[mirror_ubuntu-bionic-kernel.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_kzalloc(&pdev->dev,
			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 = 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
	28
	29	struct timed_gpio_data {
	30	struct timed_output_dev dev;
	31	struct hrtimer timer;
	32	spinlock_t lock;
e3251e0d TD	33	unsigned gpio;
	34	int max_timeout;
	35	u8 active_low;
355b0502 GKH	36	};
	37
	38	static enum hrtimer_restart gpio_timer_func(struct hrtimer *timer)
	39	{
	40	struct timed_gpio_data *data =
	41	container_of(timer, struct timed_gpio_data, timer);
	42
	43	gpio_direction_output(data->gpio, data->active_low ? 1 : 0);
	44	return HRTIMER_NORESTART;
	45	}
	46
	47	static int gpio_get_time(struct timed_output_dev *dev)
	48	{
80039faa	49	struct timed_gpio_data *data;
d2b77871	50	ktime_t t;
355b0502	51
80039faa	52	data = container_of(dev, struct timed_gpio_data, dev);
10f62861	53
80039faa	54	if (!hrtimer_active(&data->timer))
355b0502	55	return 0;
80039faa	56
d2b77871	57	t = hrtimer_get_remaining(&data->timer);
80039faa	58
d2b77871	59	return ktime_to_ms(t);
355b0502 GKH	60	}
	61
	62	static void gpio_enable(struct timed_output_dev *dev, int value)
	63	{
2537468c	64	struct timed_gpio_data *data =
355b0502	65	container_of(dev, struct timed_gpio_data, dev);
2537468c	66	unsigned long flags;
355b0502 GKH	67
	68	spin_lock_irqsave(&data->lock, flags);
	69
	70	/* cancel previous timer and set GPIO according to value */
	71	hrtimer_cancel(&data->timer);
	72	gpio_direction_output(data->gpio, data->active_low ? !value : !!value);
	73
	74	if (value > 0) {
	75	if (value > data->max_timeout)
	76	value = data->max_timeout;
	77
	78	hrtimer_start(&data->timer,
	79	ktime_set(value / 1000, (value % 1000) * 1000000),
	80	HRTIMER_MODE_REL);
	81	}
	82
	83	spin_unlock_irqrestore(&data->lock, flags);
	84	}
	85
	86	static int timed_gpio_probe(struct platform_device *pdev)
	87	{
	88	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	89	struct timed_gpio *cur_gpio;
	90	struct timed_gpio_data gpio_data, gpio_dat;
5d92f71e	91	int i, ret;
355b0502 GKH	92
	93	if (!pdata)
	94	return -EBUSY;
	95
3e4cb2f3	96	gpio_data = devm_kzalloc(&pdev->dev,
27ea2f16 JC	97	sizeof(struct timed_gpio_data) * pdata->num_gpios,
27ea2f16 JC	98	GFP_KERNEL);
355b0502 GKH	99	if (!gpio_data)
	100	return -ENOMEM;
	101
	102	for (i = 0; i < pdata->num_gpios; i++) {
	103	cur_gpio = &pdata->gpios[i];
	104	gpio_dat = &gpio_data[i];
	105
	106	hrtimer_init(&gpio_dat->timer, CLOCK_MONOTONIC,
	107	HRTIMER_MODE_REL);
	108	gpio_dat->timer.function = gpio_timer_func;
	109	spin_lock_init(&gpio_dat->lock);
	110
	111	gpio_dat->dev.name = cur_gpio->name;
	112	gpio_dat->dev.get_time = gpio_get_time;
	113	gpio_dat->dev.enable = gpio_enable;
0445f154	114	ret = gpio_request(cur_gpio->gpio, cur_gpio->name);
5d92f71e AL	115	if (ret < 0)
	116	goto err_out;
	117	ret = timed_output_dev_register(&gpio_dat->dev);
355b0502	118	if (ret < 0) {
5d92f71e AL	119	gpio_free(cur_gpio->gpio);
5d92f71e AL	120	goto err_out;
355b0502 GKH	121	}
	122
	123	gpio_dat->gpio = cur_gpio->gpio;
	124	gpio_dat->max_timeout = cur_gpio->max_timeout;
	125	gpio_dat->active_low = cur_gpio->active_low;
	126	gpio_direction_output(gpio_dat->gpio, gpio_dat->active_low);
	127	}
	128
	129	platform_set_drvdata(pdev, gpio_data);
	130
	131	return 0;
5d92f71e AL	132
	133	err_out:
	134	while (--i >= 0) {
	135	timed_output_dev_unregister(&gpio_data[i].dev);
	136	gpio_free(gpio_data[i].gpio);
	137	}
5d92f71e AL	138
5d92f71e AL	139	return ret;
355b0502 GKH	140	}
	141
	142	static int timed_gpio_remove(struct platform_device *pdev)
	143	{
	144	struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
	145	struct timed_gpio_data *gpio_data = platform_get_drvdata(pdev);
	146	int i;
	147
0445f154	148	for (i = 0; i < pdata->num_gpios; i++) {
355b0502	149	timed_output_dev_unregister(&gpio_data[i].dev);
0445f154 AH	150	gpio_free(gpio_data[i].gpio);
0445f154 AH	151	}
355b0502	152
355b0502 GKH	153	return 0;
	154	}
	155
	156	static struct platform_driver timed_gpio_driver = {
	157	.probe = timed_gpio_probe,
	158	.remove = timed_gpio_remove,
	159	.driver = {
	160	.name = TIMED_GPIO_NAME,
355b0502 GKH	161	},
	162	};
	163
c21be47c	164	module_platform_driver(timed_gpio_driver);
355b0502 GKH	165
	166	MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
	167	MODULE_DESCRIPTION("timed gpio driver");
	168	MODULE_LICENSE("GPL");