LED

Introduction

EC-R3588SPCThere is a three color LED light and two monochrome lights
on the development board, as shown in the following table：


LEDs can be controlled by using the LED device subsystem or by
directly operating GPIO.

Controlling LEDs by device

Linux has its own LED subsystem for LED devices. In EC-R3588SPC, LEDs
are configured as LED class devices.You can control them via
"/sys/class/leds/".

Tricolor led：

Blue:  Turn on after the system powers on.

Red:   defined by user.

Green: defined by user.

Monochrome led：

Ext Yellow : Relay work in indicator(Silk screen：L2)

Ext Green : defined by user.  (Silk screen：L1)

You can change the behavior of each LED by using the echo command to
write command to its brightness property:

Tricolor led：

   echo 1 > sys/class/leds/\:power/brightness //Blue led on
   echo 0 > sys/class/leds/\:power/brightness //Blue led off

   echo 1 > sys/class/leds/\:user/brightness //Red led on
   echo 0 > sys/class/leds/\:user/brightness //Red led off

   echo 1 > sys/class/leds/\:user1/brightness //Green led on
   echo 0 > sys/class/leds/\:user1/brightness //Green led off

L1 Monochrome led：

   echo 1 > /sys/class/leds/ext_led1/brightness //Ext Yellow led on
   echo 0 > /sys/class/leds/ext_led1/brightness //Ext Yellow led off

L2 Monochrome led：

   echo 1 > /sys/class/leds/ext_led2/brightness //Ext Green led on
   echo 0 > /sys/class/leds/ext_led2/brightness //Ext Green led off

Using trigger control LED

Trigger contains a variety of ways to control the LED, here with two
examples to illustrate.

Simple trigger LED

Complex trigger LED

For more information, please read the document "leds-class.txt".

First of all, we need to know how many LED definition, while the
corresponding property of the LED is.

Define Tricolor led node in file "kernel/arch/arm64/boot/dts/rockchip
/roc-rk3588s-pc.dtsi"：

   firefly_leds: leds {
       compatible = "gpio-leds";
       power_led: power {
           label = ":power"; //blue led
           linux,default-trigger = "ir-power-click";
           default-state = "on";
           gpios = <&gpio1 RK_PD5 GPIO_ACTIVE_HIGH>;
           pinctrl-names = "default";
           pinctrl-0 = <&led_power>;
       };

       user_led: user {
           label = ":user"; //red led
           linux,default-trigger = "ir-user-click";
           default-state = "off";
           gpios = <&gpio3 RK_PB2 GPIO_ACTIVE_HIGH>;
           pinctrl-names = "default";
           pinctrl-0 = <&led_user>;
       };

       user1_led: user1 {
           label = ":user1"; //green led
           default-state = "off";
           gpios = <&gpio3 RK_PC0 GPIO_ACTIVE_HIGH>;
           pinctrl-names = "default";
           pinctrl-0 = <&led_user1>;
       };
   };

Define Monochrome led node in file
"kernel/arch/arm64/boot/dts/rockchip/roc-rk3588s-pc-ext.dtsi" ：

   &firefly_leds {
                  ext_yellow_led: ext_led1 {
                          gpios = <&gpio3 RK_PB7 GPIO_ACTIVE_HIGH>;//yellow led
                          pinctrl-names = "default";
                          pinctrl-0 = <&led_user2>;
                  };

                  ext_green_led: ext_led2 {
                          gpios = <&gpio3 RK_PC1 GPIO_ACTIVE_HIGH>;//green led
                          pinctrl-names = "default";
                          pinctrl-0 = <&led_user3>;
                  };
   };

Note: The value of "compatible" must match the one in "drivers/leds
/leds-gpio.c".

Simple trigger LED

It is a simple trigger mode to control LEDs, as follows on the default
open yellow LED. And EC-R3588SPC's yellow LED will be turned on after
boot.

(1) Defined LED trigger In the "kernel/drivers/leds/trigger/led-
firefly-demo.c" add the following:

   DEFINE_LED_TRIGGER(ledtrig_default_control);

(2) Register the trigger.

   led_trigger_register_simple("ir-user-click", &ledtrig_default_control);

(3) Control the LED.

   led_trigger_event(ledtrig_default_control, LED_FULL);     #yellow led on

（4）Enable LED demo.

led-firefly-demo is disabled in default,if you need to open the demo
drive can use the following patch:

   --- a/kernel/arch/arm64/boot/dts/rockchip/rk3588-firefly-demo.dtsi
   +++ b/kernel/arch/arm64/boot/dts/rockchip/rk3588-firefly-demo.dtsi
   @@ -52,7 +52,7 @@
               led_demo: led_demo {
   -                status = "disabled";
   +                status = "okay";
                    compatible = "firefly,rk3588-led";
                    };

Complex trigger LED

The following is the trigger mode control LED complex example, "timer
trigger" is to let the LED to achieve constant light off effect.

We need to configure the timer trigger on the kernel.

In the "kernel-5.10" path using "make menuconfig", in accordance with
the following method to chose "timer trigger" driver.

   Device Drivers
   --->LED Support
      --->LED Trigger support
         --->LED Timer Trigger

Save the configuration and compile the kernel, the "kernel.img" burn
EC-R3588SPC board. We can use the serial input command, you can see
the blue light non-stop interval flashing.

   echo "timer" > /sys/class/leds/:user/trigger

The user can also use the "cat" command to get the available values
for the trigger:

   # cat /sys/class/leds/:user/trigger
   none ir-power-click rfkill-any rfkill-none test_ac-online test_battery-charging-or-full 
   test_battery-charging test_battery-full test_battery-charging-blink-full-solid 
   test_usb-online mmc0 [timer] heartbeat backlight default-on ir-user-click mmc1 
   rfkill0 tcpm-source-psy-6-0022-online rfkill1 rfkill2