cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
wanna
Participant
Participant
540 Views
Registered: ‎08-12-2020

how to use dpdma in linux?

Ok,I have some video data at DDR memory,similar to a framebuffer.Now, I want to use dpdma to move data to Display Port and display in linux. I refer baremetal dpdma code and linux device tree, I directly mmap register address of dpdma to linux userspace and configure it,but I failed, can you give me some suggestion,thank you!

0 Kudos
6 Replies
florentw
Moderator
Moderator
448 Views
Registered: ‎11-09-2015

HI @wanna 

There should be a driver in linux so you do not have to configure the registers directly.

The Zynq UltraScale MPSoC Base TRD is using the Displayport Controller with the DPDMA you might want to have a look on how it is working


Florent
Product Application Engineer - Xilinx Technical Support EMEA
**~ Don't forget to reply, give kudos, and accept as solution.~**
0 Kudos
wanna
Participant
Participant
400 Views
Registered: ‎08-12-2020

@florentw 

Thank you for reply my post; I haven't found any code about the  Zynq UltraScale MPSoC Base TRD, dpdma driver is exist in linux, I should how to use; 

0 Kudos
wanna
Participant
Participant
399 Views
Registered: ‎08-12-2020

I use petalinux version is 2018.3 and  zcu104 board. 

0 Kudos
florentw
Moderator
Moderator
360 Views
Registered: ‎11-09-2015

Hi @wanna 

Unfortunately the TRD is the only the resource I know showing an example using the DPDMA. But keep in mind again that this is using the driver so there is no code in the userspace. This is all managed at framework level


Florent
Product Application Engineer - Xilinx Technical Support EMEA
**~ Don't forget to reply, give kudos, and accept as solution.~**
0 Kudos
wanna
Participant
Participant
354 Views
Registered: ‎08-12-2020

@florentw 

OK, Thanks, your meaning that I should  operate  in linux driver layers rather than user layer when I want to use dpdma driver.  can v4l2 driver solve the problem?  or need myself to edit a driver to invoke dpdam driver.

0 Kudos
florentw
Moderator
Moderator
347 Views
Registered: ‎11-09-2015

Hi @wanna 

Because this is associated with the Dp controller, you need to use the DRM KMS driver.

Then you can control the flow using Gstreamer


Florent
Product Application Engineer - Xilinx Technical Support EMEA
**~ Don't forget to reply, give kudos, and accept as solution.~**
0 Kudos