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linux核心gpio裝置樹,linux-kernel - 如何将樹莓派上的gpio引腳與裝置驅動程式中的裝置樹一起使用? - SO中文參考 - www.soinside.com...

[我嘗試開發一個驅動程式,以通過樹莓派上的gpio引腳控制自定義硬體。

我希望将新的gpio_desc與裝置樹結合使用。但是我無法使它正常工作。

如果我嘗試通過red = gpio_to_desc( 17 );一切正常,但

green = gpiod_get(dev, "carr", GPIOD_OUT_LOW);

似乎跳過了裝置樹。

在dmesg中:[ 4326.023976] carrera_driver carrera.0: GPIO lookup for consumer carr

[ 4326.023986] carrera_driver carrera.0: using lookup tables for GPIO lookup

[ 4326.023999] carrera_driver carrera.0: No GPIO consumer carr found

[ 4326.024010] carrera_driver carrera.0: Failed to get carr GPIO: -2

[ 4326.024034] carrera_driver: probe of carrera.0 failed with error -2

裝置樹:/dts-v1/;

/plugin/;

/{

compatible = "brcm,bcm2835";

[email protected] {

target = ;

__overlay__ {

carrera_pins: carrera_pins {

compatible = "kru,carrera";

brcm,pins = <18>;

brcm,function = <1>; // out

brcm,pull = <0>;

};

};

};

[email protected] {

target = ;

__overlay__ {

carrera: carrera {

compatible = "kru,carrera";

#gpio-cells = <2>;

pinctrl-names = "default";

pinctrl-0 = ;

carr-gpios = ;

};

};

};

};

我認為這是發生與驅動程式進行裝置樹映射的部分struct platform_device linuxmag = {

.name = "carrera",

.id = 0,

.dev = {

.release = linuxmag_release,

}

};

static struct of_device_id linmag_match[] = {

{.compatible = "kru,carrera"},

{}

};

static struct platform_driver mydriver = {

.probe = linuxmag_probe_device,

.remove = linuxmag_remove_device,

.driver = {

.name = "carrera_driver",

.of_match_table = linmag_match,

}

};

我認為我缺少非常重要的東西。

有人舉了一個例子,說明如何至少在帶裝置樹的gpiod子子產品上使用led?我在Internet上找到的所有内容都有不完整的裝置樹或沒有代碼。