From b1edd6a6ecd436af33f210a5c75e0249466fd200 Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Thu, 17 Jan 2013 16:31:30 +0200 Subject: drm/edid: Add drm_rgb_quant_range_selectable() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit drm_rgb_quant_range_selectable() will report whether the monitor claims to support for RGB quantization range selection. The information can be found in the CEA Video capability block. v2: s/quantzation/quantization/ in the comment Reviewed-by: Paulo Zanoni Signed-off-by: Ville Syrjälä Acked-by: David Airlie Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_edid.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'drivers/gpu/drm/drm_edid.c') diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 5a3770fbd77..a3a3b61059f 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1483,9 +1483,11 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid, #define VIDEO_BLOCK 0x02 #define VENDOR_BLOCK 0x03 #define SPEAKER_BLOCK 0x04 +#define VIDEO_CAPABILITY_BLOCK 0x07 #define EDID_BASIC_AUDIO (1 << 6) #define EDID_CEA_YCRCB444 (1 << 5) #define EDID_CEA_YCRCB422 (1 << 4) +#define EDID_CEA_VCDB_QS (1 << 6) /** * Search EDID for CEA extension block. @@ -1901,6 +1903,37 @@ end: } EXPORT_SYMBOL(drm_detect_monitor_audio); +/** + * drm_rgb_quant_range_selectable - is RGB quantization range selectable? + * + * Check whether the monitor reports the RGB quantization range selection + * as supported. The AVI infoframe can then be used to inform the monitor + * which quantization range (full or limited) is used. + */ +bool drm_rgb_quant_range_selectable(struct edid *edid) +{ + u8 *edid_ext; + int i, start, end; + + edid_ext = drm_find_cea_extension(edid); + if (!edid_ext) + return false; + + if (cea_db_offsets(edid_ext, &start, &end)) + return false; + + for_each_cea_db(edid_ext, i, start, end) { + if (cea_db_tag(&edid_ext[i]) == VIDEO_CAPABILITY_BLOCK && + cea_db_payload_len(&edid_ext[i]) == 2) { + DRM_DEBUG_KMS("CEA VCDB 0x%02x\n", edid_ext[i + 2]); + return edid_ext[i + 2] & EDID_CEA_VCDB_QS; + } + } + + return false; +} +EXPORT_SYMBOL(drm_rgb_quant_range_selectable); + /** * drm_add_display_info - pull display info out if present * @edid: EDID data -- cgit v1.2.3-70-g09d2