Messages in this thread |  | | | Date | Sat, 12 Nov 2011 12:00:20 +0100 | | Subject | Re: [PATCH] ARM: SAMSUNG: Save/restore GPIO drive strength across suspend/resume | | From | Linus Walleij <> |
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On Sat, Nov 12, 2011 at 6:01 AM, Inderpal Singh <inderpal.singh@linaro.org> wrote:
> GPIO driver strength settings are not preserved across suspend/resume > for s5pc100, s5pv210 and Exynos platforms which has been the cause of > mmc/sd card read/write failures after resume. Fix this by saving and > restoring the GPIO driver strength register settings across suspend/resume. > > Signed-off-by: Inderpal Singh <inderpal.singh@linaro.org>
On a related theme: I am thinking about how to support preserving drive strength (etc) across suspend/resume and deepsleep in the pincontrol subsystem.
Currently I am playing with the idea to let pin groups have states, as the different configurations seem to be 90% or so about very specific sleep modes, so say:
pinconf_set_group_state("mmcgroup", PINCONF_STATE_ACTIVE); pinconf_set_group_state("mmcgroup", PINCONF_STATE_SUSPENDED); pinconf_set_group_state("mmcgroup", PINCONF_STATE_SLEEP);
This would then instruct each pin controller driver to configure each pin apropriately for the given state, and that cross-references to a table keeping track of the preset per-pin for each state.
My intuitive idea is that letting the core keep track of the state of every pin and letting pin groups harness the settings for a group of pins is the proper approach to the problem.
Do you think something like this will work for the S5P:s?
Yours, Linus Walleij
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