[linux-2.6-block.git] / drivers / hwmon / pwm-fan.c

// 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>
 */

#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.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_ctx {
	struct mutex lock;
	struct pwm_device *pwm;
	struct regulator *reg_en;

	int irq;
	atomic_t pulses;
	unsigned int rpm;
	u8 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;
};

/* This handler assumes self resetting edge triggered interrupt. */
static irqreturn_t pulse_handler(int irq, void *dev_id)
{
	struct pwm_fan_ctx *ctx = dev_id;

	atomic_inc(&ctx->pulses);

	return IRQ_HANDLED;
}

static void sample_timer(struct timer_list *t)
{
	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
	int pulses;
	u64 tmp;

	pulses = atomic_read(&ctx->pulses);
	atomic_sub(pulses, &ctx->pulses);
	tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60;
	do_div(tmp, ctx->pulses_per_revolution * 1000);
	ctx->rpm = tmp;

	ctx->sample_start = ktime_get();
	mod_timer(&ctx->rpm_timer, jiffies + HZ);
}

static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
	unsigned long period;
	int ret = 0;
	struct pwm_state state = { };

	mutex_lock(&ctx->lock);
	if (ctx->pwm_value == pwm)
		goto exit_set_pwm_err;

	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;

	ret = pwm_apply_state(ctx->pwm, &state);
	if (!ret)
		ctx->pwm_value = pwm;
exit_set_pwm_err:
	mutex_unlock(&ctx->lock);
	return ret;
}

static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
	int i;

	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
		if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
			break;

	ctx->pwm_fan_state = i;
}

static ssize_t pwm_store(struct device *dev, struct device_attribute *attr,
			 const char *buf, size_t count)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	unsigned long pwm;
	int ret;

	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
		return -EINVAL;

	ret = __set_pwm(ctx, pwm);
	if (ret)
		return ret;

	pwm_fan_update_state(ctx, pwm);
	return count;
}

static ssize_t pwm_show(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", ctx->pwm_value);
}

static ssize_t rpm_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", ctx->rpm);
}

static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0);

static struct attribute *pwm_fan_attrs[] = {
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	NULL,
};

static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a,
				     int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);

	/* Hide fan_input in case no interrupt is available  */
	if (n == 1 && ctx->irq <= 0)
		return 0;

	return a->mode;
}

static const struct attribute_group pwm_fan_group = {
	.attrs = pwm_fan_attrs,
	.is_visible = pwm_fan_attrs_visible,
};

static const struct attribute_group *pwm_fan_groups[] = {
	&pwm_fan_group,
	NULL,
};

/* thermal cooling device callbacks */
static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	struct pwm_fan_ctx *ctx = cdev->devdata;

	if (!ctx)
		return -EINVAL;

	*state = ctx->pwm_fan_max_state;

	return 0;
}

static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	struct pwm_fan_ctx *ctx = cdev->devdata;

	if (!ctx)
		return -EINVAL;

	*state = ctx->pwm_fan_state;

	return 0;
}

static int
pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
{
	struct pwm_fan_ctx *ctx = cdev->devdata;
	int ret;

	if (!ctx || (state > ctx->pwm_fan_max_state))
		return -EINVAL;

	if (state == ctx->pwm_fan_state)
		return 0;

	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	if (ret) {
		dev_err(&cdev->device, "Cannot set pwm!\n");
		return ret;
	}

	ctx->pwm_fan_state = state;

	return ret;
}

static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	.get_max_state = pwm_fan_get_max_state,
	.get_cur_state = pwm_fan_get_cur_state,
	.set_cur_state = pwm_fan_set_cur_state,
};

static int pwm_fan_of_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))
		return 0;

	ret = of_property_count_u32_elems(np, "cooling-levels");
	if (ret <= 0) {
		dev_err(dev, "Wrong data!\n");
		return ret ? : -EINVAL;
	}

	num = ret;
	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);
	if (ret) {
		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
		return ret;
	}

	for (i = 0; i < num; i++) {
		if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
			dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
				ctx->pwm_fan_cooling_levels[i], MAX_PWM);
			return -EINVAL;
		}
	}

	ctx->pwm_fan_max_state = num - 1;

	return 0;
}

static void pwm_fan_regulator_disable(void *data)
{
	regulator_disable(data);
}

static void pwm_fan_pwm_disable(void *__ctx)
{
	struct pwm_fan_ctx *ctx = __ctx;
	pwm_disable(ctx->pwm);
	del_timer_sync(&ctx->rpm_timer);
}

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 = { };
	u32 ppr = 2;

	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	mutex_init(&ctx->lock);

	ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
	if (IS_ERR(ctx->pwm)) {
		ret = PTR_ERR(ctx->pwm);

		if (ret != -EPROBE_DEFER)
			dev_err(dev, "Could not get PWM: %d\n", ret);

		return ret;
	}

	platform_set_drvdata(pdev, ctx);

	ctx->irq = platform_get_irq(pdev, 0);
	if (ctx->irq == -EPROBE_DEFER)
		return ctx->irq;

	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);

		ctx->reg_en = NULL;
	} else {
		ret = regulator_enable(ctx->reg_en);
		if (ret) {
			dev_err(dev, "Failed to enable fan supply: %d\n", ret);
			return ret;
		}
		devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
					 ctx->reg_en);
	}

	ctx->pwm_value = MAX_PWM;

	/* 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;

	ret = pwm_apply_state(ctx->pwm, &state);
	if (ret) {
		dev_err(dev, "Failed to configure PWM: %d\n", ret);
		return ret;
	}
	timer_setup(&ctx->rpm_timer, sample_timer, 0);
	devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);

	of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);
	ctx->pulses_per_revolution = ppr;
	if (!ctx->pulses_per_revolution) {
		dev_err(dev, "pulses-per-revolution can't be zero.\n");
		return -EINVAL;
	}

	if (ctx->irq > 0) {
		ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
				       pdev->name, ctx);
		if (ret) {
			dev_err(dev, "Failed to request interrupt: %d\n", ret);
			return ret;
		}
		ctx->sample_start = ktime_get();
		mod_timer(&ctx->rpm_timer, jiffies + HZ);
	}

	hwmon = devm_hwmon_device_register_with_groups(dev, "pwmfan",
						       ctx, pwm_fan_groups);
	if (IS_ERR(hwmon)) {
		dev_err(dev, "Failed to register hwmon device\n");
		return PTR_ERR(hwmon);
	}

	ret = pwm_fan_of_get_cooling_data(dev, ctx);
	if (ret)
		return ret;

	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
	if (IS_ENABLED(CONFIG_THERMAL)) {
		cdev = devm_thermal_of_cooling_device_register(dev,
			dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
		if (IS_ERR(cdev)) {
			ret = PTR_ERR(cdev);
			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;
}

#ifdef CONFIG_PM_SLEEP
static int pwm_fan_suspend(struct device *dev)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	struct pwm_args args;
	int ret;

	pwm_get_args(ctx->pwm, &args);

	if (ctx->pwm_value) {
		ret = pwm_config(ctx->pwm, 0, args.period);
		if (ret < 0)
			return ret;

		pwm_disable(ctx->pwm);
	}

	if (ctx->reg_en) {
		ret = regulator_disable(ctx->reg_en);
		if (ret) {
			dev_err(dev, "Failed to disable fan supply: %d\n", ret);
			return ret;
		}
	}

	return 0;
}

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->reg_en) {
		ret = regulator_enable(ctx->reg_en);
		if (ret) {
			dev_err(dev, "Failed to enable fan supply: %d\n", ret);
			return 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);
}
#endif

static 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", },
	{},
};
MODULE_DEVICE_TABLE(of, of_pwm_fan_match);

static struct platform_driver pwm_fan_driver = {
	.probe		= pwm_fan_probe,
	.driver	= {
		.name		= "pwm-fan",
		.pm		= &pwm_fan_pm,
		.of_match_table	= of_pwm_fan_match,
	},
};

module_platform_driver(pwm_fan_driver);

MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
MODULE_ALIAS("platform:pwm-fan");
MODULE_DESCRIPTION("PWM FAN driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
c942fddf	1	// SPDX-License-Identifier: GPL-2.0-or-later
d82d5776 KD	2	/*
	3	* pwm-fan.c - Hwmon driver for fans connected to PWM lines.
	4	*
	5	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	6	*
	7	* Author: Kamil Debski <k.debski@samsung.com>
d82d5776 KD	8	*/
	9
	10	#include <linux/hwmon.h>
	11	#include <linux/hwmon-sysfs.h>
6b1ec478	12	#include <linux/interrupt.h>
d82d5776 KD	13	#include <linux/module.h>
	14	#include <linux/mutex.h>
	15	#include <linux/of.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/pwm.h>
b57e1d42	18	#include <linux/regulator/consumer.h>
d82d5776	19	#include <linux/sysfs.h>
b6bddec0	20	#include <linux/thermal.h>
6b1ec478	21	#include <linux/timer.h>
d82d5776 KD	22
	23	#define MAX_PWM 255
	24
	25	struct pwm_fan_ctx {
	26	struct mutex lock;
	27	struct pwm_device *pwm;
b57e1d42	28	struct regulator *reg_en;
6b1ec478 SW	29
	30	int irq;
	31	atomic_t pulses;
	32	unsigned int rpm;
	33	u8 pulses_per_revolution;
	34	ktime_t sample_start;
	35	struct timer_list rpm_timer;
	36
2e5219c7 LM	37	unsigned int pwm_value;
	38	unsigned int pwm_fan_state;
	39	unsigned int pwm_fan_max_state;
	40	unsigned int *pwm_fan_cooling_levels;
b6bddec0	41	struct thermal_cooling_device *cdev;
d82d5776 KD	42	};
d82d5776 KD	43
6b1ec478 SW	44	/* This handler assumes self resetting edge triggered interrupt. */
	45	static irqreturn_t pulse_handler(int irq, void *dev_id)
	46	{
	47	struct pwm_fan_ctx *ctx = dev_id;
	48
	49	atomic_inc(&ctx->pulses);
	50
	51	return IRQ_HANDLED;
	52	}
	53
	54	static void sample_timer(struct timer_list *t)
	55	{
	56	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
	57	int pulses;
	58	u64 tmp;
	59
	60	pulses = atomic_read(&ctx->pulses);
	61	atomic_sub(pulses, &ctx->pulses);
	62	tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60;
	63	do_div(tmp, ctx->pulses_per_revolution * 1000);
	64	ctx->rpm = tmp;
	65
	66	ctx->sample_start = ktime_get();
	67	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	68	}
	69
cb85ca33	70	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
d82d5776	71	{
677252a1	72	unsigned long period;
cb85ca33	73	int ret = 0;
677252a1	74	struct pwm_state state = { };
2289711c	75
d82d5776	76	mutex_lock(&ctx->lock);
d82d5776	77	if (ctx->pwm_value == pwm)
cb85ca33	78	goto exit_set_pwm_err;
d82d5776	79
677252a1 BZ	80	pwm_init_state(ctx->pwm, &state);
	81	period = ctx->pwm->args.period;
	82	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	83	state.enabled = pwm ? true : false;
f354169e	84
677252a1 BZ	85	ret = pwm_apply_state(ctx->pwm, &state);
	86	if (!ret)
	87	ctx->pwm_value = pwm;
d82d5776 KD	88	exit_set_pwm_err:
	89	mutex_unlock(&ctx->lock);
	90	return ret;
	91	}
	92
b6bddec0 LM	93	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	94	{
	95	int i;
	96
	97	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	98	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	99	break;
	100
	101	ctx->pwm_fan_state = i;
	102	}
	103
cb1d8534 GR	104	static ssize_t pwm_store(struct device dev, struct device_attribute attr,
cb1d8534 GR	105	const char *buf, size_t count)
cb85ca33 LM	106	{
	107	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	108	unsigned long pwm;
	109	int ret;
	110
	111	if (kstrtoul(buf, 10, &pwm) \|\| pwm > MAX_PWM)
	112	return -EINVAL;
	113
	114	ret = __set_pwm(ctx, pwm);
	115	if (ret)
	116	return ret;
	117
b6bddec0	118	pwm_fan_update_state(ctx, pwm);
cb85ca33 LM	119	return count;
	120	}
	121
cb1d8534 GR	122	static ssize_t pwm_show(struct device dev, struct device_attribute attr,
cb1d8534 GR	123	char *buf)
d82d5776 KD	124	{
	125	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	126
	127	return sprintf(buf, "%u\n", ctx->pwm_value);
	128	}
	129
6b1ec478 SW	130	static ssize_t rpm_show(struct device *dev,
	131	struct device_attribute attr, char buf)
	132	{
	133	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	134
	135	return sprintf(buf, "%u\n", ctx->rpm);
	136	}
d82d5776	137
cb1d8534	138	static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
6b1ec478	139	static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0);
d82d5776 KD	140
	141	static struct attribute *pwm_fan_attrs[] = {
	142	&sensor_dev_attr_pwm1.dev_attr.attr,
6b1ec478	143	&sensor_dev_attr_fan1_input.dev_attr.attr,
d82d5776 KD	144	NULL,
	145	};
	146
6b1ec478 SW	147	static umode_t pwm_fan_attrs_visible(struct kobject kobj, struct attribute a,
	148	int n)
	149	{
	150	struct device *dev = container_of(kobj, struct device, kobj);
	151	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	152
	153	/* Hide fan_input in case no interrupt is available */
	154	if (n == 1 && ctx->irq <= 0)
	155	return 0;
	156
	157	return a->mode;
	158	}
	159
	160	static const struct attribute_group pwm_fan_group = {
	161	.attrs = pwm_fan_attrs,
	162	.is_visible = pwm_fan_attrs_visible,
	163	};
	164
	165	static const struct attribute_group *pwm_fan_groups[] = {
	166	&pwm_fan_group,
	167	NULL,
	168	};
d82d5776	169
b6bddec0 LM	170	/* thermal cooling device callbacks */
	171	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	172	unsigned long *state)
	173	{
	174	struct pwm_fan_ctx *ctx = cdev->devdata;
	175
	176	if (!ctx)
	177	return -EINVAL;
	178
	179	*state = ctx->pwm_fan_max_state;
	180
	181	return 0;
	182	}
	183
	184	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	185	unsigned long *state)
	186	{
	187	struct pwm_fan_ctx *ctx = cdev->devdata;
	188
	189	if (!ctx)
	190	return -EINVAL;
	191
	192	*state = ctx->pwm_fan_state;
	193
	194	return 0;
	195	}
	196
	197	static int
	198	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	199	{
	200	struct pwm_fan_ctx *ctx = cdev->devdata;
	201	int ret;
	202
	203	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	204	return -EINVAL;
	205
	206	if (state == ctx->pwm_fan_state)
	207	return 0;
	208
	209	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	210	if (ret) {
	211	dev_err(&cdev->device, "Cannot set pwm!\n");
	212	return ret;
	213	}
	214
	215	ctx->pwm_fan_state = state;
	216
	217	return ret;
	218	}
	219
	220	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	221	.get_max_state = pwm_fan_get_max_state,
	222	.get_cur_state = pwm_fan_get_cur_state,
	223	.set_cur_state = pwm_fan_set_cur_state,
	224	};
	225
de52b049 GR	226	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	227	struct pwm_fan_ctx *ctx)
2e5219c7 LM	228	{
	229	struct device_node *np = dev->of_node;
	230	int num, i, ret;
	231
	232	if (!of_find_property(np, "cooling-levels", NULL))
	233	return 0;
	234
	235	ret = of_property_count_u32_elems(np, "cooling-levels");
	236	if (ret <= 0) {
	237	dev_err(dev, "Wrong data!\n");
	238	return ret ? : -EINVAL;
	239	}
	240
	241	num = ret;
a86854d0	242	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
2e5219c7 LM	243	GFP_KERNEL);
	244	if (!ctx->pwm_fan_cooling_levels)
	245	return -ENOMEM;
	246
	247	ret = of_property_read_u32_array(np, "cooling-levels",
	248	ctx->pwm_fan_cooling_levels, num);
	249	if (ret) {
	250	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	251	return ret;
	252	}
	253
	254	for (i = 0; i < num; i++) {
	255	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	256	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	257	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	258	return -EINVAL;
	259	}
	260	}
	261
	262	ctx->pwm_fan_max_state = num - 1;
	263
	264	return 0;
	265	}
	266
37bcec5d GR	267	static void pwm_fan_regulator_disable(void *data)
	268	{
	269	regulator_disable(data);
	270	}
	271
a455eda3	272	static void pwm_fan_pwm_disable(void *__ctx)
37bcec5d	273	{
a455eda3 LT	274	struct pwm_fan_ctx *ctx = __ctx;
	275	pwm_disable(ctx->pwm);
	276	del_timer_sync(&ctx->rpm_timer);
37bcec5d GR	277	}
37bcec5d GR	278
d82d5776 KD	279	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	280	{
b6bddec0	281	struct thermal_cooling_device *cdev;
37bcec5d	282	struct device *dev = &pdev->dev;
d82d5776	283	struct pwm_fan_ctx *ctx;
b6bddec0	284	struct device *hwmon;
d82d5776	285	int ret;
677252a1	286	struct pwm_state state = { };
6b1ec478	287	u32 ppr = 2;
d82d5776	288
37bcec5d	289	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
d82d5776 KD	290	if (!ctx)
	291	return -ENOMEM;
	292
	293	mutex_init(&ctx->lock);
	294
37bcec5d	295	ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
d82d5776	296	if (IS_ERR(ctx->pwm)) {
9f67f758 TR	297	ret = PTR_ERR(ctx->pwm);
	298
	299	if (ret != -EPROBE_DEFER)
37bcec5d	300	dev_err(dev, "Could not get PWM: %d\n", ret);
9f67f758 TR	301
9f67f758 TR	302	return ret;
d82d5776 KD	303	}
d82d5776 KD	304
d82d5776 KD	305	platform_set_drvdata(pdev, ctx);
d82d5776 KD	306
6b1ec478 SW	307	ctx->irq = platform_get_irq(pdev, 0);
	308	if (ctx->irq == -EPROBE_DEFER)
	309	return ctx->irq;
	310
37bcec5d	311	ctx->reg_en = devm_regulator_get_optional(dev, "fan");
b57e1d42 SW	312	if (IS_ERR(ctx->reg_en)) {
	313	if (PTR_ERR(ctx->reg_en) != -ENODEV)
	314	return PTR_ERR(ctx->reg_en);
	315
	316	ctx->reg_en = NULL;
	317	} else {
	318	ret = regulator_enable(ctx->reg_en);
	319	if (ret) {
37bcec5d	320	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
b57e1d42 SW	321	return ret;
b57e1d42 SW	322	}
37bcec5d GR	323	devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
37bcec5d GR	324	ctx->reg_en);
b57e1d42 SW	325	}
b57e1d42 SW	326
d82d5776 KD	327	ctx->pwm_value = MAX_PWM;
d82d5776 KD	328
677252a1 BZ	329	/* Set duty cycle to maximum allowed and enable PWM output */
	330	pwm_init_state(ctx->pwm, &state);
	331	state.duty_cycle = ctx->pwm->args.period - 1;
	332	state.enabled = true;
d82d5776	333
677252a1	334	ret = pwm_apply_state(ctx->pwm, &state);
d82d5776	335	if (ret) {
a455eda3	336	dev_err(dev, "Failed to configure PWM: %d\n", ret);
37bcec5d	337	return ret;
d82d5776	338	}
6b1ec478	339	timer_setup(&ctx->rpm_timer, sample_timer, 0);
a455eda3	340	devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
6b1ec478	341
a455eda3	342	of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);
6b1ec478 SW	343	ctx->pulses_per_revolution = ppr;
6b1ec478 SW	344	if (!ctx->pulses_per_revolution) {
a455eda3 LT	345	dev_err(dev, "pulses-per-revolution can't be zero.\n");
a455eda3 LT	346	return -EINVAL;
6b1ec478 SW	347	}
	348
	349	if (ctx->irq > 0) {
a455eda3	350	ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
6b1ec478 SW	351	pdev->name, ctx);
6b1ec478 SW	352	if (ret) {
a455eda3 LT	353	dev_err(dev, "Failed to request interrupt: %d\n", ret);
a455eda3 LT	354	return ret;
6b1ec478 SW	355	}
	356	ctx->sample_start = ktime_get();
	357	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	358	}
	359
37bcec5d	360	hwmon = devm_hwmon_device_register_with_groups(dev, "pwmfan",
d82d5776 KD	361	ctx, pwm_fan_groups);
d82d5776 KD	362	if (IS_ERR(hwmon)) {
37bcec5d GR	363	dev_err(dev, "Failed to register hwmon device\n");
37bcec5d GR	364	return PTR_ERR(hwmon);
d82d5776	365	}
2e5219c7	366
37bcec5d	367	ret = pwm_fan_of_get_cooling_data(dev, ctx);
2e5219c7 LM	368	if (ret)
	369	return ret;
	370
b6bddec0 LM	371	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
b6bddec0 LM	372	if (IS_ENABLED(CONFIG_THERMAL)) {
37bcec5d GR	373	cdev = devm_thermal_of_cooling_device_register(dev,
37bcec5d GR	374	dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
b6bddec0	375	if (IS_ERR(cdev)) {
677252a1	376	ret = PTR_ERR(cdev);
37bcec5d	377	dev_err(dev,
841cf676 RM	378	"Failed to register pwm-fan as cooling device: %d\n",
841cf676 RM	379	ret);
a455eda3	380	return ret;
b6bddec0 LM	381	}
	382	ctx->cdev = cdev;
	383	thermal_cdev_update(cdev);
	384	}
	385
d82d5776	386	return 0;
d82d5776 KD	387	}
	388
	389	#ifdef CONFIG_PM_SLEEP
	390	static int pwm_fan_suspend(struct device *dev)
	391	{
	392	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
95dcd64b TR	393	struct pwm_args args;
	394	int ret;
	395
	396	pwm_get_args(ctx->pwm, &args);
	397
	398	if (ctx->pwm_value) {
	399	ret = pwm_config(ctx->pwm, 0, args.period);
	400	if (ret < 0)
	401	return ret;
d82d5776	402
d82d5776	403	pwm_disable(ctx->pwm);
95dcd64b TR	404	}
95dcd64b TR	405
b57e1d42 SW	406	if (ctx->reg_en) {
	407	ret = regulator_disable(ctx->reg_en);
	408	if (ret) {
	409	dev_err(dev, "Failed to disable fan supply: %d\n", ret);
	410	return ret;
	411	}
	412	}
	413
d82d5776 KD	414	return 0;
	415	}
	416
	417	static int pwm_fan_resume(struct device *dev)
	418	{
	419	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
2289711c	420	struct pwm_args pargs;
48b9d5b4 KD	421	unsigned long duty;
48b9d5b4 KD	422	int ret;
d82d5776	423
b57e1d42 SW	424	if (ctx->reg_en) {
	425	ret = regulator_enable(ctx->reg_en);
	426	if (ret) {
	427	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
	428	return ret;
	429	}
	430	}
	431
48b9d5b4 KD	432	if (ctx->pwm_value == 0)
	433	return 0;
	434
2289711c BB	435	pwm_get_args(ctx->pwm, &pargs);
	436	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
	437	ret = pwm_config(ctx->pwm, duty, pargs.period);
48b9d5b4 KD	438	if (ret)
	439	return ret;
	440	return pwm_enable(ctx->pwm);
d82d5776 KD	441	}
	442	#endif
	443
	444	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	445
d720acac	446	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	447	{ .compatible = "pwm-fan", },
	448	{},
	449	};
f491e70c	450	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	451
	452	static struct platform_driver pwm_fan_driver = {
	453	.probe = pwm_fan_probe,
d82d5776 KD	454	.driver = {
	455	.name = "pwm-fan",
	456	.pm = &pwm_fan_pm,
	457	.of_match_table = of_pwm_fan_match,
	458	},
	459	};
	460
	461	module_platform_driver(pwm_fan_driver);
	462
	463	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	464	MODULE_ALIAS("platform:pwm-fan");
	465	MODULE_DESCRIPTION("PWM FAN driver");
	466	MODULE_LICENSE("GPL");