Re: [PATCH 1/2] gpiolib: add gpiochip_get_desc() driver function

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Sun, Feb 09, 2014 at 05:43:54PM +0900, Alexandre Courbot wrote:
> Some drivers dealing with a gpio_chip might need to act on its
> descriptors directly; one example is pinctrl drivers that need to lock a
> GPIO for being used as IRQ using gpiod_lock_as_irq().
> 
> This patch exports a gpiochip_get_desc() function that returns the
> GPIO descriptor at the requested index. It also sweeps the
> gpio_to_chip() function out of the consumer interface since any holder
> of a gpio_chip reference can manipulate its GPIOs way beyond what a
> consumer should be allowed to do.
> 
> As a result, gpio_chip is not visible anymore to simple GPIO consumers.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
> Jean-Jacques, I think you will want to use this function for locking GPIOs
> in the AT91 pinctrl driver. Mika, we talked about this a while ago already,
> but here it is finally. Next patch uses it in the GPIO ACPI driver.

This seems to be useful for ACPI GPIO operation region implementation as
well.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>