有时需要查看GPIO 被哪个模块占用，需要打印LOG分析
打开debug 开关：
文件：alps/kernel-4.9/driver/pinctrl/mediatek/pinctrl-mtk-common.h
#define GPIO_DEBUG
在文件：alps/kernel-4.9/driver/pinctrl/mediatek/pinctrl-mtk-common.c
static int mtk_pinctrl_set_gpio_mode(struct mtk_pinctrl *pctl,
int pin, unsigned long mode)
{
#ifndef GPIO_DEBUG
return mtk_pinctrl_update_gpio_value(pctl, pin, mode,
pctl->devdata->n_pin_mode, pctl->devdata->pin_mode_grps);
#else
pr_info("config pin = %d, mode = %d\n", pin, (int)mode);
if(pin == 105) //可以添加需要配置的gpio进行dump抓取
dump_stack();
mtk_pinctrl_update_gpio_value(pctl, pin, mode,
pctl->devdata->n_pin_mode, pctl->devdata->pin_mode_grps);
pr_info("set pin = %d, mode = %d\n", pin,
mtk_pinctrl_get_gpio_mode(pctl, pin));
return 0;
#endif
}
分析log,
cat /poc/kmsg
．．．．．．
[ 1.461597] <0>.(1)[1:swapper/0]m300_probe: ~~~~~Enter!!
[ 1.461612] <0>.(1)[1:swapper/0]m300_parse_dt: restGPIO: 383
[ 1.461616] <0>.(1)[1:swapper/0]m300_parse_dt: power GPIO: 444
[ 1.461630] <0>.(1)[1:swapper/0]config pin = 112, mode = 0
[ 1.461637] <0>.(1)[1:swapper/0]set pin = 112, mode = 0
[ 1.461648] <0>.(1)[1:swapper/0]config pin = 102, mode = 0
[ 1.461653] <0>.(1)[1:swapper/0]set pin = 102, mode = 0
．．．．．．
可见m300模块占用了gpio112,gpio102