[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / staging / android / timed_gpio.c

/* drivers/misc/timed_gpio.c
 *
 * Copyright (C) 2008 Google, Inc.
 * Author: Mike Lockwood <lockwood@android.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 *
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/hrtimer.h>
#include <linux/err.h>
#include <linux/gpio.h>

#include "timed_output.h"
#include "timed_gpio.h"


struct timed_gpio_data {
	struct timed_output_dev dev;
	struct hrtimer timer;
	spinlock_t lock;
	unsigned 	gpio;
	int 		max_timeout;
	u8 		active_low;
};

static enum hrtimer_restart gpio_timer_func(struct hrtimer *timer)
{
	struct timed_gpio_data *data =
		container_of(timer, struct timed_gpio_data, timer);

	gpio_direction_output(data->gpio, data->active_low ? 1 : 0);
	return HRTIMER_NORESTART;
}

static int gpio_get_time(struct timed_output_dev *dev)
{
	struct timed_gpio_data	*data =
		container_of(dev, struct timed_gpio_data, dev);

	if (hrtimer_active(&data->timer)) {
		ktime_t r = hrtimer_get_remaining(&data->timer);
		struct timeval t = ktime_to_timeval(r);
		return t.tv_sec * 1000 + t.tv_usec / 1000;
	} else
		return 0;
}

static void gpio_enable(struct timed_output_dev *dev, int value)
{
	struct timed_gpio_data	*data =
		container_of(dev, struct timed_gpio_data, dev);
	unsigned long	flags;

	spin_lock_irqsave(&data->lock, flags);

	/* cancel previous timer and set GPIO according to value */
	hrtimer_cancel(&data->timer);
	gpio_direction_output(data->gpio, data->active_low ? !value : !!value);

	if (value > 0) {
		if (value > data->max_timeout)
			value = data->max_timeout;

		hrtimer_start(&data->timer,
			ktime_set(value / 1000, (value % 1000) * 1000000),
			HRTIMER_MODE_REL);
	}

	spin_unlock_irqrestore(&data->lock, flags);
}

static int timed_gpio_probe(struct platform_device *pdev)
{
	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	struct timed_gpio *cur_gpio;
	struct timed_gpio_data *gpio_data, *gpio_dat;
	int i, j, ret = 0;

	if (!pdata)
		return -EBUSY;

	gpio_data = kzalloc(sizeof(struct timed_gpio_data) * pdata->num_gpios,
			GFP_KERNEL);
	if (!gpio_data)
		return -ENOMEM;

	for (i = 0; i < pdata->num_gpios; i++) {
		cur_gpio = &pdata->gpios[i];
		gpio_dat = &gpio_data[i];

		hrtimer_init(&gpio_dat->timer, CLOCK_MONOTONIC,
				HRTIMER_MODE_REL);
		gpio_dat->timer.function = gpio_timer_func;
		spin_lock_init(&gpio_dat->lock);

		gpio_dat->dev.name = cur_gpio->name;
		gpio_dat->dev.get_time = gpio_get_time;
		gpio_dat->dev.enable = gpio_enable;
		ret = timed_output_dev_register(&gpio_dat->dev);
		if (ret < 0) {
			for (j = 0; j < i; j++)
				timed_output_dev_unregister(&gpio_data[i].dev);
			kfree(gpio_data);
			return ret;
		}

		gpio_dat->gpio = cur_gpio->gpio;
		gpio_dat->max_timeout = cur_gpio->max_timeout;
		gpio_dat->active_low = cur_gpio->active_low;
		gpio_direction_output(gpio_dat->gpio, gpio_dat->active_low);
	}

	platform_set_drvdata(pdev, gpio_data);

	return 0;
}

static int timed_gpio_remove(struct platform_device *pdev)
{
	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	struct timed_gpio_data *gpio_data = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < pdata->num_gpios; i++)
		timed_output_dev_unregister(&gpio_data[i].dev);

	kfree(gpio_data);

	return 0;
}

static struct platform_driver timed_gpio_driver = {
	.probe		= timed_gpio_probe,
	.remove		= timed_gpio_remove,
	.driver		= {
		.name		= TIMED_GPIO_NAME,
		.owner		= THIS_MODULE,
	},
};

static int __init timed_gpio_init(void)
{
	return platform_driver_register(&timed_gpio_driver);
}

static void __exit timed_gpio_exit(void)
{
	platform_driver_unregister(&timed_gpio_driver);
}

module_init(timed_gpio_init);
module_exit(timed_gpio_exit);

MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("timed gpio driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
653d1290	1	/* drivers/misc/timed_gpio.c
99f41131 ML	2	*
	3	* Copyright (C) 2008 Google, Inc.
	4	* Author: Mike Lockwood <lockwood@android.com>
	5	*
	6	* This software is licensed under the terms of the GNU General Public
	7	* License version 2, as published by the Free Software Foundation, and
	8	* may be copied, distributed, and modified under those terms.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	*/
	16
	17	#include <linux/module.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/hrtimer.h>
	20	#include <linux/err.h>
2d0db6bf	21	#include <linux/gpio.h>
99f41131	22
241e1287	23	#include "timed_output.h"
653d1290	24	#include "timed_gpio.h"
99f41131 ML	25
99f41131 ML	26
99f41131	27	struct timed_gpio_data {
241e1287	28	struct timed_output_dev dev;
99f41131 ML	29	struct hrtimer timer;
	30	spinlock_t lock;
	31	unsigned gpio;
	32	int max_timeout;
	33	u8 active_low;
	34	};
	35
	36	static enum hrtimer_restart gpio_timer_func(struct hrtimer *timer)
	37	{
241e1287 ML	38	struct timed_gpio_data *data =
241e1287 ML	39	container_of(timer, struct timed_gpio_data, timer);
99f41131	40
241e1287	41	gpio_direction_output(data->gpio, data->active_low ? 1 : 0);
99f41131 ML	42	return HRTIMER_NORESTART;
	43	}
	44
241e1287	45	static int gpio_get_time(struct timed_output_dev *dev)
99f41131	46	{
241e1287 ML	47	struct timed_gpio_data *data =
241e1287 ML	48	container_of(dev, struct timed_gpio_data, dev);
99f41131	49
241e1287 ML	50	if (hrtimer_active(&data->timer)) {
241e1287 ML	51	ktime_t r = hrtimer_get_remaining(&data->timer);
07960058	52	struct timeval t = ktime_to_timeval(r);
241e1287	53	return t.tv_sec * 1000 + t.tv_usec / 1000;
99f41131	54	} else
241e1287	55	return 0;
99f41131 ML	56	}
99f41131 ML	57
241e1287	58	static void gpio_enable(struct timed_output_dev *dev, int value)
99f41131	59	{
241e1287 ML	60	struct timed_gpio_data *data =
241e1287 ML	61	container_of(dev, struct timed_gpio_data, dev);
99f41131 ML	62	unsigned long flags;
99f41131 ML	63
241e1287	64	spin_lock_irqsave(&data->lock, flags);
99f41131 ML	65
99f41131 ML	66	/* cancel previous timer and set GPIO according to value */
241e1287 ML	67	hrtimer_cancel(&data->timer);
241e1287 ML	68	gpio_direction_output(data->gpio, data->active_low ? !value : !!value);
99f41131 ML	69
99f41131 ML	70	if (value > 0) {
241e1287 ML	71	if (value > data->max_timeout)
241e1287 ML	72	value = data->max_timeout;
99f41131	73
241e1287 ML	74	hrtimer_start(&data->timer,
	75	ktime_set(value / 1000, (value % 1000) * 1000000),
	76	HRTIMER_MODE_REL);
99f41131 ML	77	}
99f41131 ML	78
241e1287	79	spin_unlock_irqrestore(&data->lock, flags);
99f41131 ML	80	}
99f41131 ML	81
653d1290	82	static int timed_gpio_probe(struct platform_device *pdev)
99f41131 ML	83	{
	84	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	85	struct timed_gpio *cur_gpio;
	86	struct timed_gpio_data gpio_data, gpio_dat;
241e1287	87	int i, j, ret = 0;
99f41131 ML	88
	89	if (!pdata)
	90	return -EBUSY;
	91
241e1287 ML	92	gpio_data = kzalloc(sizeof(struct timed_gpio_data) * pdata->num_gpios,
241e1287 ML	93	GFP_KERNEL);
99f41131 ML	94	if (!gpio_data)
	95	return -ENOMEM;
	96
	97	for (i = 0; i < pdata->num_gpios; i++) {
	98	cur_gpio = &pdata->gpios[i];
	99	gpio_dat = &gpio_data[i];
	100
241e1287 ML	101	hrtimer_init(&gpio_dat->timer, CLOCK_MONOTONIC,
241e1287 ML	102	HRTIMER_MODE_REL);
99f41131 ML	103	gpio_dat->timer.function = gpio_timer_func;
	104	spin_lock_init(&gpio_dat->lock);
	105
241e1287 ML	106	gpio_dat->dev.name = cur_gpio->name;
	107	gpio_dat->dev.get_time = gpio_get_time;
	108	gpio_dat->dev.enable = gpio_enable;
	109	ret = timed_output_dev_register(&gpio_dat->dev);
	110	if (ret < 0) {
	111	for (j = 0; j < i; j++)
	112	timed_output_dev_unregister(&gpio_data[i].dev);
	113	kfree(gpio_data);
	114	return ret;
	115	}
	116
99f41131 ML	117	gpio_dat->gpio = cur_gpio->gpio;
	118	gpio_dat->max_timeout = cur_gpio->max_timeout;
	119	gpio_dat->active_low = cur_gpio->active_low;
	120	gpio_direction_output(gpio_dat->gpio, gpio_dat->active_low);
99f41131 ML	121	}
	122
	123	platform_set_drvdata(pdev, gpio_data);
	124
	125	return 0;
	126	}
	127
653d1290	128	static int timed_gpio_remove(struct platform_device *pdev)
99f41131 ML	129	{
	130	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	131	struct timed_gpio_data *gpio_data = platform_get_drvdata(pdev);
	132	int i;
	133
241e1287 ML	134	for (i = 0; i < pdata->num_gpios; i++)
241e1287 ML	135	timed_output_dev_unregister(&gpio_data[i].dev);
99f41131 ML	136
	137	kfree(gpio_data);
	138
	139	return 0;
	140	}
	141
653d1290 ML	142	static struct platform_driver timed_gpio_driver = {
	143	.probe = timed_gpio_probe,
	144	.remove = timed_gpio_remove,
99f41131	145	.driver = {
241e1287	146	.name = TIMED_GPIO_NAME,
99f41131 ML	147	.owner = THIS_MODULE,
	148	},
	149	};
	150
653d1290	151	static int __init timed_gpio_init(void)
99f41131	152	{
653d1290	153	return platform_driver_register(&timed_gpio_driver);
99f41131 ML	154	}
99f41131 ML	155
653d1290	156	static void __exit timed_gpio_exit(void)
99f41131	157	{
653d1290	158	platform_driver_unregister(&timed_gpio_driver);
99f41131 ML	159	}
99f41131 ML	160
653d1290 ML	161	module_init(timed_gpio_init);
653d1290 ML	162	module_exit(timed_gpio_exit);
99f41131 ML	163
99f41131 ML	164	MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
653d1290	165	MODULE_DESCRIPTION("timed gpio driver");
99f41131	166	MODULE_LICENSE("GPL");