工具与软件：
TPIC2810 是一款基于 I2C 的8位 LED 驱动器、可在下面列出的少数 AM62x EVM 上使用：
此常见问题解答将展示如何在 AM62x EVM 上启用和使用。
在 AM62x EVM 上、TPIC2810连接到 WKUP_I2C0总线。 请注意、TPIC2810的地址为0x60。
EVM 的产品页面上提供了指向原理图的链接。
在器件树中、需要设置引脚多路复用、将节点参考为 I2C、最后通过 LED-GPIO 更改默认状态。
diff --git a/arch/arm64/boot/dts/ti/k3-am625-sk.dts b/arch/arm64/boot/dts/ti/k3-am625-sk.dts
index b17379781..e6b18e208 100644
--- a/arch/arm64/boot/dts/ti/k3-am625-sk.dts
+++ b/arch/arm64/boot/dts/ti/k3-am625-sk.dts
@@ -120,6 +120,74 @@ wlan_en: regulator-7 {
pinctrl-names = "default";
pinctrl-0 = <&wlan_en_pins_default>;
};
+
+ led-controller {
+ compatible = "gpio-leds";
+
+ led-0 {
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <1>;
+ gpios = <&exp2 0 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-1 {
+ color = <LED_COLOR_ID_RED>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <2>;
+ gpios = <&exp2 1 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-2 {
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <3>;
+ gpios = <&exp2 2 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-3 {
+ color = <LED_COLOR_ID_AMBER>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <4>;
+ gpios = <&exp2 3 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-4 {
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <5>;
+ gpios = <&exp2 4 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-5 {
+ color = <LED_COLOR_ID_RED>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <6>;
+ gpios = <&exp2 5 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-6 {
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <7>;
+ gpios = <&exp2 6 GPIO_ACTIVE_HIGH>;
+ default-state = "off";
+ };
+
+ led-7 {
+ color = <LED_COLOR_ID_AMBER>;
+ function = LED_FUNCTION_HEARTBEAT;
+ function-enumerator = <8>;
+ linux,default-trigger = "heartbeat";
+ gpios = <&exp2 7 GPIO_ACTIVE_HIGH>;
+ };
+ };
};
&main_pmx0 {
@@ -193,6 +261,15 @@ AM62X_IOPAD(0x128, PIN_INPUT, 7) /* (B23) MMC2_SDWP.GPIO0_72 */
};
};
+&mcu_pmx0 {
+ tpic_pins_default: tpic-default-pins {
+ pinctrl-single,pins = <
+ AM62X_MCU_IOPAD(0x004c, PIN_INPUT, 0) /* (B9) WKUP_I2C0_SCL */
+ AM62X_MCU_IOPAD(0x0050, PIN_INPUT, 0) /* (A9) WKUP_I2C0_SDA */
+ >;
+ };
+};
+
&main_i2c1 {
exp1: gpio@22 {
compatible = "ti,tca6424";
@@ -285,6 +362,21 @@ mbox_m4_0: mbox-m4-0 {
};
};
+&wkup_i2c0 {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&tpic_pins_default>;
+ clock-frequency = <400000>;
+
+ exp2: gpio@60 {
+ compatible = "ti,tpic2810";
+ reg = <0x60>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ gpio-line-names = "LED0","LED1","LED2","LED3","LED4","LED5","LED6","LED7";
+ };
+};
+
&ospi0 {
status = "okay";
pinctrl-names = "default";
可以在器件树中更改 LED 的默认状态/触发器。
按照 SDK 文档中的说明构建设备树和内核模块： https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_00_07_04/exports/docs/linux/sdk.html Foundational_Components_Kernel_Users_Guide
编译.dtb 和映像并将其加载到 EVM 中。
root@am62xx-evm:~# cd /sys/class/leds/ root@am62xx-evm:/sys/class/leds# ls -lt total 0 lrwxrwxrwx 1 root root 0 Apr 28 17:42 amber:heartbeat-8 -> ../../devices/platform/led-controller/leds/amber:heartbeat-8 lrwxrwxrwx 1 root root 0 Apr 28 17:42 green:indicator-7 -> ../../devices/platform/led-controller/leds/green:indicator-7 lrwxrwxrwx 1 root root 0 Apr 28 17:42 mmc0:: -> ../../devices/platform/bus@f0000/fa10000.mmc/leds/mmc0:: lrwxrwxrwx 1 root root 0 Apr 28 17:42 mmc1:: -> ../../devices/platform/bus@f0000/fa00000.mmc/leds/mmc1:: lrwxrwxrwx 1 root root 0 Apr 28 17:42 am62-sk:green:heartbeat -> ../../devices/platform/leds/leds/am62-sk:green:heartbeat lrwxrwxrwx 1 root root 0 Apr 28 17:42 amber:indicator-4 -> ../../devices/platform/led-controller/leds/amber:indicator-4 lrwxrwxrwx 1 root root 0 Apr 28 17:42 green:indicator-1 -> ../../devices/platform/led-controller/leds/green:indicator-1 lrwxrwxrwx 1 root root 0 Apr 28 17:42 green:indicator-3 -> ../../devices/platform/led-controller/leds/green:indicator-3 lrwxrwxrwx 1 root root 0 Apr 28 17:42 green:indicator-5 -> ../../devices/platform/led-controller/leds/green:indicator-5 lrwxrwxrwx 1 root root 0 Apr 28 17:42 mmc2:: -> ../../devices/platform/bus@f0000/fa20000.mmc/leds/mmc2:: lrwxrwxrwx 1 root root 0 Apr 28 17:42 red:indicator-2 -> ../../devices/platform/led-controller/leds/red:indicator-2 lrwxrwxrwx 1 root root 0 Apr 28 17:42 red:indicator-6 -> ../../devices/platform/led-controller/leds/red:indicator-6 root@am62xx-evm:/sys/class/leds# echo 1 > amber\:indicator-4/brightness
所有 LED 均已填充在/sys/class/leds 中。 对于简单的切换、将1/0回显到亮度目录。
有关使用 SYSFS 连接 LED 的更多信息、请参见此处获取 SYSFS 类 LED 文档： git.ti.com/.../sysfs-class-led