diff mbox

[v4] ARM: dts: exynos5422-odroidxu3: Hook up PWM and use it for LEDs

Message ID 84iobwuj23.wl-peter.chubb@nicta.com.au (mailing list archive)
State New, archived
Headers show

Commit Message

Peter Chubb May 13, 2015, 11:57 p.m. UTC
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.kozlowski@samsung.com>
Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>
---
 arch/arm/boot/dts/exynos5422-odroidxu3.dts | 50 +++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 14 deletions(-)

Comments

Anand Moon July 30, 2015, 8:09 p.m. UTC | #1
Hi Peter,

On 14/05/2015, Peter Chubb <peter.chubb@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.kozlowski@samsung.com>
> Signed-off-by: Peter Chubb <peter.chubb@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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Peter Chubb July 31, 2015, 11:23 p.m. UTC | #2
>>>>> "Anand" == Anand Moon <linux.amoon@gmail.com> writes:

Anand> Hi Peter,

Hi Anand,
   You have  LEDS-PWM built as a module --- try modprobe leds-pwm

I'm sorry, I can't try this right now -- we've just moved offices,
and the Odroid XU3 is still packed in the bottom of a box somewhere.


Peter C
diff mbox

Patch

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";
+};