iMX8QM/QXP Reference Patch to Map Bridge Chip to Display without EDID

Document created by Qiang Li - Mpu Se Employee on May 22, 2019
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In defaut Linux BSP, NXP implemented LVDS to HDMI(it6263) and MIPI-DSI to HDMI(adv7535) bridge chip drivers. And these drivers need read the EDID from display, then apply the timing parameters to DRM driver.

 

But for the use case that bridge chip -> Serializer -> Deserializer -> LCD Panel use case, there is no EDID.

 

The attached are reference patches for such use case, it combined the bridge chip to panel directly, and no EDID is needed.

 

The patches are tested on iMX8QXP MEK with bridge chip + panel mode, both of them can see the fb0 device under /sys/class/graphics/ folder, also can see card under  /sys/class/drm/. Display works fine with DTS selected 720P panel mode.

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