2                VPBE V4L2 driver design
   3 ======================================================================
   5 File partitioning
   6 -----------------
   7 V4L2 display device driver
   8         drivers/media/video/davinci/vpbe_display.c
   9         drivers/media/video/davinci/vpbe_display.h
  11 VPBE display controller
  12         drivers/media/video/davinci/vpbe.c
  13         drivers/media/video/davinci/vpbe.h
  15 VPBE venc sub device driver
  16         drivers/media/video/davinci/vpbe_venc.c
  17         drivers/media/video/davinci/vpbe_venc.h
  18         drivers/media/video/davinci/vpbe_venc_regs.h
  20 VPBE osd driver
  21         drivers/media/video/davinci/vpbe_osd.c
  22         drivers/media/video/davinci/vpbe_osd.h
  23         drivers/media/video/davinci/vpbe_osd_regs.h
  25 Functional partitioning
  26 -----------------------
  28 Consists of the following (in the same order as the list under file
  29 partitioning):-
  31 1. V4L2 display driver
  32    Implements creation of video2 and video3 device nodes and
  33    provides v4l2 device interface to manage VID0 and VID1 layers.
  35 2. Display controller
  36    Loads up VENC, OSD and external encoders such as ths8200. It provides
  37    a set of API calls to V4L2 drivers to set the output/standards
  38    in the VENC or external sub devices. It also provides
  39    a device object to access the services from OSD subdevice
  40    using sub device ops. The connection of external encoders to VENC LCD
  41    controller port is done at init time based on default output and standard
  42    selection or at run time when application change the output through
  43    V4L2 IOCTLs.
  45    When connected to an external encoder, vpbe controller is also responsible
  46    for setting up the interface between VENC and external encoders based on
  47    board specific settings (specified in board-xxx-evm.c). This allows
  48    interfacing external encoders such as ths8200. The setup_if_config()
  49    is implemented for this as well as configure_venc() (part of the next patch)
  50    API to set timings in VENC for a specific display resolution. As of this
  51    patch series, the interconnection and enabling and setting of the external
  52    encoders is not present, and would be a part of the next patch series.
  54 3. VENC subdevice module
  55    Responsible for setting outputs provided through internal DACs and also
  56    setting timings at LCD controller port when external encoders are connected
  57    at the port or LCD panel timings required. When external encoder/LCD panel
  58    is connected, the timings for a specific standard/preset is retrieved from
  59    the board specific table and the values are used to set the timings in
  60    venc using non-standard timing mode.
  62    Support LCD Panel displays using the VENC. For example to support a Logic
  63    PD display, it requires setting up the LCD controller port with a set of
  64    timings for the resolution supported and setting the dot clock. So we could
  65    add the available outputs as a board specific entry (i.e add the "LogicPD"
  66    output name to board-xxx-evm.c). A table of timings for various LCDs
  67    supported can be maintained in the board specific setup file to support
  68    various LCD displays.As of this patch a basic driver is present, and this
  69    support for external encoders and displays forms a part of the next
  70    patch series.
  72 4. OSD module
  73    OSD module implements all OSD layer management and hardware specific
  74    features. The VPBE module interacts with the OSD for enabling and
  75    disabling appropriate features of the OSD.
  77 Current status:-
  79 A fully functional working version of the V4L2 driver is available. This
  80 driver has been tested with NTSC and PAL standards and buffer streaming.
  82 Following are TBDs.
  84 vpbe display controller
  85    - Add support for external encoders.
  86    - add support for selecting external encoder as default at probe time.
  88 vpbe venc sub device
  89    - add timings for supporting ths8200
  90    - add support for LogicPD LCD.
  92 FB drivers
  93    - Add support for fbdev drivers.- Ready and part of subsequent patches.
  94 kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.