imx-drm changes to use media bus formats and LDB drm_panel support

- Add media bus formats needed by imx-drm
- Switch to use media bus formats to describe the pixel format
  on the internal parallel bus between display interface and
  encoders
- Some preparations for TV Output via TVEv2 on i.MX5
- Add drm_panel support to the i.MX LVDS driver, allow to
  determine the bus pixel format from the panel descriptor.

* tag 'imx-drm-next-2015-03-31' of git://git.pengutronix.de/git/pza/linux:
  drm/imx: imx-ldb: allow to determine bus format from the connected panel
  drm/imx: imx-ldb: reset display clock input when disabling LVDS
  drm/imx: imx-ldb: add drm_panel support
  drm/imx: consolidate bus format variable names
  drm/imx: switch to use media bus formats
  Add RGB666_1X24_CPADHI media bus format
  Add YUV8_1X24 media bus format
  Add BGR888_1X24 and GBR888_1X24 media bus formats
  Add LVDS RGB media bus formats
  Add RGB444_1X12 and RGB565_1X16 media bus formats
  drm/imx: ipuv3-crtc: Allow to divide DI clock from TVEv2
  drm/imx: Add support for interlaced scanout

The value for downsizing 8:1 is marked as reserved in the technical reference
manual and the documentation states downsizing capability up to 4:1 only.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

The DI pixel clock divider bit field is only 8 bits wide for the
integer part, so limit the divider to the 1...255 interval before
deciding whether the internal clock can be used and before writing
to the register.

Reported-by: Felix Mellmann <felix.mellmann@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

This patch consolidates the different interface_pix_fmt, pixel_fmt, pix_fmt,
and pixfmt variables to a common name "bus_format" wherever they describe the
pixel format on the bus between display controller and encoder hardware.
At the same time, it renames imx_drm_panel_format to imx_drm_set_bus_format.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Emil Renner Berthing <kernel@esmil.dk>

imx-drm internally misused the V4L2_PIX_FMT constants, which are supposed to
describe the pixel format of frame buffers in memory, to describe the pixel
format on the bus between the display controller and the encoder hardware.
Now that MEDIA_BUS_FMT constants are available to drm drivers, use those
instead.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Emil Renner Berthing <kernel@esmil.dk>

Even if an unsupported mode with a pixel clock larger than two times the
264 MHz IPU HSP clock is set, don't divide by zero.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

imx-drm fixes for IPUv3 DC and i.MX5 IPUv3 IC and TVE

- Corrected handling of wait_for_completion_timeout return value
  when disabling IPUv3 DC channels
- Fixed error return value propagation in TVE mode_set
- Fixed IPUv3 register offsets for IC module on i.MX51 and i.MX53

* tag 'imx-drm-fixes-2015-01-28' of git://git.pengutronix.de/git/pza/linux:
  gpu: ipu-v3: Fix IC control register offset
  drm: imx: imx-tve: Check and propagate the errors
  gpu: ipu-v3: wait_for_completion_timeout does not return negative status

The IC register offset is at +0x20000 relative to the control module
registers on all IPUv3 versions. This patch fixes wrong values for
i.MX51 and i.MX53.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

This fixes up the return value handling and the return type.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

We can use the DIV_ROUND_CLOSEST() macro when calculating the DI
clock divider, rounded to nearest int.

Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>