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authorLars Poeschel <poeschel@lemonage.de>2013-04-04 12:02:02 +0200
committerLinus Walleij <linus.walleij@linaro.org>2013-04-10 23:41:17 +0200
commit97ddb1c88b4ebe057b63346660abfee165ddd468 (patch)
treeeff1fc4d226bc72ecc8ca3887552b5477ac9298f /Documentation/devicetree/bindings/gpio
parenta2797beadfcb5a0974a30929b613b4d1adb023d1 (diff)
gpio: mcp23s08: convert driver to DT
This converts the mcp23s08 driver to be able to be used with device tree. There is a "spi-present-mask" device tree property, that allows to use multiple of this spi chips on the same chipselect. v4: - removed the ability to specify the pullup from device tree - updated binding doc v3: - removed mcp,chips device tree property in favour of a mcp,spi-present-mask and a flag for the pullup of every gpio - seperated the match table. Now there is one for i2c and one for spi - do the of reading stuff on stack of the probe function - no devm any more v2: - squashed booth patches together - fixed build warning, when CONFIG_OF is not defined - use of_match_ptr macro for of_match_table Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings/gpio')
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt47
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
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+++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
@@ -0,0 +1,47 @@
+Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for
+8-/16-bit I/O expander with serial interface (I2C/SPI)
+
+Required properties:
+- compatible : Should be
+ - "mcp,mcp23s08" for 8 GPIO SPI version
+ - "mcp,mcp23s17" for 16 GPIO SPI version
+ - "mcp,mcp23008" for 8 GPIO I2C version or
+ - "mcp,mcp23017" for 16 GPIO I2C version of the chip
+- #gpio-cells : Should be two.
+ - first cell is the pin number
+ - second cell is used to specify flags. Flags are currently unused.
+- gpio-controller : Marks the device node as a GPIO controller.
+- reg : For an address on its bus. I2C uses this a the I2C address of the chip.
+ SPI uses this to specify the chipselect line which the chip is
+ connected to. The driver and the SPI variant of the chip support
+ multiple chips on the same chipselect. Have a look at
+ mcp,spi-present-mask below.
+
+Required device specific properties (only for SPI chips):
+- mcp,spi-present-mask : This is a present flag, that makes only sense for SPI
+ chips - as the name suggests. Multiple SPI chips can share the same
+ SPI chipselect. Set a bit in bit0-7 in this mask to 1 if there is a
+ chip connected with the corresponding spi address set. For example if
+ you have a chip with address 3 connected, you have to set bit3 to 1,
+ which is 0x08. mcp23s08 chip variant only supports bits 0-3. It is not
+ possible to mix mcp23s08 and mcp23s17 on the same chipselect. Set at
+ least one bit to 1 for SPI chips.
+- spi-max-frequency = The maximum frequency this chip is able to handle
+
+Example I2C:
+gpiom1: gpio@20 {
+ compatible = "mcp,mcp23017";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x20>;
+};
+
+Example SPI:
+gpiom1: gpio@0 {
+ compatible = "mcp,mcp23s17";
+ gpio-controller;
+ #gpio-cells = <2>;
+ spi-present-mask = <0x01>;
+ reg = <0>;
+ spi-max-frequency = <1000000>;
+};