Commit 02532ba5 authored by Judith Mendez's avatar Judith Mendez Committed by Vignesh Raghavendra
Browse files

arm64: dts: ti: k3-am62l3-evm: Disable MMC1 internal pulls on data pins 

AM62L EVM has external 47K pullups on MMC1 DAT1-DAT3 pins [0].
Disable internal pullups on DAT1-DAT3 so that each line has a
single pullup source:
- with both pullups enabled, the effective parallel resistance on
  DAT1-3 (~24.2K) creates a ~2x mismatch vs DAT0 (47K external
  only). Removing internal pullups results in DAT1-3 matching DAT0 at 47K
- 47K external alone is within the recommended range for 1.8V
  signaling (10K min, 50K recommended max)
- both internal and external pullups enabled equals unnecessary power
  consumption

[0] https://www.ti.com/lit/zip/SPRCAL6



Fixes: 00fb4c73 ("arm64: dts: ti: k3-am62l: add initial reference board file")
Signed-off-by: default avatarJudith Mendez <jm@ti.com>
Reviewed-by: default avatarMoteen Shah <m-shah@ti.com>
Link: https://patch.msgid.link/20260223233731.2690472-3-jm@ti.com


Signed-off-by: default avatarVignesh Raghavendra <vigneshr@ti.com>
parent 6d4441be

arch/arm64/boot/dts/ti/k3-am62l3-evm.dts

+3 −3
Original line number Diff line number Diff line
@@ -272,9 +272,9 @@ mmc1_pins_default: mmc1-default-pins { 
			AM62LX_IOPAD(0x0230, PIN_INPUT, 0) /* (Y3) MMC1_CMD */

			AM62LX_IOPAD(0x0228, PIN_OUTPUT, 0) /* (Y2) MMC1_CLK */

			AM62LX_IOPAD(0x0224, PIN_INPUT, 0) /* (AA1) MMC1_DAT0 */

			AM62LX_IOPAD(0x0220, PIN_INPUT_PULLUP, 0) /* (Y4) MMC1_DAT1 */

			AM62LX_IOPAD(0x021c, PIN_INPUT_PULLUP, 0) /* (AA2) MMC1_DAT2 */

			AM62LX_IOPAD(0x0218, PIN_INPUT_PULLUP, 0) /* (AB2) MMC1_DAT3 */

			AM62LX_IOPAD(0x0220, PIN_INPUT, 0) /* (Y4) MMC1_DAT1 */

			AM62LX_IOPAD(0x021c, PIN_INPUT, 0) /* (AA2) MMC1_DAT2 */

			AM62LX_IOPAD(0x0218, PIN_INPUT, 0) /* (AB2) MMC1_DAT3 */

			AM62LX_IOPAD(0x0234, PIN_INPUT, 0) /* (B6) MMC1_SDCD */

		>;

		bootph-all;