[media] tw686x: audio: Implement non-memcpy capture

Now that we've introduced the dma_mode parameter to pick the
DMA operation, let's use it to also select the audio DMA
operation.

When dma_mode != memcpy, the driver will avoid using memcpy
in the audio capture path, and the DMA hardware operation
will act directly on the ALSA buffers.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c
index 91459ab715b24575ed0fdbd3b878bbd7c07db42d..a14d1b07edecfb24b878ac6989689841c282d946 100644 (file)
--- a/drivers/media/pci/tw686x/tw686x-audio.c
+++ b/drivers/media/pci/tw686x/tw686x-audio.c
@@ -62,12 +62,22 @@ void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
                }
                spin_unlock_irqrestore(&ac->lock, flags);
 
+               if (!done || !next)
+                       continue;
+               /*
+                * Checking for a non-nil dma_desc[pb]->virt buffer is
+                * the same as checking for memcpy DMA mode.
+                */
                desc = &ac->dma_descs[pb];
-               if (done && next && desc->virt) {
-                       memcpy(done->virt, desc->virt, desc->size);
-                       ac->ptr = done->dma - ac->buf[0].dma;
-                       snd_pcm_period_elapsed(ac->ss);
+               if (desc->virt) {
+                       memcpy(done->virt, desc->virt,
+                              desc->size);
+               } else {
+                       u32 reg = pb ? ADMA_B_ADDR[ch] : ADMA_P_ADDR[ch];
+                       reg_write(dev, reg, next->dma);
                }
+               ac->ptr = done->dma - ac->buf[0].dma;
+               snd_pcm_period_elapsed(ac->ss);
        }
 }
 
@@ -181,6 +191,12 @@ static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
        ac->curr_bufs[0] = p_buf;
        ac->curr_bufs[1] = b_buf;
        ac->ptr = 0;
+
+       if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY) {
+               reg_write(dev, ADMA_P_ADDR[ac->ch], p_buf->dma);
+               reg_write(dev, ADMA_B_ADDR[ac->ch], b_buf->dma);
+       }
+
        spin_unlock_irqrestore(&ac->lock, flags);
 
        return 0;
@@ -290,6 +306,14 @@ static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
 {
        int pb;
 
+       /*
+        * In the memcpy DMA mode we allocate a consistent buffer
+        * and use it for the DMA capture. Otherwise, DMA
+        * acts on the ALSA buffers as received in pcm_prepare.
+        */
+       if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY)
+               return 0;
+
        for (pb = 0; pb < 2; pb++) {
                u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
                void *virt;