drm/displayid: provide access to DisplayID version and primary use case

The DisplayID structure version and primary use case are stored in the
DisplayID Base Section. We should be checking them in a number of places
when parsing the DisplayID blocks. Currently, we completely ignore the
primary use case, and just look at the block tags without cross-checking
against structure version.

Store the version and primary use case in the DisplayID iterator, and
provide accessors to them. In general, the information is needed when
iterating the blocks, and this is a convenient place to both store and
retrieve the information during parsing.

Promote using accessors rather than users poking at the iterator
directly.

Cc: Iaroslav Boliukin <iam@lach.pw>
Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ad8a35c109f97ffe115e6b18e4a132b592f11089.1676580180.git.jani.nikula@intel.com

drm/displayid: convert to drm_edid

We'll need to propagate drm_edid everywhere.

v2: Rebase

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a52a6882e87a4bb6b1670918f3aba13f9b52f6de.1652097712.git.jani.nikula@intel.com

drm/edid: parse the DisplayID v2.0 VESA vendor block for MSO

The VESA Organization Vendor-Specific Data Block, defined in VESA
DisplayID Standard v2.0, specifies the eDP Multi-SST Operation (MSO)
stream count and segment pixel overlap.

DisplayID v1.3 has Appendix B: DisplayID as an EDID Extension,
describing how DisplayID sections may be embedded in EDID extension
blocks. DisplayID v2.0 does not have such a section, perhaps implying
that DisplayID v2.0 data should not be included in EDID extensions, but
rather in a "pure" DisplayID structure at its own DDC address pair
A4h/A5h, as described in VESA E-DDC Standard v1.3 chapter 3.

However, in practice, displays out in the field have embedded DisplayID
v2.0 data blocks in EDID extensions, including, in particular, some eDP
MSO displays, where a pure DisplayID structure is not available at all.

Parse the MSO data from the DisplayID data block. Do it as part of
drm_add_display_info(), extending it to parse also DisplayID data to
avoid requiring extra calls to update the information.

v2: Check for VESA OUI (Ville)

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/73ca2887e7b37880690f5c9ba4594c9cd1170669.1630419362.git.jani.nikula@intel.com

drm/displayid: add DisplayID v2.0 data blocks and primary use cases

DisplayID v2.0 changes the data block identifiers and product types (now
called primary use cases).

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/5a5c7e4477782c174f494947e2a2ea618b2b1ef2.1630419362.git.jani.nikula@intel.com

drm/displayid: re-align data block macros

Make the values easier to read. Also add DisplayID Structure version and
revision information (this is different from the spec version).

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b73d3ff2d5e4b23834ed0005186c5cf3a9de5c9e.1630419362.git.jani.nikula@intel.com

drm/displayid: rename displayid_hdr to displayid_header

Avoid any confusion with High Dynamic Range. No functional changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ce083bd2789c7e22a91710726162287db88e3f6c.1617024940.git.jani.nikula@intel.com

drm/edid: use the new displayid iterator for tile info

Neatly reduce displayid boilerplate in code. Remove excessive debug
logging while at it, no other functional changes.

The old displayid iterator becomes unused; remove it as well as make
drm_find_displayid_extension() static.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fa4b5c790b5bdd82063545a6f209f8e9d78a63a7.1617024940.git.jani.nikula@intel.com

drm/displayid: add new displayid section/block iterators

Iterating DisplayID blocks across sections (in EDID extensions) is
unnecessarily complicated for the caller. Implement DisplayID iterators
to go through all blocks in all sections.

Usage example:

const struct displayid_block *block;
struct displayid_iter iter;

displayid_iter_edid_begin(edid, &iter);
displayid_iter_for_each(block, &iter) {
/* operate on block */
}
displayid_iter_end(&iter);

When DisplayID is stored in EDID extensions, the DisplayID sections map
to extensions as described in VESA DisplayID v1.3 Appendix B: DisplayID
as an EDID Extension. This is implemented here.

When DisplayID is stored in its dedicated DDC device 0xA4, according to
VESA E-DDC v1.3, different rules apply for the structure. This is not
implemented here, as we don't currently use it, but the idea is you'd
have a different call for beginning the iteration, for example simply:

displayid_iter_begin(displayid, &iter);

instead of displayid_iter_edid_begin(), and everything else would be
hidden away in the iterator functions.

v2:
- sizeof(struct displayid_block) -> sizeof(*block) (Ville)
- remove __ prefix from displayid_iter_block

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/da3dead1752ab16c061f7bd248ac1a4268f7fefb.1617024940.git.jani.nikula@intel.com

drm/displayid: add separate drm_displayid.c

We'll be adding more DisplayID specific functions going forward, so
start off by splitting out a few functions to a separate file.

We don't bother with exporting the functions; at least for now they
should be needed solely within drm.ko.

No functional changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/07942d5011891b8e8f77245c78b34f4af97a9315.1617024940.git.jani.nikula@intel.com

drm/edid: make a number of functions, parameters and variables const

If there's no need to change it, it should be const. There's more to be
done, but start off with changes that make follow-up work easier. No
functional changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/41722f92ef81cd6adf65f936fcc5301418e1f94b.1617024940.git.jani.nikula@intel.com

drm/edid: Replace zero-length array with flexible-array

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

drm/edid: Swap some operands in for_each_displayid_db()

A+B on the previous line, B+A on the next line. Brain hurts.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313162054.16009-3-ville.syrjala@linux.intel.com
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

drm/edid: parse CEA blocks embedded in DisplayID

DisplayID blocks allow embedding of CEA blocks. The payloads are
identical to traditional top level CEA extension blocks, but the header
is slightly different.

This change allows the CEA parser to find a CEA block inside a DisplayID
block. Additionally, it adds support for parsing the embedded CTA
header. No further changes are necessary due to payload parity.

This change fixes audio support for the Valve Index HMD.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.15
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190619180901.17901-1-andresx7@gmail.com

drm/edid: add displayid detailed 1 timings to the modelist. (v1.1)

The tiled 5K Dell monitor appears to be hiding it's tiled mode
inside the displayid timings block, this patch parses this
blocks and adds the modes to the modelist.

v1.1: add missing __packed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95207
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/displayid: add displayid defines and edid extension (v2)

These are just taken from the DisplayID v1.3 spec, and the
DDC spec.

v2: use __packed (Jani)

Signed-off-by: Dave Airlie <airlied@redhat.com>