soc: mediatek: Add PMIC wrapper for MT8135 and MT6397 SoC

This adds support for the PMIC wrapper found on MediaTek MT8135 and
MT8173 SoCs.

On MediaTek MT8135, MT8173 and other SoCs the PMIC is connected via
SPI. The SPI master interface is not directly visible to the CPU, but
only through the PMIC wrapper inside the SoC. The communication between
the SoC and the PMIC can optionally be encrypted. Also a non standard
Dual IO SPI mode can be used to increase speed. The MT8135 also supports
a special feature named "IP Pairing". With IP Pairing the pins of some
SoC internal peripherals can be on the PMIC. The signals of these pins
are routed over the SPI bus using the pwrap bridge. Because of these
optional non SPI conform features the PMIC driver is not implemented as
a SPI bus master driver.

Signed-off-by: Flora Fu, MediaTek
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 56 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/soc/mediatek/pwrap.txt b/Documentation/devicetree/bindings/soc/mediatek/pwrap.txt
new file mode 100644
index 000000000000..66cc5286f065
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/mediatek/pwrap.txt
@@ -0,0 +1,56 @@
+MediaTek PMIC Wrapper Driver
+
+This document describes the binding for the MediaTek PMIC wrapper.
+
+On MediaTek MT8135, MT8173 and other SoCs the PMIC is connected via
+SPI. The SPI master interface is not directly visible to the CPU, but
+only through the PMIC wrapper inside the SoC. The communication between
+the SoC and the PMIC can optionally be encrypted. Also a non standard
+Dual IO SPI mode can be used to increase speed.
+
+IP Pairing
+
+on MT8135 the pins of some SoC internal peripherals can be on the PMIC.
+The signals of these pins are routed over the SPI bus using the pwrap
+bridge. In the binding description below the properties needed for bridging
+are marked with "IP Pairing". These are optional on SoCs which do not support
+IP Pairing
+
+Required properties in pwrap device node.
+- compatible: "mediatek,mt8135-pwrap" or "mediatek,mt8173-pwrap"
+- interrupts: IRQ for pwrap in SOC
+- reg-names: Must include the following entries:
+  "pwrap": Main registers base
+  "pwrap-bridge": bridge base (IP Pairing)
+- reg: Must contain an entry for each entry in reg-names.
+- reset-names: Must include the following entries:
+  "pwrap"
+  "pwrap-bridge" (IP Pairing)
+- resets: Must contain an entry for each entry in reset-names.
+- clock-names: Must include the following entries:
+  "spi": SPI bus clock
+  "wrap": Main module clock
+- clocks: Must contain an entry for each entry in clock-names.
+
+Optional properities:
+- pmic: Mediatek PMIC MFD is the child device of pwrap
+  See the following for child node definitions:
+  Documentation/devicetree/bindings/mfd/mt6397.txt
+
+Example:
+	pwrap: pwrap@1000f000 {
+		compatible = "mediatek,mt8135-pwrap";
+		reg = <0 0x1000f000 0 0x1000>,
+			<0 0x11017000 0 0x1000>;
+		reg-names = "pwrap", "pwrap-bridge";
+		interrupts = <GIC_SPI 128 IRQ_TYPE_LEVEL_HIGH>;
+		resets = <&infracfg MT8135_INFRA_PMIC_WRAP_RST>,
+				<&pericfg MT8135_PERI_PWRAP_BRIDGE_SW_RST>;
+		reset-names = "pwrap", "pwrap-bridge";
+		clocks = <&clk26m>, <&clk26m>;
+		clock-names = "spi", "wrap";
+
+		pmic {
+			compatible = "mediatek,mt6397";
+		};
+	};