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path: root/drivers/dma/amba-pl08x.c
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Diffstat (limited to 'drivers/dma/amba-pl08x.c')
-rw-r--r--drivers/dma/amba-pl08x.c43
1 files changed, 36 insertions, 7 deletions
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index f739778..b579bac 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -296,6 +296,39 @@ static inline struct pl08x_txd *to_pl08x_txd(struct dma_async_tx_descriptor *tx)
}
/*
+ * Mux handling.
+ *
+ * This gives us the DMA request input to the PL08x primecell which the
+ * peripheral described by the channel data will be routed to, possibly
+ * via a board/SoC specific external MUX. One important point to note
+ * here is that this does not depend on the physical channel.
+ */
+static int pl08x_request_mux(struct pl08x_dma_chan *plchan, struct pl08x_phy_chan *ch)
+{
+ const struct pl08x_platform_data *pd = plchan->host->pd;
+ int ret;
+
+ if (pd->get_signal) {
+ ret = pd->get_signal(plchan->cd);
+ if (ret < 0)
+ return ret;
+
+ ch->signal = ret;
+ }
+ return 0;
+}
+
+static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
+{
+ const struct pl08x_platform_data *pd = plchan->host->pd;
+
+ if (plchan->phychan->signal >= 0 && pd->put_signal) {
+ pd->put_signal(plchan->cd, plchan->phychan->signal);
+ plchan->phychan->signal = -1;
+ }
+}
+
+/*
* Physical channel handling
*/
@@ -999,8 +1032,8 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
* need, but for slaves the physical signals may be muxed!
* Can the platform allow us to use this channel?
*/
- if (plchan->slave && pl08x->pd->get_signal) {
- ret = pl08x->pd->get_signal(plchan->cd);
+ if (plchan->slave) {
+ ret = pl08x_request_mux(plchan, ch);
if (ret < 0) {
dev_dbg(&pl08x->adev->dev,
"unable to use physical channel %d for transfer on %s due to platform restrictions\n",
@@ -1009,7 +1042,6 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
pl08x_put_phy_channel(pl08x, ch);
return -EBUSY;
}
- ch->signal = ret;
}
plchan->phychan = ch;
@@ -1034,10 +1066,7 @@ static void release_phy_channel(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
- if ((plchan->phychan->signal >= 0) && pl08x->pd->put_signal) {
- pl08x->pd->put_signal(plchan->cd, plchan->phychan->signal);
- plchan->phychan->signal = -1;
- }
+ pl08x_release_mux(plchan);
pl08x_put_phy_channel(pl08x, plchan->phychan);
plchan->phychan = NULL;
}