Unable to detect axi-core-tdd iio device

Hello,

Which Linux branch/devicetree are you using? If you are using the 2022_R2 branch, there have been some recent updates to the driver, you might need to change the compatible name in the devicetree, as it is shown here:
https://github.com/analogdevicesinc/linux/blob/2022_R2/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-rev10-tdd.dts#L37

Thanks,
Ramona

Hi Ramona,

Thanks for your reply! I download the Linux using "git clone https://github.com/analogdevicesinc/linux.git", so I think I use the main branch. I use the "zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dts" devicetree for projects/ad9081_fmca_ebz/zcu102 and use "zynqmp-zcu102-rev10-stingray.dts" for projects/ad9081_fmca_ebz_x_band/zcu102.

In this case, do I need to change the compatible name? Could you tell me more about why I need to change this name? 

Actually, I can detect the tdd device using the hdl documents from here(git clone github.com/.../hdl.git; git switch data_offload) which is part of a tutorial from here.  And I use the same devicetree for this project and projects/ad9081_fmca_ebz/zcu102 of hdl_2022_r2. 

Do you have any idea about this problem?

Best,

Dongyu

Hello Dongyu,

Yes, even if you are using the main branch you should be changing the compatible name in the devicetree.

The reason for this name change is that the driver for adi-axi-tdd was recently upstreamed, and upon some discussions with the maintainers it was decided that 'adi,axi-tdd' was more suitable, as it is included in the documentation: https://github.com/analogdevicesinc/linux/blob/main/Documentation/devicetree/bindings/misc/adi%2Caxi-tdd.yaml#L60 and as it can be seen in the adi-axi-tdd driver file: github.com/.../adi-axi-tdd.c. Unfortuantely, some of the devicetree examples were not updated in this sense, including the one you used. This issue is only on the linux side, and we will update the remaining devicetrees that use tdd to avoid further confusion.

You should be able to see the device in iio after this change.

Thank you,
Ramona

Hi Ramona,

Thanks for your reply!

I met a problem when I re-build the devicetree, the error is as follows:

pci@pci-virtual-machine:~/linux$ make /xilinx/zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dtb
make: *** No rule to make target '/xilinx/zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dtb'.  Stop.

Do you know how to figure it out? Thanks!

Best,

Dongyu

Hello,

It seems you added an extra '/' to the path. It should be just

make xilinx/zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dtb

HI Ramona,

I use your command and there is still the same error. I also try to re-build the Image and Devicetree following the instruction here. The Image can be built successfully but for the devicetree, the same error still occurs. Do you have any idea about this? Actually, I when I first run this command, there are so many options. I use the default choice for the most options. After that, this error occurs.

Best,

Dongyu 

HI Ramona,

I use your command and there is still the same error. I also try to re-build the Image and Devicetree following the instruction here. The Image can be built successfully but for the devicetree, the same error still occurs. Do you have any idea about this? Actually, I when I first run this command, there are so many options. I use the default choice for the most options. After that, this error occurs.

Best,

Dongyu 

Hi Ramona,

I figure out the make error. And I change the tdd name in the devicetree "zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dts"  as follows:

// SPDX-License-Identifier: GPL-2.0
/*
 * Analog Devices AD9081-FMC-EBZ
 * https://wiki.analog.com/resources/eval/user-guides/quadmxfe/quick-start
 * https://wiki.analog.com/resources/tools-software/linux-drivers/iio-mxfe/ad9081
 *
 * hdl_project: <ad9081_fmca_ebz/zcu102>
 * board_revision: <>
 *
 * Copyright (C) 2021 Analog Devices Inc.
 */

#include "zynqmp-zcu102-rev10-ad9081-m8-l4-do.dts"

&axi_data_offload_tx {
	adi,oneshot;
	adi,sync-config = <1>;
};

&axi_data_offload_rx {
	adi,oneshot;
	adi,sync-config = <1>;
};

&fpga_axi {
	axi_tdd_0: axi-tdd-0@9c460000 {
		compatible = "adi,axi-tdd";
		reg = <0x9c460000 0x10000>;
		clocks = <&zynqmp_clk PL0_REF>, <&hmc7044 6>;
		clock-names = "s_axi_aclk", "intf_clk";
	};
};

&axi_ad9081_core_tx {
	adi,axi-pl-fifo-enable;
};

Then I rebuilt the Image and devicetree, but I still cannot detect the adi-tdd device using "iio_attr -d". Do you have any idea about this?
Best,

Dongyu

Hello,

My colleague tested out the devicetree and we figured out why you couldn't see the device with iio_attr. Previously, the tdd driver was an iio driver but after the last update it was moved in misc, and in order to have the device show up in iio you also need to add it as a iio-fake-platform-device. She created a branch with the necessary modifications for your dts, and we tested it out and the device shows up and the attributed can be read/written.

If you build the dtb from this branch: https://github.com/analogdevicesinc/linux/blob/staging/fix-tdd-dts/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dts#L33 , you should also have the device available. Please let us know if you run into any other issues.

Thank you,
Ramona

Hi Ramona,

Thanks for your reply! I have tried this devicetree with Image 2022_R2, HDL generated from hdl_2022_R2. And my hardware include a zcu102 and ad9081. But I still cannot detect the tdd device. Could you send me your system, Image and BOOT.bin files? I wondering if my image and hdl are wrong.

Besides, I noticed that there is the address of your new created device "iio_axu_tdd_0" is 0, is this correct?

Thanks,

Dongyu

Hello Dongyu,

Just to check, after you built your devicetree from the branch, did you rename it to "system.dtb" when moving it to the boot partition of the board? If the devicetree is not name "system.dtb" it will not be loaded. We tried with 2 different build versions of the devicetree and the attributes of tdd can be accessed on our end. Moreover, please make sure you export the architecture and the cross-compiler, and that you also make de configuration adi_zynqmp_defconfig, before each build. Here is an example:

export ARCH=arm64
export CROSS_COMPILE=/opt/Xilinx/Vitis/2022.2/gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-
make adi_zynqmp_defconfig
make xilinzynqmp-zcu102-rev10-ad9081-m8-l4-tdd.dtb

Hi Ramona,

Yeah, my pipeline is the same with what you said. I think maybe my image and boot.bin have something wrong. My email is dd7477@princeton.edu. Could you send these files to me? Thanks so much!

Thanks,

Dongyu