diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/s3c24xx-dma.c | 112 |
1 files changed, 111 insertions, 1 deletions
diff --git a/drivers/dma/s3c24xx-dma.c b/drivers/dma/s3c24xx-dma.c index 6528eed..012520c 100644 --- a/drivers/dma/s3c24xx-dma.c +++ b/drivers/dma/s3c24xx-dma.c @@ -164,6 +164,7 @@ struct s3c24xx_sg { * @disrcc: value for source control register * @didstc: value for destination control register * @dcon: base value for dcon register + * @cyclic: indicate cyclic transfer */ struct s3c24xx_txd { struct virt_dma_desc vd; @@ -173,6 +174,7 @@ struct s3c24xx_txd { u32 disrcc; u32 didstc; u32 dcon; + bool cyclic; }; struct s3c24xx_dma_chan; @@ -669,8 +671,10 @@ static irqreturn_t s3c24xx_dma_irq(int irq, void *data) /* when more sg's are in this txd, start the next one */ if (!list_is_last(txd->at, &txd->dsg_list)) { txd->at = txd->at->next; + if (txd->cyclic) + vchan_cyclic_callback(&txd->vd); s3c24xx_dma_start_next_sg(s3cchan, txd); - } else { + } else if (!txd->cyclic) { s3cchan->at = NULL; vchan_cookie_complete(&txd->vd); @@ -682,6 +686,12 @@ static irqreturn_t s3c24xx_dma_irq(int irq, void *data) s3c24xx_dma_start_next_txd(s3cchan); else s3c24xx_dma_phy_free(s3cchan); + } else { + vchan_cyclic_callback(&txd->vd); + + /* Cyclic: reset at beginning */ + txd->at = txd->dsg_list.next; + s3c24xx_dma_start_next_sg(s3cchan, txd); } } spin_unlock(&s3cchan->vc.lock); @@ -877,6 +887,104 @@ static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy( return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); } +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t addr, size_t size, size_t period, + enum dma_transfer_direction direction, unsigned long flags, + void *context) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; + struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; + struct s3c24xx_txd *txd; + struct s3c24xx_sg *dsg; + unsigned sg_len; + dma_addr_t slave_addr; + u32 hwcfg = 0; + int i; + + dev_dbg(&s3cdma->pdev->dev, + "prepare cyclic transaction of %zu bytes with period %zu from %s\n", + size, period, s3cchan->name); + + if (!is_slave_direction(direction)) { + dev_err(&s3cdma->pdev->dev, + "direction %d unsupported\n", direction); + return NULL; + } + + txd = s3c24xx_dma_get_txd(); + if (!txd) + return NULL; + + txd->cyclic = 1; + + if (cdata->handshake) + txd->dcon |= S3C24XX_DCON_HANDSHAKE; + + switch (cdata->bus) { + case S3C24XX_DMA_APB: + txd->dcon |= S3C24XX_DCON_SYNC_PCLK; + hwcfg |= S3C24XX_DISRCC_LOC_APB; + break; + case S3C24XX_DMA_AHB: + txd->dcon |= S3C24XX_DCON_SYNC_HCLK; + hwcfg |= S3C24XX_DISRCC_LOC_AHB; + break; + } + + /* + * Always assume our peripheral desintation is a fixed + * address in memory. + */ + hwcfg |= S3C24XX_DISRCC_INC_FIXED; + + /* + * Individual dma operations are requested by the slave, + * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE). + */ + txd->dcon |= S3C24XX_DCON_SERV_SINGLE; + + if (direction == DMA_MEM_TO_DEV) { + txd->disrcc = S3C24XX_DISRCC_LOC_AHB | + S3C24XX_DISRCC_INC_INCREMENT; + txd->didstc = hwcfg; + slave_addr = s3cchan->cfg.dst_addr; + txd->width = s3cchan->cfg.dst_addr_width; + } else { + txd->disrcc = hwcfg; + txd->didstc = S3C24XX_DIDSTC_LOC_AHB | + S3C24XX_DIDSTC_INC_INCREMENT; + slave_addr = s3cchan->cfg.src_addr; + txd->width = s3cchan->cfg.src_addr_width; + } + + sg_len = size / period; + + for (i = 0; i < sg_len; i++) { + dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT); + if (!dsg) { + s3c24xx_dma_free_txd(txd); + return NULL; + } + list_add_tail(&dsg->node, &txd->dsg_list); + + dsg->len = period; + /* Check last period length */ + if (i == sg_len - 1) + dsg->len = size - period * i; + if (direction == DMA_MEM_TO_DEV) { + dsg->src_addr = addr + period * i; + dsg->dst_addr = slave_addr; + } else { /* DMA_DEV_TO_MEM */ + dsg->src_addr = slave_addr; + dsg->dst_addr = addr + period * i; + } + } + + return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); +} + static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, @@ -1197,6 +1305,7 @@ static int s3c24xx_dma_probe(struct platform_device *pdev) /* Initialize slave engine for SoC internal dedicated peripherals */ dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask); + dma_cap_set(DMA_CYCLIC, s3cdma->slave.cap_mask); dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask); s3cdma->slave.dev = &pdev->dev; s3cdma->slave.device_alloc_chan_resources = @@ -1206,6 +1315,7 @@ static int s3c24xx_dma_probe(struct platform_device *pdev) s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status; s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending; s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg; + s3cdma->slave.device_prep_dma_cyclic = s3c24xx_dma_prep_dma_cyclic; s3cdma->slave.device_control = s3c24xx_dma_control; /* Register as many memcpy channels as there are physical channels */ |
