Il 12/07/22 13:12, Bo-Chen Chen ha scritto:
From: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>
---
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;
+ }
Are you sure that you need this helper? That's used only in one function...
...if you really need this one, though, I don't think that using a switch
is the best option here.
Unless anyone is against that (please, reason?), I would be for doing it like:
return sad->format == HDMI_AUDIO_CODING_TYPE_PCM;
Everything else looks good to me (and working, too).
Cheers,
Angelo
