Re: [edk2-devel] [PATCH v3 6/7] Platform/RaspberryPi: Power up sd, and tweak GPIOs

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 1/4/21 6:37 PM, Jeremy Linton wrote:
> It seems we should be powering up the sd cards, and possibly
> the clocks as well to assure they are setup properly before
> we attempt to access the controller.
> 
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> Reviewed-by: Andrei Warkentin <awarkentin@vmware.com>
> ---
>  Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> index 28f57438c5..e55ed63efa 100644
> --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
> @@ -552,6 +552,16 @@ ApplyVariables (
>        GpioPinFuncSet (37, GPIO_FSEL_ALT3);
>        GpioPinFuncSet (38, GPIO_FSEL_ALT3);
>        GpioPinFuncSet (39, GPIO_FSEL_ALT3);
> +
> +      /*
> +       * power and clock everything by default

Isn't this comment a bit exaggerated? You only power the minimum
required to use the SD controller to access the card.

> +       */
> +      Status = mFwProtocol->SetPowerState (RPI_MBOX_POWER_STATE_SDHCI,
> +                                           TRUE, TRUE); //SD on with wait
> +      Status = mFwProtocol->SetGpioConfig (RPI_EXP_GPIO_SD_VOLT, 
> +                                           RPI_EXP_GPIO_DIR_OUT, TRUE); //3.3v
> +      Status = mFwProtocol->SetClockState (RPI_MBOX_CLOCK_RATE_EMMC2, TRUE);
> +      Status = mFwProtocol->SetClockState (RPI_MBOX_CLOCK_RATE_EMMC, TRUE);
>      }
>    } else {
>      DEBUG ((DEBUG_ERROR, "Model Family %d not supported...\n", mModelFamily));
>