dt: Document Tegra20/30 pinctrl binding

Define a new binding for the Tegra pin controller, which is capable of
defining all aspects of desired pin multiplexing and pin configuration.
This is all based on the new common pinctrl bindings.

Add Tegra30 binding based on Tegra20 binding.

Add some basic stuff that was missing before:
* How many and what reg property entries must be provided.
* An example.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NDong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/nvidia,tegra20-pinmux.txt

-NVIDIA Tegra 2 pinmux controller
+NVIDIA Tegra20 pinmux controller
 
 Required properties:
-- compatible : "nvidia,tegra20-pinmux"
+- compatible: "nvidia,tegra20-pinmux"
+- reg: Should contain the register physical address and length for each of
+  the tri-state, mux, pull-up/down, and pad control register sets.
 
+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".
+
+Tegra's 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, tristate, drive strength, etc.
+
+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 or tristate parameter. For this
+reason, even seemingly boolean values are actually tristates in this binding:
+unspecified, off, or on. Unspecified is represented as an absent property,
+and off/on are represented as integer values 0 and 1.
+
+Required subnode-properties:
+- nvidia,pins : An array of strings. Each string contains the name of a pin or
+    group. Valid values for these names are listed below.
+
+Optional subnode-properties:
+- nvidia,function: A string containing the name of the function to mux to the
+  pin or group. Valid values for function names are listed below. See the Tegra
+  TRM to determine which are valid for each pin or group.
+- nvidia,pull: Integer, representing the pull-down/up to apply to the pin.
+    0: none, 1: down, 2: up.
+- nvidia,tristate: Integer.
+    0: drive, 1: tristate.
+- nvidia,high-speed-mode: Integer. Enable high speed mode the pins.
+    0: no, 1: yes.
+- nvidia,schmitt: Integer. Enables Schmitt Trigger on the input.
+    0: no, 1: yes.
+- nvidia,low-power-mode: Integer. Valid values 0-3. 0 is least power, 3 is
+    most power. Controls the drive power or current. See "Low Power Mode"
+    or "LPMD1" and "LPMD0" in the Tegra TRM.
+- nvidia,pull-down-strength: Integer. Controls drive strength. 0 is weakest.
+    The range of valid values depends on the pingroup. See "CAL_DRVDN" in the
+    Tegra TRM.
+- nvidia,pull-up-strength: Integer. Controls drive strength. 0 is weakest.
+    The range of valid values depends on the pingroup. See "CAL_DRVUP" in the
+    Tegra TRM.
+- nvidia,slew-rate-rising: Integer. Controls rising signal slew rate. 0 is
+    fastest. The range of valid values depends on the pingroup. See
+    "DRVDN_SLWR" in the Tegra TRM.
+- nvidia,slew-rate-falling: Integer. Controls falling signal slew rate. 0 is
+    fastest. The range of valid values depends on the pingroup. See
+    "DRVUP_SLWF" in the Tegra TRM.
+
+Note that many of these properties are only valid for certain specific pins
+or groups. See the Tegra TRM and various pinmux spreadsheets for complete
+details regarding which groups support which functionality. The Linux pinctrl
+driver may also be a useful reference, since it consolidates, disambiguates,
+and corrects data from all those sources.
+
+Valid values for pin and group names are:
+
+  mux groups:
+
+    These all support nvidia,function, nvidia,tristate, and many support
+    nvidia,pull.
+
+    ata, atb, atc, atd, ate, cdev1, cdev2, crtp, csus, dap1, dap2, dap3, dap4,
+    ddc, dta, dtb, dtc, dtd, dte, dtf, gma, gmb, gmc, gmd, gme, gpu, gpu7,
+    gpv, hdint, i2cp, irrx, irtx, kbca, kbcb, kbcc, kbcd, kbce, kbcf, lcsn,
+    ld0, ld1, ld2, ld3, ld4, ld5, ld6, ld7, ld8, ld9, ld10, ld11, ld12, ld13,
+    ld14, ld15, ld16, ld17, ldc, ldi, lhp0, lhp1, lhp2, lhs, lm0, lm1, lpp,
+    lpw0, lpw1, lpw2, lsc0, lsc1, lsck, lsda, lsdi, lspi, lvp0, lvp1, lvs,
+    owc, pmc, pta, rm, sdb, sdc, sdd, sdio1, slxa, slxc, slxd, slxk, spdi,
+    spdo, spia, spib, spic, spid, spie, spif, spig, spih, uaa, uab, uac, uad,
+    uca, ucb, uda.
+
+  tristate groups:
+
+    These only support nvidia,pull.
+
+    ck32, ddrc, pmca, pmcb, pmcc, pmcd, pmce, xm2c, xm2d, ls, lc, ld17_0,
+    ld19_18, ld21_20, ld23_22.
+
+  drive groups:
+
+    With some exceptions, these support nvidia,high-speed-mode,
+    nvidia,schmitt, nvidia,low-power-mode, nvidia,pull-down-strength,
+    nvidia,pull-up-strength, nvidia,slew_rate-rising, nvidia,slew_rate-falling.
+
+    drive_ao1, drive_ao2, drive_at1, drive_at2, drive_cdev1, drive_cdev2,
+    drive_csus, drive_dap1, drive_dap2, drive_dap3, drive_dap4, drive_dbg,
+    drive_lcd1, drive_lcd2, drive_sdmmc2, drive_sdmmc3, drive_spi, drive_uaa,
+    drive_uab, drive_uart2, drive_uart3, drive_vi1, drive_vi2, drive_xm2a,
+    drive_xm2c, drive_xm2d, drive_xm2clk, drive_sdio1, drive_crt, drive_ddc,
+    drive_gma, drive_gmb, drive_gmc, drive_gmd, drive_gme, drive_owr,
+    drive_uda.
+
+Example:
+
+	pinctrl@70000000 {
+		compatible = "nvidia,tegra20-pinmux";
+		reg = < 0x70000014 0x10    /* Tri-state registers */
+			0x70000080 0x20    /* Mux registers */
+			0x700000a0 0x14    /* Pull-up/down registers */
+			0x70000868 0xa8 >; /* Pad control registers */
+	};
+
+Example board file extract:
+
+	pinctrl@70000000 {
+		sdio4_default: sdio4_default {
+			atb {
+				nvidia,pins = "atb", "gma", "gme";
+				nvidia,function = "sdio4";
+				nvidia,pull = <0>;
+				nvidia,tristate = <0>;
+			};
+		};
+	};
+
+	sdhci@c8000600 {
+		pinctrl-names = "default";
+		pinctrl-0 = <&sdio4_default>;
+	};

Documentation/devicetree/bindings/pinctrl/nvidia,tegra30-pinmux.txt

+NVIDIA Tegra30 pinmux controller
+
+The Tegra30 pinctrl binding is very similar to the Tegra20 pinctrl binding,
+as described in nvidia,tegra20-pinmux.txt. In fact, this document assumes
+that binding as a baseline, and only documents the differences between the
+two bindings.
+
+Required properties:
+- compatible: "nvidia,tegra30-pinmux"
+- reg: Should contain the register physical address and length for each of
+  the pad control and mux registers.
+
+Tegra30 adds the following optional properties for pin configuration subnodes:
+- nvidia,enable-input: Integer. Enable the pin's input path. 0: no, 1: yes.
+- nvidia,open-drain: Integer. Enable open drain mode. 0: no, 1: yes.
+- nvidia,lock: Integer. Lock the pin configuration against further changes
+    until reset. 0: no, 1: yes.
+- nvidia,io-reset: Integer. Reset the IO path. 0: no, 1: yes.
+
+As with Tegra20, see the Tegra TRM for complete details regarding which groups
+support which functionality.
+
+Valid values for pin and group names are:
+
+  per-pin mux groups:
+
+    These all support nvidia,function, nvidia,tristate, nvidia,pull,
+    nvidia,enable-input, nvidia,lock. Some support nvidia,open-drain,
+    nvidia,io-reset.
+
+    clk_32k_out_pa0, uart3_cts_n_pa1, dap2_fs_pa2, dap2_sclk_pa3,
+    dap2_din_pa4, dap2_dout_pa5, sdmmc3_clk_pa6, sdmmc3_cmd_pa7, gmi_a17_pb0,
+    gmi_a18_pb1, lcd_pwr0_pb2, lcd_pclk_pb3, sdmmc3_dat3_pb4, sdmmc3_dat2_pb5,
+    sdmmc3_dat1_pb6, sdmmc3_dat0_pb7, uart3_rts_n_pc0, lcd_pwr1_pc1,
+    uart2_txd_pc2, uart2_rxd_pc3, gen1_i2c_scl_pc4, gen1_i2c_sda_pc5,
+    lcd_pwr2_pc6, gmi_wp_n_pc7, sdmmc3_dat5_pd0, sdmmc3_dat4_pd1, lcd_dc1_pd2,
+    sdmmc3_dat6_pd3, sdmmc3_dat7_pd4, vi_d1_pd5, vi_vsync_pd6, vi_hsync_pd7,
+    lcd_d0_pe0, lcd_d1_pe1, lcd_d2_pe2, lcd_d3_pe3, lcd_d4_pe4, lcd_d5_pe5,
+    lcd_d6_pe6, lcd_d7_pe7, lcd_d8_pf0, lcd_d9_pf1, lcd_d10_pf2, lcd_d11_pf3,
+    lcd_d12_pf4, lcd_d13_pf5, lcd_d14_pf6, lcd_d15_pf7, gmi_ad0_pg0,
+    gmi_ad1_pg1, gmi_ad2_pg2, gmi_ad3_pg3, gmi_ad4_pg4, gmi_ad5_pg5,
+    gmi_ad6_pg6, gmi_ad7_pg7, gmi_ad8_ph0, gmi_ad9_ph1, gmi_ad10_ph2,
+    gmi_ad11_ph3, gmi_ad12_ph4, gmi_ad13_ph5, gmi_ad14_ph6, gmi_ad15_ph7,
+    gmi_wr_n_pi0, gmi_oe_n_pi1, gmi_dqs_pi2, gmi_cs6_n_pi3, gmi_rst_n_pi4,
+    gmi_iordy_pi5, gmi_cs7_n_pi6, gmi_wait_pi7, gmi_cs0_n_pj0, lcd_de_pj1,
+    gmi_cs1_n_pj2, lcd_hsync_pj3, lcd_vsync_pj4, uart2_cts_n_pj5,
+    uart2_rts_n_pj6, gmi_a16_pj7, gmi_adv_n_pk0, gmi_clk_pk1, gmi_cs4_n_pk2,
+    gmi_cs2_n_pk3, gmi_cs3_n_pk4, spdif_out_pk5, spdif_in_pk6, gmi_a19_pk7,
+    vi_d2_pl0, vi_d3_pl1, vi_d4_pl2, vi_d5_pl3, vi_d6_pl4, vi_d7_pl5,
+    vi_d8_pl6, vi_d9_pl7, lcd_d16_pm0, lcd_d17_pm1, lcd_d18_pm2, lcd_d19_pm3,
+    lcd_d20_pm4, lcd_d21_pm5, lcd_d22_pm6, lcd_d23_pm7, dap1_fs_pn0,
+    dap1_din_pn1, dap1_dout_pn2, dap1_sclk_pn3, lcd_cs0_n_pn4, lcd_sdout_pn5,
+    lcd_dc0_pn6, hdmi_int_pn7, ulpi_data7_po0, ulpi_data0_po1, ulpi_data1_po2,
+    ulpi_data2_po3, ulpi_data3_po4, ulpi_data4_po5, ulpi_data5_po6,
+    ulpi_data6_po7, dap3_fs_pp0, dap3_din_pp1, dap3_dout_pp2, dap3_sclk_pp3,
+    dap4_fs_pp4, dap4_din_pp5, dap4_dout_pp6, dap4_sclk_pp7, kb_col0_pq0,
+    kb_col1_pq1, kb_col2_pq2, kb_col3_pq3, kb_col4_pq4, kb_col5_pq5,
+    kb_col6_pq6, kb_col7_pq7, kb_row0_pr0, kb_row1_pr1, kb_row2_pr2,
+    kb_row3_pr3, kb_row4_pr4, kb_row5_pr5, kb_row6_pr6, kb_row7_pr7,
+    kb_row8_ps0, kb_row9_ps1, kb_row10_ps2, kb_row11_ps3, kb_row12_ps4,
+    kb_row13_ps5, kb_row14_ps6, kb_row15_ps7, vi_pclk_pt0, vi_mclk_pt1,
+    vi_d10_pt2, vi_d11_pt3, vi_d0_pt4, gen2_i2c_scl_pt5, gen2_i2c_sda_pt6,
+    sdmmc4_cmd_pt7, pu0, pu1, pu2, pu3, pu4, pu5, pu6, jtag_rtck_pu7, pv0,
+    pv1, pv2, pv3, ddc_scl_pv4, ddc_sda_pv5, crt_hsync_pv6, crt_vsync_pv7,
+    lcd_cs1_n_pw0, lcd_m1_pw1, spi2_cs1_n_pw2, spi2_cs2_n_pw3, clk1_out_pw4,
+    clk2_out_pw5, uart3_txd_pw6, uart3_rxd_pw7, spi2_mosi_px0, spi2_miso_px1,
+    spi2_sck_px2, spi2_cs0_n_px3, spi1_mosi_px4, spi1_sck_px5, spi1_cs0_n_px6,
+    spi1_miso_px7, ulpi_clk_py0, ulpi_dir_py1, ulpi_nxt_py2, ulpi_stp_py3,
+    sdmmc1_dat3_py4, sdmmc1_dat2_py5, sdmmc1_dat1_py6, sdmmc1_dat0_py7,
+    sdmmc1_clk_pz0, sdmmc1_cmd_pz1, lcd_sdin_pz2, lcd_wr_n_pz3, lcd_sck_pz4,
+    sys_clk_req_pz5, pwr_i2c_scl_pz6, pwr_i2c_sda_pz7, sdmmc4_dat0_paa0,
+    sdmmc4_dat1_paa1, sdmmc4_dat2_paa2, sdmmc4_dat3_paa3, sdmmc4_dat4_paa4,
+    sdmmc4_dat5_paa5, sdmmc4_dat6_paa6, sdmmc4_dat7_paa7, pbb0,
+    cam_i2c_scl_pbb1, cam_i2c_sda_pbb2, pbb3, pbb4, pbb5, pbb6, pbb7,
+    cam_mclk_pcc0, pcc1, pcc2, sdmmc4_rst_n_pcc3, sdmmc4_clk_pcc4,
+    clk2_req_pcc5, pex_l2_rst_n_pcc6, pex_l2_clkreq_n_pcc7,
+    pex_l0_prsnt_n_pdd0, pex_l0_rst_n_pdd1, pex_l0_clkreq_n_pdd2,
+    pex_wake_n_pdd3, pex_l1_prsnt_n_pdd4, pex_l1_rst_n_pdd5,
+    pex_l1_clkreq_n_pdd6, pex_l2_prsnt_n_pdd7, clk3_out_pee0, clk3_req_pee1,
+    clk1_req_pee2, hdmi_cec_pee3, clk_32k_in, core_pwr_req, cpu_pwr_req, owr,
+    pwr_int_n.
+
+  drive groups:
+
+    These all support nvidia,pull-down-strength, nvidia,pull-up-strength,
+    nvidia,slew_rate-rising, nvidia,slew_rate-falling. Most but not all
+    support nvidia,high-speed-mode, nvidia,schmitt, nvidia,low-power-mode.
+
+    ao1, ao2, at1, at2, at3, at4, at5, cdev1, cdev2, cec, crt, csus, dap1,
+    dap2, dap3, dap4, dbg, ddc, dev3, gma, gmb, gmc, gmd, gme, gmf, gmg,
+    gmh, gpv, lcd1, lcd2, owr, sdio1, sdio2, sdio3, spi, uaa, uab, uart2,
+    uart3, uda, vi1.
+
+Example:
+
+	pinctrl@70000000 {
+		compatible = "nvidia,tegra30-pinmux";
+		reg = < 0x70000868 0xd0     /* Pad control registers */
+			0x70003000 0x3e0 >; /* Mux registers */
+	};
+
+Example board file extract:
+
+	pinctrl@70000000 {
+		sdmmc4_default: pinmux {
+			sdmmc4_clk_pcc4 {
+				nvidia,pins =	"sdmmc4_clk_pcc4",
+						"sdmmc4_rst_n_pcc3";
+				nvidia,function = "sdmmc4";
+				nvidia,pull = <0>;
+				nvidia,tristate = <0>;
+			};
+			sdmmc4_dat0_paa0 {
+				nvidia,pins =	"sdmmc4_dat0_paa0",
+						"sdmmc4_dat1_paa1",
+						"sdmmc4_dat2_paa2",
+						"sdmmc4_dat3_paa3",
+						"sdmmc4_dat4_paa4",
+						"sdmmc4_dat5_paa5",
+						"sdmmc4_dat6_paa6",
+						"sdmmc4_dat7_paa7";
+				nvidia,function = "sdmmc4";
+				nvidia,pull = <2>;
+				nvidia,tristate = <0>;
+			};
+		};
+	};
+
+	sdhci@78000400 {
+		pinctrl-names = "default";
+		pinctrl-0 = <&sdmmc4_default>;
+	};