On Sun, Aug 25, 2019 at 5:06 PM Alejandro González <alejandro.gonzalez.correo@xxxxxxxxx> wrote: > Jernej Skrabec compared the BSP driver with this > driver, and found that the BSP driver configures pinctrl to operate at > 1.8 V when entering DDR mode (although 3.3 V operation is supported), while > the mainline kernel lacks any mechanism to switch voltages dynamically. (...) > the kernel lacks the required > dynamic pinctrl control for now This is not a pin control thing, the I/O voltage level is usually controlled by a regulator called VCCQ, if the selection of the voltage rails is inside the pin control registers, see the solution in drivers/pinctrl/sh-pfc/pfc-sh73a0.c where we simply provide a regulator from inside the pinctrl driver to make things easy for the MMC core. Do this thing! If you don't have time to fix it up properly right now I would slap in a big FIXME in the code so people know this needs to be fixed properly. Yours, Linus Walleij
