diff options
| -rw-r--r-- | include/sound/hdaudio.h | 3 | ||||
| -rw-r--r-- | sound/hda/hdac_stream.c | 34 |
2 files changed, 37 insertions, 0 deletions
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index b4fa1c775251..45f944d57982 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -539,6 +539,9 @@ void snd_hdac_stream_sync(struct hdac_stream *azx_dev, bool start, unsigned int streams); void snd_hdac_stream_timecounter_init(struct hdac_stream *azx_dev, unsigned int streams); +int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus, + struct snd_pcm_substream *substream); + /* * macros for easy use */ diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c index ba73a33480b6..820694a2061e 100644 --- a/sound/hda/hdac_stream.c +++ b/sound/hda/hdac_stream.c @@ -13,6 +13,40 @@ #include "trace.h" /** + * snd_hdac_get_stream_stripe_ctl - get stripe control value + * @bus: HD-audio core bus + * @substream: PCM substream + */ +int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus, + struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + unsigned int channels = runtime->channels, + rate = runtime->rate, + bits_per_sample = runtime->sample_bits, + max_sdo_lines, value, sdo_line; + + /* T_AZA_GCAP_NSDO is 1:2 bitfields in GCAP */ + max_sdo_lines = snd_hdac_chip_readl(bus, GCAP) & AZX_GCAP_NSDO; + + /* following is from HD audio spec */ + for (sdo_line = max_sdo_lines; sdo_line > 0; sdo_line >>= 1) { + if (rate > 48000) + value = (channels * bits_per_sample * + (rate / 48000)) / sdo_line; + else + value = (channels * bits_per_sample) / sdo_line; + + if (value >= 8) + break; + } + + /* stripe value: 0 for 1SDO, 1 for 2SDO, 2 for 4SDO lines */ + return sdo_line >> 1; +} +EXPORT_SYMBOL_GPL(snd_hdac_get_stream_stripe_ctl); + +/** * snd_hdac_stream_init - initialize each stream (aka device) * @bus: HD-audio core bus * @azx_dev: HD-audio core stream object to initialize |