* Nishanth Menon <nm@xxxxxx> [150925 07:38]:
> On 09/25/2015 08:02 AM, Tomi Valkeinen wrote:
> > LDO1 regulator (VDD_SD) is connected to SoC's vddshv8. vddshv8 needs to
> > be kept always powered (see commit 5a0f93c6576a ("ARM: dts: Add
> > am57xx-beagle-x15"), but at the moment VDD_SD is enabled/disabled
> > depending on whether an SD card is inserted or not.
> >
> > This patch sets LDO1 regulator to always-on.
> >
> > This patch has a side effect of fixing another issue, HDMI DDC not
> > working when SD card is not inserted:
> >
> > Why this happens is that the tpd12s015 (HDMI level shifter/ESD
> > protection chip) has LS_OE GPIO input, which needs to be enabled for the
> > HDMI DDC to work. LS_OE comes from gpio6_28. The pin that provides
> > gpio6_28 is powered by vddshv8, and vddshv8 comes from VDD_SD.
> >
> > So when SD card is not inserted, VDD_SD is disabled, and LS_OE stays
> > off.
> >
> > The proper fix for the HDMI DDC issue would be to maybe have the pinctrl
> > framework manage the pin specific power.
> >
> > Apparently this fixes also a third issue (copy paste from Kishon's
> > patch):
> >
> > ldo1_reg in addition to being connected to the io lines is also
> > connected to the card detect line. On card removal, omap_hsmmc
> > driver does a regulator_disable causing card detect line to be
> > pulled down. This raises a card insertion interrupt and once the
> > MMC core detects there is no card inserted, it does a
> > regulator disable which again raises a card insertion interrupt.
> > This happens in a loop causing infinite MMC interrupts.
> >
> > Fixes: 5a0f93c6576a ("ARM: dts: Add am57xx-beagle-x15")
> > Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
> > Reported-by: Louis McCarthy <compeoree@xxxxxxxxx>
>
> Acked-by: Nishanth Menon <nm@xxxxxx>
Applying into omap-for-v4.3/fixes thanks.
Tony
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