From: Guillaume Ranquet <redacted>

This patch adds two helper functions that extract the frequency and word
length from a struct cea_sad.

For these helper functions new defines are added that help translate the
'freq' and 'byte2' fields into real numbers.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Guillaume Ranquet <redacted>
Signed-off-by: Bo-Chen Chen <redacted>
---
  drivers/gpu/drm/drm_edid.c | 73 ++++++++++++++++++++++++++++++++++++++
  include/drm/drm_edid.h     | 14 ++++++++
  2 files changed, 87 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index bc43e1b32092..79316d7f1fd8 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c

@@ -4916,6 +4916,79 @@ int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb)
  }
  EXPORT_SYMBOL(drm_edid_to_speaker_allocation);
  
+/**
+ * drm_cea_sad_get_sample_rate - Extract the sample rate from cea_sad
+ * @sad: Pointer to the cea_sad struct
+ *
+ * Extracts the cea_sad frequency field and returns the sample rate in Hz.
+ *
+ * Return: Sample rate in Hz or a negative errno if parsing failed.
+ */
+int drm_cea_sad_get_sample_rate(const struct cea_sad *sad)
+{
+	switch (sad->freq) {
+	case DRM_CEA_SAD_FREQ_32KHZ:
+		return 32000;
+	case DRM_CEA_SAD_FREQ_44KHZ:
+		return 44100;
+	case DRM_CEA_SAD_FREQ_48KHZ:
+		return 48000;
+	case DRM_CEA_SAD_FREQ_88KHZ:
+		return 88200;
+	case DRM_CEA_SAD_FREQ_96KHZ:
+		return 96000;
+	case DRM_CEA_SAD_FREQ_176KHZ:
+		return 176400;
+	case DRM_CEA_SAD_FREQ_192KHZ:
+		return 192000;
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(drm_cea_sad_get_sample_rate);
+
+static bool drm_cea_sad_is_pcm(const struct cea_sad *sad)
+{
+	switch (sad->format) {
+	case HDMI_AUDIO_CODING_TYPE_PCM:
+		return true;
+	default:
+		return false;
+	}