dt: Document Qualcomm APQ8084 pinctrl binding

Define a new binding for the Qualcomm TLMM (Top-Level Mode Mux) based pin
controller inside the APQ8084.
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Georgi Djakov <gdjakov@mm-sol.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,apq8084-pinctrl.txt

+Qualcomm APQ8084 TLMM block
+
+This binding describes the Top Level Mode Multiplexer block found in the
+MSM8960 platform.
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be "qcom,apq8084-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 abitrary 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-gpio146,
+		    sdc1_clk,
+		    sdc1_cmd,
+		    sdc1_data
+		    sdc2_clk,
+		    sdc2_cmd,
+		    sdc2_data
+
+- function:
+	Usage: required
+	Value type: <string>
+	Definition: Specify the alternative function to be configured for the
+		    specified pins. Functions are only valid for gpio pins.
+		    Valid values are:
+		    adsp_ext, audio_ref, blsp_i2c1, blsp_i2c2, blsp_i2c3,
+		    blsp_i2c4, blsp_i2c5, blsp_i2c6, blsp_i2c7, blsp_i2c8,
+		    blsp_i2c9, blsp_i2c10, blsp_i2c11, blsp_i2c12,
+		    blsp_spi1, blsp_spi2, blsp_spi3, blsp_spi4, blsp_spi5,
+		    blsp_spi6, blsp_spi7, blsp_spi8, blsp_spi9, blsp_spi10,
+		    blsp_spi11, blsp_spi12, blsp_uart1, blsp_uart2, blsp_uart3,
+		    blsp_uart4, blsp_uart5, blsp_uart6, blsp_uart7, blsp_uart8,
+		    blsp_uart9, blsp_uart10, blsp_uart11, blsp_uart12,
+		    blsp_uim1, blsp_uim2, blsp_uim3, blsp_uim4, blsp_uim5,
+		    blsp_uim6, blsp_uim7, blsp_uim8, blsp_uim9, blsp_uim10,
+		    blsp_uim11, blsp_uim12, cam_mclk0, cam_mclk1, cam_mclk2,
+		    cam_mclk3, cci_async, cci_async_in0, cci_i2c0, cci_i2c1,
+		    cci_timer0, cci_timer1, cci_timer2, cci_timer3, cci_timer4,
+		    edp_hpd, gcc_gp1, gcc_gp2, gcc_gp3, gcc_obt, gcc_vtt,i
+		    gp_mn, gp_pdm0, gp_pdm1, gp_pdm2, gp0_clk, gp1_clk, gpio,
+		    hdmi_cec, hdmi_ddc, hdmi_dtest, hdmi_hpd, hdmi_rcv, hsic,
+		    ldo_en, ldo_update, mdp_vsync, pci_e0, pci_e0_n, pci_e0_rst,
+		    pci_e1, pci_e1_rst, pci_e1_rst_n, pci_e1_clkreq_n, pri_mi2s,
+		    qua_mi2s, sata_act, sata_devsleep, sata_devsleep_n,
+		    sd_write, sdc_emmc_mode, sdc3, sdc4, sec_mi2s, slimbus,
+		    spdif_tx, spkr_i2s, spkr_i2s_ws, spss_geni, ter_mi2s, tsif1,
+		    tsif2, uim, uim_batt_alarm
+
+- 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.
+		    Not valid for sdc pins.
+
+- output-low:
+	Usage: optional
+	Value type: <none>
+	Definition: The specified pins are configured in output mode, driven
+		    low.
+		    Not valid for sdc pins.
+
+- 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:
+
+	tlmm: pinctrl@fd510000 {
+		compatible = "qcom,apq8084-pinctrl";
+		reg = <0xfd510000 0x4000>;
+
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		interrupts = <0 208 0>;
+
+		uart2: uart2-default {
+			mux {
+				pins = "gpio4", "gpio5";
+				function = "blsp_uart2";
+			};
+
+			tx {
+				pins = "gpio4";
+				drive-strength = <4>;
+				bias-disable;
+			};
+
+			rx {
+				pins = "gpio5";
+				drive-strength = <2>;
+				bias-pull-up;
+			};
+		};
+	};