该驱动比较简单，gps模组是基于uart的自力模块，rk3188经由过程gpio控制gps(打开与封闭)，然后将gps uart的NMEA data接收，并传递给上层（gpstest.apk）。
1. gps 模组gpio的┞菲握： gps vcc_en,gps_reset pin的定义：
     platform_device :
#if defined(CONFIG_RK29_GPS)
#include "../../../drivers/misc/gps/rk29_gps.h"

#define RK29_GPS_POWER_PIN RK30_PIN1_PB5
#define RK29_GPS_RESET_PIN RK30_PIN0_PD5

int rk29_gps_power_up(void)
{
int ret;
printk("%s \n", __FUNCTION__);

ret = gpio_request(RK29_GPS_POWER_PIN, NULL);
if (ret != 0) {
gpio_free(RK29_GPS_POWER_PIN);
printk("gps power error\n");
return -EIO;
}
//gpio_pull_updown(RK29_GPS_POWER_PIN, PullEnable);
gpio_direction_output(RK29_GPS_POWER_PIN, GPIO_HIGH);

return 0;
}

int rk29_gps_power_down(void)
{
printk("%s \n", __FUNCTION__);

//gpio_request(RK29_GPS_POWER_PIN, NULL);
gpio_direction_output(RK29_GPS_POWER_PIN, GPIO_LOW);

return 0;
}

int rk29_gps_reset_set(int level)
{
gpio_request(RK29_GPS_RESET_PIN, NULL);
if (level)
gpio_direction_output(RK29_GPS_RESET_PIN, GPIO_HIGH);
else
gpio_direction_output(RK29_GPS_RESET_PIN, GPIO_LOW);

return 0;
}

struct rk29_gps_data rk29_gps_info = {
.power_up = rk29_gps_power_up,
.power_down = rk29_gps_power_down,
.reset = rk29_gps_reset_set,
.uart_id = 3,
};

struct platform_device rk29_device_gps = {
.name = "gps",//.name = "rk29_gps",
.id = -1,
.dev = {
.platform_data = http://www.sjsjw.com/100/000185MYM009209/&rk29_gps_info,
}
};
#endif

在体系中添加该device
static struct platform_device *devices[] __initdata = http://www.sjsjw.com/100/000185MYM009209/{
.....
//add liuxd 20141231
#if defined(CONFIG_RK29_GPS) 
&rk29_device_gps,
#endif
.......
};

/kernel/driver/misc/gps/下面添加gps driver:
注册成功后/dev/gps结点会生成，下文的gps.default.so可以经由过程/dev/gps打开与封闭gps。
2.rk3188 uart3的打开。
   2.1打开gps uart3的config
   2.2包管 uart3所复竽暌姑的gpio 在软件里被初始化为uart func pin.
   2.3 chmod 777 /dev/ttyS3
如不雅此时成功，就可以用串口助手攫取到gps 的nmea 数据了。


3.在gps在hal层添加gps.default.so
struct hw_module_t HAL_MODULE_INFO_SYM = {
    .tag = HARDWARE_MODULE_TAG,
    .version_major = 1,
    .version_minor = 0,
    .id = GPS_HARDWARE_MODULE_ID,
    .name = "QUECTEL GPS Module",
    .author = "Joe.Wang",
    .methods = &gps_module_methods,
};

4.app下安装gpstest.apk
5.收星测试。