From: Ankit Nautiyal ankit.k.nautiyal@intel.com
Add helper functions for calculating FRL capacity and DFM requirements with given compressed bpp.
Signed-off-by: Ankit Nautiyal ankit.k.nautiyal@intel.com Signed-off-by: Vandita Kulkarni vandita.kulkarni@intel.com --- drivers/gpu/drm/drm_frl_dfm_helper.c | 298 +++++++++++++++++++++++++++ include/drm/drm_frl_dfm_helper.h | 3 + 2 files changed, 301 insertions(+)
diff --git a/drivers/gpu/drm/drm_frl_dfm_helper.c b/drivers/gpu/drm/drm_frl_dfm_helper.c index 087905ed630a..dbdcc509f791 100644 --- a/drivers/gpu/drm/drm_frl_dfm_helper.c +++ b/drivers/gpu/drm/drm_frl_dfm_helper.c @@ -555,3 +555,301 @@ drm_frl_dfm_nondsc_requirement_met(struct drm_hdmi_frl_dfm *frl_dfm) return false; } EXPORT_SYMBOL(drm_frl_dfm_nondsc_requirement_met); + +/* DSC DFM functions */ +/* Get FRL Available characters */ +static u32 +drm_get_frl_available_chars(u32 overhead_max, u32 cfrl_line) +{ + u32 frl_char_avlb = ((EFFICIENCY_MULTIPLIER - overhead_max) * cfrl_line); + + return frl_char_avlb / EFFICIENCY_MULTIPLIER; +} + +/* Get required no. of tribytes during HCActive */ +static u32 +drm_get_frl_hcactive_tb_target(u32 dsc_bpp_x16, u32 slice_width, u32 num_slices) +{ + u32 bytes_target; + + bytes_target = num_slices * DIV_ROUND_UP(dsc_bpp_x16 * slice_width, + 8 * BPP_MULTIPLIER); + + return DIV_ROUND_UP(bytes_target, 3); +} + +/* Get required no. of tribytes (estimate1) during HCBlank */ +static u32 +drm_get_frl_hcblank_tb_est1_target(u32 hcactive_target_tb, + u32 hactive, u32 hblank) +{ + return DIV_ROUND_UP(hcactive_target_tb * hblank, hactive); +} + +/* Get required no. of tribytes during HCBlank */ +static u32 +drm_get_frl_hcblank_tb_target(u32 hcactive_target_tb, u32 hactive, u32 hblank, + u32 hcblank_audio_min, u32 cfrl_available) +{ + u32 hcblank_target_tb1 = drm_get_frl_hcblank_tb_est1_target(hcactive_target_tb, + hactive, hblank); + u32 hcblank_target_tb2 = max(hcblank_target_tb1, hcblank_audio_min); + + return 4 * (min(hcblank_target_tb2, + (2 * cfrl_available - 3 * hcactive_target_tb) / 2) / 4); +} + +/* Get the avg no of tribytes sent per sec (Kbps) */ +static u64 +drm_frl_dsc_get_ftb_avg(u32 hcactive_target_tb, u32 hcblank_target_tb, + u32 hactive, u32 hblank, + u64 fpixelclock_max_khz) +{ + return (hcactive_target_tb + hcblank_target_tb) * (fpixelclock_max_khz / (hactive + hblank)); +} + +/* Time to send Active tribytes in nanoseconds */ +static u32 +drm_frl_dsc_get_tactive_ref_ns(u32 line_time_ns, u32 hactive, u32 hblank) +{ + return (line_time_ns * hactive) / (hactive + hblank); +} + +/* Time to send Blanking tribytes in nanoseconds */ +static u32 +drm_frl_dsc_get_tblank_ref_ns(u32 line_time_ns, u32 hactive, u32 hblank) +{ + return (line_time_ns * hblank) / (hactive + hblank); +} + +/* Get time to send all tribytes in hcactive region in nsec*/ +static u32 +drm_frl_dsc_tactive_target_ns(u32 frl_lanes, u32 hcactive_target_tb, u64 ftb_avg_k, + u32 min_frl_char_rate_k, u32 overhead_max) +{ + u32 avg_tribyte_time_ns, tribyte_time_ns; + u32 num_chars_hcactive; + u32 frl_char_rate_k; + + /* Avg time to transmit all active region tribytes */ + avg_tribyte_time_ns = (hcactive_target_tb * FRL_TIMING_NS_MULTIPLIER) / + (ftb_avg_k * 1000); + + /* + * 2 bytes in active region = 1 FRL characters + * 1 Tribyte in active region = 3/2 FRL characters + */ + + num_chars_hcactive = (hcactive_target_tb * 3) / 2; + + /* + * FRL rate = lanes * frl character rate + * But actual bandwidth wil be less, due to FRL limitations so account + * for the overhead involved. + * FRL rate with overhead = FRL rate * (100 - overhead %) / 100 + */ + frl_char_rate_k = frl_lanes * min_frl_char_rate_k; + frl_char_rate_k = (frl_char_rate_k * (EFFICIENCY_MULTIPLIER - overhead_max)) / + EFFICIENCY_MULTIPLIER; + + /* Time to transmit all characters with FRL limitations */ + tribyte_time_ns = (num_chars_hcactive * FRL_TIMING_NS_MULTIPLIER) / + frl_char_rate_k * 1000; + + return max(avg_tribyte_time_ns, tribyte_time_ns); +} + +/* Get no. of tri bytes borrowed with DSC enabled */ +static u32 +drm_frl_get_dsc_tri_bytes_borrowed(u32 tactive_target_ns, u32 ftb_avg_k, + u32 hcactive_target_tb) +{ + return (tactive_target_ns * FRL_TIMING_NS_MULTIPLIER * ftb_avg_k * 1000) - + hcactive_target_tb; +} + +/* Get TBdelta */ +static u32 +drm_frl_get_dsc_tri_bytes_delta(u32 tactive_target_ns, u32 tactive_ref_ns, + u32 hcactive_target_tb, u32 ftb_avg_k, + u32 hactive, u32 hblank, u32 line_time_ns) +{ + u32 tb_delta_limit; + u32 tblank_target_ns = line_time_ns - tactive_target_ns; + u32 tblank_ref_ns = line_time_ns - tactive_ref_ns; + u32 hcblank_target_tb1 = drm_get_frl_hcblank_tb_est1_target(hcactive_target_tb, + hactive, hblank); + + if (tblank_ref_ns < tblank_target_ns) { + tb_delta_limit = (((tactive_ref_ns * FRL_TIMING_NS_MULTIPLIER) - (hcactive_target_tb/(ftb_avg_k * 1000))) * + (hcactive_target_tb + hcblank_target_tb1)) / + (line_time_ns * FRL_TIMING_NS_MULTIPLIER); + } else { + u32 _tb_delta_ns; + + if (tactive_target_ns > tactive_ref_ns) + _tb_delta_ns = tactive_target_ns - tactive_ref_ns; + else + _tb_delta_ns = tactive_ref_ns - tactive_target_ns; + tb_delta_limit = (_tb_delta_ns * (hcactive_target_tb + hcblank_target_tb1)) / line_time_ns; + } + + return tb_delta_limit; +} + +/* Compute hcactive and hcblank tribytes for given dsc bpp setting */ +static void +drm_frl_dfm_dsc_compute_tribytes(struct drm_hdmi_frl_dfm *frl_dfm) +{ + + u32 hcactive_target_tb; + u32 hcblank_target_tb; + u32 cfrl_available; + u32 num_slices; + + /* Assert for slice width ?*/ + if (!frl_dfm->config.slice_width) + return; + + num_slices = DIV_ROUND_UP(frl_dfm->config.hactive, frl_dfm->config.slice_width); + + hcactive_target_tb = drm_get_frl_hcactive_tb_target(frl_dfm->config.target_bpp_16, + frl_dfm->config.slice_width, + num_slices); + + cfrl_available = + drm_get_frl_available_chars(frl_dfm->params.overhead_max, + frl_dfm->params.cfrl_line); + + hcblank_target_tb = + drm_get_frl_hcblank_tb_target(hcactive_target_tb, + frl_dfm->config.hactive, + frl_dfm->config.hblank, + frl_dfm->params.hblank_audio_min, + cfrl_available); + + frl_dfm->params.hcactive_target = hcactive_target_tb; + frl_dfm->params.hcblank_target = hcblank_target_tb; +} + +/* Check if audio supported with given dsc bpp and frl bandwidth */ +static bool +drm_frl_dfm_dsc_audio_supported(struct drm_hdmi_frl_dfm *frl_dfm) +{ + return frl_dfm->params.hcblank_target < frl_dfm->params.hblank_audio_min; +} + +/* Is DFM timing requirement is met with DSC */ +static +bool drm_frl_dfm_dsc_is_timing_req_met(struct drm_hdmi_frl_dfm *frl_dfm) +{ + u32 ftb_avg_k; + u32 tactive_ref_ns, tblank_ref_ns, tactive_target_ns, tblank_target_ns; + u32 tb_borrowed, tb_delta, tb_worst; + + ftb_avg_k = drm_frl_dsc_get_ftb_avg(frl_dfm->params.hcactive_target, + frl_dfm->params.hcblank_target, + frl_dfm->config.hactive, + frl_dfm->config.hblank, + frl_dfm->params.pixel_clock_max_khz); + + tactive_ref_ns = drm_frl_dsc_get_tactive_ref_ns(frl_dfm->params.line_time_ns, + frl_dfm->config.hactive, + frl_dfm->config.hblank); + + tblank_ref_ns = drm_frl_dsc_get_tblank_ref_ns(frl_dfm->params.line_time_ns, + frl_dfm->config.hactive, + frl_dfm->config.hblank); + + tactive_target_ns = drm_frl_dsc_tactive_target_ns(frl_dfm->config.lanes, + frl_dfm->params.hcactive_target, + ftb_avg_k, + frl_dfm->params.char_rate_min_kbps, + frl_dfm->params.overhead_max); + + tblank_target_ns = frl_dfm->params.line_time_ns - tactive_target_ns; + + tb_borrowed = drm_frl_get_dsc_tri_bytes_borrowed(tactive_target_ns, + ftb_avg_k, + frl_dfm->params.hcactive_target); + + tb_delta = drm_frl_get_dsc_tri_bytes_delta(tactive_target_ns, + tactive_ref_ns, + frl_dfm->params.hcactive_target, + ftb_avg_k, + frl_dfm->config.hactive, + frl_dfm->config.hblank, + frl_dfm->params.line_time_ns); + + tb_worst = max(tb_borrowed, tb_delta); + if (tb_worst > TB_BORROWED_MAX) + return false; + + frl_dfm->params.ftb_avg_k = ftb_avg_k; + frl_dfm->params.tb_borrowed = tb_borrowed; + + return true; +} + +/* Check Utilization constraint with DSC */ +static bool +drm_frl_dsc_check_utilization(struct drm_hdmi_frl_dfm *frl_dfm) +{ + u32 hcactive_target_tb = frl_dfm->params.hcactive_target; + u32 hcblank_target_tb = frl_dfm->params.hcblank_target; + u32 frl_char_per_line = frl_dfm->params.cfrl_line; + u32 overhead_max = frl_dfm->params.overhead_max; + u32 actual_frl_char_payload; + u32 utilization; + u32 utilization_with_overhead; + + /* Note: + * 1 FRL characters per 2 bytes in active period + * 1 FRL char per byte in Blanking period + */ + actual_frl_char_payload = DIV_ROUND_UP(3 * hcactive_target_tb, 2) + + hcblank_target_tb; + + utilization = (actual_frl_char_payload * EFFICIENCY_MULTIPLIER) / + frl_char_per_line; + + /* + * Utilization with overhead = utlization% +overhead % + * should be less than 100% + */ + utilization_with_overhead = utilization + overhead_max; + if (utilization_with_overhead > EFFICIENCY_MULTIPLIER) + return false; + + return false; +} + +/* + * drm_frl_fm_dsc_requirement_met : Check if FRL DFM requirements are met with + * the given bpp. + * @frl_dfm: dfm structure + * + * Returns true if the frl dfm requirements are met, else returns false. + */ +bool drm_frl_dfm_dsc_requirement_met(struct drm_hdmi_frl_dfm *frl_dfm) +{ + if (!frl_dfm->config.slice_width || !frl_dfm->config.target_bpp_16) + return false; + + drm_frl_dfm_compute_max_frl_link_overhead(frl_dfm); + drm_frl_dfm_compute_link_characteristics(frl_dfm); + drm_frl_dfm_compute_audio_hblank_min(frl_dfm); + drm_frl_dfm_dsc_compute_tribytes(frl_dfm); + + if (!drm_frl_dfm_dsc_audio_supported(frl_dfm)) + return false; + + if (!drm_frl_dfm_dsc_is_timing_req_met(frl_dfm)) + return false; + + if (!drm_frl_dsc_check_utilization(frl_dfm)) + return false; + + return true; +} +EXPORT_SYMBOL(drm_frl_dfm_dsc_requirement_met); diff --git a/include/drm/drm_frl_dfm_helper.h b/include/drm/drm_frl_dfm_helper.h index f36b6898e9dd..5430b9044d63 100644 --- a/include/drm/drm_frl_dfm_helper.h +++ b/include/drm/drm_frl_dfm_helper.h @@ -125,4 +125,7 @@ struct drm_hdmi_frl_dfm {
bool drm_frl_dfm_nondsc_requirement_met(struct drm_hdmi_frl_dfm *frl_dfm);
+bool +drm_frl_dfm_dsc_requirement_met(struct drm_hdmi_frl_dfm *frl_dfm); + #endif