| Message ID | 20220712111223.13080-4-rex-bc.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: Add MT8195 DisplayPort driver | expand |
Il 12/07/22 13:12, Bo-Chen Chen ha scritto: > From: Guillaume Ranquet <granquet@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> > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com> > --- > 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
On Thu, 2022-07-14 at 13:12 +0200, AngeloGioacchino Del Regno wrote: > Il 12/07/22 13:12, Bo-Chen Chen ha scritto: > > From: Guillaume Ranquet <granquet@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> > > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com> > > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com> > > --- > > 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 Hello Angelo, I think you are right, in this case, we don't need this help function. I will merge this function into drm_cea_sad_get_uncompressed_word_length() BRs, Bo-Chen
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; + } +} + +/** + * 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_pcm(sad)) { + DRM_WARN("Unable to get the uncompressed word length for 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 c2c43a4af681..779b710aed40 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(const struct edid *edid, struct cea_sad **sads); int drm_edid_to_speaker_allocation(const 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);