Re: [PATCH] arm64: dts: ti: k3-am62a7-sk: Disable mmc Schmitt Trigger

From: Alexander Sverdlin

Date: Wed Jan 07 2026 - 09:49:15 EST


Hi Markus,

On Tue, 2026-01-06 at 18:25 +0100, Alexander Sverdlin wrote:
> >   main_mmc1_pins_default: main-mmc1-default-pins {
> >   pinctrl-single,pins = <
> > - AM62AX_IOPAD(0x23c, PIN_INPUT, 0) /* (A21) MMC1_CMD */

this is a bit trial-and-error, but maybe you could try to add missing clock
retimer/loopback pin for test instead of disabling ST? Would this help:

AM62AX_IOPAD(0x238, PIN_INPUT, 0) /* (N/A) MMC1_CLKLB */

some SoCs from AM6x family seem to require it even though TRMs claim the default
PoR state is the proper one.

> > - AM62AX_IOPAD(0x234, PIN_INPUT, 0) /* (B22) MMC1_CLK */
> > - AM62AX_IOPAD(0x230, PIN_INPUT, 0) /* (A22) MMC1_DAT0 */
> > - AM62AX_IOPAD(0x22c, PIN_INPUT, 0) /* (B21) MMC1_DAT1 */
> > - AM62AX_IOPAD(0x228, PIN_INPUT, 0) /* (C21) MMC1_DAT2 */
> > - AM62AX_IOPAD(0x224, PIN_INPUT, 0) /* (D22) MMC1_DAT3 */
> > - AM62AX_IOPAD(0x240, PIN_INPUT, 0) /* (D17) MMC1_SDCD */
>
> All of these have ST enabled on PoR, according to TRM.
>
> > + AM62AX_IOPAD(0x23c, PIN_INPUT_NOST, 0) /* (A21) MMC1_CMD */
> > + AM62AX_IOPAD(0x234, PIN_INPUT_NOST, 0) /* (B22) MMC1_CLK */
> > + AM62AX_IOPAD(0x230, PIN_INPUT_NOST, 0) /* (A22) MMC1_DAT0 */
> > + AM62AX_IOPAD(0x22c, PIN_INPUT_NOST, 0) /* (B21) MMC1_DAT1 */
> > + AM62AX_IOPAD(0x228, PIN_INPUT_NOST, 0) /* (C21) MMC1_DAT2 */
> > + AM62AX_IOPAD(0x224, PIN_INPUT_NOST, 0) /* (D22) MMC1_DAT3 */
> > + AM62AX_IOPAD(0x240, PIN_INPUT_NOST, 0) /* (D17) MMC1_SDCD */
> >   >;
> >   bootph-all;
> >   };

--
Alexander Sverdlin.