This adds embedded DisplayPort support on next mobile chip which
aims to replace origin LVDS port. VBT's driver feature block has
been used to determine the type of current internal panel for eDP
or LVDS.

Currently no panel fitting support for eDP and backlight control
would be added in future.
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

We should use current channel 'status' bits to clear DP aux channel's
done and error bits, instead of using the channel setting bits, that
will set send/busy bit again to initiate new transaction.

This also includes also some minor cleanup.
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

Convert many printk calls to DRM_DEBUG calls to reduce kernel log noise
for normal activities. Switch other printk calls to DRM_ERROR or DRM_INFO.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

The display port aux channel clock is taken from the hrawclk value, which is
provided to the chip as the FSB frequency (as far as I can determine). The
strapping values for that are available in the CLKCFG register, now used to
select an appropriate divider to generate a 2MHz clock.

In addition, the DisplayPort spec requires that each aux channel I/O be
retried 'at least 3 times' in case the sink is idle when the first request
comes in.
Signed-off-by: NKeith Packard <keithp@keithp.com>

Use distinct error return values for each kind of aux channel I/O failure.
Signed-off-by: NKeith Packard <keithp@keithp.com>

When a DP monitor is plugged back in, it needs to be retrained if it was
active before.
Signed-off-by: NKeith Packard <keithp@keithp.com>

Signed-off-by: NKeith Packard <keithp@keithp.com>