[deliverable/linux.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/slab.h>
#include <linux/hrtimer.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/ktime.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;
	ktime_t t;

	data = container_of(dev, struct timed_gpio_data, dev);

	if (!hrtimer_active(&data->timer))
		return 0;

	t = hrtimer_get_remaining(&data->timer);

	return ktime_to_ms(t);
}

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, ret;

	if (!pdata)
		return -EBUSY;

	gpio_data = devm_kcalloc(&pdev->dev, pdata->num_gpios,
				 sizeof(*gpio_data), 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 = gpio_request(cur_gpio->gpio, cur_gpio->name);
		if (ret < 0)
			goto err_out;
		ret = timed_output_dev_register(&gpio_dat->dev);
		if (ret < 0) {
			gpio_free(cur_gpio->gpio);
			goto err_out;
		}

		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;

err_out:
	while (--i >= 0) {
		timed_output_dev_unregister(&gpio_data[i].dev);
		gpio_free(gpio_data[i].gpio);
	}

	return ret;
}

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);
		gpio_free(gpio_data[i].gpio);
	}

	return 0;
}

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

module_platform_driver(timed_gpio_driver);

MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("timed gpio driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
355b0502 GKH	1	/* drivers/misc/timed_gpio.c
	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>
c1b197ae	19	#include <linux/slab.h>
355b0502 GKH	20	#include <linux/hrtimer.h>
	21	#include <linux/err.h>
	22	#include <linux/gpio.h>
d2b77871	23	#include <linux/ktime.h>
355b0502 GKH	24
	25	#include "timed_output.h"
	26	#include "timed_gpio.h"
	27
355b0502 GKH	28	struct timed_gpio_data {
	29	struct timed_output_dev dev;
	30	struct hrtimer timer;
	31	spinlock_t lock;
e3251e0d TD	32	unsigned gpio;
	33	int max_timeout;
	34	u8 active_low;
355b0502 GKH	35	};
	36
	37	static enum hrtimer_restart gpio_timer_func(struct hrtimer *timer)
	38	{
	39	struct timed_gpio_data *data =
	40	container_of(timer, struct timed_gpio_data, timer);
	41
	42	gpio_direction_output(data->gpio, data->active_low ? 1 : 0);
	43	return HRTIMER_NORESTART;
	44	}
	45
	46	static int gpio_get_time(struct timed_output_dev *dev)
	47	{
80039faa	48	struct timed_gpio_data *data;
d2b77871	49	ktime_t t;
355b0502	50
80039faa	51	data = container_of(dev, struct timed_gpio_data, dev);
10f62861	52
80039faa	53	if (!hrtimer_active(&data->timer))
355b0502	54	return 0;
80039faa	55
d2b77871	56	t = hrtimer_get_remaining(&data->timer);
80039faa	57
d2b77871	58	return ktime_to_ms(t);
355b0502 GKH	59	}
	60
	61	static void gpio_enable(struct timed_output_dev *dev, int value)
	62	{
2537468c	63	struct timed_gpio_data *data =
355b0502	64	container_of(dev, struct timed_gpio_data, dev);
2537468c	65	unsigned long flags;
355b0502 GKH	66
	67	spin_lock_irqsave(&data->lock, flags);
	68
	69	/* cancel previous timer and set GPIO according to value */
	70	hrtimer_cancel(&data->timer);
	71	gpio_direction_output(data->gpio, data->active_low ? !value : !!value);
	72
	73	if (value > 0) {
	74	if (value > data->max_timeout)
	75	value = data->max_timeout;
	76
	77	hrtimer_start(&data->timer,
f8b053e3 IC	78	ktime_set(value / 1000, (value % 1000) * 1000000),
f8b053e3 IC	79	HRTIMER_MODE_REL);
355b0502 GKH	80	}
	81
	82	spin_unlock_irqrestore(&data->lock, flags);
	83	}
	84
	85	static int timed_gpio_probe(struct platform_device *pdev)
	86	{
	87	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	88	struct timed_gpio *cur_gpio;
	89	struct timed_gpio_data gpio_data, gpio_dat;
5d92f71e	90	int i, ret;
355b0502 GKH	91
	92	if (!pdata)
	93	return -EBUSY;
	94
0103fe20 AKC	95	gpio_data = devm_kcalloc(&pdev->dev, pdata->num_gpios,
0103fe20 AKC	96	sizeof(*gpio_data), GFP_KERNEL);
355b0502 GKH	97	if (!gpio_data)
	98	return -ENOMEM;
	99
	100	for (i = 0; i < pdata->num_gpios; i++) {
	101	cur_gpio = &pdata->gpios[i];
	102	gpio_dat = &gpio_data[i];
	103
	104	hrtimer_init(&gpio_dat->timer, CLOCK_MONOTONIC,
f8b053e3	105	HRTIMER_MODE_REL);
355b0502 GKH	106	gpio_dat->timer.function = gpio_timer_func;
	107	spin_lock_init(&gpio_dat->lock);
	108
	109	gpio_dat->dev.name = cur_gpio->name;
	110	gpio_dat->dev.get_time = gpio_get_time;
	111	gpio_dat->dev.enable = gpio_enable;
0445f154	112	ret = gpio_request(cur_gpio->gpio, cur_gpio->name);
5d92f71e AL	113	if (ret < 0)
	114	goto err_out;
	115	ret = timed_output_dev_register(&gpio_dat->dev);
355b0502	116	if (ret < 0) {
5d92f71e AL	117	gpio_free(cur_gpio->gpio);
5d92f71e AL	118	goto err_out;
355b0502 GKH	119	}
	120
	121	gpio_dat->gpio = cur_gpio->gpio;
	122	gpio_dat->max_timeout = cur_gpio->max_timeout;
	123	gpio_dat->active_low = cur_gpio->active_low;
	124	gpio_direction_output(gpio_dat->gpio, gpio_dat->active_low);
	125	}
	126
	127	platform_set_drvdata(pdev, gpio_data);
	128
	129	return 0;
5d92f71e AL	130
	131	err_out:
	132	while (--i >= 0) {
	133	timed_output_dev_unregister(&gpio_data[i].dev);
	134	gpio_free(gpio_data[i].gpio);
	135	}
5d92f71e AL	136
5d92f71e AL	137	return ret;
355b0502 GKH	138	}
	139
	140	static int timed_gpio_remove(struct platform_device *pdev)
	141	{
	142	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	143	struct timed_gpio_data *gpio_data = platform_get_drvdata(pdev);
	144	int i;
	145
0445f154	146	for (i = 0; i < pdata->num_gpios; i++) {
355b0502	147	timed_output_dev_unregister(&gpio_data[i].dev);
0445f154 AH	148	gpio_free(gpio_data[i].gpio);
0445f154 AH	149	}
355b0502	150
355b0502 GKH	151	return 0;
	152	}
	153
	154	static struct platform_driver timed_gpio_driver = {
	155	.probe = timed_gpio_probe,
	156	.remove = timed_gpio_remove,
	157	.driver = {
	158	.name = TIMED_GPIO_NAME,
355b0502 GKH	159	},
	160	};
	161
c21be47c	162	module_platform_driver(timed_gpio_driver);
355b0502 GKH	163
	164	MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
	165	MODULE_DESCRIPTION("timed gpio driver");
	166	MODULE_LICENSE("GPL");