ASoC: rsnd: use dma_sync_single_for_xxx() for IOMMU

IOMMU needs DMA mapping function to use it. One solution is that
we can use DMA mapped dev on snd_pcm_lib_preallocate_pages_for_all()
for SNDRV_DMA_TYPE_DEV. But pcm_new and dma map timing are mismatched.
Thus, this patch uses SNDRV_DMA_TYPE_CONTINUOUS for pcm_new,
and use dma_sync_single_for_xxx() for each transfer.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 82 insertions, 6 deletions

diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
index 9ffa29941ceb..912dc62ff9c7 100644
--- a/sound/soc/sh/rcar/core.c
+++ b/sound/soc/sh/rcar/core.c
@@ -1126,8 +1126,8 @@ static int rsnd_pcm_new(struct snd_soc_pcm_runtime *rtd)
 
         return snd_pcm_lib_preallocate_pages_for_all(
                 rtd->pcm,
-                SNDRV_DMA_TYPE_DEV,
-                rtd->card->snd_card->dev,
+                SNDRV_DMA_TYPE_CONTINUOUS,
+                snd_dma_continuous_data(GFP_KERNEL),
                 PREALLOC_BUFFER, PREALLOC_BUFFER_MAX);
 }
 
diff --git a/sound/soc/sh/rcar/dma.c b/sound/soc/sh/rcar/dma.c
index 3c663a5cfe8b..1f405c833867 100644
--- a/sound/soc/sh/rcar/dma.c
+++ b/sound/soc/sh/rcar/dma.c
@@ -25,6 +25,10 @@
 
 struct rsnd_dmaen {
         struct dma_chan         *chan;
+        dma_addr_t              dma_buf;
+        unsigned int            dma_len;
+        unsigned int            dma_period;
+        unsigned int            dma_cnt;
 };
 
 struct rsnd_dmapp {
@@ -58,10 +62,38 @@ struct rsnd_dma_ctrl {
 /*
  *              Audio DMAC
  */
+#define rsnd_dmaen_sync(dmaen, io, i)   __rsnd_dmaen_sync(dmaen, io, i, 1)
+#define rsnd_dmaen_unsync(dmaen, io, i) __rsnd_dmaen_sync(dmaen, io, i, 0)
+static void __rsnd_dmaen_sync(struct rsnd_dmaen *dmaen, struct rsnd_dai_stream *io,
+                              int i, int sync)
+{
+        struct device *dev = dmaen->chan->device->dev;
+        enum dma_data_direction dir;
+        int is_play = rsnd_io_is_play(io);
+        dma_addr_t buf;
+        int len, max;
+        size_t period;
+
+        len     = dmaen->dma_len;
+        period  = dmaen->dma_period;
+        max     = len / period;
+        i       = i % max;
+        buf     = dmaen->dma_buf + (period * i);
+
+        dir = is_play ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+        if (sync)
+                dma_sync_single_for_device(dev, buf, period, dir);
+        else
+                dma_sync_single_for_cpu(dev, buf, period, dir);
+}
+
 static void __rsnd_dmaen_complete(struct rsnd_mod *mod,
                                   struct rsnd_dai_stream *io)
 {
         struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
+        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
+        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
         bool elapsed = false;
         unsigned long flags;
 
@@ -78,9 +110,22 @@ static void __rsnd_dmaen_complete(struct rsnd_mod *mod,
          */
         spin_lock_irqsave(&priv->lock, flags);
 
-        if (rsnd_io_is_working(io))
+        if (rsnd_io_is_working(io)) {
+                rsnd_dmaen_unsync(dmaen, io, dmaen->dma_cnt);
+
+                /*
+                 * Next period is already started.
+                 * Let's sync Next Next period
+                 * see
+                 *      rsnd_dmaen_start()
+                 */
+                rsnd_dmaen_sync(dmaen, io, dmaen->dma_cnt + 2);
+
                 elapsed = rsnd_dai_pointer_update(io, io->byte_per_period);
 
+                dmaen->dma_cnt++;
+        }
+
         spin_unlock_irqrestore(&priv->lock, flags);
 
         if (elapsed)
@@ -116,7 +161,12 @@ static int rsnd_dmaen_stop(struct rsnd_mod *mod,
         struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
 
         if (dmaen->chan) {
+                int is_play = rsnd_io_is_play(io);
+
                 dmaengine_terminate_all(dmaen->chan);
+                dma_unmap_single(dmaen->chan->device->dev,
+                                 dmaen->dma_buf, dmaen->dma_len,
+                                 is_play ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
         }
 
         return 0;
@@ -184,7 +234,11 @@ static int rsnd_dmaen_start(struct rsnd_mod *mod,
         struct device *dev = rsnd_priv_to_dev(priv);
         struct dma_async_tx_descriptor *desc;
         struct dma_slave_config cfg = {};
+        dma_addr_t buf;
+        size_t len;
+        size_t period;
         int is_play = rsnd_io_is_play(io);
+        int i;
         int ret;
 
         cfg.direction   = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
@@ -201,10 +255,19 @@ static int rsnd_dmaen_start(struct rsnd_mod *mod,
         if (ret < 0)
                 return ret;
 
+        len     = snd_pcm_lib_buffer_bytes(substream);
+        period  = snd_pcm_lib_period_bytes(substream);
+        buf     = dma_map_single(dmaen->chan->device->dev,
+                                 substream->runtime->dma_area,
+                                 len,
+                                 is_play ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+        if (dma_mapping_error(dmaen->chan->device->dev, buf)) {
+                dev_err(dev, "dma map failed\n");
+                return -EIO;
+        }
+
         desc = dmaengine_prep_dma_cyclic(dmaen->chan,
-                                         substream->runtime->dma_addr,
-                                         snd_pcm_lib_buffer_bytes(substream),
-                                         snd_pcm_lib_period_bytes(substream),
+                                         buf, len, period,
                                          is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
                                          DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 
@@ -216,6 +279,19 @@ static int rsnd_dmaen_start(struct rsnd_mod *mod,
         desc->callback          = rsnd_dmaen_complete;
         desc->callback_param    = rsnd_mod_get(dma);
 
+        dmaen->dma_buf          = buf;
+        dmaen->dma_len          = len;
+        dmaen->dma_period       = period;
+        dmaen->dma_cnt          = 0;
+
+        /*
+         * synchronize this and next period
+         * see
+         *      __rsnd_dmaen_complete()
+         */
+        for (i = 0; i < 2; i++)
+                rsnd_dmaen_sync(dmaen, io, i);
+
         if (dmaengine_submit(desc) < 0) {
                 dev_err(dev, "dmaengine_submit() fail\n");
                 return -EIO;