Merge tag 'pwm/for-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux

Pull pwm updates from Uwe Kleine-König:
 "Apart for the normal updates for dt bindings, cleanups and support for
  new device variants to existing drivers this completes the conversion
  to pwmchip_alloc() which was started in the v6.9 development cycle.

  Using pwmchip_alloc() is a precondition to the character device
  support which allows easier and faster access to PWM devices. However
  there are some issues I want to clean up before including it in
  mainline, so this isn't contained here despite it was in next for some
  time.

  Thanks to Alexandre Mergnat, Binbin Zhou, Dmitry Rokosov, George
  Stark, Jerome Brunet and Varshini Rajendran for their contributions.
  Further thanks go to AngeloGioacchino Del Regno, Conor Dooley, David
  Lechner, Fabrice Gasnier, Florian Fainelli, Guenter Roeck, Gustavo A.
  R. Silva, Krzysztof Kozlowski and Rob Herring for valuable patch
  review"

* tag 'pwm/for-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: (34 commits)
  pwm: pca9685: Drop explicit initialization of struct i2c_device_id::driver_data to 0
  dt-bindings: pwm: snps,dw-apb-timers: Do not require pwm-cells twice
  dt-bindings: pwm: mediatek,pwm-disp: Do not require pwm-cells twice
  dt-bindings: pwm: mediatek,mt2712: Do not require pwm-cells twice
  dt-bindings: pwm: marvell,pxa: Do not require pwm-cells twice
  dt-bindings: pwm: google,cros-ec: Do not require pwm-cells twice
  dt-bindings: pwm: bcm2835: Do not require pwm-cells twice
  pwm: meson: Use mul_u64_u64_div_u64() for frequency calculating
  pwm: meson: Add check for error from clk_round_rate()
  pwm: meson: Drop unneeded check in .get_state()
  dt-bindings: pwm: mediatek,pwm-disp: add compatible for mt8365 SoC
  pwm: meson: Add generic compatible for meson8 to sm1
  pwm: bcm2835: Drop open coded variant of devm_clk_rate_exclusive_get()
  pwm: bcm2835: Introduce a local variable for &pdev->dev
  pwm: stm32: Calculate prescaler with a division instead of a loop
  pwm: stm32: Fix for settings using period > UINT32_MAX
  pwm: stm32: Improve precision of calculation in .apply()
  pwm: stm32: Add error messages in .probe()'s error paths
  pwm: Make pwmchip_[sg]et_drvdata() a wrapper around dev_set_drvdata()
  pwm: Don't check pointer for being non-NULL after use
  ...

18 files changed, 830 insertions, 857 deletions

diff --git a/Documentation/devicetree/bindings/pwm/atmel,at91sam-pwm.yaml b/Documentation/devicetree/bindings/pwm/atmel,at91sam-pwm.yaml
index d84268b59784..96cd6f3c3546 100644
--- a/Documentation/devicetree/bindings/pwm/atmel,at91sam-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/atmel,at91sam-pwm.yaml
@@ -25,6 +25,9 @@ properties:
       - items:
           - const: microchip,sama7g5-pwm
           - const: atmel,sama5d2-pwm
+      - items:
+          - const: microchip,sam9x7-pwm
+          - const: microchip,sam9x60-pwm
 
   reg:
     maxItems: 1
diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
index 3afe1480df52..f7bc84b05a87 100644
--- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
@@ -35,7 +35,6 @@ properties:
 
 required:
   - compatible
-  - '#pwm-cells'
 
 additionalProperties: false
 
diff --git a/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml b/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
index ba6325575ea0..9ee1946dc2e1 100644
--- a/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/marvell,pxa-pwm.yaml
@@ -34,7 +34,6 @@ properties:
 required:
   - compatible
   - reg
-  - "#pwm-cells"
   - clocks
 
 additionalProperties: false
diff --git a/Documentation/devicetree/bindings/pwm/mediatek,mt2712-pwm.yaml b/Documentation/devicetree/bindings/pwm/mediatek,mt2712-pwm.yaml
index a5c308801619..d515c09e1021 100644
--- a/Documentation/devicetree/bindings/pwm/mediatek,mt2712-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/mediatek,mt2712-pwm.yaml
@@ -66,7 +66,6 @@ properties:
 required:
   - compatible
   - reg
-  - "#pwm-cells"
   - clocks
   - clock-names
 
diff --git a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
index bc813fe74fab..195e4371196b 100644
--- a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
+++ b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
@@ -31,6 +31,7 @@ properties:
               - mediatek,mt8188-disp-pwm
               - mediatek,mt8192-disp-pwm
               - mediatek,mt8195-disp-pwm
+              - mediatek,mt8365-disp-pwm
           - const: mediatek,mt8183-disp-pwm
 
   reg:
@@ -58,7 +59,6 @@ properties:
 required:
   - compatible
   - reg
-  - "#pwm-cells"
   - clocks
   - clock-names
 
diff --git a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.yaml b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.yaml
index 15e7fd98defc..9dc25f38fb94 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.yaml
@@ -29,7 +29,6 @@ required:
   - compatible
   - reg
   - clocks
-  - "#pwm-cells"
 
 additionalProperties: false
 
diff --git a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
index 4d0b5964443d..7523a89a1773 100644
--- a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
+++ b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
@@ -51,7 +51,6 @@ properties:
 required:
   - compatible
   - reg
-  - "#pwm-cells"
   - clocks
   - clock-names
 
diff --git a/drivers/hwmon/aspeed-g6-pwm-tach.c b/drivers/hwmon/aspeed-g6-pwm-tach.c
index 262d46fed3aa..08a2ded95e45 100644
--- a/drivers/hwmon/aspeed-g6-pwm-tach.c
+++ b/drivers/hwmon/aspeed-g6-pwm-tach.c
@@ -136,7 +136,6 @@ struct aspeed_pwm_tach_data {
 	struct clk *clk;
 	struct reset_control *reset;
 	unsigned long clk_rate;
-	struct pwm_chip chip;
 	bool tach_present[TACH_ASPEED_NR_TACHS];
 	u32 tach_divisor;
 };
@@ -144,7 +143,7 @@ struct aspeed_pwm_tach_data {
 static inline struct aspeed_pwm_tach_data *
 aspeed_pwm_chip_to_data(struct pwm_chip *chip)
 {
-	return container_of(chip, struct aspeed_pwm_tach_data, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int aspeed_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -195,7 +194,7 @@ static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	expect_period = div64_u64(ULLONG_MAX, (u64)priv->clk_rate);
 	expect_period = min(expect_period, state->period);
-	dev_dbg(chip->dev, "expect period: %lldns, duty_cycle: %lldns",
+	dev_dbg(pwmchip_parent(chip), "expect period: %lldns, duty_cycle: %lldns",
 		expect_period, state->duty_cycle);
 	/*
 	 * Pick the smallest value for div_h so that div_l can be the biggest
@@ -218,12 +217,12 @@ static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (div_l > 255)
 		div_l = 255;
 
-	dev_dbg(chip->dev, "clk source: %ld div_h %lld, div_l : %lld\n",
+	dev_dbg(pwmchip_parent(chip), "clk source: %ld div_h %lld, div_l : %lld\n",
 		priv->clk_rate, div_h, div_l);
 	/* duty_pt = duty_cycle * (PERIOD + 1) / period */
 	duty_pt = div64_u64(state->duty_cycle * priv->clk_rate,
 			    (u64)NSEC_PER_SEC * (div_l + 1) << div_h);
-	dev_dbg(chip->dev, "duty_cycle = %lld, duty_pt = %d\n",
+	dev_dbg(pwmchip_parent(chip), "duty_cycle = %lld, duty_pt = %d\n",
 		state->duty_cycle, duty_pt);
 
 	/*
@@ -459,6 +458,7 @@ static int aspeed_pwm_tach_probe(struct platform_device *pdev)
 	int ret;
 	struct device_node *child;
 	struct aspeed_pwm_tach_data *priv;
+	struct pwm_chip *chip;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -487,11 +487,14 @@ static int aspeed_pwm_tach_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	priv->chip.dev = dev;
-	priv->chip.ops = &aspeed_pwm_ops;
-	priv->chip.npwm = PWM_ASPEED_NR_PWMS;
+	chip = devm_pwmchip_alloc(dev, PWM_ASPEED_NR_PWMS, 0);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
 
-	ret = devm_pwmchip_add(dev, &priv->chip);
+	pwmchip_set_drvdata(chip, priv);
+	chip->ops = &aspeed_pwm_ops;
+
+	ret = devm_pwmchip_add(dev, chip);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
 
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 4b956d661755..1dd7921194f5 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -29,10 +29,6 @@ menuconfig PWM
 
 if PWM
 
-config PWM_SYSFS
-	bool
-	default y if SYSFS
-
 config PWM_DEBUG
 	bool "PWM lowlevel drivers additional checks and debug messages"
 	depends on DEBUG_KERNEL
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c5ec9e168ee7..90913519f11a 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_PWM)		+= core.o
-obj-$(CONFIG_PWM_SYSFS)		+= sysfs.o
 obj-$(CONFIG_PWM_AB8500)	+= pwm-ab8500.o
 obj-$(CONFIG_PWM_APPLE)		+= pwm-apple.o
 obj-$(CONFIG_PWM_ATMEL)		+= pwm-atmel.o
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 403525cc1783..18574857641e 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -343,9 +343,16 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
 	if (!try_module_get(chip->owner))
 		return -ENODEV;
 
+	if (!get_device(&chip->dev)) {
+		err = -ENODEV;
+		goto err_get_device;
+	}
+
 	if (ops->request) {
 		err = ops->request(chip, pwm);
 		if (err) {
+			put_device(&chip->dev);
+err_get_device:
 			module_put(chip->owner);
 			return err;
 		}
@@ -454,36 +461,557 @@ of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
 }
 EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
 
+struct pwm_export {
+	struct device pwm_dev;
+	struct pwm_device *pwm;
+	struct mutex lock;
+	struct pwm_state suspend;
+};
+
+static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)
+{
+	return container_of(pwmchip_dev, struct pwm_chip, dev);
+}
+
+static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
+{
+	return container_of(pwm_dev, struct pwm_export, pwm_dev);
+}
+
+static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+
+	return export->pwm;
+}
+
+static ssize_t period_show(struct device *pwm_dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+	struct pwm_state state;
+
+	pwm_get_state(pwm, &state);
+
+	return sysfs_emit(buf, "%llu\n", state.period);
+}
+
+static ssize_t period_store(struct device *pwm_dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t size)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+	struct pwm_device *pwm = export->pwm;
+	struct pwm_state state;
+	u64 val;
+	int ret;
+
+	ret = kstrtou64(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&export->lock);
+	pwm_get_state(pwm, &state);
+	state.period = val;
+	ret = pwm_apply_might_sleep(pwm, &state);
+	mutex_unlock(&export->lock);
+
+	return ret ? : size;
+}
+
+static ssize_t duty_cycle_show(struct device *pwm_dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+	struct pwm_state state;
+
+	pwm_get_state(pwm, &state);
+
+	return sysfs_emit(buf, "%llu\n", state.duty_cycle);
+}
+
+static ssize_t duty_cycle_store(struct device *pwm_dev,
+				struct device_attribute *attr,
+				const char *buf, size_t size)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+	struct pwm_device *pwm = export->pwm;
+	struct pwm_state state;
+	u64 val;
+	int ret;
+
+	ret = kstrtou64(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&export->lock);
+	pwm_get_state(pwm, &state);
+	state.duty_cycle = val;
+	ret = pwm_apply_might_sleep(pwm, &state);
+	mutex_unlock(&export->lock);
+
+	return ret ? : size;
+}
+
+static ssize_t enable_show(struct device *pwm_dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+	struct pwm_state state;
+
+	pwm_get_state(pwm, &state);
+
+	return sysfs_emit(buf, "%d\n", state.enabled);
+}
+
+static ssize_t enable_store(struct device *pwm_dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t size)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+	struct pwm_device *pwm = export->pwm;
+	struct pwm_state state;
+	int val, ret;
+
+	ret = kstrtoint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&export->lock);
+
+	pwm_get_state(pwm, &state);
+
+	switch (val) {
+	case 0:
+		state.enabled = false;
+		break;
+	case 1:
+		state.enabled = true;
+		break;
+	default:
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	ret = pwm_apply_might_sleep(pwm, &state);
+
+unlock:
+	mutex_unlock(&export->lock);
+	return ret ? : size;
+}
+
+static ssize_t polarity_show(struct device *pwm_dev,
+			     struct device_attribute *attr,
+			     char *buf)
+{
+	const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+	const char *polarity = "unknown";
+	struct pwm_state state;
+
+	pwm_get_state(pwm, &state);
+
+	switch (state.polarity) {
+	case PWM_POLARITY_NORMAL:
+		polarity = "normal";
+		break;
+
+	case PWM_POLARITY_INVERSED:
+		polarity = "inversed";
+		break;
+	}
+
+	return sysfs_emit(buf, "%s\n", polarity);
+}
+
+static ssize_t polarity_store(struct device *pwm_dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t size)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+	struct pwm_device *pwm = export->pwm;
+	enum pwm_polarity polarity;
+	struct pwm_state state;
+	int ret;
+
+	if (sysfs_streq(buf, "normal"))
+		polarity = PWM_POLARITY_NORMAL;
+	else if (sysfs_streq(buf, "inversed"))
+		polarity = PWM_POLARITY_INVERSED;
+	else
+		return -EINVAL;
+
+	mutex_lock(&export->lock);
+	pwm_get_state(pwm, &state);
+	state.polarity = polarity;
+	ret = pwm_apply_might_sleep(pwm, &state);
+	mutex_unlock(&export->lock);
+
+	return ret ? : size;
+}
+
+static ssize_t capture_show(struct device *pwm_dev,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+	struct pwm_capture result;
+	int ret;
+
+	ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle);
+}
+
+static DEVICE_ATTR_RW(period);
+static DEVICE_ATTR_RW(duty_cycle);
+static DEVICE_ATTR_RW(enable);
+static DEVICE_ATTR_RW(polarity);
+static DEVICE_ATTR_RO(capture);
+
+static struct attribute *pwm_attrs[] = {
+	&dev_attr_period.attr,
+	&dev_attr_duty_cycle.attr,
+	&dev_attr_enable.attr,
+	&dev_attr_polarity.attr,
+	&dev_attr_capture.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(pwm);
+
+static void pwm_export_release(struct device *pwm_dev)
+{
+	struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+
+	kfree(export);
+}
+
+static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
+{
+	struct pwm_export *export;
+	char *pwm_prop[2];
+	int ret;
+
+	if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
+		return -EBUSY;
+
+	export = kzalloc(sizeof(*export), GFP_KERNEL);
+	if (!export) {
+		clear_bit(PWMF_EXPORTED, &pwm->flags);
+		return -ENOMEM;
+	}
+
+	export->pwm = pwm;
+	mutex_init(&export->lock);
+
+	export->pwm_dev.release = pwm_export_release;
+	export->pwm_dev.parent = pwmchip_dev;
+	export->pwm_dev.devt = MKDEV(0, 0);
+	export->pwm_dev.groups = pwm_groups;
+	dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm);
+
+	ret = device_register(&export->pwm_dev);
+	if (ret) {
+		clear_bit(PWMF_EXPORTED, &pwm->flags);
+		put_device(&export->pwm_dev);
+		export = NULL;
+		return ret;
+	}
+	pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
+	pwm_prop[1] = NULL;
+	kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
+	kfree(pwm_prop[0]);
+
+	return 0;
+}
+
+static int pwm_unexport_match(struct device *pwm_dev, void *data)
+{
+	return pwm_from_dev(pwm_dev) == data;
+}
+
+static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm)
+{
+	struct device *pwm_dev;
+	char *pwm_prop[2];
+
+	if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
+		return -ENODEV;
+
+	pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
+	if (!pwm_dev)
+		return -ENODEV;
+
+	pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
+	pwm_prop[1] = NULL;
+	kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
+	kfree(pwm_prop[0]);
+
+	/* for device_find_child() */
+	put_device(pwm_dev);
+	device_unregister(pwm_dev);
+	pwm_put(pwm);
+
+	return 0;
+}
+
+static ssize_t export_store(struct device *pwmchip_dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t len)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+	struct pwm_device *pwm;
+	unsigned int hwpwm;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &hwpwm);
+	if (ret < 0)
+		return ret;
+
+	if (hwpwm >= chip->npwm)
+		return -ENODEV;
+
+	pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
+	if (IS_ERR(pwm))
+		return PTR_ERR(pwm);
+
+	ret = pwm_export_child(pwmchip_dev, pwm);
+	if (ret < 0)
+		pwm_put(pwm);
+
+	return ret ? : len;
+}
+static DEVICE_ATTR_WO(export);
+
+static ssize_t unexport_store(struct device *pwmchip_dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t len)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+	unsigned int hwpwm;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &hwpwm);
+	if (ret < 0)
+		return ret;
+
+	if (hwpwm >= chip->npwm)
+		return -ENODEV;
+
+	ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]);
+
+	return ret ? : len;
+}
+static DEVICE_ATTR_WO(unexport);
+
+static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr,
+			 char *buf)
+{
+	const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+
+	return sysfs_emit(buf, "%u\n", chip->npwm);
+}
+static DEVICE_ATTR_RO(npwm);
+
+static struct attribute *pwm_chip_attrs[] = {
+	&dev_attr_export.attr,
+	&dev_attr_unexport.attr,
+	&dev_attr_npwm.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pwm_chip);
+
+/* takes export->lock on success */
+static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev,
+					      struct pwm_device *pwm,
+					      struct pwm_state *state)
+{
+	struct device *pwm_dev;
+	struct pwm_export *export;
+
+	if (!test_bit(PWMF_EXPORTED, &pwm->flags))
+		return NULL;
+
+	pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
+	if (!pwm_dev)
+		return NULL;
+
+	export = pwmexport_from_dev(pwm_dev);
+	put_device(pwm_dev);	/* for device_find_child() */
+
+	mutex_lock(&export->lock);
+	pwm_get_state(pwm, state);
+
+	return export;
+}
+
+static int pwm_class_apply_state(struct pwm_export *export,
+				 struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	int ret = pwm_apply_might_sleep(pwm, state);
+
+	/* release lock taken in pwm_class_get_state */
+	mutex_unlock(&export->lock);
+
+	return ret;
+}
+
+static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+		struct pwm_state state;
+		struct pwm_export *export;
+
+		export = pwm_class_get_state(pwmchip_dev, pwm, &state);
+		if (!export)
+			continue;
+
+		/* If pwmchip was not enabled before suspend, do nothing. */
+		if (!export->suspend.enabled) {
+			/* release lock taken in pwm_class_get_state */
+			mutex_unlock(&export->lock);
+			continue;
+		}
+
+		state.enabled = export->suspend.enabled;
+		ret = pwm_class_apply_state(export, pwm, &state);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+static int pwm_class_suspend(struct device *pwmchip_dev)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < chip->npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+		struct pwm_state state;
+		struct pwm_export *export;
+
+		export = pwm_class_get_state(pwmchip_dev, pwm, &state);
+		if (!export)
+			continue;
+
+		/*
+		 * If pwmchip was not enabled before suspend, save
+		 * state for resume time and do nothing else.
+		 */
+		export->suspend = state;
+		if (!state.enabled) {
+			/* release lock taken in pwm_class_get_state */
+			mutex_unlock(&export->lock);
+			continue;
+		}
+
+		state.enabled = false;
+		ret = pwm_class_apply_state(export, pwm, &state);
+		if (ret < 0) {
+			/*
+			 * roll back the PWM devices that were disabled by
+			 * this suspend function.
+			 */
+			pwm_class_resume_npwm(pwmchip_dev, i);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int pwm_class_resume(struct device *pwmchip_dev)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+
+	return pwm_class_resume_npwm(pwmchip_dev, chip->npwm);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
+
+static struct class pwm_class = {
+	.name = "pwm",
+	.dev_groups = pwm_chip_groups,
+	.pm = pm_sleep_ptr(&pwm_class_pm_ops),
+};
+
+static void pwmchip_sysfs_unexport(struct pwm_chip *chip)
+{
+	unsigned int i;
+
+	for (i = 0; i < chip->npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+
+		if (test_bit(PWMF_EXPORTED, &pwm->flags))
+			pwm_unexport_child(&chip->dev, pwm);
+	}
+}
+
 #define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
 
 static void *pwmchip_priv(struct pwm_chip *chip)
 {
-	return (void *)chip + ALIGN(sizeof(*chip), PWMCHIP_ALIGN);
+	return (void *)chip + ALIGN(struct_size(chip, pwms, chip->npwm), PWMCHIP_ALIGN);
 }
 
 /* This is the counterpart to pwmchip_alloc() */
 void pwmchip_put(struct pwm_chip *chip)
 {
-	kfree(chip);
+	put_device(&chip->dev);
 }
 EXPORT_SYMBOL_GPL(pwmchip_put);
 
+static void pwmchip_release(struct device *pwmchip_dev)
+{
+	struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+
+	kfree(chip);
+}
+
 struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
 {
 	struct pwm_chip *chip;
+	struct device *pwmchip_dev;
 	size_t alloc_size;
+	unsigned int i;
 
-	alloc_size = size_add(ALIGN(sizeof(*chip), PWMCHIP_ALIGN), sizeof_priv);
+	alloc_size = size_add(ALIGN(struct_size(chip, pwms, npwm), PWMCHIP_ALIGN),
+			      sizeof_priv);
 
 	chip = kzalloc(alloc_size, GFP_KERNEL);
 	if (!chip)
 		return ERR_PTR(-ENOMEM);
 
-	chip->dev = parent;
 	chip->npwm = npwm;
+	chip->uses_pwmchip_alloc = true;
+
+	pwmchip_dev = &chip->dev;
+	device_initialize(pwmchip_dev);
+	pwmchip_dev->class = &pwm_class;
+	pwmchip_dev->parent = parent;
+	pwmchip_dev->release = pwmchip_release;
 
 	pwmchip_set_drvdata(chip, pwmchip_priv(chip));
 
+	for (i = 0; i < chip->npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+		pwm->chip = chip;
+		pwm->hwpwm = i;
+	}
+
 	return chip;
 }
 EXPORT_SYMBOL_GPL(pwmchip_alloc);
@@ -555,47 +1083,56 @@ static bool pwm_ops_check(const struct pwm_chip *chip)
  */
 int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
 {
-	unsigned int i;
 	int ret;
 
 	if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm)
 		return -EINVAL;
 
+	/*
+	 * a struct pwm_chip must be allocated using (devm_)pwmchip_alloc,
+	 * otherwise the embedded struct device might disappear too early
+	 * resulting in memory corruption.
+	 * Catch drivers that were not converted appropriately.
+	 */
+	if (!chip->uses_pwmchip_alloc)
+		return -EINVAL;
+
 	if (!pwm_ops_check(chip))
 		return -EINVAL;
 
 	chip->owner = owner;
 
-	chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL);
-	if (!chip->pwms)
-		return -ENOMEM;
-
 	mutex_lock(&pwm_lock);
 
 	ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);
-	if (ret < 0) {
-		mutex_unlock(&pwm_lock);
-		kfree(chip->pwms);
-		return ret;
-	}
+	if (ret < 0)
+		goto err_idr_alloc;
 
 	chip->id = ret;
 
-	for (i = 0; i < chip->npwm; i++) {
-		struct pwm_device *pwm = &chip->pwms[i];
+	dev_set_name(&chip->dev, "pwmchip%u", chip->id);
 
-		pwm->chip = chip;
-		pwm->hwpwm = i;
-	}
+	if (IS_ENABLED(CONFIG_OF))
+		of_pwmchip_add(chip);
+
+	ret = device_add(&chip->dev);
+	if (ret)
+		goto err_device_add;
 
 	mutex_unlock(&pwm_lock);
 
+	return 0;
+
+err_device_add:
 	if (IS_ENABLED(CONFIG_OF))
-		of_pwmchip_add(chip);
+		of_pwmchip_remove(chip);
 
-	pwmchip_sysfs_export(chip);
+	idr_remove(&pwm_chips, chip->id);
+err_idr_alloc:
 
-	return 0;
+	mutex_unlock(&pwm_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__pwmchip_add);
 
@@ -618,7 +1155,7 @@ void pwmchip_remove(struct pwm_chip *chip)
 
 	mutex_unlock(&pwm_lock);
 
-	kfree(chip->pwms);
+	device_del(&chip->dev);
 }
 EXPORT_SYMBOL_GPL(pwmchip_remove);
 
@@ -988,9 +1525,13 @@ EXPORT_SYMBOL_GPL(pwm_get);
  */
 void pwm_put(struct pwm_device *pwm)
 {
+	struct pwm_chip *chip;
+
 	if (!pwm)
 		return;
 
+	chip = pwm->chip;
+
 	mutex_lock(&pwm_lock);
 
 	if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
@@ -998,12 +1539,14 @@ void pwm_put(struct pwm_device *pwm)
 		goto out;
 	}
 
-	if (pwm->chip->ops->free)
+	if (chip->ops->free)
 		pwm->chip->ops->free(pwm->chip, pwm);
 
 	pwm->label = NULL;
 
-	module_put(pwm->chip->owner);
+	put_device(&chip->dev);
+
+	module_put(chip->owner);
 out:
 	mutex_unlock(&pwm_lock);
 }
@@ -1076,7 +1619,6 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
 
-#ifdef CONFIG_DEBUG_FS
 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 {
 	unsigned int i;
@@ -1161,11 +1703,11 @@ static const struct seq_operations pwm_debugfs_sops = {
 
 DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
 
-static int __init pwm_debugfs_init(void)
+static int __init pwm_init(void)
 {
-	debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
 
-	return 0;
+	return class_register(&pwm_class);
 }
-subsys_initcall(pwm_debugfs_init);
-#endif /* CONFIG_DEBUG_FS */
+subsys_initcall(pwm_init);
diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index aa35acbb0cbc..578e95e0296c 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -124,20 +124,14 @@ static const struct pwm_ops bcm2835_pwm_ops = {
 	.apply = bcm2835_pwm_apply,
 };
 
-static void devm_clk_rate_exclusive_put(void *data)
-{
-	struct clk *clk = data;
-
-	clk_rate_exclusive_put(clk);
-}
-
 static int bcm2835_pwm_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct pwm_chip *chip;
 	struct bcm2835_pwm *pc;
 	int ret;
 
-	chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*pc));
+	chip = devm_pwmchip_alloc(dev, 2, sizeof(*pc));