dt-bindings: pinctrl: qcom: Add msm8226 pinctrl bindings

Add device tree binding Documentation details for Qualcomm msm8226
pinctrl driver.

- Bindings documentation was based on qcom,ipq6018-pinctrl.yaml added by
  Sricharan R <sricharan@codeaurora.org> and then modified for msm8226
  content
Signed-off-by: Bartosz Dudziak <bartosz.dudziak@snejp.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200716205530.22910-2-bartosz.dudziak@snejp.plSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,msm8226-pinctrl.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/qcom,msm8226-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Technologies, Inc. MSM8226 TLMM block
+
+maintainers:
+  - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+description: |
+  This binding describes the Top Level Mode Multiplexer block found in the
+  MSM8226 platform.
+
+properties:
+  compatible:
+    const: qcom,msm8226-pinctrl
+
+  reg:
+    description: Specifies the base address and size of the TLMM register space
+    maxItems: 1
+
+  interrupts:
+    description: Specifies the TLMM summary IRQ
+    maxItems: 1
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    description: Specifies the PIN numbers and Flags, as defined in
+      include/dt-bindings/interrupt-controller/irq.h
+    const: 2
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    description: Specifying the pin number and flags, as defined in
+      include/dt-bindings/gpio/gpio.h
+    const: 2
+
+  gpio-ranges:
+    maxItems: 1
+
+  gpio-reserved-ranges:
+    maxItems: 1
+
+#PIN CONFIGURATION NODES
+patternProperties:
+  '-pins$':
+    type: object
+    description:
+      Pinctrl node's client devices use subnodes for desired pin configuration.
+      Client device subnodes use below standard properties.
+    $ref: "/schemas/pinctrl/pincfg-node.yaml"
+
+    properties:
+      pins:
+        description:
+          List of gpio pins affected by the properties specified in this
+          subnode.
+        items:
+          oneOf:
+            - pattern: "^gpio([0-9]|[1-9][0-9]|1[0-1][0-6])$"
+            - enum: [ sdc1_clk, sdc1_cmd, sdc1_data, sdc2_clk, sdc2_cmd, sdc2_data ]
+        minItems: 1
+        maxItems: 36
+
+      function:
+        description:
+          Specify the alternative function to be configured for the specified
+          pins. Functions are only valid for gpio pins.
+        enum: [ gpio, cci_i2c0, blsp_uim1, blsp_uim2, blsp_uim3, blsp_uim5,
+          blsp_i2c1, blsp_i2c2, blsp_i2c3, blsp_i2c5, blsp_spi1,
+          blsp_spi2, blsp_spi3, blsp_spi5, blsp_uart1, blsp_uart2,
+          blsp_uart3, blsp_uart5, cam_mclk0, cam_mclk1, wlan ]
+
+      drive-strength:
+        enum: [2, 4, 6, 8, 10, 12, 14, 16]
+        default: 2
+        description:
+          Selects the drive strength for the specified pins, in mA.
+
+      bias-pull-down: true
+
+      bias-pull-up: true
+
+      bias-disable: true
+
+      output-high: true
+
+      output-low: true
+
+    required:
+      - pins
+      - function
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - '#interrupt-cells'
+  - gpio-controller
+  - '#gpio-cells'
+  - gpio-ranges
+
+additionalProperties: false
+
+examples:
+  - |
+        #include <dt-bindings/interrupt-controller/arm-gic.h>
+        msmgpio: pinctrl@fd510000 {
+                compatible = "qcom,msm8226-pinctrl";
+                reg = <0xfd510000 0x4000>;
+
+                gpio-controller;
+                #gpio-cells = <2>;
+                gpio-ranges = <&msmgpio 0 0 117>;
+                interrupt-controller;
+                #interrupt-cells = <2>;
+                interrupts = <GIC_SPI 208 IRQ_TYPE_LEVEL_HIGH>;
+
+                serial-pins {
+                        pins = "gpio8", "gpio9";
+                        function = "blsp_uart3";
+                        drive-strength = <8>;
+                        bias-disable;
+                };
+        };