platform: imx8qxp c0 mek
OS: yocto 4.19.35_1.1.0
hardware connection: imx8qxp lvds0 => dummy panel , lvds1 => it6263 => display
On imx8qxp there are one DPU(display process unit) and one ISI(image subsystem interface), ISI supports input from dpu.
dpu block diagram:
note that only dsi0 and lvds0 can be used for loopback.
and this patch only test the lvds0, since lvds support dummy panel.
Please see the readme in the attchment for how to enale this feature.
Note: for ISI loopback, it needs output of 2x GPIO (4x for HDMI-TX or combo PHY) to pixel_link_receiver_address:
For iMX8QM:
o LVDS: pixel_link_receiver_address[1:0] = do_gpio_dr[7:6]
o MIPI-DSI: pixel_link_receiver_address[1:0] = do_gpio_dr[7:6]
o HDMI-TX: odd_pixel_link_receiver_address[1:0] = do_gpio_dr[7:6],even_pixel_link_receiver_address[1:0] = do_gpio_dr[5:4]
For iMX8QXP:
o Combo MIPI-DSI / LVDS: pixel_link0_receiver_address[1:0] = do_gpio_dr[7:6], pixel_link1_receiver_address[1:0] = do_gpio_dr[5:4]
