Ulf, On Mon, Dec 15, 2014 at 4:22 PM, Doug Anderson <dianders@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> > Reviewed-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
