U-Boot and internal screen?

MNT Reform
2

I would love to get this to work, I simply didn’t have the time/capacity to do it. Enabling the HDMI solves half of this, basically, because this gets the DCSS engine up and running that can feed the MIPI-DSI output as well (if one mux register bit is flipped). I think two IP blocks and one external chip need to be poked, plus the PWM output for the backlight:

  1. nwl-dsi (internal to i.MX8MQ). Driver: nwl-dsi.c - drivers/gpu/drm/bridge/nwl-dsi.c - Linux source code (v5.13-rc6) - Bootlin
  2. mixel MIPI DPHY (internal to i.MX8MQ). Driver: phy-fsl-imx8-mipi-dphy.c - drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c - Linux source code (v5.13-rc6) - Bootlin (pretty small)
  3. TI sn56dsi86 MIPI->eDP bridge (external, poked via I2C). Driver: ti-sn65dsi86.c - drivers/gpu/drm/bridge/ti-sn65dsi86.c - Linux source code (v5.13-rc6) - Bootlin

The bridge chip also has a “color bars” test register to get some output on the display without a valid input. This could be a good first step.

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