/*
 * drivers/barcelona/gps/gps.c
 *
 * Implementation of the GPS driver.
 *
 * Copyright (C) 2004,2005 TomTom BV <http://www.tomtom.com/>
 * Authors:
 * Jeroen Taverne <jeroen.taverne@tomtom.com>
 * Dimitry Andric <dimitry.andric@tomtom.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/*******************************************************************************
* Dependency
*******************************************************************************/
#ifdef CONFIG_MTK_GPS_SUPPORT
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/cdev.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
/* #include <linux/xlog.h> */
#include <linux/printk.h>
#include <linux/semaphore.h>
#include <linux/version.h>

#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) "["KBUILD_MODNAME"]" fmt

/******************************************************************************
 * Function Configuration
******************************************************************************/
/* #define FAKE_DATA */
#define GPS_SUSPEND_RESUME
#define GPS_CONFIGURABLE_RESET_DELAY
/******************************************************************************
 * Definition
******************************************************************************/
/* device name and major number */
#define GPS_DEVNAME            "mt3326-gps"
/******************************************************************************
 * Debug configuration
******************************************************************************/
#if 0
#define GPS_DBG_FUNC(fmt, arg...)    pr_debug(PFX, "%s: " fmt, __func__ , ##arg)
#define GPS_ERR(fmt, arg...)         pr_err(PFX, "%s: " fmt, __func__ , ##arg)
#define GPS_WARN(fmt, arg...)        pr_warn(PFX, "%s" fmt, __func__ , ##arg)
#define GPS_NOTICE(fmt, arg...)      pr_notice(PFX, "%s: " fmt, __func__ , ##arg)
#define GPS_INFO(fmt, arg...)        pr_info(PFX, "%s: " fmt, __func__ , ##arg)
#define PFX "GPS: "
#else
#define GPS_DBG_NONE(fmt, arg...)    do {} while (0)
#define GPS_DBG pr_debug
#define GPS_TRC GPS_DBG_NONE
#define GPS_VER pr_debug
#define GPS_ERR pr_err
#endif
/*******************************************************************************
* structure & enumeration
*******************************************************************************/
enum {
	GPS_PWRCTL_UNSUPPORTED = 0xFF,
	GPS_PWRCTL_OFF = 0x00,
	GPS_PWRCTL_ON = 0x01,
	GPS_PWRCTL_RST = 0x02,
	GPS_PWRCTL_OFF_FORCE = 0x03,
	GPS_PWRCTL_RST_FORCE = 0x04,
	GPS_PWRCTL_MAX = 0x05,
};
enum {
	GPS_PWR_UNSUPPORTED = 0xFF,
	GPS_PWR_RESUME = 0x00,
	GPS_PWR_SUSPEND = 0x01,
	GPS_PWR_MAX = 0x02,
};
enum {
	GPS_STATE_UNSUPPORTED = 0xFF,
	GPS_STATE_OFF = 0x00,	/*cleanup/power off, default state */
	GPS_STATE_INIT = 0x01,	/*init */
	GPS_STATE_START = 0x02,	/*start navigating */
	GPS_STATE_STOP = 0x03,	/*stop navigating */
	GPS_STATE_DEC_FREQ = 0x04,
	GPS_STATE_SLEEP = 0x05,
	GPS_STATE_MAX = 0x06,
};
enum {
	GPS_PWRSAVE_UNSUPPORTED = 0xFF,
	GPS_PWRSAVE_DEC_FREQ = 0x00,
	GPS_PWRSAVE_SLEEP = 0x01,
	GPS_PWRSAVE_OFF = 0x02,
	GPS_PWRSAVE_MAX = 0x03,
};
/*---------------------------------------------------------------------------*/
struct gps_data {
	int dat_len;
	int dat_pos;
	char dat_buf[4096];
	spinlock_t lock;
	wait_queue_head_t read_wait;
	struct semaphore sem;
};
/*---------------------------------------------------------------------------*/
struct gps_sta_itm {		/*gps status record */
	unsigned char year;	/*current year - 1900 */
	unsigned char month;	/*1~12 */
	unsigned char day;	/*1~31 */
	unsigned char hour;	/*0~23 */

	unsigned char minute;	/*0~59 */
	unsigned char sec;	/*0~59 */
	unsigned char count;	/*reborn count */
	unsigned char reason;	/*reason: 0: timeout; 1: force */
};
/*---------------------------------------------------------------------------*/
struct gps_sta_obj {
	int index;
	struct gps_sta_itm items[32];
};
/*---------------------------------------------------------------------------*/
struct gps_drv_obj {
	unsigned char pwrctl;
	unsigned char suspend;
	unsigned char state;
	unsigned char pwrsave;
	int rdelay;		/*power reset delay */
	struct kobject *kobj;
	struct mutex sem;
	struct gps_sta_obj status;
	struct mt3326_gps_hardware *hw;
};
/*---------------------------------------------------------------------------*/
struct gps_dev_obj {
	struct class *cls;
	struct device *dev;
	dev_t devno;
	struct cdev chdev;
	struct mt3326_gps_hardware *hw;
};
/******************************************************************************
 * GPS driver
******************************************************************************/
struct mt3326_gps_hardware {
	int (*ext_power_on)(int);
	int (*ext_power_off)(int);
};

struct mt3326_gps_hardware mt3326_gps_hw = {
	.ext_power_on =  NULL,
	.ext_power_off = NULL,
};
/******************************************************************************
 * local variables
******************************************************************************/
static struct gps_data gps_private = { 0 };

#if defined(FAKE_DATA)
static char fake_data[] = {
	"$GPGGA,135036.000,2446.3713,N,12101.3605,E,1,5,1.61,191.1,M,15.1,M,,*51\r\n"
	    "$GPGSA,A,3,22,18,14,30,31,,,,,,,,1.88,1.61,0.98*09\r\n"
	    "$GPGSV,2,1,6,18,83,106,32,22,58,324,35,30,45,157,35,14,28,308,32*44\r\n"
	    "$GPGSV,2,2,6,40,21,254,,31,17,237,29*42\r\n"
	    "$GPRMC,135036.000,A,2446.37125,N,12101.36054,E,0.243,56.48,140109,,A*46\r\n"
	    "$GPVTG,56.48,T,,M,0.243,N,0.451,K,A*07\r\n"
};
#endif /* FAKE_DATA */

/*this should be synchronous with mnld.c
enum {
    MNL_RESTART_NONE            = 0x00, //recording the 1st of mnld
    MNL_RESTART_TIMEOUT_INIT    = 0x01, //restart due to timeout
    MNL_RESTART_TIMEOUT_MONITOR = 0x02, //restart due to timeout
    MNL_RESTART_TIMEOUT_WAKEUP  = 0x03, //restart due to timeout
    MNL_RESTART_TIMEOUT_TTFF    = 0x04, //restart due to TTFF timeout
    MNL_RESTART_FORCE           = 0x04, //restart due to external command
};
*/
/*---------------------------------------------------------------------------*/
static char *str_reason[] = { "none", "init", "monitor", "wakeup", "TTFF", "force", "unknown" };

/******************************************************************************
 * Functions
******************************************************************************/
static inline void mt3326_gps_power(struct mt3326_gps_hardware *hw, unsigned int on, unsigned int force)
{
	/*FIX ME: PM_api should provide a function to get current status */
	static unsigned int power_on = 1;
	int err;

	GPS_DBG("Switching GPS device %s\n", on ? "on" : "off");
	if (!hw) {
		GPS_ERR("null pointer!!\n");
		return;
	}

	if (power_on == on) {
		GPS_DBG("ignore power control: %d\n", on);
	} else if (on) {
		/*power on */
		if (hw->ext_power_on) {
			err = hw->ext_power_on(0);
			if (err)
				GPS_ERR("ext_power_on fail\n");
		}
#if 0
#ifndef MTK_MT6620
		if (!hwPowerOn(MT6516_POWER_V3GTX, VOL_2800, "MT3326")) {
			GPS_ERR("power on fails!!\n");
			return;
		}
#endif
#endif
		if (hw->ext_power_on) {
			err = hw->ext_power_on(1);
			if (err)
				GPS_ERR("ext_power_on fail\n");
		}
#if 0
		if (!hwEnableClock(MT6516_PDN_PERI_UART2, "MT3326"))
			GPS_ERR("enable clock fail");
#endif
		mdelay(120);
	} else {
#if 0
		if (!hwDisableClock(MT6516_PDN_PERI_UART2, "MT3326"))
			GPS_ERR("disable clock fail\n");
#endif
		if (hw->ext_power_off) {
			err = hw->ext_power_off(force);
			if (err)
				GPS_ERR("ext_power_off fail\n");
		}
	}
	power_on = on;
}

/*****************************************************************************/
static inline void mt3326_gps_reset(struct mt3326_gps_hardware *hw, int delay, int force)
{
	mt3326_gps_power(hw, 1, 0);
	mdelay(delay);
	mt3326_gps_power(hw, 0, force);
	mdelay(delay);
	mt3326_gps_power(hw, 1, 0);
}

/******************************************************************************/
static inline int mt3326_gps_set_suspend(struct gps_drv_obj *obj, unsigned char suspend)
{
	if (!obj)
		return -1;
	mutex_lock(&obj->sem);
	if (obj->suspend != suspend) {
		/* GPS_DBG("issue sysfs_notify : %p\n", obj->kobj->sd); */
		sysfs_notify(obj->kobj, NULL, "suspend");
	}
	obj->suspend = suspend;
	mutex_unlock(&obj->sem);
	return 0;
}

/******************************************************************************/
static inline int mt3326_gps_set_pwrctl(struct gps_drv_obj *obj, unsigned char pwrctl)
{
	int err = 0;

	if (!obj)
		return -1;
	mutex_lock(&obj->sem);

	if ((pwrctl == GPS_PWRCTL_ON) || (pwrctl == GPS_PWRCTL_OFF)) {
		obj->pwrctl = pwrctl;
		mt3326_gps_power(obj->hw, pwrctl, 0);
	} else if (pwrctl == GPS_PWRCTL_OFF_FORCE) {
		obj->pwrctl = pwrctl;
		mt3326_gps_power(obj->hw, pwrctl, 1);
	} else if (pwrctl == GPS_PWRCTL_RST) {
		mt3326_gps_reset(obj->hw, obj->rdelay, 0);
		obj->pwrctl = GPS_PWRCTL_ON;
	} else if (pwrctl == GPS_PWRCTL_RST_FORCE) {
		mt3326_gps_reset(obj->hw, obj->rdelay, 1);
		obj->pwrctl = GPS_PWRCTL_ON;
	} else {
		err = -1;
	}
	mutex_unlock(&obj->sem);
	return err;
}

 /******************************************************************************/
static inline int mt3326_gps_set_status(struct gps_drv_obj *obj, const char *buf, size_t count)
{
	int err = 0;
	int year, mon, day, hour, minute, sec, cnt, reason, idx;

	if (!obj)
		return -1;

	mutex_lock(&obj->sem);
	if (sscanf(buf, "(%d/%d/%d %d:%d:%d) - %d/%d", &year, &mon, &day, &hour, &minute, &sec, &cnt, &reason) == 8) {
		int number = (int)(sizeof(obj->status.items) / sizeof(obj->status.items[0]));

		idx = obj->status.index % number;
		obj->status.items[idx].year = (unsigned char)year;
		obj->status.items[idx].month = (unsigned char)mon;
		obj->status.items[idx].day = (unsigned char)day;
		obj->status.items[idx].hour = (unsigned char)hour;
		obj->status.items[idx].minute = (unsigned char)minute;
		obj->status.items[idx].sec = (unsigned char)sec;
		obj->status.items[idx].count = (unsigned char)cnt;
		obj->status.items[idx].reason = (unsigned char)reason;
		obj->status.index++;
	} else {
		err = -1;
	}
	mutex_unlock(&obj->sem);
	return err;
}

/******************************************************************************/
static inline int mt3326_gps_set_state(struct gps_drv_obj *obj, unsigned char state)
{
	int err = 0;

	if (!obj)
		return -1;
	mutex_lock(&obj->sem);
	if (state < GPS_STATE_MAX)
		obj->state = state;
	else
		err = -1;
	mutex_unlock(&obj->sem);
	return err;
}

/******************************************************************************/
static inline int mt3326_gps_set_pwrsave(struct gps_drv_obj *obj, unsigned char pwrsave)
{
	int err = 0;

	if (!obj)
		return -1;
	mutex_lock(&obj->sem);
	if (pwrsave < GPS_PWRSAVE_MAX)
		obj->pwrsave = pwrsave;
	else
		err = -1;
	mutex_unlock(&obj->sem);
	return err;
}

/******************************************************************************/
static inline int mt3326_gps_dev_suspend(struct gps_drv_obj *obj)
{
#if defined(GPS_SUSPEND_RESUME)
	int err;

	err = mt3326_gps_set_suspend(obj, GPS_PWR_SUSPEND);
	if (err)
		GPS_DBG("set suspend fail: %d\n", err);
	err = mt3326_gps_set_pwrctl(obj, GPS_PWRCTL_OFF);
	if (err)
		GPS_DBG("set pwrctl fail: %d\n", err);
	return err;
#endif
}

/******************************************************************************/
static inline int mt3326_gps_dev_resume(struct gps_drv_obj *obj)
{
#if defined(GPS_SUSPEND_RESUME)
	int err;

	err = mt3326_gps_set_suspend(obj, GPS_PWR_RESUME);
	if (err)
		GPS_DBG("set suspend fail: %d\n", err);
	/*don't power on device automatically */
	return err;
#endif
}

/******************************************************************************/
static ssize_t mt3326_show_pwrctl(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct gps_drv_obj *obj;
	ssize_t res;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	res = snprintf(buf, PAGE_SIZE, "%d\n", obj->pwrctl);
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_pwrctl(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	if ((count == 1) || ((count == 2) && (buf[1] == '\n'))) {
		unsigned char pwrctl = buf[0] - '0';

		if (!mt3326_gps_set_pwrctl(obj, pwrctl))
			return count;
	}
/* GPS_DBG("invalid content: '%s', length = %ld\n", buf, count); */
	return count;
}

/******************************************************************************/
static ssize_t mt3326_show_suspend(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct gps_drv_obj *obj;
	ssize_t res;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	res = snprintf(buf, PAGE_SIZE, "%d\n", obj->suspend);
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_suspend(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	if ((count == 1) || ((count == 2) && (buf[1] == '\n'))) {
		unsigned char suspend = buf[0] - '0';

		if (suspend == GPS_PWR_SUSPEND) {
			if (!mt3326_gps_dev_suspend(obj))
				return count;
		} else if (suspend == GPS_PWR_RESUME) {
			if (!mt3326_gps_dev_resume(obj))
				return count;
		}
	}
/* GPS_DBG("invalid content: '%s', length = %d\n", buf, count); */
	return count;
}

/******************************************************************************/
static ssize_t mt3326_show_status(struct device *dev, struct device_attribute *attr, char *buf)
{
	int res, idx, num, left, cnt, len;
	struct gps_drv_obj *obj;
	char *reason = NULL;
	int reason_max = (int)(sizeof(str_reason) / sizeof(str_reason[0]));

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	num = (int)(sizeof(obj->status.items) / sizeof(obj->status.items[0]));
	left = PAGE_SIZE;
	cnt = 0;
	len = 0;
	for (idx = 0; idx < num; idx++) {
		if (obj->status.items[idx].month == 0)
			continue;
		if (obj->status.items[idx].reason >= reason_max)
			reason = str_reason[reason_max - 1];
		else
			reason = str_reason[obj->status.items[idx].reason];
		cnt =
		    snprintf(buf + len, left,
			     "[%d] %.4d/%.2d/%.2d %.2d:%.2d:%.2d - %d, %s\n",
			     idx, obj->status.items[idx].year + 1900,
			     obj->status.items[idx].month,
			     obj->status.items[idx].day,
			     obj->status.items[idx].hour,
			     obj->status.items[idx].minute,
			     obj->status.items[idx].sec, obj->status.items[idx].count, reason);
		left -= cnt;
		len += cnt;
	}
	res = PAGE_SIZE - left;
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_status(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int res = 0;
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	res = mt3326_gps_set_status(obj, buf, count);
	if (!res)
		return count;
	GPS_DBG("invalid content: '%p', length = %zu\n", buf, count);
	return count;
}

/******************************************************************************/
static ssize_t mt3326_show_state(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t res;
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	res = snprintf(buf, PAGE_SIZE, "%d\n", obj->state);
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_state(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	if ((count == 1) || ((count == 2) && (buf[1] == '\n'))) {	/*To Do: dynamic change according to input */
		unsigned char state = buf[0] - '0';

		if (!mt3326_gps_set_state(obj, state))
			return count;
	}
	GPS_DBG("invalid content: '%p', length = %zu\n", buf, count);
	return count;
}

/******************************************************************************/
static ssize_t mt3326_show_pwrsave(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t res;
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	res = snprintf(buf, PAGE_SIZE, "%d\n", obj->pwrsave);
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_pwrsave(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	if ((count == 1) || ((count == 2) && (buf[1] == '\n'))) {
		unsigned char pwrsave = buf[0] - '0';

		if (!mt3326_gps_set_pwrsave(obj, pwrsave))
			return count;
	}
	GPS_DBG("invalid content: '%p', length = %zu\n", buf, count);
	return count;
}

/******************************************************************************/
#if defined(GPS_CONFIGURABLE_RESET_DELAY)
/******************************************************************************/
static ssize_t mt3326_show_rdelay(struct device *dev, struct device_attribute *attr, char *buf)
{
	ssize_t res;
	struct gps_drv_obj *obj;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	mutex_lock(&obj->sem);
	res = snprintf(buf, PAGE_SIZE, "%d\n", obj->rdelay);
	mutex_unlock(&obj->sem);
	return res;
}

/******************************************************************************/
static ssize_t mt3326_store_rdelay(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gps_drv_obj *obj;
	int rdelay;
	unsigned long val;

	if (!dev) {
		GPS_DBG("dev is null!!\n");
		return 0;
	}
	obj = (struct gps_drv_obj *)dev_get_drvdata(dev);
	if (!obj) {
		GPS_DBG("drv data is null!!\n");
		return 0;
	}
	rdelay = (int)kstrtol(buf, 10, &val);
	if (rdelay < 2000) {
		mutex_lock(&obj->sem);
		obj->rdelay = rdelay;
		mutex_unlock(&obj->sem);
		return count;
	}
	GPS_DBG("invalid content: '%p', length = %zu\n", buf, count);
	return count;
}

/******************************************************************************/
#endif
/******************************************************************************/
DEVICE_ATTR(pwrctl, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_pwrctl, mt3326_store_pwrctl);
DEVICE_ATTR(suspend, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_suspend, mt3326_store_suspend);
DEVICE_ATTR(status, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_status, mt3326_store_status);
DEVICE_ATTR(state, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_state, mt3326_store_state);
DEVICE_ATTR(pwrsave, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_pwrsave, mt3326_store_pwrsave);
#if defined(GPS_CONFIGURABLE_RESET_DELAY)
DEVICE_ATTR(rdelay, S_IWUSR | S_IWGRP | S_IRUGO, mt3326_show_rdelay, mt3326_store_rdelay);
#endif
static struct device_attribute *gps_attr_list[] = {
	&dev_attr_pwrctl,
	&dev_attr_suspend,
	&dev_attr_status,
	&dev_attr_state,
	&dev_attr_pwrsave,
#if defined(GPS_CONFIGURABLE_RESET_DELAY)
	&dev_attr_rdelay,
#endif
};

/******************************************************************************/
static int mt3326_gps_create_attr(struct device *dev)
{
	int idx, err = 0;
	int num = (int)(sizeof(gps_attr_list) / sizeof(gps_attr_list[0]));

	if (!dev)
		return -EINVAL;

	GPS_TRC();
	for (idx = 0; idx < num; idx++) {
		err = device_create_file(dev, gps_attr_list[idx]);
		if (err) {
			GPS_DBG("device_create_file (%s) = %d\n", gps_attr_list[idx]->attr.name, err);
			break;
		}
	}

	return err;
}

/******************************************************************************/
static int mt3326_gps_delete_attr(struct device *dev)
{
	int idx, err = 0;
	int num = (int)(sizeof(gps_attr_list) / sizeof(gps_attr_list[0]));

	if (!dev)
		return -EINVAL;

	for (idx = 0; idx < num; idx++)
		device_remove_file(dev, gps_attr_list[idx]);

	return err;
}

/******************************************************************************/
long mt3326_gps_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	GPS_DBG("mt3326_gps_unlocked_ioctl!!\n");
	return -ENOIOCTLCMD;
}

/******************************************************************************/
long mt3326_gps_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	long ret;

	GPS_DBG("mt3326_gps_compat_ioctl!!\n");
	ret = mt3326_gps_unlocked_ioctl(file, cmd, arg);
	return ret;
}

/*****************************************************************************/
static int mt3326_gps_open(struct inode *inode, struct file *file)
{
	GPS_TRC();
	file->private_data = &gps_private;	/* all files share the same buffer */
	return nonseekable_open(inode, file);
}

/*****************************************************************************/
static int mt3326_gps_release(struct inode *inode, struct file *file)
{
	struct gps_data *dev = file->private_data;

	GPS_TRC();

	if (dev)
		file->private_data = NULL;

	return 0;
}

/******************************************************************************/
static ssize_t mt3326_gps_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	struct gps_data *dev = file->private_data;
	ssize_t ret = 0;
	int copy_len = 0;

	GPS_TRC();

	if (!dev)
		return -EINVAL;

	if (signal_pending(current))
		return -ERESTARTSYS;

	if (down_interruptible(&dev->sem))
		return -ERESTARTSYS;

	if (dev->dat_len == 0) {	/*no data to be read */
		up(&dev->sem);
		if (file->f_flags & O_NONBLOCK)	/*non-block mode */
			return -EAGAIN;
		do {		/*block mode */
			ret = wait_event_interruptible(dev->read_wait, (dev->dat_len > 0));
			if (ret == -ERESTARTSYS)
				return -ERESTARTSYS;
		} while (ret == 0);
		if (down_interruptible(&dev->sem))
			return -ERESTARTSYS;
	}

	/*data is available */
	copy_len = (dev->dat_len < (int)count) ? (dev->dat_len) : (int)(count);
	if (copy_to_user(buf, (dev->dat_buf + dev->dat_pos), (unsigned long)copy_len)) {
		ret = -EFAULT;
	} else {
		/* GPS_VER("mt3326_gps_read(%ld,%d,%d) = %d\n", count, dev->dat_pos, dev->dat_len, */
		/* copy_len); */
		if (dev->dat_len > (copy_len + dev->dat_pos)) {
			dev->dat_pos += copy_len;
		} else {
			dev->dat_len = 0;
			dev->dat_pos = 0;
		}
		ret = copy_len;
	}

	up(&dev->sem);
	/* GPS_VER("%s return %ld bytes\n", __func__, ret); */
	return ret;
}

/******************************************************************************/
static ssize_t mt3326_gps_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	struct gps_data *dev = file->private_data;
	ssize_t ret = 0;
	int copy_size = 0;

	GPS_TRC();

	if (!dev)
		return -EINVAL;

	if (!count)		/*no data written */
		return 0;

	if (signal_pending(current))
		return -ERESTARTSYS;

	if (down_interruptible(&dev->sem))
		return -ERESTARTSYS;

	copy_size = (count < 4096) ? count : 4096;
	if (copy_from_user(dev->dat_buf, buf, copy_size)) {
		GPS_DBG("copy_from_user error");
		ret = -EFAULT;
	} else {
		dev->dat_len = count;
		dev->dat_pos = 0;
		ret = count;
	}
	up(&dev->sem);
	wake_up_interruptible(&dev->read_wait);
	GPS_VER("%s: write %d bytes\n", __func__, dev->dat_len);
	return ret;
}

/******************************************************************************/
static unsigned int mt3326_gps_poll(struct file *file, poll_table *wait)
{
	struct gps_data *dev = file->private_data;
	unsigned int mask = 0;

	GPS_TRC();

	if (!dev)
		return 0;

	down(&dev->sem);
	poll_wait(file, &dev->read_wait, wait);
	if (dev->dat_len != 0)	/*readable if data is available */
		mask = (POLLIN | POLLRDNORM) | (POLLOUT | POLLWRNORM);
	else			/*always writable */
		mask = (POLLOUT | POLLWRNORM);
	up(&dev->sem);
	GPS_VER("%s: mask : 0x%X\n", __func__, mask);
	return mask;
}

/*****************************************************************************/
/* Kernel interface */
static const struct file_operations mt3326_gps_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = mt3326_gps_unlocked_ioctl,
	.compat_ioctl = mt3326_gps_compat_ioctl,
	.open = mt3326_gps_open,
	.read = mt3326_gps_read,
	.write = mt3326_gps_write,
	.release = mt3326_gps_release,
	.poll = mt3326_gps_poll,
};

/*****************************************************************************/
static void mt3326_gps_hw_init(struct mt3326_gps_hardware *hw)
{
	mt3326_gps_power(hw, 1, 0);
}

/*****************************************************************************/
static void mt3326_gps_hw_exit(struct mt3326_gps_hardware *hw)
{
	mt3326_gps_power(hw, 0, 0);
}

/*****************************************************************************/
static int mt3326_gps_probe(struct platform_device *dev)
{
	int ret = 0, err = 0;
	struct gps_drv_obj *drvobj = NULL;
	/* struct mt3326_gps_hardware *hw = (struct mt3326_gps_hardware *)dev->dev.platform_data; */
	struct mt3326_gps_hardware *hw = &mt3326_gps_hw;
	struct gps_dev_obj *devobj = NULL;

	devobj = kzalloc(sizeof(*devobj), GFP_KERNEL);
	if (!devobj) {
		GPS_ERR("-ENOMEM\n");
		err = -ENOMEM;
		return -1;
	}

	mt3326_gps_hw_init(hw);
	GPS_DBG("Registering chardev\n");
	ret = alloc_chrdev_region(&devobj->devno, 0, 1, GPS_DEVNAME);
	if (ret) {
		GPS_ERR("alloc_chrdev_region fail: %d\n", ret);
		goto error;
	} else {
		GPS_DBG("major: %d, minor: %d\n", MAJOR(devobj->devno), MINOR(devobj->devno));
	}
	cdev_init(&devobj->chdev, &mt3326_gps_fops);
	devobj->chdev.owner = THIS_MODULE;
	err = cdev_add(&devobj->chdev, devobj->devno, 1);
	if (err) {
		GPS_ERR("cdev_add fail: %d\n", err);
		goto error;
	}
	drvobj = kmalloc(sizeof(*drvobj), GFP_KERNEL);
	if (!drvobj) {
		err = -ENOMEM;
		goto error;
	}
	memset(drvobj, 0, sizeof(*drvobj));

	devobj->cls = class_create(THIS_MODULE, "gpsdrv");
	if (IS_ERR(devobj->cls)) {
		GPS_ERR("Unable to create class, err = %d\n", (int)PTR_ERR(devobj->cls));
		goto error;
	}
	devobj->dev = device_create(devobj->cls, NULL, devobj->devno, drvobj, "gps");
	drvobj->hw = hw;
	drvobj->pwrctl = 0;
	drvobj->suspend = 0;
	drvobj->state = GPS_STATE_UNSUPPORTED;
	drvobj->pwrsave = GPS_PWRSAVE_UNSUPPORTED;
	drvobj->rdelay = 50;
	drvobj->kobj = &devobj->dev->kobj;
	mutex_init(&drvobj->sem);

	err = mt3326_gps_create_attr(devobj->dev);
	if (err)
		goto error;

	/*initialize members */
	spin_lock_init(&gps_private.lock);
	init_waitqueue_head(&gps_private.read_wait);
	sema_init(&gps_private.sem, 1);

	gps_private.dat_len = 0;
	gps_private.dat_pos = 0;
	memset(gps_private.dat_buf, 0x00, sizeof(gps_private.dat_buf));

	/*set platform data:
	   a new device created for gps */
	platform_set_drvdata(dev, devobj);

	GPS_DBG("Done\n");
	return 0;

error:
	if (err == 0)
		cdev_del(&devobj->chdev);
	if (ret == 0)
		unregister_chrdev_region(devobj->devno, 1);
	kfree(devobj);
	kfree(drvobj);

	return -1;
}

/*****************************************************************************/
static int mt3326_gps_remove(struct platform_device *dev)
{
	int err;
	struct gps_dev_obj *devobj = (struct gps_dev_obj *)platform_get_drvdata(dev);
	struct gps_drv_obj *drvobj;

	if (!devobj) {
		GPS_ERR("null pointer: %p\n", devobj);
		return -1;
	}

	drvobj = (struct gps_drv_obj *)dev_get_drvdata(devobj->dev);
	if (!drvobj) {
		GPS_ERR("null pointer: %p\n", drvobj);
		return -1;
	}
	GPS_DBG("Unregistering chardev\n");

	cdev_del(&devobj->chdev);
	unregister_chrdev_region(devobj->devno, 1);

	mt3326_gps_hw_exit(devobj->hw);
	err = mt3326_gps_delete_attr(devobj->dev);
	if (err)
		GPS_ERR("delete attr fails: %d\n", err);
	device_destroy(devobj->cls, devobj->devno);
	class_destroy(devobj->cls);

	kfree(devobj);
	GPS_DBG("Done\n");
	return 0;
}

/*****************************************************************************/
static void mt3326_gps_shutdown(struct platform_device *dev)
{
	struct gps_dev_obj *devobj = (struct gps_dev_obj *)platform_get_drvdata(dev);

	GPS_DBG("Shutting down\n");
	mt3326_gps_hw_exit(devobj->hw);
}

/*****************************************************************************/
#ifdef CONFIG_PM
/*****************************************************************************/
static int mt3326_gps_suspend(struct platform_device *dev, pm_message_t state)
{
	int err = 0;
	struct gps_dev_obj *devobj = (struct gps_dev_obj *)platform_get_drvdata(dev);
	struct gps_drv_obj *drvobj;

	if (!devobj) {
		GPS_ERR("null pointer: %p\n", devobj);
		return -1;
	}

	drvobj = (struct gps_drv_obj *)dev_get_drvdata(devobj->dev);
	if (!drvobj) {
		GPS_ERR("null pointer: %p\n", drvobj);
		return -1;
	}

	if (state.event == PM_EVENT_SUSPEND)
		err = mt3326_gps_dev_suspend(drvobj);
	else
		GPS_DBG("dev = %p, event = %u,", dev, state.event);
	return err;
}

/*****************************************************************************/
static int mt3326_gps_resume(struct platform_device *dev)
{
	struct gps_dev_obj *devobj = (struct gps_dev_obj *)platform_get_drvdata(dev);
	struct gps_drv_obj *drvobj = (struct gps_drv_obj *)dev_get_drvdata(devobj->dev);

	return mt3326_gps_dev_resume(drvobj);
}

/*****************************************************************************/
#endif /* CONFIG_PM */
/*****************************************************************************/
#ifdef CONFIG_OF
static const struct of_device_id apgps_of_ids[] = {
	{.compatible = "mediatek,mt3326-gps",},
	{}
};
#endif
static struct platform_driver mt3326_gps_driver = {
	.probe = mt3326_gps_probe,
	.remove = mt3326_gps_remove,
	.shutdown = mt3326_gps_shutdown,
#if defined(CONFIG_PM)
	.suspend = mt3326_gps_suspend,
	.resume = mt3326_gps_resume,
#endif
	.driver = {
		   .name = GPS_DEVNAME,
		   .bus = &platform_bus_type,
#ifdef CONFIG_OF
		   .of_match_table = apgps_of_ids,
#endif
		   },
};

/*****************************************************************************/
static int __init mt3326_gps_mod_init(void)
{
	int ret = 0;

	GPS_TRC();

	/* ret = driver_register(&mt3326_gps_driver); */
	ret = platform_driver_register(&mt3326_gps_driver);

	return ret;
}

/*****************************************************************************/
static void __exit mt3326_gps_mod_exit(void)
{
	GPS_TRC();
	platform_driver_unregister(&mt3326_gps_driver);
}

/*****************************************************************************/
module_init(mt3326_gps_mod_init);
module_exit(mt3326_gps_mod_exit);
/*****************************************************************************/
MODULE_AUTHOR("MingHsien Hsieh <MingHsien.Hsieh@mediatek.com>");
MODULE_DESCRIPTION("MT3326 GPS Driver");
MODULE_LICENSE("GPL");
#endif