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author | Lars Poeschel <poeschel@lemonage.de> | 2013-04-04 12:02:02 +0200 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2013-04-10 23:41:17 +0200 |
commit | 97ddb1c88b4ebe057b63346660abfee165ddd468 (patch) | |
tree | eff1fc4d226bc72ecc8ca3887552b5477ac9298f /Documentation/devicetree/bindings | |
parent | a2797beadfcb5a0974a30929b613b4d1adb023d1 (diff) | |
download | op-kernel-dev-97ddb1c88b4ebe057b63346660abfee165ddd468.zip op-kernel-dev-97ddb1c88b4ebe057b63346660abfee165ddd468.tar.gz |
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')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt | 47 |
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 new file mode 100644 index 0000000..629d0ef --- /dev/null +++ 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>; +}; |