Merge tag 'pwm/for-4.9-rc1' of...

Merge tag 'pwm/for-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set of changes contains support for PWM signal capture in the STi
  driver as well as support for the PWM controller found on Meson SoCs.
  There's also support added for the MediaTek MT2701 and SunXi H3 to the
  existing drivers.

  Other than that there's a fair set of miscellaneous cleanups and fixes
  across the board"

* tag 'pwm/for-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (24 commits)
  pwm: meson: Handle unknown ID values
  pwm: sti: Take the opportunity to conduct a little house keeping
  pwm: sti: It's now valid for number of PWM channels to be zero
  pwm: sti: Add PWM capture callback
  pwm: sti: Add support for PWM capture interrupts
  pwm: sti: Initialise PWM capture device data
  pwm: sti: Supply PWM Capture clock handling
  pwm: sti: Supply PWM capture register addresses and bit locations
  pwm: sti: Only request clock rate when needed
  pwm: sti: Reorganise register names in preparation for new functionality
  pwm: sti: Rename channel => device
  dt-bindings: pwm: sti: Update DT bindings for capture support
  pwm: lpc-18xx: use pwm_set_chip_data
  pwm: sunxi: Add H3 support
  pwm: Add support for Meson PWM Controller
  dt-bindings: pwm: Add bindings for Meson PWM Controller
  pwm: samsung: Fix to use lowest div for large enough modulation bits
  pwm: pwm-tipwmss: Remove all runtime PM gets/puts
  pwm: cros-ec: Add __packed to prevent padding
  pwm: Add MediaTek MT2701 display PWM driver support
  ...

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

+Amlogic Meson PWM Controller
+============================
+
+Required properties:
+- compatible: Shall contain "amlogic,meson8b-pwm" or "amlogic,meson-gxbb-pwm".
+- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+  the cells format.
+
+Optional properties:
+- clocks: Could contain one or two parents clocks phandle for each of the two
+  PWM channels.
+- clock-names: Could contain at least the "clkin0" and/or "clkin1" names.
+
+Example:
+
+	pwm_ab: pwm@8550 {
+		compatible = "amlogic,meson-gxbb-pwm";
+		reg = <0x0 0x08550 0x0 0x10>;
+		#pwm-cells = <3>;
+		status = "disabled";
+		clocks = <&xtal>, <&xtal>;
+		clock-names = "clkin0", "clkin1";
+	}

Documentation/devicetree/bindings/pwm/pwm-mtk-disp.txt

@@ -2,8 +2,9 @@ MediaTek display PWM controller
 
 Required properties:
  - compatible: should be "mediatek,<name>-disp-pwm":
-   - "mediatek,mt8173-disp-pwm": found on mt8173 SoC.
+   - "mediatek,mt2701-disp-pwm": found on mt2701 SoC.
    - "mediatek,mt6595-disp-pwm": found on mt6595 SoC.
+   - "mediatek,mt8173-disp-pwm": found on mt8173 SoC.
  - reg: physical base address and length of the controller's registers.
  - #pwm-cells: must be 2. See pwm.txt in this directory for a description of
    the cell format.

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

@@ -13,13 +13,14 @@ Required parameters:
 - pinctrl-0: 		List of phandles pointing to pin configuration nodes
 			for PWM module.
 			For Pinctrl properties, please refer to [1].
-- clock-names: 		Set to "pwm".
+- clock-names: 		Valid entries are "pwm" and/or "capture".
 - clocks: 		phandle of the clock used by the PWM module.
 			For Clk properties, please refer to [2].
+- interrupts:		IRQ for the Capture device
 
 Optional properties:
-- st,pwm-num-chan:	Number of available channels. If not passed, the driver
-			will consider single channel by default.
+- st,pwm-num-chan:	Number of available PWM channels.  Default is 0.
+- st,capture-num-chan:	Number of available Capture channels.  Default is 0.
 
 [1] Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
 [2] Documentation/devicetree/bindings/clock/clock-bindings.txt
@@ -38,4 +39,5 @@ pwm1: pwm@fe510000 {
 	clocks = <&clk_sysin>;
 	clock-names = "pwm";
 	st,pwm-num-chan = <4>;
+	st,capture-num-chan = <2>;
 };

Documentation/devicetree/bindings/pwm/pwm-sun4i.txt

@@ -6,6 +6,7 @@ Required properties:
     - "allwinner,sun5i-a10s-pwm"
     - "allwinner,sun5i-a13-pwm"
     - "allwinner,sun7i-a20-pwm"
+    - "allwinner,sun8i-h3-pwm"
   - reg: physical base address and length of the controller's registers
   - #pwm-cells: should be 3. See pwm.txt in this directory for a description of
     the cells format.

drivers/pwm/Kconfig

@@ -262,6 +262,15 @@ config PWM_LPSS_PLATFORM
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-lpss-platform.
 
+config PWM_MESON
+	tristate "Amlogic Meson PWM driver"
+	depends on ARCH_MESON
+	help
+	  The platform driver for Amlogic Meson PWM controller.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-meson.
+
 config PWM_MTK_DISP
 	tristate "MediaTek display PWM driver"
 	depends on ARCH_MEDIATEK || COMPILE_TEST

drivers/pwm/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o
 obj-$(CONFIG_PWM_LPSS)		+= pwm-lpss.o
 obj-$(CONFIG_PWM_LPSS_PCI)	+= pwm-lpss-pci.o
 obj-$(CONFIG_PWM_LPSS_PLATFORM)	+= pwm-lpss-platform.o
+obj-$(CONFIG_PWM_MESON)		+= pwm-meson.o
 obj-$(CONFIG_PWM_MTK_DISP)	+= pwm-mtk-disp.o
 obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
 obj-$(CONFIG_PWM_OMAP_DMTIMER)	+= pwm-omap-dmtimer.o

drivers/pwm/core.c

@@ -339,6 +339,8 @@ int pwmchip_remove(struct pwm_chip *chip)
 	unsigned int i;
 	int ret = 0;
 
+	pwmchip_sysfs_unexport_children(chip);
+
 	mutex_lock(&pwm_lock);
 
 	for (i = 0; i < chip->npwm; i++) {

drivers/pwm/pwm-berlin.c

@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
+#include <linux/slab.h>
 
 #define BERLIN_PWM_EN			0x0
 #define  BERLIN_PWM_ENABLE		BIT(0)
@@ -27,6 +28,13 @@
 #define BERLIN_PWM_TCNT			0xc
 #define  BERLIN_PWM_MAX_TCNT		65535
 
+struct berlin_pwm_channel {
+	u32 enable;
+	u32 ctrl;
+	u32 duty;
+	u32 tcnt;
+};
+
 struct berlin_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
@@ -55,6 +63,25 @@ static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
 	writel_relaxed(value, chip->base + channel * 0x10 + offset);
 }
 
+static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct berlin_pwm_channel *channel;
+
+	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
+	if (!channel)
+		return -ENOMEM;
+
+	return pwm_set_chip_data(pwm, channel);
+}
+
+static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);
+
+	pwm_set_chip_data(pwm, NULL);
+	kfree(channel);
+}
+
 static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
 			     int duty_ns, int period_ns)
 {
@@ -137,6 +164,8 @@ static void berlin_pwm_disable(struct pwm_chip *chip,
 }
 
 static const struct pwm_ops berlin_pwm_ops = {
+	.request = berlin_pwm_request,
+	.free = berlin_pwm_free,
 	.config = berlin_pwm_config,
 	.set_polarity = berlin_pwm_set_polarity,
 	.enable = berlin_pwm_enable,
@@ -204,12 +233,67 @@ static int berlin_pwm_remove(struct platform_device *pdev)
 	return ret;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int berlin_pwm_suspend(struct device *dev)
+{
+	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+	unsigned int i;
+
+	for (i = 0; i < pwm->chip.npwm; i++) {
+		struct berlin_pwm_channel *channel;
+
+		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
+		if (!channel)
+			continue;
+
+		channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
+		channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
+		channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
+		channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
+	}
+
+	clk_disable_unprepare(pwm->clk);
+
+	return 0;
+}
+
+static int berlin_pwm_resume(struct device *dev)
+{
+	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+	unsigned int i;
+	int ret;
+
+	ret = clk_prepare_enable(pwm->clk);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < pwm->chip.npwm; i++) {
+		struct berlin_pwm_channel *channel;
+
+		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
+		if (!channel)
+			continue;
+
+		berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
+		berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
+		berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
+		berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
+			 berlin_pwm_resume);
+
 static struct platform_driver berlin_pwm_driver = {
 	.probe = berlin_pwm_probe,
 	.remove = berlin_pwm_remove,
 	.driver = {
 		.name = "berlin-pwm",
 		.of_match_table = berlin_pwm_match,
+		.pm = &berlin_pwm_pm_ops,
 	},
 };
 module_platform_driver(berlin_pwm_driver);

drivers/pwm/pwm-cros-ec.c

@@ -38,7 +38,7 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
 	struct {
 		struct cros_ec_command msg;
 		struct ec_params_pwm_set_duty params;
-	} buf;
+	} __packed buf;
 	struct ec_params_pwm_set_duty *params = &buf.params;
 	struct cros_ec_command *msg = &buf.msg;
 
@@ -65,7 +65,7 @@ static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index,
 			struct ec_params_pwm_get_duty params;
 			struct ec_response_pwm_get_duty resp;
 		};
-	} buf;
+	} __packed buf;
 	struct ec_params_pwm_get_duty *params = &buf.params;
 	struct ec_response_pwm_get_duty *resp = &buf.resp;
 	struct cros_ec_command *msg = &buf.msg;

drivers/pwm/pwm-lpc18xx-sct.c

@@ -413,14 +413,18 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
+		struct lpc18xx_pwm_data *data;
+
 		pwm = &lpc18xx_pwm->chip.pwms[i];
-		pwm->chip_data = devm_kzalloc(lpc18xx_pwm->dev,
-					      sizeof(struct lpc18xx_pwm_data),
-					      GFP_KERNEL);
-		if (!pwm->chip_data) {
+
+		data = devm_kzalloc(lpc18xx_pwm->dev, sizeof(*data),
+				    GFP_KERNEL);
+		if (!data) {
 			ret = -ENOMEM;
 			goto remove_pwmchip;
 		}
+
+		pwm_set_chip_data(pwm, data);
 	}
 
 	platform_set_drvdata(pdev, lpc18xx_pwm);

drivers/pwm/pwm-mtk-disp.c

@@ -18,30 +18,40 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
 
 #define DISP_PWM_EN		0x00
-#define PWM_ENABLE_MASK		BIT(0)
 
-#define DISP_PWM_COMMIT		0x08
-#define PWM_COMMIT_MASK		BIT(0)
-
-#define DISP_PWM_CON_0		0x10
 #define PWM_CLKDIV_SHIFT	16
 #define PWM_CLKDIV_MAX		0x3ff
 #define PWM_CLKDIV_MASK		(PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
 
-#define DISP_PWM_CON_1		0x14
 #define PWM_PERIOD_BIT_WIDTH	12
 #define PWM_PERIOD_MASK		((1 << PWM_PERIOD_BIT_WIDTH) - 1)
 
 #define PWM_HIGH_WIDTH_SHIFT	16
 #define PWM_HIGH_WIDTH_MASK	(0x1fff << PWM_HIGH_WIDTH_SHIFT)
 
+struct mtk_pwm_data {
+	u32 enable_mask;
+	unsigned int con0;
+	u32 con0_sel;
+	unsigned int con1;
+
+	bool has_commit;
+	unsigned int commit;
+	unsigned int commit_mask;
+
+	unsigned int bls_debug;
+	u32 bls_debug_mask;
+};
+
 struct mtk_disp_pwm {
 	struct pwm_chip chip;
+	const struct mtk_pwm_data *data;
 	struct clk *clk_main;
 	struct clk *clk_mm;
 	void __iomem *base;
@@ -106,12 +116,21 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return err;
 	}
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_0, PWM_CLKDIV_MASK,
+	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+				 PWM_CLKDIV_MASK,
 				 clk_div << PWM_CLKDIV_SHIFT);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_1,
-				 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, value);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 1);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 0);
+	mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
+				 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
+				 value);
+
+	if (mdp->data->has_commit) {
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
+					 mdp->data->commit_mask,
+					 mdp->data->commit_mask);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
+					 mdp->data->commit_mask,
+					 0x0);
+	}
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -134,7 +153,8 @@ static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 		return err;
 	}
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, PWM_ENABLE_MASK, 1);
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+				 mdp->data->enable_mask);
 
 	return 0;
 }
@@ -143,7 +163,8 @@ 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, PWM_ENABLE_MASK, 0);
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+				 0x0);
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -166,6 +187,8 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	if (!mdp)
 		return -ENOMEM;
 
+	mdp->data = of_device_get_match_data(&pdev->dev);
+
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	mdp->base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(mdp->base))
@@ -200,6 +223,19 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 
 	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:
@@ -221,9 +257,30 @@ static int mtk_disp_pwm_remove(struct platform_device *pdev)
 	return ret;
 }
 
+static const struct mtk_pwm_data mt2701_pwm_data = {
+	.enable_mask = BIT(16),
+	.con0 = 0xa8,
+	.con0_sel = 0x2,
+	.con1 = 0xac,
+	.has_commit = false,
+	.bls_debug = 0xb0,
+	.bls_debug_mask = 0x3,
+};
+
+static const struct mtk_pwm_data mt8173_pwm_data = {
+	.enable_mask = BIT(0),
+	.con0 = 0x10,
+	.con0_sel = 0x0,
+	.con1 = 0x14,
+	.has_commit = true,
+	.commit = 0x8,
+	.commit_mask = 0x1,
+};
+
 static const struct of_device_id mtk_disp_pwm_of_match[] = {
-	{ .compatible = "mediatek,mt8173-disp-pwm" },
-	{ .compatible = "mediatek,mt6595-disp-pwm" },
+	{ .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
+	{ .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
+	{ .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);

drivers/pwm/pwm-samsung.c

@@ -193,9 +193,18 @@ static unsigned long pwm_samsung_calc_tin(struct samsung_pwm_chip *chip,
 	 * divider settings and choose the lowest divisor that can generate
 	 * frequencies lower than requested.
 	 */
-	for (div = variant->div_base; div < 4; ++div)
-		if ((rate >> (variant->bits + div)) < freq)
-			break;
+	if (variant->bits < 32) {
+		/* Only for s3c24xx */
+		for (div = variant->div_base; div < 4; ++div)
+			if ((rate >> (variant->bits + div)) < freq)
+				break;
+	} else {
+		/*
+		 * Other variants have enough counter bits to generate any
+		 * requested rate, so no need to check higher divisors.
+		 */
+		div = variant->div_base;
+	}
 
 	pwm_samsung_set_divisor(chip, chan, BIT(div));
 

drivers/pwm/pwm-sun4i.c

@@ -284,6 +284,12 @@ static const struct sun4i_pwm_data sun4i_pwm_data_a20 = {
 	.npwm = 2,
 };
 
+static const struct sun4i_pwm_data sun4i_pwm_data_h3 = {
+	.has_prescaler_bypass = true,
+	.has_rdy = true,
+	.npwm = 1,
+};
+
 static const struct of_device_id sun4i_pwm_dt_ids[] = {
 	{
 		.compatible = "allwinner,sun4i-a10-pwm",
@@ -297,6 +303,9 @@ static const struct of_device_id sun4i_pwm_dt_ids[] = {
 	}, {
 		.compatible = "allwinner,sun7i-a20-pwm",
 		.data = &sun4i_pwm_data_a20,
+	}, {
+		.compatible = "allwinner,sun8i-h3-pwm",
+		.data = &sun4i_pwm_data_h3,
 	}, {
 		/* sentinel */
 	},

drivers/pwm/pwm-tipwmss.c

@@ -34,7 +34,6 @@ static int pwmss_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
 
 	/* Populate all the child nodes here... */
 	ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
@@ -46,31 +45,13 @@ static int pwmss_probe(struct platform_device *pdev)
 
 static int pwmss_remove(struct platform_device *pdev)
 {
-	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int pwmss_suspend(struct device *dev)
-{
-	pm_runtime_put_sync(dev);
-	return 0;
-}
-
-static int pwmss_resume(struct device *dev)
-{
-	pm_runtime_get_sync(dev);
-	return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
-
 static struct platform_driver pwmss_driver = {
 	.driver	= {
 		.name	= "pwmss",
-		.pm	= &pwmss_pm_ops,
 		.of_match_table	= pwmss_of_match,
 	},
 	.probe	= pwmss_probe,

drivers/pwm/pwm-twl.c

@@ -269,6 +269,22 @@ static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 		goto out;
 	}
 
+	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+		goto out;
+	}
+
+	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+		goto out;
+	}
+
 	twl->twl6030_toggle3 = val;
 out:
 	mutex_unlock(&twl->mutex);

drivers/pwm/sysfs.c

@@ -409,6 +409,24 @@ void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 	}
 }
 
+void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
+{
+	struct device *parent;
+	unsigned int i;
+
+	parent = class_find_device(&pwm_class, NULL, chip,
+				   pwmchip_sysfs_match);
+	if (!parent)
+		return;
+
+	for (i = 0; i < chip->npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+
+		if (test_bit(PWMF_EXPORTED, &pwm->flags))
+			pwm_unexport_child(parent, pwm);
+	}
+}
+
 static int __init pwm_sysfs_init(void)
 {
 	return class_register(&pwm_class);

include/linux/pwm.h

@@ -641,6 +641,7 @@ static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
 #ifdef CONFIG_PWM_SYSFS
 void pwmchip_sysfs_export(struct pwm_chip *chip);
 void pwmchip_sysfs_unexport(struct pwm_chip *chip);
+void pwmchip_sysfs_unexport_children(struct pwm_chip *chip);
 #else
 static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 {
@@ -649,6 +650,10 @@ static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 {
 }
+
+static inline void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
+{
+}
 #endif /* CONFIG_PWM_SYSFS */
 
 #endif /* __LINUX_PWM_H */