Many GEN9 boards come with on-board lspcon cards.
Fot these boards, VBT configuration should properly point out
if a particular port contains lspcon device, so that driver can
initialize it properly.

This patch adds a utility function, which checks the VBT flag
for lspcon bit, and tells us if a port is configured to have a
lspcon device or not.

V2: Fixed review comments from Ville
- Do not forget PORT_D while checking lspcon for GEN9

V3: Addressed review comments from Rodrigo
- Create a HAS_LSPCON() macro for better use case handling.
- Do not dump warnings for non-gen-9 platforms, it will be noise.

V4: Rebase
V5: Rebase
V6: Pass dev_priv to HAS_LSPCON() macro
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476455212-27893-4-git-send-email-shashank.sharma@intel.com

Leave behind some debugging clues in case some panels don't work
properly.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/b36302b24676af511f4bbf702be21cc7e8f987c2.1474286487.git.jani.nikula@intel.com

Since drm_i915_private is now a subclass of drm_device we do not need to
chase the drm_i915_private->dev backpointer and can instead simply
access drm_i915_private->drm directly.

   text	   data	    bss	    dec	    hex	filename
1068757	   4565	    416	1073738	 10624a	drivers/gpu/drm/i915/i915.ko
1066949	   4565	    416	1071930	 105b3a	drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:
@@
struct drm_i915_private *d;
identifier i;
@@
(
- d->dev->i
+ d->drm.i
|
- d->dev
+ &d->drm
)

and for good measure the dev_priv->dev backpointer was removed entirely.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467711623-2905-4-git-send-email-chris@chris-wilson.co.uk

The VBT has these mysterious H/V image sizes as part of the display
timings. Looking at some dumps those appear to be the physical
dimensions in mm. Which makes sense since the timing descriptor matches
the format used by EDID detailed timing descriptor, which defines these
as "H/V Addressable Video Image Size in mm".

So let's use that information from the panel fixed mode to get the
physical dimensions for LVDS/eDP/DSI displays. And with that we can
fill out the display_info so that userspace can get at it via
GetConnector.

v2: Use (hi<<8)|lo instead of broken (hi<<4)+lo
    Handle LVDS and eDP too

Cc: Stephen Just <stephenjust@gmail.com>
Tested-by: NStephen Just <stephenjust@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96255Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464685714-30507-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NMika Kahola <mika.kahola@intel.com>
(cherry picked from commit df457245)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Apparently some CHV boards failed to hook up the port presence straps
for HDMI ports as well (earlier we assumed this problem only affected
eDP ports). So let's check the VBT in addition to the strap, and if
either one claims that the port is present go ahead and register the
relevant connector.

While at it, change port D to register DP before HDMI as we do for ports
B and C since
commit 457c52d8 ("drm/i915: Only ignore eDP ports that are connected")

Also print a debug message when we register a HDMI connector to aid
in diagnosing missing/incorrect ports. We already had such a print for
DP/eDP.

v2: Improve the comment in the code a bit, note the port D change in
    the commit message

Cc: Radoslav Duda <radosd@radosd.com>
Tested-by: NRadoslav Duda <radosd@radosd.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96321Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464945463-14364-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 22f35042)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

My old 845g complains that the child_device_size inside its VBT,
version 110, is incorrect. Let's fiddle with the version matching such
that it works with this VBT (i.e. treat BIOS v110 as having the same size
as v108).

Fixes [drm:intel_bios_init] *ERROR* Unexpected child device config
size 27 (expected 33 for VBT version 110)

Whether this is correct, no one knows - but it works for this particular
machine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464800923-6054-1-git-send-email-chris@chris-wilson.co.uk
(cherry picked from commit fa05178c)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Apparently some CHV boards failed to hook up the port presence straps
for HDMI ports as well (earlier we assumed this problem only affected
eDP ports). So let's check the VBT in addition to the strap, and if
either one claims that the port is present go ahead and register the
relevant connector.

While at it, change port D to register DP before HDMI as we do for ports
B and C since
commit 457c52d8 ("drm/i915: Only ignore eDP ports that are connected")

Also print a debug message when we register a HDMI connector to aid
in diagnosing missing/incorrect ports. We already had such a print for
DP/eDP.

v2: Improve the comment in the code a bit, note the port D change in
    the commit message

Cc: Radoslav Duda <radosd@radosd.com>
Tested-by: NRadoslav Duda <radosd@radosd.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96321Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464945463-14364-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

The VBT has these mysterious H/V image sizes as part of the display
timings. Looking at some dumps those appear to be the physical
dimensions in mm. Which makes sense since the timing descriptor matches
the format used by EDID detailed timing descriptor, which defines these
as "H/V Addressable Video Image Size in mm".

So let's use that information from the panel fixed mode to get the
physical dimensions for LVDS/eDP/DSI displays. And with that we can
fill out the display_info so that userspace can get at it via
GetConnector.

v2: Use (hi<<8)|lo instead of broken (hi<<4)+lo
    Handle LVDS and eDP too

Cc: Stephen Just <stephenjust@gmail.com>
Tested-by: NStephen Just <stephenjust@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96255Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464685714-30507-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NMika Kahola <mika.kahola@intel.com>

My old 845g complains that the child_device_size inside its VBT,
version 110, is incorrect. Let's fiddle with the version matching such
that it works with this VBT (i.e. treat BIOS v110 as having the same size
as v108).

Fixes [drm:intel_bios_init] *ERROR* Unexpected child device config
size 27 (expected 33 for VBT version 110)

Whether this is correct, no one knows - but it works for this particular
machine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464800923-6054-1-git-send-email-chris@chris-wilson.co.uk

Prefer passing struct drm_i915_private to internal interfaces as this
saves us having to dance between drm_device and our native struct. The
savings hare are small (only 70 bytes of unrequired dancing), but
progressive!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464012490-30961-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJani Nikula <jani.nikula@linux.intel.com>

DP dual mode type 1 DVI adaptors aren't required to implement any
registers, so it's a bit hard to detect them. The best way would
be to check the state of the CONFIG1 pin, but we have no way to
do that. So as a last resort, check the VBT to see if the HDMI
port is in fact a dual mode capable DP port.

v2: Deal with VBT code reorganization
    Deal with DRM_DP_DUAL_MODE_UNKNOWN
    Reduce DEVICE_TYPE_DP_DUAL_MODE_BITS a bit
    Accept both DP and HDMI dvo_port in VBT as my BSW
    at least declare its DP port as HDMI :(
v3: Ignore DEVICE_TYPE_NOT_HDMI_OUTPUT (Shashank)

Cc: stable@vger.kernel.org
Cc: Tore Anderson <tore@fud.no>
Reported-by: NTore Anderson <tore@fud.no>
Fixes: 7a0baa62 ("Revert "drm/i915: Disable 12bpc hdmi for now"")
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462362322-31278-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NShashank Sharma <shashank.sharma@intel.com>
(cherry picked from commit d6199256)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

DP dual mode type 1 DVI adaptors aren't required to implement any
registers, so it's a bit hard to detect them. The best way would
be to check the state of the CONFIG1 pin, but we have no way to
do that. So as a last resort, check the VBT to see if the HDMI
port is in fact a dual mode capable DP port.

v2: Deal with VBT code reorganization
    Deal with DRM_DP_DUAL_MODE_UNKNOWN
    Reduce DEVICE_TYPE_DP_DUAL_MODE_BITS a bit
    Accept both DP and HDMI dvo_port in VBT as my BSW
    at least declare its DP port as HDMI :(
v3: Ignore DEVICE_TYPE_NOT_HDMI_OUTPUT (Shashank)

Cc: stable@vger.kernel.org
Cc: Tore Anderson <tore@fud.no>
Reported-by: NTore Anderson <tore@fud.no>
Fixes: 7a0baa62 ("Revert "drm/i915: Disable 12bpc hdmi for now"")
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462362322-31278-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NShashank Sharma <shashank.sharma@intel.com>

These fields in VBT indicates the PWM source which
is used and also the controller number.

v2 by Jani: check for out of bounds access, some renames, change default
type, etc.

v3 by Jani: s/INTEL_BACKLIGHT_CABC/INTEL_BACKLIGHT_DSI_DCS/
Signed-off-by: NDeepak M <m.deepak@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/eee2f7b683a081f006a7df1ddad9b20fbf53c48c.1461676337.git.jani.nikula@intel.com

For dual link panel scenarios there are new fields added in the
VBT which indicate on which port the PWM cntrl and CABC ON/OFF
commands needs to be sent.

v2: Moving the comment to intel_dsi.h(Jani)

v3: Renaming the field names (Jani)

v4 by Jani: make this patch only about VBT

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Yetunde Adebisi <yetundex.adebisi@intel.com>
Signed-off-by: NDeepak M <m.deepak@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459346623-30752-2-git-send-email-jani.nikula@intel.com

We've had problems on several occasions with using the panel type
from the VBT block 40. Usually it seems to be 2, which often
doesn't give us the correct timings for the panel. After some
more digging I found a way to get a panel type via the OpRegion
SWSCI GBDA "Get Panel Details" method. Let's try to use it.

The spec has this to say about the output:
"Bits [15:8] - Panel Type
 Bits contain the panel type user setting from CMOS
 00h = Not Valid, use default Panel Type & Timings from VBT
 01h - 0Fh = Panel Number"

Another version of the spec lists the valid range as 1-16, which makes
more sense since VBT supports 16 panels. Based on actual results
from Rob's G45, 1-16 is what we need to accept.

The other bits in the output don't look relevant for the problem at
hand.

The input is specified as:
"Bits [31:4] - Reserved
 Reserved (must be zero)
 Bits [3:0] - Panel Number
 These bits contain the sequential index of Panel, starting at 0 and
 counting upwards from the first integrated Internal Flat-Panel Display
 Encoder present, and then from the first external Display Encoder
 (e.g., S/DVO-B then S/DVO-C) which supports Internal Flat-Panels.
 0h - 0Fh = Panel number"

For now I've just hardcoded the input panel number as 0. That would seem
like a decent choise for LVDS. Not so sure about eDP when port != A.

v2: Accept values 1-16
    Filter out bogus results in opregion code (Jani)
    Add debug logging for all the different branches (Jani)

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rob Kramer <rob@solution-space.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94825Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460359431-11003-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: NRob Kramer <rob@solution-space.com>

Store the extracted panel_type under dev_priv.vbt instead of keeping
around a static variable for it.

Cc: Rob Kramer <rob@solution-space.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>

VBT can only contain 16 panel entries, indexed with the panel_type.
To play it safe we should reject panel_type > 0xf, so that we don't
read past the valid data.

v2: Add debug logging (Jani)

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rob Kramer <rob@solution-space.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1460359329-10817-1-git-send-email-ville.syrjala@linux.intel.com

This patch sets the invert bit for hpd detection for each port
based on VBT configuration. Since each AOB can be designed to
depend on invert bit or not, it is expected if an AOB requires
invert bit, the user will set respective bit in VBT.

v2: Separated VBT parsing from the rest of the logic. (Jani)

v3: Moved setting invert bit logic to bxt_hpd_irq_setup()
    and changed its logic to avoid looping twice. (Ville)

v4: Changed the logic to mask out the bits first and then
    set them to remove need of temporary variable. (Ville)

v5: Moved defines to existing set of defines for the register
    and added required breaks. (Ville)
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[Jani: fixed some checkpatch noise, added kernel-doc.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459420907-11383-2-git-send-email-shubhangi.shrivastava@intel.com

This patch adds new fields that are not yet added in drm code
in child devices struct
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459420907-11383-1-git-send-email-shubhangi.shrivastava@intel.com

Set from VBT, but never used. Good riddance.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-5-git-send-email-jani.nikula@intel.com

Move all data initialized from VBT under dev_priv->vbt. No functional
changes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-4-git-send-email-jani.nikula@intel.com

Move all data initialized from VBT under dev_priv->vbt. No functional
changes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-3-git-send-email-jani.nikula@intel.com

Housekeeping, similar to psr, backlight, and dsi. No functional changes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458834623-8734-2-git-send-email-jani.nikula@intel.com

We've been accumulating code across the driver that depends on the VBT
specific structures and defines. The VBT is an uncontrollable
beast. Encourage encapsulation of the VBT data by hiding the structures
and defines in a private header only to be included from intel_bios.c.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-7-git-send-email-jani.nikula@intel.com

Favor a single point of truth instead of duplicating the
information. The change also filters out unsupported DSI ports at this
stage, accepting only ports A and C, instead of waiting until the port
checks.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-6-git-send-email-jani.nikula@intel.com

Hide knowledge about VBT child devices in intel_bios.c.

v2: Move port check to intel_bios.c (Sivakumar)
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-4-git-send-email-jani.nikula@intel.com

Hide knowledge about VBT child devices in intel_bios.c.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-3-git-send-email-jani.nikula@intel.com

Hide knowledge about VBT child devices in intel_bios.c.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-2-git-send-email-jani.nikula@intel.com

Hide knowledge about VBT child devices in intel_bios.c.

v2: also move int_tv_support check to intel_bios.c (Sivakumar)
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125015-7931-1-git-send-email-jani.nikula@intel.com

Two errors in a single line. The size was read from the wrong offset,
and the end index didn't take the five bytes for sequence byte and size
of sequence into account. Fix it all, and break up the calculations a
bit to make it clearer.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reported-and-tested-by: NMika Kahola <mika.kahola@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Fixes: 2a33d934 ("drm/i915/bios: add support for MIPI sequence block v3")
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452784327-27258-1-git-send-email-jani.nikula@intel.com

My 830 has VBT version 105 with child device size of 22 bytes.
Let's assume that's correct and adjust our expectations.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450110229-30450-9-git-send-email-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>

My 85x has VBT version 108 which has a child dev size of 27 bytes.
Let's allow that without printing an error.

We still want to reject the actual parsin since for that we need
the child device size to be at least 33 bytes. So we should still
check for that, but let's make it print a debug message only instead
of an error.

While at it, toss in a BUILD_BUG_ON() to verify our struct
old_child_dev_config is in fact 33 bytes.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450110229-30450-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

The changes since the sequence block v2 are:

* The whole MIPI bios data block has a separate 32-bit size field since
  v3, stored after the version. This facilitates big sequences.

* The size of the panel specific sequence blocks has grown to 32
  bits. This facilitates big sequences.

* The elements within sequences now have an 8-bit size field following
  the operation byte. This facilitates skipping unknown new operation
  bytes, i.e. forward compatibility.

v2 (of the patch): use DRM_ERROR for unknown operation byte
v3 (of the patch): even more bounds checking (Ville)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452518102-3154-1-git-send-email-jani.nikula@intel.com

Add parsing of the i2c element, defined in MIPI sequence block v2. Drop
the status operation byte while at it, that does not exist.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/d8a2998977feee2f5b5ad609aaca787adfb41479.1450702954.git.jani.nikula@intel.com

Make everything a bit more readable and clear.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e8f2a62d78d90981a6b49fdf9ab3594f60a46033.1450702954.git.jani.nikula@intel.com

Make the whole thing easier to read. While at it, make the parsing more
robust, and ensure we don't read past buffer being parsed.

v2: improve commit message (Daniel)
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452001851-8967-1-git-send-email-jani.nikula@intel.com

Have get_blocksize() support the special case of MIPI sequence block v3+
which has a separate field for size. Provide and use abstractions for
getting the blocksize given a pointer to the block "envelope",
i.e. pointer to the block id, and given a pointer to the block payload
data.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e935bd5e119a83dd91214c47e6cd4f6ce8b2a17e.1450702954.git.jani.nikula@intel.com

There's two blocks to parse, have one function per block. The existing
one cuts neatly into two.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/6c9598e2b4d07e8d264617cdfe8b6527a74261f7.1450702954.git.jani.nikula@intel.com

Add an overview and documentation for the VBT/BDB header structures.
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/3d826d4600688ca3518713776ab5bd8a8fc9f20f.1450702954.git.jani.nikula@intel.com

Slightly cleaner with early exit.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450271061-32646-4-git-send-email-jani.nikula@intel.com