It looks like on OMAP3 some DSS pins need VDDS_DSI to function properly.

This has not been confirmed from TI, but looking at figure 15-1 "Display
subsystem highlight" from the TRM, some data pins come near the DSI and SDI
blocks. This is not very hard evidence, but the fact remains that with the
power on, pixels are ok, and with the power off, pixels are not ok.

It may also be that VDDS_SDI is needed to power some pins, but as normally
both VDDS_SDI and VDDS_DSI come from the same power source, this hasn't
been shown.

It seems that a single driver can only get a regulator once. This patch
solves it by getting all the required regulators in one place, and from
which the submodules then get the regulators they need.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

Loops checking for certain condition were rather inconsistent.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>
Reported-by: NJuha Leppanen <juha_motorsportcom@luukku.com>

DSI driver didn't check if the panel driver actually implements
enable_te().
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

Collect interrupt statistics, printable via debugfs:

debugfs/omapdss/dispc_irq
debugfs/omapdss/dsi_irq

The counters are reset when printed.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

- dsi_vc_send_short() needs to use dest_per for the peripheral id
- dsi_vc_send_null() was always using channel id 0
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

DSI (Display Serial Interface) driver implements MIPI DSI interface.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>