From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Add dma_memcopy support to bcm2835-dma.
Also added check for an error condition in bcm2835_dma_create_cb_chain
that showed up during development of this patch.
Tested using dmatest for all 11 available dma channels with the
following output:
[ 476.543529] dmatest: Started 1 threads using dma0chan0
[ 489.011154] dmatest: dma0chan0-copy0: summary 10000 tests, 0 failures 802 iops 6452 KB/s (0)
[ 489.078379] dmatest: Started 1 threads using dma0chan1
[ 501.494448] dmatest: dma0chan1-copy0: summary 10000 tests, 0 failures 806 iops 6376 KB/s (0)
[ 501.562567] dmatest: Started 1 threads using dma0chan10
[ 514.515164] dmatest: dma0chan10-copy: summary 10000 tests, 0 failures 772 iops 6169 KB/s (0)
[ 514.582969] dmatest: Started 1 threads using dma0chan2
[ 527.092284] dmatest: dma0chan2-copy0: summary 10000 tests, 0 failures 800 iops 6405 KB/s (0)
[ 527.160290] dmatest: Started 1 threads using dma0chan3
[ 539.541064] dmatest: dma0chan3-copy0: summary 10000 tests, 0 failures 808 iops 6424 KB/s (0)
[ 539.608849] dmatest: Started 1 threads using dma0chan4
[ 552.402978] dmatest: dma0chan4-copy0: summary 10000 tests, 0 failures 782 iops 6286 KB/s (0)
[ 552.470852] dmatest: Started 1 threads using dma0chan5
[ 565.184158] dmatest: dma0chan5-copy0: summary 10000 tests, 0 failures 787 iops 6231 KB/s (0)
[ 565.251846] dmatest: Started 1 threads using dma0chan6
[ 577.959385] dmatest: dma0chan6-copy0: summary 10000 tests, 0 failures 787 iops 6244 KB/s (0)
[ 578.027259] dmatest: Started 1 threads using dma0chan7
[ 590.834078] dmatest: dma0chan7-copy0: summary 10000 tests, 0 failures 781 iops 6295 KB/s (0)
[ 590.901668] dmatest: Started 1 threads using dma0chan8
[ 603.640192] dmatest: dma0chan8-copy0: summary 10000 tests, 0 failures 785 iops 6265 KB/s (0)
[ 603.708531] dmatest: Started 1 threads using dma0chan9
[ 616.420882] dmatest: dma0chan9-copy0: summary 10000 tests, 0 failures 787 iops 6285 KB/s (0)
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/dma/bcm2835-dma.c | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 6c4b4e2..2884285 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -326,6 +326,9 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
struct bcm2835_cb_entry *cb_entry;
struct bcm2835_dma_cb *control_block;
+ if (!frames)
+ return NULL;
+
/* allocate and setup the descriptor. */
d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
gfp);
@@ -623,6 +626,34 @@ static void bcm2835_dma_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&c->vc.lock, flags);
}
+struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
+ struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
+ size_t len, unsigned long flags)
+{
+ struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
+ struct bcm2835_desc *d;
+ u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
+ u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
+ size_t max_len = bcm2835_dma_max_frame_length(c);
+ size_t frames;
+
+ /* if src, dst or len is not given return with an error */
+ if (!src || !dst || !len)
+ return NULL;
+
+ /* calculate number of frames */
+ frames = bcm2835_dma_frames_for_length(len, max_len);
+
+ /* allocate the CB chain - this also fills in the pointers */
+ d = bcm2835_dma_create_cb_chain(chan, DMA_MEM_TO_MEM, false,
+ info, extra, frames,
+ src, dst, len, 0, GFP_KERNEL);
+ if (!d)
+ return NULL;
+
+ return vchan_tx_prep(&c->vc, &d->vd, flags);
+}
+
static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
struct dma_chan *chan,
struct scatterlist *sgl, unsigned int sg_len,
@@ -909,17 +940,20 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
+ dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
od->ddev.device_tx_status = bcm2835_dma_tx_status;
od->ddev.device_issue_pending = bcm2835_dma_issue_pending;
od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic;
od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg;
+ od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy;
od->ddev.device_config = bcm2835_dma_slave_config;
od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
- od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
+ BIT(DMA_MEM_TO_MEM);
od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);
--
2.1.4
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