq_printf(s, " duty:%uns", pstate.duty_cycle);
+		seq_printf(s, " polarity:%s",
+			   pstate.polarity ? "inverse" : "normal");
+
 		seq_puts(s, "\n");
 	}
 }

@@ -302,6 +302,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *id;
 	struct rockchip_pwm_chip *pc;
+	struct pwm_state pstate;
 	struct resource *r;
 	int ret;
 

@@ -322,7 +323,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pc->clk))
 		return PTR_ERR(pc->clk);
 
-	ret = clk_prepare(pc->clk);
+	ret = clk_prepare_enable(pc->clk);
 	if (ret)
 		return ret;
 

@@ -345,12 +346,33 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 	}
 
+	/* Keep the PWM clk enabled if the PWM appears to be up and running. */
+	pwm_get_state(pc->chip.pwms, &pstate);
+	if (!pstate.enabled)
+		clk_disable(pc->clk);
+
 	return ret;
 }
 
 static int rockchip_pwm_remove(struct platform_device *pdev)
 {
 	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
+	struct pwm_state pstate;
+
+	/*
+	 * Disable the PWM clk before unpreparing it if the PWM device is still
+	 * running. This should only happen when the last PWM user left it
+	 * enabled, or when nobody requested a PWM that was previously enabled
+	 * by the bootloader.
+	 *
+	 * FIXME: Maybe the core should disable all PWM devices in
+	 * pwmchip_remove(). In this case we'd only have to call
+	 * clk_unprepare() after pwmchip_remove().
+	 *
+	 */
+	pwm_get_state(pc->chip.pwms, &pstate);
+	if (pstate.enabled)
+		clk_disable(pc->clk);
 
 	clk_unprepare(pc->clk);
 

@@ -343,7 +343,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	struct sti_pwm_compat_data *cdata;
 	struct sti_pwm_chip *pc;
 	struct resource *res;
-	int ret;
+	int i, ret;
 
 	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)

@@ -394,7 +394,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	ret = clk_prepare(pc->clk);
+	ret = clk_prepare_enable(pc->clk);
 	if (ret) {
 		dev_err(dev, "failed to prepare clock\n");
 		return ret;

@@ -412,6 +412,19 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	/*
+	 * Keep the PWM clk enabled if some PWMs appear to be up and
+	 * running.
+	 */
+	for (i = 0; i < pc->chip.npwm; i++) {
+		struct pwm_state pstate;
+
+		pwm_get_state(&pc->chip.pwms[i], &pstate);
+		if (pstate.enabled)
+			clk_enable(pc->clk);
+	}
+	clk_disable(pc->clk);
+
 	platform_set_drvdata(pdev, pc);
 
 	return 0;

@@ -252,11 +252,65 @@ static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	clk_disable_unprepare(sun4i_pwm->clk);
 }
 
+static void sun4i_pwm_get_state(struct pwm_chip *chip,
+				struct pwm_device *pwm,
+				struct pwm_state *pstate)
+{
+	struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
+	unsigned int clk_rate = clk_get_rate(sun4i_pwm->clk);
+	int prescaler, prescalerid;
+	int ret;
+	u32 val;
+
+	ret = clk_prepare_enable(sun4i_pwm->clk);
+	if (ret) {
+		dev_err(chip->dev, "Failed to enable PWM clock");
+		return;
+	}
+
+	val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
+	if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm))
+		pstate->polarity = PWM_POLARITY_INVERSED;
+	else
+		pstate->polarity = PWM_POLARITY_NORMAL;
+
+	if ((val & BIT_CH(PWM_EN, pwm->hwpwm)) &&
+	    (val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm)))
+		pstate->enabled = true;
+	else
+		pstate->enabled = false;
+
+	pstate->period = 0;
+	pstate->duty_cycle = 0;
+	prescalerid = (val >> (PWMCH_OFFSET * pwm->hwpwm)) & PWM_PRESCAL_MASK;
+	prescaler = prescaler_table[prescalerid];
+	if (prescaler) {
+		u64 timens;
+
+		clk_rate /= prescaler;
+
+		val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm));
+
+		timens = ((val >> 16) & PWM_PRD_MASK) + 1;
+		timens *= NSEC_PER_SEC;
+		do_div(timens, clk_rate);
+		pstate->period = timens;
+
+		timens = val & PWM_DTY_MASK;
+		timens *= NSEC_PER_SEC;
+		do_div(timens, clk_rate);
+		pstate->duty_cycle = timens;
+	}
+
+	clk_disable_unprepare(sun4i_pwm->clk);
+}
+
 static const struct pwm_ops sun4i_pwm_ops = {
 	.config = sun4i_pwm_config,
 	.set_polarity = sun4i_pwm_set_polarity,
 	.enable = sun4i_pwm_enable,
 	.disable = sun4i_pwm_disable,
+	.get_state = sun4i_pwm_get_state,
 	.owner = THIS_MODULE,
 };
 

@@ -307,8 +361,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 {
 	struct sun4i_pwm_chip *pwm;
 	struct resource *res;
-	u32 val;
-	int i, ret;
+	int ret;
 	const struct of_device_id *match;
 
 	match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);

@@ -345,24 +398,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, pwm);
 
-	ret = clk_prepare_enable(pwm->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to enable PWM clock\n");
-		goto clk_error;
-	}
-
-	val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
-	for (i = 0; i < pwm->chip.npwm; i++)
-		if (!(val & BIT_CH(PWM_ACT_STATE, i)))
-			pwm_set_polarity(&pwm->chip.pwms[i],
-					 PWM_POLARITY_INVERSED);
-	clk_disable_unprepare(pwm->clk);
-
 	return 0;
-
-clk_error:
-	pwmchip_remove(&pwm->chip);
-	return ret;
 }
 
 static int sun4i_pwm_remove(struct platform_device *pdev)

@@ -35,9 +35,6 @@ struct pwm_regulator_data {
 	struct regulator_ops ops;
 
 	int state;
-
-	/* Continuous voltage */
-	int volt_uV;
 };
 
 struct pwm_voltages {

@@ -167,11 +164,27 @@ static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int
 	return ((req_uV * 100) - (min_uV * 100)) / diff;
 }
 
+static int pwm_duty_cycle_percentage_to_voltage(struct regulator_dev *rdev,
+						int dutycycle)
+{
+	int min_uV = rdev->constraints->min_uV;
+	int max_uV = rdev->constraints->max_uV;
+	int diff = max_uV - min_uV;
+
+	return min_uV + ((diff * dutycycle) / 100);
+}
+
 static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pstate;
+	u64 dutycycle;
 
-	return drvdata->volt_uV;
+	pwm_get_state(drvdata->pwm, &pstate);
+	dutycycle = pstate.duty_cycle * 100;
+	do_div(dutycycle, pstate.period);
+
+	return pwm_duty_cycle_percentage_to_voltage(rdev, dutycycle);
 }
 
 static int pwm_regulator_set_voltage(struct regulator_dev *rdev,

@@ -196,8 +209,6 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
 		return ret;
 	}
 
-	drvdata->volt_uV = min_uV;
-
 	/* Delay required by PWM regulator to settle to the new voltage */
 	usleep_range(ramp_delay, ramp_delay + 1000);
 

@@ -40,8 +40,8 @@ struct pwm_fan_ctx {
 
 static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
+	struct pwm_state pstate;
 	struct pwm_args pargs = { };
-	unsigned long duty;
 	int ret = 0;
 
 	pwm_get_args(ctx->pwm, &pargs);

@@ -50,19 +50,17 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 	if (ctx->pwm_value = pwm)
 		goto exit_set_pwm_err;
 
-	duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, pargs.period);
-	if (ret)
-		goto exit_set_pwm_err;
-
+	pwm_get_state(ctx->pwm, &pstate);
+	pstate.period = pargs.period;
+	pstate.duty_cycle = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
 	if (pwm = 0)
-		pwm_disable(ctx->pwm);
+		pstate.enabled = false;
+	else
+		pstate.enabled = true;
 
-	if (ctx->pwm_value = 0) {
-		ret = pwm_enable(ctx->pwm);
-		if (ret)
-			goto exit_set_pwm_err;
-	}
+	ret = pwm_apply_state(ctx->pwm, &pstate);
+	if (ret)
+		goto exit_set_pwm_err;
 
 	ctx->pwm_value = pwm;
 exit_set_pwm_err:

@@ -217,10 +215,10 @@ static int pwm_fan_of_get_cooling_data(struct device *dev,
 static int pwm_fan_probe(struct platform_device *pdev)
 {
 	struct thermal_cooling_device *cdev;
+	struct pwm_state pstate;
 	struct pwm_args pargs = { };
 	struct pwm_fan_ctx *ctx;
 	struct device *hwmon;
-	int duty_cycle;
 	int ret;
 
 	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);

@@ -239,27 +237,25 @@ static int pwm_fan_probe(struct platform_device *pdev)
 
 	/* Set duty cycle to maximum allowed */
 	pwm_get_args(ctx->pwm, &pargs);
-	duty_cycle = pargs.period - 1;
+	pwm_get_state(ctx->pwm, &pstate);
+
+	pstate.period = pargs.period;
+	pstate.duty_cycle = pargs.period - 1;
+	pstate.enabled = true;
 	ctx->pwm_value = MAX_PWM;
 
-	ret = pwm_config(ctx->pwm, duty_cycle, pargs.period);
+	ret = pwm_apply_state(ctx->pwm, &pstate);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to configure PWM\n");
 		return ret;
 	}
 
-	/* Enbale PWM output */
-	ret = pwm_enable(ctx->pwm);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to enable PWM\n");
-		return ret;
-	}
-
 	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
 						       ctx, pwm_fan_groups);
 	if (IS_ERR(hwmon)) {
 		dev_err(&pdev->dev, "Failed to register hwmon device\n");
-		pwm_disable(ctx->pwm);
+		pstate.enabled = false;
+		pwm_apply_state(ctx->pwm, &pstate);
 		return PTR_ERR(hwmon);
 	}
 

@@ -275,7 +271,8 @@ static int pwm_fan_probe(struct platform_device *pdev)
 		if (IS_ERR(cdev)) {
 			dev_err(&pdev->dev,
 				"Failed to register pwm-fan as cooling device");
-			pwm_disable(ctx->pwm);
+			pstate.enabled = false;
+			pwm_apply_state(ctx->pwm, &pstate);
 			return PTR_ERR(cdev);
 		}
 		ctx->cdev = cdev;

@@ -290,8 +287,14 @@ static int pwm_fan_remove(struct platform_device *pdev)
 	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
 
 	thermal_cooling_device_unregister(ctx->cdev);
-	if (ctx->pwm_value)
-		pwm_disable(ctx->pwm);
+	if (ctx->pwm_value) {
+		struct pwm_state pstate;
+
+		pwm_get_state(ctx->pwm, &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(ctx->pwm, &pstate);
+	}
+
 	return 0;
 }
 

@@ -300,27 +303,35 @@ static int pwm_fan_suspend(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
-	if (ctx->pwm_value)
-		pwm_disable(ctx->pwm);
+	if (ctx->pwm_value) {
+		struct pwm_state pstate;
+
+		pwm_get_state(ctx->pwm, &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(ctx->pwm, &pstate);
+	}
+
 	return 0;
 }
 
 static int pwm_fan_resume(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+	struct pwm_state pstate;
 	struct pwm_args pargs = { };
-	unsigned long duty;
-	int ret;
 
 	if (ctx->pwm_value = 0)
 		return 0;
 
 	pwm_get_args(ctx->pwm, &pargs);
-	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, pargs.period);
-	if (ret)
-		return ret;
-	return pwm_enable(ctx->pwm);
+	pwm_get_state(ctx->pwm, &pstate);
+
+	pstate.period = pargs.period;
+	pstate.duty_cycle = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1),
+					 MAX_PWM);
+	pstate.enabled = true;
+
+	return pwm_apply_state(ctx->pwm, &pstate);
 }
 #endif
 

@@ -70,13 +70,16 @@ struct max77693_haptic {
 
 static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
 {
+	struct pwm_state pstate;
 	struct pwm_args pargs = { };
-	int delta;
 	int error;
 
 	pwm_get_args(haptic->pwm_dev, &pargs);
-	delta = (pargs.period + haptic->pwm_duty) / 2;
-	error = pwm_config(haptic->pwm_dev, delta, pargs.period);
+	pwm_get_state(haptic->pwm_dev, &pstate);
+
+	pstate.period = pargs.period;
+	pstate.duty_cycle = (pargs.period + haptic->pwm_duty) / 2;
+	error = pwm_apply_state(haptic->pwm_dev, &pstate);
 	if (error) {
 		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
 		return error;

@@ -161,12 +164,16 @@ static int max77693_haptic_lowsys(struct max77693_haptic *haptic, bool enable)
 
 static void max77693_haptic_enable(struct max77693_haptic *haptic)
 {
+	struct pwm_state pstate;
 	int error;
 
 	if (haptic->enabled)
 		return;
 
-	error = pwm_enable(haptic->pwm_dev);
+	pwm_get_state(haptic->pwm_dev, &pstate);
+	pstate.enabled = true;
+
+	error = pwm_apply_state(haptic->pwm_dev, &pstate);
 	if (error) {
 		dev_err(haptic->dev,
 			"failed to enable haptic pwm device: %d\n", error);

@@ -188,11 +195,13 @@ static void max77693_haptic_enable(struct max77693_haptic *haptic)
 err_enable_config:
 	max77693_haptic_lowsys(haptic, false);
 err_enable_lowsys:
-	pwm_disable(haptic->pwm_dev);
+	pstate.enabled = false;
+	pwm_apply_state(haptic->pwm_dev, &pstate);
 }
 
 static void max77693_haptic_disable(struct max77693_haptic *haptic)
 {
+	struct pwm_state pstate;
 	int error;
 
 	if (!haptic->enabled)

@@ -206,7 +215,9 @@ static void max77693_haptic_disable(struct max77693_haptic *haptic)
 	if (error)
 		goto err_disable_lowsys;
 
-	pwm_disable(haptic->pwm_dev);
+	pwm_get_state(haptic->pwm_dev, &pstate);
+	pstate.enabled = false;
+	pwm_apply_state(haptic->pwm_dev, &pstate);
 	haptic->enabled = false;
 
 	return;

@@ -162,14 +162,16 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 
 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pchip->pdata->pwm_period;
-	unsigned int duty = br * period / br_max;
+	struct pwm_state pstate;
 
-	pwm_config(pchip->pwmd, duty, period);
-	if (duty)
-		pwm_enable(pchip->pwmd);
+	pwm_get_state(pchip->pwmd, &pstate);
+	pstate.period = pchip->pdata->pwm_period;
+	pstate.duty_cycle = br * pstate.period / br_max;
+	if (pstate.duty_cycle)
+		pstate.enabled = true;
 	else
-		pwm_disable(pchip->pwmd);
+		pstate.enabled = false;
+	pwm_apply_state(pchip->pwmd, &pstate);
 }
 
 /* update and get brightness */

@@ -235,8 +235,7 @@ err:
 
 static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
 {
-	unsigned int period = lp->pdata->period_ns;
-	unsigned int duty = br * period / max_br;
+	struct pwm_state pstate;
 	struct pwm_device *pwm;
 
 	/* request pwm device with the consumer name */

@@ -248,11 +247,15 @@ static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
 		lp->pwm = pwm;
 	}
 
-	pwm_config(lp->pwm, duty, period);
-	if (duty)
-		pwm_enable(lp->pwm);
+	pwm_get_state(lp->pwm, &pstate);
+	pstate.period = lp->pdata->period_ns;
+	pstate.duty_cycle = br * pstate.period / max_br;
+	if (pstate.duty_cycle)
+		pstate.enabled = true;
 	else
-		pwm_disable(lp->pwm);
+		pstate.enabled = false;
+
+	pwm_apply_state(lp->pwm, &pstate);
 }
 
 static int lp855x_bl_update_status(struct backlight_device *bl)

@@ -124,16 +124,13 @@ static int lp8788_backlight_configure(struct lp8788_bl *bl)
 
 static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br)
 {
-	unsigned int period;
-	unsigned int duty;
 	struct device *dev;
+	struct pwm_state pstate;
 	struct pwm_device *pwm;
 
 	if (!bl->pdata)
 		return;
 
-	period = bl->pdata->period_ns;
-	duty = br * period / max_br;
 	dev = bl->lp->dev;
 
 	/* request PWM device with the consumer name */

@@ -147,11 +144,15 @@ static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br)
 		bl->pwm = pwm;
 	}
 
-	pwm_config(bl->pwm, duty, period);
-	if (duty)
-		pwm_enable(bl->pwm);
+	pwm_get_state(bl->pwm, &pstate);
+	pstate.period = bl->pdata->period_ns;
+	pstate.duty_cycle = br * pstate.period / max_br;
+	if (pstate.duty_cycle)
+		pstate.enabled = true;
 	else
-		pwm_disable(bl->pwm);
+		pstate.enabled = false;
+
+	pwm_apply_state(bl->pwm, &pstate);
 }
 
 static int lp8788_bl_update_status(struct backlight_device *bl_dev)

@@ -289,6 +289,8 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 	struct pwm_args pargs = { };
 
 	if (par->device_info->need_pwm) {
+		struct pwm_state pstate;
+
 		par->pwm = pwm_get(&par->client->dev, NULL);
 		if (IS_ERR(par->pwm)) {
 			dev_err(&par->client->dev, "Could not get PWM from device tree!\n");

@@ -296,10 +298,14 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 		}
 
 		pwm_get_args(par->pwm, &pargs);
+		pwm_get_state(par->pwm, &pstate);
 		par->pwm_period = pargs.period;
+
 		/* Enable the PWM */
-		pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
-		pwm_enable(par->pwm);
+		pstate.period = pargs.period;
+		pstate.duty_cycle = pstate.period / 2;
+		pstate.enabled = true;
+		pwm_apply_state(par->pwm, &pstate);
 
 		dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
 			par->pwm->pwm, par->pwm_period);

@@ -685,8 +691,12 @@ static int ssd1307fb_probe(struct i2c_client *client,
 bl_init_error:
 	unregister_framebuffer(info);
 panel_init_error:
-	if (par->device_info->need_pwm) {
-		pwm_disable(par->pwm);
+	if (par->device_info->need_pwm && par->pwm) {
+		struct pwm_state pstate;
+
+		pwm_get_state(par->pwm, &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(par->pwm, &pstate);
 		pwm_put(par->pwm);
 	};
 reset_oled_error:

@@ -707,7 +717,11 @@ static int ssd1307fb_remove(struct i2c_client *client)
 
 	unregister_framebuffer(info);
 	if (par->device_info->need_pwm) {
-		pwm_disable(par->pwm);
+		struct pwm_state pstate;
+
+		pwm_get_state(par->pwm, &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(par->pwm, &pstate);
 		pwm_put(par->pwm);
 	};
 	fb_deferred_io_cleanup(info);

@@ -538,10 +538,10 @@ static u32 bxt_get_backlight(struct intel_connector *connector)
 static u32 pwm_get_backlight(struct intel_connector *connector)
 {
 	struct intel_panel *panel = &connector->panel;
-	int duty_ns;
+	struct pwm_state pstate;
 
-	duty_ns = pwm_get_duty_cycle(panel->backlight.pwm);
-	return DIV_ROUND_UP(duty_ns * 100, CRC_PMIC_PWM_PERIOD_NS);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	return DIV_ROUND_UP(pstate.duty_cycle * 100, CRC_PMIC_PWM_PERIOD_NS);
 }
 
 static u32 intel_panel_get_backlight(struct intel_connector *connector)

@@ -630,9 +630,12 @@ static void bxt_set_backlight(struct intel_connector *connector, u32 level)
 static void pwm_set_backlight(struct intel_connector *connector, u32 level)
 {
 	struct intel_panel *panel = &connector->panel;
-	int duty_ns = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100);
+	struct pwm_state pstate;
 
-	pwm_config(panel->backlight.pwm, duty_ns, CRC_PMIC_PWM_PERIOD_NS);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	pstate.duty_cycle = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100);
+	pstate.period = CRC_PMIC_PWM_PERIOD_NS;
+	pwm_apply_state(panel->backlight.pwm, &pstate);
 }
 
 static void

@@ -801,11 +804,15 @@ static void bxt_disable_backlight(struct intel_connector *connector)
 static void pwm_disable_backlight(struct intel_connector *connector)
 {
 	struct intel_panel *panel = &connector->panel;
+	struct pwm_state pstate;
 
 	/* Disable the backlight */
-	pwm_config(panel->backlight.pwm, 0, CRC_PMIC_PWM_PERIOD_NS);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	pstate.duty_cycle = 0;
+	pwm_apply_state(panel->backlight.pwm, &pstate);
 	usleep_range(2000, 3000);
-	pwm_disable(panel->backlight.pwm);
+	pstate.enabled = false;
+	pwm_apply_state(panel->backlight.pwm, &pstate);
 }
 
 void intel_panel_disable_backlight(struct intel_connector *connector)

@@ -1068,8 +1075,11 @@ static void bxt_enable_backlight(struct intel_connector *connector)
 static void pwm_enable_backlight(struct intel_connector *connector)
 {
 	struct intel_panel *panel = &connector->panel;
+	struct pwm_state pstate;
 
-	pwm_enable(panel->backlight.pwm);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	pstate.enabled = true;
+	pwm_apply_state(panel->backlight.pwm, &pstate);
 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
 }
 

@@ -1630,6 +1640,7 @@ static int pwm_setup_backlight(struct intel_connector *connector,
 {
 	struct drm_device *dev = connector->base.dev;
 	struct intel_panel *panel = &connector->panel;
+	struct pwm_state pstate;
 	int retval;
 
 	/* Get the PWM chip for backlight control */

@@ -1640,8 +1651,10 @@ static int pwm_setup_backlight(struct intel_connector *connector,
 		return -ENODEV;
 	}
 
-	retval = pwm_config(panel->backlight.pwm, CRC_PMIC_PWM_PERIOD_NS,
-			    CRC_PMIC_PWM_PERIOD_NS);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	pstate.period = CRC_PMIC_PWM_PERIOD_NS;
+	pstate.duty_cycle = CRC_PMIC_PWM_PERIOD_NS;
+	retval = pwm_apply_state(panel->backlight.pwm, &pstate);
 	if (retval < 0) {
 		DRM_ERROR("Failed to configure the pwm chip\n");
 		pwm_put(panel->backlight.pwm);

@@ -1651,9 +1664,9 @@ static int pwm_setup_backlight(struct intel_connector *connector,
 
 	panel->backlight.min = 0; /* 0% */
 	panel->backlight.max = 100; /* 100% */
-	panel->backlight.level = DIV_ROUND_UP(
-				 pwm_get_duty_cycle(panel->backlight.pwm) * 100,
-				 CRC_PMIC_PWM_PERIOD_NS);
+	pwm_get_state(panel->backlight.pwm, &pstate);
+	panel->backlight.level = DIV_ROUND_UP(pstate.duty_cycle * 100,
+					      pstate.period);
 	panel->backlight.enabled = panel->backlight.level != 0;
 
 	return 0;

@@ -384,10 +384,15 @@ static struct pwm_device *lcd_pwm;
 
 static void rx1950_lcd_power(int enable)
 {
+	struct pwm_state pstate;
 	int i;
 	static int enabled;
+
 	if (enabled = enable)
 		return;
+
+	pwm_get_state(lcd_pwm, &pstate);
+
 	if (!enable) {
 
 		/* GPC11-GPC15->OUTPUT */

@@ -433,15 +438,21 @@ static void rx1950_lcd_power(int enable)
 
 		/* GPB1->OUTPUT, GPB1->0 */
 		gpio_direction_output(S3C2410_GPB(1), 0);
-		pwm_config(lcd_pwm, 0, LCD_PWM_PERIOD);
+
+		pstate.enabled = false;
+		pstate.period = LCD_PWM_PERIOD;
+		pstate.duty_cycle = 0;
+		pwm_apply_state(lcd_pwm, &pstate);
 		pwm_disable(lcd_pwm);
 
 		/* GPC0->0, GPC10->0 */
 		gpio_direction_output(S3C2410_GPC(0), 0);
 		gpio_direction_output(S3C2410_GPC(10), 0);
 	} else {
-		pwm_config(lcd_pwm, LCD_PWM_DUTY, LCD_PWM_PERIOD);
-		pwm_enable(lcd_pwm);
+		pstate.enabled = true;
+		pstate.period = LCD_PWM_PERIOD;
+		pstate.duty_cycle = LCD_PWM_DUTY;
+		pwm_apply_state(lcd_pwm, &pstate);
 
 		gpio_direction_output(S3C2410_GPC(0), 1);
 		gpio_direction_output(S3C2410_GPC(5), 1);

@@ -43,8 +43,22 @@ struct pwm_bl_data {
 	void			(*exit)(struct device *);
 };
 
+static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
+{
+	unsigned int lth = pb->lth_brightness;
+	int duty_cycle;
+
+	if (pb->levels)
+		duty_cycle = pb->levels[brightness];
+	else
+		duty_cycle = brightness;
+
+	return (duty_cycle * (pb->period - lth) / pb->scale) + lth;
+}
+
 static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
 {
+	struct pwm_state pstate;
 	int err;
 
 	if (pb->enabled)

@@ -57,17 +71,24 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
 	if (pb->enable_gpio)
 		gpiod_set_value(pb->enable_gpio, 1);
 
-	pwm_enable(pb->pwm);
+	pwm_get_state(pb->pwm, &pstate);
+	pstate.duty_cycle = compute_duty_cycle(pb, brightness);
+	pstate.enabled = true;
+	pwm_apply_state(pb->pwm, &pstate);
 	pb->enabled = true;
 }
 
 static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 {
+	struct pwm_state pstate;
+
 	if (!pb->enabled)
 		return;
 
-	pwm_config(pb->pwm, 0, pb->period);
-	pwm_disable(pb->pwm);
+	pwm_get_state(pb->pwm, &pstate);
+	pstate.duty_cycle = 0;
+	pstate.enabled = false;
+	pwm_apply_state(pb->pwm, &pstate);
 
 	if (pb->enable_gpio)
 		gpiod_set_value(pb->enable_gpio, 0);

@@ -76,24 +97,10 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 	pb->enabled = false;
 }
 
-static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
-{
-	unsigned int lth = pb->lth_brightness;
-	int duty_cycle;
-
-	if (pb->levels)
-		duty_cycle = pb->levels[brightness];
-	else
-		duty_cycle = brightness;
-
-	return (duty_cycle * (pb->period - lth) / pb->scale) + lth;
-}
-
 static int pwm_backlight_update_status(struct backlight_device *bl)
 {
 	struct pwm_bl_data *pb = bl_get_data(bl);
 	int brightness = bl->props.brightness;
-	int duty_cycle;
 
 	if (bl->props.power != FB_BLANK_UNBLANK ||
 	    bl->props.fb_blank != FB_BLANK_UNBLANK ||

@@ -104,8 +111,6 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
 		brightness = pb->notify(pb->dev, brightness);
 
 	if (brightness > 0) {
-		duty_cycle = compute_duty_cycle(pb, brightness);
-		pwm_config(pb->pwm, duty_cycle, pb->period);
 		pwm_backlight_power_on(pb, brightness);
 	} else
 		pwm_backlight_power_off(pb);

@@ -40,13 +40,18 @@ struct led_pwm_priv {
 static void __led_pwm_set(struct led_pwm_data *led_dat)
 {
 	int new_duty = led_dat->duty;
+	struct pwm_state pstate;
 
-	pwm_config(led_dat->pwm, new_duty, led_dat->period);
+	pwm_get_state(led_dat->pwm, &pstate);
+	pstate.duty_cycle = new_duty;
+	pstate.period = led_dat->period;
 
 	if (new_duty = 0)
-		pwm_disable(led_dat->pwm);
+		pstate.enabled = false;
 	else
-		pwm_enable(led_dat->pwm);
+		pstate.enabled = true;
+
+	pwm_apply_state(led_dat->pwm, &pstate);
 }
 
 static void led_pwm_set(struct led_classdev *led_cdev,

@@ -34,7 +34,7 @@ static int pwm_beeper_event(struct input_dev *input,
 {
 	int ret = 0;
 	struct pwm_beeper *beeper = input_get_drvdata(input);
-	unsigned long period;
+	struct pwm_state pstate;
 
 	if (type != EV_SND || value < 0)
 		return -EINVAL;

@@ -49,19 +49,22 @@ static int pwm_beeper_event(struct input_dev *input,
 		return -EINVAL;
 	}
 
+	pwm_get_state(beeper->pwm, &pstate);
+
 	if (value = 0) {
-		pwm_disable(beeper->pwm);
+		pstate.enabled = false;
 	} else {
-		period = HZ_TO_NANOSECONDS(value);
-		ret = pwm_config(beeper->pwm, period / 2, period);
-		if (ret)
-			return ret;
-		ret = pwm_enable(beeper->pwm);
-		if (ret)
-			return ret;
-		beeper->period = period;
+		pstate.enabled = false;
+		pstate.period = HZ_TO_NANOSECONDS(value);
+		pstate.duty_cycle = pstate.period / 2;
 	}
 
+	ret = pwm_apply_state(beeper->pwm, &pstate);
+	if (ret)
+		return ret;
+
+	beeper->period = value ? pstate.period : 0;
+
 	return 0;
 }
 

@@ -132,10 +135,13 @@ err_free:
 static int pwm_beeper_remove(struct platform_device *pdev)
 {
 	struct pwm_beeper *beeper = platform_get_drvdata(pdev);
+	struct pwm_state pstate;
 
 	input_unregister_device(beeper->input);
 
-	pwm_disable(beeper->pwm);
+	pwm_get_state(beeper->pwm, &pstate);
+	pstate.enabled = false;
+	pwm_apply_state(beeper->pwm, &pstate);
 	pwm_free(beeper->pwm);
 
 	kfree(beeper);

@@ -147,8 +153,13 @@ static int __maybe_unused pwm_beeper_suspend(struct device *dev)
 {
 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
 
-	if (beeper->period)
-		pwm_disable(beeper->pwm);
+	if (beeper->period) {
+		struct pwm_state pstate;
+
+		pwm_get_state(beeper->pwm, &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(beeper->pwm, &pstate);
+	}
 
 	return 0;
 }

@@ -158,8 +169,13 @@ static int __maybe_unused pwm_beeper_resume(struct device *dev)
 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
 
 	if (beeper->period) {
-		pwm_config(beeper->pwm, beeper->period / 2, beeper->period);
-		pwm_enable(beeper->pwm);
+		struct pwm_state pstate;
+
+		pwm_get_state(beeper->pwm, &pstate);
+		pstate.period = beeper->period;
+		pstate.duty_cycle = beeper->period / 2;
+		pstate.enabled = true;
+		pwm_apply_state(beeper->pwm, &pstate);
 	}
 
 	return 0;

@@ -72,8 +72,12 @@ static int max8997_haptic_set_duty_cycle(struct max8997_haptic *chip)
 	int ret = 0;
 
 	if (chip->mode = MAX8997_EXTERNAL_MODE) {
-		unsigned int duty = chip->pwm_period * chip->level / 100;
-		ret = pwm_config(chip->pwm, duty, chip->pwm_period);
+		struct pwm_state pstate;
+
+		pwm_get_state(chip->pwm, &pstate);
+		pstate.period = chip->pwm_period;
+		pstate.duty_cycle = chip->pwm_period * chip->level / 100;
+		ret = pwm_apply_state(chip->pwm, &pstate);
 	} else {
 		int i;
 		u8 duty_index = 0;

@@ -188,7 +192,11 @@ static void max8997_haptic_enable(struct max8997_haptic *chip)
 		}
 		max8997_haptic_configure(chip);
 		if (chip->mode = MAX8997_EXTERNAL_MODE) {
-			error = pwm_enable(chip->pwm);
+			struct pwm_state pstate;
+
+			pwm_get_state(chip->pwm, &pstate);
+			pstate.enabled = true;
+			error = pwm_apply_state(chip->pwm, &pstate);
 			if (error) {
 				dev_err(chip->dev, "Failed to enable PWM\n");
 				regulator_disable(chip->regulator);

@@ -209,8 +217,13 @@ static void max8997_haptic_disable(struct max8997_haptic *chip)
 	if (chip->enabled) {
 		chip->enabled = false;
 		max8997_haptic_configure(chip);
-		if (chip->mode = MAX8997_EXTERNAL_MODE)
-			pwm_disable(chip->pwm);
+		if (chip->mode = MAX8997_EXTERNAL_MODE) {
+			struct pwm_state pstate;
+
+			pwm_get_state(chip->pwm, &pstate);
+			pstate.enabled = false;
+			pwm_apply_state(chip->pwm, &pstate);
+		}
 		regulator_disable(chip->regulator);
 	}
 

@@ -28,15 +28,29 @@ static inline struct clk_pwm *to_clk_pwm(struct clk_hw *hw)
 static int clk_pwm_prepare(struct clk_hw *hw)
 {
 	struct clk_pwm *clk_pwm = to_clk_pwm(hw);
+	struct pwm_state pstate;
 
-	return pwm_enable(clk_pwm->pwm);
+	pwm_get_state(clk_pwm->pwm, &pstate);
+	if (pstate.enabled)
+		return 0;
+
+	pstate.enabled = true;
+
+	return pwm_apply_state(clk_pwm->pwm, &pstate);
 }
 
 static void clk_pwm_unprepare(struct clk_hw *hw)
 {
 	struct clk_pwm *clk_pwm = to_clk_pwm(hw);
+	struct pwm_state pstate;
+
+	pwm_get_state(clk_pwm->pwm, &pstate);
+	if (!pstate.enabled)
+		return;
 
-	pwm_disable(clk_pwm->pwm);
+	pstate.enabled = false;
+
+	pwm_apply_state(clk_pwm->pwm, &pstate);
 }
 
 static unsigned long clk_pwm_recalc_rate(struct clk_hw *hw,

@@ -56,6 +70,7 @@ static const struct clk_ops clk_pwm_ops = {
 static int clk_pwm_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
+	struct pwm_state pstate;
 	struct pwm_args pargs = { };
 	struct clk_init_data init;
 	struct clk_pwm *clk_pwm;

@@ -88,7 +103,12 @@ static int clk_pwm_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	ret = pwm_config(pwm, (pargs.period + 1) >> 1, pargs.period);
+	pwm_get_state(pwm, &pstate);
+	pstate.period = pargs.period;
+	pstate.polarity = pargs.polarity;
+	pstate.duty_cycle = (pargs.period + 1) >> 1;
+
+	ret = pwm_apply_state(pwm, &pstate);
 	if (ret < 0)
 		return ret;
 

@@ -225,8 +225,8 @@ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state);
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
-			     int period_ns)
+static inline int __deprecated pwm_config(struct pwm_device *pwm, int duty_ns,
+					  int period_ns)
 {
 	struct pwm_state pstate;
 

@@ -252,8 +252,8 @@ static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-static inline int pwm_set_polarity(struct pwm_device *pwm,
-				   enum pwm_polarity polarity)
+static inline int __deprecated pwm_set_polarity(struct pwm_device *pwm,
+						enum pwm_polarity polarity)
 {
 	struct pwm_state pstate;
 

@@ -284,7 +284,7 @@ static inline int pwm_set_polarity(struct pwm_device *pwm,
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-static inline int pwm_enable(struct pwm_device *pwm)
+static inline int __deprecated pwm_enable(struct pwm_device *pwm)
 {
 	struct pwm_state pstate;
 

@@ -303,7 +303,7 @@ static inline int pwm_enable(struct pwm_device *pwm)
  * pwm_disable() - stop a PWM output toggling
  * @pwm: PWM device
  */
-static inline void pwm_disable(struct pwm_device *pwm)
+static inline void __deprecated pwm_disable(struct pwm_device *pwm)
 {
 	struct pwm_state pstate;
 

@@ -360,24 +360,24 @@ static inline int pwm_apply_state(struct pwm_device *pwm,
 	return -ENOTSUPP;
 }
 
-static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
-			     int period_ns)
+static inline int __deprecated pwm_config(struct pwm_device *pwm, int duty_ns,
+					  int period_ns)
 {
 	return -EINVAL;
 }
 
-static inline int pwm_set_polarity(struct pwm_device *pwm,
-				   enum pwm_polarity polarity)
+static inline int __deprecated pwm_set_polarity(struct pwm_device *pwm,
+						enum pwm_polarity polarity)
 {
 	return -ENOTSUPP;
 }
 
-static inline int pwm_enable(struct pwm_device *pwm)
+static inline int __deprecated pwm_enable(struct pwm_device *pwm)
 {
 	return -EINVAL;
 }
 
-static inline void pwm_disable(struct pwm_device *pwm)
+static inline void __deprecated pwm_disable(struct pwm_device *pwm)
 {
 }
 

@@ -42,9 +42,23 @@ variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.
 
 After being requested, a PWM has to be configured using:
 
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
+int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *pstate);
 
-To start/stop toggling the PWM output use pwm_enable()/pwm_disable().
+This API controls both the PWM period/duty_cycle config and the
+enable/disable state.
+
+The legacy pwm_config(), pwm_enable() and pwm_disable() are now deprecated,
+and should be replaced by pwm_apply_state() calls.
+
+The PWM user API also allows one to query the PWM state with pwm_get_state().
+
+In addition to the PWM state, the PWM API also exposes PWM arguments, which
+are the reference PWM config one should use on this PWM.
+PWM arguments are usually platform-specific and allows the PWM user to only
+care about dutycycle relatively to the full period (like, duty = 50% of the
+period). struct pwm_args contains 2 fields (period and polarity) and should
+be used to set the initial PWM config (usually done in the probe function
+of the PWM user). PWM arguments are retrieved with pwm_get_args().
 
 Using PWMs with the sysfs interface
 -----------------------------------

@@ -105,6 +119,15 @@ goes low for the remainder of the period. Conversely, a signal with inversed
 polarity starts low for the duration of the duty cycle and goes high for the
 remainder of the period.
 
+Drivers are encouraged to implement ->apply() instead of the legacy
+->enable(), ->disable() and ->config() methods. Doing that should provide
+atomicity in the PWM config workflow, which is required when the PWM controls
+a critical device (like a regulator).
+
+The implementation of ->get_state() (a method used to retrieve initial PWM
+state) is also encouraged for the same reason: letting the PWM user know
+about the current PWM state would allow him to avoid glitches.
+
 Locking
 -------
 

@@ -48,10 +48,35 @@ struct pwm_voltages {
 /**
  * Voltage table call-backs
  */
+static void pwm_regulator_init_state(struct regulator_dev *rdev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pwm_state;
+	unsigned int dutycycle;
+	int i;
+
+	pwm_get_state(drvdata->pwm, &pwm_state);
+
+	if (!pwm_state.period)
+		return;
+
+	dutycycle = (pwm_state.duty_cycle * 100) / pwm_state.period;
+
+	for (i = 0; i < rdev->desc->n_voltages; i++) {
+		if (dutycycle = drvdata->duty_cycle_table[i].dutycycle) {
+			drvdata->state = i;
+			return;
+		}
+	}
+}
+
 static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 
+	if (drvdata->state < 0)
+		pwm_regulator_init_state(rdev);
+
 	return drvdata->state;
 }
 

@@ -234,6 +259,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 		return ret;
 	}
 
+	drvdata->state			= -EINVAL;
 	drvdata->duty_cycle_table	= duty_cycle_table;
 	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
 	       sizeof(drvdata->ops));

@@ -59,16 +59,18 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
 					 unsigned selector)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
-	struct pwm_args pargs = { };
-	int dutycycle;
+	struct pwm_state pstate = { };
+	u64 dutycycle;
 	int ret;
 
-	pwm_get_args(drvdata->pwm, &pargs);
+	pwm_get_state(drvdata->pwm, &pstate);
 
-	dutycycle = (pargs.period *
-		    drvdata->duty_cycle_table[selector].dutycycle) / 100;
+	dutycycle = drvdata->duty_cycle_table[selector].dutycycle;
+	dutycycle *= pstate.period;
+	do_div(dutycycle, 100);
+	pstate.duty_cycle = dutycycle;
 
-	ret = pwm_config(drvdata->pwm, dutycycle, pargs.period);
+	ret = pwm_apply_state(drvdata->pwm, &pstate);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM\n");
 		return ret;

@@ -93,24 +95,39 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev,
 static int pwm_regulator_enable(struct regulator_dev *dev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+	struct pwm_state pstate = { };
+
+	pwm_get_state(drvdata->pwm, &pstate);
+	if (pstate.enabled)
+		return 0;
+
+	pstate.enabled = true;
 
-	return pwm_enable(drvdata->pwm);
+	return pwm_apply_state(drvdata->pwm, &pstate);
 }
 
 static int pwm_regulator_disable(struct regulator_dev *dev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+	struct pwm_state pstate = { };
 
-	pwm_disable(drvdata->pwm);
+	pwm_get_state(drvdata->pwm, &pstate);
+	if (!pstate.enabled)
+		return 0;
 
-	return 0;
+	pstate.enabled = false;
+
+	return pwm_apply_state(drvdata->pwm, &pstate);
 }
 
 static int pwm_regulator_is_enabled(struct regulator_dev *dev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+	struct pwm_state pstate = { };
 
-	return pwm_is_enabled(drvdata->pwm);
+	pwm_get_state(drvdata->pwm, &pstate);
+
+	return pstate.enabled;
 }
 
 /**

@@ -138,25 +155,22 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 	unsigned int ramp_delay = rdev->constraints->ramp_delay;
-	struct pwm_args pargs = { };
-	int duty_cycle;
+	struct pwm_state pstate = { };
+	u64 duty_cycle;
 	int ret;
 
-	pwm_get_args(drvdata->pwm, &pargs);
+	pwm_get_state(drvdata->pwm, &pstate);
 	duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);
+	duty_cycle *= pstate.period;
+	do_div(duty_cycle, 100);
+	pstate.duty_cycle = duty_cycle;
 
-	ret = pwm_config(drvdata->pwm, (pargs.period / 100) * duty_cycle,
-			 pargs.period);
+	ret = pwm_apply_state(drvdata->pwm, &pstate);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM\n");
 		return ret;
 	}
 
-	ret = pwm_enable(drvdata->pwm);
-	if (ret) {
-		dev_err(&rdev->dev, "Failed to enable PWM\n");
-		return ret;
-	}
 	drvdata->volt_uV = min_uV;
 
 	/* Delay required by PWM regulator to settle to the new voltage */

@@ -240,6 +240,52 @@ static int pwm_regulator_init_continuous(struct platform_device *pdev,
 	return 0;
 }
 
+static int pwm_regulator_adjust_pwm_config(struct pwm_regulator_data *drvdata)
+{
+	struct pwm_state pstate = { };
+	struct pwm_args pargs = { };
+
+	pwm_get_args(drvdata->pwm, &pargs);
+	pwm_get_state(drvdata->pwm, &pstate);
+
+	/*
+	 * if the current period is zero this either means the PWM driver
+	 * does not support initial state retrieval or the PWM was not
+	 * configured.
+	 * In any case, we setup the new period and poloarity, and assign a
+	 * duty_cycle of 0.
+	 */
+	if (!pstate.period) {
+		pstate.duty_cycle = 0;
+		pstate.period = pargs.period;
+		pstate.polarity = pargs.polarity;
+
+		return pwm_apply_state(drvdata->pwm, &pstate);
+	}
+
+	/*
+	 * Adjust the PWM dutycycle/period based on the period value provided
+	 * in PWM args.
+	 */
+	if (pargs.period != pstate.period) {
+		u64 dutycycle = (u64)pstate.duty_cycle * pargs.period;
+
+		do_div(dutycycle, pstate.period);
+		pstate.duty_cycle = dutycycle;
+		pstate.period = pargs.period;
+	}
+
+	/*
+	 * If the polarity changed, we should also change the dutycycle value.
+	 */
+	if (pargs.polarity != pstate.polarity) {
+		pstate.polarity = pargs.polarity;
+		pstate.duty_cycle = pstate.period - pstate.duty_cycle;
+	}
+
+	return pwm_apply_state(drvdata->pwm, &pstate);
+}
+
 static int pwm_regulator_probe(struct platform_device *pdev)
 {
 	const struct regulator_init_data *init_data;

@@ -283,6 +329,10 @@ static int pwm_regulator_probe(struct platform_device *pdev)
 		return PTR_ERR(drvdata->pwm);
 	}
 
+	ret = pwm_regulator_adjust_pwm_config(drvdata);
+	if (ret)
+		return ret;
+
 	regulator = devm_regulator_register(&pdev->dev,
 					    &drvdata->desc, &config);
 	if (IS_ERR(regulator)) {

@@ -238,6 +238,46 @@ static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	mutex_unlock(&pc->sti_pwm_lock);
 }
 
+static void sti_pwm_get_state(struct pwm_chip *chip,
+			      struct pwm_device *pwm,
+			      struct pwm_state *pstate)
+{
+	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
+	unsigned int regval, prescaler;
+	u64 timens;
+	int ret;
+
+	/* The clock has to be enabled to access PWM registers */
+	ret = clk_enable(pc->clk);
+	if (ret) {
+		dev_err(chip->dev, "Failed to enable PWM clk");
+		return;
+	}
+
+	regmap_field_read(pc->prescale_high, &regval);
+	prescaler = regval << 4;
+	regmap_field_read(pc->prescale_low, &regval);
+	prescaler |= regval;
+
+	timens = (u64)(prescaler + 1) * NSEC_PER_SEC *
+		 (pc->cdata->max_pwm_cnt + 1);
+	do_div(timens, pc->clk_rate);
+
+	pstate->period = timens;
+
+	regmap_read(pc->regmap, STI_DS_REG(pwm->hwpwm), &regval);
+	timens = (u64)(regval + 1) * pstate->period;
+	do_div(timens, pc->cdata->max_pwm_cnt + 1);
+	pstate->duty_cycle = timens;
+
+	regmap_field_read(pc->pwm_en, &regval);
+	pstate->enabled = regval;
+
+	pstate->polarity = PWM_POLARITY_NORMAL;
+
+	clk_disable(pc->clk);
+}
+
 static void sti_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);

@@ -249,6 +289,7 @@ static const struct pwm_ops sti_pwm_ops = {
 	.config = sti_pwm_config,
 	.enable = sti_pwm_enable,
 	.disable = sti_pwm_disable,
+	.get_state = sti_pwm_get_state,
 	.free = sti_pwm_free,
 	.owner = THIS_MODULE,
 };

@@ -50,7 +50,8 @@ struct rockchip_pwm_data {
 	const struct pwm_ops *ops;
 
 	void (*set_enable)(struct pwm_chip *chip,
-			   struct pwm_device *pwm, bool enable);
+			   struct pwm_device *pwm, bool enable,
+			   enum pwm_polarity polarity);
 	void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
 			  struct pwm_state *pstate);
 };

@@ -61,7 +62,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
 }
 
 static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
-				       struct pwm_device *pwm, bool enable)
+				       struct pwm_device *pwm, bool enable,
+				       enum pwm_polarity polarity)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;

@@ -91,14 +93,15 @@ static void rockchip_pwm_get_state_v1(struct pwm_chip *chip,
 }
 
 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
-				       struct pwm_device *pwm, bool enable)
+				       struct pwm_device *pwm, bool enable,
+				       enum pwm_polarity polarity)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
 			  PWM_CONTINUOUS;
 	u32 val;
 
-	if (pwm_get_polarity(pwm) = PWM_POLARITY_INVERSED)
+	if (polarity = PWM_POLARITY_INVERSED)
 		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
 	else
 		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;

@@ -168,7 +171,6 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	unsigned long period, duty;
 	u64 clk_rate, div;
-	int ret;
 
 	clk_rate = clk_get_rate(pc->clk);
 

@@ -185,15 +187,8 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
 	duty = div;
 
-	ret = clk_enable(pc->clk);
-	if (ret)
-		return ret;
-
 	writel(period, pc->base + pc->data->regs.period);
 	writel(duty, pc->base + pc->data->regs.duty);
-	writel(0, pc->base + pc->data->regs.cntr);
-
-	clk_disable(pc->clk);
 
 	return 0;
 }

@@ -211,43 +206,63 @@ static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
 	return 0;
 }
 
-static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      struct pwm_state *state)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	struct pwm_state curstate;
+	bool enabled;
 	int ret;
 
+	pwm_get_state(pwm, &curstate);
+	enabled = curstate.enabled;
+
 	ret = clk_enable(pc->clk);
 	if (ret)
 		return ret;
 
-	pc->data->set_enable(chip, pwm, true);
+	if (state->polarity != curstate.polarity && enabled) {
+		pc->data->set_enable(chip, pwm, false, state->polarity);
+		enabled = false;
+	}
 
-	return 0;
-}
+	ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
+	if (ret) {
+		if (enabled != curstate.enabled)
+			pc->data->set_enable(chip, pwm, !enabled,
+					     state->polarity);
 
-static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+		goto out;
+	}
 
-	pc->data->set_enable(chip, pwm, false);
+	if (state->enabled != enabled)
+		pc->data->set_enable(chip, pwm, state->enabled,
+				     state->polarity);
 
+	/*
+	 * Update the state with the real hardware, which can differ a bit
+	 * because of period/duty_cycle approximation.
+	 */
+	rockchip_pwm_get_state(chip, pwm, state);
+
+out:
 	clk_disable(pc->clk);
+
+	return ret;
 }
 
 static const struct pwm_ops rockchip_pwm_ops_v1 = {
 	.get_state = rockchip_pwm_get_state,
 	.config = rockchip_pwm_config,
-	.enable = rockchip_pwm_enable,
-	.disable = rockchip_pwm_disable,
+	.apply = rockchip_pwm_apply,
 	.owner = THIS_MODULE,
 };
 
 static const struct pwm_ops rockchip_pwm_ops_v2 = {
 	.get_state = rockchip_pwm_get_state,
 	.config = rockchip_pwm_config,
+	.apply = rockchip_pwm_apply,
 	.set_polarity = rockchip_pwm_set_polarity,
-	.enable = rockchip_pwm_enable,
-	.disable = rockchip_pwm_disable,
 	.owner = THIS_MODULE,
 };
 

@@ -305,9 +305,12 @@ static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
 	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct pwm_state pstate;
 
-	pwm_disable(pwm);
-	pwm_set_duty_cycle(pwm, 0);
+	pwm_get_state(pwm, &pstate);
+	pstate.duty_cycle = 0;
+	pstate.enabled = false;
+	pwm_apply_state(pwm, &pstate);
 	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
 }
 

@@ -138,8 +138,13 @@ static int lpc32xx_pwm_remove(struct platform_device *pdev)
 	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
 	unsigned int i;
 
-	for (i = 0; i < lpc32xx->chip.npwm; i++)
-		pwm_disable(&lpc32xx->chip.pwms[i]);
+	for (i = 0; i < lpc32xx->chip.npwm; i++) {
+		struct pwm_state pstate;
+
+		pwm_get_state(&lpc32xx->chip.pwms[i], &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(&lpc32xx->chip.pwms[i], &pstate);
+	}
 
 	return pwmchip_remove(&lpc32xx->chip);
 }

@@ -233,8 +233,13 @@ static int spear_pwm_remove(struct platform_device *pdev)
 	struct spear_pwm_chip *pc = platform_get_drvdata(pdev);
 	int i;
 
-	for (i = 0; i < NUM_PWM; i++)
-		pwm_disable(&pc->chip.pwms[i]);
+	for (i = 0; i < NUM_PWM; i++) {
+		struct pwm_state pstate;
+
+		pwm_get_state(&pc->chip.pwms[i], &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(&pc->chip.pwms[i], &pstate);
+	}
 
 	/* clk was prepared in probe, hence unprepare it here */
 	clk_unprepare(pc->clk);

@@ -435,8 +435,13 @@ static int sti_pwm_remove(struct platform_device *pdev)
 	struct sti_pwm_chip *pc = platform_get_drvdata(pdev);
 	unsigned int i;
 
-	for (i = 0; i < pc->cdata->num_chan; i++)
-		pwm_disable(&pc->chip.pwms[i]);
+	for (i = 0; i < pc->cdata->num_chan; i++) {
+		struct pwm_state pstate;
+
+		pwm_get_state(&pc->chip.pwms[i], &pstate);
+		pstate.enabled = false;
+		pwm_apply_state(&pc->chip.pwms[i], &pstate);
+	}
 
 	clk_unprepare(pc->clk);
 

@@ -51,6 +51,8 @@ struct rockchip_pwm_data {
 
 	void (*set_enable)(struct pwm_chip *chip,
 			   struct pwm_device *pwm, bool enable);
+	void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
+			  struct pwm_state *pstate);
 };
 
 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)

@@ -75,6 +77,19 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
+static void rockchip_pwm_get_state_v1(struct pwm_chip *chip,
+				      struct pwm_device *pwm,
+				      struct pwm_state *pstate)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
+	u32 val;
+
+	val = readl(pc->base + pc->data->regs.ctrl);
+	if ((val & enable_conf) = enable_conf)
+		pstate->enabled = true;
+}
+
 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 				       struct pwm_device *pwm, bool enable)
 {

@@ -98,6 +113,55 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
+static void rockchip_pwm_get_state_v2(struct pwm_chip *chip,
+				      struct pwm_device *pwm,
+				      struct pwm_state *pstate)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+			  PWM_CONTINUOUS;
+	u32 val;
+
+	val = readl(pc->base + pc->data->regs.ctrl);
+	if ((val & enable_conf) != enable_conf)
+		return;
+
+	pstate->enabled = true;
+
+	if (!(val & PWM_DUTY_POSITIVE))
+		pstate->polarity = PWM_POLARITY_INVERSED;
+}
+
+static void rockchip_pwm_get_state(struct pwm_chip *chip,
+				   struct pwm_device *pwm,
+				   struct pwm_state *pstate)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	unsigned long clk_rate;
+	u64 tmp;
+	int ret;
+
+	ret = clk_enable(pc->clk);
+	if (ret)
+		return;
+
+	clk_rate = clk_get_rate(pc->clk);
+
+	tmp = readl(pc->base + pc->data->regs.period);
+	tmp *= pc->data->prescaler * NSEC_PER_SEC;
+	do_div(tmp, clk_rate);
+	pstate->period = tmp;
+
+	tmp = readl(pc->base + pc->data->regs.duty);
+	tmp *= pc->data->prescaler * NSEC_PER_SEC;
+	do_div(tmp, clk_rate);
+	pstate->duty_cycle = tmp;
+
+	pc->data->get_state(chip, pwm, pstate);
+
+	clk_disable(pc->clk);
+}
+
 static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			       int duty_ns, int period_ns)
 {

@@ -171,6 +235,7 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 }
 
 static const struct pwm_ops rockchip_pwm_ops_v1 = {
+	.get_state = rockchip_pwm_get_state,
 	.config = rockchip_pwm_config,
 	.enable = rockchip_pwm_enable,
 	.disable = rockchip_pwm_disable,

@@ -178,6 +243,7 @@ static const struct pwm_ops rockchip_pwm_ops_v1 = {
 };
 
 static const struct pwm_ops rockchip_pwm_ops_v2 = {
+	.get_state = rockchip_pwm_get_state,
 	.config = rockchip_pwm_config,
 	.set_polarity = rockchip_pwm_set_polarity,
 	.enable = rockchip_pwm_enable,

@@ -195,6 +261,7 @@ static const struct rockchip_pwm_data pwm_data_v1 = {
 	.prescaler = 2,
 	.ops = &rockchip_pwm_ops_v1,
 	.set_enable = rockchip_pwm_set_enable_v1,
+	.get_state = rockchip_pwm_get_state_v1,
 };
 
 static const struct rockchip_pwm_data pwm_data_v2 = {

@@ -207,6 +274,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
+	.get_state = rockchip_pwm_get_state_v2,
 };
 
 static const struct rockchip_pwm_data pwm_data_vop = {

@@ -219,6 +287,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
+	.get_state = rockchip_pwm_get_state_v2,
 };
 
 static const struct of_device_id rockchip_pwm_dt_ids[] = {

@@ -882,13 +882,16 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 
 	for (i = 0; i < chip->npwm; i++) {
 		struct pwm_device *pwm = &chip->pwms[i];
+		struct pwm_state pstate;
+
+		pwm_get_state(pwm, &pstate);
 
 		seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
 
 		if (test_bit(PWMF_REQUESTED, &pwm->flags))
 			seq_puts(s, " requested");
 
-		if (pwm_is_enabled(pwm))
+		if (pstate.enabled)
 			seq_puts(s, " enabled");
 
 		seq_puts(s, "\n");

@@ -47,13 +47,13 @@ static ssize_t period_show(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	const struct pwm_device *pwm = export->pwm;
-	unsigned int period;
+	struct pwm_state pstate;
 
 	mutex_lock(&export->lock);
-	period = pwm_get_period(pwm);
+	pwm_get_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%u\n", period);
+	return sprintf(buf, "%u\n", pstate.period);
 }
 
 static ssize_t period_store(struct device *child,

@@ -62,6 +62,7 @@ static ssize_t period_store(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
+	struct pwm_state pstate;
 	unsigned int val;
 	int ret;
 

@@ -70,7 +71,9 @@ static ssize_t period_store(struct device *child,
 		return ret;
 
 	mutex_lock(&export->lock);
-	ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val);
+	pwm_get_state(pwm, &pstate);
+	pstate.period = val;
+	ret = pwm_apply_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
 	return ret ? : size;

@@ -82,13 +85,13 @@ static ssize_t duty_cycle_show(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	const struct pwm_device *pwm = export->pwm;
-	unsigned int duty;
+	struct pwm_state pstate;
 
 	mutex_lock(&export->lock);
-	duty = pwm_get_duty_cycle(pwm);
+	pwm_get_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%u\n", duty);
+	return sprintf(buf, "%u\n", pstate.duty_cycle);
 }
 
 static ssize_t duty_cycle_store(struct device *child,

@@ -97,6 +100,7 @@ static ssize_t duty_cycle_store(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
+	struct pwm_state pstate;
 	unsigned int val;
 	int ret;
 

@@ -105,7 +109,9 @@ static ssize_t duty_cycle_store(struct device *child,
 		return ret;
 
 	mutex_lock(&export->lock);
-	ret = pwm_config(pwm, val, pwm_get_period(pwm));
+	pwm_get_state(pwm, &pstate);
+	pstate.duty_cycle = val;
+	ret = pwm_apply_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
 	return ret ? : size;

@@ -117,13 +123,13 @@ static ssize_t enable_show(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	const struct pwm_device *pwm = export->pwm;
-	bool enabled;
+	struct pwm_state pstate;
 
 	mutex_lock(&export->lock);
-	enabled = pwm_is_enabled(pwm);
+	pwm_get_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%d\n", enabled);
+	return sprintf(buf, "%d\n", pstate.enabled);
 }
 
 static ssize_t enable_store(struct device *child,

@@ -132,24 +138,20 @@ static ssize_t enable_store(struct device *child,
 {
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
+	struct pwm_state pstate;
 	int val, ret;
 
 	ret = kstrtoint(buf, 0, &val);
 	if (ret)
 		return ret;
 
+	if (val != 0 && val != 1)
+		return -EINVAL;
+
 	mutex_lock(&export->lock);
-	switch (val) {
-	case 0:
-		pwm_disable(pwm);
-		break;
-	case 1:
-		ret = pwm_enable(pwm);
-		break;
-	default:
-		ret = -EINVAL;
-		break;
-	}
+	pwm_get_state(pwm, &pstate);
+	pstate.enabled = val;
+	ret = pwm_apply_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
 	return ret ? : size;

@@ -162,9 +164,13 @@ static ssize_t polarity_show(struct device *child,
 	struct pwm_export *export = child_to_pwm_export(child);
 	const struct pwm_device *pwm = export->pwm;
 	const char *polarity = "unknown";
+	struct pwm_state pstate;
 
 	mutex_lock(&export->lock);
-	switch (pwm_get_polarity(pwm)) {
+	pwm_get_state(pwm, &pstate);
+	mutex_unlock(&export->lock);
+
+	switch (pstate.polarity) {
 	case PWM_POLARITY_NORMAL:
 		polarity = "normal";
 		break;

@@ -173,7 +179,6 @@ static ssize_t polarity_show(struct device *child,
 		polarity = "inversed";
 		break;
 	}
-	mutex_unlock(&export->lock);
 
 	return sprintf(buf, "%s\n", polarity);
 }

@@ -185,6 +190,7 @@ static ssize_t polarity_store(struct device *child,
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
 	enum pwm_polarity polarity;
+	struct pwm_state pstate;
 	int ret;
 
 	if (sysfs_streq(buf, "normal"))

@@ -195,7 +201,12 @@ static ssize_t polarity_store(struct device *child,
 		return -EINVAL;
 
 	mutex_lock(&export->lock);
-	ret = pwm_set_polarity(pwm, polarity);
+	pwm_get_state(pwm, &pstate);
+	pstate.polarity = polarity;
+	if (pstate.enabled)
+		ret = -EBUSY;
+	else
+		ret = pwm_apply_state(pwm, &pstate);
 	mutex_unlock(&export->lock);
 
 	return ret ? : size;

@@ -226,6 +226,19 @@ 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)
+{
+	/* driver supports legacy, non-atomic operation */
+	if (ops->config && ops->enable && ops->disable)
+		return true;
+
+	/* driver supports atomic operation */
+	if (ops->apply)
+		return true;
+
+	return false;
+}
+
 /**
  * pwmchip_add_with_polarity() - register a new PWM chip
  * @chip: the PWM chip to add

@@ -244,8 +257,10 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 	unsigned int i;
 	int ret;
 
-	if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
-	    !chip->ops->enable || !chip->ops->disable || !chip->npwm)
+	if (!chip || !chip->dev || !chip->ops || !chip->npwm)
+		return -EINVAL;
+
+	if (!pwm_ops_check(chip->ops))
 		return -EINVAL;
 
 	mutex_lock(&pwm_lock);

@@ -431,102 +446,72 @@ void pwm_free(struct pwm_device *pwm)
 EXPORT_SYMBOL_GPL(pwm_free);
 
 /**
- * pwm_config() - change a PWM device configuration
+ * pwm_apply_state() - atomically apply a new state to a PWM device
  * @pwm: PWM device
- * @duty_ns: "on" time (in nanoseconds)
- * @period_ns: duration (in nanoseconds) of one cycle
- *
- * Returns: 0 on success or a negative error code on failure.
+ * @state: new state to apply. This can be adjusted by the PWM driver
+ *	   if the requested config is not achievable, for example,
+ *	   ->duty_cycle and ->period might be approximated.
  */
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
 {
 	int err;
 
-	if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
-		return -EINVAL;
-
-	err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
-	if (err)
-		return err;
-
-	pwm->state.duty_cycle = duty_ns;
-	pwm->state.period = period_ns;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_config);
-
-/**
- * pwm_set_polarity() - configure the polarity of a PWM signal
- * @pwm: PWM device
- * @polarity: new polarity of the PWM signal
- *
- * Note that the polarity cannot be configured while the PWM device is
- * enabled.
- *
- * Returns: 0 on success or a negative error code on failure.
- */
-int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
-{
-	int err;
-
-	if (!pwm || !pwm->chip->ops)
-		return -EINVAL;
-
-	if (!pwm->chip->ops->set_polarity)
-		return -ENOSYS;
-
-	if (pwm_is_enabled(pwm))
-		return -EBUSY;
-
-	err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
-	if (err)
-		return err;
-
-	pwm->state.polarity = polarity;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_set_polarity);
-
-/**
- * pwm_enable() - start a PWM output toggling
- * @pwm: PWM device
- *
- * Returns: 0 on success or a negative error code on failure.
- */
-int pwm_enable(struct pwm_device *pwm)
-{
-	int err = 0;
-
 	if (!pwm)
 		return -EINVAL;
 
-	if (!pwm_is_enabled(pwm)) {
-		err = pwm->chip->ops->enable(pwm->chip, pwm);
-		if (!err)
-			pwm->state.enabled = true;
-	}
+	if (!memcmp(state, &pwm->state, sizeof(*state)))
+		return 0;
 
-	return err;
-}
-EXPORT_SYMBOL_GPL(pwm_enable);
+	if (pwm->chip->ops->apply) {
+		err = pwm->chip->ops->apply(pwm->chip, pwm, state);
+		if (err)
+			return err;
+	} else {
+		/*
+		 * FIXME: restore the initial state in case of error.
+		 */
+		if (state->polarity != pwm->state.polarity) {
+			if (!pwm->chip->ops->set_polarity)
+				return -ENOTSUPP;
+
+			/*
+			 * Changing the polarity of a running PWM is
+			 * only allowed when the PWM driver implements
+			 * ->apply().
+			 */
+			if (pwm->state.enabled)
+				return -EBUSY;
+
+			err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
+							   state->polarity);
+			if (err)
+				return err;
+		}
 
-/**
- * pwm_disable() - stop a PWM output toggling
- * @pwm: PWM device
- */
-void pwm_disable(struct pwm_device *pwm)
-{
-	if (!pwm)
-		return;
+		if (state->period != pwm->state.period ||
+		    state->duty_cycle != pwm->state.duty_cycle) {
+			err = pwm->chip->ops->config(pwm->chip, pwm,
+						     state->period,
+						     state->duty_cycle);
+			if (err)
+				return err;
+		}
 
-	if (pwm_is_enabled(pwm)) {
-		pwm->chip->ops->disable(pwm->chip, pwm);
-		pwm->state.enabled = false;
+		if (state->enabled != pwm->state.enabled) {
+			if (state->enabled) {
+				err = pwm->chip->ops->enable(pwm->chip, pwm);
+				if (err)
+					return err;
+			} else {
+				pwm->chip->ops->disable(pwm->chip, pwm);
+			}
+		}
 	}
+
+	pwm->state = *state;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(pwm_disable);
+EXPORT_SYMBOL_GPL(pwm_apply_state);
 
 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
 {

@@ -5,59 +5,7 @@
 #include <linux/mutex.h>
 #include <linux/of.h>
 
-struct pwm_device;
 struct seq_file;
-
-#if IS_ENABLED(CONFIG_PWM)
-/*
- * pwm_request - request a PWM device
- */
-struct pwm_device *pwm_request(int pwm_id, const char *label);
-
-/*
- * pwm_free - free a PWM device
- */
-void pwm_free(struct pwm_device *pwm);
-
-/*
- * pwm_config - change a PWM device configuration
- */
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
-
-/*
- * pwm_enable - start a PWM output toggling
- */
-int pwm_enable(struct pwm_device *pwm);
-
-/*
- * pwm_disable - stop a PWM output toggling
- */
-void pwm_disable(struct pwm_device *pwm);
-#else
-static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline void pwm_free(struct pwm_device *pwm)
-{
-}
-
-static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
-{
-	return -EINVAL;
-}
-
-static inline int pwm_enable(struct pwm_device *pwm)
-{
-	return -EINVAL;
-}
-
-static inline void pwm_disable(struct pwm_device *pwm)
-{
-}
-#endif
-
 struct pwm_chip;
 
 /**

@@ -183,11 +131,6 @@ static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
 	return pstate.duty_cycle;
 }
 
-/*
- * pwm_set_polarity - configure the polarity of a PWM signal
- */
-int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
-
 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 {
 	struct pwm_state pstate;

@@ -211,6 +154,10 @@ static inline void pwm_get_args(const struct pwm_device *pwm,
  * @set_polarity: configure the polarity of this PWM
  * @enable: enable PWM output toggling
  * @disable: disable PWM output toggling
+ * @apply: atomically apply a new PWM config. The state argument
+ *	   should be adjusted with the real hardware config (if the
+ *	   approximate the period or duty_cycle value, state should
+ *	   reflect it)
  * @get_state: get the current PWM state. This function is only
  *	       called once per PWM device when the PWM chip is
  *	       registered.

@@ -226,6 +173,8 @@ struct pwm_ops {
 			    enum pwm_polarity polarity);
 	int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
 	void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
+	int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm,
+		     struct pwm_state *state);
 	void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
 			  struct pwm_state *pstate);
 #ifdef CONFIG_DEBUG_FS

@@ -263,6 +212,114 @@ struct pwm_chip {
 };
 
 #if IS_ENABLED(CONFIG_PWM)
+/* PWM user APIs */
+struct pwm_device *pwm_request(int pwm_id, const char *label);
+void pwm_free(struct pwm_device *pwm);
+int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state);
+
+/**
+ * pwm_config() - change a PWM device configuration
+ * @pwm: PWM device
+ * @duty_ns: "on" time (in nanoseconds)
+ * @period_ns: duration (in nanoseconds) of one cycle
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
+			     int period_ns)
+{
+	struct pwm_state pstate;
+
+	if (!pwm)
+		return -EINVAL;
+
+	pwm_get_state(pwm, &pstate);
+	if (pstate.duty_cycle = duty_ns && pstate.period = period_ns)
+		return 0;
+
+	pstate.duty_cycle = duty_ns;
+	pstate.period = period_ns;
+	return pwm_apply_state(pwm, &pstate);
+}
+
+/**
+ * pwm_set_polarity() - configure the polarity of a PWM signal
+ * @pwm: PWM device
+ * @polarity: new polarity of the PWM signal
+ *
+ * Note that the polarity cannot be configured while the PWM device is
+ * enabled.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static inline int pwm_set_polarity(struct pwm_device *pwm,
+				   enum pwm_polarity polarity)
+{
+	struct pwm_state pstate;
+
+	if (!pwm)
+		return -EINVAL;
+
+	pwm_get_state(pwm, &pstate);
+	if (pstate.polarity = polarity)
+		return 0;
+
+	/*
+	 * Changing the polarity of a running PWM without adjusting the
+	 * dutycycle/period value is a bit risky (can introduce glitches).
+	 * Return -EBUSY in this case.
+	 * Note that this is allowed when using pwm_apply_state() because
+	 * the user specifies all the parameters.
+	 */
+	if (pstate.enabled)
+		return -EBUSY;
+
+	pstate.polarity = polarity;
+	return pwm_apply_state(pwm, &pstate);
+}
+
+/**
+ * pwm_enable() - start a PWM output toggling
+ * @pwm: PWM device
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+static inline int pwm_enable(struct pwm_device *pwm)
+{
+	struct pwm_state pstate;
+
+	if (!pwm)
+		return -EINVAL;
+
+	pwm_get_state(pwm, &pstate);
+	if (pstate.enabled)
+		return 0;
+
+	pstate.enabled = true;
+	return pwm_apply_state(pwm, &pstate);
+}
+
+/**
+ * pwm_disable() - stop a PWM output toggling
+ * @pwm: PWM device
+ */
+static inline void pwm_disable(struct pwm_device *pwm)
+{
+	struct pwm_state pstate;
+
+	if (!pwm)
+		return;
+
+	pwm_get_state(pwm, &pstate);
+	if (!pstate.enabled)
+		return;
+
+	pstate.enabled = false;
+	pwm_apply_state(pwm, &pstate);
+}
+
+
+/* PWM provider APIs */
 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 void *pwm_get_chip_data(struct pwm_device *pwm);
 

@@ -288,6 +345,42 @@ void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 
 bool pwm_can_sleep(struct pwm_device *pwm);
 #else
+static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void pwm_free(struct pwm_device *pwm)
+{
+}
+
+static inline int pwm_apply_state(struct pwm_device *pwm,
+				  const struct pwm_state *state)
+{
+	return -ENOTSUPP;
+}
+
+static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
+			     int period_ns)
+{
+	return -EINVAL;
+}
+
+static inline int pwm_set_polarity(struct pwm_device *pwm,
+				   enum pwm_polarity polarity)
+{
+	return -ENOTSUPP;
+}
+
+static inline int pwm_enable(struct pwm_device *pwm)
+{
+	return -EINVAL;
+}
+
+static inline void pwm_disable(struct pwm_device *pwm)
+{
+}
+
 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 {
 	return -EINVAL;

@@ -499,10 +499,10 @@ int pwm_enable(struct pwm_device *pwm)
 	if (!pwm)
 		return -EINVAL;
 
-	if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+	if (!pwm_is_enabled(pwm)) {
 		err = pwm->chip->ops->enable(pwm->chip, pwm);
-		if (err)
-			clear_bit(PWMF_ENABLED, &pwm->flags);
+		if (!err)
+			pwm->state.enabled = true;
 	}
 
 	return err;

@@ -515,8 +515,13 @@ EXPORT_SYMBOL_GPL(pwm_enable);
  */
 void pwm_disable(struct pwm_device *pwm)
 {
-	if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
+	if (!pwm)
+		return;
+
+	if (pwm_is_enabled(pwm)) {
 		pwm->chip->ops->disable(pwm->chip, pwm);
+		pwm->state.enabled = false;
+	}
 }
 EXPORT_SYMBOL_GPL(pwm_disable);
 

@@ -93,8 +93,7 @@ struct pwm_args {
 
 enum {
 	PWMF_REQUESTED = 1 << 0,
-	PWMF_ENABLED = 1 << 1,
-	PWMF_EXPORTED = 1 << 2,
+	PWMF_EXPORTED = 1 << 1,
 };
 
 /*

@@ -102,11 +101,13 @@ enum {
  * @period: PWM period (in nanoseconds)
  * @duty_cycle: PWM duty cycle (in nanoseconds)
  * @polarity: PWM polarity
+ * @enabled: PWM enabled status
  */
 struct pwm_state {
 	unsigned int period;
 	unsigned int duty_cycle;
 	enum pwm_polarity polarity;
+	bool enabled;
 };
 
 /**

@@ -145,7 +146,11 @@ static inline void pwm_get_state(const struct pwm_device *pwm,
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 {
-	return test_bit(PWMF_ENABLED, &pwm->flags);
+	struct pwm_state pstate;
+
+	pwm_get_state(pwm, &pstate);
+
+	return pstate.enabled;
 }
 
 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)

@@ -268,7 +268,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm->chip = chip;
 		pwm->pwm = chip->base + i;
 		pwm->hwpwm = i;
-		pwm->polarity = polarity;
+		pwm->state.polarity = polarity;
 
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}

@@ -446,8 +446,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 	if (err)
 		return err;
 
-	pwm->duty_cycle = duty_ns;
-	pwm->period = period_ns;
+	pwm->state.duty_cycle = duty_ns;
+	pwm->state.period = period_ns;
 
 	return 0;
 }

@@ -480,7 +480,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
 	if (err)
 		return err;
 
-	pwm->polarity = polarity;
+	pwm->state.polarity = polarity;
 
 	return 0;
 }

@@ -97,6 +97,18 @@ enum {
 	PWMF_EXPORTED = 1 << 2,
 };
 
+/*
+ * struct pwm_state - state of a PWM channel
+ * @period: PWM period (in nanoseconds)
+ * @duty_cycle: PWM duty cycle (in nanoseconds)
+ * @polarity: PWM polarity
+ */
+struct pwm_state {
+	unsigned int period;
+	unsigned int duty_cycle;
+	enum pwm_polarity polarity;
+};
+
 /**
  * struct pwm_device - PWM channel object
  * @label: name of the PWM device

@@ -105,10 +117,8 @@ enum {
  * @pwm: global index of the PWM device
  * @chip: PWM chip providing this PWM device
  * @chip_data: chip-private data associated with the PWM device
- * @period: period of the PWM signal (in nanoseconds)
- * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
- * @polarity: polarity of the PWM signal
  * @args: PWM arguments
+ * @state: curent PWM channel state
  */
 struct pwm_device {
 	const char *label;

@@ -118,13 +128,21 @@ struct pwm_device {
 	struct pwm_chip *chip;
 	void *chip_data;
 
-	unsigned int period;
-	unsigned int duty_cycle;
-	enum pwm_polarity polarity;
-
 	struct pwm_args args;
+	struct pwm_state state;
 };
 
+/**
+ * pwm_get_state() - retrieve the current PWM state
+ * @pwm: PWM device
+ * @state: state to fill with the current PWM state
+ */
+static inline void pwm_get_state(const struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	*state = pwm->state;
+}
+
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 {
 	return test_bit(PWMF_ENABLED, &pwm->flags);

@@ -133,23 +151,31 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
 {
 	if (pwm)
-		pwm->period = period;
+		pwm->state.period = period;
 }
 
 static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->period : 0;
+	struct pwm_state pstate;
+
+	pwm_get_state(pwm, &pstate);
+
+	return pstate.period;
 }
 
 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 {
 	if (pwm)
-		pwm->duty_cycle = duty;
+		pwm->state.duty_cycle = duty;
 }
 
 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->duty_cycle : 0;
+	struct pwm_state pstate;
+
+	pwm_get_state(pwm, &pstate);
+
+	return pstate.duty_cycle;
 }
 
 /*

@@ -159,7 +185,11 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
 
 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
+	struct pwm_state pstate;
+
+	pwm_get_state(pwm, &pstate);
+
+	return pstate.polarity;
 }
 
 static inline void pwm_get_args(const struct pwm_device *pwm,

@@ -201,6 +201,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 	struct pwm_bl_data *pb;
 	int initial_blank = FB_BLANK_UNBLANK;
+	struct pwm_args pargs = { };
 	int ret;
 
 	if (!data) {

@@ -312,7 +313,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	 * set the period from platform data if it has not already been set
 	 * via the PWM lookup table.
 	 */
-	pb->period = pwm_get_period(pb->pwm);
+	pwm_get_args(pb->pwm, &pargs);
+	pb->period = pargs.period;
 	if (!pb->period && (data->pwm_period_ns > 0))
 		pb->period = data->pwm_period_ns;
 

@@ -59,16 +59,16 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
 					 unsigned selector)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
-	unsigned int pwm_reg_period;
+	struct pwm_args pargs = { };
 	int dutycycle;
 	int ret;
 
-	pwm_reg_period = pwm_get_period(drvdata->pwm);
+	pwm_get_args(drvdata->pwm, &pargs);
 
-	dutycycle = (pwm_reg_period *
+	dutycycle = (pargs.period *
 		    drvdata->duty_cycle_table[selector].dutycycle) / 100;
 
-	ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period);
+	ret = pwm_config(drvdata->pwm, dutycycle, pargs.period);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM\n");
 		return ret;

@@ -138,13 +138,15 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 	unsigned int ramp_delay = rdev->constraints->ramp_delay;
-	unsigned int period = pwm_get_period(drvdata->pwm);
+	struct pwm_args pargs = { };
 	int duty_cycle;
 	int ret;
 
+	pwm_get_args(drvdata->pwm, &pargs);
 	duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);
 
-	ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period);
+	ret = pwm_config(drvdata->pwm, (pargs.period / 100) * duty_cycle,
+			 pargs.period);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM\n");
 		return ret;

@@ -91,6 +91,7 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 		       struct led_pwm *led, struct device_node *child)
 {
 	struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
+	struct pwm_args pargs = { };
 	int ret;
 
 	led_data->active_low = led->active_low;

@@ -117,7 +118,8 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 	else
 		led_data->cdev.brightness_set_blocking = led_pwm_set_blocking;
 
-	led_data->period = pwm_get_period(led_data->pwm);
+	pwm_get_args(led_data->pwm, &pargs);
+	led_data->period = pargs.period;
 	if (!led_data->period && (led->pwm_period_ns > 0))
 		led_data->period = led->pwm_period_ns;
 

@@ -70,10 +70,13 @@ struct max77693_haptic {
 
 static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
 {
-	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
+	struct pwm_args pargs = { };
+	int delta;
 	int error;
 
-	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
+	pwm_get_args(haptic->pwm_dev, &pargs);
+	delta = (pargs.period + haptic->pwm_duty) / 2;
+	error = pwm_config(haptic->pwm_dev, delta, pargs.period);
 	if (error) {
 		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
 		return error;

@@ -234,6 +237,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
 				       struct ff_effect *effect)
 {
 	struct max77693_haptic *haptic = input_get_drvdata(dev);
+	struct pwm_args pargs = { };
 	u64 period_mag_multi;
 
 	haptic->magnitude = effect->u.rumble.strong_magnitude;

@@ -245,7 +249,8 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
 	 * The formula to convert magnitude to pwm_duty as follows:
 	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
 	 */
-	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
+	pwm_get_args(haptic->pwm_dev, &pargs);
+	period_mag_multi = (u64)pargs.period * haptic->magnitude;
 	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
 						MAX_MAGNITUDE_SHIFT);
 

@@ -75,7 +75,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
 		return -EINVAL;
 	}
 
-	if (pwm->period != period_ns) {
+	if (pwm_get_period(pwm) != period_ns) {
 		int clk_div;
 
 		/* changing the clk divisor, need to disable fisrt */

@@ -249,7 +249,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
 			   LPC18XX_PWM_EVSTATEMSK_ALL);
 
-	if (pwm->polarity = PWM_POLARITY_NORMAL) {
+	if (pwm_get_polarity(pwm) = PWM_POLARITY_NORMAL) {
 		set_event = lpc18xx_pwm->period_event;
 		clear_event = lpc18xx_data->duty_event;
 		res_action = LPC18XX_PWM_RES_SET;

@@ -192,7 +192,7 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
 		load_value, load_value,	match_value, match_value);
 
 	omap->pdata->set_pwm(omap->dm_timer,
-			      pwm->polarity = PWM_POLARITY_INVERSED,
+			      pwm_get_polarity(pwm) = PWM_POLARITY_INVERSED,
 			      true,
 			      PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE);
 

@@ -354,7 +354,8 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 	val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
 	for (i = 0; i < pwm->chip.npwm; i++)
 		if (!(val & BIT_CH(PWM_ACT_STATE, i)))
-			pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
+			pwm_set_polarity(&pwm->chip.pwms[i],
+					 PWM_POLARITY_INVERSED);
 	clk_disable_unprepare(pwm->clk);
 
 	return 0;

@@ -146,12 +146,14 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
-	pwm_set_period(pwm, args->args[1]);
+	pwm->args.period = args->args[1];
+	pwm_set_period(pwm, pwm->args.period);
 
 	if (args->args[2] & PWM_POLARITY_INVERTED)
-		pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
+		pwm->args.polarity = PWM_POLARITY_INVERSED;
 	else
-		pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
+		pwm->args.polarity = PWM_POLARITY_NORMAL;
+	pwm_set_polarity(pwm, pwm->args.polarity);
 
 	return pwm;
 }

@@ -172,7 +174,8 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
-	pwm_set_period(pwm, args->args[1]);
+	pwm->args.period = args->args[1];
+	pwm_set_period(pwm, pwm->args.period);
 
 	return pwm;
 }

@@ -740,6 +743,8 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
 	if (IS_ERR(pwm))
 		goto out;
 
+	pwm->args.period = chosen->period;
+	pwm->args.polarity = chosen->polarity;
 	pwm_set_period(pwm, chosen->period);
 	pwm_set_polarity(pwm, chosen->polarity);
 

@@ -60,7 +60,8 @@ static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 		return -EINVAL;
 
 	/* Store constant period value */
-	pwm_set_period(pwm, DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq));
+	pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
+	pwm_set_period(pwm, pwm->args.period);
 
 	return 0;
 }

@@ -160,6 +160,7 @@ pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
+	pwm->args.period = args->args[0];
 	pwm_set_period(pwm, args->args[0]);
 
 	return pwm;

@@ -74,6 +74,23 @@ enum pwm_polarity {
 	PWM_POLARITY_INVERSED,
 };
 
+/**
+ * struct pwm_args - PWM arguments
+ * @period: reference period
+ * @polarity: reference polarity
+ *
+ * This structure describe board-dependent arguments attached to a PWM
+ * device. Those arguments are usually retrieved from the PWM lookup table or
+ * DT definition.
+ * This should not be confused with the PWM state: PWM args not representing
+ * the current PWM state, but the configuration the PWM user plan to use
+ * on this PWM device.
+ */
+struct pwm_args {
+	unsigned int period;
+	enum pwm_polarity polarity;
+};
+
 enum {
 	PWMF_REQUESTED = 1 << 0,
 	PWMF_ENABLED = 1 << 1,

@@ -91,6 +108,7 @@ enum {
  * @period: period of the PWM signal (in nanoseconds)
  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
  * @polarity: polarity of the PWM signal
+ * @args: PWM arguments
  */
 struct pwm_device {
 	const char *label;

@@ -103,6 +121,8 @@ struct pwm_device {
 	unsigned int period;
 	unsigned int duty_cycle;
 	enum pwm_polarity polarity;
+
+	struct pwm_args args;
 };
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)

@@ -142,6 +162,12 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 	return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
 }
 
+static inline void pwm_get_args(const struct pwm_device *pwm,
+				struct pwm_args *args)
+{
+	*args = pwm->args;
+}
+
 /**
  * struct pwm_ops - PWM controller operations
  * @request: optional hook for requesting a PWM

@@ -269,7 +269,6 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm->pwm = chip->base + i;
 		pwm->hwpwm = i;
 		pwm->polarity = polarity;
-		mutex_init(&pwm->lock);
 
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}

@@ -474,22 +473,16 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
 	if (!pwm->chip->ops->set_polarity)
 		return -ENOSYS;
 
-	mutex_lock(&pwm->lock);
-
-	if (pwm_is_enabled(pwm)) {
-		err = -EBUSY;
-		goto unlock;
-	}
+	if (pwm_is_enabled(pwm))
+		return -EBUSY;
 
 	err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
 	if (err)
-		goto unlock;
+		return err;
 
 	pwm->polarity = polarity;
 
-unlock:
-	mutex_unlock(&pwm->lock);
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pwm_set_polarity);
 

@@ -506,16 +499,12 @@ int pwm_enable(struct pwm_device *pwm)
 	if (!pwm)
 		return -EINVAL;
 
-	mutex_lock(&pwm->lock);
-
 	if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
 		err = pwm->chip->ops->enable(pwm->chip, pwm);
 		if (err)
 			clear_bit(PWMF_ENABLED, &pwm->flags);
 	}
 
-	mutex_unlock(&pwm->lock);
-
 	return err;
 }
 EXPORT_SYMBOL_GPL(pwm_enable);

@@ -26,6 +26,7 @@
 struct pwm_export {
 	struct device child;
 	struct pwm_device *pwm;
+	struct mutex lock;
 };
 
 static struct pwm_export *child_to_pwm_export(struct device *child)

@@ -44,16 +45,23 @@ static ssize_t period_show(struct device *child,
 			   struct device_attribute *attr,
 			   char *buf)
 {
-	const struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	const struct pwm_device *pwm = export->pwm;
+	unsigned int period;
+
+	mutex_lock(&export->lock);
+	period = pwm_get_period(pwm);
+	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%u\n", pwm_get_period(pwm));
+	return sprintf(buf, "%u\n", period);
 }
 
 static ssize_t period_store(struct device *child,
 			    struct device_attribute *attr,
 			    const char *buf, size_t size)
 {
-	struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	struct pwm_device *pwm = export->pwm;
 	unsigned int val;
 	int ret;
 

@@ -61,7 +69,9 @@ static ssize_t period_store(struct device *child,
 	if (ret)
 		return ret;
 
+	mutex_lock(&export->lock);
 	ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val);
+	mutex_unlock(&export->lock);
 
 	return ret ? : size;
 }

@@ -70,16 +80,23 @@ static ssize_t duty_cycle_show(struct device *child,
 			       struct device_attribute *attr,
 			       char *buf)
 {
-	const struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	const struct pwm_device *pwm = export->pwm;
+	unsigned int duty;
+
+	mutex_lock(&export->lock);
+	duty = pwm_get_duty_cycle(pwm);
+	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%u\n", pwm_get_duty_cycle(pwm));
+	return sprintf(buf, "%u\n", duty);
 }
 
 static ssize_t duty_cycle_store(struct device *child,
 				struct device_attribute *attr,
 				const char *buf, size_t size)
 {
-	struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	struct pwm_device *pwm = export->pwm;
 	unsigned int val;
 	int ret;
 

@@ -87,7 +104,9 @@ static ssize_t duty_cycle_store(struct device *child,
 	if (ret)
 		return ret;
 
+	mutex_lock(&export->lock);
 	ret = pwm_config(pwm, val, pwm_get_period(pwm));
+	mutex_unlock(&export->lock);
 
 	return ret ? : size;
 }

@@ -96,22 +115,30 @@ static ssize_t enable_show(struct device *child,
 			   struct device_attribute *attr,
 			   char *buf)
 {
-	const struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	const struct pwm_device *pwm = export->pwm;
+	bool enabled;
+
+	mutex_lock(&export->lock);
+	enabled = pwm_is_enabled(pwm);
+	mutex_unlock(&export->lock);
 
-	return sprintf(buf, "%d\n", pwm_is_enabled(pwm));
+	return sprintf(buf, "%d\n", enabled);
 }
 
 static ssize_t enable_store(struct device *child,
 			    struct device_attribute *attr,
 			    const char *buf, size_t size)
 {
-	struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	struct pwm_device *pwm = export->pwm;
 	int val, ret;
 
 	ret = kstrtoint(buf, 0, &val);
 	if (ret)
 		return ret;
 
+	mutex_lock(&export->lock);
 	switch (val) {
 	case 0:
 		pwm_disable(pwm);

@@ -123,6 +150,7 @@ static ssize_t enable_store(struct device *child,
 		ret = -EINVAL;
 		break;
 	}
+	mutex_unlock(&export->lock);
 
 	return ret ? : size;
 }

@@ -131,9 +159,11 @@ static ssize_t polarity_show(struct device *child,
 			     struct device_attribute *attr,
 			     char *buf)
 {
-	const struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	const struct pwm_device *pwm = export->pwm;
 	const char *polarity = "unknown";
 
+	mutex_lock(&export->lock);
 	switch (pwm_get_polarity(pwm)) {
 	case PWM_POLARITY_NORMAL:
 		polarity = "normal";

@@ -143,6 +173,7 @@ static ssize_t polarity_show(struct device *child,
 		polarity = "inversed";
 		break;
 	}
+	mutex_unlock(&export->lock);
 
 	return sprintf(buf, "%s\n", polarity);
 }

@@ -151,7 +182,8 @@ static ssize_t polarity_store(struct device *child,
 			      struct device_attribute *attr,
 			      const char *buf, size_t size)
 {
-	struct pwm_device *pwm = child_to_pwm_device(child);
+	struct pwm_export *export = child_to_pwm_export(child);
+	struct pwm_device *pwm = export->pwm;
 	enum pwm_polarity polarity;
 	int ret;
 

@@ -162,7 +194,9 @@ static ssize_t polarity_store(struct device *child,
 	else
 		return -EINVAL;
 
+	mutex_lock(&export->lock);
 	ret = pwm_set_polarity(pwm, polarity);
+	mutex_unlock(&export->lock);
 
 	return ret ? : size;
 }

@@ -203,6 +237,7 @@ static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
 	}
 
 	export->pwm = pwm;
+	mutex_init(&export->lock);
 
 	export->child.release = pwm_export_release;
 	export->child.parent = parent;

@@ -88,7 +88,6 @@ enum {
  * @pwm: global index of the PWM device
  * @chip: PWM chip providing this PWM device
  * @chip_data: chip-private data associated with the PWM device
- * @lock: used to serialize accesses to the PWM device where necessary
  * @period: period of the PWM signal (in nanoseconds)
  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
  * @polarity: polarity of the PWM signal

@@ -100,7 +99,6 @@ struct pwm_device {
 	unsigned int pwm;
 	struct pwm_chip *chip;
 	void *chip_data;
-	struct mutex lock;
 
 	unsigned int period;
 	unsigned int duty_cycle;

@@ -162,7 +162,7 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 
 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pwm_get_period(pchip->pwmd);
+	unsigned int period = pchip->pdata->pwm_period;
 	unsigned int duty = br * period / br_max;
 
 	pwm_config(pchip->pwmd, duty, period);

@@ -425,7 +425,6 @@ static int lm3630a_probe(struct i2c_client *client,
 			return PTR_ERR(pchip->pwmd);
 		}
 	}
-	pchip->pwmd->period = pdata->pwm_period;
 
 	/* interrupt enable  : irq 0 is not allowed */
 	pchip->irq = client->irq;