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>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 858d489..2d49784 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -722,6 +722,7 @@
SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017
I/O expanders.
This provides a GPIO interface supporting inputs and outputs.
+ The I2C versions of the chips can be used as interrupt-controller.
config GPIO_MC33880
tristate "Freescale MC33880 high-side/low-side switch"