[i2c] [PATCH 2.6.24-rc4-mm 2/2] gpiolib: add Generic IRQ support for 16-bit PCA9539 GPIO expander

[David Brownell]

On Monday 10 December 2007, eric miao wrote:
> +config GPIO_PCA9539_GENERIC_IRQ
> +       bool "    Generic IRQ support for PCA9539"
> +       depends on GPIO_PCA9539=y

Also depends on GENERIC_HARDIRQS, right?  (You should let
the Kconfig UI handle indentation, too...)

Seems like doing this for an I2C chip ought to shake loose
some interesting review comments.  :)


> +       help
> +         Say yes here to support the Generic IRQ for the PCA9539 on-chip
> +         GPIO lines.

This somewhat resembles the pcf857x chips in that it only support
pin-changed IRQs (IRQ_TYPE_EDGE_BOTH) in hardware.  Some other I/O
expanders are a bit more flexible.

- Dave