Merge tag 'pwm/for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "The changes this time around are mostly janitorial in nature. A lot of
  this is simplifications of drivers using device-managed functions and
  improving compilation coverage.

  The Mediatek display PWM driver now supports the atomic API.

  Cleanups and minor fixes make up the remainder of this set"

* tag 'pwm/for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (54 commits)
  pwm: mtk-disp: Implement atomic API .get_state()
  pwm: mtk-disp: Fix overflow in period and duty calculation
  pwm: mtk-disp: Implement atomic API .apply()
  pwm: mtk-disp: Adjust the clocks to avoid them mismatch
  dt-bindings: pwm: rockchip: Add description for rk3568
  pwm: Make pwmchip_remove() return void
  pwm: sun4i: Don't check the return code of pwmchip_remove()
  pwm: sifive: Don't check the return code of pwmchip_remove()
  pwm: samsung: Don't check the return code of pwmchip_remove()
  pwm: renesas-tpu: Don't check the return code of pwmchip_remove()
  pwm: rcar: Don't check the return code of pwmchip_remove()
  pwm: pca9685: Don't check the return code of pwmchip_remove()
  pwm: omap-dmtimer: Don't check the return code of pwmchip_remove()
  pwm: mtk-disp: Don't check the return code of pwmchip_remove()
  pwm: imx-tpm: Don't check the return code of pwmchip_remove()
  pwm: img: Don't check the return code of pwmchip_remove()
  pwm: cros-ec: Don't check the return code of pwmchip_remove()
  pwm: brcmstb: Don't check the return code of pwmchip_remove()
  pwm: atmel-tcb: Don't check the return code of pwmchip_remove()
  pwm: atmel-hlcdc: Don't check the return code of pwmchip_remove()
  ...

43 files changed, 260 insertions, 440 deletions

diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml b/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml
index 5596bee70509..81a54a4e8e3e 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml
@@ -29,6 +29,7 @@ properties:
           - enum:
               - rockchip,px30-pwm
               - rockchip,rk3308-pwm
+              - rockchip,rk3568-pwm
           - const: rockchip,rk3328-pwm
 
   reg:
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index c76adedd58c9..aa29841bbb79 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -272,7 +272,7 @@ config PWM_IQS620A
 
 config PWM_JZ4740
 	tristate "Ingenic JZ47xx PWM support"
-	depends on MIPS
+	depends on MIPS || COMPILE_TEST
 	depends on COMMON_CLK
 	select MFD_SYSCON
 	help
@@ -284,7 +284,8 @@ config PWM_JZ4740
 
 config PWM_KEEMBAY
 	tristate "Intel Keem Bay PWM driver"
-	depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST)
+	depends on ARCH_KEEMBAY || COMPILE_TEST
+	depends on COMMON_CLK && HAS_IOMEM
 	help
 	  The platform driver for Intel Keem Bay PWM controller.
 
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 35e894f4a379..4527f09a5c50 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -304,7 +304,7 @@ EXPORT_SYMBOL_GPL(pwmchip_add);
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-int pwmchip_remove(struct pwm_chip *chip)
+void pwmchip_remove(struct pwm_chip *chip)
 {
 	pwmchip_sysfs_unexport(chip);
 
@@ -318,8 +318,6 @@ int pwmchip_remove(struct pwm_chip *chip)
 	free_pwms(chip);
 
 	mutex_unlock(&pwm_lock);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(pwmchip_remove);
 
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
index e2a26d9da25b..ad37bc46f272 100644
--- a/drivers/pwm/pwm-ab8500.c
+++ b/drivers/pwm/pwm-ab8500.c
@@ -22,14 +22,21 @@
 
 struct ab8500_pwm_chip {
 	struct pwm_chip chip;
+	unsigned int hwid;
 };
 
+static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct ab8500_pwm_chip, chip);
+}
+
 static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			    const struct pwm_state *state)
 {
 	int ret;
 	u8 reg;
 	unsigned int higher_val, lower_val;
+	struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
 
 	if (state->polarity != PWM_POLARITY_NORMAL)
 		return -EINVAL;
@@ -37,7 +44,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (!state->enabled) {
 		ret = abx500_mask_and_set_register_interruptible(chip->dev,
 					AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
-					1 << (chip->base - 1), 0);
+					1 << ab8500->hwid, 0);
 
 		if (ret < 0)
 			dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
@@ -56,7 +63,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	 */
 	higher_val = ((state->duty_cycle & 0x0300) >> 8);
 
-	reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2);
+	reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2);
 
 	ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
 			reg, (u8)lower_val);
@@ -70,7 +77,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	ret = abx500_mask_and_set_register_interruptible(chip->dev,
 				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
-				1 << (chip->base - 1), 1 << (chip->base - 1));
+				1 << ab8500->hwid, 1 << ab8500->hwid);
 	if (ret < 0)
 		dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
 							pwm->label, ret);
@@ -88,6 +95,9 @@ static int ab8500_pwm_probe(struct platform_device *pdev)
 	struct ab8500_pwm_chip *ab8500;
 	int err;
 
+	if (pdev->id < 1 || pdev->id > 31)
+		return dev_err_probe(&pdev->dev, EINVAL, "Invalid device id %d\n", pdev->id);
+
 	/*
 	 * Nothing to be done in probe, this is required to get the
 	 * device which is required for ab8500 read and write
@@ -99,27 +109,13 @@ static int ab8500_pwm_probe(struct platform_device *pdev)
 	ab8500->chip.dev = &pdev->dev;
 	ab8500->chip.ops = &ab8500_pwm_ops;
 	ab8500->chip.npwm = 1;
+	ab8500->hwid = pdev->id - 1;
 
-	err = pwmchip_add(&ab8500->chip);
+	err = devm_pwmchip_add(&pdev->dev, &ab8500->chip);
 	if (err < 0)
 		return dev_err_probe(&pdev->dev, err, "Failed to add pwm chip\n");
 
 	dev_dbg(&pdev->dev, "pwm probe successful\n");
-	platform_set_drvdata(pdev, ab8500);
-
-	return 0;
-}
-
-static int ab8500_pwm_remove(struct platform_device *pdev)
-{
-	struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
-	int err;
-
-	err = pwmchip_remove(&ab8500->chip);
-	if (err < 0)
-		return err;
-
-	dev_dbg(&pdev->dev, "pwm driver removed\n");
 
 	return 0;
 }
@@ -129,7 +125,6 @@ static struct platform_driver ab8500_pwm_driver = {
 		.name = "ab8500-pwm",
 	},
 	.probe = ab8500_pwm_probe,
-	.remove = ab8500_pwm_remove,
 };
 module_platform_driver(ab8500_pwm_driver);
 
diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
index 4459325d3650..a43b2babc809 100644
--- a/drivers/pwm/pwm-atmel-hlcdc.c
+++ b/drivers/pwm/pwm-atmel-hlcdc.c
@@ -281,11 +281,8 @@ static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
 static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
 {
 	struct atmel_hlcdc_pwm *chip = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&chip->chip);
-	if (ret)
-		return ret;
+	pwmchip_remove(&chip->chip);
 
 	clk_disable_unprepare(chip->hlcdc->periph_clk);
 
diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
index bf398f21484d..36f7ea381838 100644
--- a/drivers/pwm/pwm-atmel-tcb.c
+++ b/drivers/pwm/pwm-atmel-tcb.c
@@ -503,11 +503,8 @@ err_slow_clk:
 static int atmel_tcb_pwm_remove(struct platform_device *pdev)
 {
 	struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
-	int err;
 
-	err = pwmchip_remove(&tcbpwm->chip);
-	if (err < 0)
-		return err;
+	pwmchip_remove(&tcbpwm->chip);
 
 	clk_disable_unprepare(tcbpwm->slow_clk);
 	clk_put(tcbpwm->slow_clk);
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index a8162bae3e8a..e748604403cc 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -84,9 +84,19 @@ struct atmel_pwm_chip {
 	void __iomem *base;
 	const struct atmel_pwm_data *data;
 
-	unsigned int updated_pwms;
-	/* ISR is cleared when read, ensure only one thread does that */
-	struct mutex isr_lock;
+	/*
+	 * The hardware supports a mechanism to update a channel's duty cycle at
+	 * the end of the currently running period. When such an update is
+	 * pending we delay disabling the PWM until the new configuration is
+	 * active because otherwise pmw_config(duty_cycle=0); pwm_disable();
+	 * might not result in an inactive output.
+	 * This bitmask tracks for which channels an update is pending in
+	 * hardware.
+	 */
+	u32 update_pending;
+
+	/* Protects .update_pending */
+	spinlock_t lock;
 };
 
 static inline struct atmel_pwm_chip *to_atmel_pwm_chip(struct pwm_chip *chip)
@@ -123,6 +133,64 @@ static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip,
 	atmel_pwm_writel(chip, base + offset, val);
 }
 
+static void atmel_pwm_update_pending(struct atmel_pwm_chip *chip)
+{
+	/*
+	 * Each channel that has its bit in ISR set started a new period since
+	 * ISR was cleared and so there is no more update pending.  Note that
+	 * reading ISR clears it, so this needs to handle all channels to not
+	 * loose information.
+	 */
+	u32 isr = atmel_pwm_readl(chip, PWM_ISR);
+
+	chip->update_pending &= ~isr;
+}
+
+static void atmel_pwm_set_pending(struct atmel_pwm_chip *chip, unsigned int ch)
+{
+	spin_lock(&chip->lock);
+
+	/*
+	 * Clear pending flags in hardware because otherwise there might still
+	 * be a stale flag in ISR.
+	 */
+	atmel_pwm_update_pending(chip);
+
+	chip->update_pending |= (1 << ch);
+
+	spin_unlock(&chip->lock);
+}
+
+static int atmel_pwm_test_pending(struct atmel_pwm_chip *chip, unsigned int ch)
+{
+	int ret = 0;
+
+	spin_lock(&chip->lock);
+
+	if (chip->update_pending & (1 << ch)) {
+		atmel_pwm_update_pending(chip);
+
+		if (chip->update_pending & (1 << ch))
+			ret = 1;
+	}
+
+	spin_unlock(&chip->lock);
+
+	return ret;
+}
+
+static int atmel_pwm_wait_nonpending(struct atmel_pwm_chip *chip, unsigned int ch)
+{
+	unsigned long timeout = jiffies + 2 * HZ;
+	int ret;
+
+	while ((ret = atmel_pwm_test_pending(chip, ch)) &&
+	       time_before(jiffies, timeout))
+		usleep_range(10, 100);
+
+	return ret ? -ETIMEDOUT : 0;
+}
+
 static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
 					     unsigned long clkrate,
 					     const struct pwm_state *state,
@@ -185,6 +253,7 @@ static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
 			    atmel_pwm->data->regs.duty_upd, cdty);
+	atmel_pwm_set_pending(atmel_pwm, pwm->hwpwm);
 }
 
 static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
@@ -205,20 +274,8 @@ static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 	unsigned long timeout = jiffies + 2 * HZ;
 
-	/*
-	 * Wait for at least a complete period to have passed before disabling a
-	 * channel to be sure that CDTY has been updated
-	 */
-	mutex_lock(&atmel_pwm->isr_lock);
-	atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
-
-	while (!(atmel_pwm->updated_pwms & (1 << pwm->hwpwm)) &&
-	       time_before(jiffies, timeout)) {
-		usleep_range(10, 100);
-		atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
-	}
+	atmel_pwm_wait_nonpending(atmel_pwm, pwm->hwpwm);
 
-	mutex_unlock(&atmel_pwm->isr_lock);
 	atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);
 
 	/*
@@ -292,10 +349,6 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			val |= PWM_CMR_CPOL;
 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
 		atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);
-		mutex_lock(&atmel_pwm->isr_lock);
-		atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
-		atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
-		mutex_unlock(&atmel_pwm->isr_lock);
 		atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
 	} else if (cstate.enabled) {
 		atmel_pwm_disable(chip, pwm, true);
@@ -326,6 +379,9 @@ static void atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 		tmp <<= pres;
 		state->period = DIV64_U64_ROUND_UP(tmp, rate);
 
+		/* Wait for an updated duty_cycle queued in hardware */
+		atmel_pwm_wait_nonpending(atmel_pwm, pwm->hwpwm);
+
 		cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
 					  atmel_pwm->data->regs.duty);
 		tmp = (u64)(cprd - cdty) * NSEC_PER_SEC;
@@ -416,9 +472,10 @@ static int atmel_pwm_probe(struct platform_device *pdev)
 	if (!atmel_pwm)
 		return -ENOMEM;
 
-	mutex_init(&atmel_pwm->isr_lock);
 	atmel_pwm->data = of_device_get_match_data(&pdev->dev);
-	atmel_pwm->updated_pwms = 0;
+
+	atmel_pwm->update_pending = 0;
+	spin_lock_init(&atmel_pwm->lock);
 
 	atmel_pwm->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(atmel_pwm->base))
@@ -460,7 +517,6 @@ static int atmel_pwm_remove(struct platform_device *pdev)
 	pwmchip_remove(&atmel_pwm->chip);
 
 	clk_unprepare(atmel_pwm->clk);
-	mutex_destroy(&atmel_pwm->isr_lock);
 
 	return 0;
 }
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index 8c85c66ea5c9..64148f5f81d0 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -267,8 +267,6 @@ static int kona_pwmc_probe(struct platform_device *pdev)
 	if (kp == NULL)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, kp);
-
 	kp->chip.dev = &pdev->dev;
 	kp->chip.ops = &kona_pwm_ops;
 	kp->chip.npwm = 6;
@@ -298,20 +296,13 @@ static int kona_pwmc_probe(struct platform_device *pdev)
 
 	clk_disable_unprepare(kp->clk);
 
-	ret = pwmchip_add(&kp->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &kp->chip);
 	if (ret < 0)
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 
 	return ret;
 }
 
-static int kona_pwmc_remove(struct platform_device *pdev)
-{
-	struct kona_pwmc *kp = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&kp->chip);
-}
-
 static const struct of_device_id bcm_kona_pwmc_dt[] = {
 	{ .compatible = "brcm,kona-pwm" },
 	{ },
@@ -324,7 +315,6 @@ static struct platform_driver kona_pwmc_driver = {
 		.of_match_table = bcm_kona_pwmc_dt,
 	},
 	.probe = kona_pwmc_probe,
-	.remove = kona_pwmc_remove,
 };
 module_platform_driver(kona_pwmc_driver);
 
diff --git a/drivers/pwm/pwm-brcmstb.c b/drivers/pwm/pwm-brcmstb.c
index 8b1d1e7aa856..3b529f82b97c 100644
--- a/drivers/pwm/pwm-brcmstb.c
+++ b/drivers/pwm/pwm-brcmstb.c
@@ -282,12 +282,11 @@ out_clk:
 static int brcmstb_pwm_remove(struct platform_device *pdev)
 {
 	struct brcmstb_pwm *p = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&p->chip);
+	pwmchip_remove(&p->chip);
 	clk_disable_unprepare(p->clk);
 
-	return ret;
+	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 9fffb566af5f..5e29d9c682c3 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -280,7 +280,9 @@ static int cros_ec_pwm_remove(struct platform_device *dev)
 	struct cros_ec_pwm_device *ec_pwm = platform_get_drvdata(dev);
 	struct pwm_chip *chip = &ec_pwm->chip;
 
-	return pwmchip_remove(chip);
+	pwmchip_remove(chip);
+
+	return 0;
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/pwm/pwm-ep93xx.c b/drivers/pwm/pwm-ep93xx.c
index fc3cb7d669c6..c45a75e65c86 100644
--- a/drivers/pwm/pwm-ep93xx.c
+++ b/drivers/pwm/pwm-ep93xx.c
@@ -183,27 +183,18 @@ static int ep93xx_pwm_probe(struct platform_device *pdev)
 	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
 	ep93xx_pwm->chip.npwm = 1;
 
-	ret = pwmchip_add(&ep93xx_pwm->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &ep93xx_pwm->chip);
 	if (ret < 0)
 		return ret;
 
-	platform_set_drvdata(pdev, ep93xx_pwm);
 	return 0;
 }
 
-static int ep93xx_pwm_remove(struct platform_device *pdev)
-{
-	struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&ep93xx_pwm->chip);
-}
-
 static struct platform_driver ep93xx_pwm_driver = {
 	.driver = {
 		.name = "ep93xx-pwm",
 	},
 	.probe = ep93xx_pwm_probe,
-	.remove = ep93xx_pwm_remove,
 };
 module_platform_driver(ep93xx_pwm_driver);
 
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
index 96ccd772280c..0247757f9a72 100644
--- a/drivers/pwm/pwm-fsl-ftm.c
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -453,7 +453,7 @@ static int fsl_pwm_probe(struct platform_device *pdev)
 	fpc->chip.ops = &fsl_pwm_ops;
 	fpc->chip.npwm = 8;
 
-	ret = pwmchip_add(&fpc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &fpc->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 		return ret;
@@ -464,13 +464,6 @@ static int fsl_pwm_probe(struct platform_device *pdev)
 	return fsl_pwm_init(fpc);
 }
 
-static int fsl_pwm_remove(struct platform_device *pdev)
-{
-	struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&fpc->chip);
-}
-
 #ifdef CONFIG_PM_SLEEP
 static int fsl_pwm_suspend(struct device *dev)
 {
@@ -552,7 +545,6 @@ static struct platform_driver fsl_pwm_driver = {
 		.pm = &fsl_pwm_pm_ops,
 	},
 	.probe = fsl_pwm_probe,
-	.remove = fsl_pwm_remove,
 };
 module_platform_driver(fsl_pwm_driver);
 
diff --git a/drivers/pwm/pwm-hibvt.c b/drivers/pwm/pwm-hibvt.c
index 4a6e9ad3c0ff..333f1b18ff4e 100644
--- a/drivers/pwm/pwm-hibvt.c
+++ b/drivers/pwm/pwm-hibvt.c
@@ -248,13 +248,15 @@ static int hibvt_pwm_remove(struct platform_device *pdev)
 
 	pwm_chip = platform_get_drvdata(pdev);
 
+	pwmchip_remove(&pwm_chip->chip);
+
 	reset_control_assert(pwm_chip->rstc);
 	msleep(30);
 	reset_control_deassert(pwm_chip->rstc);
 
 	clk_disable_unprepare(pwm_chip->clk);
 
-	return pwmchip_remove(&pwm_chip->chip);
+	return 0;
 }
 
 static const struct of_device_id hibvt_pwm_of_match[] = {
diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index 11b16ecc4f96..f97f82548293 100644
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c
@@ -326,28 +326,14 @@ err_pm_disable:
 static int img_pwm_remove(struct platform_device *pdev)
 {
 	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);
-	u32 val;
-	unsigned int i;
-	int ret;
-
-	ret = pm_runtime_get_sync(&pdev->dev);
-	if (ret < 0) {
-		pm_runtime_put(&pdev->dev);
-		return ret;
-	}
-
-	for (i = 0; i < pwm_chip->chip.npwm; i++) {
-		val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
-		val &= ~BIT(i);
-		img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
-	}
 
-	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		img_pwm_runtime_suspend(&pdev->dev);
 
-	return pwmchip_remove(&pwm_chip->chip);
+	pwmchip_remove(&pwm_chip->chip);
+
+	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index dbb50493abdd..e5e7b7c339a8 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -382,11 +382,12 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev)
 static int pwm_imx_tpm_remove(struct platform_device *pdev)
 {
 	struct imx_tpm_pwm_chip *tpm = platform_get_drvdata(pdev);
-	int ret = pwmchip_remove(&tpm->chip);
+
+	pwmchip_remove(&tpm->chip);
 
 	clk_disable_unprepare(tpm->clk);
 
-	return ret;
+	return 0;
 }
 
 static int __maybe_unused pwm_imx_tpm_suspend(struct device *dev)
diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index f6588a96fbd9..ea91a2f81a9f 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -313,8 +313,6 @@ static int pwm_imx27_probe(struct platform_device *pdev)
 	if (imx == NULL)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, imx);
-
 	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
 	if (IS_ERR(imx->clk_ipg))
 		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_ipg),
@@ -342,16 +340,7 @@ static int pwm_imx27_probe(struct platform_device *pdev)
 	if (!(pwmcr & MX3_PWMCR_EN))
 		pwm_imx27_clk_disable_unprepare(imx);
 
-	return pwmchip_add(&imx->chip);
-}
-
-static int pwm_imx27_remove(struct platform_device *pdev)
-{
-	struct pwm_imx27_chip *imx;
-
-	imx = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&imx->chip);
+	return devm_pwmchip_add(&pdev->dev, &imx->chip);
 }
 
 static struct platform_driver imx_pwm_driver = {
@@ -360,7 +349,6 @@ static struct platform_driver imx_pwm_driver = {
 		.of_match_table = pwm_imx27_dt_ids,
 	},
 	.probe = pwm_imx27_probe,
-	.remove = pwm_imx27_remove,
 };
 module_platform_driver(imx_pwm_driver);
 
diff --git a/drivers/pwm/pwm-intel-lgm.c b/drivers/pwm/pwm-intel-lgm.c
index 015f5eba09a1..b66c35074087 100644
--- a/drivers/pwm/pwm-intel-lgm.c
+++ b/drivers/pwm/pwm-intel-lgm.c
@@ -176,8 +176,6 @@ static int lgm_pwm_probe(struct platform_device *pdev)
 	if (!pc)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, pc);
-
 	io_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(io_base))
 		return PTR_ERR(io_base);
@@ -210,20 +208,13 @@ static int lgm_pwm_probe(struct platform_device *pdev)
 
 	lgm_pwm_init(pc);
 
-	ret = pwmchip_add(&pc->chip);
+	ret = devm_pwmchip_add(dev, &pc->chip);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "failed to add PWM chip\n");
 
 	return 0;
 }
 
-static int lgm_pwm_remove(struct platform_device *pdev)
-{
-	struct lgm_pwm_chip *pc = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&pc->chip);
-}
-
 static const struct of_device_id lgm_pwm_of_match[] = {
 	{ .compatible = "intel,lgm-pwm" },
 	{ }
@@ -236,7 +227,6 @@ static struct platform_driver lgm_pwm_driver = {
 		.of_match_table = lgm_pwm_of_match,
 	},
 	.probe = lgm_pwm_probe,
-	.remove = lgm_pwm_remove,
 };
 module_platform_driver(lgm_pwm_driver);
 
diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c
index 6c6e26d18329..54bd95a5cab0 100644
--- a/drivers/pwm/pwm-iqs620a.c
+++ b/drivers/pwm/pwm-iqs620a.c
@@ -189,7 +189,6 @@ static int iqs620_pwm_probe(struct platform_device *pdev)
 	if (!iqs620_pwm)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, iqs620_pwm);
 	iqs620_pwm->iqs62x = iqs62x;
 
 	ret = regmap_read(iqs62x->regmap, IQS620_PWR_SETTINGS, &val);
@@ -224,31 +223,18 @@ static int iqs620_pwm_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = pwmchip_add(&iqs620_pwm->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &iqs620_pwm->chip);
 	if (ret)
 		dev_err(&pdev->dev, "Failed to add device: %d\n", ret);
 
 	return ret;
 }
 
-static int iqs620_pwm_remove(struct platform_device *pdev)
-{
-	struct iqs620_pwm_private *iqs620_pwm = platform_get_drvdata(pdev);
-	int ret;
-
-	ret = pwmchip_remove(&iqs620_pwm->chip);
-	if (ret)
-		dev_err(&pdev->dev, "Failed to remove device: %d\n", ret);
-
-	return ret;
-}
-
 static struct platform_driver iqs620_pwm_platform_driver = {
 	.driver = {
 		.name = "iqs620a-pwm",
 	},
 	.probe = iqs620_pwm_probe,
-	.remove = iqs620_pwm_remove,
 };
 module_platform_driver(iqs620_pwm_platform_driver);
 
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index 990e7904c7f1..23dc1fb770e2 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -245,16 +245,7 @@ static int jz4740_pwm_probe(struct platform_device *pdev)
 	jz4740->chip.ops = &jz4740_pwm_ops;
 	jz4740->chip.npwm = info->num_pwms;
 
-	platform_set_drvdata(pdev, jz4740);
-
-	return pwmchip_add(&jz4740->chip);
-}
-
-static int jz4740_pwm_remove(struct platform_device *pdev)
-{
-	struct jz4740_pwm_chip *jz4740 = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&jz4740->chip);
+	return devm_pwmchip_add(dev, &jz4740->chip);
 }
 
 static const struct soc_info __maybe_unused jz4740_soc_info = {
@@ -280,7 +271,6 @@ static struct platform_driver jz4740_pwm_driver = {
 		.of_match_table = of_match_ptr(jz4740_pwm_dt_ids),
 	},
 	.probe = jz4740_pwm_probe,
-	.remove = jz4740_pwm_remove,
 };
 module_platform_driver(jz4740_pwm_driver);
 
diff --git a/drivers/pwm/pwm-keembay.c b/drivers/pwm/pwm-keembay.c
index 521a825c8ba0..733811b05721 100644
--- a/drivers/pwm/pwm-keembay.c
+++ b/drivers/pwm/pwm-keembay.c
@@ -207,22 +207,13 @@ static int keembay_pwm_probe(struct platform_device *pdev)
 	priv->chip.ops = &keembay_pwm_ops;
 	priv->chip.npwm = KMB_TOTAL_PWM_CHANNELS;
 
-	ret = pwmchip_add(&priv->chip);
+	ret = devm_pwmchip_add(dev, &priv->chip);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
 
-	platform_set_drvdata(pdev, priv);
-
 	return 0;
 }
 
-static int keembay_pwm_remove(struct platform_device *pdev)
-{
-	struct keembay_pwm *priv = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&priv->chip);
-}
-
 static const struct of_device_id keembay_pwm_of_match[] = {
 	{ .compatible = "intel,keembay-pwm" },
 	{ }
@@ -231,7 +222,6 @@ MODULE_DEVICE_TABLE(of, keembay_pwm_of_match);
 
 static struct platform_driver keembay_pwm_driver = {
 	.probe	= keembay_pwm_probe,
-	.remove	= keembay_pwm_remove,
 	.driver	= {
 		.name = "pwm-keembay",
 		.of_match_table = keembay_pwm_of_match,
diff --git a/drivers/pwm/pwm-lp3943.c b/drivers/pwm/pwm-lp3943.c
index 7551253ada32..ea17d446a627 100644
--- a/drivers/pwm/pwm-lp3943.c
+++ b/drivers/pwm/pwm-lp3943.c
@@ -276,16 +276,7 @@ static int lp3943_pwm_probe(struct platform_device *pdev)
 	lp3943_pwm->chip.ops = &lp3943_pwm_ops;
 	lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
 
-	platform_set_drvdata(pdev, lp3943_pwm);
-
-	return pwmchip_add(&lp3943_pwm->chip);
-}
-
-static int lp3943_pwm_remove(struct platform_device *pdev)
-{
-	struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&lp3943_pwm->chip);
+	return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->chip);
 }
 
 #ifdef CONFIG_OF
@@ -298,7 +289,6 @@ MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
 
 static struct platform_driver lp3943_pwm_driver = {
 	.probe = lp3943_pwm_probe,
-	.remove = lp3943_pwm_remove,
 	.driver = {
 		.name = "lp3943-pwm",
 		.of_match_table = of_match_ptr(lp3943_pwm_of_match),
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index 2834a0f001d3..ddeab5687cb8 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -117,29 +117,20 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
 	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
 	lpc32xx->chip.npwm = 1;
 
-	ret = pwmchip_add(&lpc32xx->chip);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
-		return ret;
-	}
-
-	/* When PWM is disable, configure the output to the default value */
+	/* If PWM is disabled, configure the output to the default value */
 	val = readl(lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
 	val &= ~PWM_PIN_LEVEL;
 	writel(val, lpc32xx->base + (lpc32xx->chip.pwms[0].hwpwm << 2));
 
-	platform_set_drvdata(pdev, lpc32xx);
+	ret = devm_pwmchip_add(&pdev->dev, &lpc32xx->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
+		return ret;
+	}
 
 	return 0;
 }
 
-static int lpc32xx_pwm_remove(struct platform_device *pdev)
-{
-	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&lpc32xx->chip);
-}
-
 static const struct of_device_id lpc32xx_pwm_dt_ids[] = {
 	{ .compatible = "nxp,lpc3220-pwm", },
 	{ /* sentinel */ }
@@ -152,7 +143,6 @@ static struct platform_driver lpc32xx_pwm_driver = {
 		.of_match_table = lpc32xx_pwm_dt_ids,
 	},
 	.probe = lpc32xx_pwm_probe,
-	.remove = lpc32xx_pwm_remove,
 };
 module_platform_driver(lpc32xx_pwm_driver);
 
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index b4a31060bcd7..0d4dd80e9f07 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -253,13 +253,11 @@ static int pwm_mediatek_probe(struct platform_device *pdev)
 		}
 	}
 
-	platform_set_drvdata(pdev, pc);
-
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &pwm_mediatek_ops;
 	pc->chip.npwm = pc->soc->num_pwms;
 
-	ret = pwmchip_add(&pc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 		return ret;
@@ -268,13 +266,6 @@ static int pwm_mediatek_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int pwm_mediatek_remove(struct platform_device *pdev)
-{
-	struct pwm_mediatek_chip *pc = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&pc->chip);
-}
-
 static const struct pwm_mediatek_of_data mt2712_pwm_data = {
 	.num_pwms = 8,
 	.pwm45_fixup = false,
@@ -335,7 +326,6 @@ static struct platform_driver pwm_mediatek_driver = {
 		.of_match_table = pwm_mediatek_of_match,
 	},
 	.probe = pwm_mediatek_probe,
-	.remove = pwm_mediatek_remove,
 };
 module_platform_driver(pwm_mediatek_driver);
 
diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 9b3ba401a3db..c605013e4114 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -5,6 +5,7 @@
  * Author: YH Huang <yh.huang@mediatek.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/io.h>
@@ -47,6 +48,7 @@ struct mtk_disp_pwm {
 	struct clk *clk_main;
 	struct clk *clk_mm;
 	void __iomem *base;
+	bool enabled;
 };
 
 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
@@ -66,14 +68,47 @@ static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
 	writel(value, address);
 }
 
-static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
-			       int duty_ns, int period_ns)
+static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 	u32 clk_div, period, high_width, value;
 	u64 div, rate;
 	int err;
 
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+					 0x0);
+
+		if (mdp->enabled) {
+			clk_disable_unprepare(mdp->clk_mm);
+			clk_disable_unprepare(mdp->clk_main);
+		}
+
+		mdp->enabled = false;
+		return 0;
+	}
+
+	if (!mdp->enabled) {
+		err = clk_prepare_enable(mdp->clk_main);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n",
+				ERR_PTR(err));
+			return err;
+		}
+
+		err = clk_prepare_enable(mdp->clk_mm);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n",
+				ERR_PTR(err));
+			clk_disable_unprepare(mdp->clk_main);
+			return err;
+		}
+	}
+
 	/*
 	 * Find period, high_width and clk_div to suit duty_ns and period_ns.
 	 * Calculate proper div value to keep period value in the bound.
@@ -85,29 +120,24 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
 	 */
 	rate = clk_get_rate(mdp->clk_main);
-	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
+	clk_div = mul_u64_u64_div_u64(state->period, rate, NSEC_PER_SEC) >>
 			  PWM_PERIOD_BIT_WIDTH;
-	if (clk_div > PWM_CLKDIV_MAX)
+	if (clk_div > PWM_CLKDIV_MAX) {
+		if (!mdp->enabled) {
+			clk_disable_unprepare(mdp->clk_mm);
+			clk_disable_unprepare(mdp->clk_main);
+		}
 		return -EINVAL;
+	}
 
 	div = NSEC_PER_SEC * (clk_div + 1);
-	period = div64_u64(rate * period_ns, div);
+	period = mul_u64_u64_div_u64(state->period, rate, div);
 	if (period > 0)
 		period--;
 
-	high_width = div64_u64(rate * duty_ns, div);
+	high_width = mul_u64_u64_div_u64(state->duty_cycle, rate, div);
 	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
 
-	err = clk_enable(mdp->clk_main);
-	if (err < 0)
-		return err;
-
-	err = clk_enable(mdp->clk_mm);
-	if (err < 0) {
-		clk_disable(mdp->clk_main);
-		return err;
-	}
-
 	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
 				 PWM_CLKDIV_MASK,
 				 clk_div << PWM_CLKDIV_SHIFT);
@@ -122,50 +152,70 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
 					 mdp->data->commit_mask,
 					 0x0);
+	} else {
+		/*
+		 * For MT2701, disable double buffer before writing register
+		 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
+		 */
+		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
+					 mdp->data->bls_debug_mask,
+					 mdp->data->bls_debug_mask);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+					 mdp->data->con0_sel,
+					 mdp->data->con0_sel);
 	}
 
-	clk_disable(mdp->clk_mm);
-	clk_disable(mdp->clk_main);
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+				 mdp->data->enable_mask);
+	mdp->enabled = true;
 
 	return 0;
 }
 
-static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
+				   struct pwm_device *pwm,
+				   struct pwm_state *state)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
+	u64 rate, period, high_width;
+	u32 clk_div, con0, con1;
 	int err;
 
-	err = clk_enable(mdp->clk_main);
-	if (err < 0)
-		return err;
-
-	err = clk_enable(mdp->clk_mm);
+	err = clk_prepare_enable(mdp->clk_main);
 	if (err < 0) {
-		clk_disable(mdp->clk_main);
-		return err;
+		dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err));
+		return;
 	}
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
-				 mdp->data->enable_mask);
-
-	return 0;
-}
-
-static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
-
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
-				 0x0);
+	err = clk_prepare_enable(mdp->clk_mm);
+	if (err < 0) {
+		dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err));
+		clk_disable_unprepare(mdp->clk_main);
+		return;
+	}
 
-	clk_disable(mdp->clk_mm);
-	clk_disable(mdp->clk_main);
+	rate = clk_get_rate(mdp->clk_main);
+	con0 = readl(mdp->base + mdp->data->con0);
+	con1 = readl(mdp->base + mdp->data->con1);
+	state->enabled = !!(con0 & BIT(0));
+	clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
+	period = FIELD_GET(PWM_PERIOD_MASK, con1);
+	/*
+	 * period has 12 bits, clk_div 11 and NSEC_PER_SEC has 30,
+	 * so period * (clk_div + 1) * NSEC_PER_SEC doesn't overflow.
+	 */
+	state->period = DIV64_U64_ROUND_UP(period * (clk_div + 1) * NSEC_PER_SEC, rate);
+	high_width = FIELD_GET(PWM_HIGH_WIDTH_MASK, con1);
+	state->duty_cycle = DIV64_U64_ROUND_UP(high_width * (clk_div + 1) * NSEC_PER_SEC,
+					       rate);
+	state->polarity = PWM_POLARITY_NORMAL;
+	clk_disable_unprepare(mdp->clk_mm);
+	clk_disable_unprepare(mdp->clk_main);
 }
 
 static const struct pwm_ops mtk_disp_pwm_ops = {
-	.config = mtk_disp_pwm_config,
-	.enable = mtk_disp_pwm_enable,
-	.disable = mtk_disp_pwm_disable,
+	.apply = mtk_disp_pwm_apply,
+	.get_state = mtk_disp_pwm_get_state,
 	.owner = THIS_MODULE,
 };
 
@@ -192,58 +242,28 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(mdp->clk_mm))
 		return PTR_ERR(mdp->clk_mm);
 
-	ret = clk_prepare(mdp->clk_main);
-	if (ret < 0)
-		return ret;
-
-	ret = clk_prepare(mdp->clk_mm);
-	if (ret < 0)
-		goto disable_clk_main;
-
 	mdp->chip.dev = &pdev->dev;
 	mdp->chip.ops = &mtk_disp_pwm_ops;
 	mdp->chip.npwm = 1;
 
 	ret = pwmchip_add(&mdp->chip);
 	if (ret < 0) {
-		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
-		goto disable_clk_mm;
+		dev_err(&pdev->dev, "pwmchip_add() failed: %pe\n", ERR_PTR(ret));
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, mdp);
 
-	/*
-	 * For MT2701, disable double buffer before writing register
-	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
-	 */
-	if (!mdp->data->has_commit) {
-		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
-					 mdp->data->bls_debug_mask,
-					 mdp->data->bls_debug_mask);
-		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
-					 mdp->data->con0_sel,
-					 mdp->data->con0_sel);
-	}
-
 	return 0;
-
-disable_clk_mm:
-	clk_unprepare(mdp->clk_mm);
-disable_clk_main:
-	clk_unprepare(mdp->clk_main);
-	return ret;
 }
 
 static int mtk_disp_pwm_remove(struct platform_device *pdev)
 {
 	struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&mdp->chip);
-	clk_unprepare(mdp->clk_mm);
-	clk_unprepare(mdp->clk_main);
+	pwmchip_remove(&mdp->chip);
 
-	return ret;
+	return 0;
 }
 
 static const struct mtk_pwm_data mt2701_pwm_data = {
diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
index a22180803bd7..766dbc58dad8 100644
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -145,30 +145,18 @@ static int mxs_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = pwmchip_add(&mxs->chip);
+	/* FIXME: Only do this if the PWM isn't already running */
+	ret = stmp_reset_block(mxs->base);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "failed to reset PWM\n");
+
+	ret = devm_pwmchip_add(&pdev->dev, &mxs->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, mxs);
-
-	ret = stmp_reset_block(mxs->base);
-	if (ret)
-		goto pwm_remove;
-
 	return 0;
-
-pwm_remove:
-	pwmchip_remove(&mxs->chip);
-	return ret;
-}
-
-static int mxs_pwm_remove(struct platform_device *pdev)
-{
-	struct mxs_pwm_chip *mxs = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&mxs->chip);
 }
 
 static const struct of_device_id mxs_pwm_dt_ids[] = {
@@ -183,7 +171,6 @@ static struct platform_driver mxs_pwm_driver = {
 		.of_match_table = mxs_pwm_dt_ids,
 	},
 	.probe = mxs_pwm_probe,
-	.remove = mxs_pwm_remove,
 };
 module_platform_driver(mxs_pwm_driver);
 
diff --git a/drivers/pwm/pwm-ntxec.c b/drivers/pwm/pwm-ntxec.c
index 50c454c553c4..ab63b081df53 100644
--- a/drivers/pwm/pwm-ntxec.c
+++ b/drivers/pwm/pwm-ntxec.c
@@ -150,23 +150,12 @@ static int ntxec_pwm_probe(struct platform_device *pdev)
 	priv->ec = ec;
 	priv->dev = &pdev->dev;
 
-	platform_set_drvdata(pdev, priv);
-
 	chip = &priv->chip;
 	chip->dev = &pdev->dev;
 	chip->ops = &ntxec_pwm_ops;
-	chip->base = -1;
 	chip->npwm = 1;
 
-	return pwmchip_add(chip);
-}
-
-static int ntxec_pwm_remove(struct platform_device *pdev)
-{
-	struct ntxec_pwm *priv = platform_get_drvdata(pdev);
-	struct pwm_chip *chip = &priv->chip;
-
-	return pwmchip_remove(chip);
+	return devm_pwmchip_add(&pdev->dev, chip);
 }
 
 static struct platform_driver ntxec_pwm_driver = {
@@ -174,7 +163,6 @@ static struct platform_driver ntxec_pwm_driver = {
 		.name = "ntxec-pwm",
 	},
 	.probe = ntxec_pwm_probe,
-	.remove = ntxec_pwm_remove,
 };
 module_platform_driver(ntxec_pwm_driver);
 
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 507a2d945b90..fa800fcf31d4 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -444,11 +444,8 @@ err_find_timer_pdev:
 static int pwm_omap_dmtimer_remove(struct platform_device *pdev)
 {
 	struct pwm_omap_dmtimer_chip *omap = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&omap->chip);
-	if (ret)
-		return ret;
+	pwmchip_remove(&omap->chip);
 
 	if (pm_runtime_active(&omap->dm_timer_pdev->dev))
 		omap->pdata->stop(omap->dm_timer);
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 42ed770b432c..c56001a790d0 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -601,11 +601,8 @@ static int pca9685_pwm_probe(struct i2c_client *client,
 static int pca9685_pwm_remove(struct i2c_client *client)
 {
 	struct pca9685 *pca = i2c_get_clientdata(client);
-	int ret;
 
-	ret = pwmchip_remove(&pca->chip);
-	if (ret)
-		return ret;
+	pwmchip_remove(&pca->chip);
 
 	if (!pm_runtime_enabled(&client->dev)) {
 		/* Put chip in sleep state if runtime PM is disabled */
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index e091a528e33c..a9efdcf839ae 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -195,32 +195,21 @@ static int pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pc->mmio_base))
 		return PTR_ERR(pc->mmio_base);
 
-	ret = pwmchip_add(&pc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, pc);
 	return 0;
 }
 
-static int pwm_remove(struct platform_device *pdev)
-{
-	struct pxa_pwm_chip *pc;
-
-	pc = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&pc->chip);
-}
-
 static struct platform_driver pwm_driver = {
 	.driver		= {
 		.name	= "pxa25x-pwm",
 		.of_match_table = pwm_of_match,
 	},
 	.probe		= pwm_probe,
-	.remove		= pwm_remove,
 	.id_table	= pwm_id_table,
 };
 
diff --git a/drivers/pwm/pwm-raspberrypi-poe.c b/drivers/pwm/pwm-raspberrypi-poe.c
index 043fc32e8be8..579a15240e0a 100644
--- a/drivers/pwm/pwm-raspberrypi-poe.c
+++ b/drivers/pwm/pwm-raspberrypi-poe.c
@@ -166,8 +166,6 @@ static int raspberrypi_pwm_probe(struct platform_device *pdev)
 	rpipwm->chip.base = -1;
 	rpipwm->chip.npwm = RASPBERRYPI_FIRMWARE_PWM_NUM;
 
-	platform_set_drvdata(pdev, rpipwm);
-
 	ret = raspberrypi_pwm_get_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG,
 					   &rpipwm->duty_cycle);
 	if (ret) {
@@ -175,14 +173,7 @@ static int raspberrypi_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	return pwmchip_add(&rpipwm->chip);
-}
-
-static int raspberrypi_pwm_remove(struct platform_device *pdev)
-{
-	struct raspberrypi_pwm *rpipwm = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&rpipwm->chip);
+	return devm_pwmchip_add(dev, &rpipwm->chip);
 }
 
 static const struct of_device_id raspberrypi_pwm_of_match[] = {
@@ -197,7 +188,6 @@ static struct platform_driver raspberrypi_pwm_driver = {
 		.of_match_table = raspberrypi_pwm_of_match,
 	},
 	.probe = raspberrypi_pwm_probe,
-	.remove = raspberrypi_pwm_remove,
 };
 module_platform_driver(raspberrypi_pwm_driver);
 
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 9daca0c772c7..b437192380e2 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -241,13 +241,12 @@ static int rcar_pwm_probe(struct platform_device *pdev)
 static int rcar_pwm_remove(struct platform_device *pdev)
 {
 	struct rcar_pwm_chip *rcar_pwm = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&rcar_pwm->chip);
+	pwmchip_remove(&rcar_pwm->chip);
 
 	pm_runtime_disable(&pdev->dev);
 
-	return ret;
+	return 0;
 }
 
 static const struct of_device_id rcar_pwm_of_table[] = {
diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c
index b853e7942605..4381df90a527 100644
--- a/drivers/pwm/pwm-renesas-tpu.c
+++ b/drivers/pwm/pwm-renesas-tpu.c
@@ -425,13 +425,12 @@ static int tpu_probe(struct platform_device *pdev)
 static int tpu_remove(struct platform_device *pdev)
 {
 	struct tpu_device *tpu = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&tpu->chip);
+	pwmchip_remove(&tpu->chip);
 
 	pm_runtime_disable(&pdev->dev);
 
-	return ret;
+	return 0;
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index cbe900877724..f3647b317152 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -384,24 +384,12 @@ static int rockchip_pwm_remove(struct platform_device *pdev)
 {
 	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
 
-	/*
-	 * 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().
-	 *
-	 */
-	if (pwm_is_enabled(pc->chip.pwms))
-		clk_disable(pc->clk);
+	pwmchip_remove(&pc->chip);
 
 	clk_unprepare(pc->pclk);
 	clk_unprepare(pc->clk);
 
-	return pwmchip_remove(&pc->chip);
+	return 0;
 }
 
 static struct platform_driver rockchip_pwm_driver = {
diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
index f6c528f02d43..dd94c4312a0c 100644
--- a/drivers/pwm/pwm-samsung.c
+++ b/drivers/pwm/pwm-samsung.c
@@ -580,11 +580,8 @@ static int pwm_samsung_probe(struct platform_device *pdev)
 static int pwm_samsung_remove(struct platform_device *pdev)
 {
 	struct samsung_pwm_chip *chip = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&chip->chip);
-	if (ret < 0)
-		return ret;
+	pwmchip_remove(&chip->chip);
 
 	clk_disable_unprepare(chip->base_clk);
 
diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
index 420edc4aa94a..253c4a17d255 100644
--- a/drivers/pwm/pwm-sifive.c
+++ b/drivers/pwm/pwm-sifive.c
@@ -291,7 +291,7 @@ static int pwm_sifive_remove(struct platform_device *dev)
 	struct pwm_sifive_ddata *ddata = platform_get_drvdata(dev);
 	bool is_enabled = false;
 	struct pwm_device *pwm;
-	int ret, ch;
+	int ch;
 
 	for (ch = 0; ch < ddata->chip.npwm; ch++) {
 		pwm = &ddata->chip.pwms[ch];
@@ -304,10 +304,10 @@ static int pwm_sifive_remove(struct platform_device *dev)
 		clk_disable(ddata->clk);
 
 	clk_disable_unprepare(ddata->clk);
-	ret = pwmchip_remove(&ddata->chip);
+	pwmchip_remove(&ddata->chip);
 	clk_notifier_unregister(ddata->clk, &ddata->notifier);
 
-	return ret;
+	return 0;
 }
 
 static const struct of_device_id pwm_sifive_of_match[] = {
diff --git a/drivers/pwm/pwm-sl28cpld.c b/drivers/pwm/pwm-sl28cpld.c
index 7a69c1a0c060..589aeaaa6ac8 100644
--- a/drivers/pwm/pwm-sl28cpld.c
+++ b/drivers/pwm/pwm-sl28cpld.c
@@ -231,9 +231,7 @@ static int sl28cpld_pwm_probe(struct platform_device *pdev)
 	chip->ops = &sl28cpld_pwm_ops;
 	chip->npwm = 1;
 
-	platform_set_drvdata(pdev, priv);
-
-	ret = pwmchip_add(&priv->pwm_chip);
+	ret = devm_pwmchip_add(&pdev->dev, &priv->pwm_chip);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to add PWM chip (%pe)",
 			ERR_PTR(ret));
@@ -243,13 +241,6 @@ static int sl28cpld_pwm_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int sl28cpld_pwm_remove(struct platform_device *pdev)
-{
-	struct sl28cpld_pwm *priv = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&priv->pwm_chip);
-}
-
 static const struct of_device_id sl28cpld_pwm_of_match[] = {
 	{ .compatible = "kontron,sl28cpld-pwm" },
 	{}
@@ -258,7 +249,6 @@ MODULE_DEVICE_TABLE(of, sl28cpld_pwm_of_match);
 
 static struct platform_driver sl28cpld_pwm_driver = {
 	.probe = sl28cpld_pwm_probe,
-	.remove	= sl28cpld_pwm_remove,
 	.driver = {
 		.name = "sl28cpld-pwm",
 		.of_match_table = sl28cpld_pwm_of_match,
diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 93dd03618465..3115abb3f52a 100644
--- a/drivers/pwm/pwm-stm32-lp.c
+++ b/drivers/pwm/pwm-stm32-lp.c
@@ -209,7 +209,7 @@ static int stm32_pwm_lp_probe(struct platform_device *pdev)
 	priv->chip.ops = &stm32_pwm_lp_ops;
 	priv->chip.npwm = 1;
 
-	ret = pwmchip_add(&priv->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &priv->chip);
 	if (ret < 0)
 		return ret;
 
@@ -218,15 +218,6 @@ static int stm32_pwm_lp_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int stm32_pwm_lp_remove(struct platform_device *pdev)
-{
-	struct stm32_pwm_lp *priv = platform_get_drvdata(pdev);
-
-	pwm_disable(&priv->chip.pwms[0]);
-
-	return pwmchip_remove(&priv->chip);
-}
-
 static int __maybe_unused stm32_pwm_lp_suspend(struct device *dev)
 {
 	struct stm32_pwm_lp *priv = dev_get_drvdata(dev);
@@ -258,7 +249,6 @@ MODULE_DEVICE_TABLE(of, stm32_pwm_lp_of_match);
 
 static struct platform_driver stm32_pwm_lp_driver = {
 	.probe	= stm32_pwm_lp_probe,
-	.remove	= stm32_pwm_lp_remove,
 	.driver	= {
 		.name = "stm32-pwm-lp",
 		.of_match_table = of_match_ptr(stm32_pwm_lp_of_match),
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index c952604e91f3..91ca67651abd 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -484,11 +484,8 @@ err_bus:
 static int sun4i_pwm_remove(struct platform_device *pdev)
 {
 	struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = pwmchip_remove(&pwm->chip);
-	if (ret)
-		return ret;
+	pwmchip_remove(&pwm->chip);
 
 	clk_disable_unprepare(pwm->bus_clk);
 	reset_control_assert(pwm->rst);
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 35eb19a5a0d1..4701f0c9b921 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -253,7 +253,7 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pc->mmio_base))
 		return PTR_ERR(pc->mmio_base);
 
-	ret = pwmchip_add(&pc->chip);
+	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 		return ret;
@@ -267,11 +267,9 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 
 static int ecap_pwm_remove(struct platform_device *pdev)
 {
-	struct ecap_pwm_chip *pc = platform_get_drvdata(pdev);
-
 	pm_runtime_disable(&pdev->dev);
 
-	return pwmchip_remove(&pc->chip);
+	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 17909fa53211..5b723a48c5f1 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -485,11 +485,13 @@ static int ehrpwm_pwm_remove(struct platform_device *pdev)
 {
 	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
 
+	pwmchip_remove(&pc->chip);
+
 	clk_unprepare(pc->tbclk);
 
 	pm_runtime_disable(&pdev->dev);
 
-	return pwmchip_remove(&pc->chip);
+	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/pwm/pwm-twl-led.c b/drivers/pwm/pwm-twl-led.c
index 6c8df5f4e87d..49d9f7a78012 100644
--- a/drivers/pwm/pwm-twl-led.c
+++ b/drivers/pwm/pwm-twl-led.c
@@ -276,7 +276,6 @@ static const struct pwm_ops twl6030_pwmled_ops = {
 static int twl_pwmled_probe(struct platform_device *pdev)
 {
 	struct twl_pwmled_chip *twl;
-	int ret;
 
 	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 	if (!twl)
@@ -294,20 +293,7 @@ static int twl_pwmled_probe(struct platform_device *pdev)
 
 	mutex_init(&twl->mutex);
 
-	ret = pwmchip_add(&twl->chip);
-	if (ret < 0)
-		return ret;
-
-	platform_set_drvdata(pdev, twl);
-
-	return 0;
-}
-
-static int twl_pwmled_remove(struct platform_device *pdev)
-{
-	struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&twl->chip);
+	return devm_pwmchip_add(&pdev->dev, &twl->chip);
 }
 
 #ifdef CONFIG_OF
@@ -325,7 +311,6 @@ static struct platform_driver twl_pwmled_driver = {
 		.of_match_table = of_match_ptr(twl_pwmled_of_match),
 	},
 	.probe = twl_pwmled_probe,
-	.remove = twl_pwmled_remove,
 };
 module_platform_driver(twl_pwmled_driver);
 
diff --git a/drivers/pwm/pwm-twl.c b/drivers/pwm/pwm-twl.c
index e83a826bf621..203194f2c92e 100644
--- a/drivers/pwm/pwm-twl.c
+++ b/drivers/pwm/pwm-twl.c
@@ -298,7 +298,6 @@ static const struct pwm_ops twl6030_pwm_ops = {
 static int twl_pwm_probe(struct platform_device *pdev)
 {
 	struct twl_pwm_chip *twl;
-	int ret;
 
 	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 	if (!twl)
@@ -314,20 +313,7 @@ static int twl_pwm_probe(struct platform_device *pdev)
 
 	mutex_init(&twl->mutex);
 
-	ret = pwmchip_add(&twl->chip);
-	if (ret < 0)
-		return ret;
-
-	platform_set_drvdata(pdev, twl);
-
-	return 0;
-}
-
-static int twl_pwm_remove(struct platform_device *pdev)
-{
-	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
-
-	return pwmchip_remove(&twl->chip);
+	return devm_pwmchip_add(&pdev->dev, &twl->chip);
 }
 
 #ifdef CONFIG_OF
@@ -345,7 +331,6 @@ static struct platform_driver twl_pwm_driver = {
 		.of_match_table = of_match_ptr(twl_pwm_of_match),
 	},
 	.probe = twl_pwm_probe,
-	.remove = twl_pwm_remove,
 };
 module_platform_driver(twl_pwm_driver);
 
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index a0b7e43049d5..725c9b784e60 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -404,7 +404,7 @@ int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 void *pwm_get_chip_data(struct pwm_device *pwm);
 
 int pwmchip_add(struct pwm_chip *chip);
-int pwmchip_remove(struct pwm_chip *chip);
+void pwmchip_remove(struct pwm_chip *chip);
 
 int devm_pwmchip_add(struct device *dev, struct pwm_chip *chip);