Hell Nvidia team,
we are using Orin nano(8GB) with custom carrier board, with L4T 36.3.
we are using as I2C IO-expander which we need to access from UEFI bootlaoder for writing some value to reset particular IC.
so please suggest us any possible ways to achieve this.
Hi bharath.gk,
Which I2C IO-expander module you are using? I suppose that you need the custom driver to work with your IO-expander.
Have you tried to do that in kernel driver?
Do you get UEFI source for R36.3.0 and you can build it successfuly?
Hi @KevinFFF
MAX7313ATG+T is the io expander we use. please suggest us how we achieve this at UEFI level.
From kernel we have not controlling from driver, but direct i2c-read-write apis we are using from user level.
yes source code and able to customize already as @KevinFFF
suggested here Remove boot logo and add boot progress bar - #15 by bharath.gk
I would suggest using kernel driver to init/control your I2C device.
But you can also refer to the following thread to use I2C in UEFI as your requirement.
Need Uefi to send commands to an I2C device - #5 by KevinFFF
thank you @KevinFFF ,
we will verify and come back to you.
Hello @KevinFFF ,
could you please provide any steps/link to stop boot at UEFI bash to check available command support.
You can select UEFI shell as boot device in UEFI menu.
hi @KevinFFF ,
w.r.t to i2c slave access in UEFI level, we are following this reference , here we are nit able to identify the bus number. its uses EFI_I2C_IO_PROTOCOL,
our requirement is to access a salve ic 0x20 in i2c-1 device.
any suggestions here?
I think &Register is the I2C address of RTC module in the example you are referring.
edk2-nvidia/Silicon/NVIDIA/Library/MaximRealTimeClockLib/MaximRealTimeClockLib.h at main · NVIDIA/edk2-nvidia · GitHub
hello @KevinFFF , we stuck at GUID for Maxim7313, while following similar implementation for maxim7313 IO expander access from UEFI by referring other imlementaion for maxim IC’s which we shared in previous post,
we may have to add similar kind of support in BpmpI2cDxe.c
GLOBAL_REMOVE_IF_UNREFERENCED EFI_GUID gNVIDIAI2cMaxim20024 = { 0xa7f8c208, 0xbe90, 0x4363, { 0x84, 0xc5, 0x1c, 0xc9, 0xed, 0x04, 0xe7, 0x19 } };
we need similar kind GUID for Maxim7313 too, we found above GUID for Maxim20024 in some AutoGen.c,
kindly please suggest where do we need to add that GUID’s and where do we get from.
FYI: we already asked for IC vendor for GUID, they suggested to check in linux driver linux/drivers/gpio/gpio-pca953x.c at main · analogdevicesinc/linux · GitHub but we not found suck guid anywhere.
We don’t have this module and cannot verify each modules on the market so that I can not give you detailed steps to enable them.
It seems there’s example driver in linux kernel for your expander. Why you don’t just use it and configure it in kernel during boot up?
You can still use common I2C Read/Write API from user space after boot up.
hi @KevinFFF , thank you for your reply.
yes we saw a driver for MAXIM7313 IO expander in kernel, but we have requirement in such way that to modify values of particular pin high/low during UEFI stage and then set back in user level.
so we are trying to take control of I2C slave in UEFI.
Sorry that I still don’t know why you have to do it in UEFI instead of kernel.
It seems you open another topic 307551 for the same issue. Let us just discuss there.
yes @KevinFFF we opened separate ticket since the issue was little different from original one, so to avoid confusion we created new one.
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