On Thu, Jun 20, 2019 at 03:07:19PM +0530, Faiz Abbas wrote:
During a short period when the bus voltage is switched from 3.3v to 1.8v, (to enumerate UHS mode), the mmc module is disabled and the mmc IO lines are kept in a state according to the programmed pad mux pull type.
According to 4.2.4.2 Timing to Switch Signal Voltage in "SD Specifications Part 1 Physical Layer Specification Version 5.00 February 22, 2016", the host should hold CLK low for at least 5ms.
In order to keep the card line low during voltage switch, the pad mux of mmc1_clk line should be configured to pull down.
Add a new pinctrl group for clock line without pullup to be used in boards where mmc1_clk line is not connected to an external pullup.
Signed-off-by: Faiz Abbas faiz_abbas@ti.com
Applied to u-boot/master, thanks!