imx7d EPDC pin mux issue

[econote_vikrant]

Greetings!

I have attached an image of MSO readings of EPDC SDDO for screen flash (black -> white -> black -> white).

I am using Eink panel with 16-bit SDDO width with imx7dsabre board, according to an operation of EPDC black and white screen 16-bit data must be 0x5555 and 0xAAAA respectively.

I would like to know are my EPDC pin number 7,12 and 14 being used (or muxed) by some other feature in imx7d? If yes then kindly suggest me how to assign it for EPDC only. I have already made changes in the device tree for the EPDC feature.

[igorpadykov]

Hi Vikrant

for "black -> white" testing one can try unit test mxc_fb_test and framebuffer panning test
mxc_epdc_v2_fb_test.c\mxc_fb_test\test - imx-test - i.MX Driver Test Application Software 
For custom panel may be required special waveform file specific to E Ink panel, for
details one can refer to sect.6.4.5.8 Using a Custom Waveform File attached Linux Manual.

For testing one can use IMXEBOOKDC4 card and follow Table 11. Common kernel boot parameters

attached Release Notes.

>I would like to know are my EPDC pin number 7,12 and 14 being used (or muxed) by some other feature in imx7d?

one can look how these signals are used checking i.MX7D Sabre SD schematic:

Schematics (2)
Design files for i.MX 7Dual (REV D)
Design files, including hardware schematics, Gerbers, and OrCAD files for i.MX 7Dual (REV D)
i.MX 7Dual Applications Processors | Dual Arm® Cortex®-A7 + Cortex-M4 | NXP 

Best regards
igor
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