@@ -48,6 +48,11 @@ struct bcm2835_dmadev {
struct dma_device ddev;
void __iomem *base;
dma_addr_t zero_page;
+ const struct bcm2835_dma_cfg *cfg;
+};
+
+struct bcm_dma_cb {
+ uint32_t rsvd[8];
};
struct bcm2835_dma_cb {
@@ -61,7 +66,7 @@ struct bcm2835_dma_cb {
};
struct bcm2835_cb_entry {
- struct bcm2835_dma_cb *cb;
+ struct bcm_dma_cb *cb;
dma_addr_t paddr;
};
@@ -82,6 +87,38 @@ struct bcm2835_chan {
bool is_lite_channel;
};
+struct bcm2835_dma_cfg {
+ dma_addr_t addr_offset;
+ u32 cs_reg;
+ u32 cb_reg;
+
+ u32 wait_mask;
+ u32 reset_mask;
+ u32 int_mask;
+ u32 active_mask;
+
+ u32 (*cb_get_length)(void *data);
+ dma_addr_t (*cb_get_addr)(void *data, enum dma_transfer_direction);
+
+ void (*cb_init)(void *data, struct bcm2835_chan *c,
+ enum dma_transfer_direction, u32 src, u32 dst,
+ bool zero_page);
+ void (*cb_set_src)(void *data, enum dma_transfer_direction, u32 src);
+ void (*cb_set_dst)(void *data, enum dma_transfer_direction, u32 dst);
+ void (*cb_set_next)(void *data, u32 next);
+ void (*cb_set_length)(void *data, u32 length);
+ void (*cb_append_extra)(void *data,
+ struct bcm2835_chan *c,
+ enum dma_transfer_direction direction,
+ bool cyclic, bool final, unsigned long flags);
+
+ u32 (*to_cb_addr)(dma_addr_t addr);
+
+ void (*chan_plat_init)(struct bcm2835_chan *c);
+ dma_addr_t (*read_addr)(struct bcm2835_chan *c,
+ enum dma_transfer_direction);
+};
+
struct bcm2835_desc {
struct bcm2835_chan *c;
struct virt_dma_desc vd;
@@ -190,6 +227,13 @@ static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d)
return container_of(d, struct bcm2835_dmadev, ddev);
}
+static inline const struct bcm2835_dma_cfg *to_bcm2835_cfg(struct dma_device *d)
+{
+ struct bcm2835_dmadev *od = container_of(d, struct bcm2835_dmadev, ddev);
+
+ return od->cfg;
+}
+
static inline struct bcm2835_chan *to_bcm2835_dma_chan(struct dma_chan *c)
{
return container_of(c, struct bcm2835_chan, vc.chan);
@@ -271,6 +315,104 @@ static inline bool need_dst_incr(enum dma_transfer_direction direction)
return false;
}
+static inline u32 bcm2835_dma_cb_get_length(void *data)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ return cb->length;
+}
+
+static inline dma_addr_t
+bcm2835_dma_cb_get_addr(void *data, enum dma_transfer_direction direction)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ if (direction == DMA_DEV_TO_MEM)
+ return cb->dst;
+
+ return cb->src;
+}
+
+static inline void
+bcm2835_dma_cb_init(void *data, struct bcm2835_chan *c,
+ enum dma_transfer_direction direction, u32 src, u32 dst,
+ bool zero_page)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->info = bcm2835_dma_prepare_cb_info(c, direction, zero_page);
+ cb->src = src;
+ cb->dst = dst;
+ cb->stride = 0;
+ cb->next = 0;
+}
+
+static inline void
+bcm2835_dma_cb_set_src(void *data, enum dma_transfer_direction direction,
+ u32 src)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->src = src;
+}
+
+static inline void
+bcm2835_dma_cb_set_dst(void *data, enum dma_transfer_direction direction,
+ u32 dst)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->dst = dst;
+}
+
+static inline void bcm2835_dma_cb_set_next(void *data, u32 next)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->next = next;
+}
+
+static inline void bcm2835_dma_cb_set_length(void *data, u32 length)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->length = length;
+}
+
+static inline void
+bcm2835_dma_cb_append_extra(void *data, struct bcm2835_chan *c,
+ enum dma_transfer_direction direction,
+ bool cyclic, bool final, unsigned long flags)
+{
+ struct bcm2835_dma_cb *cb = data;
+
+ cb->info |= bcm2835_dma_prepare_cb_extra(c, direction, cyclic, final,
+ flags);
+}
+
+static inline dma_addr_t bcm2835_dma_to_cb_addr(dma_addr_t addr)
+{
+ return addr;
+}
+
+static void bcm2835_dma_chan_plat_init(struct bcm2835_chan *c)
+{
+ /* check in DEBUG register if this is a LITE channel */
+ if (readl(c->chan_base + BCM2835_DMA_DEBUG) & BCM2835_DMA_DEBUG_LITE)
+ c->is_lite_channel = true;
+}
+
+static dma_addr_t bcm2835_dma_read_addr(struct bcm2835_chan *c,
+ enum dma_transfer_direction direction)
+{
+ if (direction == DMA_MEM_TO_DEV)
+ return readl(c->chan_base + BCM2835_DMA_SOURCE_AD);
+ else if (direction == DMA_DEV_TO_MEM)
+ return readl(c->chan_base + BCM2835_DMA_DEST_AD);
+
+ return 0;
+}
+
static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc)
{
size_t i;
@@ -290,16 +432,19 @@ static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
static bool bcm2835_dma_create_cb_set_length(
struct dma_chan *chan,
- struct bcm2835_dma_cb *control_block,
+ void *data,
size_t len,
size_t period_len,
size_t *total_len)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
size_t max_len = bcm2835_dma_max_frame_length(c);
/* set the length taking lite-channel limitations into account */
- control_block->length = min_t(u32, len, max_len);
+ u32 length = min_t(u32, len, max_len);
+
+ cfg->cb_set_length(data, length);
/* finished if we have no period_length */
if (!period_len)
@@ -314,14 +459,14 @@ static bool bcm2835_dma_create_cb_set_length(
*/
/* have we filled in period_length yet? */
- if (*total_len + control_block->length < period_len) {
+ if (*total_len + length < period_len) {
/* update number of bytes in this period so far */
- *total_len += control_block->length;
+ *total_len += length;
return false;
}
/* calculate the length that remains to reach period_length */
- control_block->length = period_len - *total_len;
+ cfg->cb_set_length(data, period_len - *total_len);
/* reset total_length for next period */
*total_len = 0;
@@ -367,15 +512,14 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
bool cyclic, size_t frames, dma_addr_t src, dma_addr_t dst,
size_t buf_len, size_t period_len, gfp_t gfp, unsigned long flags)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_dmadev *od = to_bcm2835_dma_dev(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
size_t len = buf_len, total_len;
size_t frame;
struct bcm2835_desc *d;
struct bcm2835_cb_entry *cb_entry;
- struct bcm2835_dma_cb *control_block;
- u32 extrainfo = bcm2835_dma_prepare_cb_extra(c, direction, cyclic,
- false, flags);
+ struct bcm_dma_cb *control_block;
bool zero_page = false;
if (!frames)
@@ -412,12 +556,7 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
/* fill in the control block */
control_block = cb_entry->cb;
- control_block->info = bcm2835_dma_prepare_cb_info(c, direction,
- zero_page);
- control_block->src = src;
- control_block->dst = dst;
- control_block->stride = 0;
- control_block->next = 0;
+ cfg->cb_init(control_block, c, src, dst, direction, zero_page);
/* set up length in control_block if requested */
if (buf_len) {
/* calculate length honoring period_length */
@@ -425,31 +564,33 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
chan, control_block,
len, period_len, &total_len)) {
/* add extrainfo bits in info */
- control_block->info |= extrainfo;
+ bcm2835_dma_cb_append_extra(control_block, c,
+ direction, cyclic,
+ false, flags);
}
/* calculate new remaining length */
- len -= control_block->length;
+ len -= cfg->cb_get_length(control_block);
}
/* link this the last controlblock */
if (frame)
- d->cb_list[frame - 1].cb->next = cb_entry->paddr;
+ cfg->cb_set_next(d->cb_list[frame - 1].cb,
+ cb_entry->paddr);
/* update src and dst and length */
if (src && need_src_incr(direction))
- src += control_block->length;
+ src += cfg->cb_get_length(control_block);
if (dst && need_dst_incr(direction))
- dst += control_block->length;
+ dst += cfg->cb_get_length(control_block);
/* Length of total transfer */
- d->size += control_block->length;
+ d->size += cfg->cb_get_length(control_block);
}
/* the last frame requires extra flags */
- extrainfo = bcm2835_dma_prepare_cb_extra(c, direction, cyclic, true,
- flags);
- d->cb_list[d->frames - 1].cb->info |= extrainfo;
+ cfg->cb_append_extra(d->cb_list[d->frames - 1].cb, c, direction, cyclic,
+ true, flags);
/* detect a size missmatch */
if (buf_len && (d->size != buf_len))
@@ -469,6 +610,7 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
struct scatterlist *sgl,
unsigned int sg_len)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
size_t len, max_len;
unsigned int i;
@@ -479,18 +621,19 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
for_each_sg(sgl, sgent, sg_len, i) {
for (addr = sg_dma_address(sgent), len = sg_dma_len(sgent);
len > 0;
- addr += cb->cb->length, len -= cb->cb->length, cb++) {
+ addr += cfg->cb_get_length(cb->cb), len -= cfg->cb_get_length(cb->cb), cb++) {
if (direction == DMA_DEV_TO_MEM)
- cb->cb->dst = addr;
+ cfg->cb_set_dst(cb->cb, direction, addr);
else
- cb->cb->src = addr;
- cb->cb->length = min(len, max_len);
+ cfg->cb_set_src(cb->cb, direction, addr);
+ cfg->cb_set_length(cb->cb, min(len, max_len));
}
}
}
static void bcm2835_dma_abort(struct dma_chan *chan)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
void __iomem *chan_base = c->chan_base;
long int timeout = 10000;
@@ -499,15 +642,15 @@ static void bcm2835_dma_abort(struct dma_chan *chan)
* A zero control block address means the channel is idle.
* (The ACTIVE flag in the CS register is not a reliable indicator.)
*/
- if (!readl(chan_base + BCM2835_DMA_ADDR))
+ if (!readl(chan_base + cfg->cb_reg))
return;
/* Write 0 to the active bit - Pause the DMA */
- writel(0, chan_base + BCM2835_DMA_CS);
+ writel(0, chan_base + cfg->cs_reg);
/* Wait for any current AXI transfer to complete */
- while ((readl(chan_base + BCM2835_DMA_CS) &
- BCM2835_DMA_WAITING_FOR_WRITES) && --timeout)
+ while ((readl(chan_base + cfg->cs_reg) & cfg->wait_mask) &&
+ --timeout)
cpu_relax();
/* Peripheral might be stuck and fail to signal AXI write responses */
@@ -515,11 +658,12 @@ static void bcm2835_dma_abort(struct dma_chan *chan)
dev_err(c->vc.chan.device->dev,
"failed to complete outstanding writes\n");
- writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
+ writel(cfg->reset_mask, chan_base + cfg->cs_reg);
}
static void bcm2835_dma_start_desc(struct dma_chan *chan)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
struct bcm2835_desc *d;
@@ -533,13 +677,14 @@ static void bcm2835_dma_start_desc(struct dma_chan *chan)
c->desc = d = to_bcm2835_dma_desc(&vd->tx);
- writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR);
- writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS);
+ writel(cfg->to_cb_addr(d->cb_list[0].paddr), c->chan_base + cfg->cb_reg);
+ writel(cfg->active_mask, c->chan_base + cfg->cs_reg);
}
static irqreturn_t bcm2835_dma_callback(int irq, void *data)
{
struct dma_chan *chan = data;
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d;
unsigned long flags;
@@ -547,9 +692,9 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
/* check the shared interrupt */
if (c->irq_flags & IRQF_SHARED) {
/* check if the interrupt is enabled */
- flags = readl(c->chan_base + BCM2835_DMA_CS);
+ flags = readl(c->chan_base + cfg->cs_reg);
/* if not set then we are not the reason for the irq */
- if (!(flags & BCM2835_DMA_INT))
+ if (!(flags & cfg->int_mask))
return IRQ_NONE;
}
@@ -562,8 +707,7 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
* if this IRQ handler is threaded.) If the channel is finished, it
* will remain idle despite the ACTIVE flag being set.
*/
- writel(BCM2835_DMA_INT | BCM2835_DMA_ACTIVE,
- c->chan_base + BCM2835_DMA_CS);
+ writel(cfg->int_mask | cfg->active_mask, c->chan_base + cfg->cs_reg);
d = c->desc;
@@ -571,7 +715,7 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
if (d->cyclic) {
/* call the cyclic callback */
vchan_cyclic_callback(&d->vd);
- } else if (!readl(c->chan_base + BCM2835_DMA_ADDR)) {
+ } else if (!readl(c->chan_base + cfg->cb_reg)) {
vchan_cookie_complete(&c->desc->vd);
bcm2835_dma_start_desc(chan);
}
@@ -594,7 +738,7 @@ static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan)
* (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), 32, 0);
+ sizeof(struct bcm_dma_cb), 32, 0);
if (!c->cb_pool) {
dev_err(dev, "unable to allocate descriptor pool\n");
return -ENOMEM;
@@ -620,20 +764,16 @@ static size_t bcm2835_dma_desc_size(struct bcm2835_desc *d)
return d->size;
}
-static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr)
+static size_t bcm2835_dma_desc_size_pos(const struct bcm2835_dma_cfg *cfg,
+ struct bcm2835_desc *d, dma_addr_t addr)
{
unsigned int i;
size_t size;
for (size = i = 0; i < d->frames; i++) {
- struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
- size_t this_size = control_block->length;
- dma_addr_t dma;
-
- if (d->dir == DMA_DEV_TO_MEM)
- dma = control_block->dst;
- else
- dma = control_block->src;
+ struct bcm_dma_cb *control_block = d->cb_list[i].cb;
+ size_t this_size = cfg->cb_get_length(control_block);
+ dma_addr_t dma = cfg->cb_get_addr(control_block, d->dir);
if (size)
size += this_size;
@@ -647,6 +787,7 @@ static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr)
static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct virt_dma_desc *vd;
enum dma_status ret;
@@ -665,14 +806,8 @@ static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan,
struct bcm2835_desc *d = c->desc;
dma_addr_t pos;
- if (d->dir == DMA_MEM_TO_DEV)
- pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD);
- else if (d->dir == DMA_DEV_TO_MEM)
- pos = readl(c->chan_base + BCM2835_DMA_DEST_AD);
- else
- pos = 0;
-
- txstate->residue = bcm2835_dma_desc_size_pos(d, pos);
+ pos = cfg->read_addr(c, d->dir);
+ txstate->residue = bcm2835_dma_desc_size_pos(cfg, d, pos);
} else {
txstate->residue = 0;
}
@@ -725,6 +860,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d;
dma_addr_t src = 0, dst = 0;
@@ -739,11 +875,11 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
if (direction == DMA_DEV_TO_MEM) {
if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
- src = c->cfg.src_addr;
+ src = cfg->addr_offset + c->cfg.src_addr;
} else {
if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
- dst = c->cfg.dst_addr;
+ dst = cfg->addr_offset + c->cfg.dst_addr;
}
/* count frames in sg list */
@@ -767,6 +903,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags)
{
+ const struct bcm2835_dma_cfg *cfg = to_bcm2835_cfg(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d;
dma_addr_t src, dst;
@@ -800,12 +937,12 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
if (direction == DMA_DEV_TO_MEM) {
if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
- src = c->cfg.src_addr;
+ src = cfg->addr_offset + c->cfg.src_addr;
dst = buf_addr;
} else {
if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return NULL;
- dst = c->cfg.dst_addr;
+ dst = cfg->addr_offset + c->cfg.dst_addr;
src = buf_addr;
}
@@ -826,7 +963,8 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
return NULL;
/* wrap around into a loop */
- d->cb_list[d->frames - 1].cb->next = d->cb_list[0].paddr;
+ cfg->cb_set_next(d->cb_list[d->frames - 1].cb,
+ cfg->to_cb_addr(d->cb_list[0].paddr));
return vchan_tx_prep(&c->vc, &d->vd, flags);
}
@@ -887,10 +1025,7 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
c->irq_number = irq;
c->irq_flags = irq_flags;
- /* check in DEBUG register if this is a LITE channel */
- if (readl(c->chan_base + BCM2835_DMA_DEBUG) &
- BCM2835_DMA_DEBUG_LITE)
- c->is_lite_channel = true;
+ d->cfg->chan_plat_init(c);
return 0;
}
@@ -909,8 +1044,34 @@ static void bcm2835_dma_free(struct bcm2835_dmadev *od)
DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
}
+static const struct bcm2835_dma_cfg bcm2835_data = {
+ .addr_offset = 0,
+
+ .cs_reg = BCM2835_DMA_CS,
+ .cb_reg = BCM2835_DMA_ADDR,
+
+ .wait_mask = BCM2835_DMA_WAITING_FOR_WRITES,
+ .reset_mask = BCM2835_DMA_RESET,
+ .int_mask = BCM2835_DMA_INT,
+ .active_mask = BCM2835_DMA_ACTIVE,
+
+ .cb_get_length = bcm2835_dma_cb_get_length,
+ .cb_get_addr = bcm2835_dma_cb_get_addr,
+ .cb_init = bcm2835_dma_cb_init,
+ .cb_set_src = bcm2835_dma_cb_set_src,
+ .cb_set_dst = bcm2835_dma_cb_set_dst,
+ .cb_set_next = bcm2835_dma_cb_set_next,
+ .cb_set_length = bcm2835_dma_cb_set_length,
+ .cb_append_extra = bcm2835_dma_cb_append_extra,
+
+ .to_cb_addr = bcm2835_dma_to_cb_addr,
+
+ .chan_plat_init = bcm2835_dma_chan_plat_init,
+ .read_addr = bcm2835_dma_read_addr,
+};
+
static const struct of_device_id bcm2835_dma_of_match[] = {
- { .compatible = "brcm,bcm2835-dma", },
+ { .compatible = "brcm,bcm2835-dma", .data = &bcm2835_data },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match);
@@ -933,6 +1094,7 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
static int bcm2835_dma_probe(struct platform_device *pdev)
{
+ const struct of_device_id *of_id;
struct bcm2835_dmadev *od;
struct resource *res;
void __iomem *base;
@@ -943,6 +1105,10 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
uint32_t chans_available;
char chan_name[BCM2835_DMA_CHAN_NAME_SIZE];
+ of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node);
+ if (!of_id)
+ return -EINVAL;
+
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
@@ -964,6 +1130,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
return PTR_ERR(base);
od->base = base;
+ od->cfg = of_id->data;
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
This finally moves all platform specific stuff into a separate structure, which is initialized on the OF compatible during probing. Since the DMA control block is different on the BCM2711 platform, we introduce a common control block to reserve the necessary space and adequate methods for access. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> --- drivers/dma/bcm2835-dma.c | 303 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 235 insertions(+), 68 deletions(-)