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--- products:sbc:common:applications:gpio:pwm [2023/12/25 22:01]
jacobe [Control PWM]
+++ products:sbc:common:applications:gpio:pwm [2024/08/22 02:40] (current)
nick
@@ Line 17: / Line 17: @@
 ===== Enable PWM =====
+==== Linux ====
 In order to use the PWM, you need to enable the PWM function via [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].
@@ Line 122: / Line 125: @@
 </tabbox>
+==== Android ====
+<tabbox VIM4>
+The ''PWM'' function is disabled by default, you need to modify the dts to enable it.
+```diff
+diff --git a/arch/arm64/boot/dts/amlogic/kvim4.dts b/arch/arm64/boot/dts/amlogic/kvim4.dts
+--- a/arch/arm64/boot/dts/amlogic/kvim4.dts
++++ b/arch/arm64/boot/dts/amlogic/kvim4.dts
+ &pwm_ef {
++    pinctrl-names = "default";
++    pinctrl-0 = <&pwm_f_pins>;
+        status = "okay";
+ };
+diff --git a/arch/arm64/boot/dts/amlogic/kvim4n.dts b/arch/arm64/boot/dts/amlogic/kvim4n.dts
+--- a/arch/arm64/boot/dts/amlogic/kvim4n.dts
++++ b/arch/arm64/boot/dts/amlogic/kvim4n.dts
+ &pwm_ef {
++    pinctrl-names = "default";
++    pinctrl-0 = <&pwm_f_pins>;
+        status = "okay";
+ };
+diff --git a/arch/arm64/boot/dts/amlogic/mesont7_an400-panel.dtsi b/arch/arm64/boot/dts/amlogic/mesont7_an400-panel.dtsi
+--- a/arch/arm64/boot/dts/amlogic/mesont7_an400-panel.dtsi
++++ b/arch/arm64/boot/dts/amlogic/mesont7_an400-panel.dtsi
+@@ -1442,13 +1442,13 @@
+        backlight1{
+                compatible = "amlogic, backlight-t7";
+-               status = "okay";
++               status = "disabled";
+                index = <1>;
+                key_valid = <0>;
+                pinctrl-names = "pwm_on",
+                                "pwm_off";
+-               pinctrl-0 = <&pwm_f_pins>;
+-               pinctrl-1 = <&bl1_pwm_off_pins>;
+                pinctrl_version = <2>; /* for uboot */
+                interrupts = <0 197 1
+```
+<tabbox VIM1S>
+The ''PWM'' function is disabled by default, you need to modify the dts to enable it.
+```diff
+--- a/arch/arm64/boot/dts/amlogic/kvim1s.dts
++++ b/arch/arm64/boot/dts/amlogic/kvim1s.dts
+@@ -1411,8 +1411,8 @@
+ };
+ &pwm_ef {
+-       /*pinctrl-0 = <&pwm_f_pins2>;*/
+-       /*pinctrl-names = "default";*/
++       pinctrl-0 = <&pwm_f_pins2>;
++       pinctrl-names = "default";
+        status = "okay";
+ };
+```
+</tabbox>
 ===== Control PWM =====
@@ Line 152: / Line 221: @@
 echo 500000 | sudo tee /sys/class/pwm/pwmchip0/pwm1/duty_cycle
 echo 1 | sudo tee /sys/class/pwm/pwmchip0/pwm1/enable
-```
-<tabbox VIM4/4N with 5.15 kernel>
-```shell
-echo 1 | sudo tee /sys/class/pwm/pwmchip12/export
-echo 1000000 | sudo tee /sys/class/pwm/pwmchip12/pwm1/period
-echo 500000 | sudo tee /sys/class/pwm/pwmchip12/pwm1/duty_cycle
-echo 1 | sudo tee /sys/class/pwm/pwmchip0/pwm12/enable
 ```
@@ Line 186: / Line 246: @@
 ```shell
 echo 0 | sudo tee /sys/class/pwm/pwmchip0/pwm1/enable
-```
-<tabbox VIM4/4N with 5.15 kernel>
-```shell
-echo 0 | sudo tee /sys/class/pwm/pwmchip12/pwm1/enable
 ```

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