MTK驱动（84）---GPS 配置

1. 查看原理图：
GPS xLNA
--GPIO_GPS_LNA_EN // 据此查到对应GPIO79(AL27)

2. 修改dws：

3. 修改dts：
/* CONSYS GPIO standardization */
&pio {
consys_pins_default: default {

};

gpslna_pins_init: gpslna@0 {

pins_cmd_dat {
pins = <PINMUX_GPIO79__FUNC_GPIO79>;
slew-rate = <0>;
bias-disable;
output-low;
};
};

gpslna_pins_oh: gpslna@1 {

pins_cmd_dat {
pins = <PINMUX_GPIO79__FUNC_GPIO79>;
slew-rate = <1>;
output-high;
};
};

gpslna_pins_ol: gpslna@2 {

pins_cmd_dat {
pins = <PINMUX_GPIO79__FUNC_GPIO79>;
slew-rate = <1>;
output-low;
};
};

};

&consys {
pinctrl-names = "default", "gps_lna_state_init", "gps_lna_state_oh", "gps_lna_state_ol";
pinctrl-0 = <&consys_pins_default>;
pinctrl-1 = <&gpslna_pins_init>;
pinctrl-2 = <&gpslna_pins_oh>;
pinctrl-3 = <&gpslna_pins_ol>;
status = "okay";

};


二、由省gps晶体，改为不省gps晶体
1. 修改alps\device\mediatek\mt6580\WMT_SOC.cfg
- co_clock_flag=1 // 默认为省晶体
+ co_clock_flag=0

2. 修改alps\vendor\mediatek\proprietary\custom\k80hd_bsp_fwv_512m\cgen\cfgdefault\CFG_GPS_Default.h
ap_nvram_gps_config_struct stGPSConfigDefault =
{
/* if chip detector say it's not 3332 use /dev/stpgps,else use /ttyMT1 */
{'/','d','e','v','/','s','t','p','g','p','s',0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0},
/* 0:s/w, 1:none, 2:h/w */
1,

/* 26MHz */
26000000,
/* default is 0ppm, by chip definetion. 6620 is 500, else 2000 */
0,
/* 0:16.368MHz TCXO */
- 0xFE, // 默认为0xFF，省晶体要配为0xFE
+ 0xFF, // 默认为0xFF，不省晶体要配为0xFF

3. 更改modem配置-重新配modem