diff options
author | Lars Poeschel <poeschel@lemonage.de> | 2014-01-16 11:44:15 +0100 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2014-01-17 15:30:14 +0100 |
commit | 4e47f91bf741e011a90ceb6241b8d78141709733 (patch) | |
tree | 1febf3cbbf59a1202dc5d944d392ce28b6b851fe /Documentation/devicetree/bindings | |
parent | 785acec3eecf4c21bab9e24afb5d354b57a72e03 (diff) | |
download | blackbird-op-linux-4e47f91bf741e011a90ceb6241b8d78141709733.tar.gz blackbird-op-linux-4e47f91bf741e011a90ceb6241b8d78141709733.zip |
gpio: mcp23s08: Add irq functionality for i2c chips
This adds interrupt functionality for i2c chips to the driver.
They can act as a interrupt-controller and generate interrupts, if
the inputs change.
This is tested with a mcp23017 chip on an arm based platform.
v3:
- be a bit more clear that the irq functionality is also available
on spi versions of the chips, but the linux driver does not support
this yet
v2:
- some more word about irq-mirror property in binding doc
- use of_read_bool instead of of_find_property for
"interrupt-contrller" and "irq-mirror"
- cache the "interrupt-controller" for remove function
- do set the irq-mirror bit only if device is marked as
interrupt-controller
- do create the irq mapping and setup of irq_desc of all possible
interrupts in probe path instead of in gpio_to_irq
- mark gpios as in use as interrupts in irq in irq_startup and
unlock it in irq_shutdown
- rename virq to child_irq
- remove dev argument from mcp23s08_irq_setup function
- move gpiochip_add before mcp23s08_irq_setup in probe path
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 | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt index daa30174bcc1..3ddc7ccfe5f3 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt @@ -38,12 +38,38 @@ Required device specific properties (only for SPI chips): removed. - spi-max-frequency = The maximum frequency this chip is able to handle -Example I2C: +Optional properties: +- #interrupt-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. +- interrupt-controller: Marks the device node as a interrupt controller. +NOTE: The interrupt functionality is only supported for i2c versions of the +chips. The spi chips can also do the interrupts, but this is not supported by +the linux driver yet. + +Optional device specific properties: +- microchip,irq-mirror: Sets the mirror flag in the IOCON register. Devices + with two interrupt outputs (these are the devices ending with 17 and + those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and + IO 8-15 are bank 2. These chips have two different interrupt outputs: + One for bank 1 and another for bank 2. If irq-mirror is set, both + interrupts are generated regardless of the bank that an input change + occured on. If it is not set, the interrupt are only generated for the + bank they belong to. + On devices with only one interrupt output this property is useless. + +Example I2C (with interrupt): gpiom1: gpio@20 { compatible = "microchip,mcp23017"; gpio-controller; #gpio-cells = <2>; reg = <0x20>; + + interrupt-parent = <&gpio1>; + interrupts = <17 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells=<2>; + microchip,irq-mirror; }; Example SPI: |