This reverts commit 5d250b05.

It results on a deadlock on platforms where we need to (at least
partially) re-init hpd interrupts from power domain code, since
->hot_plug might again grab a power well reference (to do edid/dp_aux
transactions. At least chv is affected.
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
References: http://mid.gmane.org/20151008133548.GX26517@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This reverts commit 0b5e88dc.

It completely breaks booting on at least bsw (and maybe more).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88081Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Use goto to handle the error path to avoid duplicating the same code. In
the error path intel_dig_port is the last one to be released as it was
the first one to be allocated and ideally the error path should be the
reverse of the execution path.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is a typo in the function i915_handle_error()
kernel-doc and the word register is spelled wrongly.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add the dev parameter for the functions i915_enable_asle_pipestat() and
i915_reset_and_wakeup() to the kernel-doc to fix the following warnings:

.//drivers/gpu/drm/i915/i915_irq.c:586: warning: No description found for parameter 'dev'
.//drivers/gpu/drm/i915/i915_irq.c:2400: warning: No description found for parameter 'dev'
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_rcs_ctx_init() emits all workaround register writes on the list
to the ring, in addition to calling i915_gem_render_state_init().  The
workaround list is currently empty on Gen6-7 so this shouldn't cause
any functional changes.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's not an error for the workaround list to be empty if no
workarounds are needed.  This will avoid spamming the logs
unnecessarily on Gen6 after the workaround list is hooked up on
pre-Gen8 hardware by the following commits.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In

commit 8f0e2b9d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Dec 2 16:19:07 2014 +0100

    drm/i915: Move golden context init into ->init_context

I've shuffled around per-ctx init code a bit for legacy contexts but
accidentally dropped the render state init call on gen6/7. Resurrect
it.
Reported-by: NFrancisco Jerez <currojerez@riseup.net>
Cc: Francisco Jerez <currojerez@riseup.net>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Thomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Appease gcc and remove the unused variable.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Note that in Bspec you have to dig around in a section called
"Timestamp bases" and Bspec update request is filed.
Signed-off-by: NAnkitprasad Sharma <ankitprasad.r.sharma@intel.com>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
[danvet: Add note about state of Bspec.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Passing cliprects into the kernel for it to re-execute the batch buffer
with different CMD_DRAWRECT died out long ago. As DRI1 support has been
removed from the kernel, we can now simply reject any execbuf trying to
use this "feature".

To keep Daniel happy with the prospect of being able to reuse these
fields in the next decade, continue to ensure that current userspace is
not passing garbage in through the dead fields.

v2: Fix the cliprects_ptr check
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Exclude active GPU pages from the purview of the background shrinker
(kswapd), as these cause uncontrollable GPU stalls. Given that the
shrinker is rerun until the freelists are satisfied, we should have
opportunity in subsequent passes to recover the pages once idle. If the
machine does run out of memory entirely, we have the forced idling in the
oom-notifier as a means of releasing all the pages we can before an oom
is prematurely executed.

Note that this relies upon an up-front retire_requests to keep the
inactive list in shape, which was added in a previous patch, mostly as
execlist ctx pinning band-aids.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Add note about retire_requests.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With UMS gone, we no longer use it during suspend. And with the last
user removed from the shrinker, we can remove the dead code.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We can forgo an evict-everything here as the shrinker operation itself
will unbind any vma as required. If we explicitly idle the GPU through a
switch to the default context, we not only create a request in an
illegal context (e.g. whilst shrinking during execbuf with a request
already allocated), but switching to the default context will not free
up the memory backing the active contexts - unless in the unlikely
situation that context had already been closed (and just kept arrive by
being the current context). The saving is near zero and the danger real.

To compensate for the loss of the forced retire, add a couple of
retire-requests to i915_gem_shirnk() - this should help free up any
transitive cache from the requests.

Note that the second retire_requests is for the benefit of the
hand-rolled execlist ctx active tracking: We need to manually kick
requests to get those unpinned again. Once that's fixed we can try to
remove this again.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add summary of why we need a pile of retire_requests.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Often it is very useful to know why we suddenly purge vast tracts of
memory and surprisingly up until now we didn't even have a tracepoint
for when we shrink our memory.

Note that there are slab_start/end tracepoints already, but those
don't cover the internal recursion when we directly call into our
shrinker code. Hence a separate tracepoint seems justified. Also note
that we don't really need a separate tracepoint for the actual amount
of pages freed since we already have an unbind tracpoint for that.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add a note that there's also slab_start/end and why they're
insufficient.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add the item of i915_component.h in DocBook and add the DOC for
i915_component.h. Explain the struct i915_audio_component_ops and
struct i915_audio_component_audio_ops usage.
Signed-off-by: NLibin Yang <libin.yang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add the kerneldoc for i915_audio_component in i915_component.h
Signed-off-by: NLibin Yang <libin.yang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull in the i915/hda changes for N/CTS setting so I can apply the
follow-up documentation work for drm/i915.

Some conflicts because ofc we had to rework i915 while that N/CTS work
was going on. But not more than adjacent changes really.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

As the shrinker_control now passes us unsigned long targets, update our
shrinker functions to match.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've botched this, so let's fix it.

Botched in

commit eb0b44ad
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 18 14:47:59 2015 +0100

    drm/i915: kerneldoc for i915_gem_shrinker.c

v2: Be a good citizen^Wmaintainer and add the proper commit citation.
Noticed by Jani.
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Whilst discussing possible ways to trigger an invalidate_range on a
userptr with an aliased GGTT mmapping (and so cause a struct_mutex
deadlock), the conclusion is that we can, and we must, prevent any
possible deadlock by avoiding taking the mutex at all during
invalidate_range. This has numerous advantages all of which stem from
avoid the sleeping function from inside the unknown context. In
particular, it simplifies the invalidate_range because we no longer
have to juggle the spinlock/mutex and can just hold the spinlock
for the entire walk. To compensate, we have to make get_pages a bit more
complicated in order to serialise with a pending cancel_userptr worker.
As we hold the struct_mutex, we have no choice but to return EAGAIN and
hope that the worker is then flushed before we retry after reacquiring
the struct_mutex.

The important caveat is that the invalidate_range itself is no longer
synchronous. There exists a small but definite period in time in which
the old PTE's page remain accessible via the GPU. Note however that the
physical pages themselves are not invalidated by the mmu_notifier, just
the CPU view of the address space. The impact should be limited to a
delay in pages being flushed, rather than a possibility of writing to
the wrong pages. The only race condition that this worsens is remapping
an userptr active on the GPU where fresh work may still reference the
old pages due to struct_mutex contention. Given that userspace is racing
with the GPU, it is fair to say that the results are undefined.

v2: Only queue (and importantly only take one refcnt) the worker once.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Michał Winiarski found a really evil way to trigger a struct_mutex
deadlock with userptr. He found that if he allocated a userptr bo and
then GTT mmaped another bo, or even itself, at the same address as the
userptr using MAP_FIXED, he could then cause a deadlock any time we then
had to invalidate the GTT mmappings (so at will). Tvrtko then found by
repeatedly allocating GTT mmappings he could alias with an old userptr
mmap and also trigger the deadlock.

To counter act the deadlock, we make the observation that we only need
to take the struct_mutex if the object has any pages to revoke, and that
before userspace can alias with the userptr address space, it must have
invalidated the userptr->pages. Thus if we can check for those pages
outside of the struct_mutex, we can avoid the deadlock. To do so we
introduce a separate flag for userptr objects that we can inspect from
the mmu-notifier underneath its spinlock.

The patch makes one eye-catching change. That is the removal serial=0
after detecting a to-be-freed object inside the invalidate walker. I
felt setting serial=0 was a questionable pessimisation: it denies us the
chance to reuse the current iterator for the next loop (before it is
freed) and being explicit makes the reader question the validity of the
locking (since the object-free race could occur elsewhere). The
serialisation of the iterator is through the spinlock, if the object is
freed before the next loop then the notifier.serial will be incremented
and we start the walk from the beginning as we detect the invalid cache.

To try and tame the error paths and interactions with the userptr->active
flag, we have to do a fair amount of rearranging of get_pages_userptr().

v2: Grammar fixes
v3: Reorder set-active so that it is only set when obj->pages is set
(and so needs cancellation). Only the order of setting obj->pages and
the active-flag is crucial. Calling gup after invalidate-range begin
means the userptr sees the new set of backing storage (and so will not
need to invalidate its new pages), but we have to be careful not to set
the active-flag prior to successfully establishing obj->pages.
v4: Take the active->flag early so we know in the mmu-notifier when we
have to cancel a pending gup-worker.
v5: Rearrange the error path so that is not so convoluted
v6: Set pinned to 0 when negative before calling release_pages()
Reported-by: NMichał Winiarski <michal.winiarski@intel.com>
Testcase: igt/gem_userptr_blits/map-fixed*
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The userptr worker allows for a slight race condition where upon there
may two or more threads calling get_user_pages for the same object. When
we have the array of pages, then we serialise the update of the object.
However, the worker should only overwrite the obj->userptr.work pointer
if and only if it is the active one. Currently we clear it for a
secondary worker with the effect that we may rarely force a second
lookup.

v2: Rebase and rename a variable to avoid 80cols
v3: Mention v2
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We tried to fix this in commit fdc454c1 ("drm/i915: Prevent out of
range pt in gen6_for_each_pde").

But the static analyzer still complains that, just before we break due
to "iter < I915_PDES", we do "pt = (pd)->page_table[iter]" with an
iter value that is bigger than I915_PDES. Of course, this isn't really
a problem since no one uses pt outside the macro. Still, every single
new usage of the macro will create a new issue for us to mark as a
false positive.

Also, Paulo re-started the discussion a while ago [1], but didn't end up
implemented.

In order to "solve" this "problem", this patch takes the ideas from
Chris and Dave, but that check would change the desired behavior of the
code, because the object (for example pdp->page_directory[iter]) can be
null during init/alloc, and C would take this as false, breaking the for
loop immediately.

This has been already verified with "static analysis tools".

[1]http://lists.freedesktop.org/archives/intel-gfx/2015-June/068548.html

v2: Make it a single statement, while preventing the common subexpression
elimination (Chris)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Prevent leaking VMAs and PPGTT VMs when objects are imported
via flink.

Scenario is that any VMAs created by the importer will be left
dangling after the importer exits, or destroys the PPGTT context
with which they are associated.

This is caused by object destruction not running when the
importer closes the buffer object handle due the reference held
by the exporter. This also leaks the VM since the VMA has a
reference on it.

In practice these leaks can be observed by stopping and starting
the X server on a kernel with fbcon compiled in. Every time
X server exits another VMA will be leaked against the fbcon's
frame buffer object.

Also on systems where flink buffer sharing is used extensively,
like Android, this leak has even more serious consequences.

This version is takes a general approach from the  earlier work
by Rafael Barbalho (drm/i915: Clean-up PPGTT on context
destruction) and tries to incorporate the subsequent discussion
between Chris Wilson and Daniel Vetter.

v2:

Removed immediate cleanup on object retire - it was causing a
recursive VMA unbind via i915_gem_object_wait_rendering. And
it is in fact not even needed since by definition context
cleanup worker runs only after the last context reference has
been dropped, hence all VMAs against the VM belonging to the
context are already on the inactive list.

v3:

Previous version could deadlock since VMA unbind waits on any
rendering on an object to complete. Objects can be busy in a
different VM which would mean that the cleanup loop would do
the wait with the struct mutex held.

This is an even simpler approach where we just unbind VMAs
without waiting since we know all VMAs belonging to this VM
are idle, and there is nothing in flight, at the point
context destructor runs.

v4:

Double underscore prefix for __915_vma_unbind_no_wait and a
commit message typo fix. (Michel Thierry)

Note that this is just a partial/interim fix since we have a bit a
fundamental issue with cleaning up, e.g.

https://bugs.freedesktop.org/show_bug.cgi?id=87729Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Testcase: igt/gem_ppgtt.c/flink-and-exit-vma-leak
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rafael Barbalho <rafael.barbalho@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
[danvet: Add a note that this isn't everything.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The link training functions had confusing names. The start function
actually does the clock recovery phase of the link training, and the
complete function does the channel equalization. So call them that
instead. Also, every call to intel_dp_start_link_train() was followed
by a call to intel_dp_complete_link_train(), so add a new start
function that calls clock_recory and channel_equalization.
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds a separate probe function for HDMI
EDID read over DDC channel. This function has been
registered as a .hot_plug handler for HDMI encoder.

The current implementation of hdmi_detect()
function re-sets the cached HDMI edid (in connector->detect_edid) in
every detect call.This function gets called many times, sometimes
directly from userspace probes, forcing drivers to read EDID every
detect function call.This causes several problems like:

1. Race conditions in multiple hot_plug / unplug cases, between
   interrupts bottom halves and userspace detections.
2. Many Un-necessary EDID reads for single hotplug/unplug
3. HDMI complaince failures which expects only one EDID read per hotplug

This function will be serving the purpose of really reading the EDID
by really probing the DDC channel, and updating the cached EDID.

The plan is to:
1. i915 IRQ handler bottom half function already calls
   intel_encoder->hotplug() function. Adding This probe function which
   will read the EDID only in case of a hotplug / unplug.
2. During init_connector this probe will be called to read the edid
3. Reuse the cached EDID in hdmi_detect() function.

The "< gen7" check is there because this was tested only for >=gen7
platforms. For older platforms the hotplug/reading edid path remains same.

v2: Calling set_edid instead of hdmi_probe during init.
Also, for platforms having DDI, intel_encoder for DP and HDMI is same
(taken from intel_dig_port), so for DP also, hot_plug function gets called
which is not intended here. So, check for HDMI in intel_hdmi_probe
Rely on HPD for updating edid only for platforms gen > 8 and also for VLV.

v3: Dropping the gen < 8 || !VLV  check. Now all platforms should rely on
hotplug or init for updating the edid.(Daniel)
Also, calling hdmi_probe in init instead of set_edid

v4: Renaming intel_hdmi_probe to intel_hdmi_hot_plug.
Also calling this hotplug handler from intel_hpd_init to take care of init
resume scenarios.

v5: Moved the call to encoder hotplug during init to separate patch(Daniel)
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
[danvet: Mark intel_hdmi_hot_plug as static.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is required to support glDispatchComputeIndirect for gen7.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NKristian Høgsberg <krh@bitplanet.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When using RC6 timeout mode, the timeout value
should be written to GEN6_RC6_THRESHOLD.

v2: Updated commit message. (Tom)

v3: Rebase over whitespace differences. (Daniel)

Cc: Tom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add host2guc interface to notify GuC power state changes when
enter or resume from power saving state.

v3: Move intel_guc_suspend to i915_drm_suspend for consistency.

v2: Add GuC suspend/resume to runtime suspend/resume too

v1: Change to a more flexible way when fill host to GuC scratch
data in order to remove hard coding.
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The BIOS can leave the CHV display PHY in some odd state where
some of the LDOs/lanes won't power down fully when unused. This
will trigger a host of asserts that were added in:
30142273 drm/i915: Add CHV PHY LDO power sanity checks
6669e39f drm/i915: Add some CHV DPIO lane power state asserts

To avoid that, skip the asserts until the PHY power well has been
disabled at least once. That will fully reset the PHY, and once
brought back up, the dynamic power down features will work correctly.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The docs are unclear as usual, so it's not clear whether LRC should be
bypassed, performed normally or GRC code should be used as the LRC code.
Some old docs stated that LRC bypass ought to be used, more recent ones
no longer say that. Some docs indicated that we could use GRC as the LRC
code on CHV, but the BIOS doesn't do that, so let's not do it either.

Besides to enable LRC bypass properly, I believe we should set the bit
already before deasserting cmnreset.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For all the encoders, call the hot_plug if it is registered.
This is required for connected boot and resume cases to generate
fake hpd resulting in reading of edid.
Removing the initial sdvo hot_plug call too so that it will be called
just once from this loop.
Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to call intel_runtime_pm_put() and mutex_unlock() before
returning.

Fixes: 7cb5dff8 ('drm/i915: fix task reference leak in i915_debugfs.c')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Latest VBT mentions which set of registers will be used for BLC,
as controller number field. Making use of this field in BXT
BLC implementation. Also, the registers are used in case control
pin indicates display DDI. Adding a check for this.
According to Bspec, BLC_PWM_*_2 uses the display utility pin for output.
To use backlight 2, enable the utility pin with mode = PWM
   v2: Jani's review comments
   addressed
       - Add a prefix _ to BXT BLC registers definitions.
       - Add "bxt only" comment for u8 controller
       - Remove control_pin check for DDI controller
       - Check for valid controller values
       - Set pipe bits in UTIL_PIN_CTL
       - Enable/Disable UTIL_PIN_CTL in enable/disable_backlight()
       - If BLC 2 is used, read active_low_pwm from UTIL_PIN polarity
   Satheesh's review comment addressed
       - If UTIL PIN is already enabled, BIOS would have programmed it. No
       need to disable and enable again.
   v3: Jani's review comments
       - add UTIL_PIN_PIPE_MASK and UTIL_PIN_MODE_MASK
       - Disable UTIL_PIN if controller 1 is used
       - Mask out UTIL_PIN_PIPE_MASK and UTIL_PIN_MODE_MASK before enabling
       UTIL_PIN
       - check valid controller value in intel_bios.c
       - add backlight.util_pin_active_low
       - disable util pin before enabling
   v4: Change for BXT-PO branch:
   Stubbed unwanted definition which was existing before
   because of DC6 patch.
   UTIL_PIN_MODE_PWM     (0x1b << 24)

v2: Fixed Jani's review comment.

v3: Split the backight PWM frequency programming into separate patch,
    in cases BIOS doesn't initializes it.

v4: Starting afresh and not modifying existing state for backlight, as
    per Jani's recommendation.

v5: Fixed Jani's review comment wrt util pin enable
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Signed-off-by: NSunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BXT's DSI PLL is different from that of VLV. So this patch
adds a new function to get the current DSI pixel clock based
on the PLL divider ratio and lane count.

This function is required for intel_dsi_get_config() function.

v2: Fixed Jani's review comments.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pick appropriate port control register (BXT or VLV), based on device.
Get the current hw state wrt Mipi port.

v2: Rebased on latest drm nightly branch.

v3: Removed the GET_DSI_PORT_CTRL Macro for consistency with earlier
    implementations as per Jani's suggestion.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch contains changes to support DSI disble sequence in BXT.
The changes are:
1. BXT specific changes in clear_device_ready function.
2. BXT specific changes in DSI disable and post-disable functions.
3. Add a new function to reset BXT Dphy clock and dividers
   (bxt_dsi_reset_clocks).
4. Moved some part of the vlv clock reset code, in a new function
   (vlv_dsi_reset_clocks) maintaining the exact same sequence.
5. Wrapper function to call corresponding reset clock function.

v2: Fixed Jani's review comments.

v3: Removed the GET_DSI_PORT_CTRL Macro for consistency with earlier
    implementations as per Jani's suggestion.
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>