ALSA: pcm: More kerneldoc updates

Add proper kerneldoc comments to the exported functions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 153 insertions, 7 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 5c3310d7d4b8..f78a5722f5cc 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -533,6 +533,12 @@ snd_pcm_debug_name(struct snd_pcm_substream *substream, char *buf, size_t size)
  *  PCM library
  */
 
+/**
+ * snd_pcm_stream_linked - Check whether the substream is linked with others
+ * @substream: substream to check
+ *
+ * Returns true if the given substream is being linked with others.
+ */
 static inline int snd_pcm_stream_linked(struct snd_pcm_substream *substream)
 {
         return substream->group != &substream->self_group;
@@ -543,6 +549,16 @@ void snd_pcm_stream_unlock(struct snd_pcm_substream *substream);
 void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream);
 void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream);
 unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream);
+
+/**
+ * snd_pcm_stream_lock_irqsave - Lock the PCM stream
+ * @substream: PCM substream
+ * @flags: irq flags
+ *
+ * This locks the PCM stream like snd_pcm_stream_lock() but with the local
+ * IRQ (only when nonatomic is false).  In nonatomic case, this is identical
+ * as snd_pcm_stream_lock().
+ */
 #define snd_pcm_stream_lock_irqsave(substream, flags)            \
         do {                                                     \
                 typecheck(unsigned long, flags);                 \
@@ -551,9 +567,25 @@ unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream);
 void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
                                       unsigned long flags);
 
+/**
+ * snd_pcm_group_for_each_entry - iterate over the linked substreams
+ * @s: the iterator
+ * @substream: the substream
+ *
+ * Iterate over the all linked substreams to the given @substream.
+ * When @substream isn't linked with any others, this gives returns @substream
+ * itself once.
+ */
 #define snd_pcm_group_for_each_entry(s, substream) \
         list_for_each_entry(s, &substream->group->substreams, link_list)
 
+/**
+ * snd_pcm_running - Check whether the substream is in a running state
+ * @substream: substream to check
+ *
+ * Returns true if the given substream is in the state RUNNING, or in the
+ * state DRAINING for playback.
+ */
 static inline int snd_pcm_running(struct snd_pcm_substream *substream)
 {
         return (substream->runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
@@ -561,45 +593,81 @@ static inline int snd_pcm_running(struct snd_pcm_substream *substream)
                  substream->stream == SNDRV_PCM_STREAM_PLAYBACK));
 }
 
+/**
+ * bytes_to_samples - Unit conversion of the size from bytes to samples
+ * @runtime: PCM runtime instance
+ * @size: size in bytes
+ */
 static inline ssize_t bytes_to_samples(struct snd_pcm_runtime *runtime, ssize_t size)
 {
         return size * 8 / runtime->sample_bits;
 }
 
+/**
+ * bytes_to_frames - Unit conversion of the size from bytes to frames
+ * @runtime: PCM runtime instance
+ * @size: size in bytes
+ */
 static inline snd_pcm_sframes_t bytes_to_frames(struct snd_pcm_runtime *runtime, ssize_t size)
 {
         return size * 8 / runtime->frame_bits;
 }
 
+/**
+ * samples_to_bytes - Unit conversion of the size from samples to bytes
+ * @runtime: PCM runtime instance
+ * @size: size in samples
+ */
 static inline ssize_t samples_to_bytes(struct snd_pcm_runtime *runtime, ssize_t size)
 {
         return size * runtime->sample_bits / 8;
 }
 
+/**
+ * frames_to_bytes - Unit conversion of the size from frames to bytes
+ * @runtime: PCM runtime instance
+ * @size: size in frames
+ */
 static inline ssize_t frames_to_bytes(struct snd_pcm_runtime *runtime, snd_pcm_sframes_t size)
 {
         return size * runtime->frame_bits / 8;
 }
 
+/**
+ * frame_aligned - Check whether the byte size is aligned to frames
+ * @runtime: PCM runtime instance
+ * @bytes: size in bytes
+ */
 static inline int frame_aligned(struct snd_pcm_runtime *runtime, ssize_t bytes)
 {
         return bytes % runtime->byte_align == 0;
 }
 
+/**
+ * snd_pcm_lib_buffer_bytes - Get the buffer size of the current PCM in bytes
+ * @substream: PCM substream
+ */
 static inline size_t snd_pcm_lib_buffer_bytes(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
         return frames_to_bytes(runtime, runtime->buffer_size);
 }
 
+/**
+ * snd_pcm_lib_period_bytes - Get the period size of the current PCM in bytes
+ * @substream: PCM substream
+ */
 static inline size_t snd_pcm_lib_period_bytes(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
         return frames_to_bytes(runtime, runtime->period_size);
 }
 
-/*
- *  result is: 0 ... (boundary - 1)
+/**
+ * snd_pcm_playback_avail - Get the available (writable) space for playback
+ * @runtime: PCM runtime instance
+ *
+ * Result is between 0 ... (boundary - 1)
  */
 static inline snd_pcm_uframes_t snd_pcm_playback_avail(struct snd_pcm_runtime *runtime)
 {
@@ -611,8 +679,11 @@ static inline snd_pcm_uframes_t snd_pcm_playback_avail(struct snd_pcm_runtime *r
         return avail;
 }
 
-/*
- *  result is: 0 ... (boundary - 1)
+/**
+ * snd_pcm_playback_avail - Get the available (readable) space for capture
+ * @runtime: PCM runtime instance
+ *
+ * Result is between 0 ... (boundary - 1)
  */
 static inline snd_pcm_uframes_t snd_pcm_capture_avail(struct snd_pcm_runtime *runtime)
 {
@@ -622,11 +693,19 @@ static inline snd_pcm_uframes_t snd_pcm_capture_avail(struct snd_pcm_runtime *ru
         return avail;
 }
 
+/**
+ * snd_pcm_playback_hw_avail - Get the queued space for playback
+ * @runtime: PCM runtime instance
+ */
 static inline snd_pcm_sframes_t snd_pcm_playback_hw_avail(struct snd_pcm_runtime *runtime)
 {
         return runtime->buffer_size - snd_pcm_playback_avail(runtime);
 }
 
+/**
+ * snd_pcm_capture_hw_avail - Get the free space for capture
+ * @runtime: PCM runtime instance
+ */
 static inline snd_pcm_sframes_t snd_pcm_capture_hw_avail(struct snd_pcm_runtime *runtime)
 {
         return runtime->buffer_size - snd_pcm_capture_avail(runtime);
@@ -706,6 +785,20 @@ static inline int snd_pcm_capture_empty(struct snd_pcm_substream *substream)
         return snd_pcm_capture_avail(runtime) == 0;
 }
 
+/**
+ * snd_pcm_trigger_done - Mark the master substream
+ * @substream: the pcm substream instance
+ * @master: the linked master substream
+ *
+ * When multiple substreams of the same card are linked and the hardware
+ * supports the single-shot operation, the driver calls this in the loop
+ * in snd_pcm_group_for_each_entry() for marking the substream as "done".
+ * Then most of trigger operations are performed only to the given master
+ * substream.
+ *
+ * The trigger_master mark is cleared at timestamp updates at the end
+ * of trigger operations.
+ */
 static inline void snd_pcm_trigger_done(struct snd_pcm_substream *substream, 
                                         struct snd_pcm_substream *master)
 {
@@ -881,6 +974,14 @@ unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit);
 unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
                                          unsigned int rates_b);
 
+/**
+ * snd_pcm_set_runtime_buffer - Set the PCM runtime buffer
+ * @substream: PCM substream to set
+ * @bufp: the buffer information, NULL to clear
+ *
+ * Copy the buffer information to runtime->dma_buffer when @bufp is non-NULL.
+ * Otherwise it clears the current buffer information.
+ */
 static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream,
                                               struct snd_dma_buffer *bufp)
 {
@@ -906,6 +1007,11 @@ void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream);
 void snd_pcm_timer_init(struct snd_pcm_substream *substream);
 void snd_pcm_timer_done(struct snd_pcm_substream *substream);
 
+/**
+ * snd_pcm_gettime - Fill the timespec depending on the timestamp mode
+ * @runtime: PCM runtime instance
+ * @tv: timespec to fill
+ */
 static inline void snd_pcm_gettime(struct snd_pcm_runtime *runtime,
                                    struct timespec *tv)
 {
@@ -997,18 +1103,35 @@ struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream,
 #define snd_pcm_sgbuf_ops_page  NULL
 #endif /* SND_DMA_SGBUF */
 
+/**
+ * snd_pcm_sgbuf_get_addr - Get the DMA address at the corresponding offset
+ * @substream: PCM substream
+ * @ofs: byte offset
+ */
 static inline dma_addr_t
 snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)
 {
         return snd_sgbuf_get_addr(snd_pcm_get_dma_buf(substream), ofs);
 }
 
+/**
+ * snd_pcm_sgbuf_get_ptr - Get the virtual address at the corresponding offset
+ * @substream: PCM substream
+ * @ofs: byte offset
+ */
 static inline void *
 snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)
 {
         return snd_sgbuf_get_ptr(snd_pcm_get_dma_buf(substream), ofs);
 }
 
+/**
+ * snd_pcm_sgbuf_chunk_size - Compute the max size that fits within the contig.
+ * page from the given size
+ * @substream: PCM substream
+ * @ofs: byte offset
+ * @size: byte size to examine
+ */
 static inline unsigned int
 snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
                              unsigned int ofs, unsigned int size)
@@ -1016,13 +1139,24 @@ snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
         return snd_sgbuf_get_chunk_size(snd_pcm_get_dma_buf(substream), ofs, size);
 }
 
-/* handle mmap counter - PCM mmap callback should handle this counter properly */
+/**
+ * snd_pcm_mmap_data_open - increase the mmap counter
+ * @area: VMA
+ *
+ * PCM mmap callback should handle this counter properly
+ */
 static inline void snd_pcm_mmap_data_open(struct vm_area_struct *area)
 {
         struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
         atomic_inc(&substream->mmap_count);
 }
 
+/**
+ * snd_pcm_mmap_data_close - decrease the mmap counter
+ * @area: VMA
+ *
+ * PCM mmap callback should handle this counter properly
+ */
 static inline void snd_pcm_mmap_data_close(struct vm_area_struct *area)
 {
         struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
@@ -1042,6 +1176,11 @@ int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream, struct vm_area_s
 
 #define snd_pcm_lib_mmap_vmalloc NULL
 
+/**
+ * snd_pcm_limit_isa_dma_size - Get the max size fitting with ISA DMA transfer
+ * @dma: DMA number
+ * @max: pointer to store the max size
+ */
 static inline void snd_pcm_limit_isa_dma_size(int dma, size_t *max)
 {
         *max = dma < 4 ? 64 * 1024 : 128 * 1024;
@@ -1094,7 +1233,11 @@ struct snd_pcm_chmap {
         void *private_data;     /* optional: private data pointer */
 };
 
-/* get the PCM substream assigned to the given chmap info */
+/**
+ * snd_pcm_chmap_substream - get the PCM substream assigned to the given chmap info
+ * @info: chmap information
+ * @idx: the substream number index
+ */
 static inline struct snd_pcm_substream *
 snd_pcm_chmap_substream(struct snd_pcm_chmap *info, unsigned int idx)
 {
@@ -1121,7 +1264,10 @@ int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
                            unsigned long private_value,
                            struct snd_pcm_chmap **info_ret);
 
-/* Strong-typed conversion of pcm_format to bitwise */
+/**
+ * pcm_format_to_bits - Strong-typed conversion of pcm_format to bitwise
+ * @pcm_format: PCM format
+ */
 static inline u64 pcm_format_to_bits(snd_pcm_format_t pcm_format)
 {
         return 1ULL << (__force int) pcm_format;