[media] ivtv-alsa, ivtv: Connect ivtv PCM capture stream to ivtv-alsa interface driver

This change hooks up the ivtv PCM capture stream to the ivtv-alsa interface
driver.  This is all that should be needed for basic CX23415/CX23416 PCM
audio capture to be available via ALSA device nodes.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 51 insertions, 0 deletions

diff --git a/drivers/media/pci/ivtv/ivtv-driver.h b/drivers/media/pci/ivtv/ivtv-driver.h
index 1918e7326795..bc309f42c8ed 100644
--- a/drivers/media/pci/ivtv/ivtv-driver.h
+++ b/drivers/media/pci/ivtv/ivtv-driver.h
@@ -259,6 +259,7 @@ struct ivtv_mailbox_data {
 #define IVTV_F_I_DEC_PAUSED        20   /* the decoder is paused */
 #define IVTV_F_I_INITED            21   /* set after first open */
 #define IVTV_F_I_FAILED            22   /* set if first open failed */
+#define IVTV_F_I_WORK_HANDLER_PCM  23   /* there is work to be done for PCM */
 
 /* Event notifications */
 #define IVTV_F_I_EV_DEC_STOPPED    28   /* decoder stopped event */
diff --git a/drivers/media/pci/ivtv/ivtv-irq.c b/drivers/media/pci/ivtv/ivtv-irq.c
index 1b3b9578bf47..19a7c9b990a3 100644
--- a/drivers/media/pci/ivtv/ivtv-irq.c
+++ b/drivers/media/pci/ivtv/ivtv-irq.c
@@ -38,6 +38,34 @@ static const int ivtv_stream_map[] = {
         IVTV_ENC_STREAM_TYPE_VBI,
 };
 
+static void ivtv_pcm_work_handler(struct ivtv *itv)
+{
+        struct ivtv_stream *s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
+        struct ivtv_buffer *buf;
+
+        /* Pass the PCM data to ivtv-alsa */
+
+        while (1) {
+                /*
+                 * Users should not be using both the ALSA and V4L2 PCM audio
+                 * capture interfaces at the same time.  If the user is doing
+                 * this, there maybe a buffer in q_io to grab, use, and put
+                 * back in rotation.
+                 */
+                buf = ivtv_dequeue(s, &s->q_io);
+                if (buf == NULL)
+                        buf = ivtv_dequeue(s, &s->q_full);
+                if (buf == NULL)
+                        break;
+
+                if (buf->readpos < buf->bytesused)
+                        itv->pcm_announce_callback(itv->alsa,
+                                (u8 *)(buf->buf + buf->readpos),
+                                (size_t)(buf->bytesused - buf->readpos));
+
+                ivtv_enqueue(s, buf, &s->q_free);
+        }
+}
 
 static void ivtv_pio_work_handler(struct ivtv *itv)
 {
@@ -83,6 +111,9 @@ void ivtv_irq_work_handler(struct kthread_work *work)
 
         if (test_and_clear_bit(IVTV_F_I_WORK_HANDLER_YUV, &itv->i_flags))
                 ivtv_yuv_work_handler(itv);
+
+        if (test_and_clear_bit(IVTV_F_I_WORK_HANDLER_PCM, &itv->i_flags))
+                ivtv_pcm_work_handler(itv);
 }
 
 /* Determine the required DMA size, setup enough buffers in the predma queue and
@@ -293,7 +324,26 @@ static void dma_post(struct ivtv_stream *s)
                         return;
                 }
         }
+
         ivtv_queue_move(s, &s->q_dma, NULL, &s->q_full, s->q_dma.bytesused);
+
+        if (s->type == IVTV_ENC_STREAM_TYPE_PCM &&
+            itv->pcm_announce_callback != NULL) {
+                /*
+                 * Set up the work handler to pass the data to ivtv-alsa.
+                 *
+                 * We just use q_full and let the work handler race with users
+                 * making ivtv-fileops.c calls on the PCM device node.
+                 *
+                 * Users should not be using both the ALSA and V4L2 PCM audio
+                 * capture interfaces at the same time.  If the user does this,
+                 * fragments of data will just go out each interface as they
+                 * race for PCM data.
+                 */
+                set_bit(IVTV_F_I_WORK_HANDLER_PCM, &itv->i_flags);
+                set_bit(IVTV_F_I_HAVE_WORK, &itv->i_flags);
+        }
+
         if (s->fh)
                 wake_up(&s->waitq);
 }