diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_helper.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 8d6ce46471ae..6c91f400ecb1 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -2914,6 +2914,84 @@ void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc) EXPORT_SYMBOL(drm_dp_vsc_sdp_log); /** + * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp + * @vsc: vsc sdp initialized according to its purpose as defined in + * table 2-118 - table 2-120 in DP 1.4a specification + * @sdp: valid handle to the generic dp_sdp which will be packed + * @size: valid size of the passed sdp handle + * + * Returns length of sdp on success and error code on failure + */ +ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, + struct dp_sdp *sdp, size_t size) +{ + size_t length = sizeof(struct dp_sdp); + + if (size < length) + return -ENOSPC; + + memset(sdp, 0, size); + + /* + * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119 + * VSC SDP Header Bytes + */ + sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */ + sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */ + sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */ + sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */ + + if (vsc->revision == 0x6) { + sdp->db[0] = 1; + sdp->db[3] = 1; + } + + /* + * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry + * Format as per DP 1.4a spec and DP 2.0 respectively. + */ + if (!(vsc->revision == 0x5 || vsc->revision == 0x7)) + goto out; + + /* VSC SDP Payload for DB16 through DB18 */ + /* Pixel Encoding and Colorimetry Formats */ + sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */ + sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */ + + switch (vsc->bpc) { + case 6: + /* 6bpc: 0x0 */ + break; + case 8: + sdp->db[17] = 0x1; /* DB17[3:0] */ + break; + case 10: + sdp->db[17] = 0x2; + break; + case 12: + sdp->db[17] = 0x3; + break; + case 16: + sdp->db[17] = 0x4; + break; + default: + WARN(1, "Missing case %d\n", vsc->bpc); + return -EINVAL; + } + + /* Dynamic Range and Component Bit Depth */ + if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA) + sdp->db[17] |= 0x80; /* DB17[7] */ + + /* Content Type */ + sdp->db[18] = vsc->content_type & 0x7; + +out: + return length; +} +EXPORT_SYMBOL(drm_dp_vsc_sdp_pack); + +/** * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON * @dpcd: DisplayPort configuration data * @port_cap: port capabilities |