[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/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_tach {
	int irq;
	atomic_t pulses;
	unsigned int rpm;
	u8 pulses_per_revolution;
};

struct pwm_fan_ctx {
	struct mutex lock;
	struct pwm_device *pwm;
	struct pwm_state pwm_state;
	struct regulator *reg_en;

	int tach_count;
	struct pwm_fan_tach *tachs;
	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;
};

/* 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 = from_timer(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) /
				(tach->pulses_per_revolution * delta);
		}

		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 = &ctx->pwm_state;

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

	period = state->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 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);
	int ret;

	if (val < 0 || val > MAX_PWM)
		return -EINVAL;

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

	pwm_fan_update_state(ctx, val);
	return 0;
}

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);

	switch (type) {
	case hwmon_pwm:
		*val = ctx->pwm_value;
		return 0;

	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;

	case hwmon_fan:
		return 0444;

	default:
		return 0;
	}
}

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,
				 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;

	ctx->pwm_state.enabled = false;
	pwm_apply_state(ctx->pwm, &ctx->pwm_state);
	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;
	const struct hwmon_channel_info **channels;
	u32 *fan_channel_config;
	int channel_count = 1;	/* We always have a PWM channel. */
	int i;

	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))
		return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");

	platform_set_drvdata(pdev, ctx);

	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;
		}
		ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
					       ctx->reg_en);
		if (ret)
			return ret;
	}

	pwm_init_state(ctx->pwm, &ctx->pwm_state);

	/*
	 * __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;
	}

	/* Set duty cycle to maximum allowed and enable PWM output */
	ret = __set_pwm(ctx, MAX_PWM);
	if (ret) {
		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_pwm_disable, ctx);
	if (ret)
		return ret;

	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;
	}

	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);

	for (i = 0; i < ctx->tach_count; i++) {
		struct pwm_fan_tach *tach = &ctx->tachs[i];
		u32 ppr = 2;

		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, 0,
					       pdev->name, tach);
			if (ret) {
				dev_err(dev,
					"Failed to request interrupt: %d\n",
					ret);
				return ret;
			}
		}

		of_property_read_u32_index(dev->of_node,
					   "pulses-per-revolution",
					   i,
					   &ppr);
		tach->pulses_per_revolution = ppr;
		if (!tach->pulses_per_revolution) {
			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, tach->pulses_per_revolution);
	}

	if (ctx->tach_count > 0) {
		ctx->sample_start = ktime_get();
		mod_timer(&ctx->rpm_timer, jiffies + HZ);

		channels[1] = &ctx->fan_channel;
	}

	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);
	}

	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;
	}

	return 0;
}

static int pwm_fan_disable(struct device *dev)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	int ret;

	if (ctx->pwm_value) {
		/* keep ctx->pwm_state unmodified for pwm_fan_resume() */
		struct pwm_state state = ctx->pwm_state;

		state.duty_cycle = 0;
		state.enabled = false;
		ret = pwm_apply_state(ctx->pwm, &state);
		if (ret < 0)
			return ret;
	}

	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 void pwm_fan_shutdown(struct platform_device *pdev)
{
	pwm_fan_disable(&pdev->dev);
}

#ifdef CONFIG_PM_SLEEP
static int pwm_fan_suspend(struct device *dev)
{
	return pwm_fan_disable(dev);
}

static int pwm_fan_resume(struct device *dev)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	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;

	return pwm_apply_state(ctx->pwm, &ctx->pwm_state);
}
#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,
	.shutdown	= pwm_fan_shutdown,
	.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>
6b1ec478	11	#include <linux/interrupt.h>
d82d5776 KD	12	#include <linux/module.h>
	13	#include <linux/mutex.h>
	14	#include <linux/of.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/pwm.h>
b57e1d42	17	#include <linux/regulator/consumer.h>
d82d5776	18	#include <linux/sysfs.h>
b6bddec0	19	#include <linux/thermal.h>
6b1ec478	20	#include <linux/timer.h>
d82d5776 KD	21
	22	#define MAX_PWM 255
	23
01695410 PB	24	struct pwm_fan_tach {
	25	int irq;
	26	atomic_t pulses;
	27	unsigned int rpm;
	28	u8 pulses_per_revolution;
	29	};
	30
d82d5776 KD	31	struct pwm_fan_ctx {
	32	struct mutex lock;
	33	struct pwm_device *pwm;
86585c61	34	struct pwm_state pwm_state;
b57e1d42	35	struct regulator *reg_en;
6b1ec478	36
f0dc7cb6 PB	37	int tach_count;
f0dc7cb6 PB	38	struct pwm_fan_tach *tachs;
6b1ec478 SW	39	ktime_t sample_start;
	40	struct timer_list rpm_timer;
	41
2e5219c7 LM	42	unsigned int pwm_value;
	43	unsigned int pwm_fan_state;
	44	unsigned int pwm_fan_max_state;
	45	unsigned int *pwm_fan_cooling_levels;
b6bddec0	46	struct thermal_cooling_device *cdev;
1aa03655 PB	47
1aa03655 PB	48	struct hwmon_chip_info info;
f0dc7cb6	49	struct hwmon_channel_info fan_channel;
1aa03655 PB	50	};
1aa03655 PB	51
6b1ec478 SW	52	/* This handler assumes self resetting edge triggered interrupt. */
	53	static irqreturn_t pulse_handler(int irq, void *dev_id)
	54	{
01695410	55	struct pwm_fan_tach *tach = dev_id;
6b1ec478	56
01695410	57	atomic_inc(&tach->pulses);
6b1ec478 SW	58
	59	return IRQ_HANDLED;
	60	}
	61
	62	static void sample_timer(struct timer_list *t)
	63	{
	64	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
fd8feec6	65	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
f0dc7cb6	66	int i;
6b1ec478	67
fd8feec6	68	if (delta) {
f0dc7cb6 PB	69	for (i = 0; i < ctx->tach_count; i++) {
	70	struct pwm_fan_tach *tach = &ctx->tachs[i];
	71	int pulses;
	72
	73	pulses = atomic_read(&tach->pulses);
	74	atomic_sub(pulses, &tach->pulses);
	75	tach->rpm = (unsigned int)(pulses * 1000 * 60) /
	76	(tach->pulses_per_revolution * delta);
	77	}
fd8feec6 PB	78
	79	ctx->sample_start = ktime_get();
	80	}
6b1ec478	81
6b1ec478 SW	82	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	83	}
	84
cb85ca33	85	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
d82d5776	86	{
677252a1	87	unsigned long period;
cb85ca33	88	int ret = 0;
86585c61	89	struct pwm_state *state = &ctx->pwm_state;
2289711c	90
d82d5776	91	mutex_lock(&ctx->lock);
d82d5776	92	if (ctx->pwm_value == pwm)
cb85ca33	93	goto exit_set_pwm_err;
d82d5776	94
86585c61 UKK	95	period = state->period;
	96	state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	97	state->enabled = pwm ? true : false;
f354169e	98
86585c61	99	ret = pwm_apply_state(ctx->pwm, state);
677252a1 BZ	100	if (!ret)
677252a1 BZ	101	ctx->pwm_value = pwm;
d82d5776 KD	102	exit_set_pwm_err:
	103	mutex_unlock(&ctx->lock);
	104	return ret;
	105	}
	106
b6bddec0 LM	107	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	108	{
	109	int i;
	110
	111	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	112	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	113	break;
	114
	115	ctx->pwm_fan_state = i;
	116	}
	117
1aa03655 PB	118	static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	119	u32 attr, int channel, long val)
cb85ca33 LM	120	{
cb85ca33 LM	121	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
cb85ca33 LM	122	int ret;
cb85ca33 LM	123
1aa03655	124	if (val < 0 \|\| val > MAX_PWM)
cb85ca33 LM	125	return -EINVAL;
cb85ca33 LM	126
1aa03655	127	ret = __set_pwm(ctx, val);
cb85ca33 LM	128	if (ret)
	129	return ret;
	130
1aa03655 PB	131	pwm_fan_update_state(ctx, val);
1aa03655 PB	132	return 0;
cb85ca33 LM	133	}
cb85ca33 LM	134
1aa03655 PB	135	static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	136	u32 attr, int channel, long *val)
d82d5776 KD	137	{
	138	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	139
1aa03655 PB	140	switch (type) {
	141	case hwmon_pwm:
	142	*val = ctx->pwm_value;
	143	return 0;
d82d5776	144
1aa03655	145	case hwmon_fan:
f0dc7cb6	146	*val = ctx->tachs[channel].rpm;
1aa03655	147	return 0;
6b1ec478	148
1aa03655 PB	149	default:
	150	return -ENOTSUPP;
	151	}
6b1ec478	152	}
d82d5776	153
1aa03655 PB	154	static umode_t pwm_fan_is_visible(const void *data,
	155	enum hwmon_sensor_types type,
	156	u32 attr, int channel)
6b1ec478	157	{
1aa03655 PB	158	switch (type) {
	159	case hwmon_pwm:
	160	return 0644;
6b1ec478	161
1aa03655 PB	162	case hwmon_fan:
1aa03655 PB	163	return 0444;
6b1ec478	164
1aa03655 PB	165	default:
	166	return 0;
	167	}
6b1ec478 SW	168	}
6b1ec478 SW	169
1aa03655 PB	170	static const struct hwmon_ops pwm_fan_hwmon_ops = {
	171	.is_visible = pwm_fan_is_visible,
	172	.read = pwm_fan_read,
	173	.write = pwm_fan_write,
6b1ec478	174	};
d82d5776	175
b6bddec0 LM	176	/* thermal cooling device callbacks */
	177	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	178	unsigned long *state)
	179	{
	180	struct pwm_fan_ctx *ctx = cdev->devdata;
	181
	182	if (!ctx)
	183	return -EINVAL;
	184
	185	*state = ctx->pwm_fan_max_state;
	186
	187	return 0;
	188	}
	189
	190	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	191	unsigned long *state)
	192	{
	193	struct pwm_fan_ctx *ctx = cdev->devdata;
	194
	195	if (!ctx)
	196	return -EINVAL;
	197
	198	*state = ctx->pwm_fan_state;
	199
	200	return 0;
	201	}
	202
	203	static int
	204	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	205	{
	206	struct pwm_fan_ctx *ctx = cdev->devdata;
	207	int ret;
	208
	209	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	210	return -EINVAL;
	211
	212	if (state == ctx->pwm_fan_state)
	213	return 0;
	214
	215	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	216	if (ret) {
	217	dev_err(&cdev->device, "Cannot set pwm!\n");
	218	return ret;
	219	}
	220
	221	ctx->pwm_fan_state = state;
	222
	223	return ret;
	224	}
	225
	226	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	227	.get_max_state = pwm_fan_get_max_state,
	228	.get_cur_state = pwm_fan_get_cur_state,
	229	.set_cur_state = pwm_fan_set_cur_state,
	230	};
	231
de52b049 GR	232	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	233	struct pwm_fan_ctx *ctx)
2e5219c7 LM	234	{
	235	struct device_node *np = dev->of_node;
	236	int num, i, ret;
	237
	238	if (!of_find_property(np, "cooling-levels", NULL))
	239	return 0;
	240
	241	ret = of_property_count_u32_elems(np, "cooling-levels");
	242	if (ret <= 0) {
	243	dev_err(dev, "Wrong data!\n");
	244	return ret ? : -EINVAL;
	245	}
	246
	247	num = ret;
a86854d0	248	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
2e5219c7 LM	249	GFP_KERNEL);
	250	if (!ctx->pwm_fan_cooling_levels)
	251	return -ENOMEM;
	252
	253	ret = of_property_read_u32_array(np, "cooling-levels",
	254	ctx->pwm_fan_cooling_levels, num);
	255	if (ret) {
	256	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	257	return ret;
	258	}
	259
	260	for (i = 0; i < num; i++) {
	261	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	262	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	263	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	264	return -EINVAL;
	265	}
	266	}
	267
	268	ctx->pwm_fan_max_state = num - 1;
	269
	270	return 0;
	271	}
	272
37bcec5d GR	273	static void pwm_fan_regulator_disable(void *data)
	274	{
	275	regulator_disable(data);
	276	}
	277
a455eda3	278	static void pwm_fan_pwm_disable(void *__ctx)
37bcec5d	279	{
a455eda3	280	struct pwm_fan_ctx *ctx = __ctx;
86585c61 UKK	281
	282	ctx->pwm_state.enabled = false;
	283	pwm_apply_state(ctx->pwm, &ctx->pwm_state);
a455eda3	284	del_timer_sync(&ctx->rpm_timer);
37bcec5d GR	285	}
37bcec5d GR	286
d82d5776 KD	287	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	288	{
b6bddec0	289	struct thermal_cooling_device *cdev;
37bcec5d	290	struct device *dev = &pdev->dev;
d82d5776	291	struct pwm_fan_ctx *ctx;
b6bddec0	292	struct device *hwmon;
d82d5776	293	int ret;
1aa03655	294	const struct hwmon_channel_info **channels;
f0dc7cb6 PB	295	u32 *fan_channel_config;
	296	int channel_count = 1; /* We always have a PWM channel. */
	297	int i;
d82d5776	298
37bcec5d	299	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
d82d5776 KD	300	if (!ctx)
	301	return -ENOMEM;
	302
	303	mutex_init(&ctx->lock);
	304
37bcec5d	305	ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
65b2aad0 AH	306	if (IS_ERR(ctx->pwm))
65b2aad0 AH	307	return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
d82d5776	308
d82d5776 KD	309	platform_set_drvdata(pdev, ctx);
d82d5776 KD	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	}
5696e4aa GR	323	ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
	324	ctx->reg_en);
	325	if (ret)
	326	return ret;
b57e1d42 SW	327	}
b57e1d42 SW	328
86585c61 UKK	329	pwm_init_state(ctx->pwm, &ctx->pwm_state);
86585c61 UKK	330
1eda5233 UKK	331	/*
	332	* __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
	333	* long. Check this here to prevent the fan running at a too low
	334	* frequency.
	335	*/
86585c61	336	if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
1eda5233 UKK	337	dev_err(dev, "Configured period too big\n");
	338	return -EINVAL;
	339	}
	340
	341	/* Set duty cycle to maximum allowed and enable PWM output */
86585c61	342	ret = __set_pwm(ctx, MAX_PWM);
d82d5776	343	if (ret) {
a455eda3	344	dev_err(dev, "Failed to configure PWM: %d\n", ret);
37bcec5d	345	return ret;
d82d5776	346	}
6b1ec478	347	timer_setup(&ctx->rpm_timer, sample_timer, 0);
5696e4aa GR	348	ret = devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
	349	if (ret)
	350	return ret;
6b1ec478	351
f0dc7cb6 PB	352	ctx->tach_count = platform_irq_count(pdev);
	353	if (ctx->tach_count < 0)
	354	return dev_err_probe(dev, ctx->tach_count,
b5fcb8a4	355	"Could not get number of fan tachometer inputs\n");
f0dc7cb6	356	dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
b5fcb8a4	357
f0dc7cb6 PB	358	if (ctx->tach_count) {
	359	channel_count++; /* We also have a FAN channel. */
	360
	361	ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
	362	sizeof(struct pwm_fan_tach),
	363	GFP_KERNEL);
	364	if (!ctx->tachs)
	365	return -ENOMEM;
	366
	367	ctx->fan_channel.type = hwmon_fan;
	368	fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
	369	sizeof(u32), GFP_KERNEL);
	370	if (!fan_channel_config)
	371	return -ENOMEM;
	372	ctx->fan_channel.config = fan_channel_config;
	373	}
	374
	375	channels = devm_kcalloc(dev, channel_count + 1,
1aa03655 PB	376	sizeof(struct hwmon_channel_info *), GFP_KERNEL);
	377	if (!channels)
	378	return -ENOMEM;
	379
7282d2ae	380	channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT);
1aa03655	381
f0dc7cb6 PB	382	for (i = 0; i < ctx->tach_count; i++) {
f0dc7cb6 PB	383	struct pwm_fan_tach *tach = &ctx->tachs[i];
b5fcb8a4 PB	384	u32 ppr = 2;
b5fcb8a4 PB	385
f0dc7cb6	386	tach->irq = platform_get_irq(pdev, i);
01695410 PB	387	if (tach->irq == -EPROBE_DEFER)
	388	return tach->irq;
	389	if (tach->irq > 0) {
	390	ret = devm_request_irq(dev, tach->irq, pulse_handler, 0,
	391	pdev->name, tach);
b5fcb8a4 PB	392	if (ret) {
	393	dev_err(dev,
	394	"Failed to request interrupt: %d\n",
	395	ret);
	396	return ret;
	397	}
	398	}
6b1ec478	399
f0dc7cb6 PB	400	of_property_read_u32_index(dev->of_node,
	401	"pulses-per-revolution",
	402	i,
	403	&ppr);
01695410 PB	404	tach->pulses_per_revolution = ppr;
01695410 PB	405	if (!tach->pulses_per_revolution) {
b5fcb8a4 PB	406	dev_err(dev, "pulses-per-revolution can't be zero.\n");
b5fcb8a4 PB	407	return -EINVAL;
6b1ec478	408	}
b5fcb8a4	409
f0dc7cb6 PB	410	fan_channel_config[i] = HWMON_F_INPUT;
	411
	412	dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
	413	i, tach->irq, tach->pulses_per_revolution);
	414	}
b5fcb8a4	415
f0dc7cb6	416	if (ctx->tach_count > 0) {
6b1ec478 SW	417	ctx->sample_start = ktime_get();
6b1ec478 SW	418	mod_timer(&ctx->rpm_timer, jiffies + HZ);
1aa03655	419
f0dc7cb6	420	channels[1] = &ctx->fan_channel;
6b1ec478 SW	421	}
6b1ec478 SW	422
1aa03655 PB	423	ctx->info.ops = &pwm_fan_hwmon_ops;
	424	ctx->info.info = channels;
	425
	426	hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
	427	ctx, &ctx->info, NULL);
d82d5776	428	if (IS_ERR(hwmon)) {
37bcec5d GR	429	dev_err(dev, "Failed to register hwmon device\n");
37bcec5d GR	430	return PTR_ERR(hwmon);
d82d5776	431	}
2e5219c7	432
37bcec5d	433	ret = pwm_fan_of_get_cooling_data(dev, ctx);
2e5219c7 LM	434	if (ret)
	435	return ret;
	436
b6bddec0 LM	437	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
b6bddec0 LM	438	if (IS_ENABLED(CONFIG_THERMAL)) {
37bcec5d GR	439	cdev = devm_thermal_of_cooling_device_register(dev,
37bcec5d GR	440	dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
b6bddec0	441	if (IS_ERR(cdev)) {
677252a1	442	ret = PTR_ERR(cdev);
37bcec5d	443	dev_err(dev,
841cf676 RM	444	"Failed to register pwm-fan as cooling device: %d\n",
841cf676 RM	445	ret);
a455eda3	446	return ret;
b6bddec0 LM	447	}
b6bddec0 LM	448	ctx->cdev = cdev;
b6bddec0 LM	449	}
b6bddec0 LM	450
d82d5776	451	return 0;
d82d5776 KD	452	}
d82d5776 KD	453
7992db7c	454	static int pwm_fan_disable(struct device *dev)
d82d5776 KD	455	{
d82d5776 KD	456	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
95dcd64b TR	457	int ret;
95dcd64b TR	458
95dcd64b	459	if (ctx->pwm_value) {
86585c61 UKK	460	/* keep ctx->pwm_state unmodified for pwm_fan_resume() */
	461	struct pwm_state state = ctx->pwm_state;
	462
	463	state.duty_cycle = 0;
	464	state.enabled = false;
	465	ret = pwm_apply_state(ctx->pwm, &state);
95dcd64b TR	466	if (ret < 0)
95dcd64b TR	467	return ret;
95dcd64b TR	468	}
95dcd64b TR	469
b57e1d42 SW	470	if (ctx->reg_en) {
	471	ret = regulator_disable(ctx->reg_en);
	472	if (ret) {
	473	dev_err(dev, "Failed to disable fan supply: %d\n", ret);
	474	return ret;
	475	}
	476	}
	477
d82d5776 KD	478	return 0;
	479	}
	480
7992db7c AM	481	static void pwm_fan_shutdown(struct platform_device *pdev)
	482	{
	483	pwm_fan_disable(&pdev->dev);
	484	}
	485
	486	#ifdef CONFIG_PM_SLEEP
	487	static int pwm_fan_suspend(struct device *dev)
	488	{
	489	return pwm_fan_disable(dev);
	490	}
	491
d82d5776 KD	492	static int pwm_fan_resume(struct device *dev)
	493	{
	494	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
48b9d5b4	495	int ret;
d82d5776	496
b57e1d42 SW	497	if (ctx->reg_en) {
	498	ret = regulator_enable(ctx->reg_en);
	499	if (ret) {
	500	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
	501	return ret;
	502	}
	503	}
	504
48b9d5b4 KD	505	if (ctx->pwm_value == 0)
	506	return 0;
	507
86585c61	508	return pwm_apply_state(ctx->pwm, &ctx->pwm_state);
d82d5776 KD	509	}
	510	#endif
	511
	512	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	513
d720acac	514	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	515	{ .compatible = "pwm-fan", },
	516	{},
	517	};
f491e70c	518	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	519
	520	static struct platform_driver pwm_fan_driver = {
	521	.probe = pwm_fan_probe,
7992db7c	522	.shutdown = pwm_fan_shutdown,
d82d5776 KD	523	.driver = {
	524	.name = "pwm-fan",
	525	.pm = &pwm_fan_pm,
	526	.of_match_table = of_pwm_fan_match,
	527	},
	528	};
	529
	530	module_platform_driver(pwm_fan_driver);
	531
	532	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	533	MODULE_ALIAS("platform:pwm-fan");
	534	MODULE_DESCRIPTION("PWM FAN driver");
	535	MODULE_LICENSE("GPL");