diff options
Diffstat (limited to 'drivers/dma/edma.c')
-rw-r--r-- | drivers/dma/edma.c | 88 |
1 files changed, 58 insertions, 30 deletions
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 2dac314a2..04070baab 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -869,6 +869,13 @@ static int edma_terminate_all(struct dma_chan *chan) return 0; } +static void edma_synchronize(struct dma_chan *chan) +{ + struct edma_chan *echan = to_edma_chan(chan); + + vchan_synchronize(&echan->vchan); +} + static int edma_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg) { @@ -1231,6 +1238,7 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( struct edma_desc *edesc; dma_addr_t src_addr, dst_addr; enum dma_slave_buswidth dev_width; + bool use_intermediate = false; u32 burst; int i, ret, nslots; @@ -1272,8 +1280,21 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( * but the synchronization is difficult to achieve with Cyclic and * cannot be guaranteed, so we error out early. */ - if (nslots > MAX_NR_SG) - return NULL; + if (nslots > MAX_NR_SG) { + /* + * If the burst and period sizes are the same, we can put + * the full buffer into a single period and activate + * intermediate interrupts. This will produce interrupts + * after each burst, which is also after each desired period. + */ + if (burst == period_len) { + period_len = buf_len; + nslots = 2; + use_intermediate = true; + } else { + return NULL; + } + } edesc = kzalloc(sizeof(*edesc) + nslots * sizeof(edesc->pset[0]), GFP_ATOMIC); @@ -1351,8 +1372,13 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( /* * Enable period interrupt only if it is requested */ - if (tx_flags & DMA_PREP_INTERRUPT) + if (tx_flags & DMA_PREP_INTERRUPT) { edesc->pset[i].param.opt |= TCINTEN; + + /* Also enable intermediate interrupts if necessary */ + if (use_intermediate) + edesc->pset[i].param.opt |= ITCINTEN; + } } /* Place the cyclic channel to highest priority queue */ @@ -1365,36 +1391,36 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( static void edma_completion_handler(struct edma_chan *echan) { struct device *dev = echan->vchan.chan.device->dev; - struct edma_desc *edesc = echan->edesc; - - if (!edesc) - return; + struct edma_desc *edesc; spin_lock(&echan->vchan.lock); - if (edesc->cyclic) { - vchan_cyclic_callback(&edesc->vdesc); - spin_unlock(&echan->vchan.lock); - return; - } else if (edesc->processed == edesc->pset_nr) { - edesc->residue = 0; - edma_stop(echan); - vchan_cookie_complete(&edesc->vdesc); - echan->edesc = NULL; - - dev_dbg(dev, "Transfer completed on channel %d\n", - echan->ch_num); - } else { - dev_dbg(dev, "Sub transfer completed on channel %d\n", - echan->ch_num); - - edma_pause(echan); - - /* Update statistics for tx_status */ - edesc->residue -= edesc->sg_len; - edesc->residue_stat = edesc->residue; - edesc->processed_stat = edesc->processed; + edesc = echan->edesc; + if (edesc) { + if (edesc->cyclic) { + vchan_cyclic_callback(&edesc->vdesc); + spin_unlock(&echan->vchan.lock); + return; + } else if (edesc->processed == edesc->pset_nr) { + edesc->residue = 0; + edma_stop(echan); + vchan_cookie_complete(&edesc->vdesc); + echan->edesc = NULL; + + dev_dbg(dev, "Transfer completed on channel %d\n", + echan->ch_num); + } else { + dev_dbg(dev, "Sub transfer completed on channel %d\n", + echan->ch_num); + + edma_pause(echan); + + /* Update statistics for tx_status */ + edesc->residue -= edesc->sg_len; + edesc->residue_stat = edesc->residue; + edesc->processed_stat = edesc->processed; + } + edma_execute(echan); } - edma_execute(echan); spin_unlock(&echan->vchan.lock); } @@ -1808,6 +1834,7 @@ static void edma_dma_init(struct edma_cc *ecc, bool legacy_mode) s_ddev->device_pause = edma_dma_pause; s_ddev->device_resume = edma_dma_resume; s_ddev->device_terminate_all = edma_terminate_all; + s_ddev->device_synchronize = edma_synchronize; s_ddev->src_addr_widths = EDMA_DMA_BUSWIDTHS; s_ddev->dst_addr_widths = EDMA_DMA_BUSWIDTHS; @@ -1833,6 +1860,7 @@ static void edma_dma_init(struct edma_cc *ecc, bool legacy_mode) m_ddev->device_pause = edma_dma_pause; m_ddev->device_resume = edma_dma_resume; m_ddev->device_terminate_all = edma_terminate_all; + m_ddev->device_synchronize = edma_synchronize; m_ddev->src_addr_widths = EDMA_DMA_BUSWIDTHS; m_ddev->dst_addr_widths = EDMA_DMA_BUSWIDTHS; |