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

[joelf@ti.com (Joel Fernandes)]

HWMOD removal for MMC and Crypto is breaking edma_start as the events are
being manually triggered due to unused channel list not being clear. Atleast
breakage has been seen on these peripherals, but it is expected Audio (McASP)
maybe breaking too.

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 so that these channels
are not manually triggered.

v2 changes:
Reduced indendation by returning from if block.

Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Reported-by: Balaji T K <balajitk@ti.com>
Cc: Pantel Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Joel Fernandes <joelf@ti.com>
---
Note:
Patch should go in for -rc cycle as it fixes existing crypto drivers.

 arch/arm/common/edma.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 39ad030..3867e7e 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -560,14 +560,30 @@ 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;
+	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);
+			}
+		}
+		return;
+	}
 
-	for (i = 0; i < pdev->num_resources; i++) {
+	/* For non-OF case */
+	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);
+				  edma_cc[ctlr]->edma_unused);
 		}
 	}
 
-- 
1.8.1.2