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librem5-devkit: Let LED use PWM

PATCH Applied Guido Günther 3 participants 7 messages Oct 9, 2022 – Oct 29, 2022

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Device tree bindings Arm i.MX and Layerscape LED
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Guido Günther

author
#0 lore raw

cover librem5-devkit: Let LED use PWM

So far it used plain GPIO but we can use PWM for brightness control. While at that use function and color (it's a single color LED) and enable the pattern led trigger to make it more useful.

Guido Günther (3):
arm64: defconfig: Enable pattern LED trigger
arm64: dts: librem5-devkit: Make LED use PWM
arm64: dts: librem5-devkit: Use function and color rather than label

 .../dts/freescale/imx8mq-librem5-devkit.dts   | 22 ++++++++++++-------
 arch/arm64/configs/defconfig                  |  1 +
 2 files changed, 15 insertions(+), 8 deletions(-)
Signature · 1 line
2.35.1
author
#1 lore raw

PATCH 1/3 arm64: defconfig: Enable pattern LED trigger

This allows devices to easily use LED patterns from userspace.

Signed-off-by Guido Günther <[email protected]>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)
arch/arm64/configs/defconfig +1 -0
index 5b167649097e..68642b8aac3f 100644
@@ -956,6 +956,7 @@ CONFIG_LEDS_TRIGGER_HEARTBEAT=y
 CONFIG_LEDS_TRIGGER_CPU=y
 CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
 CONFIG_LEDS_TRIGGER_PANIC=y
+CONFIG_LEDS_TRIGGER_PATTERN=m
 CONFIG_EDAC=y
 CONFIG_EDAC_GHES=y
 CONFIG_EDAC_LAYERSCAPE=m
Signature · 1 line
2.35.1
#2 lore raw

Re: [PATCH v1 1/3] arm64: defconfig: Enable pattern LED trigger

Quoted 1 line · Guido Günther

This allows devices to easily use LED patterns from userspace.

Devices could use LED patterns even before. You need to explain why this should go to our defconfig which is used mostly by us, kernel developers. Not by end-users.

Quoted 3 lines
Signed-off-by Guido Günther <[email protected]>

---

Best regards,
Krzysztof

author
#3 lore raw

PATCH 2/3 arm64: dts: librem5-devkit: Make LED use PWM

In reply to Guido Günther

We can use PWM instead of just GPIO allowing us to control brightness.

Signed-off-by Guido Günther <[email protected]>
---
 .../dts/freescale/imx8mq-librem5-devkit.dts    | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)
arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts +11 -7
index 6445c6b90b5b..7e4b6d65fd89 100644
@@ -61,14 +61,12 @@ button-3 {
 	};
 
 	leds {
-		compatible = "gpio-leds";
-		pinctrl-names = "default";
-		pinctrl-0 = <&pinctrl_gpio_leds>;
+		compatible = "pwm-leds";
 
 		led1 {
 			label = "LED 1";
-			gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
-			default-state = "off";
+			max-brightness = <248>;
+			pwms = <&pwm2 0 50000 0>;
 		};
 	};
 

@@ -615,9 +613,9 @@ MX8MQ_IOMUXC_GPIO1_IO05_GPIO1_IO5	0x19  /* TOUCH RST */
 		>;
 	};
 
-	pinctrl_gpio_leds: gpioledgrp {
+	pinctrl_pwm_led: pwmledgrp {
 		fsl,pins = <
-			MX8MQ_IOMUXC_GPIO1_IO13_GPIO1_IO13	0x16
+			MX8MQ_IOMUXC_GPIO1_IO13_PWM2_OUT	0x16
 		>;
 	};
 

@@ -920,6 +918,12 @@ &pwm1 {
 	status = "okay";
 };
 
+&pwm2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pwm_led>;
+	status = "okay";
+};
+
 &snvs_pwrkey {
 	status = "okay";
 };
Signature · 1 line
2.35.1
Applied
#4 lore raw

Re: [PATCH v1 2/3] arm64: dts: librem5-devkit: Make LED use PWM

Quoted 3 lines · Guido Günther

We can use PWM instead of just GPIO allowing us to control brightness.

Signed-off-by Guido Günther <[email protected]>

Applied, thanks!

author
#5 lore raw

PATCH 3/3 arm64: dts: librem5-devkit: Use function and color rather than label

In reply to Guido Günther

Use predefined colors and function rather than making up a random label.

Signed-off-by Guido Günther <[email protected]>
---
 arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts +3 -1
index 7e4b6d65fd89..4c8904fba1c1 100644
@@ -7,6 +7,7 @@
 
 #include "dt-bindings/input/input.h"
 #include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/leds/common.h>
 #include "dt-bindings/pwm/pwm.h"
 #include "dt-bindings/usb/pd.h"
 #include "imx8mq.dtsi"

@@ -64,7 +65,8 @@ leds {
 		compatible = "pwm-leds";
 
 		led1 {
-			label = "LED 1";
+			function = LED_FUNCTION_STATUS;
+			color = <LED_COLOR_ID_RED>;
 			max-brightness = <248>;
 			pwms = <&pwm2 0 50000 0>;
 		};
Signature · 1 line
2.35.1
Applied
#6 lore raw

Re: [PATCH v1 3/3] arm64: dts: librem5-devkit: Use function and color rather than label

Quoted 3 lines · Guido Günther

Use predefined colors and function rather than making up a random label.

Signed-off-by Guido Günther <[email protected]>

Applied, thanks!