[PATCH v4 1/4] dt-bindings: pinctrl: mt8183: add binding document
From: Zhiyong Tao
Date: Sun Mar 31 2019 - 23:35:58 EST
The commit adds mt8183 compatible node in binding document.
Signed-off-by: Zhiyong Tao <zhiyong.tao@xxxxxxxxxxxx>
Signed-off-by: Erin Lo <erin.lo@xxxxxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
---
This patch is based on patch "https://patchwork.kernel.org/patch/10778511/";.
---
.../devicetree/bindings/pinctrl/pinctrl-mt8183.txt | 132 +++++++++++++++++++++
1 file changed, 132 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
new file mode 100644
index 000000000000..eccbe3f55d3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
@@ -0,0 +1,132 @@
+* Mediatek MT8183 Pin Controller
+
+The Mediatek's Pin controller is used to control SoC pins.
+
+Required properties:
+- compatible: value should be one of the following.
+ "mediatek,mt8183-pinctrl", compatible with mt8183 pinctrl.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
+ binding is used, the amount of cells must be specified as 2. See the below
+ mentioned gpio binding representation for description of particular cells.
+- gpio-ranges : gpio valid number range.
+- reg: physical address base for gpio base registers. There are 10 GPIO
+ physical address base in mt8183.
+
+Optional properties:
+- reg-names: gpio base register names. There are 10 gpio base register
+ names in mt8183. They are "iocfg0", "iocfg1", "iocfg2", "iocfg3", "iocfg4",
+ "iocfg5", "iocfg6", "iocfg7", "iocfg8", "eint".
+- interrupt-controller: Marks the device node as an interrupt controller
+- #interrupt-cells: Should be two.
+- interrupts : The interrupt outputs to sysirq.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices.
+
+Subnode format
+A pinctrl node should contain at least one subnodes representing the
+pinctrl groups available on the machine. Each subnode will list the
+pins it needs, and how they should be configured, with regard to muxer
+configuration, pullups, drive strength, input enable/disable and input schmitt.
+
+ node {
+ pinmux = <PIN_NUMBER_PINMUX>;
+ GENERIC_PINCONFIG;
+ };
+
+Required properties:
+- pinmux: integer array, represents gpio pin number and mux setting.
+ Supported pin number and mux varies for different SoCs, and are defined
+ as macros in boot/dts/<soc>-pinfunc.h directly.
+
+Optional properties:
+- GENERIC_PINCONFIG: is the generic pinconfig options to use, bias-disable,
+ bias-pull-down, bias-pull-up, input-enable, input-disable, output-low,
+ output-high, input-schmitt-enable, input-schmitt-disable
+ and drive-strength are valid.
+
+ Some special pins have extra pull up strength, there are R0 and R1 pull-up
+ resistors available, but for user, it's only need to set R1R0 as 00, 01,
+ 10 or 11. So It needs config "mediatek,pull-up-adv" or
+ "mediatek,pull-down-adv" to support arguments for those special pins.
+ Valid arguments are from 0 to 3.
+
+ mediatek,tdsel: An integer describing the steps for output level shifter
+ duty cycle when asserted (high pulse width adjustment). Valid arguments
+ are from 0 to 15.
+ mediatek,rdsel: An integer describing the steps for input level shifter
+ duty cycle when asserted (high pulse width adjustment). Valid arguments
+ are from 0 to 63.
+
+ When config drive-strength, it can support some arguments, such as
+ MTK_DRIVE_4mA, MTK_DRIVE_6mA, etc. See dt-bindings/pinctrl/mt65xx.h.
+ It can only support 2/4/6/8/10/12/14/16mA in mt8183.
+ For I2C pins, there are existing generic driving setup and the specific
+ driving setup. I2C pins can only support 2/4/6/8/10/12/14/16mA driving
+ adjustment in generic driving setup. But in specific driving setup,
+ they can support 0.125/0.25/0.5/1mA adjustment. If we enable specific
+ driving setup for I2C pins, the existing generic driving setup will be
+ disabled. For some special features, we need the I2C pins specific
+ driving setup. The specific driving setup is controlled by E1E0EN.
+ So we need add extra vendor driving preperty instead of
+ the generic driving property.
+ We can add "mediatek,drive-strength-adv = <XXX>;" to describe the specific
+ driving setup property. "XXX" means the value of E1E0EN. EN is 0 or 1.
+ It is used to enable or disable the specific driving setup.
+ E1E0 is used to describe the detail strength specification of the I2C pin.
+ When E1=0/E0=0, the strength is 0.125mA.
+ When E1=0/E0=1, the strength is 0.25mA.
+ When E1=1/E0=0, the strength is 0.5mA.
+ When E1=1/E0=1, the strength is 1mA.
+ So the valid arguments of "mediatek,drive-strength-adv" are from 0 to 7.
+
+Examples:
+
+#include "mt8183-pinfunc.h"
+
+...
+{
+ pio: pinctrl@10005000 {
+ compatible = "mediatek,mt8183-pinctrl";
+ reg = <0 0x10005000 0 0x1000>,
+ <0 0x11f20000 0 0x1000>,
+ <0 0x11e80000 0 0x1000>,
+ <0 0x11e70000 0 0x1000>,
+ <0 0x11e90000 0 0x1000>,
+ <0 0x11d30000 0 0x1000>,
+ <0 0x11d20000 0 0x1000>,
+ <0 0x11c50000 0 0x1000>,
+ <0 0x11f30000 0 0x1000>,
+ <0 0x1000b000 0 0x1000>;
+ reg-names = "iocfg0", "iocfg1", "iocfg2",
+ "iocfg3", "iocfg4", "iocfg5",
+ "iocfg6", "iocfg7", "iocfg8",
+ "eint";
+ gpio-controller;
+ #gpio-cells = <2>;
+ gpio-ranges = <&pio 0 0 192>;
+ interrupt-controller;
+ interrupts = <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>;
+ #interrupt-cells = <2>;
+
+ i2c0_pins_a: i2c0 {
+ pins1 {
+ pinmux = <PINMUX_GPIO48__FUNC_SCL5>,
+ <PINMUX_GPIO49__FUNC_SDA5>;
+ mediatek,pull-up-adv = <3>;
+ mediatek,drive-strength-adv = <7>;
+ };
+ };
+
+ i2c1_pins_a: i2c1 {
+ pins {
+ pinmux = <PINMUX_GPIO50__FUNC_SCL3>,
+ <PINMUX_GPIO51__FUNC_SDA3>;
+ mediatek,pull-down-adv = <2>;
+ mediatek,drive-strength-adv = <4>;
+ };
+ };
+ ...
+ };
+};
--
2.12.5