DMA: PL330: Add DMA_CYCLIC capability

This patch adds DMA_CYCLIC capability that is used for audio driver.
DMA driver activated with it reuses the dma requests that were submitted
through tx_submit().

Signed-off-by: Boojin Kim <boojin.kim@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 83 insertions, 1 deletions

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 59943ec1e74a..621134fdba4c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -75,6 +75,9 @@ struct dma_pl330_chan {
         int burst_sz; /* the peripheral fifo width */
         int burst_len; /* the number of burst */
         dma_addr_t fifo_addr;
+
+        /* for cyclic capability */
+        bool cyclic;
 };
 
 struct dma_pl330_dmac {
@@ -161,6 +164,31 @@ static inline void free_desc_list(struct list_head *list)
         spin_unlock_irqrestore(&pdmac->pool_lock, flags);
 }
 
+static inline void handle_cyclic_desc_list(struct list_head *list)
+{
+        struct dma_pl330_desc *desc;
+        struct dma_pl330_chan *pch;
+        unsigned long flags;
+
+        if (list_empty(list))
+                return;
+
+        list_for_each_entry(desc, list, node) {
+                dma_async_tx_callback callback;
+
+                /* Change status to reload it */
+                desc->status = PREP;
+                pch = desc->pchan;
+                callback = desc->txd.callback;
+                if (callback)
+                        callback(desc->txd.callback_param);
+        }
+
+        spin_lock_irqsave(&pch->lock, flags);
+        list_splice_tail_init(list, &pch->work_list);
+        spin_unlock_irqrestore(&pch->lock, flags);
+}
+
 static inline void fill_queue(struct dma_pl330_chan *pch)
 {
         struct dma_pl330_desc *desc;
@@ -214,7 +242,10 @@ static void pl330_tasklet(unsigned long data)
 
         spin_unlock_irqrestore(&pch->lock, flags);
 
-        free_desc_list(&list);
+        if (pch->cyclic)
+                handle_cyclic_desc_list(&list);
+        else
+                free_desc_list(&list);
 }
 
 static void dma_pl330_rqcb(void *token, enum pl330_op_err err)
@@ -245,6 +276,7 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)
         spin_lock_irqsave(&pch->lock, flags);
 
         pch->completed = chan->cookie = 1;
+        pch->cyclic = false;
 
         pch->pl330_chid = pl330_request_channel(&pdmac->pif);
         if (!pch->pl330_chid) {
@@ -324,6 +356,9 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
         pl330_release_channel(pch->pl330_chid);
         pch->pl330_chid = NULL;
 
+        if (pch->cyclic)
+                list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool);
+
         spin_unlock_irqrestore(&pch->lock, flags);
 }
 
@@ -560,6 +595,51 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
         return burst_len;
 }
 
+static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
+                struct dma_chan *chan, dma_addr_t dma_addr, size_t len,
+                size_t period_len, enum dma_data_direction direction)
+{
+        struct dma_pl330_desc *desc;
+        struct dma_pl330_chan *pch = to_pchan(chan);
+        dma_addr_t dst;
+        dma_addr_t src;
+
+        desc = pl330_get_desc(pch);
+        if (!desc) {
+                dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
+                        __func__, __LINE__);
+                return NULL;
+        }
+
+        switch (direction) {
+        case DMA_TO_DEVICE:
+                desc->rqcfg.src_inc = 1;
+                desc->rqcfg.dst_inc = 0;
+                src = dma_addr;
+                dst = pch->fifo_addr;
+                break;
+        case DMA_FROM_DEVICE:
+                desc->rqcfg.src_inc = 0;
+                desc->rqcfg.dst_inc = 1;
+                src = pch->fifo_addr;
+                dst = dma_addr;
+                break;
+        default:
+                dev_err(pch->dmac->pif.dev, "%s:%d Invalid dma direction\n",
+                __func__, __LINE__);
+                return NULL;
+        }
+
+        desc->rqcfg.brst_size = pch->burst_sz;
+        desc->rqcfg.brst_len = 1;
+
+        pch->cyclic = true;
+
+        fill_px(&desc->px, dst, src, period_len);
+
+        return &desc->txd;
+}
+
 static struct dma_async_tx_descriptor *
 pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
                 dma_addr_t src, size_t len, unsigned long flags)
@@ -791,6 +871,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
                         case MEMTODEV:
                         case DEVTOMEM:
                                 dma_cap_set(DMA_SLAVE, pd->cap_mask);
+                                dma_cap_set(DMA_CYCLIC, pd->cap_mask);
                                 break;
                         default:
                                 dev_err(&adev->dev, "DEVTODEV Not Supported\n");
@@ -819,6 +900,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
         pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
         pd->device_free_chan_resources = pl330_free_chan_resources;
         pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy;
+        pd->device_prep_dma_cyclic = pl330_prep_dma_cyclic;
         pd->device_tx_status = pl330_tx_status;
         pd->device_prep_slave_sg = pl330_prep_slave_sg;
         pd->device_control = pl330_control;