diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-03 18:48:03 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-03 18:48:03 (GMT) |
commit | 3dbde57ad941c55345fd7fac0ee3f70f204b02d8 (patch) | |
tree | 237c6de64d05da3f61b9ac1724e37a5c1f014b71 /Documentation | |
parent | a6e6d863cf68bba886acfe47dbdc8f245cce588f (diff) | |
parent | 2207a4e1ca6a1bb126360b6d0c236af6664532f2 (diff) | |
download | linux-3dbde57ad941c55345fd7fac0ee3f70f204b02d8.tar.xz |
Merge tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control changes from Linus Walleij:
- A large slew of improvements of the Genric pin configuration support,
and deployment in four different platforms: Rockchip, Super-H PFC,
ABx500 and TZ1090. Support BIAS_BUS_HOLD, get device tree parsing
and debugfs support into shape.
- We also have device tree support with generic naming conventions for
the generic pin configuration.
- Delete the unused and confusing direct pinconf API. Now state
transitions is *the* way to control pins and multiplexing.
- New drivers for Rockchip, TZ1090, and TZ1090 PDC.
- Two pin control states related to power management are now handled in
the device core: "sleep" and "idle", removing a lot of boilerplate
code in drivers. We do not yet know if this is the final word for
pin PM, but it already make things a lot easier to handle.
- Handle sparse GPIO ranges passing a list of disparate pins, and
utilize these in the new BayTrail (x86 Atom SoC) driver.
- Make the sunxi (AllWinner) driver handle external interrupts.
- Make it possible for pinctrl-single to handle the case where several
pins are managed by a single register, and augment it to handle sleep
modes.
- Cleanups and improvements for the abx500 drivers.
- Move Sirf pin control drivers to their own directory, support
save/restore of context and add support for the SiRFatlas6 SoC.
- PMU muxing for the Dove pinctrl driver.
- Finalization and support for VF610 in the i.MX6 pinctrl driver.
- Smoothen out various Exynos rough edges.
- Generic cleanups of various kinds.
* tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (82 commits)
pinctrl: vt8500: wmt: remove redundant dev_err call in wmt_pinctrl_probe()
pinctrl: remove bindings for pinconf options needing more thought
pinctrl: remove slew-rate parameter from tz1090
pinctrl: set unit for debounce time pinconfig to usec
pinctrl: more clarifications for generic pull configs
pinctrl: rip out the direct pinconf API
pinctrl-tz1090-pdc: add TZ1090 PDC pinctrl driver
pinctrl-tz1090: add TZ1090 pinctrl driver
pinctrl: samsung: Staticize drvdata_list
pinctrl: rockchip: Add missing irq_gc_unlock() call before return error
pinctrl: abx500: rework error path
pinctrl: abx500: suppress hardcoded value
pinctrl: abx500: factorize code
pinctrl: abx500: fix abx500_gpio_get()
pinctrl: abx500: fix abx500_pin_config_set()
pinctrl: abx500: Add device tree support
sh-pfc: Guard DT parsing with #ifdef CONFIG_OF
pinctrl: add Intel BayTrail GPIO/pinctrl support
pinctrl: fix pinconf_ops::pin_config_dbg_parse_modify kerneldoc
pinctrl: Staticize local symbols
...
Conflicts:
drivers/net/ethernet/ti/davinci_mdio.c
drivers/pinctrl/Makefile
Diffstat (limited to 'Documentation')
10 files changed, 1105 insertions, 31 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/fsl,vf610-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/fsl,vf610-pinctrl.txt new file mode 100644 index 0000000..ddcdeb6 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/fsl,vf610-pinctrl.txt @@ -0,0 +1,41 @@ +Freescale Vybrid VF610 IOMUX Controller + +Please refer to fsl,imx-pinctrl.txt in this directory for common binding part +and usage. + +Required properties: +- compatible: "fsl,vf610-iomuxc" +- fsl,pins: two integers array, represents a group of pins mux and config + setting. The format is fsl,pins = <PIN_FUNC_ID CONFIG>, PIN_FUNC_ID is + a pin working on a specific function, CONFIG is the pad setting value + such as pull-up, speed, ode for this pin. Please refer to Vybrid VF610 + datasheet for the valid pad config settings. + +CONFIG bits definition: +PAD_CTL_SPEED_LOW (1 << 12) +PAD_CTL_SPEED_MED (2 << 12) +PAD_CTL_SPEED_HIGH (3 << 12) +PAD_CTL_SRE_FAST (1 << 11) +PAD_CTL_SRE_SLOW (0 << 11) +PAD_CTL_ODE (1 << 10) +PAD_CTL_HYS (1 << 9) +PAD_CTL_DSE_DISABLE (0 << 6) +PAD_CTL_DSE_150ohm (1 << 6) +PAD_CTL_DSE_75ohm (2 << 6) +PAD_CTL_DSE_50ohm (3 << 6) +PAD_CTL_DSE_37ohm (4 << 6) +PAD_CTL_DSE_30ohm (5 << 6) +PAD_CTL_DSE_25ohm (6 << 6) +PAD_CTL_DSE_20ohm (7 << 6) +PAD_CTL_PUS_100K_DOWN (0 << 4) +PAD_CTL_PUS_47K_UP (1 << 4) +PAD_CTL_PUS_100K_UP (2 << 4) +PAD_CTL_PUS_22K_UP (3 << 4) +PAD_CTL_PKE (1 << 3) +PAD_CTL_PUE (1 << 2) +PAD_CTL_OBE_ENABLE (1 << 1) +PAD_CTL_IBE_ENABLE (1 << 0) +PAD_CTL_OBE_IBE_ENABLE (3 << 0) + +Please refer to vf610-pinfunc.h in device tree source folder +for all available PIN_FUNC_ID for Vybrid VF610. diff --git a/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt new file mode 100644 index 0000000..a186181 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt @@ -0,0 +1,127 @@ +ImgTec TZ1090 PDC pin controller + +Required properties: +- compatible: "img,tz1090-pdc-pinctrl" +- reg: Should contain the register physical address and length of the + SOC_GPIO_CONTROL registers in the PDC register region. + +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". + +TZ1090-PDC'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, 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. 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: +- tz1090,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: +- tz1090,function: A string containing the name of the function to mux to the + pin or group. Valid values for function names are listed below, including + which pingroups can be muxed to them. +- supported generic pinconfig properties (for further details see + Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt): + - bias-disable + - bias-high-impedance + - bias-bus-hold + - bias-pull-up + - bias-pull-down + - input-schmitt-enable + - input-schmitt-disable + - drive-strength: Integer, control drive strength of pins in mA. + 2: 2mA + 4: 4mA + 8: 8mA + 12: 12mA + - low-power-enable: Flag, power-on-start weak pull-down for invalid power. + - low-power-disable: Flag, power-on-start weak pull-down disabled. + +Note that many of these properties are only valid for certain specific pins +or groups. See the TZ1090 TRM for complete details regarding which groups +support which functionality. The Linux pinctrl driver may also be a useful +reference. + +Valid values for pin and group names are: + + pins: + + These all support bias-high-impediance, bias-pull-up, bias-pull-down, and + bias-bus-hold (which can also be provided to any of the groups below to set + it for all gpio pins in that group). + + gpio0, gpio1, sys_wake0, sys_wake1, sys_wake2, ir_data, ext_power. + + mux groups: + + These all support function. + + gpio0 + pins: gpio0. + function: ir_mod_stable_out. + gpio1 + pins: gpio1. + function: ir_mod_power_out. + + drive groups: + + These support input-schmitt-enable, input-schmitt-disable, + drive-strength, low-power-enable, and low-power-disable. + + pdc + pins: gpio0, gpio1, sys_wake0, sys_wake1, sys_wake2, ir_data, + ext_power. + +Example: + + pinctrl_pdc: pinctrl@02006500 { + #gpio-range-cells = <3>; + compatible = "img,tz1090-pdc-pinctrl"; + reg = <0x02006500 0x100>; + }; + +Example board file extracts: + + &pinctrl_pdc { + pinctrl-names = "default"; + pinctrl-0 = <&syswake_default>; + + syswake_default: syswakes { + syswake_cfg { + tz1090,pins = "sys_wake0", + "sys_wake1", + "sys_wake2"; + pull-up; + }; + }; + irmod_default: irmod { + gpio0_cfg { + tz1090,pins = "gpio0"; + tz1090,function = "ir_mod_stable_out"; + }; + gpio1_cfg { + tz1090,pins = "gpio1"; + tz1090,function = "ir_mod_power_out"; + }; + }; + }; + + ir: ir@02006200 { + pinctrl-names = "default"; + pinctrl-0 = <&irmod_default>; + }; diff --git a/Documentation/devicetree/bindings/pinctrl/img,tz1090-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pinctrl.txt new file mode 100644 index 0000000..4b27c99 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pinctrl.txt @@ -0,0 +1,227 @@ +ImgTec TZ1090 pin controller + +Required properties: +- compatible: "img,tz1090-pinctrl" +- reg: Should contain the register physical address and length of the pad + configuration registers (CR_PADS_* and CR_IF_CTL0). + +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". + +TZ1090'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, 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. 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: +- tz1090,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: +- tz1090,function: A string containing the name of the function to mux to the + pin or group. Valid values for function names are listed below, including + which pingroups can be muxed to them. +- supported generic pinconfig properties (for further details see + Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt): + - bias-disable + - bias-high-impedance + - bias-bus-hold + - bias-pull-up + - bias-pull-down + - input-schmitt-enable + - input-schmitt-disable + - drive-strength: Integer, control drive strength of pins in mA. + 2: 2mA + 4: 4mA + 8: 8mA + 12: 12mA + + +Note that many of these properties are only valid for certain specific pins +or groups. See the TZ1090 TRM for complete details regarding which groups +support which functionality. The Linux pinctrl driver may also be a useful +reference. + +Valid values for pin and group names are: + + gpio pins: + + These all support bias-high-impediance, bias-pull-up, bias-pull-down, and + bias-bus-hold (which can also be provided to any of the groups below to set + it for all pins in that group). + + They also all support the some form of muxing. Any pins which are contained + in one of the mux groups (see below) can be muxed only to the functions + supported by the mux group. All other pins can be muxed to the "perip" + function which which enables them with their intended peripheral. + + Different pins in the same mux group cannot be muxed to different functions, + however it is possible to mux only a subset of the pins in a mux group to a + particular function and leave the remaining pins unmuxed. This is useful if + the board connects certain pins in a group to other devices to be controlled + by GPIO, and you don't want the usual peripheral to have any control of the + pin. + + ant_sel0, ant_sel1, gain0, gain1, gain2, gain3, gain4, gain5, gain6, gain7, + i2s_bclk_out, i2s_din, i2s_dout0, i2s_dout1, i2s_dout2, i2s_lrclk_out, + i2s_mclk, pa_on, pdm_a, pdm_b, pdm_c, pdm_d, pll_on, rx_hp, rx_on, + scb0_sclk, scb0_sdat, scb1_sclk, scb1_sdat, scb2_sclk, scb2_sdat, sdh_cd, + sdh_clk_in, sdh_wp, sdio_clk, sdio_cmd, sdio_d0, sdio_d1, sdio_d2, sdio_d3, + spi0_cs0, spi0_cs1, spi0_cs2, spi0_din, spi0_dout, spi0_mclk, spi1_cs0, + spi1_cs1, spi1_cs2, spi1_din, spi1_dout, spi1_mclk, tft_blank_ls, tft_blue0, + tft_blue1, tft_blue2, tft_blue3, tft_blue4, tft_blue5, tft_blue6, tft_blue7, + tft_green0, tft_green1, tft_green2, tft_green3, tft_green4, tft_green5, + tft_green6, tft_green7, tft_hsync_nr, tft_panelclk, tft_pwrsave, tft_red0, + tft_red1, tft_red2, tft_red3, tft_red4, tft_red5, tft_red6, tft_red7, + tft_vd12acb, tft_vdden_gd, tft_vsync_ns, tx_on, uart0_cts, uart0_rts, + uart0_rxd, uart0_txd, uart1_rxd, uart1_txd. + + bias-high-impediance: supported. + bias-pull-up: supported. + bias-pull-down: supported. + bias-bus-hold: supported. + function: perip or those supported by pin's mux group. + + other pins: + + These other pins are part of various pin groups below, but can't be + controlled as GPIOs. They do however support bias-high-impediance, + bias-pull-up, bias-pull-down, and bias-bus-hold (which can also be provided + to any of the groups below to set it for all pins in that group). + + clk_out0, clk_out1, tck, tdi, tdo, tms, trst. + + bias-high-impediance: supported. + bias-pull-up: supported. + bias-pull-down: supported. + bias-bus-hold: supported. + + mux groups: + + These all support function, and some support drive configs. + + afe + pins: tx_on, rx_on, pll_on, pa_on, rx_hp, ant_sel0, + ant_sel1, gain0, gain1, gain2, gain3, gain4, + gain5, gain6, gain7. + function: afe, ts_out_0. + input-schmitt-enable: supported. + input-schmitt-disable: supported. + drive-strength: supported. + pdm_d + pins: pdm_d. + function: pdm_dac, usb_vbus. + sdh + pins: sdh_cd, sdh_wp, sdh_clk_in. + function: sdh, sdio. + sdio + pins: sdio_clk, sdio_cmd, sdio_d0, sdio_d1, sdio_d2, + sdio_d3. + function: sdio, sdh. + spi1_cs2 + pins: spi1_cs2. + function: spi1_cs2, usb_vbus. + tft + pins: tft_red0, tft_red1, tft_red2, tft_red3, + tft_red4, tft_red5, tft_red6, tft_red7, + tft_green0, tft_green1, tft_green2, tft_green3, + tft_green4, tft_green5, tft_green6, tft_green7, + tft_blue0, tft_blue1, tft_blue2, tft_blue3, + tft_blue4, tft_blue5, tft_blue6, tft_blue7, + tft_vdden_gd, tft_panelclk, tft_blank_ls, + tft_vsync_ns, tft_hsync_nr, tft_vd12acb, + tft_pwrsave. + function: tft, ext_dac, not_iqadc_stb, iqdac_stb, ts_out_1, + lcd_trace, phy_ringosc. + input-schmitt-enable: supported. + input-schmitt-disable: supported. + drive-strength: supported. + + drive groups: + + These all support input-schmitt-enable, input-schmitt-disable, + and drive-strength. + + jtag + pins: tck, trst, tdi, tdo, tms. + scb1 + pins: scb1_sdat, scb1_sclk. + scb2 + pins: scb2_sdat, scb2_sclk. + spi0 + pins: spi0_mclk, spi0_cs0, spi0_cs1, spi0_cs2, spi0_dout, spi0_din. + spi1 + pins: spi1_mclk, spi1_cs0, spi1_cs1, spi1_cs2, spi1_dout, spi1_din. + uart + pins: uart0_txd, uart0_rxd, uart0_rts, uart0_cts, + uart1_txd, uart1_rxd. + drive_i2s + pins: clk_out1, i2s_din, i2s_dout0, i2s_dout1, i2s_dout2, + i2s_lrclk_out, i2s_bclk_out, i2s_mclk. + drive_pdm + pins: clk_out0, pdm_b, pdm_a. + drive_scb0 + pins: scb0_sclk, scb0_sdat, pdm_d, pdm_c. + drive_sdio + pins: sdio_clk, sdio_cmd, sdio_d0, sdio_d1, sdio_d2, sdio_d3, + sdh_wp, sdh_cd, sdh_clk_in. + + convenience groups: + + These are just convenient groupings of pins and don't support any drive + configs. + + uart0 + pins: uart0_cts, uart0_rts, uart0_rxd, uart0_txd. + uart1 + pins: uart1_rxd, uart1_txd. + scb0 + pins: scb0_sclk, scb0_sdat. + i2s + pins: i2s_bclk_out, i2s_din, i2s_dout0, i2s_dout1, i2s_dout2, + i2s_lrclk_out, i2s_mclk. + +Example: + + pinctrl: pinctrl@02005800 { + #gpio-range-cells = <3>; + compatible = "img,tz1090-pinctrl"; + reg = <0x02005800 0xe4>; + }; + +Example board file extract: + + &pinctrl { + uart0_default: uart0 { + uart0_cfg { + tz1090,pins = "uart0_rxd", + "uart0_txd"; + tz1090,function = "perip"; + }; + }; + tft_default: tft { + tft_cfg { + tz1090,pins = "tft"; + tz1090,function = "tft"; + }; + }; + }; + + uart@02004b00 { + pinctrl-names = "default"; + pinctrl-0 = <&uart0_default>; + }; diff --git a/Documentation/devicetree/bindings/pinctrl/marvell,dove-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/marvell,dove-pinctrl.txt index a648aaa..50ec351 100644 --- a/Documentation/devicetree/bindings/pinctrl/marvell,dove-pinctrl.txt +++ b/Documentation/devicetree/bindings/pinctrl/marvell,dove-pinctrl.txt @@ -10,29 +10,31 @@ Required properties: Available mpp pins/groups and functions: Note: brackets (x) are not part of the mpp name for marvell,function and given only for more detailed description in this document. +Note: pmu* also allows for Power Management functions listed below name pins functions ================================================================================ -mpp0 0 gpio, pmu, uart2(rts), sdio0(cd), lcd0(pwm) -mpp1 1 gpio, pmu, uart2(cts), sdio0(wp), lcd1(pwm) +mpp0 0 gpio, pmu, uart2(rts), sdio0(cd), lcd0(pwm), pmu* +mpp1 1 gpio, pmu, uart2(cts), sdio0(wp), lcd1(pwm), pmu* mpp2 2 gpio, pmu, uart2(txd), sdio0(buspwr), sata(prsnt), - uart1(rts) + uart1(rts), pmu* mpp3 3 gpio, pmu, uart2(rxd), sdio0(ledctrl), sata(act), - uart1(cts), lcd-spi(cs1) -mpp4 4 gpio, pmu, uart3(rts), sdio1(cd), spi1(miso) -mpp5 5 gpio, pmu, uart3(cts), sdio1(wp), spi1(cs) -mpp6 6 gpio, pmu, uart3(txd), sdio1(buspwr), spi1(mosi) -mpp7 7 gpio, pmu, uart3(rxd), sdio1(ledctrl), spi1(sck) -mpp8 8 gpio, pmu, watchdog(rstout) -mpp9 9 gpio, pmu, pex1(clkreq) -mpp10 10 gpio, pmu, ssp(sclk) + uart1(cts), lcd-spi(cs1), pmu* +mpp4 4 gpio, pmu, uart3(rts), sdio1(cd), spi1(miso), pmu* +mpp5 5 gpio, pmu, uart3(cts), sdio1(wp), spi1(cs), pmu* +mpp6 6 gpio, pmu, uart3(txd), sdio1(buspwr), spi1(mosi), pmu* +mpp7 7 gpio, pmu, uart3(rxd), sdio1(ledctrl), spi1(sck), pmu* +mpp8 8 gpio, pmu, watchdog(rstout), pmu* +mpp9 9 gpio, pmu, pex1(clkreq), pmu* +mpp10 10 gpio, pmu, ssp(sclk), pmu* mpp11 11 gpio, pmu, sata(prsnt), sata-1(act), sdio0(ledctrl), - sdio1(ledctrl), pex0(clkreq) -mpp12 12 gpio, pmu, uart2(rts), audio0(extclk), sdio1(cd), sata(act) + sdio1(ledctrl), pex0(clkreq), pmu* +mpp12 12 gpio, pmu, uart2(rts), audio0(extclk), sdio1(cd), + sata(act), pmu* mpp13 13 gpio, pmu, uart2(cts), audio1(extclk), sdio1(wp), - ssp(extclk) -mpp14 14 gpio, pmu, uart2(txd), sdio1(buspwr), ssp(rxd) -mpp15 15 gpio, pmu, uart2(rxd), sdio1(ledctrl), ssp(sfrm) + ssp(extclk), pmu* +mpp14 14 gpio, pmu, uart2(txd), sdio1(buspwr), ssp(rxd), pmu* +mpp15 15 gpio, pmu, uart2(rxd), sdio1(ledctrl), ssp(sfrm), pmu* mpp16 16 gpio, uart3(rts), sdio0(cd), ac97(sdi1), lcd-spi(cs1) mpp17 17 gpio, uart3(cts), sdio0(wp), ac97(sdi2), twsi(sda), ac97-1(sysclko) @@ -57,6 +59,21 @@ mpp_nand 64-71 gpo, nand audio0 - i2s, ac97 twsi - none, opt1, opt2, opt3 +Power Management functions (pmu*): +pmu-nc Pin not driven by any PM function +pmu-low Pin driven low (0) +pmu-high Pin driven high (1) +pmic(sdi) Pin is used for PMIC SDI +cpu-pwr-down Pin is used for CPU_PWRDWN +standby-pwr-down Pin is used for STBY_PWRDWN +core-pwr-good Pin is used for CORE_PWR_GOOD (Pins 0-7 only) +cpu-pwr-good Pin is used for CPU_PWR_GOOD (Pins 8-15 only) +bat-fault Pin is used for BATTERY_FAULT +ext0-wakeup Pin is used for EXT0_WU +ext1-wakeup Pin is used for EXT0_WU +ext2-wakeup Pin is used for EXT0_WU +pmu-blink Pin is used for blink function + Notes: * group "mpp_audio1" allows the following functions and gpio pins: - gpio : gpio on pins 52-57 diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt index c95ea82..aeb3c99 100644 --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt @@ -126,3 +126,51 @@ device; they may be grandchildren, for example. Whether this is legal, and whether there is any interaction between the child and intermediate parent nodes, is again defined entirely by the binding for the individual pin controller device. + +== Using generic pinconfig options == + +Generic pinconfig parameters can be used by defining a separate node containing +the applicable parameters (and optional values), like: + +pcfg_pull_up: pcfg_pull_up { + bias-pull-up; + drive-strength = <20>; +}; + +This node should then be referenced in the appropriate pinctrl node as a phandle +and parsed in the driver using the pinconf_generic_parse_dt_config function. + +Supported configuration parameters are: + +bias-disable - disable any pin bias +bias-high-impedance - high impedance mode ("third-state", "floating") +bias-bus-hold - latch weakly +bias-pull-up - pull up the pin +bias-pull-down - pull down the pin +bias-pull-pin-default - use pin-default pull state +drive-push-pull - drive actively high and low +drive-open-drain - drive with open drain +drive-open-source - drive with open source +drive-strength - sink or source at most X mA +input-schmitt-enable - enable schmitt-trigger mode +input-schmitt-disable - disable schmitt-trigger mode +input-debounce - debounce mode with debound time X +low-power-enable - enable low power mode +low-power-disable - disable low power mode +output-low - set the pin to output mode with low level +output-high - set the pin to output mode with high level + +Arguments for parameters: + +- bias-pull-up, -down and -pin-default take as optional argument on hardware + supporting it the pull strength in Ohm. bias-disable will disable the pull. + +- drive-strength takes as argument the target strength in mA. + +- input-debounce takes the debounce time in usec as argument + or 0 to disable debouncing + +All parameters not listed here, do not take an argument. + +More in-depth documentation on these parameters can be found in +<include/linux/pinctrl/pinconfig-generic.h> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt index 08f0c3d..5a02e30 100644 --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt @@ -18,7 +18,8 @@ Optional properties: pin functions is ignored - pinctrl-single,bit-per-mux : boolean to indicate that one register controls - more than one pin + more than one pin, for which "pinctrl-single,function-mask" property specifies + position mask of pin. - pinctrl-single,drive-strength : array of value that are used to configure drive strength in the pinmux register. They're value of drive strength diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,pfc-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,pfc-pinctrl.txt new file mode 100644 index 0000000..d5dac7b --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/renesas,pfc-pinctrl.txt @@ -0,0 +1,153 @@ +* Renesas Pin Function Controller (GPIO and Pin Mux/Config) + +The Pin Function Controller (PFC) is a Pin Mux/Config controller. On SH7372, +SH73A0, R8A73A4 and R8A7740 it also acts as a GPIO controller. + + +Pin Control +----------- + +Required Properties: + + - compatible: should be one of the following. + - "renesas,pfc-r8a73a4": for R8A73A4 (R-Mobile APE6) compatible pin-controller. + - "renesas,pfc-r8a7740": for R8A7740 (R-Mobile A1) compatible pin-controller. + - "renesas,pfc-r8a7778": for R8A7778 (R-Mobile M1) compatible pin-controller. + - "renesas,pfc-r8a7779": for R8A7779 (R-Car H1) compatible pin-controller. + - "renesas,pfc-r8a7790": for R8A7790 (R-Car H2) compatible pin-controller. + - "renesas,pfc-sh7372": for SH7372 (SH-Mobile AP4) compatible pin-controller. + - "renesas,pfc-sh73a0": for SH73A0 (SH-Mobile AG5) compatible pin-controller. + + - reg: Base address and length of each memory resource used by the pin + controller hardware module. + +Optional properties: + + - #gpio-range-cells: Mandatory when the PFC doesn't handle GPIO, forbidden + otherwise. Should be 3. + +The PFC node also acts as a container for pin configuration nodes. Please refer +to pinctrl-bindings.txt in this directory for the definition of the term "pin +configuration node" and for the common pinctrl bindings used by client devices. + +Each pin configuration node represents a desired configuration for a pin, a +pin group, or a list of pins or pin groups. The configuration can include the +function to select on those pin(s) and pin configuration parameters (such as +pull-up and pull-down). + +Pin configuration nodes contain pin configuration properties, either directly +or grouped in child subnodes. Both pin muxing and configuration parameters can +be grouped in that way and referenced as a single pin configuration node by +client devices. + +A configuration node or subnode must reference at least one pin (through the +pins or pin groups properties) and contain at least a function or one +configuration parameter. When the function is present only pin groups can be +used to reference pins. + +All pin configuration nodes and subnodes names are ignored. All of those nodes +are parsed through phandles and processed purely based on their content. + +Pin Configuration Node Properties: + +- renesas,pins : An array of strings, each string containing the name of a pin. +- renesas,groups : An array of strings, each string containing the name of a pin + group. + +- renesas,function: A string containing the name of the function to mux to the + pin group(s) specified by the renesas,groups property + + Valid values for pin, group and function names can be found in the group and + function arrays of the PFC data file corresponding to the SoC + (drivers/pinctrl/sh-pfc/pfc-*.c) + +The pin configuration parameters use the generic pinconf bindings defined in +pinctrl-bindings.txt in this directory. The supported parameters are +bias-disable, bias-pull-up and bias-pull-down. + + +GPIO +---- + +On SH7372, SH73A0, R8A73A4 and R8A7740 the PFC node is also a GPIO controller +node. + +Required Properties: + + - gpio-controller: Marks the device node as a gpio controller. + + - #gpio-cells: Should be 2. The first cell is the GPIO number and the second + cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the + GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. + +The syntax of the gpio specifier used by client nodes should be the following +with values derived from the SoC user manual. + + <[phandle of the gpio controller node] + [pin number within the gpio controller] + [flags]> + +On other mach-shmobile platforms GPIO is handled by the gpio-rcar driver. +Please refer to Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt +for documentation of the GPIO device tree bindings on those platforms. + + +Examples +-------- + +Example 1: SH73A0 (SH-Mobile AG5) pin controller node + + pfc: pfc@e6050000 { + compatible = "renesas,pfc-sh73a0"; + reg = <0xe6050000 0x8000>, + <0xe605801c 0x1c>; + gpio-controller; + #gpio-cells = <2>; + }; + +Example 2: A GPIO LED node that references a GPIO + + #include <dt-bindings/gpio/gpio.h> + + leds { + compatible = "gpio-leds"; + led1 { + gpios = <&pfc 20 GPIO_ACTIVE_LOW>; + }; + }; + +Example 3: KZM-A9-GT (SH-Mobile AG5) default pin state hog and pin control maps + for the MMCIF and SCIFA4 devices + + &pfc { + pinctrl-0 = <&scifa4_pins>; + pinctrl-names = "default"; + + mmcif_pins: mmcif { + mux { + renesas,groups = "mmc0_data8_0", "mmc0_ctrl_0"; + renesas,function = "mmc0"; + }; + cfg { + renesas,groups = "mmc0_data8_0"; + renesas,pins = "PORT279"; + bias-pull-up; + }; + }; + + scifa4_pins: scifa4 { + renesas,groups = "scifa4_data", "scifa4_ctrl"; + renesas,function = "scifa4"; + }; + }; + +Example 4: KZM-A9-GT (SH-Mobile AG5) default pin state for the MMCIF device + + &mmcif { + pinctrl-0 = <&mmcif_pins>; + pinctrl-names = "default"; + + bus-width = <8>; + vmmc-supply = <®_1p8v>; + status = "okay"; + }; diff --git a/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt new file mode 100644 index 0000000..b0fb101 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt @@ -0,0 +1,97 @@ +* Rockchip Pinmux Controller + +The Rockchip Pinmux Controller, enables the IC +to share one PAD to several functional blocks. The sharing is done by +multiplexing the PAD input/output signals. For each PAD there are up to +4 muxing options with option 0 being the use as a GPIO. + +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 Rockchip pin configuration node is a node of a group of pins which can be +used for a specific device or function. This node represents both mux and +config of the pins in that group. The 'pins' selects the function mode(also +named pin mode) this pin can work on and the 'config' configures various pad +settings such as pull-up, etc. + +The pins are grouped into up to 5 individual pin banks which need to be +defined as gpio sub-nodes of the pinmux controller. + +Required properties for iomux controller: + - compatible: one of "rockchip,rk2928-pinctrl", "rockchip,rk3066a-pinctrl" + "rockchip,rk3066b-pinctrl", "rockchip,rk3188-pinctrl" + +Required properties for gpio sub nodes: + - compatible: "rockchip,gpio-bank" + - reg: register of the gpio bank (different than the iomux registerset) + - interrupts: base interrupt of the gpio bank in the interrupt controller + - clocks: clock that drives this bank + - gpio-controller: identifies the node as a gpio controller and pin bank. + - #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO + binding is used, the amount of cells must be specified as 2. See generic + GPIO binding documentation for description of particular cells. + - interrupt-controller: identifies the controller node as interrupt-parent. + - #interrupt-cells: the value of this property should be 2 and the interrupt + cells should use the standard two-cell scheme described in + bindings/interrupt-controller/interrupts.txt + +Required properties for pin configuration node: + - rockchip,pins: 3 integers array, represents a group of pins mux and config + setting. The format is rockchip,pins = <PIN_BANK PIN_BANK_IDX MUX &phandle>. + The MUX 0 means gpio and MUX 1 to 3 mean the specific device function. + The phandle of a node containing the generic pinconfig options + to use, as described in pinctrl-bindings.txt in this directory. + +Examples: + +#include <dt-bindings/pinctrl/rockchip.h> + +... + +pinctrl@20008000 { + compatible = "rockchip,rk3066a-pinctrl"; + reg = <0x20008000 0x150>; + #address-cells = <1>; + #size-cells = <1>; + ranges; + + gpio0: gpio0@20034000 { + compatible = "rockchip,gpio-bank"; + reg = <0x20034000 0x100>; + interrupts = <GIC_SPI 54 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&clk_gates8 9>; + + gpio-controller; + #gpio-cells = <2>; + + interrupt-controller; + #interrupt-cells = <2>; + }; + + ... + + pcfg_pull_default: pcfg_pull_default { + bias-pull-pin-default + }; + + uart2 { + uart2_xfer: uart2-xfer { + rockchip,pins = <RK_GPIO1 8 1 &pcfg_pull_default>, + <RK_GPIO1 9 1 &pcfg_pull_default>; + }; + }; +}; + +uart2: serial@20064000 { + compatible = "snps,dw-apb-uart"; + reg = <0x20064000 0x400>; + interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>; + reg-shift = <2>; + reg-io-width = <1>; + clocks = <&mux_uart2>; + status = "okay"; + + pinctrl-names = "default"; + pinctrl-0 = <&uart2_xfer>; +}; diff --git a/Documentation/devicetree/bindings/pinctrl/ste,abx500.txt b/Documentation/devicetree/bindings/pinctrl/ste,abx500.txt new file mode 100644 index 0000000..e3865e1 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/ste,abx500.txt @@ -0,0 +1,352 @@ +ST Ericsson abx500 pinmux controller + +Required properties: +- compatible: "stericsson,ab8500-gpio", "stericsson,ab8540-gpio", + "stericsson,ab8505-gpio", "stericsson,ab9540-gpio", + +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". + +ST Ericsson's 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 input, output, pull up, pull down... + +The name of each subnode is not important; all subnodes should be enumerated +and processed purely based on their content. + +Required subnode-properties: +- ste,pins : An array of strings. Each string contains the name of a pin or + group. + +Optional subnode-properties: +- ste,function: A string containing the name of the function to mux to the + pin or group. + +- generic pin configuration option to use. Example : + + default_cfg { + ste,pins = "GPIO1"; + bias-disable; + }; + +- ste,config: Handle of pin configuration node containing the generic + pinconfig options to use, as described in pinctrl-bindings.txt in + this directory. Example : + + pcfg_bias_disable: pcfg_bias_disable { + bias-disable; + }; + + default_cfg { + ste,pins = "GPIO1"; + ste.config = <&pcfg_bias_disable>; + }; + +Example board file extract: + +&pinctrl_abx500 { + pinctrl-names = "default"; + pinctrl-0 = <&sysclkreq2_default_mode>, <&sysclkreq3_default_mode>, <&gpio3_default_mode>, <&sysclkreq6_default_mode>, <&pwmout1_default_mode>, <&pwmout2_default_mode>, <&pwmout3_default_mode>, <&adi1_default_mode>, <&dmic12_default_mode>, <&dmic34_default_mode>, <&dmic56_default_mode>, <&sysclkreq5_default_mode>, <&batremn_default_mode>, <&service_default_mode>, <&pwrctrl0_default_mode>, <&pwrctrl1_default_mode>, <&pwmextvibra1_default_mode>, <&pwmextvibra2_default_mode>, <&gpio51_default_mode>, <&gpio52_default_mode>, <&gpio53_default_mode>, <&gpio54_default_mode>, <&pdmclkdat_default_mode>; + + sysclkreq2 { + sysclkreq2_default_mode: sysclkreq2_default { + default_mux { + ste,function = "sysclkreq"; + ste,pins = "sysclkreq2_d_1"; + }; + default_cfg { + ste,pins = "GPIO1"; + bias-disable; + }; + }; + }; + sysclkreq3 { + sysclkreq3_default_mode: sysclkreq3_default { + default_mux { + ste,function = "sysclkreq"; + ste,pins = "sysclkreq3_d_1"; + }; + default_cfg { + ste,pins = "GPIO2"; + output-low; + }; + }; + }; + gpio3 { + gpio3_default_mode: gpio3_default { + default_mux { + ste,function = "gpio"; + ste,pins = "gpio3_a_1"; + }; + default_cfg { + ste,pins = "GPIO3"; + output-low; + }; + }; + }; + sysclkreq6 { + sysclkreq6_default_mode: sysclkreq6_default { + default_mux { + ste,function = "sysclkreq"; + ste,pins = "sysclkreq6_d_1"; + }; + default_cfg { + ste,pins = "GPIO4"; + bias-disable; + }; + }; + }; + pwmout1 { + pwmout1_default_mode: pwmout1_default { + default_mux { + ste,function = "pwmout"; + ste,pins = "pwmout1_d_1"; + }; + default_cfg { + ste,pins = "GPIO14"; + output-low; + }; + }; + }; + pwmout2 { + pwmout2_default_mode: pwmout2_default { + pwmout2_default_mux { + ste,function = "pwmout"; + ste,pins = "pwmout2_d_1"; + }; + pwmout2_default_cfg { + ste,pins = "GPIO15"; + output-low; + }; + }; + }; + pwmout3 { + pwmout3_default_mode: pwmout3_default { + pwmout3_default_mux { + ste,function = "pwmout"; + ste,pins = "pwmout3_d_1"; + }; + pwmout3_default_cfg { + ste,pins = "GPIO16"; + output-low; + }; + }; + }; + adi1 { + + adi1_default_mode: adi1_default { + adi1_default_mux { + ste,function = "adi1"; + ste,pins = "adi1_d_1"; + }; + adi1_default_cfg1 { + ste,pins = "GPIO17","GPIO19","GPIO20"; + bias-disable; + }; + adi1_default_cfg2 { + ste,pins = "GPIO18"; + output-low; + }; + }; + }; + dmic12 { + dmic12_default_mode: dmic12_default { + dmic12_default_mux { + ste,function = "dmic"; + ste,pins = "dmic12_d_1"; + }; + dmic12_default_cfg1 { + ste,pins = "GPIO27"; + output-low; + }; + dmic12_default_cfg2 { + ste,pins = "GPIO28"; + bias-disable; + }; + }; + }; + dmic34 { + dmic34_default_mode: dmic34_default { + dmic34_default_mux { + ste,function = "dmic"; + ste,pins = "dmic34_d_1"; + }; + dmic34_default_cfg1 { + ste,pins = "GPIO29"; + output-low; + }; + dmic34_default_cfg2 { + ste,pins = "GPIO30"; + bias-disable;{ + + }; + }; + }; + dmic56 { + dmic56_default_mode: dmic56_default { + dmic56_default_mux { + ste,function = "dmic"; + ste,pins = "dmic56_d_1"; + }; + dmic56_default_cfg1 { + ste,pins = "GPIO31"; + output-low; + }; + dmic56_default_cfg2 { + ste,pins = "GPIO32"; + bias-disable; + }; + }; + }; + sysclkreq5 { + sysclkreq5_default_mode: sysclkreq5_default { + sysclkreq5_default_mux { + ste,function = "sysclkreq"; + ste,pins = "sysclkreq5_d_1"; + }; + sysclkreq5_default_cfg { + ste,pins = "GPIO42"; + output-low; + }; + }; + }; + batremn { + batremn_default_mode: batremn_default { + batremn_default_mux { + ste,function = "batremn"; + ste,pins = "batremn_d_1"; + }; + batremn_default_cfg { + ste,pins = "GPIO43"; + bias-disable; + }; + }; + }; + service { + service_default_mode: service_default { + service_default_mux { + ste,function = "service"; + ste,pins = "service_d_1"; + }; + service_default_cfg { + ste,pins = "GPIO44"; + bias-disable; + }; + }; + }; + pwrctrl0 { + pwrctrl0_default_mux: pwrctrl0_mux { + pwrctrl0_default_mux { + ste,function = "pwrctrl"; + ste,pins = "pwrctrl0_d_1"; + }; + }; + pwrctrl0_default_mode: pwrctrl0_default { + pwrctrl0_default_cfg { + ste,pins = "GPIO45"; + bias-disable; + }; + }; + }; + pwrctrl1 { + pwrctrl1_default_mux: pwrctrl1_mux { + pwrctrl1_default_mux { + ste,function = "pwrctrl"; + ste,pins = "pwrctrl1_d_1"; + }; + }; + pwrctrl1_default_mode: pwrctrl1_default { + pwrctrl1_default_cfg { + ste,pins = "GPIO46"; + bias-disable; + }; + }; + }; + pwmextvibra1 { + pwmextvibra1_default_mode: pwmextvibra1_default { + pwmextvibra1_default_mux { + ste,function = "pwmextvibra"; + ste,pins = "pwmextvibra1_d_1"; + }; + pwmextvibra1_default_cfg { + ste,pins = "GPIO47"; + bias-disable; + }; + }; + }; + pwmextvibra2 { + pwmextvibra2_default_mode: pwmextvibra2_default { + pwmextvibra2_default_mux { + ste,function = "pwmextvibra"; + ste,pins = "pwmextvibra2_d_1"; + }; + pwmextvibra1_default_cfg { + ste,pins = "GPIO48"; + bias-disable; + }; + }; + }; + gpio51 { + gpio51_default_mode: gpio51_default { + gpio51_default_mux { + ste,function = "gpio"; + ste,pins = "gpio51_a_1"; + }; + gpio51_default_cfg { + ste,pins = "GPIO51"; + output-low; + }; + }; + }; + gpio52 { + gpio52_default_mode: gpio52_default { + gpio52_default_mux { + ste,function = "gpio"; + ste,pins = "gpio52_a_1"; + }; + gpio52_default_cfg { + ste,pins = "GPIO52"; + bias-pull-down; + }; + }; + }; + gpio53 { + gpio53_default_mode: gpio53_default { + gpio53_default_mux { + ste,function = "gpio"; + ste,pins = "gpio53_a_1"; + }; + gpio53_default_cfg { + ste,pins = "GPIO53"; + bias-pull-down; + }; + }; + }; + gpio54 { + gpio54_default_mode: gpio54_default { + gpio54_default_mux { + ste,function = "gpio"; + ste,pins = "gpio54_a_1"; + }; + gpio54_default_cfg { + ste,pins = "GPIO54"; + output-low; + }; + }; + }; + pdmclkdat { + pdmclkdat_default_mode: pdmclkdat_default { + pdmclkdat_default_mux { + ste,function = "pdm"; + ste,pins = "pdmclkdat_d_1"; + }; + pdmclkdat_default_cfg { + ste,pins = "GPIO55", "GPIO56"; + bias-disable; + }; + }; + }; +}; diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt index 447fd4c..c5948c7 100644 --- a/Documentation/pinctrl.txt +++ b/Documentation/pinctrl.txt @@ -203,15 +203,8 @@ using a certain resistor value - pull up and pull down - so that the pin has a stable value when nothing is driving the rail it is connected to, or when it's unconnected. -Pin configuration can be programmed either using the explicit APIs described -immediately below, or by adding configuration entries into the mapping table; -see section "Board/machine configuration" below. - -For example, a platform may do the following to pull up a pin to VDD: - -#include <linux/pinctrl/consumer.h> - -ret = pin_config_set("foo-dev", "FOO_GPIO_PIN", PLATFORM_X_PULL_UP); +Pin configuration can be programmed by adding configuration entries into the +mapping table; see section "Board/machine configuration" below. The format and meaning of the configuration parameter, PLATFORM_X_PULL_UP above, is entirely defined by the pin controller driver. @@ -350,6 +343,23 @@ chip b: - GPIO range : [48 .. 55] - pin range : [64 .. 71] +The above examples assume the mapping between the GPIOs and pins is +linear. If the mapping is sparse or haphazard, an array of arbitrary pin +numbers can be encoded in the range like this: + +static const unsigned range_pins[] = { 14, 1, 22, 17, 10, 8, 6, 2 }; + +static struct pinctrl_gpio_range gpio_range = { + .name = "chip", + .id = 0, + .base = 32, + .pins = &range_pins, + .npins = ARRAY_SIZE(range_pins), + .gc = &chip; +}; + +In this case the pin_base property will be ignored. + When GPIO-specific functions in the pin control subsystem are called, these ranges will be used to look up the appropriate pin controller by inspecting and matching the pin to the pin ranges across all controllers. When a @@ -357,9 +367,9 @@ pin controller handling the matching range is found, GPIO-specific functions will be called on that specific pin controller. For all functionalities dealing with pin biasing, pin muxing etc, the pin -controller subsystem will subtract the range's .base offset from the passed -in gpio number, and add the ranges's .pin_base offset to retrive a pin number. -After that, the subsystem passes it on to the pin control driver, so the driver +controller subsystem will look up the corresponding pin number from the passed +in gpio number, and use the range's internals to retrive a pin number. After +that, the subsystem passes it on to the pin control driver, so the driver will get an pin number into its handled number range. Further it is also passed the range ID value, so that the pin controller knows which range it should deal with. @@ -368,6 +378,7 @@ Calling pinctrl_add_gpio_range from pinctrl driver is DEPRECATED. Please see section 2.1 of Documentation/devicetree/bindings/gpio/gpio.txt on how to bind pinctrl and gpio drivers. + PINMUX interfaces ================= @@ -1226,8 +1237,8 @@ setting up the config and muxing for the pins right before the device is probing, nevertheless orthogonal to the GPIO subsystem. But there are also situations where it makes sense for the GPIO subsystem -to communicate directly with with the pinctrl subsystem, using the latter -as a back-end. This is when the GPIO driver may call out to the functions +to communicate directly with the pinctrl subsystem, using the latter as a +back-end. This is when the GPIO driver may call out to the functions described in the section "Pin control interaction with the GPIO subsystem" above. This only involves per-pin multiplexing, and will be completely hidden behind the gpio_*() function namespace. In this case, the driver |