+struct snd_compr_runtime {
- snd_pcm_state_t state;
- struct snd_compr_ops *ops;
- void *buffer;
- size_t buffer_size;
- size_t fragment_size;
- unsigned int fragments;
- size_t hw_pointer;
- size_t app_pointer;
- size_t bytes_written;
Is it the bytes written to the ring buffer?
- size_t bytes_copied;
Is it the bytes copied by the DSP from ring buffer?
- wait_queue_head_t sleep;
+};
+/** +mandatory */ struct snd_compr_ops {
- int (*open)(struct snd_compr_stream *stream);
- int (*free)(struct snd_compr_stream *stream);
- int (*set_params)(struct snd_compr_stream *stream,
struct snd_compr_params *params);- int (*get_params)(struct snd_compr_stream *stream,
struct snd_compr_params *params);- int (*trigger)(struct snd_compr_stream *stream, int cmd);
- int (*pointer)(struct snd_compr_stream *stream,
struct snd_compr_tstamp *tstamp);- int (*copy)(struct snd_compr_stream *stream, const char __user *buf,
size_t count);- int (*mmap)(struct snd_compr_stream *stream,
struct vm_area_struct *vma);- int (*ack)(struct snd_compr_stream *stream, size_t bytes);
- int (*get_caps) (struct snd_compr_stream *stream,
struct snd_compr_caps *caps);- int (*get_codec_caps) (struct snd_compr_stream *stream,
struct snd_compr_codec_caps *codec); };
Documentation (PATCH 1/6) talks about get_codecs which is missing? Fix the documentation or add the API?
- */
+struct snd_compr {
- const char *name;
- unsigned int pb;
- unsigned int cap;
Can we use a single variable if it just
- struct device *dev;
- struct snd_compr_ops *ops;
- void *private_data;
- struct snd_card *card;
- struct mutex lock;
- int device;
+};
- For recording: we may want to know when a frame is available or when
- at least one frame is available for userspace, a different
- snd_compress_frame_elapsed() callback should be used */ void
+snd_compr_fragment_elapsed(struct snd_compr_stream *stream); void +snd_compr_frame_elapsed(struct snd_compr_stream *stream);
What is the use of this API? DSP could send only fragment elapsed. Not sure we need to received interrupt for every frame. The system will be flooded with interrupts.
+/**
- struct snd_compr_tstamp: timestamp descriptor
- @copied_bytes: Number of bytes offset in ring buffer to DSP
- @copied_total: Total number of bytes copied from ring buffer to DSP
- @decoded: Frames decoded by DSP
- @rendered: Frames rendered by DSP into a mixer or an audio output
- @sampling_rate: sampling rate of audio */ struct snd_compr_tstamp {
- size_t copied_bytes;
- size_t copied_total;
- size_t decoded;
- size_t rendered;
- __u32 sampling_rate;
Is it possible to track the rendering sampling rate in the driver itself?
+struct snd_compr_caps {
- __u32 num_codecs;
- __u32 min_fragment_size;
- __u32 max_fragment_size;
- __u32 min_fragments;
- __u32 max_fragments;
- __u32 codecs[MAX_NUM_CODECS];
- __u32 reserved[11];
Can we add number of compress streams supported in DSP?
+};
+/**
- struct snd_compr_codec_caps: query capability of codec
- @codec: codec for which capability is queried
- @num_descriptors: number of codec descriptors
- @descriptor: array of codec capability descriptor */ struct
+snd_compr_codec_caps {
- __u32 codec;
- __u32 num_descriptors;
- struct snd_codec_desc descriptor[MAX_NUM_CODEC_DESCRIPTORS];
+};