/*
 *  Universal sensors core class
 *
 *  Author : Ryunkyun Park <ryun.park@samsung.com>
 */

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

struct class *sensors_class;
EXPORT_SYMBOL_GPL(sensors_class);
struct class *sensors_event_class;
EXPORT_SYMBOL_GPL(sensors_event_class);
static atomic_t sensor_count;
static struct device *symlink_dev;

/*
 * Create sysfs interface
 */
static void set_sensor_attr(struct device *dev,
	struct device_attribute *attributes[])
{
	int i;

	for (i = 0; attributes[i] != NULL; i++)
		if ((device_create_file(dev, attributes[i])) < 0)
			pr_err("[SENSOR CORE] fail device_create_file"\
				"(dev, attributes[%d])\n", i);
}

int sensors_create_symlink(struct input_dev *inputdev)
{
	int err = 0;

	if (symlink_dev == NULL) {
		pr_err("%s, symlink_dev is NULL!!!\n", __func__);
		return err ;
	}

	err = sysfs_create_link(&symlink_dev->kobj, &inputdev->dev.kobj, inputdev->name);

	if (err < 0) {
		pr_err("%s, %s failed!(%d)\n", __func__, inputdev->name, err);
		return err;
	}

	return err;
}
EXPORT_SYMBOL_GPL(sensors_create_symlink);

void sensors_remove_symlink(struct input_dev *inputdev)
{

	if (symlink_dev == NULL) {
		pr_err("%s, symlink_dev is NULL!!!\n", __func__);
		return;
	}

	sysfs_delete_link(&symlink_dev->kobj, &inputdev->dev.kobj, inputdev->name);
}
EXPORT_SYMBOL_GPL(sensors_remove_symlink);


int sensors_register(struct device *dev, void *drvdata,
	struct device_attribute *attributes[], char *name)
{
	int ret = 0;

	if (!sensors_class) {
		sensors_class = class_create(THIS_MODULE, "sensors");
		if (IS_ERR(sensors_class))
			return PTR_ERR(sensors_class);
	}

	dev = device_create(sensors_class, NULL, 0, drvdata, "%s", name);

	if (IS_ERR(dev)) {
		ret = PTR_ERR(dev);
		pr_err("[SENSORS CORE] device_create failed!"\
			"[%d]\n", ret);
		return ret;
	}

	set_sensor_attr(dev, attributes);
	atomic_inc(&sensor_count);

	return 0;
}
EXPORT_SYMBOL_GPL(sensors_register);

void sensors_unregister(struct device *dev,
	struct device_attribute *attributes[])
{
	int i;

	for (i = 0; attributes[i] != NULL; i++)
		device_remove_file(dev, attributes[i]);
}
EXPORT_SYMBOL_GPL(sensors_unregister);

void destroy_sensor_class(void)
{
	if (sensors_class) {
		class_destroy(sensors_class);
		sensors_class = NULL;
	}

	if (sensors_event_class) {
		device_destroy(sensors_event_class, symlink_dev->devt);
		class_destroy(sensors_event_class);
		symlink_dev = NULL;
		sensors_event_class = NULL;
	}
}
EXPORT_SYMBOL_GPL(destroy_sensor_class);

static int __init sensors_class_init(void)
{
	pr_info("[SENSORS CORE] sensors_class_init\n");
	sensors_class = class_create(THIS_MODULE, "sensors");

	if (IS_ERR(sensors_class)) {
		pr_err("%s, create sensors_class is failed.(err=%ld)\n",
			__func__, IS_ERR(sensors_class));
		return PTR_ERR(sensors_class);
	}

	/* For symbolic link */
	sensors_event_class = class_create(THIS_MODULE, "sensor_event");
	if (IS_ERR(sensors_event_class)) {
		pr_err("%s, create sensors_class is failed.(err=%ld)\n",
			__func__, IS_ERR(sensors_event_class));
		return PTR_ERR(sensors_event_class);
	}

	symlink_dev = device_create(sensors_event_class, NULL, 0, NULL,
		"%s", "symlink");

	if (IS_ERR(symlink_dev)) {
		pr_err("[SENSORS CORE] symlink_dev create failed!"\
			"[%ld]\n", IS_ERR(symlink_dev));
		return PTR_ERR(symlink_dev);
	}

	atomic_set(&sensor_count, 0);
	sensors_class->dev_uevent = NULL;
	pr_info("[SENSORS CORE] sensors_class_init succcess\n");

	return 0;
}

static void __exit sensors_class_exit(void)
{
	if (sensors_class || sensors_event_class) {
		class_destroy(sensors_class);
		sensors_class = NULL;
		class_destroy(sensors_event_class);
		sensors_event_class = NULL;
	}
}

subsys_initcall(sensors_class_init);
module_exit(sensors_class_exit);

MODULE_DESCRIPTION("Universal sensors core class");
MODULE_AUTHOR("Ryunkyun Park <ryun.park@samsung.com>");
MODULE_LICENSE("GPL");