Krum

Hello, Setup Yocto branch: Kirkstone (honister back-ports disabled) Layers / commits meta-odroid 06f8d2c (last week’s master) poky kirkstone (bitbake 2.2.0) Kernel: linux = v5.15 What I changed so far Enabled the driver Added a linux-hardkernel_%.bbappend with: CONFIG_PWM=y CONFIG_PWM_MESON=y Patched the Device Tree (added a new layer to patch in yocto using devtool): From 9f296f4b8f636b12ef8c0a4720cf0d25d9eeb810 Mon Sep 17 00:00:00 2001 From: OpenEmbedded <oe.patch@oe> Date: Thu, 17 Jul 2025 15:50:18 -0400 Subject: [PATCH] some changes to source for pwm --- arch/arm64/boot/dts/amlogic/meson-gx.dtsi | 2 +- .../arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi index 32cc9fab4490..f7abfd4746d2 100644 --- a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi @@ -330,7 +330,7 @@ pwm_ab: pwm@8550 { compatible = "amlogic,meson-gx-pwm", "amlogic,meson-gxbb-pwm"; reg = <0x0 0x08550 0x0 0x10>; #pwm-cells = <3>; - status = "disabled"; + status = "okay"; }; pwm_cd: pwm@8650 { diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts index 201596247fd9..0f5e52e7096c 100644 --- a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts @@ -416,3 +416,17 @@ &usb0 { &usb1 { status = "okay"; }; + +&pwm_ab { + status = "okay"; + pinctrl-names = "default"; + pinctrl-0 = <&pwm_a_x_pins>; +}; + +&pinctrl { + pwm_a_x_pins: pwm_a_x { + groups = "pwm_a_x"; + functions = "pwm_a_x"; + bias-pull-disable; + }; +}; Symptoms modprobe pwm-meson dosen't loads, nothing in dmesg. But the file are here : root@odroid-c2:~# dmesg | grep pwm root@odroid-c2:~# ls /sys/class/pwm* pwmchip0 root@odroid-c2:~# ls /sys/class/pwm/pwmchip0/ device export npwm power subsystem uevent unexport root@odroid-c2:~# modprobe pwm-meson root@odroid-c2:~# dmesg | grep pwm root@odroid-c2:~# ls /sys/class/pwm/pwmchip0/ device export npwm power subsystem uevent unexport root@odroid-c2:~# echo 0 > /sys/class/pwm/pwmchip0/export root@odroid-c2:~# ls /sys/class/pwm/pwmchip0/pwm0/ capture duty_cycle enable period polarity power uevent /sys entries: /sys/class/pwm/pwmchip0/ ├── export ├── npwm ├── device ├── power ├── subsystem ├── uevent ├── unexport └── pwm0/ ├── freq0 ├── duty0 └── enable0 I run (root): root@odroid-c2:~# echo 20000000 > /sys/class/pwm/pwmchip0/pwm0/period root@odroid-c2:~# echo 1500000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle root@odroid-c2:~# echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable but nothing happen. Questions Has anyone successfully driven hardware PWM on the C2 with current meta-odroid + Kirkstone? Any known quirks with the pinctrl or the pwm-meson driver on kernels ≥ 5.15? Sample DTS snippet or working .bbappend would be greatly appreciated! Thanks in advance. Krum