/* drivers/i2c/chips/akm8973.c - akm8973 compass driver
 *
 * Copyright (C) 2008-2009 HTC Corporation.
 *
 * 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/interrupt.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/miscdevice.h>
#include <asm/gpio.h>
#include <asm/uaccess.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/freezer.h>
#include <linux/akm8973.h>
#include<linux/earlysuspend.h>

#define DEBUG 0
#define MAX_FAILURE_COUNT 3

static struct i2c_client *this_client;

struct akm8973_data {
	struct input_dev *input_dev;
	struct work_struct work;
	struct early_suspend early_suspend_akm;
};

/* Addresses to scan -- protected by sense_data_mutex */
static char sense_data[RBUFF_SIZE + 1];
static struct mutex sense_data_mutex;
#define AKM8973_RETRY_COUNT 10
static DECLARE_WAIT_QUEUE_HEAD(data_ready_wq);
static DECLARE_WAIT_QUEUE_HEAD(open_wq);

static atomic_t data_ready;
static atomic_t open_count;
static atomic_t open_flag;
static atomic_t reserve_open_flag;

static atomic_t m_flag;
static atomic_t a_flag;
static atomic_t t_flag;
static atomic_t mv_flag;

static int failure_count = 0;

static short akmd_delay = 0;

static atomic_t suspend_flag = ATOMIC_INIT(0);

static struct akm8973_platform_data *pdata;

static int AKI2C_RxData(char *rxData, int length)
{
	uint8_t loop_i;
	struct i2c_msg msgs[] = {
		{
		 .addr = this_client->addr,
		 .flags = 0,
		 .len = 1,
		 .buf = rxData,
		 },
		{
		 .addr = this_client->addr,
		 .flags = I2C_M_RD,
		 .len = length,
		 .buf = rxData,
		 },
	};

	for (loop_i = 0; loop_i < AKM8973_RETRY_COUNT; loop_i++) {
		if (i2c_transfer(this_client->adapter, msgs, 2) > 0) {
			break;
		}
		mdelay(10);
	}

	if (loop_i >= AKM8973_RETRY_COUNT) {
		printk(KERN_ERR "%s retry over %d\n", __func__, AKM8973_RETRY_COUNT);
		return -EIO;
	}
	return 0;
}

static int AKI2C_TxData(char *txData, int length)
{
	uint8_t loop_i;
	struct i2c_msg msg[] = {
		{
		 .addr = this_client->addr,
		 .flags = 0,
		 .len = length,
		 .buf = txData,
		 },
	};

	for (loop_i = 0; loop_i < AKM8973_RETRY_COUNT; loop_i++) {
		if (i2c_transfer(this_client->adapter, msg, 1) > 0) {
			break;
		}
		mdelay(10);
	}

	if (loop_i >= AKM8973_RETRY_COUNT) {
		printk(KERN_ERR "%s retry over %d\n", __func__, AKM8973_RETRY_COUNT);
		return -EIO;
	}
	return 0;
}

static void AKECS_Reset(void)
{
	gpio_set_value(pdata->reset, 0);
	udelay(120);
	gpio_set_value(pdata->reset, 1);
}

static int AKECS_StartMeasure(void)
{
	char buffer[2];

	atomic_set(&data_ready, 0);

	/* Set measure mode */
	buffer[0] = AKECS_REG_MS1;
	buffer[1] = AKECS_MODE_MEASURE;

	/* Set data */
	return AKI2C_TxData(buffer, 2);
}

static int AKECS_PowerDown(void)
{
	char buffer[2];
	int ret;

	/* Set powerdown mode */
	buffer[0] = AKECS_REG_MS1;
	buffer[1] = AKECS_MODE_POWERDOWN;
	/* Set data */
	ret = AKI2C_TxData(buffer, 2);
	if (ret < 0)
		return ret;

	/* Dummy read for clearing INT pin */
	buffer[0] = AKECS_REG_TMPS;
	/* Read data */
	ret = AKI2C_RxData(buffer, 1);
	if (ret < 0)
		return ret;
	return ret;
}

static int AKECS_StartE2PRead(void)
{
	char buffer[2];

	/* Set measure mode */
	buffer[0] = AKECS_REG_MS1;
	buffer[1] = AKECS_MODE_E2P_READ;
	/* Set data */
	return AKI2C_TxData(buffer, 2);
}

static int AKECS_GetData(void)
{
	char buffer[RBUFF_SIZE + 1];
	int ret;

	memset(buffer, 0, RBUFF_SIZE + 1);
	buffer[0] = AKECS_REG_ST;
	ret = AKI2C_RxData(buffer, RBUFF_SIZE+1);
	if (ret < 0)
		return ret;

	mutex_lock(&sense_data_mutex);
	memcpy(sense_data, buffer, sizeof(buffer));
	atomic_set(&data_ready, 1);
	wake_up(&data_ready_wq);
	mutex_unlock(&sense_data_mutex);

	return 0;
}

static int AKECS_SetMode(char mode)
{
	int ret;

	switch (mode) {
	case AKECS_MODE_MEASURE:
		ret = AKECS_StartMeasure();
		break;
	case AKECS_MODE_E2P_READ:
		ret = AKECS_StartE2PRead();
		break;
	case AKECS_MODE_POWERDOWN:
		ret = AKECS_PowerDown();
		break;
	default:
		return -EINVAL;
	}

	/* wait at least 300us after changing mode */
	mdelay(1);
	return ret;
}

static int AKECS_TransRBuff(char *rbuf, int size)
{
	wait_event_interruptible_timeout(data_ready_wq,
					 atomic_read(&data_ready), 1000);
	if (!atomic_read(&data_ready)) {
		if (!atomic_read(&suspend_flag)) {
			printk(KERN_ERR
				"AKM8973 AKECS_TransRBUFF: Data not ready\n");
			failure_count++;
			if (failure_count >= MAX_FAILURE_COUNT) {
				printk(KERN_ERR
				       "AKM8973 AKECS_TransRBUFF: successive %d failure.\n",
				       failure_count);
				atomic_set(&open_flag, -1);
				wake_up(&open_wq);
				failure_count = 0;
			}
		}
		return -1;
	}

	mutex_lock(&sense_data_mutex);
	memcpy(&rbuf[1], &sense_data[1], size);
	atomic_set(&data_ready, 0);
	mutex_unlock(&sense_data_mutex);

	failure_count = 0;
	return 0;
}


static void AKECS_Report_Value(short *rbuf)
{
	struct akm8973_data *data = i2c_get_clientdata(this_client);
#if DEBUG
	printk(KERN_INFO"AKECS_Report_Value: yaw = %d, pitch = %d, roll = %d\n", rbuf[0],
	       rbuf[1], rbuf[2]);
	printk(KERN_INFO"                    tmp = %d, m_stat= %d, g_stat=%d\n", rbuf[3],
	       rbuf[4], rbuf[5]);
	printk(KERN_INFO"          G_Sensor:   x = %d LSB, y = %d LSB, z = %d LSB\n",
	       rbuf[6], rbuf[7], rbuf[8]);
#endif

	/* Offset compass hack taken from michyprimas kernel */
	short valueint = rbuf[0];
	if ((valueint + 85) < 360)
	{
		rbuf[0] = valueint + 85;
	}
	else
	{
		short diff = 359 - valueint;
		rbuf[0] = 85 - diff;
	}

	/* Report magnetic sensor information */
	if (atomic_read(&m_flag)) {
		input_report_abs(data->input_dev, ABS_RX, rbuf[0]);
		input_report_abs(data->input_dev, ABS_RY, rbuf[1]);
		input_report_abs(data->input_dev, ABS_RZ, rbuf[2]);
		input_report_abs(data->input_dev, ABS_RUDDER, rbuf[4]);
	}

	/* Report acceleration sensor information */
	if (atomic_read(&a_flag)) {
		input_report_abs(data->input_dev, ABS_X, rbuf[6]);
		input_report_abs(data->input_dev, ABS_Y, rbuf[7]);
		input_report_abs(data->input_dev, ABS_Z, rbuf[8]);
		input_report_abs(data->input_dev, ABS_WHEEL, rbuf[5]);
	}

	/* Report temperature information */
	if (atomic_read(&t_flag))
		input_report_abs(data->input_dev, ABS_THROTTLE, rbuf[3]);

	if (atomic_read(&mv_flag)) {
		input_report_abs(data->input_dev, ABS_HAT0X, rbuf[9]);
		input_report_abs(data->input_dev, ABS_HAT0Y, rbuf[10]);
		input_report_abs(data->input_dev, ABS_BRAKE, rbuf[11]);
	}

	input_sync(data->input_dev);
}

static int AKECS_GetOpenStatus(void)
{
	wait_event_interruptible(open_wq, (atomic_read(&open_flag) != 0));
	return atomic_read(&open_flag);
}

static int AKECS_GetCloseStatus(void)
{
	wait_event_interruptible(open_wq, (atomic_read(&open_flag) <= 0));
	return atomic_read(&open_flag);
}

static void AKECS_CloseDone(void)
{
	atomic_set(&m_flag, 0);
	atomic_set(&a_flag, 0);
	atomic_set(&t_flag, 0);
	atomic_set(&mv_flag, 0);
}

static int akm_aot_open(struct inode *inode, struct file *file)
{
	int ret = -1;
	if (atomic_cmpxchg(&open_count, 0, 1) == 0) {
		if (atomic_cmpxchg(&open_flag, 0, 1) == 0) {
			atomic_set(&reserve_open_flag, 1);
			wake_up(&open_wq);
			ret = 0;
		}
	}
	return ret;
}

static int akm_aot_release(struct inode *inode, struct file *file)
{
	atomic_set(&reserve_open_flag, 0);
	atomic_set(&open_flag, 0);
	atomic_set(&open_count, 0);
	wake_up(&open_wq);
	return 0;
}

static int
akm_aot_ioctl(struct inode *inode, struct file *file,
	      unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	short flag;

	switch (cmd) {
	case ECS_IOCTL_APP_SET_MFLAG:
	case ECS_IOCTL_APP_SET_AFLAG:
	case ECS_IOCTL_APP_SET_TFLAG:
	case ECS_IOCTL_APP_SET_MVFLAG:
		if (copy_from_user(&flag, argp, sizeof(flag)))
			return -EFAULT;
		if (flag < 0 || flag > 1)
			return -EINVAL;
		break;
	case ECS_IOCTL_APP_SET_DELAY:
		if (copy_from_user(&flag, argp, sizeof(flag)))
			return -EFAULT;
		break;
	default:
		break;
	}

	switch (cmd) {
	case ECS_IOCTL_APP_SET_MFLAG:
		atomic_set(&m_flag, flag);
		break;
	case ECS_IOCTL_APP_GET_MFLAG:
		flag = atomic_read(&m_flag);
		break;
	case ECS_IOCTL_APP_SET_AFLAG:
		atomic_set(&a_flag, flag);
		break;
	case ECS_IOCTL_APP_GET_AFLAG:
		flag = atomic_read(&a_flag);
		break;
	case ECS_IOCTL_APP_SET_TFLAG:
		atomic_set(&t_flag, flag);
		break;
	case ECS_IOCTL_APP_GET_TFLAG:
		flag = atomic_read(&t_flag);
		break;
	case ECS_IOCTL_APP_SET_MVFLAG:
		atomic_set(&mv_flag, flag);
		break;
	case ECS_IOCTL_APP_GET_MVFLAG:
		flag = atomic_read(&mv_flag);
		break;
	case ECS_IOCTL_APP_SET_DELAY:
		akmd_delay = flag;
		break;
	case ECS_IOCTL_APP_GET_DELAY:
		flag = akmd_delay;
		break;
	default:
		return -ENOTTY;
	}

	switch (cmd) {
	case ECS_IOCTL_APP_GET_MFLAG:
	case ECS_IOCTL_APP_GET_AFLAG:
	case ECS_IOCTL_APP_GET_TFLAG:
	case ECS_IOCTL_APP_GET_MVFLAG:
	case ECS_IOCTL_APP_GET_DELAY:
		if (copy_to_user(argp, &flag, sizeof(flag)))
			return -EFAULT;
		break;
	default:
		break;
	}

	return 0;
}

static int akmd_open(struct inode *inode, struct file *file)
{
	return nonseekable_open(inode, file);
}

static int akmd_release(struct inode *inode, struct file *file)
{
	AKECS_CloseDone();
	return 0;
}

static int
akmd_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	   unsigned long arg)
{

	void __user *argp = (void __user *)arg;

	char msg[RBUFF_SIZE + 1], rwbuf[5];
	int ret = -1, status;
	short mode, value[12], delay;
	char project_name[64];
	short layouts[4][3][3];
	int i, j, k;


	switch (cmd) {
	case ECS_IOCTL_WRITE:
	case ECS_IOCTL_READ:
		if (copy_from_user(&rwbuf, argp, sizeof(rwbuf)))
			return -EFAULT;
		break;
	case ECS_IOCTL_SET_MODE:
		if (copy_from_user(&mode, argp, sizeof(mode)))
			return -EFAULT;
		break;
	case ECS_IOCTL_SET_YPR:
		if (copy_from_user(&value, argp, sizeof(value)))
			return -EFAULT;
		break;
	default:
		break;
	}

	switch (cmd) {
	case ECS_IOCTL_WRITE:
		if (rwbuf[0] < 2)
			return -EINVAL;
		ret = AKI2C_TxData(&rwbuf[1], rwbuf[0]);
		if (ret < 0)
			return ret;
		break;
	case ECS_IOCTL_READ:
		if (rwbuf[0] < 1)
			return -EINVAL;
		ret = AKI2C_RxData(&rwbuf[1], rwbuf[0]);
		if (ret < 0)
			return ret;
		break;
	case ECS_IOCTL_RESET:
		AKECS_Reset();
		break;
	case ECS_IOCTL_SET_MODE:
		ret = AKECS_SetMode((char)mode);
		if (ret < 0)
			return ret;
		break;
	case ECS_IOCTL_GETDATA:
		ret = AKECS_TransRBuff(msg, RBUFF_SIZE);
		if (ret < 0)
			return ret;
		break;
	case ECS_IOCTL_SET_YPR:
		AKECS_Report_Value(value);
		break;
	case ECS_IOCTL_GET_OPEN_STATUS:
		status = AKECS_GetOpenStatus();
		break;
	case ECS_IOCTL_GET_CLOSE_STATUS:
		status = AKECS_GetCloseStatus();
		break;
	case ECS_IOCTL_GET_DELAY:
		delay = akmd_delay;
		break;
	case ECS_IOCTL_GET_PROJECT_NAME:
		strncpy(project_name, pdata->project_name, 64);
		break;
	case ECS_IOCTL_GET_MATRIX:
		for (i = 0; i < 4; i++)
			for (j = 0; j < 3; j++)
				for (k = 0; k < 3; k++)
					layouts[i][j][k] =
						pdata->layouts[i][j][k];
		break;
	default:
		return -ENOTTY;
	}

	switch (cmd) {
	case ECS_IOCTL_READ:
		if (copy_to_user(argp, &rwbuf, sizeof(rwbuf)))
			return -EFAULT;
		break;
	case ECS_IOCTL_GETDATA:
		if (copy_to_user(argp, &msg, sizeof(msg)))
			return -EFAULT;
		break;
	case ECS_IOCTL_GET_OPEN_STATUS:
	case ECS_IOCTL_GET_CLOSE_STATUS:
		if (copy_to_user(argp, &status, sizeof(status)))
			return -EFAULT;
		break;
	case ECS_IOCTL_GET_DELAY:
		if (copy_to_user(argp, &delay, sizeof(delay)))
			return -EFAULT;
		break;
	case ECS_IOCTL_GET_PROJECT_NAME:
		if (copy_to_user(argp, project_name, sizeof(project_name)))
			return -EFAULT;
		break;
	case ECS_IOCTL_GET_MATRIX:
		if (copy_to_user(argp, layouts, sizeof(layouts)))
			return -EFAULT;
		break;
	default:
		break;
	}

	return 0;
}

static void akm_work_func(struct work_struct *work)
{
	if (AKECS_GetData() < 0)
		printk(KERN_ERR "AKM8973 akm_work_func: Get data failed\n");
	enable_irq(this_client->irq);
}

static irqreturn_t akm8973_interrupt(int irq, void *dev_id)
{
	struct akm8973_data *data = dev_id;
	disable_irq_nosync(this_client->irq);
	schedule_work(&data->work);
	return IRQ_HANDLED;
}

static void akm8973_early_suspend(struct early_suspend *handler)
{
	atomic_set(&suspend_flag, 1);
	atomic_set(&reserve_open_flag, atomic_read(&open_flag));
	atomic_set(&open_flag, 0);
	wake_up(&open_wq);
	disable_irq(this_client->irq);
}

static void akm8973_early_resume(struct early_suspend *handler)
{
	enable_irq(this_client->irq);
	atomic_set(&suspend_flag, 0);
	atomic_set(&open_flag, atomic_read(&reserve_open_flag));
	wake_up(&open_wq);
}

static struct file_operations akmd_fops = {
	.owner = THIS_MODULE,
	.open = akmd_open,
	.release = akmd_release,
	.ioctl = akmd_ioctl,
};

static struct file_operations akm_aot_fops = {
	.owner = THIS_MODULE,
	.open = akm_aot_open,
	.release = akm_aot_release,
	.ioctl = akm_aot_ioctl,
};


static struct miscdevice akm_aot_device = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "akm8973_aot",
	.fops = &akm_aot_fops,
};


static struct miscdevice akmd_device = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "akm8973_daemon",
	.fops = &akmd_fops,
};

int akm8973_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct akm8973_data *akm;
	int err = 0;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		err = -ENODEV;
		goto exit_check_functionality_failed;
	}

	akm = kzalloc(sizeof(struct akm8973_data), GFP_KERNEL);
	if (!akm) {
		err = -ENOMEM;
		goto exit_alloc_data_failed;
	}

	INIT_WORK(&akm->work, akm_work_func);
	i2c_set_clientdata(client, akm);

	pdata = client->dev.platform_data;
	if (pdata == NULL) {
		printk(KERN_ERR"AKM8973 akm8973_probe: platform data is NULL\n");
		goto exit_platform_data_null;
	}
	this_client = client;

	if (pdata && pdata->reset) {
		err = gpio_request(pdata->reset, "akm8973");
		if (err < 0) {
			printk(KERN_ERR "%s: request reset gpio failed\n",
				__func__);
			goto err_request_reset_gpio;
		}
		err = gpio_direction_output(pdata->reset, 1);
		if (err < 0) {
			printk(KERN_ERR
				"%s: request reset gpio failed\n", __func__);
			goto err_set_reset_gpio;
		}
	} else {
		printk(KERN_ERR "%s: pdata or pdata->reset is NULL\n",
			__func__);
		goto err_request_reset_gpio;
	}

	err = AKECS_PowerDown();
	if (err < 0) {
		printk(KERN_ERR"AKM8973 akm8973_probe: set power down mode error\n");
		goto exit_set_mode_failed;
	}

	err = request_irq(client->irq, akm8973_interrupt, IRQF_TRIGGER_HIGH,
			  "akm8973", akm);

	if (err < 0) {
		printk(KERN_ERR"AKM8973 akm8973_probe: request irq failed\n");
		goto exit_irq_request_failed;
	}

	akm->input_dev = input_allocate_device();

	if (!akm->input_dev) {
		err = -ENOMEM;
		printk(KERN_ERR
		       "AKM8973 akm8973_probe: Failed to allocate input device\n");
		goto exit_input_dev_alloc_failed;
	}

	set_bit(EV_ABS, akm->input_dev->evbit);
	/* yaw */
	input_set_abs_params(akm->input_dev, ABS_RX, 0, 360, 0, 0);
	/* pitch */
	input_set_abs_params(akm->input_dev, ABS_RY, -180, 180, 0, 0);
	/* roll */
	input_set_abs_params(akm->input_dev, ABS_RZ, -90, 90, 0, 0);
	/* x-axis acceleration */
	input_set_abs_params(akm->input_dev, ABS_X, -1872, 1872, 0, 0);
	/* y-axis acceleration */
	input_set_abs_params(akm->input_dev, ABS_Y, -1872, 1872, 0, 0);
	/* z-axis acceleration */
	input_set_abs_params(akm->input_dev, ABS_Z, -1872, 1872, 0, 0);
	/* temparature */
	input_set_abs_params(akm->input_dev, ABS_THROTTLE, -30, 85, 0, 0);
	/* status of magnetic sensor */
	input_set_abs_params(akm->input_dev, ABS_RUDDER, -32768, 3, 0, 0);
	/* status of acceleration sensor */
	input_set_abs_params(akm->input_dev, ABS_WHEEL, -32768, 3, 0, 0);
	/* step count */
	input_set_abs_params(akm->input_dev, ABS_GAS, 0, 65535, 0, 0);
	/* x-axis of raw magnetic vector */
	input_set_abs_params(akm->input_dev, ABS_HAT0X, -2048, 2032, 0, 0);
	/* y-axis of raw magnetic vector */
	input_set_abs_params(akm->input_dev, ABS_HAT0Y, -2048, 2032, 0, 0);
	/* z-axis of raw magnetic vector */
	input_set_abs_params(akm->input_dev, ABS_BRAKE, -2048, 2032, 0, 0);

	akm->input_dev->name = "compass";

	err = input_register_device(akm->input_dev);

	if (err) {
		printk(KERN_ERR
		       "AKM8973 akm8973_probe: Unable to register input device: %s\n",
		       akm->input_dev->name);
		goto exit_input_register_device_failed;
	}

	err = misc_register(&akmd_device);
	if (err) {
		printk(KERN_ERR "AKM8973 akm8973_probe: akmd_device register failed\n");
		goto exit_misc_device_register_failed;
	}

	err = misc_register(&akm_aot_device);
	if (err) {
		printk(KERN_ERR
		       "AKM8973 akm8973_probe: akm_aot_device register failed\n");
		goto exit_misc_device_register_failed;
	}

	mutex_init(&sense_data_mutex);

	init_waitqueue_head(&data_ready_wq);
	init_waitqueue_head(&open_wq);

	/* As default, do not report all information */
	atomic_set(&m_flag, 0);
	atomic_set(&a_flag, 0);
	atomic_set(&t_flag, 0);
	atomic_set(&mv_flag, 0);

	akm->early_suspend_akm.suspend = akm8973_early_suspend;
	akm->early_suspend_akm.resume = akm8973_early_resume;
	register_early_suspend(&akm->early_suspend_akm);

	return 0;

exit_misc_device_register_failed:
exit_input_register_device_failed:
	input_free_device(akm->input_dev);
exit_input_dev_alloc_failed:
	free_irq(client->irq, akm);
exit_irq_request_failed:
exit_set_mode_failed:
err_set_reset_gpio:
	gpio_free(pdata->reset);
err_request_reset_gpio:
exit_platform_data_null:
	kfree(akm);
exit_alloc_data_failed:
exit_check_functionality_failed:
	return err;

}

static int akm8973_remove(struct i2c_client *client)
{
	struct akm8973_data *akm = i2c_get_clientdata(client);
	free_irq(client->irq, akm);
	input_unregister_device(akm->input_dev);
	kfree(akm);
	if (pdata && pdata->reset)
		gpio_free(pdata->reset);
	return 0;
}
static const struct i2c_device_id akm8973_id[] = {
	{ AKM8973_I2C_NAME, 0 },
	{ }
};

static struct i2c_driver akm8973_driver = {
	.probe 	= akm8973_probe,
	.remove 	= akm8973_remove,
	.id_table	= akm8973_id,
	.driver = {
		   .name = AKM8973_I2C_NAME,
		   },
};

static int __init akm8973_init(void)
{
	printk(KERN_INFO "AKM8973 compass driver: init\n");
	return i2c_add_driver(&akm8973_driver);
}

static void __exit akm8973_exit(void)
{
	i2c_del_driver(&akm8973_driver);
}

module_init(akm8973_init);
module_exit(akm8973_exit);

MODULE_AUTHOR("viral wang <viral_wang@htc.com>");
MODULE_DESCRIPTION("AKM8973 compass driver");
MODULE_LICENSE("GPL");