linux-imx

/*

 * 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/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;

#ifdef CONFIG_PM_SLEEP

    int         resume_speed;

#endif

    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->dev->kobj, NULL, "fan1_alarm");

    kobject_uevent(&fan_data->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);