Initialize the source audio capabilities for HDMI in crtc_state
property by setting them to their maximum supported values,
including max_channel and max_frequency. This allows for the
calculation of HDMI audio source capabilities with respect to
the available mode bandwidth. These capabilities encompass
parameters such as supported frequency and channel configurations.

--v1:
- Refactor max_channel and max_rate to this commit as it is being
initialised here
- Remove call for intel_audio_compute_eld to avoid any regression while
merge. instead call it in different commit when it is defined.
- Use int instead of unsigned int for max_channel and max_frequecy
- Update commit message and header

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.gol...@intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  6 ++++
 drivers/gpu/drm/i915/display/intel_hdmi.c     | 35 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_hdmi.h     |  1 +
 3 files changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h 
b/drivers/gpu/drm/i915/display/intel_display_types.h
index ebd147180a6e..74eee87d2df1 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1131,6 +1131,12 @@ struct intel_crtc_state {
 
        struct {
                bool has_audio;
+
+               /* Audio rate in Hz */
+               int max_frequency;
+
+               /* Number of audio channels */
+               int max_channel;
        } audio;
 
        /*
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c 
b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 32157bef2eef..0188a600f9f5 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2277,6 +2277,40 @@ bool intel_hdmi_compute_has_hdmi_sink(struct 
intel_encoder *encoder,
                !intel_hdmi_is_cloned(crtc_state);
 }
 
+static unsigned int calc_audio_bw(int channel, int frequency)
+{
+       int bits_per_sample = 32;
+       unsigned int bandwidth = channel * frequency * bits_per_sample;
+       return bandwidth;
+}
+
+void
+intel_hdmi_audio_compute_config(struct intel_crtc_state *pipe_config)
+{
+       struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
+       int num_of_channel, aud_rates[7] = {192000, 176000, 96000, 88000, 
48000, 44100, 32000};
+       unsigned int audio_req_bandwidth, available_blank_bandwidth, vblank, 
hblank;
+
+       hblank = adjusted_mode->htotal - adjusted_mode->hdisplay;
+       vblank = adjusted_mode->vtotal - adjusted_mode->vdisplay;
+       available_blank_bandwidth = hblank * vblank *
+                                   drm_mode_vrefresh(adjusted_mode) * 
pipe_config->pipe_bpp;
+       for (num_of_channel = 8; num_of_channel > 0; num_of_channel--) {
+               for (int index = 0; index < 7; index++) {
+                       audio_req_bandwidth = calc_audio_bw(num_of_channel,
+                                                           aud_rates[index]);
+                       if (audio_req_bandwidth < available_blank_bandwidth) {
+                               pipe_config->audio.max_frequency = 
aud_rates[index];
+                               pipe_config->audio.max_channel = num_of_channel;
+                               return;
+                       }
+               }
+       }
+
+       pipe_config->audio.max_frequency = 0;
+       pipe_config->audio.max_channel = 0;
+}
+
 int intel_hdmi_compute_config(struct intel_encoder *encoder,
                              struct intel_crtc_state *pipe_config,
                              struct drm_connector_state *conn_state)
@@ -2344,6 +2378,7 @@ int intel_hdmi_compute_config(struct intel_encoder 
*encoder,
                        pipe_config->hdmi_high_tmds_clock_ratio = true;
                }
        }
+       intel_hdmi_audio_compute_config(pipe_config);
 
        intel_hdmi_compute_gcp_infoframe(encoder, pipe_config,
                                         conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.h 
b/drivers/gpu/drm/i915/display/intel_hdmi.h
index 6b39df38d57a..6df303daf348 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.h
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.h
@@ -27,6 +27,7 @@ void intel_hdmi_init_connector(struct intel_digital_port 
*dig_port,
 bool intel_hdmi_compute_has_hdmi_sink(struct intel_encoder *encoder,
                                      const struct intel_crtc_state *crtc_state,
                                      const struct drm_connector_state 
*conn_state);
+void intel_hdmi_audio_compute_config(struct intel_crtc_state *pipe_config);
 int intel_hdmi_compute_config(struct intel_encoder *encoder,
                              struct intel_crtc_state *pipe_config,
                              struct drm_connector_state *conn_state);
-- 
2.25.1

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