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author | Takashi Iwai <tiwai@suse.de> | 2014-10-30 14:02:50 (GMT) |
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committer | Takashi Iwai <tiwai@suse.de> | 2014-10-30 14:42:27 (GMT) |
commit | 30b771cf8c3120c5c946811ecc5a9b87a34003a2 (patch) | |
tree | 3883bd7d092e5a822759604e3e0b9ead40345334 /sound/core/pcm_native.c | |
parent | f213d8f79a3928eaa2e2936f8ab40761aac04b95 (diff) | |
download | linux-30b771cf8c3120c5c946811ecc5a9b87a34003a2.tar.xz |
ALSA: pcm: More kerneldoc updates
Add proper kerneldoc comments to the exported functions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/pcm_native.c')
-rw-r--r-- | sound/core/pcm_native.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 2f7ad10..4d5795d 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -74,6 +74,14 @@ static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream); static DEFINE_RWLOCK(snd_pcm_link_rwlock); static DECLARE_RWSEM(snd_pcm_link_rwsem); +/** + * snd_pcm_stream_lock - Lock the PCM stream + * @substream: PCM substream + * + * This locks the PCM stream's spinlock or mutex depending on the nonatomic + * flag of the given substream. This also takes the global link rw lock + * (or rw sem), too, for avoiding the race with linked streams. + */ void snd_pcm_stream_lock(struct snd_pcm_substream *substream) { if (substream->pcm->nonatomic) { @@ -86,6 +94,12 @@ void snd_pcm_stream_lock(struct snd_pcm_substream *substream) } EXPORT_SYMBOL_GPL(snd_pcm_stream_lock); +/** + * snd_pcm_stream_lock - Unlock the PCM stream + * @substream: PCM substream + * + * This unlocks the PCM stream that has been locked via snd_pcm_stream_lock(). + */ void snd_pcm_stream_unlock(struct snd_pcm_substream *substream) { if (substream->pcm->nonatomic) { @@ -98,6 +112,14 @@ void snd_pcm_stream_unlock(struct snd_pcm_substream *substream) } EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock); +/** + * snd_pcm_stream_lock_irq - Lock the PCM stream + * @substream: PCM substream + * + * This locks the PCM stream like snd_pcm_stream_lock() and disables the local + * IRQ (only when nonatomic is false). In nonatomic case, this is identical + * as snd_pcm_stream_lock(). + */ void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream) { if (!substream->pcm->nonatomic) @@ -106,6 +128,12 @@ void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream) } EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq); +/** + * snd_pcm_stream_unlock_irq - Unlock the PCM stream + * @substream: PCM substream + * + * This is a counter-part of snd_pcm_stream_lock_irq(). + */ void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream) { snd_pcm_stream_unlock(substream); @@ -124,6 +152,13 @@ unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream) } EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave); +/** + * snd_pcm_stream_unlock_irqrestore - Unlock the PCM stream + * @substream: PCM substream + * @flags: irq flags + * + * This is a counter-part of snd_pcm_stream_lock_irqsave(). + */ void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream, unsigned long flags) { @@ -3312,6 +3347,15 @@ static const struct vm_operations_struct snd_pcm_vm_ops_data_fault = { /* * mmap the DMA buffer on RAM */ + +/** + * snd_pcm_lib_default_mmap - Default PCM data mmap function + * @substream: PCM substream + * @area: VMA + * + * This is the default mmap handler for PCM data. When mmap pcm_ops is NULL, + * this function is invoked implicitly. + */ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *area) { @@ -3343,6 +3387,15 @@ EXPORT_SYMBOL_GPL(snd_pcm_lib_default_mmap); * mmap the DMA buffer on I/O memory area */ #if SNDRV_PCM_INFO_MMAP_IOMEM +/** + * snd_pcm_lib_mmap_iomem - Default PCM data mmap function for I/O mem + * @substream: PCM substream + * @area: VMA + * + * When your hardware uses the iomapped pages as the hardware buffer and + * wants to mmap it, pass this function as mmap pcm_ops. Note that this + * is supposed to work only on limited architectures. + */ int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream, struct vm_area_struct *area) { |