[deliverable/linux.git] / drivers / extcon / extcon-gpio.c

/*
 *  drivers/extcon/extcon_gpio.c
 *
 *  Single-state GPIO extcon driver based on extcon class
 *
 * Copyright (C) 2008 Google, Inc.
 * Author: Mike Lockwood <lockwood@android.com>
 *
 * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
 * (originally switch class is supported)
 *
 * 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/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/extcon.h>
#include <linux/extcon/extcon-gpio.h>

struct gpio_extcon_data {
	struct extcon_dev *edev;
	unsigned gpio;
	bool gpio_active_low;
	const char *state_on;
	const char *state_off;
	int irq;
	struct delayed_work work;
	unsigned long debounce_jiffies;
	bool check_on_resume;
};

static void gpio_extcon_work(struct work_struct *work)
{
	int state;
	struct gpio_extcon_data	*data =
		container_of(to_delayed_work(work), struct gpio_extcon_data,
			     work);

	state = gpio_get_value(data->gpio);
	if (data->gpio_active_low)
		state = !state;
	extcon_set_state(data->edev, state);
}

static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
{
	struct gpio_extcon_data *extcon_data = dev_id;

	queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
			      extcon_data->debounce_jiffies);
	return IRQ_HANDLED;
}

static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
{
	struct device *dev = edev->dev.parent;
	struct gpio_extcon_data *extcon_data = dev_get_drvdata(dev);
	const char *state;

	if (extcon_get_state(edev))
		state = extcon_data->state_on;
	else
		state = extcon_data->state_off;

	if (state)
		return sprintf(buf, "%s\n", state);
	return -EINVAL;
}

static int gpio_extcon_probe(struct platform_device *pdev)
{
	struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct gpio_extcon_data *extcon_data;
	int ret;

	if (!pdata)
		return -EBUSY;
	if (!pdata->irq_flags) {
		dev_err(&pdev->dev, "IRQ flag is not specified.\n");
		return -EINVAL;
	}

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

	extcon_data->edev = devm_extcon_dev_allocate(&pdev->dev, NULL);
	if (IS_ERR(extcon_data->edev)) {
		dev_err(&pdev->dev, "failed to allocate extcon device\n");
		return -ENOMEM;
	}
	extcon_data->edev->name = pdata->name;
	extcon_data->edev->dev.parent = &pdev->dev;

	extcon_data->gpio = pdata->gpio;
	extcon_data->gpio_active_low = pdata->gpio_active_low;
	extcon_data->state_on = pdata->state_on;
	extcon_data->state_off = pdata->state_off;
	extcon_data->check_on_resume = pdata->check_on_resume;
	if (pdata->state_on && pdata->state_off)
		extcon_data->edev->print_state = extcon_gpio_print_state;

	ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
				    pdev->name);
	if (ret < 0)
		return ret;

	if (pdata->debounce) {
		ret = gpio_set_debounce(extcon_data->gpio,
					pdata->debounce * 1000);
		if (ret < 0)
			extcon_data->debounce_jiffies =
				msecs_to_jiffies(pdata->debounce);
	}

	ret = devm_extcon_dev_register(&pdev->dev, extcon_data->edev);
	if (ret < 0)
		return ret;

	INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);

	extcon_data->irq = gpio_to_irq(extcon_data->gpio);
	if (extcon_data->irq < 0)
		return extcon_data->irq;

	ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
				      pdata->irq_flags, pdev->name,
				      extcon_data);
	if (ret < 0)
		return ret;

	platform_set_drvdata(pdev, extcon_data);
	/* Perform initial detection */
	gpio_extcon_work(&extcon_data->work.work);

	return 0;
}

static int gpio_extcon_remove(struct platform_device *pdev)
{
	struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&extcon_data->work);
	free_irq(extcon_data->irq, extcon_data);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int gpio_extcon_resume(struct device *dev)
{
	struct gpio_extcon_data *extcon_data;

	extcon_data = dev_get_drvdata(dev);
	if (extcon_data->check_on_resume)
		queue_delayed_work(system_power_efficient_wq,
			&extcon_data->work, extcon_data->debounce_jiffies);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);

static struct platform_driver gpio_extcon_driver = {
	.probe		= gpio_extcon_probe,
	.remove		= gpio_extcon_remove,
	.driver		= {
		.name	= "extcon-gpio",
		.owner	= THIS_MODULE,
		.pm	= &gpio_extcon_pm_ops,
	},
};

module_platform_driver(gpio_extcon_driver);

MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("GPIO extcon driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
be48308a MH	1	/*
	2	* drivers/extcon/extcon_gpio.c
	3	*
	4	* Single-state GPIO extcon driver based on extcon class
	5	*
	6	* Copyright (C) 2008 Google, Inc.
	7	* Author: Mike Lockwood <lockwood@android.com>
	8	*
	9	* Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
	10	* (originally switch class is supported)
	11	*
	12	* This software is licensed under the terms of the GNU General Public
	13	* License version 2, as published by the Free Software Foundation, and
	14	* may be copied, distributed, and modified under those terms.
	15	*
	16	* This program is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	* GNU General Public License for more details.
	20	*
	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/kernel.h>
	25	#include <linux/init.h>
	26	#include <linux/interrupt.h>
	27	#include <linux/platform_device.h>
	28	#include <linux/slab.h>
be48308a MH	29	#include <linux/workqueue.h>
	30	#include <linux/gpio.h>
	31	#include <linux/extcon.h>
fd116066	32	#include <linux/extcon/extcon-gpio.h>
be48308a MH	33
be48308a MH	34	struct gpio_extcon_data {
60cd62d4	35	struct extcon_dev *edev;
be48308a	36	unsigned gpio;
5bfbdc9c	37	bool gpio_active_low;
be48308a MH	38	const char *state_on;
	39	const char *state_off;
	40	int irq;
	41	struct delayed_work work;
	42	unsigned long debounce_jiffies;
6544dfa5	43	bool check_on_resume;
be48308a MH	44	};
	45
	46	static void gpio_extcon_work(struct work_struct *work)
	47	{
	48	int state;
	49	struct gpio_extcon_data *data =
	50	container_of(to_delayed_work(work), struct gpio_extcon_data,
	51	work);
	52
	53	state = gpio_get_value(data->gpio);
5bfbdc9c GR	54	if (data->gpio_active_low)
5bfbdc9c GR	55	state = !state;
60cd62d4	56	extcon_set_state(data->edev, state);
be48308a MH	57	}
	58
	59	static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
	60	{
	61	struct gpio_extcon_data *extcon_data = dev_id;
	62
d0db2e7a	63	queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
be48308a MH	64	extcon_data->debounce_jiffies);
	65	return IRQ_HANDLED;
	66	}
	67
	68	static ssize_t extcon_gpio_print_state(struct extcon_dev edev, char buf)
	69	{
60cd62d4 CC	70	struct device *dev = edev->dev.parent;
60cd62d4 CC	71	struct gpio_extcon_data *extcon_data = dev_get_drvdata(dev);
be48308a	72	const char *state;
60cd62d4	73
be48308a MH	74	if (extcon_get_state(edev))
	75	state = extcon_data->state_on;
	76	else
	77	state = extcon_data->state_off;
	78
	79	if (state)
	80	return sprintf(buf, "%s\n", state);
	81	return -EINVAL;
	82	}
	83
44f34fd4	84	static int gpio_extcon_probe(struct platform_device *pdev)
be48308a	85	{
7c0f6558	86	struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
be48308a	87	struct gpio_extcon_data *extcon_data;
1073514b	88	int ret;
be48308a MH	89
	90	if (!pdata)
	91	return -EBUSY;
	92	if (!pdata->irq_flags) {
	93	dev_err(&pdev->dev, "IRQ flag is not specified.\n");
	94	return -EINVAL;
	95	}
	96
	97	extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
	98	GFP_KERNEL);
	99	if (!extcon_data)
	100	return -ENOMEM;
	101
60cd62d4 CC	102	extcon_data->edev = devm_extcon_dev_allocate(&pdev->dev, NULL);
	103	if (IS_ERR(extcon_data->edev)) {
	104	dev_err(&pdev->dev, "failed to allocate extcon device\n");
	105	return -ENOMEM;
	106	}
	107	extcon_data->edev->name = pdata->name;
	108	extcon_data->edev->dev.parent = &pdev->dev;
	109
be48308a	110	extcon_data->gpio = pdata->gpio;
5bfbdc9c	111	extcon_data->gpio_active_low = pdata->gpio_active_low;
be48308a MH	112	extcon_data->state_on = pdata->state_on;
be48308a MH	113	extcon_data->state_off = pdata->state_off;
6544dfa5	114	extcon_data->check_on_resume = pdata->check_on_resume;
be48308a	115	if (pdata->state_on && pdata->state_off)
60cd62d4	116	extcon_data->edev->print_state = extcon_gpio_print_state;
4288d9b8 GR	117
	118	ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
	119	pdev->name);
	120	if (ret < 0)
	121	return ret;
	122
338de0ca GR	123	if (pdata->debounce) {
	124	ret = gpio_set_debounce(extcon_data->gpio,
	125	pdata->debounce * 1000);
	126	if (ret < 0)
	127	extcon_data->debounce_jiffies =
	128	msecs_to_jiffies(pdata->debounce);
	129	}
be48308a	130
60cd62d4	131	ret = devm_extcon_dev_register(&pdev->dev, extcon_data->edev);
be48308a	132	if (ret < 0)
01eaf245	133	return ret;
be48308a	134
be48308a MH	135	INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
	136
	137	extcon_data->irq = gpio_to_irq(extcon_data->gpio);
d92c2f12 SW	138	if (extcon_data->irq < 0)
d92c2f12 SW	139	return extcon_data->irq;
be48308a MH	140
	141	ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
	142	pdata->irq_flags, pdev->name,
	143	extcon_data);
	144	if (ret < 0)
d92c2f12	145	return ret;
be48308a	146
b945f3fa	147	platform_set_drvdata(pdev, extcon_data);
be48308a MH	148	/* Perform initial detection */
	149	gpio_extcon_work(&extcon_data->work.work);
	150
	151	return 0;
be48308a MH	152	}
be48308a MH	153
93ed0327	154	static int gpio_extcon_remove(struct platform_device *pdev)
be48308a MH	155	{
	156	struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
	157
	158	cancel_delayed_work_sync(&extcon_data->work);
b945f3fa	159	free_irq(extcon_data->irq, extcon_data);
be48308a MH	160
	161	return 0;
	162	}
	163
6544dfa5 RY	164	#ifdef CONFIG_PM_SLEEP
	165	static int gpio_extcon_resume(struct device *dev)
	166	{
	167	struct gpio_extcon_data *extcon_data;
	168
	169	extcon_data = dev_get_drvdata(dev);
	170	if (extcon_data->check_on_resume)
	171	queue_delayed_work(system_power_efficient_wq,
	172	&extcon_data->work, extcon_data->debounce_jiffies);
	173
	174	return 0;
	175	}
	176	#endif
	177
3cc731d9	178	static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
6544dfa5	179
2878bda8	180	static struct platform_driver gpio_extcon_driver = {
be48308a	181	.probe = gpio_extcon_probe,
5f7e2228	182	.remove = gpio_extcon_remove,
be48308a MH	183	.driver = {
	184	.name = "extcon-gpio",
	185	.owner = THIS_MODULE,
6544dfa5	186	.pm = &gpio_extcon_pm_ops,
be48308a MH	187	},
	188	};
	189
2878bda8	190	module_platform_driver(gpio_extcon_driver);
be48308a MH	191
	192	MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
	193	MODULE_DESCRIPTION("GPIO extcon driver");
	194	MODULE_LICENSE("GPL");