Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> --- .../devicetree/bindings/misc/mux-controller.txt | 127 +++++++++++++++++++++ .../devicetree/bindings/misc/mux-gpio.txt | 68 +++++++++++ MAINTAINERS | 5 + 3 files changed, 200 insertions(+) create mode 100644 Documentation/devicetree/bindings/misc/mux-controller.txt create mode 100644 Documentation/devicetree/bindings/misc/mux-gpio.txt diff --git a/Documentation/devicetree/bindings/misc/mux-controller.txt b/Documentation/devicetree/bindings/misc/mux-controller.txt new file mode 100644 index 000000000000..19c36b73173e --- /dev/null +++ b/Documentation/devicetree/bindings/misc/mux-controller.txt @@ -0,0 +1,127 @@ +Common multiplexer controller bindings +====================================== + +A multiplexer (or mux) controller will have one, or several, consumer devices +that uses the mux controller. Thus, a mux controller can possibly control +several parallel multiplexers, presumably there will be at least one +multiplexer needed by each consumer.. + +A mux controller provides a number of states to its consumers, and the state +space is a simple zero-based enumeration. I.e. 0-1 for a 2-way multiplexer, +0-7 for an 8-way multiplexer, etc. + + +Consumers +--------- + +Mux controller consumers should specify a list of mux controllers that they +want to use with a property containing a 'mux-ctrl-list': + + mux-ctrl-list ::= <single-mux-ctrl> [mux-ctrl-list] + single-mux-ctrl ::= <mux-ctrl-phandle> [mux-ctrl-specifier] + mux-ctrl-phandle : phandle to mux controller node + mux-ctrl-specifier : array of #mux-control-cells specifying the + given mux controller (controller specific) + +Mux controller properties should be named "mux-controls". The exact meaning of +each mux controller property must be documented in the device tree binding for +each consumer. An optional property "mux-control-names" may contain a list of +strings to label each of the mux controllers listed in the "mux-controls" +property. + +Drivers for devices that use more than a single mux controller can use the +"mux-control-names" property to map the name of the mux controller requested by +the mux_control_get() call to an index into the list given by the +"mux-controls" property. + +mux-ctrl-specifier typically encodes the chip-relative mux controller number. +If the mux controller chip only provides a single mux controller, the +mux-ctrl-specifier can typically be left out. + +Example: + + /* One consumer of a 2-way mux controller (one GPIO-line) */ + mux: mux-controller { + compatible = "mux-gpio"; + #mux-control-cells = <0>; + + mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>; + }; + + adc-mux { + compatible = "iio-mux"; + io-channels = <&adc 0>; + io-channel-names = "parent"; + mux-controls = <&mux>; + mux-control-names = "adc"; + + channels = "sync", "in"; + }; + +Note that in the example above, specifying the "mux-control-names" is redundant +because there is only one mux controller in the list. + + /* + * Two consumers (one for an ADC line and one for an i2c bus) of + * parallel 4-way multiplexers controlled by the same two GPIO-lines. + */ + mux: mux-controller { + compatible = "mux-gpio"; + #mux-control-cells = <0>; + + mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>, + <&pioA 1 GPIO_ACTIVE_HIGH>; + }; + + adc-mux { + compatible = "iio-mux"; + io-channels = <&adc 0>; + io-channel-names = "parent"; + mux-controls = <&mux>; + + channels = "sync-1", "in", "out", "sync-2"; + }; + + i2c-mux { + compatible = "i2c-mux-simple,mux-locked"; + i2c-parent = <&i2c1>; + mux-controls = <&mux>; + + #address-cells = <1>; + #size-cells = <0>; + + i2c@0 { + reg = <0>; + #address-cells = <1>; + #size-cells = <0>; + + ssd1307: oled@3c { + /* ... */ + }; + }; + + i2c@3 { + reg = <3>; + #address-cells = <1>; + #size-cells = <0>; + + pca9555: pca9555@20 { + /* ... */ + }; + }; + }; + + +Mux controller nodes +-------------------- + +Mux controller nodes must specify the number of cells used for the +specifier using the '#mux-control-cells' property. + +An example mux controller might look like this: + + mux: adg792a@50 { + compatible = "adi,adg792a"; + reg = <0x50>; + #mux-control-cells = <1>; + }; diff --git a/Documentation/devicetree/bindings/misc/mux-gpio.txt b/Documentation/devicetree/bindings/misc/mux-gpio.txt new file mode 100644 index 000000000000..2ff814f082c8 --- /dev/null +++ b/Documentation/devicetree/bindings/misc/mux-gpio.txt @@ -0,0 +1,68 @@ +GPIO-based multiplexer controller bindings + +Define what GPIO pins are used to control a multiplexer. Or several +multiplexers, if the same pins control more than one multiplexer. + +Required properties: +- compatible : "mux-gpio" +- mux-gpios : list of gpios used to control the multiplexer, least + significant bit first. +- #mux-control-cells : <0> +* Standard mux-controller bindings as decribed in mux-controller.txt + +Optional properties: +- idle-state : if present, the state the mux will have when idle. + +The multiplexer state is defined as the number represented by the +multiplexer GPIO pins, where the first pin is the least significant +bit. An active pin is a binary 1, an inactive pin is a binary 0. + +Example: + + mux: mux-controller { + compatible = "mux-gpio"; + #mux-control-cells = <0>; + + mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>, + <&pioA 1 GPIO_ACTIVE_HIGH>; + }; + + adc-mux { + compatible = "iio-mux"; + io-channels = <&adc 0>; + io-channel-names = "parent"; + + mux-controls = <&mux>; + + channels = "sync-1", "in", "out", "sync-2"; + }; + + i2c-mux { + compatible = "i2c-mux-simple,mux-locked"; + i2c-parent = <&i2c1>; + + mux-controls = <&mux>; + + #address-cells = <1>; + #size-cells = <0>; + + i2c@0 { + reg = <0>; + #address-cells = <1>; + #size-cells = <0>; + + ssd1307: oled@3c { + /* ... */ + }; + }; + + i2c@3 { + reg = <3>; + #address-cells = <1>; + #size-cells = <0>; + + pca9555: pca9555@20 { + /* ... */ + }; + }; + }; diff --git a/MAINTAINERS b/MAINTAINERS index d8eb3843dbd4..3d4d0efc2b64 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8403,6 +8403,11 @@ S: Orphan F: drivers/mmc/host/mmc_spi.c F: include/linux/spi/mmc_spi.h +MULTIPLEXER SUBSYSTEM +M: Peter Rosin <peda@xxxxxxxxxx> +S: Maintained +F: Documentation/devicetree/bindings/misc/mux-* + MULTISOUND SOUND DRIVER M: Andrew Veliath <andrewtv@xxxxxxx> S: Maintained -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html