DT: pinctrl: Document Qualcomm MSM8916 pinctrl binding

Qualcomm MSM8916 TLMM block

This binding describes the Top Level Mode Multiplexer block found in the

MSM8916 platform.

- compatible:

	Usage: required

	Value type: <string>

	Definition: must be "qcom,msm8916-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-gpio121,

		    sdc1_clk,

		    sdc1_cmd,

		    sdc1_data

		    sdc2_clk,

		    sdc2_cmd,

		    sdc2_data,

		    qdsd_cmd,

		    qdsd_data0,

		    qdsd_data1,

		    qdsd_data2,

		    qdsd_data3

- 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, alsp_int, atest_bbrx0, atest_bbrx1, atest_char, atest_char0,

	atest_char1, atest_char2, atest_char3, atest_combodac, atest_gpsadc0,

	atest_gpsadc1, atest_tsens, atest_wlan0, atest_wlan1, backlight_en,

	bimc_dte0,bimc_dte1, blsp_i2c1, blsp_i2c2, blsp_i2c3, blsp_i2c4,

	blsp_i2c5, blsp_i2c6, blsp_spi1, blsp_spi1_cs1, blsp_spi1_cs2,

	blsp_spi1_cs3, blsp_spi2, blsp_spi2_cs1, blsp_spi2_cs2, blsp_spi2_cs3,

	blsp_spi3, blsp_spi3_cs1, blsp_spi3_cs2, blsp_spi3_cs3, blsp_spi4,

	blsp_spi5, blsp_spi6, blsp_uart1, blsp_uart2, blsp_uim1, blsp_uim2,

	cam1_rst, cam1_standby, cam_mclk0, cam_mclk1, cci_async, cci_i2c,

	cci_timer0, cci_timer1, cci_timer2, cdc_pdm0, codec_mad, dbg_out,

	display_5v, dmic0_clk, dmic0_data, dsi_rst, ebi0_wrcdc, euro_us,

	ext_lpass, flash_strobe, gcc_gp1_clk_a, gcc_gp1_clk_b, gcc_gp2_clk_a,

	gcc_gp2_clk_b, gcc_gp3_clk_a, gcc_gp3_clk_b, gpio, gsm0_tx0, gsm0_tx1,

	gsm1_tx0, gsm1_tx1, gyro_accl, kpsns0, kpsns1, kpsns2, ldo_en,

	ldo_update, mag_int, mdp_vsync, modem_tsync, m_voc, nav_pps, nav_tsync,

	pa_indicator, pbs0, pbs1, pbs2, pri_mi2s, pri_mi2s_ws, prng_rosc,

	pwr_crypto_enabled_a, pwr_crypto_enabled_b, pwr_modem_enabled_a,

	pwr_modem_enabled_b, pwr_nav_enabled_a, pwr_nav_enabled_b,

	qdss_ctitrig_in_a0, qdss_ctitrig_in_a1, qdss_ctitrig_in_b0,

	qdss_ctitrig_in_b1, qdss_ctitrig_out_a0, qdss_ctitrig_out_a1,

	qdss_ctitrig_out_b0, qdss_ctitrig_out_b1, qdss_traceclk_a,

	qdss_traceclk_b, qdss_tracectl_a, qdss_tracectl_b, qdss_tracedata_a,

	qdss_tracedata_b, reset_n, sd_card, sd_write, sec_mi2s, smb_int,

	ssbi_wtr0, ssbi_wtr1, uim1, uim2, uim3, uim_batt, wcss_bt, wcss_fm,

	wcss_wlan, webcam1_rst

- 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@1000000 {

		compatible = "qcom,msm8916-pinctrl";

		reg = <0x1000000 0x300000>;

		interrupts = <0 208 0>;

		gpio-controller;

		#gpio-cells = <2>;

		interrupt-controller;

		#interrupt-cells = <2>;

		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;

			};

		};

	};