[PATCH v2] ARM: EDMA: Fix clearing of unused list for DT DMA resources

[Joel Fernandes <joelf@ti.com>]

HWMOD removal for MMC is breaking edma_start as the events are being manually
triggered due to unused channel list not being clear, Thanks to Balaji TK for
finding this issue.

This patch fixes the issue, by reading the "dmas" property from the DT node if
it exists and clearing the bits in the unused channel list.

Cc: Balaji T K <balajitk@ti.com>
Cc: Pantel Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Joel Fernandes <joelf@ti.com>
---
v2 changes: Fixed compiler warning

 arch/arm/common/edma.c |   31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index a432e6c..765d578 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -561,14 +561,29 @@ static int reserve_contiguous_slots(int ctlr, unsigned int id,
 static int prepare_unused_channel_list(struct device *dev, void *data)
 {
 	struct platform_device *pdev = to_platform_device(dev);
-	int i, ctlr;
-
-	for (i = 0; i < pdev->num_resources; i++) {
-		if ((pdev->resource[i].flags & IORESOURCE_DMA) &&
-				(int)pdev->resource[i].start >= 0) {
-			ctlr = EDMA_CTLR(pdev->resource[i].start);
-			clear_bit(EDMA_CHAN_SLOT(pdev->resource[i].start),
-					edma_cc[ctlr]->edma_unused);
+	int i = 0, ctlr;
+	u32 dma_chan;
+	const __be32 *dma_chan_p;
+	struct property *prop;
+
+	if (dev->of_node) {
+		of_property_for_each_u32(dev->of_node, "dmas", prop, \
+					 dma_chan_p, dma_chan) {
+			if (i++ & 1) {
+				ctlr = EDMA_CTLR(dma_chan);
+				clear_bit(EDMA_CHAN_SLOT(dma_chan),
+						edma_cc[ctlr]->edma_unused);
+			}
+		}
+	} else {
+		for (; i < pdev->num_resources; i++) {
+			if ((pdev->resource[i].flags & IORESOURCE_DMA) &&
+			    (int)pdev->resource[i].start >= 0) {
+				ctlr = EDMA_CTLR(pdev->resource[i].start);
+				clear_bit(EDMA_CHAN_SLOT(
+					  pdev->resource[i].start),
+					  edma_cc[ctlr]->edma_unused);
+			}
 		}
 	}
 
-- 
1.7.9.5