PAD Mux in u-boot and kernel

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PAD Mux in u-boot and kernel

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1,261 Views
rans
Senior Contributor I

Hello,

I see there are pad mux in u-boot board file, and also in kernel device tree files.

Both seems to be about the same.

So, Why is it that both are required ? Why can't u-boot pad also keep on when moving to kernel ?

I am afraid that there might be some differences between both.

Is it that CONFIG_PINMUX shall disable the override of mux in kernel ?

Thank you,

Ran

1 Solution
966 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ran

u-boot pad configs can keep on when moving to kernel using dts settings

described in linux/Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt:

Bits used for CONFIG:
NO_PAD_CTL(1 << 31): indicate this pin does not need config.

linux-imx.git - i.MX Linux Kernel 

Since uboot and kernel may be used with other os&bootladers, so seems both pad mux 

are used.

Best regards
igor
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1 Reply
967 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ran

u-boot pad configs can keep on when moving to kernel using dts settings

described in linux/Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt:

Bits used for CONFIG:
NO_PAD_CTL(1 << 31): indicate this pin does not need config.

linux-imx.git - i.MX Linux Kernel 

Since uboot and kernel may be used with other os&bootladers, so seems both pad mux 

are used.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------