ARM: dts: AM33XX: Add PWM backlight DT data to am335x-evmsk

PWM output from ecap2 uses as backlight source. Also adds low threshold
value to have a uniform divisions in brightness-levels scales with
inverse polarity.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm/boot/dts/am335x-evmsk.dts b/arch/arm/boot/dts/am335x-evmsk.dts
index 338b68188349..2033a37c86ec 100644
--- a/arch/arm/boot/dts/am335x-evmsk.dts
+++ b/arch/arm/boot/dts/am335x-evmsk.dts
@@ -71,6 +71,12 @@
                                 0x1b4 (PIN_OUTPUT_PULLDOWN | MUX_MODE3)         /* xdma_event_intr1.clkout2 */
                         >;
                 };
+
+                ecap2_pins: backlight_pins {
+                        pinctrl-single,pins = <
+                                0x19c 0x4       /* mcasp0_ahclkr.ecap2_in_pwm2_out MODE4 */
+                        >;
+                };
         };
 
         ocp {
@@ -120,6 +126,16 @@
                                 st,max-limit-z = <750>;
                         };
                 };
+
+                epwmss2: epwmss@48304000 {
+                        status = "okay";
+
+                        ecap2: ecap@48304100 {
+                                status = "okay";
+                                pinctrl-names = "default";
+                                pinctrl-0 = <&ecap2_pins>;
+                        };
+                };
         };
 
         vbat: fixedregulator@0 {
@@ -199,6 +215,13 @@
                         gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>;
                 };
         };
+
+        backlight {
+                compatible = "pwm-backlight";
+                pwms = <&ecap2 0 50000 1>;
+                brightness-levels = <0 58 61 66 75 90 125 170 255>;
+                default-brightness-level = <8>;
+        };
 };
 
 #include "tps65910.dtsi"