1 files changed, 517 insertions, 111 deletions

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 70cc0d134f3c..37269db2de84 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -1,63 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  *
  * Author: Kamil Debski <k.debski@samsung.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
+#include <linux/delay.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
-#include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/pwm.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>
+#include <linux/timer.h>
 
 #define MAX_PWM 255
 
+struct pwm_fan_tach {
+	int irq;
+	atomic_t pulses;
+	unsigned int rpm;
+};
+
+enum pwm_fan_enable_mode {
+	pwm_off_reg_off,
+	pwm_disable_reg_enable,
+	pwm_enable_reg_enable,
+	pwm_disable_reg_disable,
+};
+
 struct pwm_fan_ctx {
+	struct device *dev;
+
 	struct mutex lock;
 	struct pwm_device *pwm;
+	struct pwm_state pwm_state;
+	struct regulator *reg_en;
+	enum pwm_fan_enable_mode enable_mode;
+	bool regulator_enabled;
+	bool enabled;
+
+	int tach_count;
+	struct pwm_fan_tach *tachs;
+	u32 *pulses_per_revolution;
+	ktime_t sample_start;
+	struct timer_list rpm_timer;
+
 	unsigned int pwm_value;
 	unsigned int pwm_fan_state;
 	unsigned int pwm_fan_max_state;
 	unsigned int *pwm_fan_cooling_levels;
 	struct thermal_cooling_device *cdev;
+
+	struct hwmon_chip_info info;
+	struct hwmon_channel_info fan_channel;
+
+	u64 pwm_duty_cycle_from_stopped;
+	u32 pwm_usec_from_stopped;
+	u8 pwm_shutdown;
 };
 
-static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
+/* This handler assumes self resetting edge triggered interrupt. */
+static irqreturn_t pulse_handler(int irq, void *dev_id)
+{
+	struct pwm_fan_tach *tach = dev_id;
+
+	atomic_inc(&tach->pulses);
+
+	return IRQ_HANDLED;
+}
+
+static void sample_timer(struct timer_list *t)
+{
+	struct pwm_fan_ctx *ctx = timer_container_of(ctx, t, rpm_timer);
+	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
+	int i;
+
+	if (delta) {
+		for (i = 0; i < ctx->tach_count; i++) {
+			struct pwm_fan_tach *tach = &ctx->tachs[i];
+			int pulses;
+
+			pulses = atomic_read(&tach->pulses);
+			atomic_sub(pulses, &tach->pulses);
+			tach->rpm = (unsigned int)(pulses * 1000 * 60) /
+				(ctx->pulses_per_revolution[i] * delta);
+		}
+
+		ctx->sample_start = ktime_get();
+	}
+
+	mod_timer(&ctx->rpm_timer, jiffies + HZ);
+}
+
+static void pwm_fan_enable_mode_2_state(int enable_mode,
+					struct pwm_state *state,
+					bool *enable_regulator)
+{
+	switch (enable_mode) {
+	case pwm_disable_reg_enable:
+		/* disable pwm, keep regulator enabled */
+		state->enabled = false;
+		*enable_regulator = true;
+		break;
+	case pwm_enable_reg_enable:
+		/* keep pwm and regulator enabled */
+		state->enabled = true;
+		*enable_regulator = true;
+		break;
+	case pwm_off_reg_off:
+	case pwm_disable_reg_disable:
+		/* disable pwm and regulator */
+		state->enabled = false;
+		*enable_regulator = false;
+	}
+}
+
+static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
 {
-	unsigned long period;
 	int ret = 0;
-	struct pwm_state state = { };
 
-	mutex_lock(&ctx->lock);
-	if (ctx->pwm_value == pwm)
-		goto exit_set_pwm_err;
+	if (!ctx->reg_en)
+		return ret;
+
+	if (!ctx->regulator_enabled && on) {
+		ret = regulator_enable(ctx->reg_en);
+		if (ret == 0)
+			ctx->regulator_enabled = true;
+	} else if (ctx->regulator_enabled && !on) {
+		ret = regulator_disable(ctx->reg_en);
+		if (ret == 0)
+			ctx->regulator_enabled = false;
+	}
+	return ret;
+}
+
+static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
+{
+	struct pwm_state *state = &ctx->pwm_state;
+	int ret;
 
-	pwm_init_state(ctx->pwm, &state);
-	period = ctx->pwm->args.period;
-	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
-	state.enabled = pwm ? true : false;
+	if (ctx->enabled)
+		return 0;
+
+	ret = pwm_fan_switch_power(ctx, true);
+	if (ret < 0) {
+		dev_err(ctx->dev, "failed to enable power supply\n");
+		return ret;
+	}
+
+	state->enabled = true;
+	ret = pwm_apply_might_sleep(ctx->pwm, state);
+	if (ret) {
+		dev_err(ctx->dev, "failed to enable PWM\n");
+		goto disable_regulator;
+	}
+
+	ctx->enabled = true;
+
+	return 0;
+
+disable_regulator:
+	pwm_fan_switch_power(ctx, false);
+	return ret;
+}
+
+static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable)
+{
+	struct pwm_state *state = &ctx->pwm_state;
+	bool enable_regulator = false;
+	int ret;
+
+	if (!ctx->enabled)
+		return 0;
+
+	pwm_fan_enable_mode_2_state(ctx->enable_mode,
+				    state,
+				    &enable_regulator);
+
+	if (force_disable)
+		state->enabled = false;
+	state->duty_cycle = 0;
+	ret = pwm_apply_might_sleep(ctx->pwm, state);
+	if (ret) {
+		dev_err(ctx->dev, "failed to disable PWM\n");
+		return ret;
+	}
+
+	pwm_fan_switch_power(ctx, enable_regulator);
+
+	ctx->enabled = false;
+
+	return 0;
+}
+
+static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
+{
+	struct pwm_state *state = &ctx->pwm_state;
+	unsigned long final_pwm = pwm;
+	unsigned long period;
+	bool update = false;
+	int ret = 0;
 
-	ret = pwm_apply_state(ctx->pwm, &state);
+	if (pwm > 0) {
+		if (ctx->enable_mode == pwm_off_reg_off)
+			/* pwm-fan hard disabled */
+			return 0;
+
+		period = state->period;
+		update = state->duty_cycle < ctx->pwm_duty_cycle_from_stopped;
+		if (update)
+			state->duty_cycle = ctx->pwm_duty_cycle_from_stopped;
+		else
+			state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
+		ret = pwm_apply_might_sleep(ctx->pwm, state);
+		if (ret)
+			return ret;
+		ret = pwm_fan_power_on(ctx);
+		if (!ret && update) {
+			pwm = final_pwm;
+			state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
+			usleep_range(ctx->pwm_usec_from_stopped,
+				     ctx->pwm_usec_from_stopped * 2);
+			ret = pwm_apply_might_sleep(ctx->pwm, state);
+		}
+	} else {
+		ret = pwm_fan_power_off(ctx, false);
+	}
 	if (!ret)
 		ctx->pwm_value = pwm;
-exit_set_pwm_err:
+
+	return ret;
+}
+
+static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
+{
+	int ret;
+
+	mutex_lock(&ctx->lock);
+	ret = __set_pwm(ctx, pwm);
 	mutex_unlock(&ctx->lock);
+
 	return ret;
 }
 
@@ -72,41 +262,128 @@ static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
 	ctx->pwm_fan_state = i;
 }
 
-static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
-		       const char *buf, size_t count)
+static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val)
+{
+	int ret = 0;
+	int old_val;
+
+	mutex_lock(&ctx->lock);
+
+	if (ctx->enable_mode == val)
+		goto out;
+
+	old_val = ctx->enable_mode;
+	ctx->enable_mode = val;
+
+	if (val == 0) {
+		/* Disable pwm-fan unconditionally */
+		if (ctx->enabled)
+			ret = __set_pwm(ctx, 0);
+		else
+			ret = pwm_fan_switch_power(ctx, false);
+		if (ret)
+			ctx->enable_mode = old_val;
+		pwm_fan_update_state(ctx, 0);
+	} else {
+		/*
+		 * Change PWM and/or regulator state if currently disabled
+		 * Nothing to do if currently enabled
+		 */
+		if (!ctx->enabled) {
+			struct pwm_state *state = &ctx->pwm_state;
+			bool enable_regulator = false;
+
+			state->duty_cycle = 0;
+			pwm_fan_enable_mode_2_state(val,
+						    state,
+						    &enable_regulator);
+
+			pwm_apply_might_sleep(ctx->pwm, state);
+			pwm_fan_switch_power(ctx, enable_regulator);
+			pwm_fan_update_state(ctx, 0);
+		}
+	}
+out:
+	mutex_unlock(&ctx->lock);
+
+	return ret;
+}
+
+static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
-	unsigned long pwm;
 	int ret;
 
-	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
-		return -EINVAL;
+	switch (attr) {
+	case hwmon_pwm_input:
+		if (val < 0 || val > MAX_PWM)
+			return -EINVAL;
+		ret = set_pwm(ctx, val);
+		if (ret)
+			return ret;
+		pwm_fan_update_state(ctx, val);
+		break;
+	case hwmon_pwm_enable:
+		if (val < 0 || val > 3)
+			ret = -EINVAL;
+		else
+			ret = pwm_fan_update_enable(ctx, val);
 
-	ret = __set_pwm(ctx, pwm);
-	if (ret)
 		return ret;
+	default:
+		return -EOPNOTSUPP;
+	}
 
-	pwm_fan_update_state(ctx, pwm);
-	return count;
+	return 0;
 }
 
-static ssize_t show_pwm(struct device *dev,
-			struct device_attribute *attr, char *buf)
+static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%u\n", ctx->pwm_value);
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			*val = ctx->pwm_value;
+			return 0;
+		case hwmon_pwm_enable:
+			*val = ctx->enable_mode;
+			return 0;
+		}
+		return -EOPNOTSUPP;
+	case hwmon_fan:
+		*val = ctx->tachs[channel].rpm;
+		return 0;
+
+	default:
+		return -ENOTSUPP;
+	}
 }
 
+static umode_t pwm_fan_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_pwm:
+		return 0644;
 
-static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0);
+	case hwmon_fan:
+		return 0444;
 
-static struct attribute *pwm_fan_attrs[] = {
-	&sensor_dev_attr_pwm1.dev_attr.attr,
-	NULL,
-};
+	default:
+		return 0;
+	}
+}
 
-ATTRIBUTE_GROUPS(pwm_fan);
+static const struct hwmon_ops pwm_fan_hwmon_ops = {
+	.is_visible = pwm_fan_is_visible,
+	.read = pwm_fan_read,
+	.write = pwm_fan_write,
+};
 
 /* thermal cooling device callbacks */
 static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
@@ -147,7 +424,7 @@ pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
 	if (state == ctx->pwm_fan_state)
 		return 0;
 
-	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
+	ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
 	if (ret) {
 		dev_err(&cdev->device, "Cannot set pwm!\n");
 		return ret;
@@ -164,29 +441,27 @@ static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
 	.set_cur_state = pwm_fan_set_cur_state,
 };
 
-static int pwm_fan_of_get_cooling_data(struct device *dev,
-				       struct pwm_fan_ctx *ctx)
+static int pwm_fan_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
 {
-	struct device_node *np = dev->of_node;
 	int num, i, ret;
 
-	if (!of_find_property(np, "cooling-levels", NULL))
+	if (!device_property_present(dev, "cooling-levels"))
 		return 0;
 
-	ret = of_property_count_u32_elems(np, "cooling-levels");
+	ret = device_property_count_u32(dev, "cooling-levels");
 	if (ret <= 0) {
 		dev_err(dev, "Wrong data!\n");
 		return ret ? : -EINVAL;
 	}
 
 	num = ret;
-	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
+	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
 						   GFP_KERNEL);
 	if (!ctx->pwm_fan_cooling_levels)
 		return -ENOMEM;
 
-	ret = of_property_read_u32_array(np, "cooling-levels",
-					 ctx->pwm_fan_cooling_levels, num);
+	ret = device_property_read_u32_array(dev, "cooling-levels",
+					     ctx->pwm_fan_cooling_levels, num);
 	if (ret) {
 		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
 		return ret;
@@ -205,117 +480,248 @@ static int pwm_fan_of_get_cooling_data(struct device *dev,
 	return 0;
 }
 
+static void pwm_fan_cleanup(void *__ctx)
+{
+	struct pwm_fan_ctx *ctx = __ctx;
+
+	timer_delete_sync(&ctx->rpm_timer);
+	if (ctx->pwm_shutdown) {
+		ctx->enable_mode = pwm_enable_reg_enable;
+		__set_pwm(ctx, ctx->pwm_shutdown);
+	} else {
+		/* Switch off everything */
+		ctx->enable_mode = pwm_disable_reg_disable;
+		pwm_fan_power_off(ctx, true);
+	}
+}
+
 static int pwm_fan_probe(struct platform_device *pdev)
 {
 	struct thermal_cooling_device *cdev;
+	struct device *dev = &pdev->dev;
 	struct pwm_fan_ctx *ctx;
 	struct device *hwmon;
 	int ret;
-	struct pwm_state state = { };
+	const struct hwmon_channel_info **channels;
+	u32 initial_pwm, pwm_min_from_stopped = 0;
+	u32 pwm_shutdown_percent = 0;
+	u32 *fan_channel_config;
+	int channel_count = 1;	/* We always have a PWM channel. */
+	int i;
 
-	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
 
 	mutex_init(&ctx->lock);
 
-	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
-	if (IS_ERR(ctx->pwm)) {
-		dev_err(&pdev->dev, "Could not get PWM\n");
-		return PTR_ERR(ctx->pwm);
-	}
+	ctx->dev = &pdev->dev;
+	ctx->pwm = devm_pwm_get(dev, NULL);
+	if (IS_ERR(ctx->pwm))
+		return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
 
 	platform_set_drvdata(pdev, ctx);
 
-	ctx->pwm_value = MAX_PWM;
+	ctx->reg_en = devm_regulator_get_optional(dev, "fan");
+	if (IS_ERR(ctx->reg_en)) {
+		if (PTR_ERR(ctx->reg_en) != -ENODEV)
+			return PTR_ERR(ctx->reg_en);
 
-	/* Set duty cycle to maximum allowed and enable PWM output */
-	pwm_init_state(ctx->pwm, &state);
-	state.duty_cycle = ctx->pwm->args.period - 1;
-	state.enabled = true;
+		ctx->reg_en = NULL;
+	}
 
-	ret = pwm_apply_state(ctx->pwm, &state);
+	pwm_init_state(ctx->pwm, &ctx->pwm_state);
+
+	/*
+	 * PWM fans are controlled solely by the duty cycle of the PWM signal,
+	 * they do not care about the exact timing. Thus set usage_power to true
+	 * to allow less flexible hardware to work as a PWM source for fan
+	 * control.
+	 */
+	ctx->pwm_state.usage_power = true;
+
+	/*
+	 * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
+	 * long. Check this here to prevent the fan running at a too low
+	 * frequency.
+	 */
+	if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
+		dev_err(dev, "Configured period too big\n");
+		return -EINVAL;
+	}
+
+	ctx->enable_mode = pwm_disable_reg_enable;
+
+	ret = pwm_fan_get_cooling_data(dev, ctx);
+	if (ret)
+		return ret;
+
+	/* use maximum cooling level if provided */
+	if (ctx->pwm_fan_cooling_levels)
+		initial_pwm = ctx->pwm_fan_cooling_levels[ctx->pwm_fan_max_state];
+	else
+		initial_pwm = MAX_PWM;
+
+	/*
+	 * Set duty cycle to maximum allowed and enable PWM output as well as
+	 * the regulator. In case of error nothing is changed
+	 */
+	ret = set_pwm(ctx, initial_pwm);
 	if (ret) {
-		dev_err(&pdev->dev, "Failed to configure PWM\n");
+		dev_err(dev, "Failed to configure PWM: %d\n", ret);
 		return ret;
 	}
+	timer_setup(&ctx->rpm_timer, sample_timer, 0);
+	ret = devm_add_action_or_reset(dev, pwm_fan_cleanup, ctx);
+	if (ret)
+		return ret;
 
-	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
-						       ctx, pwm_fan_groups);
-	if (IS_ERR(hwmon)) {
-		dev_err(&pdev->dev, "Failed to register hwmon device\n");
-		ret = PTR_ERR(hwmon);
-		goto err_pwm_disable;
+	ctx->tach_count = platform_irq_count(pdev);
+	if (ctx->tach_count < 0)
+		return dev_err_probe(dev, ctx->tach_count,
+				     "Could not get number of fan tachometer inputs\n");
+	dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
+
+	if (ctx->tach_count) {
+		channel_count++;	/* We also have a FAN channel. */
+
+		ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
+					  sizeof(struct pwm_fan_tach),
+					  GFP_KERNEL);
+		if (!ctx->tachs)
+			return -ENOMEM;
+
+		ctx->fan_channel.type = hwmon_fan;
+		fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
+						  sizeof(u32), GFP_KERNEL);
+		if (!fan_channel_config)
+			return -ENOMEM;
+		ctx->fan_channel.config = fan_channel_config;
+
+		ctx->pulses_per_revolution = devm_kmalloc_array(dev,
+								ctx->tach_count,
+								sizeof(*ctx->pulses_per_revolution),
+								GFP_KERNEL);
+		if (!ctx->pulses_per_revolution)
+			return -ENOMEM;
+
+		/* Setup default pulses per revolution */
+		for (i = 0; i < ctx->tach_count; i++)
+			ctx->pulses_per_revolution[i] = 2;
+
+		device_property_read_u32_array(dev, "pulses-per-revolution",
+					       ctx->pulses_per_revolution, ctx->tach_count);
+	}
+
+	channels = devm_kcalloc(dev, channel_count + 1,
+				sizeof(struct hwmon_channel_info *), GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE);
+
+	for (i = 0; i < ctx->tach_count; i++) {
+		struct pwm_fan_tach *tach = &ctx->tachs[i];
+
+		tach->irq = platform_get_irq(pdev, i);
+		if (tach->irq == -EPROBE_DEFER)
+			return tach->irq;
+		if (tach->irq > 0) {
+			ret = devm_request_irq(dev, tach->irq, pulse_handler,
+					       IRQF_NO_THREAD, pdev->name, tach);
+			if (ret) {
+				dev_err(dev,
+					"Failed to request interrupt: %d\n",
+					ret);
+				return ret;
+			}
+		}
+
+		if (!ctx->pulses_per_revolution[i]) {
+			dev_err(dev, "pulses-per-revolution can't be zero.\n");
+			return -EINVAL;
+		}
+
+		fan_channel_config[i] = HWMON_F_INPUT;
+
+		dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
+			i, tach->irq, ctx->pulses_per_revolution[i]);
 	}
 
-	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
+	if (ctx->tach_count > 0) {
+		ctx->sample_start = ktime_get();
+		mod_timer(&ctx->rpm_timer, jiffies + HZ);
+
+		channels[1] = &ctx->fan_channel;
+	}
+
+	ret = device_property_read_u32(dev, "fan-shutdown-percent",
+				       &pwm_shutdown_percent);
+	if (!ret && pwm_shutdown_percent)
+		ctx->pwm_shutdown = (clamp(pwm_shutdown_percent, 0, 100) * 255) / 100;
+
+	ret = device_property_read_u32(dev, "fan-stop-to-start-percent",
+				       &pwm_min_from_stopped);
+	if (!ret && pwm_min_from_stopped) {
+		ctx->pwm_duty_cycle_from_stopped =
+			DIV_ROUND_UP_ULL(pwm_min_from_stopped *
+					 (ctx->pwm_state.period - 1),
+					 100);
+	}
+	ret = device_property_read_u32(dev, "fan-stop-to-start-us",
+				       &ctx->pwm_usec_from_stopped);
 	if (ret)
-		return ret;
+		ctx->pwm_usec_from_stopped = 250000;
+
+	ctx->info.ops = &pwm_fan_hwmon_ops;
+	ctx->info.info = channels;
+
+	hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
+						     ctx, &ctx->info, NULL);
+	if (IS_ERR(hwmon)) {
+		dev_err(dev, "Failed to register hwmon device\n");
+		return PTR_ERR(hwmon);
+	}
 
 	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
 	if (IS_ENABLED(CONFIG_THERMAL)) {
-		cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
-							  "pwm-fan", ctx,
-							  &pwm_fan_cooling_ops);
+		cdev = devm_thermal_of_cooling_device_register(dev,
+			dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
 		if (IS_ERR(cdev)) {
-			dev_err(&pdev->dev,
-				"Failed to register pwm-fan as cooling device");
 			ret = PTR_ERR(cdev);
-			goto err_pwm_disable;
+			dev_err(dev,
+				"Failed to register pwm-fan as cooling device: %d\n",
+				ret);
+			return ret;
 		}
 		ctx->cdev = cdev;
-		thermal_cdev_update(cdev);
 	}
 
 	return 0;
-
-err_pwm_disable:
-	state.enabled = false;
-	pwm_apply_state(ctx->pwm, &state);
-
-	return ret;
 }
 
-static int pwm_fan_remove(struct platform_device *pdev)
+static void pwm_fan_shutdown(struct platform_device *pdev)
 {
 	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
 
-	thermal_cooling_device_unregister(ctx->cdev);
-	if (ctx->pwm_value)
-		pwm_disable(ctx->pwm);
-	return 0;
+	pwm_fan_cleanup(ctx);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int pwm_fan_suspend(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
-	if (ctx->pwm_value)
-		pwm_disable(ctx->pwm);
-	return 0;
+	return pwm_fan_power_off(ctx, true);
 }
 
 static int pwm_fan_resume(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
-	struct pwm_args pargs;
-	unsigned long duty;
-	int ret;
 
-	if (ctx->pwm_value == 0)
-		return 0;
-
-	pwm_get_args(ctx->pwm, &pargs);
-	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, pargs.period);
-	if (ret)
-		return ret;
-	return pwm_enable(ctx->pwm);
+	return set_pwm(ctx, ctx->pwm_value);
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
 
 static const struct of_device_id of_pwm_fan_match[] = {
 	{ .compatible = "pwm-fan", },
@@ -325,10 +731,10 @@ MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
 
 static struct platform_driver pwm_fan_driver = {
 	.probe		= pwm_fan_probe,
-	.remove		= pwm_fan_remove,
+	.shutdown	= pwm_fan_shutdown,
 	.driver	= {
 		.name		= "pwm-fan",
-		.pm		= &pwm_fan_pm,
+		.pm		= pm_sleep_ptr(&pwm_fan_pm),
 		.of_match_table	= of_pwm_fan_match,
 	},
 };