OMAP2+ Display Subsystem support.
The amount of SDRAM to reserve at boot time for video RAM use. This VRAM will be used by omapfb and other drivers that need large continuous RAM area for video use. You can also set this with "vram=<bytes>" kernel argument, or in the board file.
This enables debug messages. You need to enable printing with 'debug' module parameter.
Collect DSS IRQ statistics, printable via debugfs. The statistics can be found from <debugfs>/omapdss/dispc_irq for DISPC interrupts, and <debugfs>/omapdss/dsi_irq for DSI interrupts.
DPI Interface. This is the Parallel Display Interface.
MIPI DBI support (RFBI, Remote Framebuffer Interface, in Texas Instrument's terminology). DBI is a bus between the host processor and a peripheral, such as a display or a framebuffer chip. See http://www.mipi.org/ for DBI spesifications.
OMAP Video Encoder support for S-Video and composite TV-out.
HDMI Interface. This adds the High Definition Multimedia Interface. See http://www.hdmi.org/ for HDMI specification.
SDI (Serial Display Interface) support. SDI is a high speed one-way display serial bus between the host processor and a display.
MIPI DSI (Display Serial Interface) support. DSI is a high speed half-duplex serial interface between the host processor and a peripheral, such as a display or a framebuffer chip. See http://www.mipi.org/ for DSI spesifications.
If this is selected, DSI will generate a fake DISPC VSYNC interrupt when DSI has sent a frame. This is only needed with DSI or RFBI displays using manual mode, and you want VSYNC to, for example, time animation.
This can be used to adjust the minimum FCK/PCK ratio. With this you can make sure that DISPC FCK is at least n x PCK. Video plane scaling requires higher FCK than normally. If this is set to 0, there's no extra constraint on the DISPC FCK. However, the FCK will at minimum be 2xPCK (if active matrix) or 3xPCK (if passive matrix). Max FCK is 173MHz, so this doesn't work if your PCK is very high.
For some unknown reason we may get SYNC_LOST errors from the display subsystem at initialization time if we don't sleep before resetting the DSS. See the source (dss.c) for more comments. However, 50ms is quite long time to sleep, and with some configurations the SYNC_LOST may never happen, so the sleep can be disabled here.
There is a 20ms sleep after VENC reset which seemed to fix the reset. The reason for the bug is unclear, and it's also unclear on what platforms this happens. This option enables the sleep, and is enabled by default. You can disable the sleep if it doesn't cause problems on your platform.