Enable the Netronix EC on the Kobo Aura ebook reader.

Several features are still missing:
 - Frontlight/backlight. The vendor kernel drives the frontlight LED
   using the PWM output of the EC and an additional boost pin that
   increases the brightness.
 - Battery monitoring
 - Interrupts for RTC alarm and low-battery events

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
---
v5-v9:
- no changes

v4:
- https://lore.kernel.org/lkml/20201123000913.1506944-1-j.neuschaefer@gmx.net/ (local)
- Add 'grp' suffix to pinctrl node

v3:
- Remove interrupt-controller property from embedded-controller node
- subnodes of embedded-controller node in to the main node

v2:
- Fix pwm-cells property (should be 2, not 1)
---
 arch/arm/boot/dts/imx50-kobo-aura.dts | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/imx50-kobo-aura.dts b/arch/arm/boot/dts/imx50-kobo-aura.dts
index 97cfd970fe742..82ce8c43be867 100644
--- a/arch/arm/boot/dts/imx50-kobo-aura.dts
+++ b/arch/arm/boot/dts/imx50-kobo-aura.dts

@@ -143,10 +143,24 @@ &i2c3 {
 	pinctrl-0 = <&pinctrl_i2c3>;
 	status = "okay";

-	/* TODO: embedded controller at 0x43 */
+	embedded-controller@43 {
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_ec>;
+		compatible = "netronix,ntxec";
+		reg = <0x43>;
+		system-power-controller;
+		interrupts-extended = <&gpio4 11 IRQ_TYPE_EDGE_FALLING>;
+		#pwm-cells = <2>;
+	};
 };

 &iomuxc {
+	pinctrl_ec: ecgrp {
+		fsl,pins = <
+			MX50_PAD_CSPI_SS0__GPIO4_11		0x0	/* INT */
+		>;
+	};
+
 	pinctrl_gpiokeys: gpiokeysgrp {
 		fsl,pins = <
 			MX50_PAD_CSPI_MISO__GPIO4_10		0x0
--

2.29.2