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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
 *
 * Copyright (C) 2010 LaCie
 *
 * Author: Simon Guinot <sguinot@lacie.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/kstrtox.h>
#include <linux/mutex.h>
#include <linux/hwmon.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/thermal.h>

struct gpio_fan_speed {
	int rpm;
	int ctrl_val;
};

struct gpio_fan_data {
	struct device		*dev;
	struct device		*hwmon_dev;
	/* Cooling device if any */
	struct thermal_cooling_device *cdev;
	struct mutex		lock; /* lock GPIOs operations. */
	int			num_gpios;
	struct gpio_desc	**gpios;
	int			num_speed;
	struct gpio_fan_speed	*speed;
	int			speed_index;
	int			resume_speed;
	bool			pwm_enable;
	struct gpio_desc	*alarm_gpio;
	struct work_struct	alarm_work;
};

/*
 * Alarm GPIO.
 */

static void fan_alarm_notify(struct work_struct *ws)
{
	struct gpio_fan_data *fan_data =
		container_of(ws, struct gpio_fan_data, alarm_work);

	sysfs_notify(&fan_data->hwmon_dev->kobj, NULL, "fan1_alarm");
	kobject_uevent(&fan_data->hwmon_dev->kobj, KOBJ_CHANGE);
}

static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
{
	struct gpio_fan_data *fan_data = dev_id;

	schedule_work(&fan_data->alarm_work);

	return IRQ_NONE;
}

static ssize_t fan1_alarm_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n",
		       gpiod_get_value_cansleep(fan_data->alarm_gpio));
}

static DEVICE_ATTR_RO(fan1_alarm);

static int fan_alarm_init(struct gpio_fan_data *fan_data)
{
	int alarm_irq;
	struct device *dev = fan_data->dev;

	/*
	 * If the alarm GPIO don't support interrupts, just leave
	 * without initializing the fail notification support.
	 */
	alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
	if (alarm_irq <= 0)
		return 0;

	INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
	irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
	return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
				IRQF_SHARED, "GPIO fan alarm", fan_data);
}

/*
 * Control GPIOs.
 */

/* Must be called with fan_data->lock held, except during initialization. */
static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
{
	int i;

	for (i = 0; i < fan_data->num_gpios; i++)
		gpiod_set_value_cansleep(fan_data->gpios[i],
					 (ctrl_val >> i) & 1);
}

static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
{
	int i;
	int ctrl_val = 0;

	for (i = 0; i < fan_data->num_gpios; i++) {
		int value;

		value = gpiod_get_value_cansleep(fan_data->gpios[i]);
		ctrl_val |= (value << i);
	}
	return ctrl_val;
}

/* Must be called with fan_data->lock held, except during initialization. */
static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
{
	if (fan_data->speed_index == speed_index)
		return;

	__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
	fan_data->speed_index = speed_index;
}

static int get_fan_speed_index(struct gpio_fan_data *fan_data)
{
	int ctrl_val = __get_fan_ctrl(fan_data);
	int i;

	for (i = 0; i < fan_data->num_speed; i++)
		if (fan_data->speed[i].ctrl_val == ctrl_val)
			return i;

	dev_warn(fan_data->dev,
		 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);

	return -ENODEV;
}

static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
{
	struct gpio_fan_speed *speed = fan_data->speed;
	int i;

	for (i = 0; i < fan_data->num_speed; i++)
		if (speed[i].rpm >= rpm)
			return i;

	return fan_data->num_speed - 1;
}

static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);

	return sprintf(buf, "%d\n", pwm);
}

static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	unsigned long pwm;
	int speed_index;
	int ret = count;

	if (kstrtoul(buf, 10, &pwm) || pwm > 255)
		return -EINVAL;

	mutex_lock(&fan_data->lock);

	if (!fan_data->pwm_enable) {
		ret = -EPERM;
		goto exit_unlock;
	}

	speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
	set_fan_speed(fan_data, speed_index);

exit_unlock:
	mutex_unlock(&fan_data->lock);

	return ret;
}

static ssize_t pwm1_enable_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", fan_data->pwm_enable);
}

static ssize_t pwm1_enable_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	unsigned long val;

	if (kstrtoul(buf, 10, &val) || val > 1)
		return -EINVAL;

	if (fan_data->pwm_enable == val)
		return count;

	mutex_lock(&fan_data->lock);

	fan_data->pwm_enable = val;

	/* Disable manual control mode: set fan at full speed. */
	if (val == 0)
		set_fan_speed(fan_data, fan_data->num_speed - 1);

	mutex_unlock(&fan_data->lock);

	return count;
}

static ssize_t pwm1_mode_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "0\n");
}

static ssize_t fan1_min_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
}

static ssize_t fan1_max_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n",
		       fan_data->speed[fan_data->num_speed - 1].rpm);
}

static ssize_t fan1_input_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
}

static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
		       const char *buf, size_t count)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	unsigned long rpm;
	int ret = count;

	if (kstrtoul(buf, 10, &rpm))
		return -EINVAL;

	mutex_lock(&fan_data->lock);

	if (!fan_data->pwm_enable) {
		ret = -EPERM;
		goto exit_unlock;
	}

	set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));

exit_unlock:
	mutex_unlock(&fan_data->lock);

	return ret;
}

static DEVICE_ATTR_RW(pwm1);
static DEVICE_ATTR_RW(pwm1_enable);
static DEVICE_ATTR_RO(pwm1_mode);
static DEVICE_ATTR_RO(fan1_min);
static DEVICE_ATTR_RO(fan1_max);
static DEVICE_ATTR_RO(fan1_input);
static DEVICE_ATTR(fan1_target, 0644, fan1_input_show, set_rpm);

static umode_t gpio_fan_is_visible(struct kobject *kobj,
				   struct attribute *attr, int index)
{
	struct device *dev = kobj_to_dev(kobj);
	struct gpio_fan_data *data = dev_get_drvdata(dev);

	if (index == 0 && !data->alarm_gpio)
		return 0;
	if (index > 0 && !data->gpios)
		return 0;

	return attr->mode;
}

static struct attribute *gpio_fan_attributes[] = {
	&dev_attr_fan1_alarm.attr,		/* 0 */
	&dev_attr_pwm1.attr,			/* 1 */
	&dev_attr_pwm1_enable.attr,
	&dev_attr_pwm1_mode.attr,
	&dev_attr_fan1_input.attr,
	&dev_attr_fan1_target.attr,
	&dev_attr_fan1_min.attr,
	&dev_attr_fan1_max.attr,
	NULL
};

static const struct attribute_group gpio_fan_group = {
	.attrs = gpio_fan_attributes,
	.is_visible = gpio_fan_is_visible,
};

static const struct attribute_group *gpio_fan_groups[] = {
	&gpio_fan_group,
	NULL
};

static int fan_ctrl_init(struct gpio_fan_data *fan_data)
{
	int num_gpios = fan_data->num_gpios;
	struct gpio_desc **gpios = fan_data->gpios;
	int i, err;

	for (i = 0; i < num_gpios; i++) {
		/*
		 * The GPIO descriptors were retrieved with GPIOD_ASIS so here
		 * we set the GPIO into output mode, carefully preserving the
		 * current value by setting it to whatever it is already set
		 * (no surprise changes in default fan speed).
		 */
		err = gpiod_direction_output(gpios[i],
					gpiod_get_value_cansleep(gpios[i]));
		if (err)
			return err;
	}

	fan_data->pwm_enable = true; /* Enable manual fan speed control. */
	fan_data->speed_index = get_fan_speed_index(fan_data);
	if (fan_data->speed_index < 0)
		return fan_data->speed_index;

	return 0;
}

static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
				  unsigned long *state)
{
	struct gpio_fan_data *fan_data = cdev->devdata;

	if (!fan_data)
		return -EINVAL;

	*state = fan_data->num_speed - 1;
	return 0;
}

static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
				  unsigned long *state)
{
	struct gpio_fan_data *fan_data = cdev->devdata;

	if (!fan_data)
		return -EINVAL;

	*state = fan_data->speed_index;
	return 0;
}

static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
				  unsigned long state)
{
	struct gpio_fan_data *fan_data = cdev->devdata;

	if (!fan_data)
		return -EINVAL;

	if (state >= fan_data->num_speed)
		return -EINVAL;

	set_fan_speed(fan_data, state);
	return 0;
}

static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
	.get_max_state = gpio_fan_get_max_state,
	.get_cur_state = gpio_fan_get_cur_state,
	.set_cur_state = gpio_fan_set_cur_state,
};

/*
 * Translate OpenFirmware node properties into platform_data
 */
static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
{
	struct gpio_fan_speed *speed;
	struct device *dev = fan_data->dev;
	struct device_node *np = dev->of_node;
	struct gpio_desc **gpios;
	unsigned i;
	u32 u;
	struct property *prop;
	const __be32 *p;

	/* Alarm GPIO if one exists */
	fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
	if (IS_ERR(fan_data->alarm_gpio))
		return PTR_ERR(fan_data->alarm_gpio);

	/* Fill GPIO pin array */
	fan_data->num_gpios = gpiod_count(dev, NULL);
	if (fan_data->num_gpios <= 0) {
		if (fan_data->alarm_gpio)
			return 0;
		dev_err(dev, "DT properties empty / missing");
		return -ENODEV;
	}
	gpios = devm_kcalloc(dev,
			     fan_data->num_gpios, sizeof(struct gpio_desc *),
			     GFP_KERNEL);
	if (!gpios)
		return -ENOMEM;
	for (i = 0; i < fan_data->num_gpios; i++) {
		gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
		if (IS_ERR(gpios[i]))
			return PTR_ERR(gpios[i]);
	}
	fan_data->gpios = gpios;

	/* Get number of RPM/ctrl_val pairs in speed map */
	prop = of_find_property(np, "gpio-fan,speed-map", &i);
	if (!prop) {
		dev_err(dev, "gpio-fan,speed-map DT property missing");
		return -ENODEV;
	}
	i = i / sizeof(u32);
	if (i == 0 || i & 1) {
		dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
		return -ENODEV;
	}
	fan_data->num_speed = i / 2;

	/*
	 * Populate speed map
	 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
	 * this needs splitting into pairs to create gpio_fan_speed structs
	 */
	speed = devm_kcalloc(dev,
			fan_data->num_speed, sizeof(struct gpio_fan_speed),
			GFP_KERNEL);
	if (!speed)
		return -ENOMEM;
	p = NULL;
	for (i = 0; i < fan_data->num_speed; i++) {
		p = of_prop_next_u32(prop, p, &u);
		if (!p)
			return -ENODEV;
		speed[i].rpm = u;
		p = of_prop_next_u32(prop, p, &u);
		if (!p)
			return -ENODEV;
		speed[i].ctrl_val = u;
	}
	fan_data->speed = speed;

	return 0;
}

static const struct of_device_id of_gpio_fan_match[] = {
	{ .compatible = "gpio-fan", },
	{},
};
MODULE_DEVICE_TABLE(of, of_gpio_fan_match);

static void gpio_fan_stop(void *data)
{
	set_fan_speed(data, 0);
}

static int gpio_fan_probe(struct platform_device *pdev)
{
	int err;
	struct gpio_fan_data *fan_data;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;

	fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
				GFP_KERNEL);
	if (!fan_data)
		return -ENOMEM;

	fan_data->dev = dev;
	err = gpio_fan_get_of_data(fan_data);
	if (err)
		return err;

	platform_set_drvdata(pdev, fan_data);
	mutex_init(&fan_data->lock);

	/* Configure control GPIOs if available. */
	if (fan_data->gpios && fan_data->num_gpios > 0) {
		if (!fan_data->speed || fan_data->num_speed <= 1)
			return -EINVAL;
		err = fan_ctrl_init(fan_data);
		if (err)
			return err;
		err = devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
		if (err)
			return err;
	}

	/* Make this driver part of hwmon class. */
	fan_data->hwmon_dev =
		devm_hwmon_device_register_with_groups(dev,
						       "gpio_fan", fan_data,
						       gpio_fan_groups);
	if (IS_ERR(fan_data->hwmon_dev))
		return PTR_ERR(fan_data->hwmon_dev);

	/* Configure alarm GPIO if available. */
	if (fan_data->alarm_gpio) {
		err = fan_alarm_init(fan_data);
		if (err)
			return err;
	}

	/* Optional cooling device register for Device tree platforms */
	fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
				"gpio-fan", fan_data, &gpio_fan_cool_ops);

	dev_info(dev, "GPIO fan initialized\n");

	return 0;
}

static void gpio_fan_shutdown(struct platform_device *pdev)
{
	struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);

	if (fan_data->gpios)
		set_fan_speed(fan_data, 0);
}

static int gpio_fan_suspend(struct device *dev)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	if (fan_data->gpios) {
		fan_data->resume_speed = fan_data->speed_index;
		set_fan_speed(fan_data, 0);
	}

	return 0;
}

static int gpio_fan_resume(struct device *dev)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);

	if (fan_data->gpios)
		set_fan_speed(fan_data, fan_data->resume_speed);

	return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);

static struct platform_driver gpio_fan_driver = {
	.probe		= gpio_fan_probe,
	.shutdown	= gpio_fan_shutdown,
	.driver	= {
		.name	= "gpio-fan",
		.pm	= pm_sleep_ptr(&gpio_fan_pm),
		.of_match_table = of_gpio_fan_match,
	},
};

module_platform_driver(gpio_fan_driver);

MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
MODULE_DESCRIPTION("GPIO FAN driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-fan");
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
d6fe1360 SG	2	/*
	3	* gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
	4	*
	5	* Copyright (C) 2010 LaCie
	6	*
	7	* Author: Simon Guinot <sguinot@lacie.com>
d6fe1360 SG	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/init.h>
	12	#include <linux/slab.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/irq.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/err.h>
25f98688	17	#include <linux/kstrtox.h>
d6fe1360 SG	18	#include <linux/mutex.h>
d6fe1360 SG	19	#include <linux/hwmon.h>
9de382fd	20	#include <linux/gpio/consumer.h>
c50588ab	21	#include <linux/of.h>
55fb8b06	22	#include <linux/of_platform.h>
b5cf88e4	23	#include <linux/thermal.h>
d6fe1360	24
ef7a6124 LW	25	struct gpio_fan_speed {
	26	int rpm;
	27	int ctrl_val;
	28	};
	29
d6fe1360	30	struct gpio_fan_data {
8c0eb9bc	31	struct device *dev;
d6fe1360	32	struct device *hwmon_dev;
b5cf88e4 NM	33	/* Cooling device if any */
b5cf88e4 NM	34	struct thermal_cooling_device *cdev;
d6fe1360	35	struct mutex lock; /* lock GPIOs operations. */
e99c2e5d	36	int num_gpios;
9de382fd	37	struct gpio_desc **gpios;
d6fe1360 SG	38	int num_speed;
	39	struct gpio_fan_speed *speed;
	40	int speed_index;
d6fe1360	41	int resume_speed;
d6fe1360	42	bool pwm_enable;
9de382fd	43	struct gpio_desc *alarm_gpio;
d6fe1360 SG	44	struct work_struct alarm_work;
	45	};
	46
	47	/*
	48	* Alarm GPIO.
	49	*/
	50
	51	static void fan_alarm_notify(struct work_struct *ws)
	52	{
	53	struct gpio_fan_data *fan_data =
	54	container_of(ws, struct gpio_fan_data, alarm_work);
	55
277c628f CS	56	sysfs_notify(&fan_data->hwmon_dev->kobj, NULL, "fan1_alarm");
277c628f CS	57	kobject_uevent(&fan_data->hwmon_dev->kobj, KOBJ_CHANGE);
d6fe1360 SG	58	}
	59
	60	static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
	61	{
	62	struct gpio_fan_data *fan_data = dev_id;
	63
	64	schedule_work(&fan_data->alarm_work);
	65
	66	return IRQ_NONE;
	67	}
	68
c490c63e JL	69	static ssize_t fan1_alarm_show(struct device *dev,
c490c63e JL	70	struct device_attribute attr, char buf)
d6fe1360 SG	71	{
d6fe1360 SG	72	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
d6fe1360	73
9de382fd LW	74	return sprintf(buf, "%d\n",
9de382fd LW	75	gpiod_get_value_cansleep(fan_data->alarm_gpio));
d6fe1360 SG	76	}
d6fe1360 SG	77
c490c63e	78	static DEVICE_ATTR_RO(fan1_alarm);
d6fe1360	79
b5482f7e	80	static int fan_alarm_init(struct gpio_fan_data *fan_data)
d6fe1360	81	{
d6fe1360	82	int alarm_irq;
8c0eb9bc	83	struct device *dev = fan_data->dev;
d6fe1360	84
d6fe1360 SG	85	/*
	86	* If the alarm GPIO don't support interrupts, just leave
	87	* without initializing the fail notification support.
	88	*/
9de382fd LW	89	alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
9de382fd LW	90	if (alarm_irq <= 0)
d6fe1360 SG	91	return 0;
	92
	93	INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
dced35ae	94	irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
9de382fd LW	95	return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
9de382fd LW	96	IRQF_SHARED, "GPIO fan alarm", fan_data);
d6fe1360 SG	97	}
d6fe1360 SG	98
d6fe1360 SG	99	/*
	100	* Control GPIOs.
	101	*/
	102
	103	/* Must be called with fan_data->lock held, except during initialization. */
	104	static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
	105	{
	106	int i;
	107
e99c2e5d	108	for (i = 0; i < fan_data->num_gpios; i++)
9de382fd LW	109	gpiod_set_value_cansleep(fan_data->gpios[i],
9de382fd LW	110	(ctrl_val >> i) & 1);
d6fe1360 SG	111	}
	112
	113	static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
	114	{
	115	int i;
	116	int ctrl_val = 0;
	117
e99c2e5d	118	for (i = 0; i < fan_data->num_gpios; i++) {
d6fe1360 SG	119	int value;
d6fe1360 SG	120
9de382fd	121	value = gpiod_get_value_cansleep(fan_data->gpios[i]);
d6fe1360 SG	122	ctrl_val \|= (value << i);
	123	}
	124	return ctrl_val;
	125	}
	126
	127	/* Must be called with fan_data->lock held, except during initialization. */
	128	static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
	129	{
	130	if (fan_data->speed_index == speed_index)
	131	return;
	132
	133	__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
	134	fan_data->speed_index = speed_index;
	135	}
	136
	137	static int get_fan_speed_index(struct gpio_fan_data *fan_data)
	138	{
	139	int ctrl_val = __get_fan_ctrl(fan_data);
	140	int i;
	141
	142	for (i = 0; i < fan_data->num_speed; i++)
	143	if (fan_data->speed[i].ctrl_val == ctrl_val)
	144	return i;
	145
8c0eb9bc	146	dev_warn(fan_data->dev,
d6fe1360 SG	147	"missing speed array entry for GPIO value 0x%x\n", ctrl_val);
d6fe1360 SG	148
c52ae3d2	149	return -ENODEV;
d6fe1360 SG	150	}
d6fe1360 SG	151
2565fb05	152	static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
d6fe1360 SG	153	{
	154	struct gpio_fan_speed *speed = fan_data->speed;
	155	int i;
	156
	157	for (i = 0; i < fan_data->num_speed; i++)
	158	if (speed[i].rpm >= rpm)
	159	return i;
	160
	161	return fan_data->num_speed - 1;
	162	}
	163
c490c63e JL	164	static ssize_t pwm1_show(struct device dev, struct device_attribute attr,
c490c63e JL	165	char *buf)
d6fe1360 SG	166	{
	167	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	168	u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
	169
	170	return sprintf(buf, "%d\n", pwm);
	171	}
	172
c490c63e JL	173	static ssize_t pwm1_store(struct device dev, struct device_attribute attr,
c490c63e JL	174	const char *buf, size_t count)
d6fe1360 SG	175	{
	176	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	177	unsigned long pwm;
	178	int speed_index;
	179	int ret = count;
	180
179c4fdb	181	if (kstrtoul(buf, 10, &pwm) \|\| pwm > 255)
d6fe1360 SG	182	return -EINVAL;
	183
	184	mutex_lock(&fan_data->lock);
	185
	186	if (!fan_data->pwm_enable) {
	187	ret = -EPERM;
	188	goto exit_unlock;
	189	}
	190
	191	speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
	192	set_fan_speed(fan_data, speed_index);
	193
	194	exit_unlock:
	195	mutex_unlock(&fan_data->lock);
	196
	197	return ret;
	198	}
	199
c490c63e JL	200	static ssize_t pwm1_enable_show(struct device *dev,
c490c63e JL	201	struct device_attribute attr, char buf)
d6fe1360 SG	202	{
	203	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	204
	205	return sprintf(buf, "%d\n", fan_data->pwm_enable);
	206	}
	207
c490c63e JL	208	static ssize_t pwm1_enable_store(struct device *dev,
	209	struct device_attribute *attr,
	210	const char *buf, size_t count)
d6fe1360 SG	211	{
	212	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	213	unsigned long val;
	214
179c4fdb	215	if (kstrtoul(buf, 10, &val) \|\| val > 1)
d6fe1360 SG	216	return -EINVAL;
	217
	218	if (fan_data->pwm_enable == val)
	219	return count;
	220
	221	mutex_lock(&fan_data->lock);
	222
	223	fan_data->pwm_enable = val;
	224
	225	/* Disable manual control mode: set fan at full speed. */
	226	if (val == 0)
	227	set_fan_speed(fan_data, fan_data->num_speed - 1);
	228
	229	mutex_unlock(&fan_data->lock);
	230
	231	return count;
	232	}
	233
c490c63e JL	234	static ssize_t pwm1_mode_show(struct device *dev,
c490c63e JL	235	struct device_attribute attr, char buf)
d6fe1360 SG	236	{
	237	return sprintf(buf, "0\n");
	238	}
	239
c490c63e JL	240	static ssize_t fan1_min_show(struct device *dev,
c490c63e JL	241	struct device_attribute attr, char buf)
d6fe1360 SG	242	{
	243	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	244
	245	return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
	246	}
	247
c490c63e JL	248	static ssize_t fan1_max_show(struct device *dev,
c490c63e JL	249	struct device_attribute attr, char buf)
d6fe1360 SG	250	{
	251	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	252
	253	return sprintf(buf, "%d\n",
	254	fan_data->speed[fan_data->num_speed - 1].rpm);
	255	}
	256
c490c63e JL	257	static ssize_t fan1_input_show(struct device *dev,
c490c63e JL	258	struct device_attribute attr, char buf)
d6fe1360 SG	259	{
	260	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	261
	262	return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
	263	}
	264
	265	static ssize_t set_rpm(struct device dev, struct device_attribute attr,
	266	const char *buf, size_t count)
	267	{
	268	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	269	unsigned long rpm;
	270	int ret = count;
	271
179c4fdb	272	if (kstrtoul(buf, 10, &rpm))
d6fe1360 SG	273	return -EINVAL;
	274
	275	mutex_lock(&fan_data->lock);
	276
	277	if (!fan_data->pwm_enable) {
	278	ret = -EPERM;
	279	goto exit_unlock;
	280	}
	281
	282	set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
	283
	284	exit_unlock:
	285	mutex_unlock(&fan_data->lock);
	286
	287	return ret;
	288	}
	289
c490c63e JL	290	static DEVICE_ATTR_RW(pwm1);
	291	static DEVICE_ATTR_RW(pwm1_enable);
	292	static DEVICE_ATTR_RO(pwm1_mode);
	293	static DEVICE_ATTR_RO(fan1_min);
	294	static DEVICE_ATTR_RO(fan1_max);
	295	static DEVICE_ATTR_RO(fan1_input);
905bc0d4	296	static DEVICE_ATTR(fan1_target, 0644, fan1_input_show, set_rpm);
d6fe1360	297
c81cc5a4 GR	298	static umode_t gpio_fan_is_visible(struct kobject *kobj,
	299	struct attribute *attr, int index)
	300	{
8bfc731e	301	struct device *dev = kobj_to_dev(kobj);
c81cc5a4 GR	302	struct gpio_fan_data *data = dev_get_drvdata(dev);
c81cc5a4 GR	303
c9933cb1	304	if (index == 0 && !data->alarm_gpio)
c81cc5a4	305	return 0;
e99c2e5d	306	if (index > 0 && !data->gpios)
c81cc5a4 GR	307	return 0;
	308
	309	return attr->mode;
	310	}
	311
	312	static struct attribute *gpio_fan_attributes[] = {
7258a125 GR	313	&dev_attr_fan1_alarm.attr, /* 0 */
7258a125 GR	314	&dev_attr_pwm1.attr, /* 1 */
d6fe1360 SG	315	&dev_attr_pwm1_enable.attr,
	316	&dev_attr_pwm1_mode.attr,
	317	&dev_attr_fan1_input.attr,
	318	&dev_attr_fan1_target.attr,
	319	&dev_attr_fan1_min.attr,
	320	&dev_attr_fan1_max.attr,
	321	NULL
	322	};
	323
c81cc5a4 GR	324	static const struct attribute_group gpio_fan_group = {
	325	.attrs = gpio_fan_attributes,
	326	.is_visible = gpio_fan_is_visible,
d6fe1360 SG	327	};
d6fe1360 SG	328
7258a125 GR	329	static const struct attribute_group *gpio_fan_groups[] = {
	330	&gpio_fan_group,
	331	NULL
	332	};
	333
b5482f7e	334	static int fan_ctrl_init(struct gpio_fan_data *fan_data)
d6fe1360	335	{
e99c2e5d	336	int num_gpios = fan_data->num_gpios;
9de382fd	337	struct gpio_desc **gpios = fan_data->gpios;
d6fe1360 SG	338	int i, err;
d6fe1360 SG	339
e99c2e5d	340	for (i = 0; i < num_gpios; i++) {
9de382fd LW	341	/*
	342	* The GPIO descriptors were retrieved with GPIOD_ASIS so here
	343	* we set the GPIO into output mode, carefully preserving the
	344	* current value by setting it to whatever it is already set
	345	* (no surprise changes in default fan speed).
	346	*/
	347	err = gpiod_direction_output(gpios[i],
	348	gpiod_get_value_cansleep(gpios[i]));
d00985f3 GR	349	if (err)
d00985f3 GR	350	return err;
d6fe1360 SG	351	}
d6fe1360 SG	352
d6fe1360 SG	353	fan_data->pwm_enable = true; /* Enable manual fan speed control. */
d6fe1360 SG	354	fan_data->speed_index = get_fan_speed_index(fan_data);
d00985f3	355	if (fan_data->speed_index < 0)
c52ae3d2	356	return fan_data->speed_index;
d6fe1360	357
c81cc5a4	358	return 0;
d6fe1360 SG	359	}
d6fe1360 SG	360
b5cf88e4 NM	361	static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
	362	unsigned long *state)
	363	{
	364	struct gpio_fan_data *fan_data = cdev->devdata;
	365
	366	if (!fan_data)
	367	return -EINVAL;
	368
	369	*state = fan_data->num_speed - 1;
	370	return 0;
	371	}
	372
	373	static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
	374	unsigned long *state)
	375	{
	376	struct gpio_fan_data *fan_data = cdev->devdata;
b5cf88e4 NM	377
	378	if (!fan_data)
	379	return -EINVAL;
	380
000e0949	381	*state = fan_data->speed_index;
b5cf88e4 NM	382	return 0;
	383	}
	384
	385	static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
	386	unsigned long state)
	387	{
	388	struct gpio_fan_data *fan_data = cdev->devdata;
	389
	390	if (!fan_data)
	391	return -EINVAL;
	392
f233d2be AW	393	if (state >= fan_data->num_speed)
	394	return -EINVAL;
	395
b5cf88e4 NM	396	set_fan_speed(fan_data, state);
	397	return 0;
	398	}
	399
	400	static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
	401	.get_max_state = gpio_fan_get_max_state,
	402	.get_cur_state = gpio_fan_get_cur_state,
	403	.set_cur_state = gpio_fan_set_cur_state,
	404	};
	405
55fb8b06 JL	406	/*
	407	* Translate OpenFirmware node properties into platform_data
	408	*/
b5482f7e	409	static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
55fb8b06	410	{
55fb8b06	411	struct gpio_fan_speed *speed;
b5482f7e LW	412	struct device *dev = fan_data->dev;
b5482f7e LW	413	struct device_node *np = dev->of_node;
9de382fd	414	struct gpio_desc **gpios;
55fb8b06 JL	415	unsigned i;
	416	u32 u;
	417	struct property *prop;
	418	const __be32 *p;
	419
73ef85f4	420	/* Alarm GPIO if one exists */
9de382fd LW	421	fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
	422	if (IS_ERR(fan_data->alarm_gpio))
	423	return PTR_ERR(fan_data->alarm_gpio);
73ef85f4	424
55fb8b06	425	/* Fill GPIO pin array */
9de382fd	426	fan_data->num_gpios = gpiod_count(dev, NULL);
e99c2e5d	427	if (fan_data->num_gpios <= 0) {
c9933cb1	428	if (fan_data->alarm_gpio)
73ef85f4 SG	429	return 0;
73ef85f4 SG	430	dev_err(dev, "DT properties empty / missing");
55fb8b06 JL	431	return -ENODEV;
55fb8b06 JL	432	}
a86854d0 KC	433	gpios = devm_kcalloc(dev,
a86854d0 KC	434	fan_data->num_gpios, sizeof(struct gpio_desc *),
9de382fd	435	GFP_KERNEL);
e99c2e5d	436	if (!gpios)
55fb8b06	437	return -ENOMEM;
e99c2e5d	438	for (i = 0; i < fan_data->num_gpios; i++) {
9de382fd LW	439	gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
	440	if (IS_ERR(gpios[i]))
	441	return PTR_ERR(gpios[i]);
55fb8b06	442	}
e99c2e5d	443	fan_data->gpios = gpios;
55fb8b06 JL	444
55fb8b06 JL	445	/* Get number of RPM/ctrl_val pairs in speed map */
b5482f7e	446	prop = of_find_property(np, "gpio-fan,speed-map", &i);
55fb8b06 JL	447	if (!prop) {
	448	dev_err(dev, "gpio-fan,speed-map DT property missing");
	449	return -ENODEV;
	450	}
	451	i = i / sizeof(u32);
	452	if (i == 0 \|\| i & 1) {
	453	dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
	454	return -ENODEV;
	455	}
b5482f7e	456	fan_data->num_speed = i / 2;
55fb8b06 JL	457
	458	/*
	459	* Populate speed map
	460	* Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
	461	* this needs splitting into pairs to create gpio_fan_speed structs
	462	*/
a86854d0 KC	463	speed = devm_kcalloc(dev,
a86854d0 KC	464	fan_data->num_speed, sizeof(struct gpio_fan_speed),
55fb8b06 JL	465	GFP_KERNEL);
	466	if (!speed)
	467	return -ENOMEM;
	468	p = NULL;
b5482f7e	469	for (i = 0; i < fan_data->num_speed; i++) {
55fb8b06 JL	470	p = of_prop_next_u32(prop, p, &u);
	471	if (!p)
	472	return -ENODEV;
	473	speed[i].rpm = u;
	474	p = of_prop_next_u32(prop, p, &u);
	475	if (!p)
	476	return -ENODEV;
	477	speed[i].ctrl_val = u;
	478	}
b5482f7e	479	fan_data->speed = speed;
55fb8b06	480
55fb8b06 JL	481	return 0;
	482	}
	483
6de709c5	484	static const struct of_device_id of_gpio_fan_match[] = {
55fb8b06 JL	485	{ .compatible = "gpio-fan", },
	486	{},
	487	};
fe515288	488	MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
55fb8b06	489
95347845 GR	490	static void gpio_fan_stop(void *data)
	491	{
	492	set_fan_speed(data, 0);
	493	}
	494
6c931ae1	495	static int gpio_fan_probe(struct platform_device *pdev)
d6fe1360 SG	496	{
	497	int err;
	498	struct gpio_fan_data *fan_data;
f9013c16 LW	499	struct device *dev = &pdev->dev;
f9013c16 LW	500	struct device_node *np = dev->of_node;
d6fe1360	501
f9013c16	502	fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
b5cf88e4 NM	503	GFP_KERNEL);
	504	if (!fan_data)
	505	return -ENOMEM;
	506
534e28d8	507	fan_data->dev = dev;
b5482f7e	508	err = gpio_fan_get_of_data(fan_data);
a9b4c8af LW	509	if (err)
a9b4c8af LW	510	return err;
d6fe1360	511
d6fe1360 SG	512	platform_set_drvdata(pdev, fan_data);
	513	mutex_init(&fan_data->lock);
	514
d6fe1360	515	/* Configure control GPIOs if available. */
e99c2e5d	516	if (fan_data->gpios && fan_data->num_gpios > 0) {
b5482f7e	517	if (!fan_data->speed \|\| fan_data->num_speed <= 1)
c81cc5a4	518	return -EINVAL;
b5482f7e	519	err = fan_ctrl_init(fan_data);
d6fe1360	520	if (err)
c81cc5a4	521	return err;
b9bb92e1 GR	522	err = devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
	523	if (err)
	524	return err;
d6fe1360 SG	525	}
d6fe1360 SG	526
d6fe1360	527	/* Make this driver part of hwmon class. */
49153b09	528	fan_data->hwmon_dev =
f9013c16	529	devm_hwmon_device_register_with_groups(dev,
49153b09 AL	530	"gpio_fan", fan_data,
49153b09 AL	531	gpio_fan_groups);
7258a125 GR	532	if (IS_ERR(fan_data->hwmon_dev))
7258a125 GR	533	return PTR_ERR(fan_data->hwmon_dev);
a9b4c8af	534
f2173fa2 CS	535	/* Configure alarm GPIO if available. */
	536	if (fan_data->alarm_gpio) {
	537	err = fan_alarm_init(fan_data);
	538	if (err)
	539	return err;
	540	}
	541
e76ea261	542	/* Optional cooling device register for Device tree platforms */
95347845 GR	543	fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
95347845 GR	544	"gpio-fan", fan_data, &gpio_fan_cool_ops);
d6fe1360	545
f9013c16	546	dev_info(dev, "GPIO fan initialized\n");
d6fe1360 SG	547
d6fe1360 SG	548	return 0;
d6fe1360 SG	549	}
d6fe1360 SG	550
95347845	551	static void gpio_fan_shutdown(struct platform_device *pdev)
b95579cd	552	{
b5cf88e4 NM	553	struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
b5cf88e4 NM	554
e99c2e5d	555	if (fan_data->gpios)
b95579cd NM	556	set_fan_speed(fan_data, 0);
	557	}
	558
6d20a6c0	559	static int gpio_fan_suspend(struct device *dev)
d6fe1360	560	{
6d20a6c0	561	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
d6fe1360	562
e99c2e5d	563	if (fan_data->gpios) {
d6fe1360 SG	564	fan_data->resume_speed = fan_data->speed_index;
	565	set_fan_speed(fan_data, 0);
	566	}
	567
	568	return 0;
	569	}
	570
6d20a6c0	571	static int gpio_fan_resume(struct device *dev)
d6fe1360	572	{
6d20a6c0	573	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
d6fe1360	574
e99c2e5d	575	if (fan_data->gpios)
d6fe1360 SG	576	set_fan_speed(fan_data, fan_data->resume_speed);
	577
	578	return 0;
	579	}
6d20a6c0	580
5e866400	581	static DEFINE_SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
d6fe1360 SG	582
	583	static struct platform_driver gpio_fan_driver = {
	584	.probe = gpio_fan_probe,
b95579cd	585	.shutdown = gpio_fan_shutdown,
d6fe1360 SG	586	.driver = {
d6fe1360 SG	587	.name = "gpio-fan",
5e866400	588	.pm = pm_sleep_ptr(&gpio_fan_pm),
8107fe93	589	.of_match_table = of_gpio_fan_match,
d6fe1360 SG	590	},
	591	};
	592
25a236a5	593	module_platform_driver(gpio_fan_driver);
d6fe1360 SG	594
	595	MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
	596	MODULE_DESCRIPTION("GPIO FAN driver");
	597	MODULE_LICENSE("GPL");
	598	MODULE_ALIAS("platform:gpio-fan");