dt-bindings: pinctrl: Add MDM9615 TLMM bindings

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Björn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,mdm9615-pinctrl.txt

+Qualcomm MDM9615 TLMM block
+
+This binding describes the Top Level Mode Multiplexer block found in the
+MDM9615 platform.
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be "qcom,mdm9615-pinctrl"
+
+- reg:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: the base address and size of the TLMM register space.
+
+- interrupts:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify the TLMM summary IRQ.
+
+- interrupt-controller:
+	Usage: required
+	Value type: <none>
+	Definition: identifies this node as an interrupt controller
+
+- #interrupt-cells:
+	Usage: required
+	Value type: <u32>
+	Definition: must be 2. Specifying the pin number and flags, as defined
+		    in <dt-bindings/interrupt-controller/irq.h>
+
+- gpio-controller:
+	Usage: required
+	Value type: <none>
+	Definition: identifies this node as a gpio controller
+
+- #gpio-cells:
+	Usage: required
+	Value type: <u32>
+	Definition: must be 2. Specifying the pin number and flags, as defined
+		    in <dt-bindings/gpio/gpio.h>
+
+Please refer to ../gpio/gpio.txt and ../interrupt-controller/interrupts.txt for
+a general description of GPIO and interrupt bindings.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices, including the meaning of the
+phrase "pin configuration node".
+
+The pin configuration nodes act as a container for an arbitrary number of
+subnodes. Each of these subnodes represents some desired configuration for a
+pin, a group, or a list of pins or groups. This configuration can include the
+mux function to select on those pin(s)/group(s), and various pin configuration
+parameters, such as pull-up, drive strength, etc.
+
+
+PIN CONFIGURATION NODES:
+
+The name of each subnode is not important; all subnodes should be enumerated
+and processed purely based on their content.
+
+Each subnode only affects those parameters that are explicitly listed. In
+other words, a subnode that lists a mux function but no pin configuration
+parameters implies no information about any pin configuration parameters.
+Similarly, a pin subnode that describes a pullup parameter implies no
+information about e.g. the mux function.
+
+
+The following generic properties as defined in pinctrl-bindings.txt are valid
+to specify in a pin configuration subnode:
+
+- pins:
+	Usage: required
+	Value type: <string-array>
+	Definition: List of gpio pins affected by the properties specified in
+		    this subnode.  Valid pins are:
+		    gpio0-gpio87
+
+- function:
+	Usage: required
+	Value type: <string>
+	Definition: Specify the alternative function to be configured for the
+		    specified pins.
+		    Valid values are:
+		    gpio, gsbi2_i2c, gsbi3, gsbi4, gsbi5_i2c, gsbi5_uart,
+		    sdc2, ebi2_lcdc, ps_hold, prim_audio, sec_audio,
+		    cdc_mclk
+
+- bias-disable:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins should be configued as no pull.
+
+- bias-pull-down:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins should be configued as pull down.
+
+- bias-pull-up:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins should be configued as pull up.
+
+- output-high:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins are configured in output mode, driven
+		    high.
+
+- output-low:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins are configured in output mode, driven
+		    low.
+
+- drive-strength:
+	Usage: optional
+	Value type: <u32>
+	Definition: Selects the drive strength for the specified pins, in mA.
+		    Valid values are: 2, 4, 6, 8, 10, 12, 14 and 16
+
+Example:
+
+	msmgpio: pinctrl@800000 {
+		compatible = "qcom,mdm9615-pinctrl";
+		reg = <0x800000 0x4000>;
+
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		interrupts = <0 16 0x4>;
+
+		gsbi8_uart: gsbi8-uart {
+			mux {
+				pins = "gpio34", "gpio35";
+				function = "gsbi8";
+			};
+
+			tx {
+				pins = "gpio34";
+				drive-strength = <4>;
+				bias-disable;
+			};
+
+			rx {
+				pins = "gpio35";
+				drive-strength = <2>;
+				bias-pull-up;
+			};
+		};
+	};