diff options
Diffstat (limited to 'Documentation/devicetree/bindings/gpio')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-stmpe.txt | 18 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/gpio/spear_spics.txt | 50 |
2 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-stmpe.txt b/Documentation/devicetree/bindings/gpio/gpio-stmpe.txt new file mode 100644 index 0000000..a0e4cf8 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-stmpe.txt @@ -0,0 +1,18 @@ +STMPE gpio +---------- + +Required properties: + - compatible: "st,stmpe-gpio" + +Optional properties: + - st,norequest-mask: bitmask specifying which GPIOs should _not_ be requestable + due to different usage (e.g. touch, keypad) + +Node name must be stmpe_gpio and should be child node of stmpe node to which it +belongs. + +Example: + stmpe_gpio { + compatible = "st,stmpe-gpio"; + st,norequest-mask = <0x20>; //gpio 5 can't be used + }; diff --git a/Documentation/devicetree/bindings/gpio/spear_spics.txt b/Documentation/devicetree/bindings/gpio/spear_spics.txt new file mode 100644 index 0000000..96c37eb --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/spear_spics.txt @@ -0,0 +1,50 @@ +=== ST Microelectronics SPEAr SPI CS Driver === + +SPEAr platform provides a provision to control chipselects of ARM PL022 Prime +Cell spi controller through its system registers, which otherwise remains under +PL022 control. If chipselect remain under PL022 control then they would be +released as soon as transfer is over and TxFIFO becomes empty. This is not +desired by some of the device protocols above spi which expect (multiple) +transfers without releasing their chipselects. + +Chipselects can be controlled by software by turning them as GPIOs. SPEAr +provides another interface through system registers through which software can +directly control each PL022 chipselect. Hence, it is natural for SPEAr to export +the control of this interface as gpio. + +Required properties: + + * compatible: should be defined as "st,spear-spics-gpio" + * reg: mentioning address range of spics controller + * st-spics,peripcfg-reg: peripheral configuration register offset + * st-spics,sw-enable-bit: bit offset to enable sw control + * st-spics,cs-value-bit: bit offset to drive chipselect low or high + * st-spics,cs-enable-mask: chip select number bit mask + * st-spics,cs-enable-shift: chip select number program offset + * gpio-controller: Marks the device node as gpio controller + * #gpio-cells: should be 1 and will mention chip select number + +All the above bit offsets are within peripcfg register. + +Example: +------- +spics: spics@e0700000{ + compatible = "st,spear-spics-gpio"; + reg = <0xe0700000 0x1000>; + st-spics,peripcfg-reg = <0x3b0>; + st-spics,sw-enable-bit = <12>; + st-spics,cs-value-bit = <11>; + st-spics,cs-enable-mask = <3>; + st-spics,cs-enable-shift = <8>; + gpio-controller; + #gpio-cells = <2>; +}; + + +spi0: spi@e0100000 { + status = "okay"; + num-cs = <3>; + cs-gpios = <&gpio1 7 0>, <&spics 0>, + <&spics 1>; + ... +} |