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dmaengine: omap: add support for cyclic DMA 

Add support for cyclic DMA to the OMAP DMA engine driver.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2012-06-21 10:40:15 +01:00
parent 7c836bc7f9
commit 3a774ea91a
1 changed files with 89 additions and 4 deletions
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93
drivers/dma/omap-dma.c
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@ -33,6 +33,7 @@ struct omap_chan {
struct dma_slave_config cfg;
unsigned dma_sig;
bool cyclic;
int dma_ch;
struct omap_desc *desc;
@ -138,11 +139,15 @@ static void omap_dma_callback(int ch, u16 status, void *data)
spin_lock_irqsave(&c->vc.lock, flags);
d = c->desc;
if (d) {
if (++c->sgidx < d->sglen) {
omap_dma_start_sg(c, d, c->sgidx);
if (!c->cyclic) {
if (++c->sgidx < d->sglen) {
omap_dma_start_sg(c, d, c->sgidx);
} else {
omap_dma_start_desc(c);
vchan_cookie_complete(&d->vd);
}
} else {
omap_dma_start_desc(c);
vchan_cookie_complete(&d->vd);
vchan_cyclic_callback(&d->vd);
}
}
spin_unlock_irqrestore(&c->vc.lock, flags);
@ -358,6 +363,79 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
}
static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction dir, void *context)
{
struct omap_chan *c = to_omap_dma_chan(chan);
enum dma_slave_buswidth dev_width;
struct omap_desc *d;
dma_addr_t dev_addr;
unsigned es, sync_type;
u32 burst;
if (dir == DMA_DEV_TO_MEM) {
dev_addr = c->cfg.src_addr;
dev_width = c->cfg.src_addr_width;
burst = c->cfg.src_maxburst;
sync_type = OMAP_DMA_SRC_SYNC;
} 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;
sync_type = OMAP_DMA_DST_SYNC;
} else {
dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
return NULL;
}
/* Bus width translates to the element size (ES) */
switch (dev_width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
es = OMAP_DMA_DATA_TYPE_S8;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
es = OMAP_DMA_DATA_TYPE_S16;
break;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
es = OMAP_DMA_DATA_TYPE_S32;
break;
default: /* not reached */
return NULL;
}
/* Now allocate and setup the descriptor. */
d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
if (!d)
return NULL;
d->dir = dir;
d->dev_addr = dev_addr;
d->fi = burst;
d->es = es;
d->sync_mode = OMAP_DMA_SYNC_PACKET;
d->sync_type = sync_type;
d->periph_port = OMAP_DMA_PORT_MPUI;
d->sg[0].addr = buf_addr;
d->sg[0].en = period_len / es_bytes[es];
d->sg[0].fn = buf_len / period_len;
d->sglen = 1;
if (!c->cyclic) {
c->cyclic = true;
omap_dma_link_lch(c->dma_ch, c->dma_ch);
omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ);
omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ);
}
if (!cpu_class_is_omap1()) {
omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
}
return vchan_tx_prep(&c->vc, &d->vd, DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
}
static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg)
{
if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
@ -392,6 +470,11 @@ static int omap_dma_terminate_all(struct omap_chan *c)
omap_stop_dma(c->dma_ch);
}
if (c->cyclic) {
c->cyclic = false;
omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
}
vchan_get_all_descriptors(&c->vc, &head);
spin_unlock_irqrestore(&c->vc.lock, flags);
vchan_dma_desc_free_list(&c->vc, &head);
@ -484,11 +567,13 @@ static int omap_dma_probe(struct platform_device *pdev)
return -ENOMEM;
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
od->ddev.device_tx_status = omap_dma_tx_status;
od->ddev.device_issue_pending = omap_dma_issue_pending;
od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
od->ddev.device_control = omap_dma_control;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);