struct drm_rect represents a simple rectangle. The utility
functions are there to help driver writers.

v2: Moved the region stuff into its own file, made the smaller funcs
    static inline, used 64bit maths in the scaled clipping function to
    avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
v3: Renamed drm_region to drm_rect, drm_region_clip to
    drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
v4: Renamed some function parameters, improve kernel-doc comments a bit,
    and actually generate documentation for drm_rect.[ch].
v5: s/RETUTRNS/RETURNS/
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Writing hw registers from compute_config?
Just say no!

In this case not too horrible since we write a constant 0, and only
debugging would put something else in there. But while checking that
code I've noticed that this register disappeared on pch platforms, so
fix that up, too.

And adjust the comment a bit, it's outdated.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was still required a bit (on the cargo-cult side though) when the
state was stored in dev_priv, and when the enable/disable sequence was
botched a bit (to avoid too many updates).

But with pipeconfig we always get a clean slate, so this is pointless.
Rip it out.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

pipe_config is the new dev_priv!

More seriously, this is actually better since a pipe_config can be
thrown away if the modeset compute config stage fails. Whereas any
state stored in dev_prive needs to be painstakingly restored, since
otherwise a dpms off/on will wreak massive havoc. Yes, that even
applies to state only used in ->mode_set callbacks, since we need to
call those even for dpms on when the Haswell power well cleared
everything out.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Both intel_opregion_enable_asle() and intel_enable_asle() have shrunk
considerably. Merge them together into a static function in i915_irq.c,
and rename to better reflect the purpose and the related platforms.

No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Realize that intel_enable_asle() is never called on PCH-split platforms
or on VLV. Rip out the GSE irq enable for PCH-split platforms, which
also happens to be incorrect for IVB+.

This should not cause any functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Stop calling intel_opregion_enable_asle() and consequently
intel_enable_asle() on opregion init. It should not be necessary for
these reasons:

1) On PCH split platforms, it only enables GSE interrupt, which is
   enabled in irq postinstall anyway. Moreover, the irq enable uses the
   wrong bit on IVB+.

2) On gen 2, it would enable a reserved pipestat bit. If there were gen
   2 systems with opregion asle support, that is. And the gen 2 irq
   handler won't handle it anyway.

3) On gen 3-4, the irq postinstall will call
   intel_opregion_enable_asle() to enable the pipestat.

In short, move the asle irq/pipestat enable responsibility to irq
postinstall, which already happens to be in place.

This should not cause any functional changes, but only do the one line
change here for easier bisectability, just in case, and leave all the
cleanups this allows to followup patches.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only set ASLE driver readiness (ARDY) and technology enabled indicator
(TCHE) once per opregion init. There should be no need to do that at irq
postinstall time. Also clear driver readiness at fini.

While at it, add defines for driver readiness.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move near other defines, add TCHE in the name. No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This does duplicate the logic in intel_crtc_mode_get a bit, but the
issue is that we also should handle interlace modes and other insanity
correctly.

Hence I've opted for a sligthly more elaborate route where we first
read out the crtc timings for the adjusted mode, and then optionally
(not sure if we really need it) compute the modeline from that.

v2: Also read out the pipe source dimensions into the requested mode.

v3: Rebase on top of the moved cpu_transcoder.

v4: Simplify CHECK_FLAGS logic as suggested by Chris Wilson. Also
properly #undef that macro again.

Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> (v3)
[danvet: Use the existing mask for interlaced bits, spotted by Mika.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to use the fdi m/n values to easily compute the adjusted mode
dotclock on pch ports. Hence make sure the values stored in the pipe
config are always reliable.

v2: Fixup FDI TU readout.

v3: Rebase on top of moved cpu_transcoder.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This code will get _really_ repetive, and we'll end up with tons more
of this kind. So extract the common patterns.

This should also help when we add a lazy pipe_config compare mode for
fastboot.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Spotted while changing related code.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So on a bunch of setups we only have 2 fdi lanes available, e.g. hsw
VGA or 3 pipes on ivb. And seemingly a lot of modes don't quite fit
into this, among them the default 1080p mode.

The solution is to dither down the pipe a bit so that everything fits,
which this patch implements.

But ports compute their state under the assumption that the bpp they
pick will be the one selected, e.g. the display port bw computations
won't work otherwise. Now we could adjust our code to again up-dither
to the computed DP link parameters, but that's pointless.

So instead when the pipe needs to adjust parameters we need to retry
the pipe_config computation at the encoder stage. Furthermore we need
to inform encoders that they should not increase bandwidth
requirements if possible. This is required for the hdmi code, which
prefers the pipe to up-dither to either of the two possible hdmi bpc
values.

LVDS has a similar requirement, although that's probably only
theoretical in nature: It's unlikely that we'll ever see an 8bpc
high-res lvds panel (which is required to hit the 2 fdi lane limit).

eDP is the only thing which could increase the pipe_bpp setting again,
even when in the retry-loop. This could hit the WARN. Two reasons for
not bothering:
- On many eDP panels we'll get a black screen if the bpp settings
  don't match vbt. So failing the modeset is the right thing to do.
  But since that also means it's the only way to light up the panel,
  it should work. So we shouldn't be able to hit this WARN.
- There are still opens around the eDP panel handling, and maybe we
  need additional tricks. Before that happens it's imo no use trying
  to be too clever.
Worst case we just need to kill that WARN or maybe fail the compute
config stage if the eDP connector can't get the bpp setting it wants.
And since this can only happen with an fdi link in between and so for
pch eDP panels it's rather unlikely to blow up, if ever.

v2: Rebased on top of a bikeshed from Paulo.

v3: Improve commit message around eDP handling with the stuff
things with Imre.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to multiply the hdmi port dotclock by 1.5x since it's not
really a dotclock, but the 10/8 encoding bitclock divided by 10.

Also add correct limit checks for the dotclock and reject modes which
don't fit. HDMI 1.4 would allow more, but our hw doesn't support that
unfortunately :(

Somehow I suspect 12bpc hdmi output never really worked - we really
need an i-g-t testcase to check all the different pixel modes and
outputs.

v2: Fixup the adjusted port clock handling - we need to make sure that
the fdi link code still gets the real pixelclock.

v3: g4x/vlv don't support 12bpc hdmi output so drop the bogus comment.
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Switch dotclock limit check to <= as suggested by Ville.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This allows us to use all 4 fdi lanes on fdi B when the cpu eDP is
running on pipe C. Yay!

v2: Encapsulate test into a little helper function, as suggested by
Chris Wilson.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This nicely allows us to drop some hacks which have only been used
to work around modeset failures due to lack of fdi lanes.

v2: Implement proper checking for Haswell platforms - the fdi link to
the LPT PCH has only 2 lanes. Note that we already filter out
impossible modes in intel_crt_mode_valid. Unfortunately LPT does not
support 6bpc on the fdi rx, so we can't pull clever tricks to squeeze
in a few more modes.

v2: Rebased on top of Ben Widawsky's num_pipes reorg.

v3: Rebase on top of Ville's pipe debug output ocd rampage.

v4: Fixup rebase fail spotted by Ville.

v5: Fixup rebase fail spotted by Imre Deak. I suck.

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>

Again in preparation to move the configuration checks into the
pipe_config computation stage of the modeset sequence.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that it's split up, we can easily move it around and precompute
the fdi lane configuration.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And also move the computed m_n values into the pipe_config. This is a
prep step to move the fdi state computation completely into the
prepare phase of the modeset sequence. Which will allow us to handle
fdi link bw constraints in a better way.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
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>

Totally untested due to lack of screens supporting more than 8bpc. But
now we should have closed all holes in our bpp handling, so this
should be safe. The last missing piece was 10bpc support for g4x/vlv,
since we directly use the pipe bpp to feed the display link (and
anyway, only the cpt has any means to have a pipe bpp != the display
link bpp).
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The current code is rather ... ugly. The only thing it managed to pull
off is getting 6bpc on DP working on g4x. Then someone added another
custom hack for 6bpc eDP on vlv. Fix up this entire mess by properly
implementing the PIPECONF-based dither/bpc controls on g4x/vlv.

Note that compared to pch based platforms g4x/vlv don't support 12bpc
modes. g4x is already caught, extend the check for vlv.

The other fixup is to restrict the lvds-specific dithering to early
gen4 devices - g4x should use the pipeconf dither controls. Note that
on gen2/3 the dither control is in the panel fitter even.

v2: Don't enable dithering when the pipe is in 10 bpc mode. Quoting
from Bspec "PIPEACONF - Pipe A Configuration Register, bit 4":

"Programming note: Dithering should only be enabled for 8 bpc or 6
bpc."

v3: Actually drop the old ugly dither code.

v4: Explain in a short comment why g4x/vlv shouldn't dither for 30 bpp
pipes (Jesse).

v5: Also clear the dither type correctly as spotted by Ville.

v6: As Ville pointed out we need to indeed set the dithering both in
the pipeconf register (for DP outputs) and in the LVDS port register
(for LVDS ouputs). Otherwise LVDS panel will not get properly
dithered. The old patch got away with this since it forgot to clear
the LVDS dither bit ...

v7: Remove redundant BPC_MASK clearing, spotted by Ville.

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

They can get at the adjusted mode through intel_crtc->config.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We've had our fair share of woes already which showed that we can't
rely on the bpc limits in the EDID for eDP panels without risking
black screens. So now we limit the depth by what the BIOS recommends
in the VBT:

commit 2f4f649a
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Nov 12 14:33:44 2012 +0200

    drm/i915: do not ignore eDP bpc settings from vbt

But that's not enough, since at least the panel on my ASUS Zenbook
Prime here is also unhappy if the bpc is too low. Hence just take the
firmware value and dither to get what flimsy panels want.

Like before we ensure that we don't change the bpp if the firmware
doesn't provide a value, see

commit 9a30a61f
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Nov 12 14:33:45 2012 +0200

    drm/i915: do not default to 18 bpp for eDP if missing from VBT

v2: Apparently there are some horribly broken eDP panels around which
only work if the DP link is set up as if we want to driver a 24bpp
mode, but still only work if the data is feed at 18bpp. See

commit 57c21963
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Apr 4 17:19:37 2013 +0200

    drm/i915: revert eDP bpp clamping code changes

for the gory details.

Adjust the patch accordingly and update all the relevant comments.

v3: Give up on the cargo-culting v2 attempt and just enfore the edp
bpp value if it's there. Broken panels be damned!

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This hack is getting a bit messy, but this plugs the leak for now
until we have the cpu_transcoder properly pipe_config'ed.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of repeatedly bombarding the user with a request to reboot and
increase the stolen size with every fb refresh, just inform them the
first time only.

v2: Rearrange code so the hint to increase the amount of memory stolen
by the BIOS is only emitted if we fail to find sufficient stolen memory
for FBC.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup formatting code mismatch that gcc spotted.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We prevent invalid ones from getting here in the first place, but it
doesn't hurt to have an extra sanity check.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
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>

This gets the panel fitter working on eDP on VLV, and should also apply
to eDP panels on G4x chipsets (if we ever detect and mark an all-in-one
panel as eDP anyway).

A few cleanups are still possible on top of this, for example the LVDS
border control could be placed in the LVDS encoder structure and updated
based on the result of the panel fitter calculation.

Multi-pipe fitting isn't handled correctly either if we ever get a config
that wants to try the panel fitter on more than one output at a time.

v2: use pipe_config for storing pfit values (Daniel)
    add i9xx_pfit_enable function for use by 9xx and VLV (Daniel)
v3: fixup conflicts and lvds_dither check
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: fix up botched conflict resolution from Jesse:
- border = LVDS_BORDER_ENABLE was lost for CENTER scaling
- comment about gen2/3 panel fitter scaling was lost
- dev_priv->lvds_dither reintroduced.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We only ever check whether it's strictly bigger than one, so all the
is_sdvo/is_hdmi checks are redundant. Flatten the code a bit.

Also, s/temp/dpll_md/
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we compute the pch pll state, we _have_ a pch encoder.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

g4x dplls and ilk+ pch plls have a separate field for the reduced p1
setting, so this restriction does not apply. Only older platforms have
the restriction that the p1 divisors must match.

This unnecessary restriction has been introduced in

commit cec2f356
Author: Sean Paul <seanpaul@chromium.org>
Date:   Tue Jan 10 15:09:36 2012 -0800

    drm/i915: Only look for matching clocks for LVDS downcloc

Note that with lvds the p2 divisors _always_ match for LVDS, and we
don't support auto-downclocking anywhere else. On eDP downclocking
works with separate data m/n settings, using the same link clock.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Up to now we've relied on the bios to get this right for us. Let's try
out whether our code has improved a bit, since we should dither
always when the output bpp doesn't match the plane bpp.
- gen5+ should be fine, since we only use the bios hint as an upgrade.
- gen4 changes, since here dithering is still controlled in the lvds
  register.
- gen2/3 has implicit dithering depeding upon whether you use 2 or 3
  lvds pairs (which makes sense, since it only supports 8bpc pipe
  outpu configurations).
- hsw doesn't support lvds.

v2: Remove redudant dither setting.

v3: Completly drop reliance on dev_priv->lvds_dither.

v4: Enable dithering on gen2/3 only when we have a 18bpp panel, since
up-dithering to a 24bpp panel is not supported by the hw. Spotted by
Ville.

v5: Also only enable lvds port dithering on gen4 for 18bpp modes. In
practice this only excludes dithering a 10bpc plane down for a 24bpp
lvds panel. Not something we truly care about. Again noticed by Ville.

v6: Actually git add.

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

With the exception of hsw, which has dedicated DP clocks which run at
the fixed frequency already, and vlv, which doesn't have optmized
pre-defined dp clock parameters (yet).

v2: Ville asked me to elaborate a bit more on the longer-term goals
wrt dpll settings computation:

So ultimately my idea is that in the compute config stage first the crtc
code puts the default platform pll limits into the pipe_config. Then
encoders can either overwrite that limit structure with their own special
stuff (mostly for lvds madness). Or they can pick some or all of the
parameters (e.g. just the p2 switchover on hdmi, or all the clock
parameters for dp/sdvo tv).

Once that's done then the generic crtc code can fill out any missing bits
(using the find_best_pll code) and then try to assign which pll to use (if
it's a platform with shared plls). In the end the modeset could should
simply write the computed stuff into registers and never be able to fail.

Of course there's still a lot of data to be moved into pipe_config to make
this all happen, hence some of the temporary ugliness.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was somehow lost in the pipe_config->dpll introduction in

commit f47709a9
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Mar 28 10:42:02 2013 +0100

    drm/i915: create pipe_config->dpll for clock state

While at it, extract a few small helpers for common computations.

v2: Use the newly added helpers more thanks to Ville's trick to
typedef the legacy intel_clock_t as the new-world struct dpll.

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

We need the dpll/fp/fp2 values only when we need a pch pll. So move
them together with the code to acquire such a pll.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Between ivb, hsw and vlv, only Ivybridge has sprites with scaling
capabilities.

Also make max_downscale coherent with that.

v2: Rebase on top of the recent ivb/vlv/hsw sprite scaling fixes.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> (v1)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>