drm/radeon: fix audio dto calculation on DCE3+ (v3)

Need to set the wallclock ratio and adjust the phase
and module registers appropriately.  May fix problems
with audio timing at certain display timings.

v2: properly handle clocks below 24mhz
v3: rebase r600 changes

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher
2013-07-30 17:31:07 -04:00
parent ce149a9406
commit 1518dd8efd
4 changed files with 59 additions and 6 deletions

View File

@@ -148,18 +148,40 @@ static void evergreen_audio_set_dto(struct drm_encoder *encoder, u32 clock)
struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
struct radeon_crtc *radeon_crtc = to_radeon_crtc(encoder->crtc);
u32 base_rate = 24000;
u32 max_ratio = clock / base_rate;
u32 dto_phase;
u32 dto_modulo = clock;
u32 wallclock_ratio;
u32 dto_cntl;
if (!dig || !dig->afmt)
return;
if (max_ratio >= 8) {
dto_phase = 192 * 1000;
wallclock_ratio = 3;
} else if (max_ratio >= 4) {
dto_phase = 96 * 1000;
wallclock_ratio = 2;
} else if (max_ratio >= 2) {
dto_phase = 48 * 1000;
wallclock_ratio = 1;
} else {
dto_phase = 24 * 1000;
wallclock_ratio = 0;
}
dto_cntl = RREG32(DCCG_AUDIO_DTO0_CNTL) & ~DCCG_AUDIO_DTO_WALLCLOCK_RATIO_MASK;
dto_cntl |= DCCG_AUDIO_DTO_WALLCLOCK_RATIO(wallclock_ratio);
WREG32(DCCG_AUDIO_DTO0_CNTL, dto_cntl);
/* XXX two dtos; generally use dto0 for hdmi */
/* Express [24MHz / target pixel clock] as an exact rational
* number (coefficient of two integer numbers. DCCG_AUDIO_DTOx_PHASE
* is the numerator, DCCG_AUDIO_DTOx_MODULE is the denominator
*/
WREG32(DCCG_AUDIO_DTO_SOURCE, DCCG_AUDIO_DTO0_SOURCE_SEL(radeon_crtc->crtc_id));
WREG32(DCCG_AUDIO_DTO0_PHASE, base_rate * 100);
WREG32(DCCG_AUDIO_DTO0_MODULE, clock * 100);
WREG32(DCCG_AUDIO_DTO0_PHASE, dto_phase);
WREG32(DCCG_AUDIO_DTO0_MODULE, dto_modulo);
}