[PATCH v2] arm64: dts: mediatek: mt8188-geralt: Add MT6319 PMIC

[Chen-Yu Tsai <wenst@chromium.org>]

The Geralt design uses a MT6319 PMIC to power the big cores and LPDDR4X
DRAM.

Add a device node for it and hook up all the supplies. However do not
add cpu-supply properties for the big cores. Adding them without the
firmware fix mentioned below will likely cause CPU DVFS to stop working.

This change requires a firmware fix for the SPMI bus to read back
correctly. The required firmware version is 15842.175.0. This is
included in ChromeOS releases R150-16700.22.0 (available in Beta
channel as of writing or stable channel in mid-July) or
R151-16721.0.0 and later.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
Changes since v1:
- Dropped cpu-supply on CPU6 and CPU7
- Added comment about broken firmware and upgrade versions
---
 .../boot/dts/mediatek/mt8188-geralt.dtsi      | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
index f382f90c48f5..dee946309121 100644
--- a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
@@ -4,6 +4,8 @@
  */
 /dts-v1/;
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/spmi/spmi.h>
+
 #include "mt8188.dtsi"
 #include "mt6359.dtsi"
 
@@ -1156,6 +1158,14 @@ pins-bus {
 		};
 	};
 
+	spmi_pins: spmi-pins {
+		pins-bus {
+			pinmux = <PINMUX_GPIO175__FUNC_B0_SPMI_M_SCL>,
+				 <PINMUX_GPIO176__FUNC_B0_SPMI_M_SDA>;
+			bias-disable;
+		};
+	};
+
 	uart0_pins: uart0-pins {
 		pins-bus {
 			pinmux = <PINMUX_GPIO31__FUNC_O_UTXD0>,
@@ -1267,6 +1277,70 @@ &spi2 {
 	status = "okay";
 };
 
+&spmi {
+	pinctrl-names = "default";
+	pinctrl-0 = <&spmi_pins>;
+	#address-cells = <2>;
+	#size-cells = <0>;
+	status = "okay";
+
+	pmic@6 {
+		compatible = "mediatek,mt6319-regulator", "mediatek,mt6315-regulator";
+		reg = <0x6 SPMI_USID>;
+		pvdd1-supply = <&pp4200_s5>;
+		pvdd2-supply = <&pp4200_s5>;
+		pvdd3-supply = <&pp4200_s5>;
+		pvdd4-supply = <&pp4200_s5>;
+
+		regulators {
+			/*
+			 * vbuck1 is the cpu-supply for CPU6 and CPU7.
+			 *
+			 * However, this device originally shipped with a broken
+			 * firmware that causes register reads over SPMI fail.
+			 * This is fixed in firmware version 15842.175.0, which
+			 * is included in ChromeOS releases R150-16700.22.0 or
+			 * R151-16721.0.0 and later.
+			 *
+			 * Assigning the cpu-supply properties for CPU6 and CPU7
+			 * without the fix will likely cause CPU DVFS to stop
+			 * working. Hence the assignment is left out to avoid a
+			 * regression of the function. If the user is confident
+			 * that their system has the fix, they can added the
+			 * property themselves.
+			 */
+			mt6319_buck1: vbuck1 {
+					regulator-name = "ppvar_dvdd_proc_bc";
+					regulator-min-microvolt = <520000>;
+					regulator-max-microvolt = <1155000>;
+					regulator-enable-ramp-delay = <256>;
+					regulator-allowed-modes = <0 1 2>;
+					regulator-always-on;
+			};
+
+			/* vbuck2 is ganged with vbuck1 */
+
+			mt6319_buck3: vbuck3 {
+					regulator-name = "pp1125_emi_vdd2";
+					regulator-min-microvolt = <1060000>;
+					regulator-max-microvolt = <1170000>;
+					regulator-enable-ramp-delay = <256>;
+					regulator-allowed-modes = <0 1 2>;
+					regulator-always-on;
+			};
+
+			mt6319_buck4: vbuck4 {
+					regulator-name = "pp0600_emi_vddq";
+					regulator-min-microvolt = <570000>;
+					regulator-max-microvolt = <650000>;
+					regulator-enable-ramp-delay = <256>;
+					regulator-allowed-modes = <0 1 2>;
+					regulator-always-on;
+			};
+		};
+	};
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_pins>;
-- 
2.55.0.795.g602f6c329a-goog