Add support for cyclic DMA to the OMAP DMA engine driver.
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
drivers/dma/omap-dma.c | 93 +++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 89 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index e1a326d..dae9c2c 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -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);
--
1.7.4.4
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