diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/sa11x0-dma.c | 108 |
1 files changed, 92 insertions, 16 deletions
diff --git a/drivers/dma/sa11x0-dma.c b/drivers/dma/sa11x0-dma.c index db4fcbd80c7..f5a73606217 100644 --- a/drivers/dma/sa11x0-dma.c +++ b/drivers/dma/sa11x0-dma.c @@ -78,6 +78,8 @@ struct sa11x0_dma_desc { u32 ddar; size_t size; + unsigned period; + bool cyclic; unsigned sglen; struct sa11x0_dma_sg sg[0]; @@ -178,19 +180,24 @@ static void noinline sa11x0_dma_start_sg(struct sa11x0_dma_phy *p, return; if (p->sg_load == txd->sglen) { - struct sa11x0_dma_desc *txn = sa11x0_dma_next_desc(c); + if (!txd->cyclic) { + struct sa11x0_dma_desc *txn = sa11x0_dma_next_desc(c); - /* - * We have reached the end of the current descriptor. - * Peek at the next descriptor, and if compatible with - * the current, start processing it. - */ - if (txn && txn->ddar == txd->ddar) { - txd = txn; - sa11x0_dma_start_desc(p, txn); + /* + * We have reached the end of the current descriptor. + * Peek at the next descriptor, and if compatible with + * the current, start processing it. + */ + if (txn && txn->ddar == txd->ddar) { + txd = txn; + sa11x0_dma_start_desc(p, txn); + } else { + p->txd_load = NULL; + return; + } } else { - p->txd_load = NULL; - return; + /* Cyclic: reset back to beginning */ + p->sg_load = 0; } } @@ -224,13 +231,21 @@ static void noinline sa11x0_dma_complete(struct sa11x0_dma_phy *p, struct sa11x0_dma_desc *txd = p->txd_done; if (++p->sg_done == txd->sglen) { - vchan_cookie_complete(&txd->vd); + if (!txd->cyclic) { + vchan_cookie_complete(&txd->vd); - p->sg_done = 0; - p->txd_done = p->txd_load; + p->sg_done = 0; + p->txd_done = p->txd_load; + + if (!p->txd_done) + tasklet_schedule(&p->dev->task); + } else { + if ((p->sg_done % txd->period) == 0) + vchan_cyclic_callback(&txd->vd); - if (!p->txd_done) - tasklet_schedule(&p->dev->task); + /* Cyclic: reset back to beginning */ + p->sg_done = 0; + } } sa11x0_dma_start_sg(p, c); @@ -597,6 +612,65 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_slave_sg( return vchan_tx_prep(&c->vc, &txd->vd, flags); } +static struct dma_async_tx_descriptor *sa11x0_dma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t addr, size_t size, size_t period, + enum dma_transfer_direction dir, void *context) +{ + struct sa11x0_dma_chan *c = to_sa11x0_dma_chan(chan); + struct sa11x0_dma_desc *txd; + unsigned i, j, k, sglen, sgperiod; + + /* SA11x0 channels can only operate in their native direction */ + if (dir != (c->ddar & DDAR_RW ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV)) { + dev_err(chan->device->dev, "vchan %p: bad DMA direction: DDAR:%08x dir:%u\n", + &c->vc, c->ddar, dir); + return NULL; + } + + sgperiod = DIV_ROUND_UP(period, DMA_MAX_SIZE & ~DMA_ALIGN); + sglen = size * sgperiod / period; + + /* Do not allow zero-sized txds */ + if (sglen == 0) + return NULL; + + txd = kzalloc(sizeof(*txd) + sglen * sizeof(txd->sg[0]), GFP_ATOMIC); + if (!txd) { + dev_dbg(chan->device->dev, "vchan %p: kzalloc failed\n", &c->vc); + return NULL; + } + + for (i = k = 0; i < size / period; i++) { + size_t tlen, len = period; + + for (j = 0; j < sgperiod; j++, k++) { + tlen = len; + + if (tlen > DMA_MAX_SIZE) { + unsigned mult = DIV_ROUND_UP(tlen, DMA_MAX_SIZE & ~DMA_ALIGN); + tlen = (tlen / mult) & ~DMA_ALIGN; + } + + txd->sg[k].addr = addr; + txd->sg[k].len = tlen; + addr += tlen; + len -= tlen; + } + + WARN_ON(len != 0); + } + + WARN_ON(k != sglen); + + txd->ddar = c->ddar; + txd->size = size; + txd->sglen = sglen; + txd->cyclic = 1; + txd->period = sgperiod; + + return vchan_tx_prep(&c->vc, &txd->vd, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); +} + static int sa11x0_dma_slave_config(struct sa11x0_dma_chan *c, struct dma_slave_config *cfg) { u32 ddar = c->ddar & ((0xf << 4) | DDAR_RW); @@ -867,7 +941,9 @@ static int __devinit sa11x0_dma_probe(struct platform_device *pdev) } dma_cap_set(DMA_SLAVE, d->slave.cap_mask); + dma_cap_set(DMA_CYCLIC, d->slave.cap_mask); d->slave.device_prep_slave_sg = sa11x0_dma_prep_slave_sg; + d->slave.device_prep_dma_cyclic = sa11x0_dma_prep_dma_cyclic; ret = sa11x0_dma_init_dmadev(&d->slave, &pdev->dev); if (ret) { dev_warn(d->slave.dev, "failed to register slave async device: %d\n", |