pcm: file: add infile read support for mmap mode

mmap_begin callback is used to copy data from input file to mmaped
buffer

guard for corner use of api (multiple mmap_begin calls by user) is
introduced to check if next continuous buffer was already overwritten

buffer is overwritten with input file data only in case of stream capture

Signed-off-by: Adam Miartus <amiartus@de.adit-jv.com>
Reviewed-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c
index 8e2c70b12ab1afde9e087508dc4538941a71c6fb..52cc10a9436a14490955bcdf5752c245db81a270 100644 (file)
--- a/src/pcm/pcm_file.c
+++ b/src/pcm/pcm_file.c
@@ -88,6 +88,7 @@ typedef struct {
        size_t buffer_bytes;
        struct wav_fmt wav_header;
        size_t filelen;
+       char ifmmap_overwritten;
 } snd_pcm_file_t;
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -630,6 +631,8 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm,
        const snd_pcm_channel_area_t *areas;
        snd_pcm_sframes_t result;
 
+       file->ifmmap_overwritten = 0;
+
        result = snd_pcm_mmap_begin(file->gen.slave, &areas, &ofs, &siz);
        if (result >= 0) {
                assert(ofs == offset && siz == size);
@@ -640,6 +643,32 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm,
        return result;
 }
 
+static int snd_pcm_file_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas,
+       snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames)
+{
+       snd_pcm_file_t *file = pcm->private_data;
+       snd_pcm_channel_area_t areas_if[pcm->channels];
+       snd_pcm_uframes_t frames_if;
+       void *buffer = NULL;
+       int result;
+
+       result = snd_pcm_mmap_begin(file->gen.slave, areas, offset, frames);
+       if (result < 0)
+               return result;
+
+       if (pcm->stream != SND_PCM_STREAM_CAPTURE)
+               return result;
+
+       /* user may run mmap_begin without mmap_commit multiple times in row */
+       if (file->ifmmap_overwritten)
+               return result;
+       file->ifmmap_overwritten = 1;
+
+       snd_pcm_file_areas_read_infile(pcm, *areas, *offset, *frames);
+
+       return result;
+}
+
 static int snd_pcm_file_hw_free(snd_pcm_t *pcm)
 {
        snd_pcm_file_t *file = pcm->private_data;
@@ -666,6 +695,7 @@ static int snd_pcm_file_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
        file->wbuf_size = slave->buffer_size * 2;
        file->wbuf_size_bytes = snd_pcm_frames_to_bytes(slave, file->wbuf_size);
        file->wbuf_used_bytes = 0;
+       file->ifmmap_overwritten = 0;
        assert(!file->wbuf);
        file->wbuf = malloc(file->wbuf_size_bytes);
        if (file->wbuf == NULL) {
@@ -777,6 +807,7 @@ static const snd_pcm_fast_ops_t snd_pcm_file_fast_ops = {
        .poll_descriptors = snd_pcm_generic_poll_descriptors,
        .poll_revents = snd_pcm_generic_poll_revents,
        .htimestamp = snd_pcm_generic_htimestamp,
+       .mmap_begin = snd_pcm_file_mmap_begin,
 };
 
 /**