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author | Jani Nikula <jani.nikula@intel.com> | 2021-03-29 16:37:17 +0300 |
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committer | Jani Nikula <jani.nikula@intel.com> | 2021-03-31 15:41:43 +0300 |
commit | 1a24c364e48414c6bd16f867c115cb3f4ad1aecc (patch) | |
tree | 5406e849ad73386da2ca78d8e1d5060ddef7c7c7 /include/drm/drm_displayid.h | |
parent | 4cc4f09eaa06178bfa8a5b2c753cefb56e1048c8 (diff) | |
download | linux-1a24c364e48414c6bd16f867c115cb3f4ad1aecc.tar.bz2 |
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
Diffstat (limited to 'include/drm/drm_displayid.h')
-rw-r--r-- | include/drm/drm_displayid.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h index 3c6db22a518a..27e06c98db17 100644 --- a/include/drm/drm_displayid.h +++ b/include/drm/drm_displayid.h @@ -108,4 +108,22 @@ const u8 *drm_find_displayid_extension(const struct edid *edid, int *length, int *idx, int *ext_index); +/* DisplayID iteration */ +struct displayid_iter { + const struct edid *edid; + + const u8 *section; + int length; + int idx; + int ext_index; +}; + +void displayid_iter_edid_begin(const struct edid *edid, + struct displayid_iter *iter); +const struct displayid_block * +__displayid_iter_next(struct displayid_iter *iter); +#define displayid_iter_for_each(__block, __iter) \ + while (((__block) = __displayid_iter_next(__iter))) +void displayid_iter_end(struct displayid_iter *iter); + #endif |