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path: root/drivers/dma/bcm2835-dma.c
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Diffstat (limited to 'drivers/dma/bcm2835-dma.c')
-rw-r--r--drivers/dma/bcm2835-dma.c27
1 files changed, 8 insertions, 19 deletions
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index ae10f5614f95..ec8a291d62ba 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -2,9 +2,6 @@
/*
* BCM2835 DMA engine support
*
- * This driver only supports cyclic DMA transfers
- * as needed for the I2S module.
- *
* Author: Florian Meier <florian.meier@koalo.de>
* Copyright 2013
*
@@ -42,7 +39,6 @@
struct bcm2835_dmadev {
struct dma_device ddev;
- spinlock_t lock;
void __iomem *base;
struct device_dma_parameters dma_parms;
};
@@ -64,7 +60,6 @@ struct bcm2835_cb_entry {
struct bcm2835_chan {
struct virt_dma_chan vc;
- struct list_head node;
struct dma_slave_config cfg;
unsigned int dreq;
@@ -312,8 +307,7 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
return NULL;
/* allocate and setup the descriptor. */
- d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
- gfp);
+ d = kzalloc(struct_size(d, cb_list, frames), gfp);
if (!d)
return NULL;
@@ -406,7 +400,7 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
}
}
-static int bcm2835_dma_abort(struct bcm2835_chan *c)
+static void bcm2835_dma_abort(struct bcm2835_chan *c)
{
void __iomem *chan_base = c->chan_base;
long int timeout = 10000;
@@ -416,7 +410,7 @@ static int bcm2835_dma_abort(struct bcm2835_chan *c)
* (The ACTIVE flag in the CS register is not a reliable indicator.)
*/
if (!readl(chan_base + BCM2835_DMA_ADDR))
- return 0;
+ return;
/* Write 0 to the active bit - Pause the DMA */
writel(0, chan_base + BCM2835_DMA_CS);
@@ -432,7 +426,6 @@ static int bcm2835_dma_abort(struct bcm2835_chan *c)
"failed to complete outstanding writes\n");
writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
- return 0;
}
static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
@@ -504,8 +497,12 @@ static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan)
dev_dbg(dev, "Allocating DMA channel %d\n", c->ch);
+ /*
+ * Control blocks are 256 bit in length and must start at a 256 bit
+ * (32 byte) aligned address (BCM2835 ARM Peripherals, sec. 4.2.1.1).
+ */
c->cb_pool = dma_pool_create(dev_name(dev), dev,
- sizeof(struct bcm2835_dma_cb), 0, 0);
+ sizeof(struct bcm2835_dma_cb), 32, 0);
if (!c->cb_pool) {
dev_err(dev, "unable to allocate descriptor pool\n");
return -ENOMEM;
@@ -774,17 +771,11 @@ static int bcm2835_dma_slave_config(struct dma_chan *chan,
static int bcm2835_dma_terminate_all(struct dma_chan *chan)
{
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
- struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&c->vc.lock, flags);
- /* Prevent this channel being scheduled */
- spin_lock(&d->lock);
- list_del_init(&c->node);
- spin_unlock(&d->lock);
-
/* stop DMA activity */
if (c->desc) {
vchan_terminate_vdesc(&c->desc->vd);
@@ -817,7 +808,6 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
c->vc.desc_free = bcm2835_dma_desc_free;
vchan_init(&c->vc, &d->ddev);
- INIT_LIST_HEAD(&c->node);
c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
c->ch = chan_id;
@@ -920,7 +910,6 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);
- spin_lock_init(&od->lock);
platform_set_drvdata(pdev, od);