| Message ID | 20220523104758.29531-5-granquet@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: Add mt8195 DisplayPort driver | expand |
Il 23/05/22 12:47, Guillaume Ranquet ha scritto: > 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 <granquet@baylibre.com> > --- > drivers/gpu/drm/drm_edid.c | 74 ++++++++++++++++++++++++++++++++++++++ > include/drm/drm_edid.h | 14 ++++++++ > 2 files changed, 88 insertions(+) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index 561f53831e29..61ef1b1c972c 100644 > --- a/drivers/gpu/drm/drm_edid.c > +++ b/drivers/gpu/drm/drm_edid.c > @@ -4758,6 +4758,80 @@ 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(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_uncompressed(const struct cea_sad *sad) > +{ > + switch (sad->format) { > + case HDMI_AUDIO_CODING_TYPE_STREAM: As far as I know, bit 0 is reserved, so HDMI_AUDIO_CODING_TYPE_STREAM should never occur here? > + case HDMI_AUDIO_CODING_TYPE_PCM: > + return true; > + default: > + return false; > + } > +} > + Also, I think that implementing a drm_cea_sad_get_compressed_max_bitrate() function should be pretty straightforward... the spec says that this is 8 bits, byte 3 (your byte2) contains the max bitrate divided by 8kHz, so to extract it, you read byte2 and multiply it by 8000Hz. /** * drm_cea_sad_get_compressed_max_bitrate - Extract maximum bitrate * @sad: Pointer to the cea_sad structure * * Extracts the cea_sad byte2 field and returns the maximum bit rate * of a compressed audio stream. * * Note: This function may only be called for compressed audio. * * Return: Maximum bitrate of compressed audio stream in bit/s or * negative number for error */ int drm_cea_sad_get_compressed_max_bitrate(const struct cea_sad *sad) { if (drm_cea_sad_is_uncompressed(sad)) { DRM_ERROR("Not supported: tried to get max bitrate for uncompressed format: %u\n", sad->format); return -EINVAL; } return sad->byte2 * 8000; } > +/** > + * 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(const struct cea_sad *sad) > +{ > + if (!drm_cea_sad_is_uncompressed(sad)) { > + DRM_WARN("Unable to get the uncompressed word length for a compressed format: %u\n", > + sad->format); > + return -EINVAL; > + } > + > + switch (sad->byte2) { > + case DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT: > + return 16; > + case DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT: > + return 20; > + case DRM_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 37c420423625..7a939cb95b38 100644 > --- a/include/drm/drm_edid.h > +++ b/include/drm/drm_edid.h > @@ -373,6 +373,18 @@ struct cea_sad { > u8 byte2; > }; > > +#define DRM_CEA_SAD_FREQ_32KHZ BIT(0) > +#define DRM_CEA_SAD_FREQ_44KHZ BIT(1) > +#define DRM_CEA_SAD_FREQ_48KHZ BIT(2) > +#define DRM_CEA_SAD_FREQ_88KHZ BIT(3) > +#define DRM_CEA_SAD_FREQ_96KHZ BIT(4) > +#define DRM_CEA_SAD_FREQ_176KHZ BIT(5) > +#define DRM_CEA_SAD_FREQ_192KHZ BIT(6) > + > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT BIT(0) > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT BIT(1) > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_24BIT BIT(2) > + > struct drm_encoder; > struct drm_connector; > struct drm_connector_state; > @@ -380,6 +392,8 @@ 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(const struct cea_sad *sad); > +int drm_cea_sad_get_uncompressed_word_length(const struct cea_sad *sad); > int drm_av_sync_delay(struct drm_connector *connector, > const struct drm_display_mode *mode); >
On Wed, 2022-05-25 at 14:26 +0200, AngeloGioacchino Del Regno wrote: > Il 23/05/22 12:47, Guillaume Ranquet ha scritto: > > 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 <granquet@baylibre.com> > > --- > > drivers/gpu/drm/drm_edid.c | 74 > > ++++++++++++++++++++++++++++++++++++++ > > include/drm/drm_edid.h | 14 ++++++++ > > 2 files changed, 88 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_edid.c > > b/drivers/gpu/drm/drm_edid.c > > index 561f53831e29..61ef1b1c972c 100644 > > --- a/drivers/gpu/drm/drm_edid.c > > +++ b/drivers/gpu/drm/drm_edid.c > > @@ -4758,6 +4758,80 @@ 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(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_uncompressed(const struct cea_sad *sad) > > +{ > > + switch (sad->format) { > > + case HDMI_AUDIO_CODING_TYPE_STREAM: > > As far as I know, bit 0 is reserved, so HDMI_AUDIO_CODING_TYPE_STREAM > should > never occur here? > Hello Angelo, because we do not know whether "HDMI_AUDIO_CODING_TYPE_STREAM" is compressed, we decide to change this function name to drm_cea_sad_is_pcm to prevent misunderstanding. For this, I will drop case HDMI_AUDIO_CODING_TYPE_STREAM > > + case HDMI_AUDIO_CODING_TYPE_PCM: > > + return true; > > + default: > > + return false; > > + } > > +} > > + > > Also, I think that implementing a > drm_cea_sad_get_compressed_max_bitrate() > function should be pretty straightforward... the spec says that this > is > 8 bits, byte 3 (your byte2) contains the max bitrate divided by 8kHz, > so to extract it, you read byte2 and multiply it by 8000Hz. > > /** > * drm_cea_sad_get_compressed_max_bitrate - Extract maximum bitrate > * @sad: Pointer to the cea_sad structure > * > * Extracts the cea_sad byte2 field and returns the maximum bit rate > * of a compressed audio stream. > * > * Note: This function may only be called for compressed audio. > * > * Return: Maximum bitrate of compressed audio stream in bit/s or > * negative number for error > */ > int drm_cea_sad_get_compressed_max_bitrate(const struct cea_sad *sad) > { > if (drm_cea_sad_is_uncompressed(sad)) { > DRM_ERROR("Not supported: tried to get max bitrate for > uncompressed format: %u\n", > sad->format); > return -EINVAL; > } > > return sad->byte2 * 8000; > } > After sync with Jitao, we think this function is not correct. refer to table of "Short Audio Descriptor" in [1]. [1]:https://en.wikipedia.org/wiki/Extended_Display_Identification_Data BRs, Bo-Chen > > +/** > > + * 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(const struct cea_sad > > *sad) > > +{ > > + if (!drm_cea_sad_is_uncompressed(sad)) { > > + DRM_WARN("Unable to get the uncompressed word length > > for a compressed format: %u\n", > > + sad->format); > > + return -EINVAL; > > + } > > + > > + switch (sad->byte2) { > > + case DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT: > > + return 16; > > + case DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT: > > + return 20; > > + case DRM_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 37c420423625..7a939cb95b38 100644 > > --- a/include/drm/drm_edid.h > > +++ b/include/drm/drm_edid.h > > @@ -373,6 +373,18 @@ struct cea_sad { > > u8 byte2; > > }; > > > > +#define DRM_CEA_SAD_FREQ_32KHZ BIT(0) > > +#define DRM_CEA_SAD_FREQ_44KHZ BIT(1) > > +#define DRM_CEA_SAD_FREQ_48KHZ BIT(2) > > +#define DRM_CEA_SAD_FREQ_88KHZ BIT(3) > > +#define DRM_CEA_SAD_FREQ_96KHZ BIT(4) > > +#define DRM_CEA_SAD_FREQ_176KHZ BIT(5) > > +#define DRM_CEA_SAD_FREQ_192KHZ BIT(6) > > + > > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT BIT(0) > > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT BIT(1) > > +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_24BIT BIT(2) > > + > > struct drm_encoder; > > struct drm_connector; > > struct drm_connector_state; > > @@ -380,6 +392,8 @@ 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(const struct cea_sad *sad); > > +int drm_cea_sad_get_uncompressed_word_length(const struct cea_sad > > *sad); > > int drm_av_sync_delay(struct drm_connector *connector, > > const struct drm_display_mode *mode); > > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 561f53831e29..61ef1b1c972c 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4758,6 +4758,80 @@ 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(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_uncompressed(const struct cea_sad *sad) +{ + switch (sad->format) { + case HDMI_AUDIO_CODING_TYPE_STREAM: + case HDMI_AUDIO_CODING_TYPE_PCM: + return true; + default: + return false; + } +} + +/** + * 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(const struct cea_sad *sad) +{ + if (!drm_cea_sad_is_uncompressed(sad)) { + DRM_WARN("Unable to get the uncompressed word length for a compressed format: %u\n", + sad->format); + return -EINVAL; + } + + switch (sad->byte2) { + case DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT: + return 16; + case DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT: + return 20; + case DRM_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 37c420423625..7a939cb95b38 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -373,6 +373,18 @@ struct cea_sad { u8 byte2; }; +#define DRM_CEA_SAD_FREQ_32KHZ BIT(0) +#define DRM_CEA_SAD_FREQ_44KHZ BIT(1) +#define DRM_CEA_SAD_FREQ_48KHZ BIT(2) +#define DRM_CEA_SAD_FREQ_88KHZ BIT(3) +#define DRM_CEA_SAD_FREQ_96KHZ BIT(4) +#define DRM_CEA_SAD_FREQ_176KHZ BIT(5) +#define DRM_CEA_SAD_FREQ_192KHZ BIT(6) + +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_16BIT BIT(0) +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_20BIT BIT(1) +#define DRM_CEA_SAD_UNCOMPRESSED_WORD_24BIT BIT(2) + struct drm_encoder; struct drm_connector; struct drm_connector_state; @@ -380,6 +392,8 @@ 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(const struct cea_sad *sad); +int drm_cea_sad_get_uncompressed_word_length(const struct cea_sad *sad); int drm_av_sync_delay(struct drm_connector *connector, const struct drm_display_mode *mode);