ASoC: rsnd: add common DMAEngine method

R-Car Sound driver will support DMA transfer in the future,
then, SSI/SRU/SRC will use it.
Current R-Car can't use soc-dmaengine-pcm.c since its DMAEngine
doesn't support dmaengine_prep_dma_cyclic(),
and SSI needs double plane transfer (which needs special submit) on DMAC.
This patch adds common DMAEngine method for it

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

2 files changed, 164 insertions, 0 deletions

diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
index 420d6df9c3d0..a35706028514 100644
--- a/sound/soc/sh/rcar/core.c
+++ b/sound/soc/sh/rcar/core.c
@@ -174,6 +174,138 @@ void rsnd_mod_init(struct rsnd_priv *priv,
 }
 
 /*
+ *      rsnd_dma functions
+ */
+static void rsnd_dma_continue(struct rsnd_dma *dma)
+{
+        /* push next A or B plane */
+        dma->submit_loop = 1;
+        schedule_work(&dma->work);
+}
+
+void rsnd_dma_start(struct rsnd_dma *dma)
+{
+        /* push both A and B plane*/
+        dma->submit_loop = 2;
+        schedule_work(&dma->work);
+}
+
+void rsnd_dma_stop(struct rsnd_dma *dma)
+{
+        dma->submit_loop = 0;
+        cancel_work_sync(&dma->work);
+        dmaengine_terminate_all(dma->chan);
+}
+
+static void rsnd_dma_complete(void *data)
+{
+        struct rsnd_dma *dma = (struct rsnd_dma *)data;
+        struct rsnd_priv *priv = dma->priv;
+        unsigned long flags;
+
+        rsnd_lock(priv, flags);
+
+        dma->complete(dma);
+
+        if (dma->submit_loop)
+                rsnd_dma_continue(dma);
+
+        rsnd_unlock(priv, flags);
+}
+
+static void rsnd_dma_do_work(struct work_struct *work)
+{
+        struct rsnd_dma *dma = container_of(work, struct rsnd_dma, work);
+        struct rsnd_priv *priv = dma->priv;
+        struct device *dev = rsnd_priv_to_dev(priv);
+        struct dma_async_tx_descriptor *desc;
+        dma_addr_t buf;
+        size_t len;
+        int i;
+
+        for (i = 0; i < dma->submit_loop; i++) {
+
+                if (dma->inquiry(dma, &buf, &len) < 0)
+                        return;
+
+                desc = dmaengine_prep_slave_single(
+                        dma->chan, buf, len, dma->dir,
+                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+                if (!desc) {
+                        dev_err(dev, "dmaengine_prep_slave_sg() fail\n");
+                        return;
+                }
+
+                desc->callback          = rsnd_dma_complete;
+                desc->callback_param    = dma;
+
+                if (dmaengine_submit(desc) < 0) {
+                        dev_err(dev, "dmaengine_submit() fail\n");
+                        return;
+                }
+
+        }
+
+        dma_async_issue_pending(dma->chan);
+}
+
+int rsnd_dma_available(struct rsnd_dma *dma)
+{
+        return !!dma->chan;
+}
+
+static bool rsnd_dma_filter(struct dma_chan *chan, void *param)
+{
+        chan->private = param;
+
+        return true;
+}
+
+int rsnd_dma_init(struct rsnd_priv *priv, struct rsnd_dma *dma,
+                  int is_play, int id,
+                  int (*inquiry)(struct rsnd_dma *dma,
+                                  dma_addr_t *buf, int *len),
+                  int (*complete)(struct rsnd_dma *dma))
+{
+        struct device *dev = rsnd_priv_to_dev(priv);
+        dma_cap_mask_t mask;
+
+        if (dma->chan) {
+                dev_err(dev, "it already has dma channel\n");
+                return -EIO;
+        }
+
+        dma_cap_zero(mask);
+        dma_cap_set(DMA_SLAVE, mask);
+
+        dma->slave.shdma_slave.slave_id = id;
+
+        dma->chan = dma_request_channel(mask, rsnd_dma_filter,
+                                        &dma->slave.shdma_slave);
+        if (!dma->chan) {
+                dev_err(dev, "can't get dma channel\n");
+                return -EIO;
+        }
+
+        dma->dir = is_play ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+        dma->priv = priv;
+        dma->inquiry = inquiry;
+        dma->complete = complete;
+        INIT_WORK(&dma->work, rsnd_dma_do_work);
+
+        return 0;
+}
+
+void  rsnd_dma_quit(struct rsnd_priv *priv,
+                    struct rsnd_dma *dma)
+{
+        if (dma->chan)
+                dma_release_channel(dma->chan);
+
+        dma->chan = NULL;
+}
+
+/*
  *      rsnd_dai functions
  */
 #define rsnd_dai_call(rdai, io, fn)                     \
diff --git a/sound/soc/sh/rcar/rsnd.h b/sound/soc/sh/rcar/rsnd.h
index 9243e387104c..15dccd598960 100644
--- a/sound/soc/sh/rcar/rsnd.h
+++ b/sound/soc/sh/rcar/rsnd.h
@@ -13,9 +13,12 @@
 
 #include <linux/clk.h>
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/sh_dma.h>
+#include <linux/workqueue.h>
 #include <sound/rcar_snd.h>
 #include <sound/soc.h>
 #include <sound/pcm_params.h>
@@ -79,6 +82,32 @@ void rsnd_bset(struct rsnd_priv *priv, struct rsnd_mod *mod, enum rsnd_reg reg,
                     u32 mask, u32 data);
 
 /*
+ *      R-Car DMA
+ */
+struct rsnd_dma {
+        struct rsnd_priv        *priv;
+        struct sh_dmae_slave    slave;
+        struct work_struct      work;
+        struct dma_chan         *chan;
+        enum dma_data_direction dir;
+        int (*inquiry)(struct rsnd_dma *dma, dma_addr_t *buf, int *len);
+        int (*complete)(struct rsnd_dma *dma);
+
+        int submit_loop;
+};
+
+void rsnd_dma_start(struct rsnd_dma *dma);
+void rsnd_dma_stop(struct rsnd_dma *dma);
+int rsnd_dma_available(struct rsnd_dma *dma);
+int rsnd_dma_init(struct rsnd_priv *priv, struct rsnd_dma *dma,
+        int is_play, int id,
+        int (*inquiry)(struct rsnd_dma *dma, dma_addr_t *buf, int *len),
+        int (*complete)(struct rsnd_dma *dma));
+void  rsnd_dma_quit(struct rsnd_priv *priv,
+                    struct rsnd_dma *dma);
+
+
+/*
  *      R-Car sound mod
  */
 
@@ -103,9 +132,12 @@ struct rsnd_mod {
         struct rsnd_priv *priv;
         struct rsnd_mod_ops *ops;
         struct list_head list; /* connect to rsnd_dai playback/capture */
+        struct rsnd_dma dma;
 };
 
 #define rsnd_mod_to_priv(mod) ((mod)->priv)
+#define rsnd_mod_to_dma(mod) (&(mod)->dma)
+#define rsnd_dma_to_mod(_dma) container_of((_dma), struct rsnd_mod, dma)
 #define rsnd_mod_id(mod) ((mod)->id)
 #define for_each_rsnd_mod(pos, n, io)   \
         list_for_each_entry_safe(pos, n, &(io)->head, list)