Re: [PATCH v2 2/2] imx: kontron-sl-mx8mm: Enable PCA9450 regulator driver and fix SD card access

Fabio Estevam
2022-06-28T10:52:10Z

On Mon, Jun 27, 2022 at 8:01 AM Frieder Schrempf <frieder@fris.de> wrote:
>
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>
> Currently accessing the SD card on USDHC2 fails with:
>
> => mmc dev 1
> Card did not respond to voltage select! : -110
>
> This is due to the fact that UHS modes are enabled in the defconfig
> and the devicetree, but the referenced LDO5 regulator (reg_nvcc_sd)
> is not available to switch the data lines from 3.3V to 1.8V mode.
>
> By enabling the regulator driver the vqmmc-supply is now available
> and the SD card works also in high speed modes:
>
> => mmc dev 1
> switch to partitions #0, OK
> mmc1 is current device
>
> Please note that the board has a GPIO connected to the SD_VSEL signal
> of the PMIC. As the driver uses the LDO5CTRL_H register to set the
> voltage, we need to make sure that this GPIO (GPIO01_IO4) is set to
> a high level.
>
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> Reviewed-by: Fabio Estevam <festevam@denx.de>

Tested-by: Fabio Estevam <festevam@denx.de>