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@xxxxxx>
---
drivers/dma/omap-dma.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 61 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 15eb8024666b..ac68666cd3f4 100644
--- 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,
--
2.11.0.rc2
--
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