lkml.org 
[lkml]   [2015]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v3 1/3] mmc: core: Add mmc_regulator_set_vqmmc()
From
Ulf,

On Mon, Dec 15, 2014 at 4:22 PM, Doug Anderson <dianders@chromium.org> wrote:
> This adds logic to the MMC core to set VQMMC. This is expected to be
> called by MMC drivers like dw_mmc as part of (or instead of) their
> start_signal_voltage_switch() callback.
>
> A few notes:
>
> * When setting the signal voltage to 3.3V we do our best to make VQMMC
> and VMMC match. It's been reported that this makes some old cards
> happy since they were tested back in the day before UHS when VQMMC
> and VMMC were provided by the same regulator. A nice side effect of
> this is that we don't end up on the hairy edge of VQMMC (2.7V),
> which some EEs claim is a little too close to the minimum for
> comfort.
>
> * When setting the signal voltage to 1.8V or 1.2V we aim for that
> specific voltage instead of picking the lowest one in the range.
>
> * We very purposely don't print errors in mmc_regulator_set_vqmmc().
> There are cases where the MMC core will try several different
> voltages and we don't want to pollute the logs.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
> ---
> Changes in v3: None
> Changes in v2:
> - Now use existing regulator_set_voltage_tol() function.
>
> drivers/mmc/core/core.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/mmc/host.h | 7 +++++++
> 2 files changed, 58 insertions(+)

Do you know the status of this patch and its partner patch (mmc:
dw_mmc: Use mmc_regulator_set_vqmmc in start_signal_voltage_switch -
https://patchwork.kernel.org/patch/5498551/)?

I'm happy to repost them or address feedback.

Thanks! :)

-Doug


\
 
 \ /
  Last update: 2015-02-25 22:01    [W:0.292 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site