How to use VDMA on a running linux?

jackolus · ‎07-21-2016

Hello,

I'm a newbie so take it easy on me.

I've used the https://github.com/analogdevicesinc/hdl to build a design with hdmi monitor and I added an IP for image processing that I generated with vivado HLS and a VDMA to transfer data between my ip and the ddr.

I've tested the design on sdk with a standalone application and it is working fine. Now I want to run my application on a running linux on my zc702( I'm using an sd card with 2 partitions: Linaro FS and one for booting files).

I've seen that people are using <sys/mman.h> to communicate with the PL blocs like :

void configureVDMA(unsigned long vdma_physical_base)
{
	unsigned long int PhysicalAddress = vdma_physical_base ;
	int map_len = 0x20;
	int fd = open( "/dev/mem", O_RDWR);
	unsigned char* vdma_base_address;
	vdma_base_address = (unsigned char*)mmap(NULL, map_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, (off_t)PhysicalAddress);
	if(vdma_base_address == MAP_FAILED)
	{
		perror("VDMA Mapping memory for absolute memory access failed.\n");
		return;
	}
	DEBUG_Printf ("VDMA mapping 0x%x to 0x%x, size = %d\n ", (int )PhysicalAddress, (int)vdma_base_address, map_len );

        .....

	munmap((void *)vdma_base_address, map_len);
	close(fd);
}

But I got the failed message.

I don't know but should I add drivers to the kernel image "uImage" for PL blocs? and if yes, should I add drivers for both the HLS IP and VDMA?

I need your help plz

watari · ‎07-21-2016

Hi jackolus

Could you make sure whether device tree blob file is correct or not ?

Also, could you show me device tree source file ?

Thank you.

Best regards

jackolus · ‎07-21-2016

Here it is watari

watari · ‎07-21-2016

Hi jackolus

Could you execute the following commands on your linux and show me the result ?

% ls /proc/device-tree/amba

% ls -l /proc/device-tree/amba_pl

% ls /boot/

Thank you

Best regards,

jackolus · ‎07-21-2016

I tried the commands and here are the results:

% ls /proc/device-tree/amba

% ls -l /proc/device-tree/amba_pl

there was no "amba_pl" in the device-tree directory

% ls /boot/

was empty

watari · ‎07-21-2016

Hi jackolus

I confirmed your uploaded information.

According to them, the description of device tree source file and the result of "ls /proc/device-tree/amba" and "ls /proc/device-tree/amba_pl" are different.

It's very strange.

Could you explain how to generate device tree blob file to me ?

or

Could you make sure device tree blob file ?

I'm probably sure that the route cause is wrong device tree blob file.

Thank you.

Best regards,

jeffdaq · ‎07-22-2016

You don't have to add drivers to the kernel if you are going to write userspace drivers using mmap. If you don't have anything in the amba_pl directory it means you device tree is not correct. Are you sure the system.dts is including your dtsi file?

jeff

jackolus · ‎07-25-2016

Thank you both jeffdaq and watari, you are correct the problem was in the devicetree I've been using the https://github.com/analogdevicesinc/linux.git devicetree (sorry I feel stupid now).

However, now I'm having another problem. I'm using SDK to build my devicetree and when I tested it the hdmi monitor isn't working, I'm able to access the filesystem through uart but the hdmi isnt working.

Could the problem be the audio because when booting, I used to get:

ALSA device list:

#0: HDMI monitor

...

However now I'm getting

ALSA device list:

No soundcards found.

...

watari · ‎07-25-2016

Hi jackolus

Could you show me your block diagram for HDMI ?

Also, how do you generate output clock frequency at HDMI ?

Thank you.

Best regards,

jackolus · ‎07-26-2016

Hello watari,

Thank you for responding.

I couldn't attatch my block design so here it is https://drive.google.com/open?id=0BzR7agsHdJabbGxpUGpodVMzVkE.

However, can you please check if I am building the devicetree correctly?

I'm using this repository : https://github.com/Xilinx/device-tree-xlnx

and the default settings :

execpt for bootargs I'm using: console=ttyPS0,115200 root=/dev/mmcblk0p2 rw earlyprintk rootfstype=ext4 rootwait

Am I doing something wrong?

watari · ‎07-26-2016

Hi jackolus

I can't access https://drive.google.com/open?id=0BzR7agsHdJabbGxpUGpodVMzVkE.

Could you show me block diagram ?

Also could you show me device tree source file, what you want to build and result by "ls" command, if you want that I confirm it ?

Thank you.

Best regards,

jackolus · ‎08-04-2016

Hello watari,

Here is he design and the files generated by SDK to form the device tree.

watari · ‎08-09-2016

Hi jackolus

I mention to you.

1) HDMI issue

I guess you connect HDMI monitor via HDMA calue with AUX/Audio.

Hence you find this message.

> ALSA device list:

> #0: HDMI monitor

> ...

> However now I'm getting

2) device-tree issue

I already confirmed your uploaded files.

You define axi_vdma_0 in pl.dtsi file.

However, I can't find this definition in your posted picutre which is generated by "ls /proc/device-tree/amba" and "ls /proc/device-tree/amba_pl" to make sure recognition of device tree.

Hence I suspect you have mistake to generate device tree blob file.

Could you execute the following command to make sure the definition of device tree ?

% dtc -I dtb -O dts -o <output dts file name> <input dtb file name>

After that, you get "<output dts file name>" file as device tree source file and you can confirm it.

Could you confirm it, too ?

Thank you.

Best regards,

jackolus · ‎08-10-2016

Hello watari,

Thank you for responding.

The pictures I've posted where when I was using the analogdevicesinc from github. Now I'm generating my own devicetree using SDK and here are the results: