Linux/66AK2G02: u-boot PCIe endpoint support

Stephen Turner

Part Number: 66AK2G02

Tool/software: Linux

We are looking at the 66AK2G02 for a new design. We will be using u-boot to init the PCIe interface as an endpoint before passing control of the SoC to the DSP.

We previously used the DM8147 and its u-boot has PCIe support. We have not been able to find PCIe support in the 66AK2G02 u-boot so far. Maybe we are looking at the wrong branch?. Can some one confirm if this exists or is planned?.

thanks

over 8 years ago

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi Stephen,

It's not enabled, but sources & cmd drivers are available. I am not sure if we've verified the pcie driver in u-boot.

Can you try the following:
Add the appropriate definitions in include/configs/k2hk_evm.h looking at drivers/pci/Kconfig :
config DM_PCI
config DM_PCI_COMPAT
config PCI_SANDBOX

Then to enable u-boot commands, you can check cmd/pci.c. Commands are enabled, if you have CONFIG_DM_PCI set in k2hk_evm.h.

Best Regards,
Yordan

0 Stephen Turner over 8 years ago in reply to Yordan Kovachev

Genius 3476 points

Hi Yordan,

We have looked, but don't seem to be able to find the PCIe code in the 66AK2G0x u-boot. Can you point us to the location of the source tree?.

thanks

Steve

0 Yordan Kovachev over 8 years ago in reply to Stephen Turner

TI__Guru**** 161600 points

Hi Steve,

Look for the following directory:
<path/to/u-boot>/drivers/pci

This should be available in the latest SDK:

Best Regards,

Yordan

0 Stephen Turner over 8 years ago in reply to Yordan Kovachev

Genius 3476 points

Hi Yordan,

We have looked in the u-boot source from the latest SDK, but cannot find the directory/drivers/pci.

regards

0 Yordan Kovachev over 8 years ago in reply to Stephen Turner

TI__Guru**** 161600 points

Hi Stephen,

Do you download the ti-processor-sdk-linux-k2g-evm-03.03.00.04-Linux-x86-Install.bin from the link above and install the sources? Maybe the binary fails to install the sdk sources completely.
I just did the above & the directory drivers/pci exists.

Anyway, I am looping the sw team to elaborate if necessary.

Best Regards,
Yordan

0 Rex Chang over 8 years ago in reply to Yordan Kovachev

TI__Guru 50170 points

Hi, Stephen,

I hope this post does not confuse you further, but clarify your question. The PCIe in u-boot is not supported and is considered as a new feature request.

As far as the K2G Linux Kernel is concerned, the PCIe EP mode is not support yet, only RC. The EP mode support is targeted at 2H17.

Rex

0 Stephen Turner over 8 years ago in reply to Rex Chang

Genius 3476 points

Hi Rex,

No, I understand the state of things:

u-boot: no PCIe support

Linux: PCIe RC support only

Question is, can TI add u-boot EP support to u-boot?.

thanks!

0 Rex Chang over 8 years ago in reply to Stephen Turner

TI__Guru 50170 points

Hi, Stephen,

If DSP is using it, will it be too late for DSP to init the PCIe EP during system coming up?

I'll submit a request for review. In the past, 2 similar requests, not EP mode, for different platforms were rejected. Let's see if it get approved this time with different application and platform.

Rex

0 Rex Chang over 8 years ago in reply to Rex Chang

TI__Guru 50170 points

HI, Stephen,

I assume the ARM is running Linux in your case, and want to have u-boot to init the PCIe first, correct? Would you be able to provide more info on the application which PCIe EP is used for?

Rex

0 Stephen Turner over 8 years ago in reply to Rex Chang

Genius 3476 points

Hi Rex,

Our application is a PCIe Sound Card.

We use the DSP side of the K2G for audio processing and transfer of audio samples to/from the drivers running on a Windows/Linux PC.

The ARM side is used to init the PCIe bus and load the DSP firmware from the PC driver. Once that is done, it hands control over to the DSP and essentially goes to sleep.

thanks

0 Stephen Turner over 8 years ago in reply to Stephen Turner

Genius 3476 points

I forgot to say that the ARM is running a modified u-boot only. Linux is not being used.

0 Rex Chang over 8 years ago in reply to Stephen Turner

TI__Guru 50170 points

Thanks for the response. The marketing and development teams will review the info. I'll post back either way about their decision.

Rex

0 Rex Chang over 8 years ago in reply to Rex Chang

TI__Guru 50170 points

Hi, Stephen,

When I gave it a deep thought of your application, I figure that you don't really need Linux u-boot to do the job. You can have a startup code using TI RTOS for ARM which configures the PCIe EP mode for your purpose. We have existing PCIe EP mode configuration in RTOS PDK package. You can port it to the startup code. The current RTOS has ARM diagnosis run automatically when the system powers up. The PCIe configuration should be able to tie in to the startup. Do you think this would work?

Rex

0 Rex Chang over 8 years ago in reply to Rex Chang

TI__Guru 50170 points

I meant we have PCIe EP mode example code in RTOS PDK which you can port it from.

Rex

0 Stephen Turner over 8 years ago in reply to Rex Chang

Genius 3476 points

Here are the links for anybody else with the same issue. We will look at porting this to u-boot

<gitorious.ti.com/.../pcie_sample.c>
<gitorious.ti.com/.../pcie_soc.c>

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Linux/66AK2G02: u-boot PCIe endpoint support