[linux-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;
};

static const u32 pwm_fan_channel_config_pwm[] = {
	HWMON_PWM_INPUT,
	0
};

static const struct hwmon_channel_info pwm_fan_channel_pwm = {
	.type = hwmon_pwm,
	.config = pwm_fan_channel_config_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 = 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] = &pwm_fan_channel_pwm;

	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	};
	51
	52	static const u32 pwm_fan_channel_config_pwm[] = {
	53	HWMON_PWM_INPUT,
	54	0
	55	};
	56
	57	static const struct hwmon_channel_info pwm_fan_channel_pwm = {
	58	.type = hwmon_pwm,
	59	.config = pwm_fan_channel_config_pwm,
	60	};
	61
6b1ec478 SW	62	/* This handler assumes self resetting edge triggered interrupt. */
	63	static irqreturn_t pulse_handler(int irq, void *dev_id)
	64	{
01695410	65	struct pwm_fan_tach *tach = dev_id;
6b1ec478	66
01695410	67	atomic_inc(&tach->pulses);
6b1ec478 SW	68
	69	return IRQ_HANDLED;
	70	}
	71
	72	static void sample_timer(struct timer_list *t)
	73	{
	74	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
fd8feec6	75	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
f0dc7cb6	76	int i;
6b1ec478	77
fd8feec6	78	if (delta) {
f0dc7cb6 PB	79	for (i = 0; i < ctx->tach_count; i++) {
	80	struct pwm_fan_tach *tach = &ctx->tachs[i];
	81	int pulses;
	82
	83	pulses = atomic_read(&tach->pulses);
	84	atomic_sub(pulses, &tach->pulses);
	85	tach->rpm = (unsigned int)(pulses * 1000 * 60) /
	86	(tach->pulses_per_revolution * delta);
	87	}
fd8feec6 PB	88
	89	ctx->sample_start = ktime_get();
	90	}
6b1ec478	91
6b1ec478 SW	92	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	93	}
	94
cb85ca33	95	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
d82d5776	96	{
677252a1	97	unsigned long period;
cb85ca33	98	int ret = 0;
86585c61	99	struct pwm_state *state = &ctx->pwm_state;
2289711c	100
d82d5776	101	mutex_lock(&ctx->lock);
d82d5776	102	if (ctx->pwm_value == pwm)
cb85ca33	103	goto exit_set_pwm_err;
d82d5776	104
86585c61 UKK	105	period = state->period;
	106	state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	107	state->enabled = pwm ? true : false;
f354169e	108
86585c61	109	ret = pwm_apply_state(ctx->pwm, state);
677252a1 BZ	110	if (!ret)
677252a1 BZ	111	ctx->pwm_value = pwm;
d82d5776 KD	112	exit_set_pwm_err:
	113	mutex_unlock(&ctx->lock);
	114	return ret;
	115	}
	116
b6bddec0 LM	117	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	118	{
	119	int i;
	120
	121	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	122	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	123	break;
	124
	125	ctx->pwm_fan_state = i;
	126	}
	127
1aa03655 PB	128	static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	129	u32 attr, int channel, long val)
cb85ca33 LM	130	{
cb85ca33 LM	131	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
cb85ca33 LM	132	int ret;
cb85ca33 LM	133
1aa03655	134	if (val < 0 \|\| val > MAX_PWM)
cb85ca33 LM	135	return -EINVAL;
cb85ca33 LM	136
1aa03655	137	ret = __set_pwm(ctx, val);
cb85ca33 LM	138	if (ret)
	139	return ret;
	140
1aa03655 PB	141	pwm_fan_update_state(ctx, val);
1aa03655 PB	142	return 0;
cb85ca33 LM	143	}
cb85ca33 LM	144
1aa03655 PB	145	static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	146	u32 attr, int channel, long *val)
d82d5776 KD	147	{
	148	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	149
1aa03655 PB	150	switch (type) {
	151	case hwmon_pwm:
	152	*val = ctx->pwm_value;
	153	return 0;
d82d5776	154
1aa03655	155	case hwmon_fan:
f0dc7cb6	156	*val = ctx->tachs[channel].rpm;
1aa03655	157	return 0;
6b1ec478	158
1aa03655 PB	159	default:
	160	return -ENOTSUPP;
	161	}
6b1ec478	162	}
d82d5776	163
1aa03655 PB	164	static umode_t pwm_fan_is_visible(const void *data,
	165	enum hwmon_sensor_types type,
	166	u32 attr, int channel)
6b1ec478	167	{
1aa03655 PB	168	switch (type) {
	169	case hwmon_pwm:
	170	return 0644;
6b1ec478	171
1aa03655 PB	172	case hwmon_fan:
1aa03655 PB	173	return 0444;
6b1ec478	174
1aa03655 PB	175	default:
	176	return 0;
	177	}
6b1ec478 SW	178	}
6b1ec478 SW	179
1aa03655 PB	180	static const struct hwmon_ops pwm_fan_hwmon_ops = {
	181	.is_visible = pwm_fan_is_visible,
	182	.read = pwm_fan_read,
	183	.write = pwm_fan_write,
6b1ec478	184	};
d82d5776	185
b6bddec0 LM	186	/* thermal cooling device callbacks */
	187	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	188	unsigned long *state)
	189	{
	190	struct pwm_fan_ctx *ctx = cdev->devdata;
	191
	192	if (!ctx)
	193	return -EINVAL;
	194
	195	*state = ctx->pwm_fan_max_state;
	196
	197	return 0;
	198	}
	199
	200	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	201	unsigned long *state)
	202	{
	203	struct pwm_fan_ctx *ctx = cdev->devdata;
	204
	205	if (!ctx)
	206	return -EINVAL;
	207
	208	*state = ctx->pwm_fan_state;
	209
	210	return 0;
	211	}
	212
	213	static int
	214	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	215	{
	216	struct pwm_fan_ctx *ctx = cdev->devdata;
	217	int ret;
	218
	219	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	220	return -EINVAL;
	221
	222	if (state == ctx->pwm_fan_state)
	223	return 0;
	224
	225	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	226	if (ret) {
	227	dev_err(&cdev->device, "Cannot set pwm!\n");
	228	return ret;
	229	}
	230
	231	ctx->pwm_fan_state = state;
	232
	233	return ret;
	234	}
	235
	236	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	237	.get_max_state = pwm_fan_get_max_state,
	238	.get_cur_state = pwm_fan_get_cur_state,
	239	.set_cur_state = pwm_fan_set_cur_state,
	240	};
	241
de52b049 GR	242	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	243	struct pwm_fan_ctx *ctx)
2e5219c7 LM	244	{
	245	struct device_node *np = dev->of_node;
	246	int num, i, ret;
	247
	248	if (!of_find_property(np, "cooling-levels", NULL))
	249	return 0;
	250
	251	ret = of_property_count_u32_elems(np, "cooling-levels");
	252	if (ret <= 0) {
	253	dev_err(dev, "Wrong data!\n");
	254	return ret ? : -EINVAL;
	255	}
	256
	257	num = ret;
a86854d0	258	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
2e5219c7 LM	259	GFP_KERNEL);
	260	if (!ctx->pwm_fan_cooling_levels)
	261	return -ENOMEM;
	262
	263	ret = of_property_read_u32_array(np, "cooling-levels",
	264	ctx->pwm_fan_cooling_levels, num);
	265	if (ret) {
	266	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	267	return ret;
	268	}
	269
	270	for (i = 0; i < num; i++) {
	271	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	272	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	273	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	274	return -EINVAL;
	275	}
	276	}
	277
	278	ctx->pwm_fan_max_state = num - 1;
	279
	280	return 0;
	281	}
	282
37bcec5d GR	283	static void pwm_fan_regulator_disable(void *data)
	284	{
	285	regulator_disable(data);
	286	}
	287
a455eda3	288	static void pwm_fan_pwm_disable(void *__ctx)
37bcec5d	289	{
a455eda3	290	struct pwm_fan_ctx *ctx = __ctx;
86585c61 UKK	291
	292	ctx->pwm_state.enabled = false;
	293	pwm_apply_state(ctx->pwm, &ctx->pwm_state);
a455eda3	294	del_timer_sync(&ctx->rpm_timer);
37bcec5d GR	295	}
37bcec5d GR	296
d82d5776 KD	297	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	298	{
b6bddec0	299	struct thermal_cooling_device *cdev;
37bcec5d	300	struct device *dev = &pdev->dev;
d82d5776	301	struct pwm_fan_ctx *ctx;
b6bddec0	302	struct device *hwmon;
d82d5776	303	int ret;
1aa03655	304	const struct hwmon_channel_info **channels;
f0dc7cb6 PB	305	u32 *fan_channel_config;
	306	int channel_count = 1; /* We always have a PWM channel. */
	307	int i;
d82d5776	308
37bcec5d	309	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
d82d5776 KD	310	if (!ctx)
	311	return -ENOMEM;
	312
	313	mutex_init(&ctx->lock);
	314
37bcec5d	315	ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
65b2aad0 AH	316	if (IS_ERR(ctx->pwm))
65b2aad0 AH	317	return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
d82d5776	318
d82d5776 KD	319	platform_set_drvdata(pdev, ctx);
d82d5776 KD	320
37bcec5d	321	ctx->reg_en = devm_regulator_get_optional(dev, "fan");
b57e1d42 SW	322	if (IS_ERR(ctx->reg_en)) {
	323	if (PTR_ERR(ctx->reg_en) != -ENODEV)
	324	return PTR_ERR(ctx->reg_en);
	325
	326	ctx->reg_en = NULL;
	327	} else {
	328	ret = regulator_enable(ctx->reg_en);
	329	if (ret) {
37bcec5d	330	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
b57e1d42 SW	331	return ret;
b57e1d42 SW	332	}
5696e4aa GR	333	ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
	334	ctx->reg_en);
	335	if (ret)
	336	return ret;
b57e1d42 SW	337	}
b57e1d42 SW	338
86585c61 UKK	339	pwm_init_state(ctx->pwm, &ctx->pwm_state);
86585c61 UKK	340
1eda5233 UKK	341	/*
	342	* __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
	343	* long. Check this here to prevent the fan running at a too low
	344	* frequency.
	345	*/
86585c61	346	if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
1eda5233 UKK	347	dev_err(dev, "Configured period too big\n");
	348	return -EINVAL;
	349	}
	350
	351	/* Set duty cycle to maximum allowed and enable PWM output */
86585c61	352	ret = __set_pwm(ctx, MAX_PWM);
d82d5776	353	if (ret) {
a455eda3	354	dev_err(dev, "Failed to configure PWM: %d\n", ret);
37bcec5d	355	return ret;
d82d5776	356	}
6b1ec478	357	timer_setup(&ctx->rpm_timer, sample_timer, 0);
5696e4aa GR	358	ret = devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
	359	if (ret)
	360	return ret;
6b1ec478	361
f0dc7cb6 PB	362	ctx->tach_count = platform_irq_count(pdev);
	363	if (ctx->tach_count < 0)
	364	return dev_err_probe(dev, ctx->tach_count,
b5fcb8a4	365	"Could not get number of fan tachometer inputs\n");
f0dc7cb6	366	dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
b5fcb8a4	367
f0dc7cb6 PB	368	if (ctx->tach_count) {
	369	channel_count++; /* We also have a FAN channel. */
	370
	371	ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
	372	sizeof(struct pwm_fan_tach),
	373	GFP_KERNEL);
	374	if (!ctx->tachs)
	375	return -ENOMEM;
	376
	377	ctx->fan_channel.type = hwmon_fan;
	378	fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
	379	sizeof(u32), GFP_KERNEL);
	380	if (!fan_channel_config)
	381	return -ENOMEM;
	382	ctx->fan_channel.config = fan_channel_config;
	383	}
	384
	385	channels = devm_kcalloc(dev, channel_count + 1,
1aa03655 PB	386	sizeof(struct hwmon_channel_info *), GFP_KERNEL);
	387	if (!channels)
	388	return -ENOMEM;
	389
	390	channels[0] = &pwm_fan_channel_pwm;
	391
f0dc7cb6 PB	392	for (i = 0; i < ctx->tach_count; i++) {
f0dc7cb6 PB	393	struct pwm_fan_tach *tach = &ctx->tachs[i];
b5fcb8a4 PB	394	u32 ppr = 2;
b5fcb8a4 PB	395
f0dc7cb6	396	tach->irq = platform_get_irq(pdev, i);
01695410 PB	397	if (tach->irq == -EPROBE_DEFER)
	398	return tach->irq;
	399	if (tach->irq > 0) {
	400	ret = devm_request_irq(dev, tach->irq, pulse_handler, 0,
	401	pdev->name, tach);
b5fcb8a4 PB	402	if (ret) {
	403	dev_err(dev,
	404	"Failed to request interrupt: %d\n",
	405	ret);
	406	return ret;
	407	}
	408	}
6b1ec478	409
f0dc7cb6 PB	410	of_property_read_u32_index(dev->of_node,
	411	"pulses-per-revolution",
	412	i,
	413	&ppr);
01695410 PB	414	tach->pulses_per_revolution = ppr;
01695410 PB	415	if (!tach->pulses_per_revolution) {
b5fcb8a4 PB	416	dev_err(dev, "pulses-per-revolution can't be zero.\n");
b5fcb8a4 PB	417	return -EINVAL;
6b1ec478	418	}
b5fcb8a4	419
f0dc7cb6 PB	420	fan_channel_config[i] = HWMON_F_INPUT;
	421
	422	dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
	423	i, tach->irq, tach->pulses_per_revolution);
	424	}
b5fcb8a4	425
f0dc7cb6	426	if (ctx->tach_count > 0) {
6b1ec478 SW	427	ctx->sample_start = ktime_get();
6b1ec478 SW	428	mod_timer(&ctx->rpm_timer, jiffies + HZ);
1aa03655	429
f0dc7cb6	430	channels[1] = &ctx->fan_channel;
6b1ec478 SW	431	}
6b1ec478 SW	432
1aa03655 PB	433	ctx->info.ops = &pwm_fan_hwmon_ops;
	434	ctx->info.info = channels;
	435
	436	hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
	437	ctx, &ctx->info, NULL);
d82d5776	438	if (IS_ERR(hwmon)) {
37bcec5d GR	439	dev_err(dev, "Failed to register hwmon device\n");
37bcec5d GR	440	return PTR_ERR(hwmon);
d82d5776	441	}
2e5219c7	442
37bcec5d	443	ret = pwm_fan_of_get_cooling_data(dev, ctx);
2e5219c7 LM	444	if (ret)
	445	return ret;
	446
b6bddec0 LM	447	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
b6bddec0 LM	448	if (IS_ENABLED(CONFIG_THERMAL)) {
37bcec5d GR	449	cdev = devm_thermal_of_cooling_device_register(dev,
37bcec5d GR	450	dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
b6bddec0	451	if (IS_ERR(cdev)) {
677252a1	452	ret = PTR_ERR(cdev);
37bcec5d	453	dev_err(dev,
841cf676 RM	454	"Failed to register pwm-fan as cooling device: %d\n",
841cf676 RM	455	ret);
a455eda3	456	return ret;
b6bddec0 LM	457	}
b6bddec0 LM	458	ctx->cdev = cdev;
b6bddec0 LM	459	}
b6bddec0 LM	460
d82d5776	461	return 0;
d82d5776 KD	462	}
d82d5776 KD	463
7992db7c	464	static int pwm_fan_disable(struct device *dev)
d82d5776 KD	465	{
d82d5776 KD	466	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
95dcd64b TR	467	int ret;
95dcd64b TR	468
95dcd64b	469	if (ctx->pwm_value) {
86585c61 UKK	470	/* keep ctx->pwm_state unmodified for pwm_fan_resume() */
	471	struct pwm_state state = ctx->pwm_state;
	472
	473	state.duty_cycle = 0;
	474	state.enabled = false;
	475	ret = pwm_apply_state(ctx->pwm, &state);
95dcd64b TR	476	if (ret < 0)
95dcd64b TR	477	return ret;
95dcd64b TR	478	}
95dcd64b TR	479
b57e1d42 SW	480	if (ctx->reg_en) {
	481	ret = regulator_disable(ctx->reg_en);
	482	if (ret) {
	483	dev_err(dev, "Failed to disable fan supply: %d\n", ret);
	484	return ret;
	485	}
	486	}
	487
d82d5776 KD	488	return 0;
	489	}
	490
7992db7c AM	491	static void pwm_fan_shutdown(struct platform_device *pdev)
	492	{
	493	pwm_fan_disable(&pdev->dev);
	494	}
	495
	496	#ifdef CONFIG_PM_SLEEP
	497	static int pwm_fan_suspend(struct device *dev)
	498	{
	499	return pwm_fan_disable(dev);
	500	}
	501
d82d5776 KD	502	static int pwm_fan_resume(struct device *dev)
	503	{
	504	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
48b9d5b4	505	int ret;
d82d5776	506
b57e1d42 SW	507	if (ctx->reg_en) {
	508	ret = regulator_enable(ctx->reg_en);
	509	if (ret) {
	510	dev_err(dev, "Failed to enable fan supply: %d\n", ret);
	511	return ret;
	512	}
	513	}
	514
48b9d5b4 KD	515	if (ctx->pwm_value == 0)
	516	return 0;
	517
86585c61	518	return pwm_apply_state(ctx->pwm, &ctx->pwm_state);
d82d5776 KD	519	}
	520	#endif
	521
	522	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	523
d720acac	524	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	525	{ .compatible = "pwm-fan", },
	526	{},
	527	};
f491e70c	528	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	529
	530	static struct platform_driver pwm_fan_driver = {
	531	.probe = pwm_fan_probe,
7992db7c	532	.shutdown = pwm_fan_shutdown,
d82d5776 KD	533	.driver = {
	534	.name = "pwm-fan",
	535	.pm = &pwm_fan_pm,
	536	.of_match_table = of_pwm_fan_match,
	537	},
	538	};
	539
	540	module_platform_driver(pwm_fan_driver);
	541
	542	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	543	MODULE_ALIAS("platform:pwm-fan");
	544	MODULE_DESCRIPTION("PWM FAN driver");
	545	MODULE_LICENSE("GPL");