[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / hwmon / gpio-fan.c

/*
 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
 *
 * Copyright (C) 2010 LaCie
 *
 * Author: Simon Guinot <sguinot@lacie.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#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/mutex.h>
#include <linux/hwmon.h>
#include <linux/gpio.h>
#include <linux/gpio-fan.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>

struct gpio_fan_data {
	struct platform_device	*pdev;
	struct device		*hwmon_dev;
	struct mutex		lock; /* lock GPIOs operations. */
	int			num_ctrl;
	unsigned		*ctrl;
	int			num_speed;
	struct gpio_fan_speed	*speed;
	int			speed_index;
#ifdef CONFIG_PM_SLEEP
	int			resume_speed;
#endif
	bool			pwm_enable;
	struct gpio_fan_alarm	*alarm;
	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->pdev->dev.kobj, NULL, "fan1_alarm");
	kobject_uevent(&fan_data->pdev->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 show_fan_alarm(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	struct gpio_fan_alarm *alarm = fan_data->alarm;
	int value = gpio_get_value(alarm->gpio);

	if (alarm->active_low)
		value = !value;

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

static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);

static int fan_alarm_init(struct gpio_fan_data *fan_data,
			  struct gpio_fan_alarm *alarm)
{
	int err;
	int alarm_irq;
	struct platform_device *pdev = fan_data->pdev;

	fan_data->alarm = alarm;

	err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
	if (err)
		return err;

	err = gpio_direction_input(alarm->gpio);
	if (err)
		return err;

	/*
	 * If the alarm GPIO don't support interrupts, just leave
	 * without initializing the fail notification support.
	 */
	alarm_irq = gpio_to_irq(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);
	err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
			       IRQF_SHARED, "GPIO fan alarm", fan_data);
	return err;
}

/*
 * 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_ctrl; i++)
		gpio_set_value(fan_data->ctrl[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_ctrl; i++) {
		int value;

		value = gpio_get_value(fan_data->ctrl[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->pdev->dev,
		 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);

	return -EINVAL;
}

static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int 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 show_pwm(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 set_pwm(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 show_pwm_enable(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 set_pwm_enable(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 show_pwm_mode(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "0\n");
}

static ssize_t show_rpm_min(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 show_rpm_max(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 show_rpm(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 ssize_t show_name(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "gpio-fan\n");
}

static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
		   show_pwm_enable, set_pwm_enable);
static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);

static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

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

	if (index == 1 && !data->alarm)
		return 0;
	if (index > 1 && !data->ctrl)
		return 0;

	return attr->mode;
}

static struct attribute *gpio_fan_attributes[] = {
	&dev_attr_name.attr,
	&dev_attr_fan1_alarm.attr,		/* 1 */
	&dev_attr_pwm1.attr,			/* 2 */
	&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 int fan_ctrl_init(struct gpio_fan_data *fan_data,
			 struct gpio_fan_platform_data *pdata)
{
	struct platform_device *pdev = fan_data->pdev;
	int num_ctrl = pdata->num_ctrl;
	unsigned *ctrl = pdata->ctrl;
	int i, err;

	for (i = 0; i < num_ctrl; i++) {
		err = devm_gpio_request(&pdev->dev, ctrl[i],
					"GPIO fan control");
		if (err)
			return err;

		err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
		if (err)
			return err;
	}

	fan_data->num_ctrl = num_ctrl;
	fan_data->ctrl = ctrl;
	fan_data->num_speed = pdata->num_speed;
	fan_data->speed = pdata->speed;
	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 -ENODEV;

	return 0;
}

#ifdef CONFIG_OF_GPIO
/*
 * Translate OpenFirmware node properties into platform_data
 */
static int gpio_fan_get_of_pdata(struct device *dev,
			    struct gpio_fan_platform_data *pdata)
{
	struct device_node *node;
	struct gpio_fan_speed *speed;
	unsigned *ctrl;
	unsigned i;
	u32 u;
	struct property *prop;
	const __be32 *p;

	node = dev->of_node;

	/* Fill GPIO pin array */
	pdata->num_ctrl = of_gpio_count(node);
	if (pdata->num_ctrl <= 0) {
		dev_err(dev, "gpios DT property empty / missing");
		return -ENODEV;
	}
	ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
				GFP_KERNEL);
	if (!ctrl)
		return -ENOMEM;
	for (i = 0; i < pdata->num_ctrl; i++) {
		int val;

		val = of_get_gpio(node, i);
		if (val < 0)
			return val;
		ctrl[i] = val;
	}
	pdata->ctrl = ctrl;

	/* Get number of RPM/ctrl_val pairs in speed map */
	prop = of_find_property(node, "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;
	}
	pdata->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_kzalloc(dev,
			pdata->num_speed * sizeof(struct gpio_fan_speed),
			GFP_KERNEL);
	if (!speed)
		return -ENOMEM;
	p = NULL;
	for (i = 0; i < pdata->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;
	}
	pdata->speed = speed;

	/* Alarm GPIO if one exists */
	if (of_gpio_named_count(node, "alarm-gpios") > 0) {
		struct gpio_fan_alarm *alarm;
		int val;
		enum of_gpio_flags flags;

		alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
					GFP_KERNEL);
		if (!alarm)
			return -ENOMEM;

		val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
		if (val < 0)
			return val;
		alarm->gpio = val;
		alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;

		pdata->alarm = alarm;
	}

	return 0;
}

static struct of_device_id of_gpio_fan_match[] = {
	{ .compatible = "gpio-fan", },
	{},
};
#endif /* CONFIG_OF_GPIO */

static int gpio_fan_probe(struct platform_device *pdev)
{
	int err;
	struct gpio_fan_data *fan_data;
	struct gpio_fan_platform_data *pdata = pdev->dev.platform_data;

#ifdef CONFIG_OF_GPIO
	if (!pdata) {
		pdata = devm_kzalloc(&pdev->dev,
					sizeof(struct gpio_fan_platform_data),
					GFP_KERNEL);
		if (!pdata)
			return -ENOMEM;

		err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
		if (err)
			return err;
	}
#else /* CONFIG_OF_GPIO */
	if (!pdata)
		return -EINVAL;
#endif /* CONFIG_OF_GPIO */

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

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

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

	/* Configure control GPIOs if available. */
	if (pdata->ctrl && pdata->num_ctrl > 0) {
		if (!pdata->speed || pdata->num_speed <= 1)
			return -EINVAL;
		err = fan_ctrl_init(fan_data, pdata);
		if (err)
			return err;
	}

	err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_group);
	if (err)
		return err;

	/* Make this driver part of hwmon class. */
	fan_data->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(fan_data->hwmon_dev)) {
		err = PTR_ERR(fan_data->hwmon_dev);
		goto err_remove;
	}

	dev_info(&pdev->dev, "GPIO fan initialized\n");

	return 0;

err_remove:
	sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);
	return err;
}

static int gpio_fan_remove(struct platform_device *pdev)
{
	struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);

	hwmon_device_unregister(fan_data->hwmon_dev);
	sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);

	return 0;
}

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

	if (fan_data->ctrl) {
		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->ctrl)
		set_fan_speed(fan_data, fan_data->resume_speed);

	return 0;
}

static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
#define GPIO_FAN_PM	(&gpio_fan_pm)
#else
#define GPIO_FAN_PM	NULL
#endif

static struct platform_driver gpio_fan_driver = {
	.probe		= gpio_fan_probe,
	.remove		= gpio_fan_remove,
	.driver	= {
		.name	= "gpio-fan",
		.pm	= GPIO_FAN_PM,
#ifdef CONFIG_OF_GPIO
		.of_match_table = of_match_ptr(of_gpio_fan_match),
#endif
	},
};

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
d6fe1360 SG	1	/*
	2	* gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
	3	*
	4	* Copyright (C) 2010 LaCie
	5	*
	6	* Author: Simon Guinot <sguinot@lacie.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/init.h>
	25	#include <linux/slab.h>
	26	#include <linux/interrupt.h>
	27	#include <linux/irq.h>
	28	#include <linux/platform_device.h>
	29	#include <linux/err.h>
	30	#include <linux/mutex.h>
	31	#include <linux/hwmon.h>
	32	#include <linux/gpio.h>
	33	#include <linux/gpio-fan.h>
55fb8b06 JL	34	#include <linux/of_platform.h>
55fb8b06 JL	35	#include <linux/of_gpio.h>
d6fe1360 SG	36
	37	struct gpio_fan_data {
	38	struct platform_device *pdev;
	39	struct device *hwmon_dev;
	40	struct mutex lock; /* lock GPIOs operations. */
	41	int num_ctrl;
	42	unsigned *ctrl;
	43	int num_speed;
	44	struct gpio_fan_speed *speed;
	45	int speed_index;
6d20a6c0	46	#ifdef CONFIG_PM_SLEEP
d6fe1360 SG	47	int resume_speed;
	48	#endif
	49	bool pwm_enable;
	50	struct gpio_fan_alarm *alarm;
	51	struct work_struct alarm_work;
	52	};
	53
	54	/*
	55	* Alarm GPIO.
	56	*/
	57
	58	static void fan_alarm_notify(struct work_struct *ws)
	59	{
	60	struct gpio_fan_data *fan_data =
	61	container_of(ws, struct gpio_fan_data, alarm_work);
	62
	63	sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
	64	kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
	65	}
	66
	67	static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
	68	{
	69	struct gpio_fan_data *fan_data = dev_id;
	70
	71	schedule_work(&fan_data->alarm_work);
	72
	73	return IRQ_NONE;
	74	}
	75
	76	static ssize_t show_fan_alarm(struct device *dev,
	77	struct device_attribute attr, char buf)
	78	{
	79	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	80	struct gpio_fan_alarm *alarm = fan_data->alarm;
	81	int value = gpio_get_value(alarm->gpio);
	82
	83	if (alarm->active_low)
	84	value = !value;
	85
	86	return sprintf(buf, "%d\n", value);
	87	}
	88
	89	static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
	90
	91	static int fan_alarm_init(struct gpio_fan_data *fan_data,
	92	struct gpio_fan_alarm *alarm)
	93	{
	94	int err;
	95	int alarm_irq;
	96	struct platform_device *pdev = fan_data->pdev;
	97
	98	fan_data->alarm = alarm;
	99
d00985f3	100	err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
d6fe1360 SG	101	if (err)
	102	return err;
	103
	104	err = gpio_direction_input(alarm->gpio);
	105	if (err)
d00985f3	106	return err;
d6fe1360	107
d6fe1360 SG	108	/*
	109	* If the alarm GPIO don't support interrupts, just leave
	110	* without initializing the fail notification support.
	111	*/
	112	alarm_irq = gpio_to_irq(alarm->gpio);
	113	if (alarm_irq < 0)
	114	return 0;
	115
	116	INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
dced35ae	117	irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
d00985f3 GR	118	err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
d00985f3 GR	119	IRQF_SHARED, "GPIO fan alarm", fan_data);
d6fe1360 SG	120	return err;
	121	}
	122
d6fe1360 SG	123	/*
	124	* Control GPIOs.
	125	*/
	126
	127	/* Must be called with fan_data->lock held, except during initialization. */
	128	static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
	129	{
	130	int i;
	131
	132	for (i = 0; i < fan_data->num_ctrl; i++)
	133	gpio_set_value(fan_data->ctrl[i], (ctrl_val >> i) & 1);
	134	}
	135
	136	static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
	137	{
	138	int i;
	139	int ctrl_val = 0;
	140
	141	for (i = 0; i < fan_data->num_ctrl; i++) {
	142	int value;
	143
	144	value = gpio_get_value(fan_data->ctrl[i]);
	145	ctrl_val \|= (value << i);
	146	}
	147	return ctrl_val;
	148	}
	149
	150	/* Must be called with fan_data->lock held, except during initialization. */
	151	static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
	152	{
	153	if (fan_data->speed_index == speed_index)
	154	return;
	155
	156	__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
	157	fan_data->speed_index = speed_index;
	158	}
	159
	160	static int get_fan_speed_index(struct gpio_fan_data *fan_data)
	161	{
	162	int ctrl_val = __get_fan_ctrl(fan_data);
	163	int i;
	164
	165	for (i = 0; i < fan_data->num_speed; i++)
	166	if (fan_data->speed[i].ctrl_val == ctrl_val)
	167	return i;
	168
	169	dev_warn(&fan_data->pdev->dev,
	170	"missing speed array entry for GPIO value 0x%x\n", ctrl_val);
	171
	172	return -EINVAL;
	173	}
	174
	175	static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
	176	{
	177	struct gpio_fan_speed *speed = fan_data->speed;
	178	int i;
	179
	180	for (i = 0; i < fan_data->num_speed; i++)
	181	if (speed[i].rpm >= rpm)
	182	return i;
	183
	184	return fan_data->num_speed - 1;
	185	}
	186
187	static ssize_t show_pwm(struct device *dev,
188	struct device_attribute attr, char buf)
189	{
190	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
191	u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
192
193	return sprintf(buf, "%d\n", pwm);
194	}
195
196	static ssize_t set_pwm(struct device dev, struct device_attribute attr,
197	const char *buf, size_t count)
198	{
199	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
200	unsigned long pwm;
201	int speed_index;
202	int ret = count;
203
179c4fdb	204	if (kstrtoul(buf, 10, &pwm) \|\| pwm > 255)
d6fe1360 SG	205	return -EINVAL;
	206
	207	mutex_lock(&fan_data->lock);
	208
	209	if (!fan_data->pwm_enable) {
	210	ret = -EPERM;
	211	goto exit_unlock;
	212	}
	213
	214	speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
	215	set_fan_speed(fan_data, speed_index);
	216
	217	exit_unlock:
	218	mutex_unlock(&fan_data->lock);
	219
	220	return ret;
	221	}
	222
	223	static ssize_t show_pwm_enable(struct device *dev,
	224	struct device_attribute attr, char buf)
	225	{
	226	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	227
	228	return sprintf(buf, "%d\n", fan_data->pwm_enable);
	229	}
	230
	231	static ssize_t set_pwm_enable(struct device dev, struct device_attribute attr,
	232	const char *buf, size_t count)
	233	{
	234	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	235	unsigned long val;
	236
179c4fdb	237	if (kstrtoul(buf, 10, &val) \|\| val > 1)
d6fe1360 SG	238	return -EINVAL;
	239
	240	if (fan_data->pwm_enable == val)
	241	return count;
	242
	243	mutex_lock(&fan_data->lock);
	244
	245	fan_data->pwm_enable = val;
	246
	247	/* Disable manual control mode: set fan at full speed. */
	248	if (val == 0)
	249	set_fan_speed(fan_data, fan_data->num_speed - 1);
	250
	251	mutex_unlock(&fan_data->lock);
	252
	253	return count;
	254	}
	255
	256	static ssize_t show_pwm_mode(struct device *dev,
	257	struct device_attribute attr, char buf)
	258	{
	259	return sprintf(buf, "0\n");
	260	}
	261
	262	static ssize_t show_rpm_min(struct device *dev,
	263	struct device_attribute attr, char buf)
	264	{
	265	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	266
	267	return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
	268	}
	269
	270	static ssize_t show_rpm_max(struct device *dev,
	271	struct device_attribute attr, char buf)
	272	{
	273	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	274
	275	return sprintf(buf, "%d\n",
	276	fan_data->speed[fan_data->num_speed - 1].rpm);
	277	}
	278
	279	static ssize_t show_rpm(struct device *dev,
	280	struct device_attribute attr, char buf)
	281	{
	282	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	283
	284	return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
	285	}
	286
	287	static ssize_t set_rpm(struct device dev, struct device_attribute attr,
	288	const char *buf, size_t count)
	289	{
	290	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
	291	unsigned long rpm;
	292	int ret = count;
	293
179c4fdb	294	if (kstrtoul(buf, 10, &rpm))
d6fe1360 SG	295	return -EINVAL;
	296
	297	mutex_lock(&fan_data->lock);
	298
	299	if (!fan_data->pwm_enable) {
	300	ret = -EPERM;
	301	goto exit_unlock;
	302	}
	303
	304	set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
	305
	306	exit_unlock:
	307	mutex_unlock(&fan_data->lock);
	308
	309	return ret;
	310	}
	311
c81cc5a4 GR	312	static ssize_t show_name(struct device *dev,
	313	struct device_attribute attr, char buf)
	314	{
	315	return sprintf(buf, "gpio-fan\n");
	316	}
	317
d6fe1360 SG	318	static DEVICE_ATTR(pwm1, S_IRUGO \| S_IWUSR, show_pwm, set_pwm);
	319	static DEVICE_ATTR(pwm1_enable, S_IRUGO \| S_IWUSR,
	320	show_pwm_enable, set_pwm_enable);
	321	static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
	322	static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
	323	static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
	324	static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
	325	static DEVICE_ATTR(fan1_target, S_IRUGO \| S_IWUSR, show_rpm, set_rpm);
	326
c81cc5a4 GR	327	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	328
	329	static umode_t gpio_fan_is_visible(struct kobject *kobj,
	330	struct attribute *attr, int index)
	331	{
	332	struct device *dev = container_of(kobj, struct device, kobj);
	333	struct gpio_fan_data *data = dev_get_drvdata(dev);
	334
	335	if (index == 1 && !data->alarm)
	336	return 0;
	337	if (index > 1 && !data->ctrl)
	338	return 0;
	339
	340	return attr->mode;
	341	}
	342
	343	static struct attribute *gpio_fan_attributes[] = {
	344	&dev_attr_name.attr,
	345	&dev_attr_fan1_alarm.attr, /* 1 */
	346	&dev_attr_pwm1.attr, /* 2 */
d6fe1360 SG	347	&dev_attr_pwm1_enable.attr,
	348	&dev_attr_pwm1_mode.attr,
	349	&dev_attr_fan1_input.attr,
	350	&dev_attr_fan1_target.attr,
	351	&dev_attr_fan1_min.attr,
	352	&dev_attr_fan1_max.attr,
	353	NULL
	354	};
	355
c81cc5a4 GR	356	static const struct attribute_group gpio_fan_group = {
	357	.attrs = gpio_fan_attributes,
	358	.is_visible = gpio_fan_is_visible,
d6fe1360 SG	359	};
	360
	361	static int fan_ctrl_init(struct gpio_fan_data *fan_data,
	362	struct gpio_fan_platform_data *pdata)
	363	{
	364	struct platform_device *pdev = fan_data->pdev;
	365	int num_ctrl = pdata->num_ctrl;
	366	unsigned *ctrl = pdata->ctrl;
	367	int i, err;
	368
	369	for (i = 0; i < num_ctrl; i++) {
d00985f3 GR	370	err = devm_gpio_request(&pdev->dev, ctrl[i],
d00985f3 GR	371	"GPIO fan control");
d6fe1360	372	if (err)
d00985f3	373	return err;
d6fe1360 SG	374
d6fe1360 SG	375	err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
d00985f3 GR	376	if (err)
d00985f3 GR	377	return err;
d6fe1360 SG	378	}
d6fe1360 SG	379
d6fe1360 SG	380	fan_data->num_ctrl = num_ctrl;
	381	fan_data->ctrl = ctrl;
	382	fan_data->num_speed = pdata->num_speed;
	383	fan_data->speed = pdata->speed;
	384	fan_data->pwm_enable = true; /* Enable manual fan speed control. */
	385	fan_data->speed_index = get_fan_speed_index(fan_data);
d00985f3 GR	386	if (fan_data->speed_index < 0)
d00985f3 GR	387	return -ENODEV;
d6fe1360	388
c81cc5a4	389	return 0;
d6fe1360 SG	390	}
d6fe1360 SG	391
55fb8b06 JL	392	#ifdef CONFIG_OF_GPIO
	393	/*
	394	* Translate OpenFirmware node properties into platform_data
	395	*/
	396	static int gpio_fan_get_of_pdata(struct device *dev,
	397	struct gpio_fan_platform_data *pdata)
	398	{
	399	struct device_node *node;
	400	struct gpio_fan_speed *speed;
	401	unsigned *ctrl;
	402	unsigned i;
	403	u32 u;
	404	struct property *prop;
	405	const __be32 *p;
	406
	407	node = dev->of_node;
	408
	409	/* Fill GPIO pin array */
	410	pdata->num_ctrl = of_gpio_count(node);
e80beb27	411	if (pdata->num_ctrl <= 0) {
55fb8b06 JL	412	dev_err(dev, "gpios DT property empty / missing");
	413	return -ENODEV;
	414	}
	415	ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
	416	GFP_KERNEL);
	417	if (!ctrl)
	418	return -ENOMEM;
	419	for (i = 0; i < pdata->num_ctrl; i++) {
	420	int val;
	421
	422	val = of_get_gpio(node, i);
	423	if (val < 0)
	424	return val;
	425	ctrl[i] = val;
	426	}
	427	pdata->ctrl = ctrl;
	428
	429	/* Get number of RPM/ctrl_val pairs in speed map */
	430	prop = of_find_property(node, "gpio-fan,speed-map", &i);
	431	if (!prop) {
	432	dev_err(dev, "gpio-fan,speed-map DT property missing");
	433	return -ENODEV;
	434	}
	435	i = i / sizeof(u32);
	436	if (i == 0 \|\| i & 1) {
	437	dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
	438	return -ENODEV;
	439	}
	440	pdata->num_speed = i / 2;
	441
	442	/*
	443	* Populate speed map
	444	* Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
	445	* this needs splitting into pairs to create gpio_fan_speed structs
	446	*/
	447	speed = devm_kzalloc(dev,
	448	pdata->num_speed * sizeof(struct gpio_fan_speed),
	449	GFP_KERNEL);
	450	if (!speed)
	451	return -ENOMEM;
	452	p = NULL;
	453	for (i = 0; i < pdata->num_speed; i++) {
	454	p = of_prop_next_u32(prop, p, &u);
	455	if (!p)
	456	return -ENODEV;
	457	speed[i].rpm = u;
	458	p = of_prop_next_u32(prop, p, &u);
	459	if (!p)
	460	return -ENODEV;
	461	speed[i].ctrl_val = u;
	462	}
	463	pdata->speed = speed;
	464
	465	/* Alarm GPIO if one exists */
e80beb27	466	if (of_gpio_named_count(node, "alarm-gpios") > 0) {
55fb8b06 JL	467	struct gpio_fan_alarm *alarm;
	468	int val;
	469	enum of_gpio_flags flags;
	470
	471	alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
	472	GFP_KERNEL);
	473	if (!alarm)
	474	return -ENOMEM;
	475
	476	val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
	477	if (val < 0)
	478	return val;
	479	alarm->gpio = val;
	480	alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
	481
	482	pdata->alarm = alarm;
	483	}
	484
	485	return 0;
	486	}
	487
a5977246	488	static struct of_device_id of_gpio_fan_match[] = {
55fb8b06 JL	489	{ .compatible = "gpio-fan", },
	490	{},
	491	};
	492	#endif /* CONFIG_OF_GPIO */
	493
6c931ae1	494	static int gpio_fan_probe(struct platform_device *pdev)
d6fe1360 SG	495	{
	496	int err;
	497	struct gpio_fan_data *fan_data;
	498	struct gpio_fan_platform_data *pdata = pdev->dev.platform_data;
	499
55fb8b06 JL	500	#ifdef CONFIG_OF_GPIO
	501	if (!pdata) {
	502	pdata = devm_kzalloc(&pdev->dev,
	503	sizeof(struct gpio_fan_platform_data),
	504	GFP_KERNEL);
	505	if (!pdata)
	506	return -ENOMEM;
	507
	508	err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
	509	if (err)
	510	return err;
	511	}
	512	#else /* CONFIG_OF_GPIO */
d6fe1360 SG	513	if (!pdata)
d6fe1360 SG	514	return -EINVAL;
55fb8b06	515	#endif /* CONFIG_OF_GPIO */
d6fe1360	516
d00985f3 GR	517	fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
d00985f3 GR	518	GFP_KERNEL);
d6fe1360 SG	519	if (!fan_data)
	520	return -ENOMEM;
	521
	522	fan_data->pdev = pdev;
	523	platform_set_drvdata(pdev, fan_data);
	524	mutex_init(&fan_data->lock);
	525
	526	/* Configure alarm GPIO if available. */
	527	if (pdata->alarm) {
	528	err = fan_alarm_init(fan_data, pdata->alarm);
	529	if (err)
d00985f3	530	return err;
d6fe1360 SG	531	}
	532
	533	/* Configure control GPIOs if available. */
	534	if (pdata->ctrl && pdata->num_ctrl > 0) {
c81cc5a4 GR	535	if (!pdata->speed \|\| pdata->num_speed <= 1)
c81cc5a4 GR	536	return -EINVAL;
d6fe1360 SG	537	err = fan_ctrl_init(fan_data, pdata);
d6fe1360 SG	538	if (err)
c81cc5a4	539	return err;
d6fe1360 SG	540	}
d6fe1360 SG	541
c81cc5a4	542	err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_group);
d6fe1360	543	if (err)
c81cc5a4	544	return err;
d6fe1360 SG	545
	546	/* Make this driver part of hwmon class. */
	547	fan_data->hwmon_dev = hwmon_device_register(&pdev->dev);
	548	if (IS_ERR(fan_data->hwmon_dev)) {
	549	err = PTR_ERR(fan_data->hwmon_dev);
c81cc5a4	550	goto err_remove;
d6fe1360 SG	551	}
	552
	553	dev_info(&pdev->dev, "GPIO fan initialized\n");
	554
	555	return 0;
	556
c81cc5a4 GR	557	err_remove:
c81cc5a4 GR	558	sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);
d6fe1360 SG	559	return err;
	560	}
	561
281dfd0b	562	static int gpio_fan_remove(struct platform_device *pdev)
d6fe1360 SG	563	{
	564	struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
	565
	566	hwmon_device_unregister(fan_data->hwmon_dev);
c81cc5a4	567	sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_group);
d6fe1360 SG	568
	569	return 0;
	570	}
	571
6d20a6c0 RW	572	#ifdef CONFIG_PM_SLEEP
6d20a6c0 RW	573	static int gpio_fan_suspend(struct device *dev)
d6fe1360	574	{
6d20a6c0	575	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
d6fe1360 SG	576
	577	if (fan_data->ctrl) {
	578	fan_data->resume_speed = fan_data->speed_index;
	579	set_fan_speed(fan_data, 0);
	580	}
	581
	582	return 0;
	583	}
	584
6d20a6c0	585	static int gpio_fan_resume(struct device *dev)
d6fe1360	586	{
6d20a6c0	587	struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
d6fe1360 SG	588
	589	if (fan_data->ctrl)
	590	set_fan_speed(fan_data, fan_data->resume_speed);
	591
	592	return 0;
	593	}
6d20a6c0 RW	594
6d20a6c0 RW	595	static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
24f9c539	596	#define GPIO_FAN_PM (&gpio_fan_pm)
d6fe1360	597	#else
6d20a6c0	598	#define GPIO_FAN_PM NULL
d6fe1360 SG	599	#endif
	600
	601	static struct platform_driver gpio_fan_driver = {
	602	.probe = gpio_fan_probe,
9e5e9b7a	603	.remove = gpio_fan_remove,
d6fe1360 SG	604	.driver = {
d6fe1360 SG	605	.name = "gpio-fan",
6d20a6c0	606	.pm = GPIO_FAN_PM,
eaa7cc60	607	#ifdef CONFIG_OF_GPIO
55fb8b06	608	.of_match_table = of_match_ptr(of_gpio_fan_match),
eaa7cc60	609	#endif
d6fe1360 SG	610	},
	611	};
	612
25a236a5	613	module_platform_driver(gpio_fan_driver);
d6fe1360 SG	614
	615	MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
	616	MODULE_DESCRIPTION("GPIO FAN driver");
	617	MODULE_LICENSE("GPL");
	618	MODULE_ALIAS("platform:gpio-fan");