arm64: dts: Add a device tree for the Librem 5 phone

Add a devicetree description for the Librem 5 phone. 4 hardware revisions
have been available. Some revisions include changes that need different
software to be run. So far, r3 ("Dogwood") is one such example, see:

	"Aspen"		r0	not supported (very few devices exist)
	"Birch"		r1	supported by r2
	"Chestnut"	r2	added by this patch
	"Dogwood"	r3	added by this patch
	"Evergreen"	r4	tba / most likely supported by r3

See https://puri.sm/products/librem-5/ for more information.

This boots to a working console with working WWAN modem, wifi usdhc,
IMU sensor device, proximity sensor, haptic motor, gpio keys, GNSS and LEDs.
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com> (for the audio part)
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/Makefile

@@ -35,6 +35,8 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mp-evk.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-evk.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-hummingboard-pulse.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-librem5-devkit.dtb
+dtb-$(CONFIG_ARCH_MXC) += imx8mq-librem5-r2.dtb
+dtb-$(CONFIG_ARCH_MXC) += imx8mq-librem5-r3.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-nitrogen.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-phanbell.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mq-pico-pi.dtb

arch/arm64/boot/dts/freescale/imx8mq-librem5-r2.dts

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+// Copyright (C) 2020 Purism SPC <kernel@puri.sm>
+//
+// Librem 5 Chestnut
+
+/dts-v1/;
+
+#include "imx8mq-librem5.dtsi"
+
+/ {
+	model = "Purism Librem 5r2";
+	compatible = "purism,librem5r2", "purism,librem5", "fsl,imx8mq";
+};
+
+&bq25895 {
+	ti,battery-regulation-voltage = <4192000>; /* uV */
+	ti,charge-current = <1600000>; /* uA */
+	ti,termination-current = <66000>;  /* uA */
+};
+
+&accel_gyro {
+	mount-matrix =  "1",  "0",  "0",
+			"0", "-1",  "0",
+			"0",  "0",  "1";
+};
+
+&proximity {
+	proximity-near-level = <220>;
+};

arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+// Copyright (C) 2020 Purism SPC <kernel@puri.sm>
+
+/dts-v1/;
+
+#include "imx8mq-librem5.dtsi"
+
+/ {
+	model = "Purism Librem 5r3";
+	compatible = "purism,librem5r3", "purism,librem5", "fsl,imx8mq";
+};
+
+&accel_gyro {
+	mount-matrix =  "1",  "0",  "0",
+			"0",  "1",  "0",
+			"0",  "0", "-1";
+};
+
+&bq25895 {
+	ti,battery-regulation-voltage = <4200000>; /* uV */
+	ti,charge-current = <1500000>; /* uA */
+	ti,termination-current = <144000>;  /* uA */
+};
+
+&proximity {
+	proximity-near-level = <25>;
+};