AM3352: Why does kernel's am335x-evmsk.dts use AM33XX_PADCONF() instead of AM33XX_IOPAD() ?

Naoto Uegaki

Part Number: AM3352

AM33XX_IOPAD() is used in "$uboot/arch/arm/dts/am335x-evmsk.dts". Also, AM33XX_IOPAD() is used in "devicetree.dtsi" created by PinMux tool.

In "$kernel/arch/arm/boot/dts/am335x-evmsk.dts", on the other hand, AM33XX_PADCONF() is used. Why does kernel's am335x-evmsk.dts use AM33XX_PADCONF() instead of AM33XX_IOPAD() ?

over 3 years ago

0 Bin Liu over 3 years ago

TI__Guru**** 167481 points

Hi,

The U-Boot DT driver requires the pinmux entry to have two fields, so it uses AM33XX_IOPAD() which is defined as "OMAP_IOPAD_OFFSET((pa), 0x0800) (val)" in U-Boot include/dt-bindings/pinctrl/omap.h.

While Kernel DT driver requires the pinmux entry to have three fields, so it uses AM33xx_PADCONF() which is defined as "OMAP_IOPAD_OFFSET((pa), 0x0800) (conf) (mux)" in kernel include/dt-bindings/pinctrl/omap.h.

0 Naoto Uegaki over 3 years ago in reply to Bin Liu

Intellectual 775 points

Thank you for reply.
Was AM33XX_PADCONF() in "$kernel/arch/arm/boot/dts/am335x-evmsk.dts" automatically created by Pinmux tool ? Moreover, was the first parameter of AM33XX_PADCONF() such as AM335X_PIN_GPMC_AD8 automatically created by Pinmux tool ?

0 Bin Liu over 3 years ago in reply to Naoto Uegaki

TI__Guru**** 167481 points

Hi,

I am routing your query to our Pinmux tool expert for comments.

+1 Fleenor over 3 years ago

TI__Mastermind 22883 points

Hello,

The SysConfig-PinMux Tool currently only supports the U-Boot device tree driver function (AM33XX_IOPAD()). I have submitted a ticket to also enable the creation of the Kernel device tree driver function (AM33XX_PAD_CONF()).

In the meantime it is possible to manually reconstruct the original U-Boot file to meet the Kernel-specific function requirements.

AM33XX_IOPAD(0x8f0, PIN_INPUT_PULLUP | MUX_MODE0)

AM33XX_PADCONF(0x8f0, PIN_INPUT_PULLUP, MUX_MODE0)

An example of this transformation can be found here:

https://patchwork.kernel.org/project/linux-omap/patch/20200919195159.3126193-1-drew@beagleboard.org/#23636719

Regards,

Zackary Fleenor

0 Naoto Uegaki over 3 years ago in reply to Fleenor

Intellectual 775 points

Thank you for reply.
I understood that PinMux tool can create device tree file for U-boot.

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AM3352: Why does kernel's am335x-evmsk.dts use AM33XX_PADCONF() instead of AM33XX_IOPAD() ?