@@ -794,6 +794,72 @@ bool intel_audio_compute_config(struct intel_encoder *encoder,
return true;
}
+static unsigned int drm_sad_to_channels(const u8 *sad)
+{
+ return 1 + (sad[0] & 0x7);
+}
+
+static inline u8 *parse_sad(u8 *eld)
+{
+ unsigned int ver, mnl;
+
+ ver = (eld[DRM_ELD_VER] & DRM_ELD_VER_MASK) >> DRM_ELD_VER_SHIFT;
+ if (ver != 2 && ver != 31)
+ return NULL;
+
+ mnl = drm_eld_mnl(eld);
+ if (mnl > 16)
+ return NULL;
+
+ return eld + DRM_ELD_CEA_SAD(mnl, 0);
+}
+
+static u8 get_supported_freq_mask(struct intel_crtc_state *crtc_state)
+{
+ int audio_freq_hz[] = {32000, 44100, 48000, 88000, 96000, 176000, 192000, 0};
+ u8 mask = 0;
+
+ for (u8 index = 0; index < ARRAY_SIZE(audio_freq_hz); index++) {
+ mask |= 1 << index;
+ if (crtc_state->audio_config.max_frequency != audio_freq_hz[index])
+ continue;
+ else
+ break;
+ }
+
+ return mask;
+}
+
+void intel_audio_compute_eld(struct intel_crtc_state *crtc_state)
+{
+ struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+ u8 *eld, *sad, index, mask = 0;
+
+ eld = crtc_state->eld;
+ if (!eld) {
+ drm_err(&i915->drm, "failed to locate eld\n");
+ return;
+ }
+
+ sad = (u8 *)parse_sad(eld);
+ if (sad) {
+ mask = get_supported_freq_mask(crtc_state);
+
+ for (index = 0; index < drm_eld_sad_count(eld); index++, sad += 3) {
+ /*
+ * Respect to source restrictions. If source limit is greater than sink
+ * capabilities then follow to sink's highest supported rate.
+ */
+ if (drm_sad_to_channels(sad) >= crtc_state->audio_config.max_channel) {
+ sad[0] &= ~0x7;
+ sad[0] |= crtc_state->audio_config.max_channel - 1;
+ }
+
+ sad[1] &= mask;
+ }
+ }
+}
+
/**
* intel_audio_codec_enable - Enable the audio codec for HD audio
* @encoder: encoder on which to enable audio
@@ -14,6 +14,7 @@ struct intel_crtc_state;
struct intel_encoder;
void intel_audio_hooks_init(struct drm_i915_private *dev_priv);
+void intel_audio_compute_eld(struct intel_crtc_state *crtc_state);
bool intel_audio_compute_config(struct intel_encoder *encoder,
struct intel_crtc_state *crtc_state,
struct drm_connector_state *conn_state);
Compute SADs that takes into account the supported rate and channel based on the capabilities of the audio source. This wrapper function should encapsulate the logic for determining the supported rate and channel and should return a set of SADs that are compatible with the source. Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> --- drivers/gpu/drm/i915/display/intel_audio.c | 66 ++++++++++++++++++++++ drivers/gpu/drm/i915/display/intel_audio.h | 1 + 2 files changed, 67 insertions(+)