[PATCH v2] drm/edid: add CTA Video Format Data Block support
Hamza Mahfooz
hamza.mahfooz at amd.com
Fri Aug 2 15:53:53 UTC 2024
On 8/1/24 03:35, Jani Nikula wrote:
> On Wed, 31 Jul 2024, Hamza Mahfooz <hamza.mahfooz at amd.com> wrote:
>> Video Format Data Blocks (VFDBs) contain the necessary information that
>> needs to be fed to the Optimized Video Timings (OVT) Algorithm.
>> Also, we require OVT support to cover modes that aren't supported by
>> earlier standards (e.g. CVT). So, parse all of the relevant VFDB data
>> and feed it to the OVT Algorithm, to extract all of the missing OVT
>> modes.
>>
>> Suggested-by: Karol Herbst <kherbst at redhat.com>
>> Signed-off-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
>> ---
>> v2: address comments from Jani
>> ---
>> drivers/gpu/drm/drm_edid.c | 456 ++++++++++++++++++++++++++++++++++---
>> 1 file changed, 428 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index f68a41eeb1fa..f608ab4e32ae 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -31,6 +31,7 @@
>> #include <linux/bitfield.h>
>> #include <linux/byteorder/generic.h>
>> #include <linux/cec.h>
>> +#include <linux/gcd.h>
>> #include <linux/hdmi.h>
>> #include <linux/i2c.h>
>> #include <linux/kernel.h>
>> @@ -741,6 +742,93 @@ static const struct minimode extra_modes[] = {
>> { 2048, 1536, 60, 0 },
>> };
>>
>> +struct cta_rid {
>> + u16 hactive;
>> + u16 vactive;
>> + u8 hratio;
>> + u8 vratio;
>> +};
>> +
>> +/* CTA-861-I Table 11 - Resolution Identification (RID) */
>> +static const struct cta_rid rids[] = {
>> + /* RID 0-9 */
>> + { 0, 0, 0, 0 },
>> + { 1280, 720, 16, 9 },
>> + { 1280, 720, 64, 27 },
>> + { 1680, 720, 64, 27 },
>> + { 1920, 1080, 16, 9 },
>> + { 1920, 1080, 64, 27 },
>> + { 2560, 1080, 64, 27 },
>> + { 3840, 1080, 32, 9 },
>> + { 2560, 1440, 16, 9 },
>> + { 3440, 1440, 64, 27 },
>> + /* RID 10-19 */
>> + { 5120, 1440, 32, 9 },
>> + { 3840, 2160, 16, 9 },
>> + { 3840, 2160, 64, 27 },
>> + { 5120, 2160, 64, 27 },
>> + { 7680, 2160, 32, 9 },
>> + { 5120, 2880, 16, 9 },
>> + { 5120, 2880, 64, 27 },
>> + { 6880, 2880, 64, 27 },
>> + { 10240, 2880, 32, 9 },
>> + { 7680, 4320, 16, 9 },
>> + /* RID 20-28 */
>> + { 7680, 4320, 64, 27 },
>> + { 10240, 4320, 64, 27 },
>> + { 15360, 4320, 32, 9 },
>> + { 11520, 6480, 16, 9 },
>> + { 11520, 6480, 64, 27 },
>> + { 15360, 6480, 64, 27 },
>> + { 15360, 8640, 16, 9 },
>> + { 15360, 8640, 64, 27 },
>> + { 20480, 8640, 64, 27 },
>> +};
>> +
>> +/* CTA-861-I Table 12 - AVI InfoFrame Video Format Frame Rate */
>> +static const u16 cta_vf_fr[] = {
>> + /* Frame Rate 0-7 */
>> + 0, 24, 25, 30, 48, 50, 60, 100,
>> + /* Frame Rate 8-15 */
>> + 120, 144, 200, 240, 300, 360, 400, 480,
>> +};
>> +
>> +/* CTA-861-I Table 13 - RID To VIC Mapping */
>> +static const u8 rid_to_vic[][8] = {
>> + /* RID 0-9 */
>> + {},
>> + { 60, 61, 62, 108, 19, 4, 41, 47 },
>> + { 65, 66, 67, 109, 68, 69, 70, 71 },
>> + { 79, 80, 81, 110, 82, 83, 84, 85 },
>> + { 32, 33, 34, 111, 31, 16, 64, 63 },
>> + { 72, 73, 74, 112, 75, 76, 77, 78 },
>> + { 86, 87, 88, 113, 89, 90, 91, 92 },
>> + {},
>> + {},
>> + {},
>> + /* RID 10-19 */
>> + {},
>> + { 93, 94, 95, 114, 96, 97, 117, 118 },
>> + { 103, 104, 105, 116, 106, 107, 119, 120 },
>> + { 121, 122, 123, 124, 125, 126, 127, 193 },
>> + {},
>> + {},
>> + {},
>> + {},
>> + {},
>> + { 194, 195, 196, 197, 198, 199, 200, 201 },
>> + /* RID 20-28 */
>> + { 202, 203, 204, 205, 206, 207, 208, 209 },
>> + { 210, 211, 212, 213, 214, 215, 216, 217 },
>> + {},
>> + {},
>> + {},
>> + {},
>> + {},
>> + {},
>> + {},
>> +};
>> +
>> /*
>> * From CEA/CTA-861 spec.
>> *
>> @@ -4140,6 +4228,7 @@ static int add_detailed_modes(struct drm_connector *connector,
>> #define CTA_DB_VIDEO 2
>> #define CTA_DB_VENDOR 3
>> #define CTA_DB_SPEAKER 4
>> +#define CTA_DB_VIDEO_FORMAT 6
>> #define CTA_DB_EXTENDED_TAG 7
>>
>> /* CTA-861-H Table 62 - CTA Extended Tag Codes */
>> @@ -4981,6 +5070,16 @@ struct cea_db {
>> u8 data[];
>> } __packed;
>>
>> +struct cta_vfd {
>> + u8 rid;
>> + u8 fr_fact;
>> + bool bfr50;
>> + bool fr24;
>> + bool bfr60;
>> + bool fr144;
>> + bool fr48;
>> +};
>> +
>> static int cea_db_tag(const struct cea_db *db)
>> {
>> return db->tag_length >> 5;
>> @@ -5306,34 +5405,6 @@ static void parse_cta_y420cmdb(struct drm_connector *connector,
>> *y420cmdb_map = map;
>> }
>>
>> -static int add_cea_modes(struct drm_connector *connector,
>> - const struct drm_edid *drm_edid)
>> -{
>> - const struct cea_db *db;
>> - struct cea_db_iter iter;
>> - int modes;
>> -
>> - /* CTA VDB block VICs parsed earlier */
>> - modes = add_cta_vdb_modes(connector);
>> -
>> - cea_db_iter_edid_begin(drm_edid, &iter);
>> - cea_db_iter_for_each(db, &iter) {
>> - if (cea_db_is_hdmi_vsdb(db)) {
>> - modes += do_hdmi_vsdb_modes(connector, (const u8 *)db,
>> - cea_db_payload_len(db));
>> - } else if (cea_db_is_y420vdb(db)) {
>> - const u8 *vdb420 = cea_db_data(db) + 1;
>> -
>> - /* Add 4:2:0(only) modes present in EDID */
>> - modes += do_y420vdb_modes(connector, vdb420,
>> - cea_db_payload_len(db) - 1);
>> - }
>> - }
>> - cea_db_iter_end(&iter);
>> -
>> - return modes;
>> -}
>> -
>
> Is there anything that really requires moving add_cea_modes() down? You
> could just add your new stuff above it, right?
>
> Again, I'll reply with further comments when I've tracked down a more
> recent spec...
You can obtain the latest (complete) spec from the following link btw:
https://shop.cta.tech/products/a-dtv-profile-for-uncompressed-high-speed-digital-interfaces-ansi-cta-861-i
>
> BR,
> Jani.
>
>> static void fixup_detailed_cea_mode_clock(struct drm_connector *connector,
>> struct drm_display_mode *mode)
>> {
>> @@ -6018,6 +6089,305 @@ static void parse_cta_vdb(struct drm_connector *connector, const struct cea_db *
>> }
>> }
>>
>> +/* CTA-861 Video Format Descriptor (CTA VFD) */
>> +static void parse_cta_vfd(struct cta_vfd *vfd, const u8 *data, int vfd_len)
>> +{
>> + vfd->rid = data[0] & 0x3f;
>> + vfd->bfr50 = data[0] & 0x80;
>> + vfd->fr24 = data[0] & 0x40;
>> + vfd->bfr60 = vfd_len > 1 ? (data[1] & 0x80) : 0x1;
>> + vfd->fr144 = vfd_len > 1 ? (data[1] & 0x40) : 0x0;
>> + vfd->fr_fact = vfd_len > 1 ? (data[1] & 0x3f) : 0x3;
>> + vfd->fr48 = vfd_len > 2 ? (data[2] & 0x1) : 0x0;
>> +}
>> +
>> +static bool vfd_has_fr(const struct cta_vfd *vfd, int rate_idx)
>> +{
>> + static const u8 factors[] = {
>> + 1, 2, 4, 8, 12, 16
>> + };
>> + u16 rate = cta_vf_fr[rate_idx];
>> + u16 factor = 0;
>> + unsigned int i;
>> +
>> + switch (rate) {
>> + case 24:
>> + return vfd->fr24;
>> + case 48:
>> + return vfd->fr48;
>> + case 144:
>> + return vfd->fr144;
>> + }
>> +
>> + if (!(rate % 25)) {
>> + if (!vfd->bfr50)
>> + return false;
>> +
>> + factor = rate / 25;
>> + } else if (!(rate % 30)) {
>> + if (!vfd->bfr60)
>> + return false;
>> +
>> + factor = rate / 30;
>> + }
>> +
>> + for (i = 0; i < ARRAY_SIZE(factors); i++)
>> + if (factor == factors[i] && (vfd->fr_fact & (1 << i)))
>> + return true;
>> +
>> + return false;
>> +}
>> +
>> +#define OVT_PIXEL_CLOCK_GRANULARITY 1000 /* Hz */
>> +#define OVT_MIN_HTOTAL_GRANULARITY 8 /* pixels */
>> +#define OVT_MIN_VBLANK_DURATION 460000000 /* ps */
>> +#define OVT_MIN_VBLANK_LINES 20
>> +#define OVT_MIN_VSYNC_LEADING_EDGE 400 /* us */
>> +#define OVT_MIN_VSYNC_LE_LINES 14
>> +#define OVT_MIN_CLOCK_RATE_420 590000000 /* Hz */
>> +#define OVT_PIXEL_FACTOR_420 2
>> +#define OVT_MIN_HBLANK_444 80 /* pixels */
>> +#define OVT_MIN_HBLANK_420 128 /* pixels */
>> +#define OVT_MAX_CHUNK_RATE 650000000 /* Hz */
>> +#define OVT_AUDIO_PACKET_RATE 195000 /* Hz */
>> +#define OVT_AUDIO_PACKET_SIZE 32
>> +#define OVT_LINE_OVERHEAD 32
>> +#define OVT_HSYNC_WIDTH 32
>> +#define OVT_VSYNC_WIDTH 8
>> +
>> +/* OVT Algorthim as specified in CTA-861-I */
>> +static struct drm_display_mode *
>> +calculate_ovt_mode(struct drm_connector *connector, const struct cta_rid *rid,
>> + u16 vrate)
>> +{
>> + u32 max_audio_packets_per_line;
>> + struct drm_display_mode *mode;
>> + u32 htotal_granularity_chunk;
>> + u32 resolution_granularity;
>> + u32 vtotal_granularity = 1;
>> + u64 min_pixel_clock_rate;
>> + u32 htotal_granularity;
>> + u32 max_vrate = vrate;
>> + u64 pixel_clock_rate;
>> + u64 max_active_time;
>> + u64 min_resolution;
>> + u32 vsync_position;
>> + u32 min_line_time;
>> + u32 min_line_rate;
>> + u32 min_hblank;
>> + u32 min_htotal;
>> + u32 min_vblank;
>> + u32 min_vtotal;
>> + u32 htotal;
>> + u32 vtotal;
>> + u32 h;
>> + u64 r;
>> + u32 v;
>> +
>> + /* step 1 */
>> + switch (vrate) {
>> + case 24:
>> + case 25:
>> + max_vrate = 30;
>> + fallthrough;
>> + case 30:
>> + vtotal_granularity = 20;
>> + break;
>> + case 48:
>> + case 50:
>> + max_vrate = 60;
>> + fallthrough;
>> + case 60:
>> + vtotal_granularity = 20;
>> + break;
>> + case 100:
>> + max_vrate = 120;
>> + fallthrough;
>> + case 120:
>> + vtotal_granularity = 5;
>> + break;
>> + case 200:
>> + max_vrate = 240;
>> + fallthrough;
>> + case 240:
>> + vtotal_granularity = 5;
>> + break;
>> + case 300:
>> + max_vrate = 360;
>> + fallthrough;
>> + case 360:
>> + vtotal_granularity = 5;
>> + break;
>> + case 400:
>> + max_vrate = 480;
>> + fallthrough;
>> + case 480:
>> + vtotal_granularity = 5;
>> + break;
>> + }
>> +
>> + /* step 2 */
>> + max_active_time = ((u64)1000000000000 / (u64)max_vrate) -
>> + (u64)OVT_MIN_VBLANK_DURATION;
>> +
>> + min_line_time = max_active_time / (u64)rid->vactive;
>> +
>> + min_vblank = max_t(u64, (u64)OVT_MIN_VBLANK_LINES,
>> + DIV64_U64_ROUND_UP(OVT_MIN_VBLANK_DURATION,
>> + min_line_time));
>> +
>> + min_vtotal = rid->vactive + min_vblank;
>> +
>> + if (min_vtotal % vtotal_granularity)
>> + min_vtotal += vtotal_granularity - (min_vtotal %
>> + vtotal_granularity);
>> +
>> + /* step 3 */
>> + min_line_rate = max_vrate * min_vtotal;
>> +
>> + max_audio_packets_per_line = DIV_ROUND_UP(OVT_AUDIO_PACKET_RATE,
>> + min_line_rate);
>> +
>> + /* step 4 */
>> + min_hblank = OVT_LINE_OVERHEAD + OVT_AUDIO_PACKET_SIZE *
>> + max_audio_packets_per_line;
>> +
>> + min_htotal = rid->hactive + max(OVT_MIN_HBLANK_444, min_hblank);
>> +
>> + min_pixel_clock_rate = max_vrate * min_htotal * min_vtotal;
>> +
>> + htotal_granularity_chunk =
>> + roundup_pow_of_two(DIV_ROUND_UP(min_pixel_clock_rate,
>> + OVT_MAX_CHUNK_RATE));
>> +
>> + htotal_granularity = max(OVT_MIN_HTOTAL_GRANULARITY,
>> + htotal_granularity_chunk);
>> +
>> + if (min_htotal % htotal_granularity)
>> + min_htotal += htotal_granularity - (min_htotal %
>> + htotal_granularity);
>> +
>> + resolution_granularity = OVT_PIXEL_CLOCK_GRANULARITY /
>> + gcd(OVT_PIXEL_CLOCK_GRANULARITY, max_vrate);
>> +
>> + do {
>> + /* step 5 */
>> + min_resolution = 0;
>> + v = min_vtotal;
>> +
>> + goto loop_end;
>> +
>> + while (!min_resolution || r <= min_resolution) {
>> + while (r % resolution_granularity ||
>> + max_vrate * r / (h & ~(h - 1)) >
>> + OVT_MAX_CHUNK_RATE) {
>> + h += htotal_granularity;
>> + r = (u64)h * (u64)v;
>> + }
>> +
>> + if (!min_resolution || r < min_resolution) {
>> + htotal = h;
>> + vtotal = v;
>> + min_resolution = r;
>> + }
>> +
>> + v += vtotal_granularity;
>> +
>> +loop_end:
>> + h = min_htotal;
>> + r = (u64)h * (u64)v;
>> + }
>> +
>> + pixel_clock_rate = max_vrate * min_resolution;
>> +
>> + /* step 6 */
>> + min_htotal = rid->hactive + max(OVT_MIN_HBLANK_420,
>> + OVT_PIXEL_FACTOR_420 *
>> + min_hblank);
>> + } while (pixel_clock_rate >= OVT_MIN_CLOCK_RATE_420 &&
>> + htotal < min_htotal);
>> +
>> + /* step 7 */
>> + vtotal = vtotal * max_vrate / vrate;
>> +
>> + /* step 8 */
>> + vsync_position = max(OVT_MIN_VSYNC_LE_LINES,
>> + DIV64_U64_ROUND_UP((u64)OVT_MIN_VSYNC_LE_LINES *
>> + (u64)pixel_clock_rate,
>> + (u64)htotal * (u64)1000000));
>> +
>> + mode = drm_mode_create(connector->dev);
>> +
>> + if (!mode)
>> + return NULL;
>> +
>> + mode->clock = pixel_clock_rate / 1000;
>> + mode->hdisplay = rid->hactive;
>> + mode->hsync_start = htotal - OVT_HSYNC_WIDTH * 2;
>> + mode->hsync_end = mode->hsync_start + OVT_HSYNC_WIDTH;
>> + mode->htotal = htotal;
>> +
>> + mode->vdisplay = rid->vactive;
>> + mode->vsync_start = vtotal - vsync_position;
>> + mode->vsync_end = mode->vsync_start + OVT_VSYNC_WIDTH;
>> + mode->vtotal = vtotal;
>> +
>> + return mode;
>> +}
>> +
>> +/* CTA-861 Video Format Data Block (CTA VFDB) */
>> +static int add_modes_from_vfdb(struct drm_connector *connector,
>> + const struct cea_db *db)
>> +{
>> + struct drm_display_info *info = &connector->display_info;
>> + int vfdb_len = cea_db_payload_len(db);
>> + struct drm_display_mode *mode;
>> + struct cta_vfd vfd;
>> + int num_modes = 0;
>> + int vfd_len;
>> + int i;
>> + int j;
>> +
>> + if (!vfdb_len)
>> + return 0;
>> +
>> + vfd_len = (db->data[0] & 0x3) + 1;
>> +
>> + if (!vfd_len)
>> + return 0;
>> +
>> + vfdb_len--;
>> +
>> + vfdb_len -= (vfdb_len % vfd_len);
>> +
>> + for (i = 0; i < vfdb_len; i += vfd_len) {
>> + parse_cta_vfd(&vfd, &db->data[i + 1], vfd_len);
>> +
>> + if (!vfd.rid || vfd.rid >= ARRAY_SIZE(rids))
>> + continue;
>> +
>> + for (j = 1; j < ARRAY_SIZE(cta_vf_fr); j++) {
>> + if (!vfd_has_fr(&vfd, j) ||
>> + (cta_vf_fr[j] < 144 && rid_to_vic[vfd.rid][j - 1]))
>> + continue;
>> +
>> + mode = calculate_ovt_mode(connector, &rids[vfd.rid],
>> + cta_vf_fr[j]);
>> +
>> + if (!mode)
>> + continue;
>> +
>> + mode->height_mm = info->height_mm;
>> + mode->width_mm = info->width_mm;
>> +
>> + drm_mode_probed_add(connector, mode);
>> + num_modes++;
>> + }
>> + }
>> +
>> + return num_modes;
>> +}
>> +
>> /*
>> * Update y420_cmdb_modes based on previously parsed CTA VDB and Y420CMDB.
>> *
>> @@ -6831,6 +7201,36 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
>> return num_modes;
>> }
>>
>> +static int add_cea_modes(struct drm_connector *connector,
>> + const struct drm_edid *drm_edid)
>> +{
>> + const struct cea_db *db;
>> + struct cea_db_iter iter;
>> + int modes;
>> +
>> + /* CTA VDB block VICs parsed earlier */
>> + modes = add_cta_vdb_modes(connector);
>> +
>> + cea_db_iter_edid_begin(drm_edid, &iter);
>> + cea_db_iter_for_each(db, &iter) {
>> + if (cea_db_is_hdmi_vsdb(db)) {
>> + modes += do_hdmi_vsdb_modes(connector, (const u8 *)db,
>> + cea_db_payload_len(db));
>> + } else if (cea_db_is_y420vdb(db)) {
>> + const u8 *vdb420 = cea_db_data(db) + 1;
>> +
>> + /* Add 4:2:0(only) modes present in EDID */
>> + modes += do_y420vdb_modes(connector, vdb420,
>> + cea_db_payload_len(db) - 1);
>> + } else if (cea_db_tag(db) == CTA_DB_VIDEO_FORMAT) {
>> + modes += add_modes_from_vfdb(connector, db);
>> + }
>> + }
>> + cea_db_iter_end(&iter);
>> +
>> + return modes;
>> +}
>> +
>> static int add_displayid_detailed_modes(struct drm_connector *connector,
>> const struct drm_edid *drm_edid)
>> {
>
--
Hamza
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