The I2C pins for some of the instances on J784S4/J742S2/AM69 are
configured as PIN_INPUT_PULLUP while these pins are open-drain type and
do not support internal pull-ups [0][1][2]. The pullup configuration
bits in the corresponding padconfig registers are reserved and any
writes to them have no effect and readback checks on those bits fail.

Update the pinmux settings to use PIN_INPUT instead of PIN_INPUT_PULLUP
to reflect the correct hardware behaviour.

[0]: https://www.ti.com/lit/gpn/tda4ah-q1 (J784S4 Datasheet: Table 5-1. Pin Attributes)
[1]: https://www.ti.com/lit/gpn/tda4ape-q1 (J742S2 Datasheet: Table 5-1. Pin Attributes)
[2]: https://www.ti.com/lit/gpn/am69a (AM69 Datasheet: Table 5-1. Pin Attributes)

Fixes: e20a06aca5c9 ("arm64: dts: ti: Add support for J784S4 EVM board")
Fixes: 635fb18ba008 ("arch: arm64: dts: Add support for AM69 Starter Kit")
Fixes: 0ec1a48d99dd ("arm64: dts: ti: k3-am69-sk: Add pinmux for RPi Header")
Signed-off-by: Aniket Limaye <a-limaye@ti.com>
Reviewed-by: Udit Kumar <u-kumar1@ti.com>
---
v3:
- Collected Udit's "Reviewed by:" from v1
- Link to v2: https://lore.kernel.org/lkml/20251022121222.220113-1-a-limaye@ti.com/

v2:
- Added Fixes tags
- Link to v1: https://lore.kernel.org/lkml/20251019103938.276062-1-a-limaye@ti.com/
---
 arch/arm64/boot/dts/ti/k3-am69-sk.dts                   | 8 ++++----
 arch/arm64/boot/dts/ti/k3-j784s4-j742s2-evm-common.dtsi | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am69-sk.dts b/arch/arm64/boot/dts/ti/k3-am69-sk.dts
index 5896e57b5b9e..0e2d12cb051d 100644
--- a/arch/arm64/boot/dts/ti/k3-am69-sk.dts
+++ b/arch/arm64/boot/dts/ti/k3-am69-sk.dts
@@ -236,8 +236,8 @@ J784S4_IOPAD(0x0d4, PIN_OUTPUT, 11) /* (AN38) SPI0_CLK.UART8_TXD */
 
 	main_i2c0_pins_default: main-i2c0-default-pins {
 		pinctrl-single,pins = <
-			J784S4_IOPAD(0x0e0, PIN_INPUT_PULLUP, 0) /* (AN36) I2C0_SCL */
-			J784S4_IOPAD(0x0e4, PIN_INPUT_PULLUP, 0) /* (AP37) I2C0_SDA */
+			J784S4_IOPAD(0x0e0, PIN_INPUT, 0) /* (AN36) I2C0_SCL */
+			J784S4_IOPAD(0x0e4, PIN_INPUT, 0) /* (AP37) I2C0_SDA */
 		>;
 	};
 
@@ -416,8 +416,8 @@ J784S4_WKUP_IOPAD(0x088, PIN_OUTPUT, 0) /* (J37) WKUP_GPIO0_12.MCU_UART0_TXD */
 
 	mcu_i2c0_pins_default: mcu-i2c0-default-pins {
 		pinctrl-single,pins = <
-			J784S4_WKUP_IOPAD(0x0a0, PIN_INPUT_PULLUP, 0) /* (M35) MCU_I2C0_SCL */
-			J784S4_WKUP_IOPAD(0x0a4, PIN_INPUT_PULLUP, 0) /* (G34) MCU_I2C0_SDA */
+			J784S4_WKUP_IOPAD(0x0a0, PIN_INPUT, 0) /* (M35) MCU_I2C0_SCL */
+			J784S4_WKUP_IOPAD(0x0a4, PIN_INPUT, 0) /* (G34) MCU_I2C0_SDA */
 		>;
 	};
 
diff --git a/arch/arm64/boot/dts/ti/k3-j784s4-j742s2-evm-common.dtsi b/arch/arm64/boot/dts/ti/k3-j784s4-j742s2-evm-common.dtsi
index 419c1a70e028..2834f0a8bbee 100644
--- a/arch/arm64/boot/dts/ti/k3-j784s4-j742s2-evm-common.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-j784s4-j742s2-evm-common.dtsi
@@ -270,8 +270,8 @@ J784S4_IOPAD(0x0d4, PIN_OUTPUT, 11) /* (AN38) SPI0_CLK.UART8_TXD */
 
 	main_i2c0_pins_default: main-i2c0-default-pins {
 		pinctrl-single,pins = <
-			J784S4_IOPAD(0x0e0, PIN_INPUT_PULLUP, 0) /* (AN36) I2C0_SCL */
-			J784S4_IOPAD(0x0e4, PIN_INPUT_PULLUP, 0) /* (AP37) I2C0_SDA */
+			J784S4_IOPAD(0x0e0, PIN_INPUT, 0) /* (AN36) I2C0_SCL */
+			J784S4_IOPAD(0x0e4, PIN_INPUT, 0) /* (AP37) I2C0_SDA */
 		>;
 	};
 
-- 
2.51.0

Hi Aniket Limaye,

On Wed, 22 Oct 2025 17:56:33 +0530, Aniket Limaye wrote:
> The I2C pins for some of the instances on J784S4/J742S2/AM69 are
> configured as PIN_INPUT_PULLUP while these pins are open-drain type and
> do not support internal pull-ups [0][1][2]. The pullup configuration
> bits in the corresponding padconfig registers are reserved and any
> writes to them have no effect and readback checks on those bits fail.
> 
> Update the pinmux settings to use PIN_INPUT instead of PIN_INPUT_PULLUP
> to reflect the correct hardware behaviour.
> 
> [...]

I have applied the following to branch ti-next on [1].
Thank you!

[1/1] arm64: dts: ti: k3-j784s4: Fix I2C pinmux pull configuration
      commit: 671c852fc53d1b6f5eccdb03c1889a484c9d1996

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
--
Vignesh