dmaengine: s3c24xx-dma: Add cyclic transfer support
Many audio interface drivers require support of cyclic transfers to work
correctly, for example Samsung ASoC DMA driver. This patch adds support
for cyclic transfers to the s3c24xx-dma driver
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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 @@
* @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 @@
u32 disrcc;
u32 didstc;
u32 dcon;
+ bool cyclic;
};
struct s3c24xx_dma_chan;
@@ -669,8 +671,10 @@
/* 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 @@
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 @@
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 @@
/* 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 @@
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 */