This allows us to drop a bunch of ugly hacks and finally implement
what

commit cc464b2a
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri Jan 25 16:59:16 2013 -0200

    drm/i915: set TRANSCODER_EDP even earlier

tried to achieve, but that was reverted again in

commit bba2181c
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Mar 22 10:53:40 2013 +0100

    Revert "drm/i915: set TRANSCODER_EDP even earlier"

Now we should always have a consistent cpu_transcoder in the
pipe_config.

v2: Fix up the code as spotted by Paulo:
- read the register for real
- assign the right pipes
- break out if the hw state doesn't make sense

v3: Shut up gcc.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With this, that 338 can finally become the correct 337500.

Due to the change we need to adjust the intel_dp_aux_ch function to
set the correct value, so adjust the division and also use
DIV_ROUND_CLOSEST instead of the old "round down" behavior because the
spec says the value "should be programmed to get as close as possible
to the ideal rate of 2MHz".

Quoting Paulo's follow-up to a question from Chris Wilson to explain
what exactly will change:

I use the 337500 value on the next patch, when setting the
ips_linetime value. The correct frequency is 337500, not 338000.

ips_linetime = DIV_ROUND_CLOSEST(mode->htotal * 1000 * 8,
intel_ddi_get_cdclk_freq);
For a mode with htotal of 2640 [0] we'll have: (i) (2640 * 1000 * 8) /
338000 = 62.48, resulting in 62 and (ii) (2640 * 1000 * 8) / 337500 =
62.57 resulting in 63.

For the case inside intel_dp.c:
Previously we were using 338. So with the old formula we were writing
338/2 = 169 to the register. And 337500 / 169 = 1997.04 (we use 337500
here because it's the real clock value). With the new value of
337500/2000 we'll have 168.75, which is 168 on the round-down case and
169 on the round-closest case. If we write 168 to the register, 337500
/ 168 = 2008.92, and 2008.92 is more distant from 2000 than 1997.04.
So with this patch we're changing the formula but still writing the
same correct value to the DP AUX register.

[0]: That's 1920x1080@50Hz on my DP monitor.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Pimp the commit message with Paulo's follow-up.]
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We can use this for fetching encoder specific pipe_config state, like
mode flags, adjusted clock, etc.

Just used for mode flags atm, so we can check the pipe config state at
mode set time.

v2: get_config when checking hw state too
v3: fix DVO and LVDS mode flags (Ville)
    get SDVO DTD for flag fetch (Ville)
v4: use input timings (Ville)
    correct command used (Ville)
    remove gen4 check (Ville)
v5: get DDI flag config too
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v4)
Tested-by: Paulo Zanoni <przanoni@gmail.com> (the new hsw ddi stuff)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Up to now, we were using a static table to match the clock frequency
with a (r2,n2,p) triplet. Despite this table being big, it's by no mean
comprehensive and we had to fall back to the closest frequency when the
requested TMDS clock wasn't in the table.

This patch computes (r2,n2,p) dynamically and get rid of The Big Table.

v2: Replace the floating point constant 1e6 by 1000000

Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=58497Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
[danvet: s/        /^T/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We did not mention the workaround name when implementing those. This
should help us track what we already implement.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We already have the same check on intel_enable_ddi. This patch
prevents "unclaimed register" messages when the power well is
disabled.

V2: Reset intel_crtc->eld_vld to false after the mode_set function.
V3: Add both "type != INTEL_OUTPUT_EDP" requested.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

dp_init_connector adjusts the encoder type if it is a eDP panel. Use
that to decide whether we should set up a hdmi connector or not.

To do so reorder the hdmi connector setup sequence in ddi_init a bit.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

According to BSpec the link training sequence for eDP on HSW port-A
should be as follows:

1. link training: clock recovery
2. link training: equalization
3. link training: set idle transmission mode
4. display pipe enable
5. link training: disable (set normal mode)

Contrary to this at the moment we don't do step 3. and we do step 5.
before step 4. Fix this by setting idle transmission mode for eDP at
the end of intel_dp_complete_link_train and adding a new
intel_dp_stop_link_training function to disable link training. With
these changes we'll end up with the following functions corresponding
to the above steps:

intel_dp_start_link_train    -> step 1.
intel_dp_complete_link_train -> step 2., step 3.
intel_dp_stop_link_train     -> step 5.

For port-A we'll call intel_dp_stop_link_train only after enabling the
pipe, for everything else we'll call it right after
intel_dp_complete_link_train to preserve the current behavior.

Tested on HSW/HSW-ULT.

In v2:
- Due to a HW issue we must set idle transmission mode for port-A too
  before enabling the pipe. Thanks for Arthur Runyan for explaining
  this.
- Update the patch subject to make it clear that it's an eDP fix, DP is
  not affected.

v3:
- rename intel_dp_link_train() to intel_dp_set_link_train(), use 'val'
  instead 'l' as var name. (Paulo)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we ever leak a non-DP compliant port width through here, we have a
pretty serious issue. So just rip out all these WARNs - if we need
them it's probably better to have them at a central place where we
compute the dp lane count.

Also use the new DDI width macro for FDI mode.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: fixup the embarrassing s/intel_dp->DP/temp/ mistake Paulo
spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Introduce some nice #defines for the FDI lane width fields and put
them to good use. Suggested by Ville.

v3: Fixup the mask vs. shift copy&pasta fail Imre Deak spotted, and
use the shift #define also in the mask.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need this for two reasons:
- Correct handling of shared fdi lanes on ivb with fastboot.
- Handling fdi link bw limits when we only have two fdi lanes by
  dithering down a bit.

Just search&replace in this patch, no functional change at all.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And put the pfit stuff into substructs while we're at it.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We are trying to have more platform-orthogonal pieces of code. The DDI
code shouldn't mention Haswell.

v2: Fix the email address
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Alway use the alphabetical names in debug/error messages for planes,
pipes and ports, instead of using decimal numbers occasionally.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For a bunch of reason we need to more accurately track this:
- hw pipe state readout for Haswell needs the cpu transcoder.
- We need to know the right cpu transcoder in a bunch of places in
  ->disable and other modeset callbacks.

In the future we need to add hw state readout&check support, too. But
to avoid ugly merge conflicts do the rote sed job now without any
functional changes.

v2: Preserve the cpu_transcoder value when overwriting crtc->config.
Reported by Paulo.

Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
[danvet: Removed rough whitespace that Chris spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we couldn't find a pipe we shouldn't return true.  This might be even
better as a WARN though, since it should be impossible to have the port
enabled without a pipe selected.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The procedure has now 3 steps:

1. Compute the bpp that the plane will output, this is done in
   pipe_config_set_bpp and stored into pipe_config->pipe_bpp. Also,
   this function clamps the pipe_bpp to whatever limit the EDID of any
   connected output specifies.
2. Adjust the pipe_bpp in the encoder and crtc functions, according to
   whatever constraints there are.
3. Decide whether to use dither by comparing the stored plane bpp with
   computed pipe_bpp.

There are a few slight functional changes in this patch:
- LVDS connector are now also going through the EDID clamping. But in
  a 2nd change we now unconditionally force the lvds bpc value - this
  shouldn't matter in reality when the panel setup is consistent, but
  better safe than sorry.
- HDMI now forces the pipe_bpp to the selected value - I think that's
  what we actually want, since otherwise at least the pixelclock
  computations are wrong (I'm not sure whether the port would accept
  e.g. 10 bpc when in 12bpc mode). Contrary to the old code, we pick
  the next higher bpc value, since otherwise there's no way to make
  use of the 12 bpc mode (since the next patch will remove the 12bpc
  plane format, it doesn't exist).

Both of these changes are due to the removal of the

	pipe_bpp = min(display_bpp, plane_bpp);

statement.

Another slight change is the reworking of the dp bpc code:
- For the mode_valid callback it's sufficient to only check whether
  the mode would fit at the lowest bpc.
- The bandwidth computation code is a bit restructured: It now walks
  all available bpp values in an outer loop and the codeblock that
  computes derived values (once a good configuration is found) has been
  moved out of the for loop maze. This is prep work to allow us to
  successively fall back on bpc values, and also correctly support bpc
  values != 8 or 6.

v2: Rebased on top of Paulo Zanoni's little refactoring to use more
drm dp helper functions.

v3: Rebased on top of Jani's eDP bpp fix and Ville's limited color
range work.

v4: Remove the INTEL_MODE_DP_FORCE_6BPC #define, no longer needed.

v5: Remove intel_crtc->bpp, too, and fix up the 12bpc check in the
hdmi code. Also fixup the bpp check in intel_dp.c, it'll get reworked
in a later patch though again.

v6: Fix spelling in a comment.

v7: Debug output improvements for the bpp computation.

v8: Fixup 6bpc lvds check - dual-link and 8bpc mode are different
things!

v9: Reinstate the fix to properly ignore the firmware edp bpp ... this
was lost in a rebase.

v10: Both g4x and vlv lack 12bpc pipes, so don't enforce that we have
that. Still unsure whether this is the way to go, but at least 6bpc
for a 8bpc hdmi output seems to work.

v11: And g4x/vlv also lack 12bpc hdmi support, so only support high
depth on DP. Adjust the code.

v12: Rebased.

v13: Split out the introduction of pipe_config->dither|pipe_bpp, as
requested from Jesse Barnes.

v14: Split out the special 6BPC handling for DP, as requested by Jesse
Barnes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to compute this earlier. To avoid a big complicated patch,
this patch here just does the big search&replace and still calls the
old functions at the same places.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is used way too often in the enable/disable paths. And will
be even more useful in the future.

Note that correct semantics of this change highly depend upon
correct updating of intel_crtc->config: Like with all other
modeset state, we need to call ->disable with the old config,
but ->mode_set and ->enable with the new config.

v2: Do not yet use the flag in the ->disable callbacks - atm we don't
yet have support for the information stored in the pipe_config in the
hw state readout code, so this will be wrong at boot-up/resume.

v3: Rebased on top of the hdmi/dp ddi encoder merging.

v4: Fixup stupid rebase error which lead to a NULL vfunc deref.

v5: On haswell the VGA port is on the PCH!

v6: s/IS_HASWELL/HAS_DDI/, spotted by Paulo Zanoni. Also add a missing
parameter name in a function declaration.

v7: Don't forget to git add ...
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If TRANS_DDI_FUNC_CTL has been wrongly programmed with an incorrect
port, we are currently trying to read PORT_CLK_SEL(port) with an
uninitialized value.

Handle that case by returning PORT_CLK_SEL_NONE and warning about it.

v2: Move the warning inside intel_ddi_get_crtc_pll (Paulo Zanoni)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We are really talking about the transcoder function here and the disable
version uses trancoder in its name already, so let's try to be
consistent.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Our static analysis tool noticed that 'reg' could be used uninitialized if
we are trying to get a PLL to drive VGA and SPLL is already in use
(plls->spll_refcoung != 0).

In the (error) case above, let's return false to the caller and emit an
error.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Our mode set sequence documentation says audio must be disabled first.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Resolve conflict since the first patch in this series isn't
applied yet. Also bikeshed commit message as suggested by Ben.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Need to initialize the variable wait to false.
Signed-off-by: NSyam Sidhardhan <s.syam@samsung.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Some (but not all) of the HDMI registers can be used to control sDVO,
so those registers have two names. IMHO, when we're talking about
HDMI, we really should call the HDMI control register "hdmi_reg"
instead of "sdvox_reg", otherwise we'll just confuse people reading
our code (we now have platforms with HDMI but without SDVO). So now
"struct intel_hdmi" has a member called "hdmi_reg" instead of
"sdvox_reg".

Also, don't worry: "struct intel_sdvo" still has a member called
"sdvo_reg".

v2: Rebase (v1 was sent in May 2012).
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similarly to:

  commit 6a0d1df3d3a0d2370541164eb0595fe35dcd6de3
  Author: Damien Lespiau <damien.lespiau@intel.com>
  Date:   Tue Dec 11 15:18:28 2012 +0000

      drm/i915: Preserve the FDI line reversal override bit on CPT

DDI port support lane reversal to easy the PCB layouting work. Let's
preserve the bit configured by the BIOS (until we find how to correctly
retrieve the information from the VBT, but this does sound more fragile
then just relying on the BIOS that has, hopefully, been validated
already.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The FDI link has supported link reversal to make the PCB layout
engineer's life easier for quite a while and we have always presered
this bit as we programmed FDI_RX_CTL with a read/modify/write sequence.

We're trying to take a bit more control over what the BIOS leaves in
various register and with the introduction of DDI, started to program
FDI_RX_CTL fully.

There's a fused bit to indicate DMI link reversal and FDI defaults to
mirroring that configuration. We have a bit to override that behaviour
that we need to preserve from the BIOS.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that the driver is in control of whether it needs to disable
everything at take-over or not, we can rip this all out.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We can disable (almost) all the display hw if we only use pipe A, with
the integrated edp transcoder on port A. Because we don't set the cpu
transcoder that early (yet), we need to help us with a trick to simply
check for any edp encoders.

v2: Paulo Zanoni pointed out that we also need to configure the eDP
cpu transcoder correctly.

v3: Made by Paulo Zanoni
  - Rebase patch to be on top of "fix intel_init_power_wells" patch
  - Fix typos
  - Fix a small bug by adding a "connectors_active" check
  - Restore the initial code that unconditionally enables the power
    well when taking over from the BIOS

v4: Made by Paulo Zanoni
  - One more typo spotted by Jani Nikula

v5: Made by Paulo Zanoni
  - Rebase
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ELD info should be updated dynamically according to hot plug event.
For haswell chip, clear/set the eld valid bit and output enable bit
from callback intel_disable/eanble_ddi().
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NWang Xingchao <xingchao.wang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we fail to set the bit when needed we get some nice FDI link
training failures (AKA "black screen on VGA output").

While we don't really know how to properly choose whether we need to
set the bit or not (VBT?), just read the initial value set by the BIOS
and store it for later usage.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We were previously doing exactly what the "mode set sequence for CRT"
document mandates, but whenever we failed to train the link in the
first tentative, all the other subsequent retries always failed. In
one of my monitors that has 47 modes, I was usually getting around 3
failures when running "testdisplay -a".

After this patch, even if we fail in the first tentative, we can
succeed in the next ones. So now when running "testdisplay -a" I see
around 3 times the message "FDI link training done on step 1" and no
failures.

Notice that now the "retry" code looks a lot like the DP retry code.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- __iomem where there is none (I love how we mix these things up).
- Use gfp_t instead of an other plain type.
- Unconfuse one place about enum pipe vs enum transcoder - for the pch
  transcoder we actually use the pipe enum. Fixup the other cases
  where we assign the pipe to the cpu transcoder with explicit casts.
- Declare the mch_lock properly in a header.

There is still a decent mess in intel_bios.c about __iomem, but heck,
this is x86 and we're allowed to do that.

Makes-sparse-happy: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Use a space after the cast consistently and fix up the
newly-added cast in i915_irq.c to properly use __iomem.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Do an early return in case we don't have DDI instead of having the
whole function inside an "if" statement.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And use it whenever we call code that uses the DDIs. We already have
intel_ddi.c and prefix every function with intel_ddi_something instead of
haswell_something, so I think replacing the checks with HAS_DDI makes more
sense. Just a cosmetical change, yes I know, but I have this OCD...
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's not even declared on header files.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For now, this code is just used by the eDP AUX channel frequency.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds the missing code to send ELD for Haswell DisplayPort,
based on Xingchao's original patch.

A test was performed with HSW-D machine and NEC EA232Wmi DP monitor.

Cc: Xingchao Wang <xingchao.wang@intel.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This covers the "Disable FDI" section from the CRT mode set sequence.
This disables the FDI receiver and also the FDI pll.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This commit makes hsw_fdi_link_train responsible for implementing
everything described in the "Enable and train FDI" section from the
Hawell CRT mode set sequence documentation. We completely rewrite
hsw_fdi_link_train to match the documentation and we also call it in
the right place.

This patch was initially sent as a series of tiny patches fixing every
little problem of the function, but since there were too many patches
fixing the same function it got a little difficult to get the "big
picture" of how the function would be in the end, so here we amended
all the patches into a single big patch fixing the whole function.

Problems we fixed:

  1 - Train Haswell FDI at the right time.

    We need to train the FDI before enabling the pipes and planes, so
    we're moving the call from lpt_pch_enable to haswell_crtc_enable
    directly.

    We are also removing ironlake_fdi_pll_enable since the PLL
    enablement on Haswell is completely different and is also done
    during the link training steps.

  2 - Use the right FDI_RX_CTL register on Haswell

    There is only one PCH transcoder, so it's always _FDI_RXA_CTL.
    Using "pipe" here is wrong.

  3 - Don't rely on DDI_BUF_CTL previous values

    Just set the bits we want, everything else is zero. Also
    POSTING_READ the register before sleeping.

  4 - Program the FDI RX TUSIZE register on hsw_fdi_link_train

    According to the mode set sequence documentation, this is the
    right place. According to the FDI_RX_TUSIZE register description,
    this is the value we should set.

    Also remove the code that sets this register from the old
    location: lpt_pch_enable.

  5 - Properly program FDI_RX_MISC pwrdn lane values on HSW

  6 - Wait only 35us for the FDI link training

    First we wait 30us for the FDI receiver lane calibration, then we
    wait 5us for the FDI auto training time.

  7 - Remove an useless indentation level on hsw_fdi_link_train

    We already "break" when the link training succeeds.

  8 - Disable FDI_RX_ENABLE, not FDI_RX_PLL_ENABLE

    When we fail the training.

  9 - Change Haswell FDI link training error messages

    We shouldn't call DRM_ERROR when still looping through voltage
    levels since this is expected and not really a failure. So in this
    commit we adjust the error path to only DRM_ERROR when we really
    fail after trying everything.

    While at it, replace DRM_DEBUG_DRIVER with DRM_DEBUG_KMS since
    it's what we use everywhere.

  10 - Try each voltage twice at hsw_fdi_link_train

    Now with Daniel Vetter's suggestion to use "/2" instead of ">>1".
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Applied tiny bikesheds:
- mention in comment that we test each voltage/emphasis level twice
- realing arguments of the only untouched reg write, it spilled over
  the 80 char limit ...]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>