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

/*
 * 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/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 int pwm_fan_probe(struct platform_device *pdev)
{
	struct thermal_cooling_device *cdev;
	struct pwm_fan_ctx *ctx;
	struct device *hwmon;
	int ret;
	struct pwm_state state = { };
	u32 ppr = 2;

	ctx = devm_kzalloc(&pdev->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)) {
		ret = PTR_ERR(ctx->pwm);

		if (ret != -EPROBE_DEFER)
			dev_err(&pdev->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(&pdev->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(&pdev->dev,
				"Failed to enable fan supply: %d\n", ret);
			return ret;
		}
	}

	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(&pdev->dev, "Failed to configure PWM: %d\n", ret);
		goto err_reg_disable;
	}

	timer_setup(&ctx->rpm_timer, sample_timer, 0);

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

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

	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
						       ctx, pwm_fan_groups);
	if (IS_ERR(hwmon)) {
		ret = PTR_ERR(hwmon);
		dev_err(&pdev->dev,
			"Failed to register hwmon device: %d\n", ret);
		goto err_del_timer;
	}

	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
	if (ret)
		goto err_del_timer;

	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);
		if (IS_ERR(cdev)) {
			ret = PTR_ERR(cdev);
			dev_err(&pdev->dev,
				"Failed to register pwm-fan as cooling device: %d\n",
				ret);
			goto err_del_timer;
		}
		ctx->cdev = cdev;
		thermal_cdev_update(cdev);
	}

	return 0;

err_del_timer:
	del_timer_sync(&ctx->rpm_timer);

err_pwm_disable:
	state.enabled = false;
	pwm_apply_state(ctx->pwm, &state);

err_reg_disable:
	if (ctx->reg_en)
		regulator_disable(ctx->reg_en);

	return ret;
}

static int pwm_fan_remove(struct platform_device *pdev)
{
	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);

	thermal_cooling_device_unregister(ctx->cdev);
	del_timer_sync(&ctx->rpm_timer);

	if (ctx->pwm_value)
		pwm_disable(ctx->pwm);

	if (ctx->reg_en)
		regulator_disable(ctx->reg_en);

	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,
	.remove		= pwm_fan_remove,
	.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
d82d5776 KD	1	/*
	2	* pwm-fan.c - Hwmon driver for fans connected to PWM lines.
	3	*
	4	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	5	*
	6	* Author: Kamil Debski <k.debski@samsung.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*/
	18
	19	#include <linux/hwmon.h>
	20	#include <linux/hwmon-sysfs.h>
6b1ec478	21	#include <linux/interrupt.h>
d82d5776 KD	22	#include <linux/module.h>
	23	#include <linux/mutex.h>
	24	#include <linux/of.h>
	25	#include <linux/platform_device.h>
	26	#include <linux/pwm.h>
b57e1d42	27	#include <linux/regulator/consumer.h>
d82d5776	28	#include <linux/sysfs.h>
b6bddec0	29	#include <linux/thermal.h>
6b1ec478	30	#include <linux/timer.h>
d82d5776 KD	31
	32	#define MAX_PWM 255
	33
	34	struct pwm_fan_ctx {
	35	struct mutex lock;
	36	struct pwm_device *pwm;
b57e1d42	37	struct regulator *reg_en;
6b1ec478 SW	38
	39	int irq;
	40	atomic_t pulses;
	41	unsigned int rpm;
	42	u8 pulses_per_revolution;
	43	ktime_t sample_start;
	44	struct timer_list rpm_timer;
	45
2e5219c7 LM	46	unsigned int pwm_value;
	47	unsigned int pwm_fan_state;
	48	unsigned int pwm_fan_max_state;
	49	unsigned int *pwm_fan_cooling_levels;
b6bddec0	50	struct thermal_cooling_device *cdev;
d82d5776 KD	51	};
d82d5776 KD	52
6b1ec478 SW	53	/* This handler assumes self resetting edge triggered interrupt. */
	54	static irqreturn_t pulse_handler(int irq, void *dev_id)
	55	{
	56	struct pwm_fan_ctx *ctx = dev_id;
	57
	58	atomic_inc(&ctx->pulses);
	59
	60	return IRQ_HANDLED;
	61	}
	62
	63	static void sample_timer(struct timer_list *t)
	64	{
	65	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
	66	int pulses;
	67	u64 tmp;
	68
	69	pulses = atomic_read(&ctx->pulses);
	70	atomic_sub(pulses, &ctx->pulses);
	71	tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60;
	72	do_div(tmp, ctx->pulses_per_revolution * 1000);
	73	ctx->rpm = tmp;
	74
	75	ctx->sample_start = ktime_get();
	76	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	77	}
	78
cb85ca33	79	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
d82d5776	80	{
677252a1	81	unsigned long period;
cb85ca33	82	int ret = 0;
677252a1	83	struct pwm_state state = { };
2289711c	84
d82d5776	85	mutex_lock(&ctx->lock);
d82d5776	86	if (ctx->pwm_value == pwm)
cb85ca33	87	goto exit_set_pwm_err;
d82d5776	88
677252a1 BZ	89	pwm_init_state(ctx->pwm, &state);
	90	period = ctx->pwm->args.period;
	91	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	92	state.enabled = pwm ? true : false;
f354169e	93
677252a1 BZ	94	ret = pwm_apply_state(ctx->pwm, &state);
	95	if (!ret)
	96	ctx->pwm_value = pwm;
d82d5776 KD	97	exit_set_pwm_err:
	98	mutex_unlock(&ctx->lock);
	99	return ret;
	100	}
	101
b6bddec0 LM	102	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	103	{
	104	int i;
	105
	106	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	107	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	108	break;
	109
	110	ctx->pwm_fan_state = i;
	111	}
	112
cb1d8534 GR	113	static ssize_t pwm_store(struct device dev, struct device_attribute attr,
cb1d8534 GR	114	const char *buf, size_t count)
cb85ca33 LM	115	{
	116	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	117	unsigned long pwm;
	118	int ret;
	119
	120	if (kstrtoul(buf, 10, &pwm) \|\| pwm > MAX_PWM)
	121	return -EINVAL;
	122
	123	ret = __set_pwm(ctx, pwm);
	124	if (ret)
	125	return ret;
	126
b6bddec0	127	pwm_fan_update_state(ctx, pwm);
cb85ca33 LM	128	return count;
	129	}
	130
cb1d8534 GR	131	static ssize_t pwm_show(struct device dev, struct device_attribute attr,
cb1d8534 GR	132	char *buf)
d82d5776 KD	133	{
	134	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	135
	136	return sprintf(buf, "%u\n", ctx->pwm_value);
	137	}
	138
6b1ec478 SW	139	static ssize_t rpm_show(struct device *dev,
	140	struct device_attribute attr, char buf)
	141	{
	142	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	143
	144	return sprintf(buf, "%u\n", ctx->rpm);
	145	}
d82d5776	146
cb1d8534	147	static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
6b1ec478	148	static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0);
d82d5776 KD	149
	150	static struct attribute *pwm_fan_attrs[] = {
	151	&sensor_dev_attr_pwm1.dev_attr.attr,
6b1ec478	152	&sensor_dev_attr_fan1_input.dev_attr.attr,
d82d5776 KD	153	NULL,
	154	};
	155
6b1ec478 SW	156	static umode_t pwm_fan_attrs_visible(struct kobject kobj, struct attribute a,
	157	int n)
	158	{
	159	struct device *dev = container_of(kobj, struct device, kobj);
	160	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	161
	162	/* Hide fan_input in case no interrupt is available */
	163	if (n == 1 && ctx->irq <= 0)
	164	return 0;
	165
	166	return a->mode;
	167	}
	168
	169	static const struct attribute_group pwm_fan_group = {
	170	.attrs = pwm_fan_attrs,
	171	.is_visible = pwm_fan_attrs_visible,
	172	};
	173
	174	static const struct attribute_group *pwm_fan_groups[] = {
	175	&pwm_fan_group,
	176	NULL,
	177	};
d82d5776	178
b6bddec0 LM	179	/* thermal cooling device callbacks */
	180	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	181	unsigned long *state)
	182	{
	183	struct pwm_fan_ctx *ctx = cdev->devdata;
	184
	185	if (!ctx)
	186	return -EINVAL;
	187
	188	*state = ctx->pwm_fan_max_state;
	189
	190	return 0;
	191	}
	192
	193	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	194	unsigned long *state)
	195	{
	196	struct pwm_fan_ctx *ctx = cdev->devdata;
	197
	198	if (!ctx)
	199	return -EINVAL;
	200
	201	*state = ctx->pwm_fan_state;
	202
	203	return 0;
	204	}
	205
	206	static int
	207	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	208	{
	209	struct pwm_fan_ctx *ctx = cdev->devdata;
	210	int ret;
	211
	212	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	213	return -EINVAL;
	214
	215	if (state == ctx->pwm_fan_state)
	216	return 0;
	217
	218	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	219	if (ret) {
	220	dev_err(&cdev->device, "Cannot set pwm!\n");
	221	return ret;
	222	}
	223
	224	ctx->pwm_fan_state = state;
	225
	226	return ret;
	227	}
	228
	229	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	230	.get_max_state = pwm_fan_get_max_state,
	231	.get_cur_state = pwm_fan_get_cur_state,
	232	.set_cur_state = pwm_fan_set_cur_state,
	233	};
	234
de52b049 GR	235	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	236	struct pwm_fan_ctx *ctx)
2e5219c7 LM	237	{
	238	struct device_node *np = dev->of_node;
	239	int num, i, ret;
	240
	241	if (!of_find_property(np, "cooling-levels", NULL))
	242	return 0;
	243
	244	ret = of_property_count_u32_elems(np, "cooling-levels");
	245	if (ret <= 0) {
	246	dev_err(dev, "Wrong data!\n");
	247	return ret ? : -EINVAL;
	248	}
	249
	250	num = ret;
a86854d0	251	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
2e5219c7 LM	252	GFP_KERNEL);
	253	if (!ctx->pwm_fan_cooling_levels)
	254	return -ENOMEM;
	255
	256	ret = of_property_read_u32_array(np, "cooling-levels",
	257	ctx->pwm_fan_cooling_levels, num);
	258	if (ret) {
	259	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	260	return ret;
	261	}
	262
	263	for (i = 0; i < num; i++) {
	264	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	265	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	266	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	267	return -EINVAL;
	268	}
	269	}
	270
	271	ctx->pwm_fan_max_state = num - 1;
	272
	273	return 0;
	274	}
	275
d82d5776 KD	276	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	277	{
b6bddec0	278	struct thermal_cooling_device *cdev;
d82d5776	279	struct pwm_fan_ctx *ctx;
b6bddec0	280	struct device *hwmon;
d82d5776	281	int ret;
677252a1	282	struct pwm_state state = { };
6b1ec478	283	u32 ppr = 2;
d82d5776 KD	284
	285	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
	286	if (!ctx)
	287	return -ENOMEM;
	288
	289	mutex_init(&ctx->lock);
	290
	291	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
	292	if (IS_ERR(ctx->pwm)) {
9f67f758 TR	293	ret = PTR_ERR(ctx->pwm);
	294
	295	if (ret != -EPROBE_DEFER)
	296	dev_err(&pdev->dev, "Could not get PWM: %d\n", ret);
	297
	298	return ret;
d82d5776 KD	299	}
d82d5776 KD	300
d82d5776 KD	301	platform_set_drvdata(pdev, ctx);
d82d5776 KD	302
6b1ec478 SW	303	ctx->irq = platform_get_irq(pdev, 0);
	304	if (ctx->irq == -EPROBE_DEFER)
	305	return ctx->irq;
	306
b57e1d42 SW	307	ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan");
	308	if (IS_ERR(ctx->reg_en)) {
	309	if (PTR_ERR(ctx->reg_en) != -ENODEV)
	310	return PTR_ERR(ctx->reg_en);
	311
	312	ctx->reg_en = NULL;
	313	} else {
	314	ret = regulator_enable(ctx->reg_en);
	315	if (ret) {
	316	dev_err(&pdev->dev,
	317	"Failed to enable fan supply: %d\n", ret);
	318	return ret;
	319	}
	320	}
	321
d82d5776 KD	322	ctx->pwm_value = MAX_PWM;
d82d5776 KD	323
677252a1 BZ	324	/* Set duty cycle to maximum allowed and enable PWM output */
	325	pwm_init_state(ctx->pwm, &state);
	326	state.duty_cycle = ctx->pwm->args.period - 1;
	327	state.enabled = true;
d82d5776	328
677252a1	329	ret = pwm_apply_state(ctx->pwm, &state);
d82d5776	330	if (ret) {
841cf676	331	dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret);
b57e1d42	332	goto err_reg_disable;
d82d5776 KD	333	}
d82d5776 KD	334
6b1ec478 SW	335	timer_setup(&ctx->rpm_timer, sample_timer, 0);
	336
	337	of_property_read_u32(pdev->dev.of_node, "pulses-per-revolution", &ppr);
	338	ctx->pulses_per_revolution = ppr;
	339	if (!ctx->pulses_per_revolution) {
	340	dev_err(&pdev->dev, "pulses-per-revolution can't be zero.\n");
	341	ret = -EINVAL;
	342	goto err_pwm_disable;
	343	}
	344
	345	if (ctx->irq > 0) {
	346	ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0,
	347	pdev->name, ctx);
	348	if (ret) {
841cf676 RM	349	dev_err(&pdev->dev,
841cf676 RM	350	"Failed to request interrupt: %d\n", ret);
6b1ec478 SW	351	goto err_pwm_disable;
	352	}
	353	ctx->sample_start = ktime_get();
	354	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	355	}
	356
d82d5776 KD	357	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
	358	ctx, pwm_fan_groups);
	359	if (IS_ERR(hwmon)) {
677252a1	360	ret = PTR_ERR(hwmon);
841cf676 RM	361	dev_err(&pdev->dev,
841cf676 RM	362	"Failed to register hwmon device: %d\n", ret);
6b1ec478	363	goto err_del_timer;
d82d5776	364	}
2e5219c7 LM	365
	366	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
	367	if (ret)
6b1ec478	368	goto err_del_timer;
2e5219c7	369
b6bddec0 LM	370	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
	371	if (IS_ENABLED(CONFIG_THERMAL)) {
	372	cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
	373	"pwm-fan", ctx,
	374	&pwm_fan_cooling_ops);
	375	if (IS_ERR(cdev)) {
677252a1	376	ret = PTR_ERR(cdev);
841cf676 RM	377	dev_err(&pdev->dev,
	378	"Failed to register pwm-fan as cooling device: %d\n",
	379	ret);
6b1ec478	380	goto err_del_timer;
b6bddec0 LM	381	}
	382	ctx->cdev = cdev;
	383	thermal_cdev_update(cdev);
	384	}
	385
d82d5776	386	return 0;
677252a1	387
6b1ec478 SW	388	err_del_timer:
	389	del_timer_sync(&ctx->rpm_timer);
	390
677252a1 BZ	391	err_pwm_disable:
	392	state.enabled = false;
	393	pwm_apply_state(ctx->pwm, &state);
	394
b57e1d42 SW	395	err_reg_disable:
	396	if (ctx->reg_en)
	397	regulator_disable(ctx->reg_en);
	398
677252a1	399	return ret;
d82d5776 KD	400	}
	401
	402	static int pwm_fan_remove(struct platform_device *pdev)
	403	{
	404	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
	405
b6bddec0	406	thermal_cooling_device_unregister(ctx->cdev);
6b1ec478 SW	407	del_timer_sync(&ctx->rpm_timer);
6b1ec478 SW	408
d82d5776 KD	409	if (ctx->pwm_value)
d82d5776 KD	410	pwm_disable(ctx->pwm);
b57e1d42 SW	411
	412	if (ctx->reg_en)
	413	regulator_disable(ctx->reg_en);
	414
d82d5776 KD	415	return 0;
	416	}
	417
	418	#ifdef CONFIG_PM_SLEEP
	419	static int pwm_fan_suspend(struct device *dev)
	420	{
	421	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
95dcd64b TR	422	struct pwm_args args;
	423	int ret;
	424
	425	pwm_get_args(ctx->pwm, &args);
	426
	427	if (ctx->pwm_value) {
	428	ret = pwm_config(ctx->pwm, 0, args.period);
	429	if (ret < 0)
	430	return ret;
d82d5776	431
d82d5776	432	pwm_disable(ctx->pwm);
95dcd64b TR	433	}
95dcd64b TR	434
b57e1d42 SW	435	if (ctx->reg_en) {
	436	ret = regulator_disable(ctx->reg_en);
	437	if (ret) {
	438	dev_err(dev, "Failed to disable fan supply: %d\n", ret);
	439	return ret;
	440	}
	441	}
	442
d82d5776 KD	443	return 0;
	444	}
	445
	446	static int pwm_fan_resume(struct device *dev)
	447	{
	448	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
2289711c	449	struct pwm_args pargs;
48b9d5b4 KD	450	unsigned long duty;
48b9d5b4 KD	451	int ret;
d82d5776	452
b57e1d42 SW	453	if (ctx->reg_en) {
	454	ret = regulator_enable(ctx->reg_en);
	455	if (ret) {
	456	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
	457	return ret;
	458	}
	459	}
	460
48b9d5b4 KD	461	if (ctx->pwm_value == 0)
	462	return 0;
	463
2289711c BB	464	pwm_get_args(ctx->pwm, &pargs);
	465	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
	466	ret = pwm_config(ctx->pwm, duty, pargs.period);
48b9d5b4 KD	467	if (ret)
	468	return ret;
	469	return pwm_enable(ctx->pwm);
d82d5776 KD	470	}
	471	#endif
	472
	473	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	474
d720acac	475	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	476	{ .compatible = "pwm-fan", },
	477	{},
	478	};
f491e70c	479	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	480
	481	static struct platform_driver pwm_fan_driver = {
	482	.probe = pwm_fan_probe,
	483	.remove = pwm_fan_remove,
	484	.driver = {
	485	.name = "pwm-fan",
	486	.pm = &pwm_fan_pm,
	487	.of_match_table = of_pwm_fan_match,
	488	},
	489	};
	490
	491	module_platform_driver(pwm_fan_driver);
	492
	493	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	494	MODULE_ALIAS("platform:pwm-fan");
	495	MODULE_DESCRIPTION("PWM FAN driver");
	496	MODULE_LICENSE("GPL");