[PATCH v2 2/2] dmaengine: fsl-edma: add edma src ID check at request channel

[Joy Zou <joy.zou@xxxxxxx>]

Check src ID to detect misuse of same src ID for multiple DMA channels.

Signed-off-by: Joy Zou <joy.zou@xxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/dma/fsl-edma-main.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
index d4f29ece69f5..f9f1eda79254 100644
--- a/drivers/dma/fsl-edma-main.c
+++ b/drivers/dma/fsl-edma-main.c
@@ -100,6 +100,22 @@ static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
 	return fsl_edma_err_handler(irq, dev_id);
 }
 
+static bool fsl_edma_srcid_in_use(struct fsl_edma_engine *fsl_edma, u32 srcid)
+{
+	struct fsl_edma_chan *fsl_chan;
+	int i;
+
+	for (i = 0; i < fsl_edma->n_chans; i++) {
+		fsl_chan = &fsl_edma->chans[i];
+
+		if (fsl_chan->srcid && srcid == fsl_chan->srcid) {
+			dev_err(&fsl_chan->pdev->dev, "The srcid is in use, can't use!");
+			return true;
+		}
+	}
+	return false;
+}
+
 static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
 		struct of_dma *ofdma)
 {
@@ -117,6 +133,10 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
 	list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) {
 		if (chan->client_count)
 			continue;
+
+		if (fsl_edma_srcid_in_use(fsl_edma, dma_spec->args[1]))
+			return NULL;
+
 		if ((chan->chan_id / chans_per_mux) == dma_spec->args[0]) {
 			chan = dma_get_slave_channel(chan);
 			if (chan) {
@@ -161,6 +181,8 @@ static struct dma_chan *fsl_edma3_xlate(struct of_phandle_args *dma_spec,
 			continue;
 
 		fsl_chan = to_fsl_edma_chan(chan);
+		if (fsl_edma_srcid_in_use(fsl_edma, dma_spec->args[0]))
+			return NULL;
 		i = fsl_chan - fsl_edma->chans;
 
 		fsl_chan->priority = dma_spec->args[1];
-- 
2.37.1