Linux/AM5718: Pinmuxing in U-boot

satheesh kumar32

Part Number: AM5718

Tool/software: Linux

Hi,

We are creating a new design based on AM5718 EVM. Pin-mux for MMC, Ethernet, UART etc are not changed. Some other pin-mux are changed.If I correctly change the pin-mux configuration in U-boot, will the kernel (given with SDK of AM5718 EVM) boot correctly ?

Regards

Satheesh Kumar S

over 7 years ago

0 Kemal R. Shakir over 7 years ago

TI__Guru 55345 points

Hello Satheesh,

Yes, it should boot. Please, also read this similar thread.

Best regards,
Kemal

0 satheesh kumar32 over 7 years ago in reply to Kemal R. Shakir

Expert 1045 points

Hello

Thanks for your reply

As I'm new to linux, I have some more doubts regarding this.

If I do not need to access those pins in u-boot for which pin-muxing was changed in custom board, do I need to modify pin-muxing in DTS only?

Or is pin-muxing needed in U-bbot level?

Regards

Satheesh Kumar S

0 Kemal R. Shakir over 7 years ago in reply to satheesh kumar32

TI__Guru 55345 points

You need to change the pinmuxes in both places <Processor SDK>/board-support/u-boot-<version>/board/ti/am57xx/mux_data.h and your board's device tree in <Processor SDK>/board-support/u-boot-<version>/arch/arm/dts/.

0 Ahmad_Rashed over 7 years ago in reply to Kemal R. Shakir

TI__Genius 13567 points

Actually,
For AM57x series there is no pin muxing done in the device tree. There is the exception for MMC and recent SDK releases have made that transparent, i.e. all pin muxing is to be done via u-boot mux_data.h file.

Regards,
Ahmad

0 satheesh kumar32 over 6 years ago in reply to Ahmad_Rashed

Expert 1045 points

Hello

I have modified the mux_data.h with minimal setting mmc, Ethernet(RGMII0,I2C1 and UART3). After new u-bot binary,Ethenet1(RGMII1) ,PRU2eth0 and PRU2eth1 are still working. Plz Help.

0312.mux_data.h

Regards

Satheesh Kumar S

0 satheesh kumar32 over 6 years ago in reply to Ahmad_Rashed

Expert 1045 points

Hello

I have modified the mux_data.h with minimal setting mmc, Ethernet(RGMII0,I2C1 and UART3). After new u-bot binary,Ethenet1(RGMII1) ,PRU2eth0 and PRU2eth1 are still working. Plz Help.

4718.mux_data.h

Regards

Satheesh Kumar S

0 Kemal R. Shakir over 6 years ago in reply to satheesh kumar32

TI__Guru 55345 points

Hello Satheesh,

Can you tell us, what are you trying to achieve by changing the pinmuxes?

Best regards,
Kemal

0 Rakesh Muralidharan over 6 years ago in reply to Kemal R. Shakir

Expert 2810 points

1. As we are new to embedded Linux environment . Here we are trying to get control over pinmuxing. Try to find out where all we need to do modification to port Linux to custom board with AM5718. AS of now we have just idk kits to experiment with.

2. Our custom board will also have the following interfaces as in AM5718 idk. So would like to know how to port Linux and whether the board will wake up with minimum interfaces (mmc , UART3 & Eth0,GMDIO GMAC SW0 , I2C1) . If no then where the problems would pop -up and identify traps.

WE believe that same problems we would encounter when porting Linux to custom board.

0 satheesh kumar32 over 6 years ago in reply to Rakesh Muralidharan

Expert 1045 points

Hello Kemal R. Shakir

Thanks for your reply

As rakesh mensioned,which part of sdk actually need modification needed?.From last experiment,we concluded that modification of mux_data.h is not sufficint for custom board porting. Please give valuable suggestions

Regards

Satheesh Kumar S

0 Ahmad_Rashed over 6 years ago in reply to satheesh kumar32

TI__Genius 13567 points

Hi Satheesh,

I think your next step is to disable those modules in the device tree for Linux. Then recompile the dtb and replace it in the /boot/ directory of Linux. Pin muxing is just the routing of the signal from a module within the chip to external pins. Enabling and disabling a module is separate to this.

Regards,
Ahmad

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Linux/AM5718: Pinmuxing in U-boot