[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;
};

enum pwm_fan_enable_mode {
	pwm_off_reg_off,
	pwm_disable_reg_enable,
	pwm_enable_reg_enable,
	pwm_disable_reg_disable,
};

struct pwm_fan_ctx {
	struct device *dev;

	struct mutex lock;
	struct pwm_device *pwm;
	struct pwm_state pwm_state;
	struct regulator *reg_en;
	enum pwm_fan_enable_mode enable_mode;
	bool regulator_enabled;
	bool enabled;

	int tach_count;
	struct pwm_fan_tach *tachs;
	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 void pwm_fan_enable_mode_2_state(int enable_mode,
					struct pwm_state *state,
					bool *enable_regulator)
{
	switch (enable_mode) {
	case pwm_disable_reg_enable:
		/* disable pwm, keep regulator enabled */
		state->enabled = false;
		*enable_regulator = true;
		break;
	case pwm_enable_reg_enable:
		/* keep pwm and regulator enabled */
		state->enabled = true;
		*enable_regulator = true;
		break;
	case pwm_off_reg_off:
	case pwm_disable_reg_disable:
		/* disable pwm and regulator */
		state->enabled = false;
		*enable_regulator = false;
	}
}

static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
{
	int ret = 0;

	if (!ctx->reg_en)
		return ret;

	if (!ctx->regulator_enabled && on) {
		ret = regulator_enable(ctx->reg_en);
		if (ret == 0)
			ctx->regulator_enabled = true;
	} else if (ctx->regulator_enabled && !on) {
		ret = regulator_disable(ctx->reg_en);
		if (ret == 0)
			ctx->regulator_enabled = false;
	}
	return ret;
}

static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
{
	struct pwm_state *state = &ctx->pwm_state;
	int ret;

	if (ctx->enabled)
		return 0;

	ret = pwm_fan_switch_power(ctx, true);
	if (ret < 0) {
		dev_err(ctx->dev, "failed to enable power supply\n");
		return ret;
	}

	state->enabled = true;
	ret = pwm_apply_state(ctx->pwm, state);
	if (ret) {
		dev_err(ctx->dev, "failed to enable PWM\n");
		goto disable_regulator;
	}

	ctx->enabled = true;

	return 0;

disable_regulator:
	pwm_fan_switch_power(ctx, false);
	return ret;
}

static int pwm_fan_power_off(struct pwm_fan_ctx *ctx)
{
	struct pwm_state *state = &ctx->pwm_state;
	bool enable_regulator = false;
	int ret;

	if (!ctx->enabled)
		return 0;

	pwm_fan_enable_mode_2_state(ctx->enable_mode,
				    state,
				    &enable_regulator);

	state->enabled = false;
	state->duty_cycle = 0;
	ret = pwm_apply_state(ctx->pwm, state);
	if (ret) {
		dev_err(ctx->dev, "failed to disable PWM\n");
		return ret;
	}

	pwm_fan_switch_power(ctx, enable_regulator);

	ctx->enabled = false;

	return 0;
}

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

	if (pwm > 0) {
		if (ctx->enable_mode == pwm_off_reg_off)
			/* pwm-fan hard disabled */
			return 0;

		period = state->period;
		state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
		ret = pwm_apply_state(ctx->pwm, state);
		if (ret)
			return ret;
		ret = pwm_fan_power_on(ctx);
	} else {
		ret = pwm_fan_power_off(ctx);
	}
	if (!ret)
		ctx->pwm_value = pwm;

	return ret;
}

static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
	int ret;

	mutex_lock(&ctx->lock);
	ret = __set_pwm(ctx, pwm);
	mutex_unlock(&ctx->lock);

	return ret;
}

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_update_enable(struct pwm_fan_ctx *ctx, long val)
{
	int ret = 0;
	int old_val;

	mutex_lock(&ctx->lock);

	if (ctx->enable_mode == val)
		goto out;

	old_val = ctx->enable_mode;
	ctx->enable_mode = val;

	if (val == 0) {
		/* Disable pwm-fan unconditionally */
		if (ctx->enabled)
			ret = __set_pwm(ctx, 0);
		else
			ret = pwm_fan_switch_power(ctx, false);
		if (ret)
			ctx->enable_mode = old_val;
		pwm_fan_update_state(ctx, 0);
	} else {
		/*
		 * Change PWM and/or regulator state if currently disabled
		 * Nothing to do if currently enabled
		 */
		if (!ctx->enabled) {
			struct pwm_state *state = &ctx->pwm_state;
			bool enable_regulator = false;

			state->duty_cycle = 0;
			pwm_fan_enable_mode_2_state(val,
						    state,
						    &enable_regulator);

			pwm_apply_state(ctx->pwm, state);
			pwm_fan_switch_power(ctx, enable_regulator);
			pwm_fan_update_state(ctx, 0);
		}
	}
out:
	mutex_unlock(&ctx->lock);

	return ret;
}

static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long val)
{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	int ret;

	switch (attr) {
	case hwmon_pwm_input:
		if (val < 0 || val > MAX_PWM)
			return -EINVAL;
		ret = set_pwm(ctx, val);
		if (ret)
			return ret;
		pwm_fan_update_state(ctx, val);
		break;
	case hwmon_pwm_enable:
		if (val < 0 || val > 3)
			ret = -EINVAL;
		else
			ret = pwm_fan_update_enable(ctx, val);

		return ret;
	default:
		return -EOPNOTSUPP;
	}

	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:
		switch (attr) {
		case hwmon_pwm_input:
			*val = ctx->pwm_value;
			return 0;
		case hwmon_pwm_enable:
			*val = ctx->enable_mode;
			return 0;
		}
		return -EOPNOTSUPP;
	case hwmon_fan:
		*val = ctx->tachs[channel].rpm;
		return 0;

	default:
		return -ENOTSUPP;
	}
}

static umode_t pwm_fan_is_visible(const void *data,
				  enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	switch (type) {
	case hwmon_pwm:
		return 0644;

	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_property_present(np, "cooling-levels"))
		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_cleanup(void *__ctx)
{
	struct pwm_fan_ctx *ctx = __ctx;

	del_timer_sync(&ctx->rpm_timer);
	/* Switch off everything */
	ctx->enable_mode = pwm_disable_reg_disable;
	pwm_fan_power_off(ctx);
}

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->dev = &pdev->dev;
	ctx->pwm = devm_pwm_get(dev, NULL);
	if (IS_ERR(ctx->pwm))
		return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");

	platform_set_drvdata(pdev, ctx);

	ctx->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;
	}

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

	/*
	 * PWM fans are controlled solely by the duty cycle of the PWM signal,
	 * they do not care about the exact timing. Thus set usage_power to true
	 * to allow less flexible hardware to work as a PWM source for fan
	 * control.
	 */
	ctx->pwm_state.usage_power = true;

	/*
	 * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
	 * long. Check this here to prevent the fan running at a too low
	 * frequency.
	 */
	if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
		dev_err(dev, "Configured period too big\n");
		return -EINVAL;
	}

	ctx->enable_mode = pwm_disable_reg_enable;

	/*
	 * Set duty cycle to maximum allowed and enable PWM output as well as
	 * the regulator. In case of error nothing is changed
	 */
	ret = set_pwm(ctx, 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_cleanup, 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 | HWMON_PWM_ENABLE);

	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 void pwm_fan_shutdown(struct platform_device *pdev)
{
	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);

	pwm_fan_cleanup(ctx);
}

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

	return pwm_fan_power_off(ctx);
}

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

	return set_pwm(ctx, ctx->pwm_value);
}

static DEFINE_SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);

static const struct of_device_id of_pwm_fan_match[] = {
	{ .compatible = "pwm-fan", },
	{},
};
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		= pm_sleep_ptr(&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
b99152d4 AS	31	enum pwm_fan_enable_mode {
	32	pwm_off_reg_off,
	33	pwm_disable_reg_enable,
	34	pwm_enable_reg_enable,
	35	pwm_disable_reg_disable,
	36	};
	37
d82d5776	38	struct pwm_fan_ctx {
b77f0c76 AS	39	struct device *dev;
b77f0c76 AS	40
d82d5776 KD	41	struct mutex lock;
d82d5776 KD	42	struct pwm_device *pwm;
86585c61	43	struct pwm_state pwm_state;
b57e1d42	44	struct regulator *reg_en;
b99152d4	45	enum pwm_fan_enable_mode enable_mode;
9bf3aa60	46	bool regulator_enabled;
b77f0c76	47	bool enabled;
6b1ec478	48
f0dc7cb6 PB	49	int tach_count;
f0dc7cb6 PB	50	struct pwm_fan_tach *tachs;
6b1ec478 SW	51	ktime_t sample_start;
	52	struct timer_list rpm_timer;
	53
2e5219c7 LM	54	unsigned int pwm_value;
	55	unsigned int pwm_fan_state;
	56	unsigned int pwm_fan_max_state;
	57	unsigned int *pwm_fan_cooling_levels;
b6bddec0	58	struct thermal_cooling_device *cdev;
1aa03655 PB	59
1aa03655 PB	60	struct hwmon_chip_info info;
f0dc7cb6	61	struct hwmon_channel_info fan_channel;
1aa03655 PB	62	};
1aa03655 PB	63
6b1ec478 SW	64	/* This handler assumes self resetting edge triggered interrupt. */
	65	static irqreturn_t pulse_handler(int irq, void *dev_id)
	66	{
01695410	67	struct pwm_fan_tach *tach = dev_id;
6b1ec478	68
01695410	69	atomic_inc(&tach->pulses);
6b1ec478 SW	70
	71	return IRQ_HANDLED;
	72	}
	73
	74	static void sample_timer(struct timer_list *t)
	75	{
	76	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
fd8feec6	77	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
f0dc7cb6	78	int i;
6b1ec478	79
fd8feec6	80	if (delta) {
f0dc7cb6 PB	81	for (i = 0; i < ctx->tach_count; i++) {
	82	struct pwm_fan_tach *tach = &ctx->tachs[i];
	83	int pulses;
	84
	85	pulses = atomic_read(&tach->pulses);
	86	atomic_sub(pulses, &tach->pulses);
	87	tach->rpm = (unsigned int)(pulses * 1000 * 60) /
	88	(tach->pulses_per_revolution * delta);
	89	}
fd8feec6 PB	90
	91	ctx->sample_start = ktime_get();
	92	}
6b1ec478	93
6b1ec478 SW	94	mod_timer(&ctx->rpm_timer, jiffies + HZ);
	95	}
	96
b99152d4 AS	97	static void pwm_fan_enable_mode_2_state(int enable_mode,
	98	struct pwm_state *state,
	99	bool *enable_regulator)
	100	{
	101	switch (enable_mode) {
	102	case pwm_disable_reg_enable:
	103	/* disable pwm, keep regulator enabled */
	104	state->enabled = false;
	105	*enable_regulator = true;
	106	break;
	107	case pwm_enable_reg_enable:
	108	/* keep pwm and regulator enabled */
	109	state->enabled = true;
	110	*enable_regulator = true;
	111	break;
	112	case pwm_off_reg_off:
	113	case pwm_disable_reg_disable:
	114	/* disable pwm and regulator */
	115	state->enabled = false;
	116	*enable_regulator = false;
	117	}
	118	}
	119
9bf3aa60 AS	120	static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
	121	{
	122	int ret = 0;
	123
	124	if (!ctx->reg_en)
	125	return ret;
	126
	127	if (!ctx->regulator_enabled && on) {
	128	ret = regulator_enable(ctx->reg_en);
	129	if (ret == 0)
	130	ctx->regulator_enabled = true;
	131	} else if (ctx->regulator_enabled && !on) {
	132	ret = regulator_disable(ctx->reg_en);
	133	if (ret == 0)
	134	ctx->regulator_enabled = false;
	135	}
	136	return ret;
	137	}
	138
bf10ccad	139	static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
d82d5776	140	{
bf10ccad	141	struct pwm_state *state = &ctx->pwm_state;
bf10ccad AS	142	int ret;
bf10ccad AS	143
b77f0c76 AS	144	if (ctx->enabled)
	145	return 0;
	146
b99152d4 AS	147	ret = pwm_fan_switch_power(ctx, true);
	148	if (ret < 0) {
	149	dev_err(ctx->dev, "failed to enable power supply\n");
	150	return ret;
	151	}
	152
bf10ccad AS	153	state->enabled = true;
bf10ccad AS	154	ret = pwm_apply_state(ctx->pwm, state);
b77f0c76 AS	155	if (ret) {
b77f0c76 AS	156	dev_err(ctx->dev, "failed to enable PWM\n");
b99152d4	157	goto disable_regulator;
b77f0c76 AS	158	}
	159
	160	ctx->enabled = true;
bf10ccad	161
b99152d4 AS	162	return 0;
	163
	164	disable_regulator:
	165	pwm_fan_switch_power(ctx, false);
bf10ccad AS	166	return ret;
	167	}
	168
	169	static int pwm_fan_power_off(struct pwm_fan_ctx *ctx)
	170	{
86585c61	171	struct pwm_state *state = &ctx->pwm_state;
b99152d4	172	bool enable_regulator = false;
b77f0c76 AS	173	int ret;
	174
	175	if (!ctx->enabled)
	176	return 0;
2289711c	177
b99152d4 AS	178	pwm_fan_enable_mode_2_state(ctx->enable_mode,
	179	state,
	180	&enable_regulator);
	181
bf10ccad AS	182	state->enabled = false;
bf10ccad AS	183	state->duty_cycle = 0;
b77f0c76 AS	184	ret = pwm_apply_state(ctx->pwm, state);
	185	if (ret) {
	186	dev_err(ctx->dev, "failed to disable PWM\n");
	187	return ret;
	188	}
	189
b99152d4 AS	190	pwm_fan_switch_power(ctx, enable_regulator);
b99152d4 AS	191
b77f0c76	192	ctx->enabled = false;
bf10ccad AS	193
	194	return 0;
	195	}
	196
	197	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
	198	{
b77f0c76 AS	199	struct pwm_state *state = &ctx->pwm_state;
b77f0c76 AS	200	unsigned long period;
bf10ccad AS	201	int ret = 0;
bf10ccad AS	202
b77f0c76	203	if (pwm > 0) {
b99152d4 AS	204	if (ctx->enable_mode == pwm_off_reg_off)
	205	/* pwm-fan hard disabled */
	206	return 0;
	207
b77f0c76 AS	208	period = state->period;
	209	state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	210	ret = pwm_apply_state(ctx->pwm, state);
	211	if (ret)
9db6e7f5	212	return ret;
bf10ccad	213	ret = pwm_fan_power_on(ctx);
b77f0c76	214	} else {
bf10ccad	215	ret = pwm_fan_power_off(ctx);
b77f0c76	216	}
677252a1 BZ	217	if (!ret)
677252a1 BZ	218	ctx->pwm_value = pwm;
bf10ccad	219
9db6e7f5 AS	220	return ret;
	221	}
	222
	223	static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
	224	{
	225	int ret;
	226
	227	mutex_lock(&ctx->lock);
	228	ret = __set_pwm(ctx, pwm);
d82d5776	229	mutex_unlock(&ctx->lock);
9db6e7f5	230
d82d5776 KD	231	return ret;
	232	}
	233
b6bddec0 LM	234	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	235	{
	236	int i;
	237
	238	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	239	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	240	break;
	241
	242	ctx->pwm_fan_state = i;
	243	}
	244
b99152d4 AS	245	static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val)
	246	{
	247	int ret = 0;
	248	int old_val;
	249
	250	mutex_lock(&ctx->lock);
	251
	252	if (ctx->enable_mode == val)
	253	goto out;
	254
	255	old_val = ctx->enable_mode;
	256	ctx->enable_mode = val;
	257
	258	if (val == 0) {
	259	/* Disable pwm-fan unconditionally */
3008d20f MS	260	if (ctx->enabled)
	261	ret = __set_pwm(ctx, 0);
	262	else
	263	ret = pwm_fan_switch_power(ctx, false);
b99152d4 AS	264	if (ret)
	265	ctx->enable_mode = old_val;
	266	pwm_fan_update_state(ctx, 0);
	267	} else {
	268	/*
	269	* Change PWM and/or regulator state if currently disabled
	270	* Nothing to do if currently enabled
	271	*/
	272	if (!ctx->enabled) {
	273	struct pwm_state *state = &ctx->pwm_state;
	274	bool enable_regulator = false;
	275
	276	state->duty_cycle = 0;
	277	pwm_fan_enable_mode_2_state(val,
	278	state,
	279	&enable_regulator);
	280
	281	pwm_apply_state(ctx->pwm, state);
	282	pwm_fan_switch_power(ctx, enable_regulator);
	283	pwm_fan_update_state(ctx, 0);
	284	}
	285	}
	286	out:
	287	mutex_unlock(&ctx->lock);
	288
	289	return ret;
	290	}
	291
1aa03655 PB	292	static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	293	u32 attr, int channel, long val)
cb85ca33 LM	294	{
cb85ca33 LM	295	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
cb85ca33 LM	296	int ret;
cb85ca33 LM	297
b99152d4 AS	298	switch (attr) {
	299	case hwmon_pwm_input:
	300	if (val < 0 \|\| val > MAX_PWM)
	301	return -EINVAL;
	302	ret = set_pwm(ctx, val);
	303	if (ret)
	304	return ret;
	305	pwm_fan_update_state(ctx, val);
	306	break;
	307	case hwmon_pwm_enable:
	308	if (val < 0 \|\| val > 3)
	309	ret = -EINVAL;
	310	else
	311	ret = pwm_fan_update_enable(ctx, val);
cb85ca33	312
cb85ca33	313	return ret;
b99152d4 AS	314	default:
	315	return -EOPNOTSUPP;
	316	}
cb85ca33	317
1aa03655	318	return 0;
cb85ca33 LM	319	}
cb85ca33 LM	320
1aa03655 PB	321	static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
1aa03655 PB	322	u32 attr, int channel, long *val)
d82d5776 KD	323	{
	324	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	325
1aa03655 PB	326	switch (type) {
1aa03655 PB	327	case hwmon_pwm:
b99152d4 AS	328	switch (attr) {
	329	case hwmon_pwm_input:
	330	*val = ctx->pwm_value;
	331	return 0;
	332	case hwmon_pwm_enable:
	333	*val = ctx->enable_mode;
	334	return 0;
	335	}
	336	return -EOPNOTSUPP;
1aa03655	337	case hwmon_fan:
f0dc7cb6	338	*val = ctx->tachs[channel].rpm;
1aa03655	339	return 0;
6b1ec478	340
1aa03655 PB	341	default:
	342	return -ENOTSUPP;
	343	}
6b1ec478	344	}
d82d5776	345
1aa03655 PB	346	static umode_t pwm_fan_is_visible(const void *data,
	347	enum hwmon_sensor_types type,
	348	u32 attr, int channel)
6b1ec478	349	{
1aa03655 PB	350	switch (type) {
	351	case hwmon_pwm:
	352	return 0644;
6b1ec478	353
1aa03655 PB	354	case hwmon_fan:
1aa03655 PB	355	return 0444;
6b1ec478	356
1aa03655 PB	357	default:
	358	return 0;
	359	}
6b1ec478 SW	360	}
6b1ec478 SW	361
1aa03655 PB	362	static const struct hwmon_ops pwm_fan_hwmon_ops = {
	363	.is_visible = pwm_fan_is_visible,
	364	.read = pwm_fan_read,
	365	.write = pwm_fan_write,
6b1ec478	366	};
d82d5776	367
b6bddec0 LM	368	/* thermal cooling device callbacks */
	369	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	370	unsigned long *state)
	371	{
	372	struct pwm_fan_ctx *ctx = cdev->devdata;
	373
	374	if (!ctx)
	375	return -EINVAL;
	376
	377	*state = ctx->pwm_fan_max_state;
	378
	379	return 0;
	380	}
	381
	382	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	383	unsigned long *state)
	384	{
	385	struct pwm_fan_ctx *ctx = cdev->devdata;
	386
	387	if (!ctx)
	388	return -EINVAL;
	389
	390	*state = ctx->pwm_fan_state;
	391
	392	return 0;
	393	}
	394
	395	static int
	396	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	397	{
	398	struct pwm_fan_ctx *ctx = cdev->devdata;
	399	int ret;
	400
	401	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	402	return -EINVAL;
	403
	404	if (state == ctx->pwm_fan_state)
	405	return 0;
	406
9db6e7f5	407	ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
b6bddec0 LM	408	if (ret) {
	409	dev_err(&cdev->device, "Cannot set pwm!\n");
	410	return ret;
	411	}
	412
	413	ctx->pwm_fan_state = state;
	414
	415	return ret;
	416	}
	417
	418	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	419	.get_max_state = pwm_fan_get_max_state,
	420	.get_cur_state = pwm_fan_get_cur_state,
	421	.set_cur_state = pwm_fan_set_cur_state,
	422	};
	423
de52b049 GR	424	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	425	struct pwm_fan_ctx *ctx)
2e5219c7 LM	426	{
	427	struct device_node *np = dev->of_node;
	428	int num, i, ret;
	429
914b2fd2	430	if (!of_property_present(np, "cooling-levels"))
2e5219c7 LM	431	return 0;
	432
	433	ret = of_property_count_u32_elems(np, "cooling-levels");
	434	if (ret <= 0) {
	435	dev_err(dev, "Wrong data!\n");
	436	return ret ? : -EINVAL;
	437	}
	438
	439	num = ret;
a86854d0	440	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
2e5219c7 LM	441	GFP_KERNEL);
	442	if (!ctx->pwm_fan_cooling_levels)
	443	return -ENOMEM;
	444
	445	ret = of_property_read_u32_array(np, "cooling-levels",
	446	ctx->pwm_fan_cooling_levels, num);
	447	if (ret) {
	448	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	449	return ret;
	450	}
	451
	452	for (i = 0; i < num; i++) {
	453	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	454	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	455	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	456	return -EINVAL;
	457	}
	458	}
	459
	460	ctx->pwm_fan_max_state = num - 1;
	461
	462	return 0;
	463	}
	464
b99152d4	465	static void pwm_fan_cleanup(void *__ctx)
37bcec5d	466	{
a455eda3	467	struct pwm_fan_ctx *ctx = __ctx;
86585c61	468
a455eda3	469	del_timer_sync(&ctx->rpm_timer);
b99152d4 AS	470	/* Switch off everything */
	471	ctx->enable_mode = pwm_disable_reg_disable;
	472	pwm_fan_power_off(ctx);
37bcec5d GR	473	}
37bcec5d GR	474
d82d5776 KD	475	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	476	{
b6bddec0	477	struct thermal_cooling_device *cdev;
37bcec5d	478	struct device *dev = &pdev->dev;
d82d5776	479	struct pwm_fan_ctx *ctx;
b6bddec0	480	struct device *hwmon;
d82d5776	481	int ret;
1aa03655	482	const struct hwmon_channel_info **channels;
f0dc7cb6 PB	483	u32 *fan_channel_config;
	484	int channel_count = 1; /* We always have a PWM channel. */
	485	int i;
d82d5776	486
37bcec5d	487	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
d82d5776 KD	488	if (!ctx)
	489	return -ENOMEM;
	490
	491	mutex_init(&ctx->lock);
	492
b77f0c76	493	ctx->dev = &pdev->dev;
2e2aa25c	494	ctx->pwm = devm_pwm_get(dev, NULL);
65b2aad0 AH	495	if (IS_ERR(ctx->pwm))
65b2aad0 AH	496	return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
d82d5776	497
d82d5776 KD	498	platform_set_drvdata(pdev, ctx);
d82d5776 KD	499
37bcec5d	500	ctx->reg_en = devm_regulator_get_optional(dev, "fan");
b57e1d42 SW	501	if (IS_ERR(ctx->reg_en)) {
	502	if (PTR_ERR(ctx->reg_en) != -ENODEV)
	503	return PTR_ERR(ctx->reg_en);
	504
	505	ctx->reg_en = NULL;
b57e1d42 SW	506	}
b57e1d42 SW	507
86585c61 UKK	508	pwm_init_state(ctx->pwm, &ctx->pwm_state);
86585c61 UKK	509
a7da8a8b LB	510	/*
	511	* PWM fans are controlled solely by the duty cycle of the PWM signal,
	512	* they do not care about the exact timing. Thus set usage_power to true
	513	* to allow less flexible hardware to work as a PWM source for fan
	514	* control.
	515	*/
	516	ctx->pwm_state.usage_power = true;
	517
1eda5233	518	/*
9db6e7f5	519	* set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
1eda5233 UKK	520	* long. Check this here to prevent the fan running at a too low
	521	* frequency.
	522	*/
86585c61	523	if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
1eda5233 UKK	524	dev_err(dev, "Configured period too big\n");
	525	return -EINVAL;
	526	}
	527
b99152d4 AS	528	ctx->enable_mode = pwm_disable_reg_enable;
	529
	530	/*
	531	* Set duty cycle to maximum allowed and enable PWM output as well as
	532	* the regulator. In case of error nothing is changed
	533	*/
9db6e7f5	534	ret = set_pwm(ctx, MAX_PWM);
d82d5776	535	if (ret) {
a455eda3	536	dev_err(dev, "Failed to configure PWM: %d\n", ret);
37bcec5d	537	return ret;
d82d5776	538	}
6b1ec478	539	timer_setup(&ctx->rpm_timer, sample_timer, 0);
b99152d4	540	ret = devm_add_action_or_reset(dev, pwm_fan_cleanup, ctx);
5696e4aa GR	541	if (ret)
5696e4aa GR	542	return ret;
6b1ec478	543
f0dc7cb6 PB	544	ctx->tach_count = platform_irq_count(pdev);
	545	if (ctx->tach_count < 0)
	546	return dev_err_probe(dev, ctx->tach_count,
b5fcb8a4	547	"Could not get number of fan tachometer inputs\n");
f0dc7cb6	548	dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
b5fcb8a4	549
f0dc7cb6 PB	550	if (ctx->tach_count) {
	551	channel_count++; /* We also have a FAN channel. */
	552
	553	ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
	554	sizeof(struct pwm_fan_tach),
	555	GFP_KERNEL);
	556	if (!ctx->tachs)
	557	return -ENOMEM;
	558
	559	ctx->fan_channel.type = hwmon_fan;
	560	fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
	561	sizeof(u32), GFP_KERNEL);
	562	if (!fan_channel_config)
	563	return -ENOMEM;
	564	ctx->fan_channel.config = fan_channel_config;
	565	}
	566
	567	channels = devm_kcalloc(dev, channel_count + 1,
1aa03655 PB	568	sizeof(struct hwmon_channel_info *), GFP_KERNEL);
	569	if (!channels)
	570	return -ENOMEM;
	571
b99152d4	572	channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT \| HWMON_PWM_ENABLE);
1aa03655	573
f0dc7cb6 PB	574	for (i = 0; i < ctx->tach_count; i++) {
f0dc7cb6 PB	575	struct pwm_fan_tach *tach = &ctx->tachs[i];
b5fcb8a4 PB	576	u32 ppr = 2;
b5fcb8a4 PB	577
f0dc7cb6	578	tach->irq = platform_get_irq(pdev, i);
01695410 PB	579	if (tach->irq == -EPROBE_DEFER)
	580	return tach->irq;
	581	if (tach->irq > 0) {
	582	ret = devm_request_irq(dev, tach->irq, pulse_handler, 0,
	583	pdev->name, tach);
b5fcb8a4 PB	584	if (ret) {
	585	dev_err(dev,
	586	"Failed to request interrupt: %d\n",
	587	ret);
	588	return ret;
	589	}
	590	}
6b1ec478	591
f0dc7cb6 PB	592	of_property_read_u32_index(dev->of_node,
	593	"pulses-per-revolution",
	594	i,
	595	&ppr);
01695410 PB	596	tach->pulses_per_revolution = ppr;
01695410 PB	597	if (!tach->pulses_per_revolution) {
b5fcb8a4 PB	598	dev_err(dev, "pulses-per-revolution can't be zero.\n");
b5fcb8a4 PB	599	return -EINVAL;
6b1ec478	600	}
b5fcb8a4	601
f0dc7cb6 PB	602	fan_channel_config[i] = HWMON_F_INPUT;
	603
	604	dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
	605	i, tach->irq, tach->pulses_per_revolution);
	606	}
b5fcb8a4	607
f0dc7cb6	608	if (ctx->tach_count > 0) {
6b1ec478 SW	609	ctx->sample_start = ktime_get();
6b1ec478 SW	610	mod_timer(&ctx->rpm_timer, jiffies + HZ);
1aa03655	611
f0dc7cb6	612	channels[1] = &ctx->fan_channel;
6b1ec478 SW	613	}
6b1ec478 SW	614
1aa03655 PB	615	ctx->info.ops = &pwm_fan_hwmon_ops;
	616	ctx->info.info = channels;
	617
	618	hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
	619	ctx, &ctx->info, NULL);
d82d5776	620	if (IS_ERR(hwmon)) {
37bcec5d GR	621	dev_err(dev, "Failed to register hwmon device\n");
37bcec5d GR	622	return PTR_ERR(hwmon);
d82d5776	623	}
2e5219c7	624
37bcec5d	625	ret = pwm_fan_of_get_cooling_data(dev, ctx);
2e5219c7 LM	626	if (ret)
	627	return ret;
	628
b6bddec0 LM	629	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
b6bddec0 LM	630	if (IS_ENABLED(CONFIG_THERMAL)) {
37bcec5d GR	631	cdev = devm_thermal_of_cooling_device_register(dev,
37bcec5d GR	632	dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
b6bddec0	633	if (IS_ERR(cdev)) {
677252a1	634	ret = PTR_ERR(cdev);
37bcec5d	635	dev_err(dev,
841cf676 RM	636	"Failed to register pwm-fan as cooling device: %d\n",
841cf676 RM	637	ret);
a455eda3	638	return ret;
b6bddec0 LM	639	}
b6bddec0 LM	640	ctx->cdev = cdev;
b6bddec0 LM	641	}
b6bddec0 LM	642
d82d5776	643	return 0;
d82d5776 KD	644	}
d82d5776 KD	645
7992db7c AM	646	static void pwm_fan_shutdown(struct platform_device *pdev)
7992db7c AM	647	{
b99152d4 AS	648	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
	649
	650	pwm_fan_cleanup(ctx);
7992db7c AM	651	}
7992db7c AM	652
7992db7c AM	653	static int pwm_fan_suspend(struct device *dev)
7992db7c AM	654	{
b99152d4 AS	655	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	656
	657	return pwm_fan_power_off(ctx);
7992db7c AM	658	}
7992db7c AM	659
d82d5776 KD	660	static int pwm_fan_resume(struct device *dev)
	661	{
	662	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
48b9d5b4	663
b99152d4	664	return set_pwm(ctx, ctx->pwm_value);
d82d5776	665	}
d82d5776	666
1839391b	667	static DEFINE_SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
d82d5776	668
d720acac	669	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	670	{ .compatible = "pwm-fan", },
	671	{},
	672	};
f491e70c	673	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	674
	675	static struct platform_driver pwm_fan_driver = {
	676	.probe = pwm_fan_probe,
7992db7c	677	.shutdown = pwm_fan_shutdown,
d82d5776 KD	678	.driver = {
d82d5776 KD	679	.name = "pwm-fan",
1839391b	680	.pm = pm_sleep_ptr(&pwm_fan_pm),
d82d5776 KD	681	.of_match_table = of_pwm_fan_match,
	682	},
	683	};
	684
	685	module_platform_driver(pwm_fan_driver);
	686
	687	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	688	MODULE_ALIAS("platform:pwm-fan");
	689	MODULE_DESCRIPTION("PWM FAN driver");
	690	MODULE_LICENSE("GPL");