From: Markus Schneider-Pargmann <msp@baylibre.com>
To: Chun-Kuang Hu <chunkuang.hu@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org,
linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
Markus Schneider-Pargmann <msp@baylibre.com>
Subject: [RFC PATCH 3/5] drm/edid: Add cea_sad helpers for freq/length
Date: Mon, 16 Aug 2021 21:25:21 +0200 [thread overview]
Message-ID: <20210816192523.1739365-4-msp@baylibre.com> (raw)
In-Reply-To: <20210816192523.1739365-1-msp@baylibre.com>
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>
---
drivers/gpu/drm/drm_edid.c | 57 ++++++++++++++++++++++++++++++++++++++
include/drm/drm_edid.h | 18 ++++++++++--
2 files changed, 73 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 81d5f2524246..2389d34ce10e 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4666,6 +4666,63 @@ int drm_edid_to_speaker_allocation(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(struct cea_sad *sad)
+{
+ switch (sad->freq) {
+ case CEA_SAD_FREQ_32KHZ:
+ return 32000;
+ case CEA_SAD_FREQ_44KHZ:
+ return 44100;
+ case CEA_SAD_FREQ_48KHZ:
+ return 48000;
+ case CEA_SAD_FREQ_88KHZ:
+ return 88200;
+ case CEA_SAD_FREQ_96KHZ:
+ return 96000;
+ case CEA_SAD_FREQ_176KHZ:
+ return 176400;
+ case CEA_SAD_FREQ_192KHZ:
+ return 192000;
+ default:
+ return -EINVAL;
+ }
+}
+EXPORT_SYMBOL(drm_cea_sad_get_sample_rate);
+
+/**
+ * drm_cea_sad_get_uncompressed_word_length - Extract word length
+ * @sad: Pointer to the cea_sad struct
+ *
+ * Extracts the cea_sad byte2 field and returns the word length for an
+ * uncompressed stream.
+ *
+ * Note: This function may only be called for uncompressed audio.
+ *
+ * Return: Word length in bits or a negative errno if parsing failed.
+ */
+int drm_cea_sad_get_uncompressed_word_length(struct cea_sad *sad)
+{
+ switch (sad->byte2) {
+ case CEA_SAD_UNCOMPRESSED_WORD_16BIT:
+ return 16;
+ case CEA_SAD_UNCOMPRESSED_WORD_20BIT:
+ return 20;
+ case CEA_SAD_UNCOMPRESSED_WORD_24BIT:
+ return 24;
+ default:
+ return -EINVAL;
+ }
+}
+EXPORT_SYMBOL(drm_cea_sad_get_uncompressed_word_length);
+
/**
* drm_av_sync_delay - compute the HDMI/DP sink audio-video sync delay
* @connector: connector associated with the HDMI/DP sink
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 759328a5eeb2..bed091a749ef 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -361,12 +361,24 @@ struct edid {
/* Short Audio Descriptor */
struct cea_sad {
- u8 format;
+ u8 format; /* See HDMI_AUDIO_CODING_TYPE_* */
u8 channels; /* max number of channels - 1 */
- u8 freq;
+ u8 freq; /* See CEA_SAD_FREQ_* */
u8 byte2; /* meaning depends on format */
};
+#define CEA_SAD_FREQ_32KHZ BIT(0)
+#define CEA_SAD_FREQ_44KHZ BIT(1)
+#define CEA_SAD_FREQ_48KHZ BIT(2)
+#define CEA_SAD_FREQ_88KHZ BIT(3)
+#define CEA_SAD_FREQ_96KHZ BIT(4)
+#define CEA_SAD_FREQ_176KHZ BIT(5)
+#define CEA_SAD_FREQ_192KHZ BIT(6)
+
+#define CEA_SAD_UNCOMPRESSED_WORD_16BIT BIT(0)
+#define CEA_SAD_UNCOMPRESSED_WORD_20BIT BIT(1)
+#define CEA_SAD_UNCOMPRESSED_WORD_24BIT BIT(2)
+
struct drm_encoder;
struct drm_connector;
struct drm_connector_state;
@@ -374,6 +386,8 @@ struct drm_display_mode;
int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads);
int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb);
+int drm_cea_sad_get_sample_rate(struct cea_sad *sad);
+int drm_cea_sad_get_uncompressed_word_length(struct cea_sad *sad);
int drm_av_sync_delay(struct drm_connector *connector,
const struct drm_display_mode *mode);
--
2.32.0
next prev parent reply other threads:[~2021-08-16 19:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 19:25 [RFC PATCH 0/5] drm/mediatek: Add mt8195 DisplayPort driver Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 1/5] dt-bindings: mediatek,dpi: Add mt8195 dpintf Markus Schneider-Pargmann
2021-08-18 4:45 ` CK Hu
2021-08-18 7:30 ` Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 2/5] drm/mediatek: dpi: Add dpintf support Markus Schneider-Pargmann
2021-08-17 9:50 ` CK Hu
2021-08-18 7:26 ` Markus Schneider-Pargmann
2021-08-16 19:25 ` Markus Schneider-Pargmann [this message]
2021-08-16 19:25 ` [RFC PATCH 4/5] video/hdmi: Add audio_infoframe packing for DP Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 5/5] drm/mediatek: Add mt8195 DisplayPort driver Markus Schneider-Pargmann
2021-08-16 21:36 ` Sam Ravnborg
2021-08-17 7:31 ` Markus Schneider-Pargmann
2021-08-17 5:36 ` CK Hu
2021-08-17 7:35 ` Markus Schneider-Pargmann
2021-08-18 4:42 ` CK Hu
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