Toggling gpio pins while powering down

Andrew Lunn andrew at lunn.ch
Wed Feb 12 02:57:43 EST 2014


On Tue, Feb 11, 2014 at 07:33:11PM +0000, Jasbir Matharu wrote:
> I'm trying to determine the correct way of toggling gpio pins when the
> soc is powering down to enter low power mode. My current crude
> implementation is perform these within a pm_power_off function however
> this is currently done within the board file by checking for a
> compatible board type (ugly). The alternative would be create a driver
> and implement the pm_power_off function within. However given there
> could many drivers implementing a pm_power_off functions there's no
> guarantee mine will be called? Another requirement is that the gpio
> need to be set in the correct order.

Have you seen:

drivers/power/reset/gpio-poweroff.c

It currently only allows for a single gpio, but it would not be too
hard to extend it for multiple gpios.

     Andrew




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