Some SD Card controller and power circuitry has increased capacitance,
which keeps the internal logic remains powered after regulator is switch
off. This is generally the case when card is switched to SD104 mode,
where a power cycle should be performed. In case if the card internal
logic remains powered, it causes a subsequent failure of mode
transition, effectively leading to failed enumeration.
Introduce a delay of 20 msec in order to provide a possibility for
internal card circuitry to drain voltages and perform a power cycle
correctly.
Similar fix is done in commit c49d0ac38a ("ARM: dts: rmobile: Increase
off-on delay on the SD Vcc regulator") targeted Renesas SOCs.
Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Cc: Stefano Babic <sbabic@denx.de>
Beacon EmbeddedWorks, formerly known as Logic PD, is releasing
a devkit based on the i.MX8M Mini SoC consisting of baseboard +
SOM.
It supports eMMC on the SOM, microSD on the baseboard, various
GPIO, the PINCTRL, and UART.
Signed-off-by: Adam Ford <aford173@gmail.com>
