[deliverable/linux.git] / drivers / staging / android / timed_output.c

/* drivers/misc/timed_output.c
 *
 * Copyright (C) 2009 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.
 *
 */

#define pr_fmt(fmt) "timed_output: " fmt

#include <linux/module.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/err.h>

#include "timed_output.h"

static struct class *timed_output_class;
static atomic_t device_count;

static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct timed_output_dev *tdev = dev_get_drvdata(dev);
	int remaining = tdev->get_time(tdev);

	return sprintf(buf, "%d\n", remaining);
}

static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t size)
{
	struct timed_output_dev *tdev = dev_get_drvdata(dev);
	int value;

	if (sscanf(buf, "%d", &value) != 1)
		return -EINVAL;

	tdev->enable(tdev, value);

	return size;
}
static DEVICE_ATTR_RW(enable);

static struct attribute *timed_output_attrs[] = {
	&dev_attr_enable.attr,
	NULL,
};
ATTRIBUTE_GROUPS(timed_output);

static int create_timed_output_class(void)
{
	if (!timed_output_class) {
		timed_output_class = class_create(THIS_MODULE, "timed_output");
		if (IS_ERR(timed_output_class))
			return PTR_ERR(timed_output_class);
		atomic_set(&device_count, 0);
		timed_output_class->dev_groups = timed_output_groups;
	}

	return 0;
}

int timed_output_dev_register(struct timed_output_dev *tdev)
{
	int ret;

	if (!tdev || !tdev->name || !tdev->enable || !tdev->get_time)
		return -EINVAL;

	ret = create_timed_output_class();
	if (ret < 0)
		return ret;

	tdev->index = atomic_inc_return(&device_count);
	tdev->dev = device_create(timed_output_class, NULL,
		MKDEV(0, tdev->index), NULL, "%s", tdev->name);
	if (IS_ERR(tdev->dev))
		return PTR_ERR(tdev->dev);

	dev_set_drvdata(tdev->dev, tdev);
	tdev->state = 0;
	return 0;
}
EXPORT_SYMBOL_GPL(timed_output_dev_register);

void timed_output_dev_unregister(struct timed_output_dev *tdev)
{
	tdev->enable(tdev, 0);
	device_destroy(timed_output_class, MKDEV(0, tdev->index));
	dev_set_drvdata(tdev->dev, NULL);
}
EXPORT_SYMBOL_GPL(timed_output_dev_unregister);

static int __init timed_output_init(void)
{
	return create_timed_output_class();
}

static void __exit timed_output_exit(void)
{
	class_destroy(timed_output_class);
}

module_init(timed_output_init);
module_exit(timed_output_exit);

MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("timed output class driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
355b0502 GKH	1	/* drivers/misc/timed_output.c
	2	*
	3	* Copyright (C) 2009 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
c810a399 SK	17	#define pr_fmt(fmt) "timed_output: " fmt
c810a399 SK	18
355b0502 GKH	19	#include <linux/module.h>
	20	#include <linux/types.h>
	21	#include <linux/device.h>
	22	#include <linux/fs.h>
	23	#include <linux/err.h>
	24
	25	#include "timed_output.h"
	26
	27	static struct class *timed_output_class;
	28	static atomic_t device_count;
	29
	30	static ssize_t enable_show(struct device dev, struct device_attribute attr,
9d3ab801	31	char *buf)
355b0502 GKH	32	{
	33	struct timed_output_dev *tdev = dev_get_drvdata(dev);
	34	int remaining = tdev->get_time(tdev);
	35
	36	return sprintf(buf, "%d\n", remaining);
	37	}
	38
9d3ab801 GKH	39	static ssize_t enable_store(struct device dev, struct device_attribute attr,
9d3ab801 GKH	40	const char *buf, size_t size)
355b0502 GKH	41	{
	42	struct timed_output_dev *tdev = dev_get_drvdata(dev);
	43	int value;
	44
8bfe15f3 ML	45	if (sscanf(buf, "%d", &value) != 1)
	46	return -EINVAL;
	47
355b0502 GKH	48	tdev->enable(tdev, value);
	49
	50	return size;
	51	}
9d3ab801	52	static DEVICE_ATTR_RW(enable);
355b0502	53
9d3ab801 GKH	54	static struct attribute *timed_output_attrs[] = {
	55	&dev_attr_enable.attr,
	56	NULL,
	57	};
	58	ATTRIBUTE_GROUPS(timed_output);
355b0502 GKH	59
	60	static int create_timed_output_class(void)
	61	{
	62	if (!timed_output_class) {
	63	timed_output_class = class_create(THIS_MODULE, "timed_output");
	64	if (IS_ERR(timed_output_class))
	65	return PTR_ERR(timed_output_class);
	66	atomic_set(&device_count, 0);
9d3ab801	67	timed_output_class->dev_groups = timed_output_groups;
355b0502 GKH	68	}
	69
	70	return 0;
	71	}
	72
	73	int timed_output_dev_register(struct timed_output_dev *tdev)
	74	{
	75	int ret;
	76
	77	if (!tdev \|\| !tdev->name \|\| !tdev->enable \|\| !tdev->get_time)
	78	return -EINVAL;
	79
	80	ret = create_timed_output_class();
	81	if (ret < 0)
	82	return ret;
	83
	84	tdev->index = atomic_inc_return(&device_count);
	85	tdev->dev = device_create(timed_output_class, NULL,
02aa2a37	86	MKDEV(0, tdev->index), NULL, "%s", tdev->name);
355b0502 GKH	87	if (IS_ERR(tdev->dev))
	88	return PTR_ERR(tdev->dev);
	89
355b0502 GKH	90	dev_set_drvdata(tdev->dev, tdev);
	91	tdev->state = 0;
	92	return 0;
355b0502 GKH	93	}
	94	EXPORT_SYMBOL_GPL(timed_output_dev_register);
	95
	96	void timed_output_dev_unregister(struct timed_output_dev *tdev)
	97	{
d9a861d5	98	tdev->enable(tdev, 0);
355b0502 GKH	99	device_destroy(timed_output_class, MKDEV(0, tdev->index));
	100	dev_set_drvdata(tdev->dev, NULL);
	101	}
	102	EXPORT_SYMBOL_GPL(timed_output_dev_unregister);
	103
	104	static int __init timed_output_init(void)
	105	{
	106	return create_timed_output_class();
	107	}
	108
	109	static void __exit timed_output_exit(void)
	110	{
	111	class_destroy(timed_output_class);
	112	}
	113
	114	module_init(timed_output_init);
	115	module_exit(timed_output_exit);
	116
	117	MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
	118	MODULE_DESCRIPTION("timed output class driver");
	119	MODULE_LICENSE("GPL");