Hi Peter,

On 14/05/2015, Peter Chubb <peter.ch...@nicta.com.au> wrote:
>
> PWM output wasn't working because it wasn't hooked up to its pincontrol.
> This patch:
>    - hooks up PWM to its pincontrol, and documents what
>      the outputs are on the XU3
>    - switches the LEDs that are on PWM outputs to use PWM
>      rather than GPIO.
>
> The main effect is that the brightness of the LEDs can be controlled, and
> user-mode fan control is enabled via /sys/class/pwm
>
> Acked-by: Krzysztof Kozlowski <k.kozlow...@samsung.com>
> Signed-off-by: Peter Chubb <peter.ch...@nicta.com.au>
> ---
>  arch/arm/boot/dts/exynos5422-odroidxu3.dts | 50
> +++++++++++++++++++++---------
>  1 file changed, 36 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3.dts
> b/arch/arm/boot/dts/exynos5422-odroidxu3.dts
> index f0ce60b..0c62156 100644
> --- a/arch/arm/boot/dts/exynos5422-odroidxu3.dts
> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3.dts
> @@ -287,25 +287,35 @@
>               status = "okay";
>       };
>
> -     leds {
> -             compatible = "gpio-leds";
> -             heartbeat {
> -                     label = "blue:heartbeart";
> -                     gpios = <&gpb2 2 0>;
> -                     default-state = "off";
> -                     linux,default-trigger = "heartbeat";
> +     pwmleds {
> +             compatible = "pwm-leds";
> +
> +             greenled {
> +                     label = "green:mmc0";
> +                     pwms = <&pwm 1 2000000 0>;
> +                     pwm-names = "pwm1";
> +                     /*
> +                      * Green LED is much brighter than the others
> +                      * so limit its max brightness
> +                      */
> +                     max_brightness = <127>;
> +                     linux,default-trigger = "mmc0";
>               };
>
> -             eMMC {
> -                     label = "green:eMMC";
> -                     gpios = <&gpb2 1 0>;
> -                     default-state = "off";
> -                     linux,default-trigger = "mmc0";
> +             blueled {
> +                     label = "blue:heartbeat";
> +                     pwms = <&pwm 2 2000000 0>;
> +                     pwm-names = "pwm2";
> +                     max_brightness = <255>;
> +                     linux,default-trigger = "heartbeat";
>               };
> +     };
>
> -             microSD {
> +     gpioleds {
> +             compatible = "gpio-leds";
> +             redled {
>                       label = "red:microSD";
> -                     gpios = <&gpx2 3 0>;
> +                     gpios = <&gpx2 3 GPIO_ACTIVE_HIGH>;
>                       default-state = "off";
>                       linux,default-trigger = "mmc1";
>               };
> @@ -415,3 +425,15 @@
>               shunt-resistor = <10000>;
>       };
>  };
> +
> +&pwm {
> +     /*
> +      * PWM 0 -- fan
> +      * PWM 1 -- Green LED
> +      * PWM 2 -- Blue LED
> +      * PWM 3 -- on MIPI connector for backlight
> +      */
> +     pinctrl-0 = <&pwm0_out &pwm1_out &pwm2_out &pwm3_out>;
> +     pinctrl-names = "default";
> +     status = "okay";
> +};
> --
> 2.1.4
>
> --
> Dr Peter Chubb                                        peter.chubb AT 
> nicta.com.au
> http://www.ssrg.nicta.com.au          Software Systems Research Group/NICTA

I wonder how PWM can be enabled on the odroidxu3 board.

I could not find the node getting populated in the /sys/class/leds/

root@odroidxu3:l# la -la   /sys/class/leds/
total 0
drwxr-xr-x  2 root root 0 Jul 31 04:56 .
drwxr-xr-x 47 root root 0 Jul 31 04:56 ..
lrwxrwxrwx  1 root root 0 Jul 31 04:56 red:microSD ->
../../devices/platform/gpioleds/leds/red:microSD

Well I have enable. following  config options in .config.

CONFIG_LEDS_CLASS=y
CONFIG_LEDS_GPIO=y
CONFIG_LEDS_PWM=m
CONFIG_LEDS_SYSCON=y
# CONFIG_LEDS_PM8941_WLED is not set
CONFIG_LEDS_TRIGGERS=y
CONFIG_LEDS_TRIGGER_TIMER=y
CONFIG_LEDS_TRIGGER_ONESHOT=y
CONFIG_LEDS_TRIGGER_HEARTBEAT=y
CONFIG_LEDS_TRIGGER_BACKLIGHT=y
# CONFIG_LEDS_TRIGGER_CPU is not set
CONFIG_LEDS_TRIGGER_GPIO=y
CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
CONFIG_LEDS_TRIGGER_TRANSIENT=y
# CONFIG_LEDS_TRIGGER_CAMERA is not set

Please let me know if I am missing some thing.

-Anand Moon
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