ARM: dts: sunxi: q8 A13 tablet backlight support

Hi Maxime,

This series seems to have fallen through the cracks, hence this resend.

Regards,

Hans

The sun5i die has a PWM controller that is compatible to the one on the A20. Add a device node for it.

---
 arch/arm/boot/dts/sun5i.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

index 78b993a..5e036a4 100644
@@ -543,6 +543,14 @@
 			reg = <0x01c20c90 0x10>;
 		};
 
+		pwm: pwm at 01c20e00 {
+			compatible = "allwinner,sun7i-a20-pwm";
+			reg = <0x01c20e00 0xc>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		lradc: lradc at 01c22800 {
 			compatible = "allwinner,sun4i-a10-lradc-keys";
 			reg = <0x01c22800 0x100>;

2.5.0

Add a pinmux setting for the first pwm channel. This is often used for backlight dimming on tablets.

---
 arch/arm/boot/dts/sun5i.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

index 5e036a4..f0714d3 100644
@@ -529,6 +529,13 @@
 				allwinner,drive = <SUN4I_PINCTRL_30_MA>;
 				allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
 			};
+
+			pwm0_pins: pwm0 {
+				allwinner,pins = "PB2";
+				allwinner,function = "pwm";
+				allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+			};
 		};
 
 		timer at 01c20c00 {

2.5.0

From: Chen-Yu Tsai <[email protected]>

Q8 format tablets use channel 0 of the PWM controller for backlight dimming.

---
Changes in v2:
-Enable the pwm controller in sunxi-q8-common.dtsi rather then in
sun8i-q8-common.dtsi

---
 arch/arm/boot/dts/sunxi-q8-common.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

index 17b26ff..b824146 100644
@@ -75,3 +75,9 @@
 		voltage = <400000>;
 	};
 };
+
+&pwm {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pwm0_pins>;
+	status = "okay";
+};

2.5.0

All A13 based q8 formfactor tablets use the same backlight setup, add a backlight devicetree node for controlling the backlight on these devices.

---
Changes in v2:
-Drop the comment about DCDC1SW, the axp209 used on A13 boards does not
have a DCDC1SW

---
 arch/arm/boot/dts/sun5i-q8-common.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

index 0641d68..a78e189 100644
@@ -41,11 +41,21 @@
  */
 #include "sunxi-q8-common.dtsi"
 
+#include <dt-bindings/pwm/pwm.h>
+
 / {
 	aliases {
 		serial0 = &uart1;
 	};
 
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>;
+		brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>;
+		default-brightness-level = <8>;
+		/* TODO: backlight uses axp gpio1 as enable pin */
+	};
+
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};

2.5.0

Hi,

No, it didn't fall through the cracks, I asked a question on the first patch and never got a reply.

The way we handled *all* the controllers so far is that the compatible was representing what the controllers what features the controller was exposing. This is the case for the clocks or pinctrl for example.

We should be consistent with that (beside the fact that using a compatible from a later SoC is wrong).

Maxime

Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Hi,

Ah ok, I somehow missed that reply, a pwm patch to add the compatibles
+ v3 of the dts patches is coming up.

Regards,

Hans