dmaengine: omap-dma: Support for slave devices with data port window

Based on the src/dst_port_window_size - if it is set - configure the DMA
channel to use double indexing in order to be able to loop within the
address window.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 15eb802..ac68666 100644 (file)
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -166,6 +166,9 @@ enum {
        CSDP_DST_BURST_16       = 1 << 14,
        CSDP_DST_BURST_32       = 2 << 14,
        CSDP_DST_BURST_64       = 3 << 14,
+       CSDP_WRITE_NON_POSTED   = 0 << 16,
+       CSDP_WRITE_POSTED       = 1 << 16,
+       CSDP_WRITE_LAST_NON_POSTED = 2 << 16,
 
        CICR_TOUT_IE            = BIT(0),       /* OMAP1 only */
        CICR_DROP_IE            = BIT(1),
@@ -881,15 +884,18 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
        unsigned i, es, en, frame_bytes;
        bool ll_failed = false;
        u32 burst;
+       u32 port_window, port_window_bytes;
 
        if (dir == DMA_DEV_TO_MEM) {
                dev_addr = c->cfg.src_addr;
                dev_width = c->cfg.src_addr_width;
                burst = c->cfg.src_maxburst;
+               port_window = c->cfg.src_port_window_size;
        } else if (dir == DMA_MEM_TO_DEV) {
                dev_addr = c->cfg.dst_addr;
                dev_width = c->cfg.dst_addr_width;
                burst = c->cfg.dst_maxburst;
+               port_window = c->cfg.dst_port_window_size;
        } else {
                dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
                return NULL;
@@ -910,6 +916,12 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
                return NULL;
        }
 
+       /* When the port_window is used, one frame must cover the window */
+       if (port_window) {
+               burst = port_window;
+               port_window_bytes = port_window * es_bytes[es];
+       }
+
        /* Now allocate and setup the descriptor. */
        d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
        if (!d)
@@ -921,11 +933,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
 
        d->ccr = c->ccr | CCR_SYNC_FRAME;
        if (dir == DMA_DEV_TO_MEM) {
-               d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
                d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
+
+               d->ccr |= CCR_DST_AMODE_POSTINC;
+               if (port_window) {
+                       d->ccr |= CCR_SRC_AMODE_DBLIDX;
+                       d->ei = 1;
+                       /*
+                        * One frame covers the port_window and by  configure
+                        * the source frame index to be -1 * (port_window - 1)
+                        * we instruct the sDMA that after a frame is processed
+                        * it should move back to the start of the window.
+                        */
+                       d->fi = -(port_window_bytes - 1);
+
+                       if (port_window_bytes >= 64)
+                               d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
+                       else if (port_window_bytes >= 32)
+                               d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
+                       else if (port_window_bytes >= 16)
+                               d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
+               } else {
+                       d->ccr |= CCR_SRC_AMODE_CONSTANT;
+               }
        } else {
-               d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
                d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
+
+               d->ccr |= CCR_SRC_AMODE_POSTINC;
+               if (port_window) {
+                       d->ccr |= CCR_DST_AMODE_DBLIDX;
+
+                       if (port_window_bytes >= 64)
+                               d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
+                       else if (port_window_bytes >= 32)
+                               d->csdp = CSDP_DST_BURST_32 | CSDP_DST_PACKED;
+                       else if (port_window_bytes >= 16)
+                               d->csdp = CSDP_DST_BURST_16 | CSDP_DST_PACKED;
+               } else {
+                       d->ccr |= CCR_DST_AMODE_CONSTANT;
+               }
        }
 
        d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
@@ -943,6 +989,9 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
                        d->ccr |= CCR_TRIGGER_SRC;
 
                d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
+
+               if (port_window)
+                       d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
        }
        if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
                d->clnk_ctrl = c->dma_ch;
@@ -968,6 +1017,16 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
                osg->addr = sg_dma_address(sgent);
                osg->en = en;
                osg->fn = sg_dma_len(sgent) / frame_bytes;
+               if (port_window && dir == DMA_MEM_TO_DEV) {
+                       osg->ei = 1;
+                       /*
+                        * One frame covers the port_window and by  configure
+                        * the source frame index to be -1 * (port_window - 1)
+                        * we instruct the sDMA that after a frame is processed
+                        * it should move back to the start of the window.
+                        */
+                       osg->fi = -(port_window_bytes - 1);
+               }
 
                if (d->using_ll) {
                        osg->t2_desc = dma_pool_alloc(od->desc_pool, GFP_ATOMIC,