[PATCH 7/7] dw_dmac.c: Pass Channel Allocation Priority from platform_data

[Viresh Kumar]

From: Viresh KUMAR <viresh.kumar@xxxxxx>

In SPEAr Platform channels 4-7 have more Fifo depth. So we must get better
channel first. This patch introduces concept of channel allocation priority in
dw_dmac. If user doesn't paas anything or 0, than normal (ascending) channel
allocation will follow, else channels will be allocated in descending order.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxx>
---
 drivers/dma/dw_dmac.c   |    6 +++++-
 include/linux/dw_dmac.h |    3 +++
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 01f783d..d4bf956 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1314,7 +1314,11 @@ static int __init dw_probe(struct platform_device *pdev)
 		dwc->chan.device = &dw->dma;
 		dwc->chan.cookie = dwc->completed = 1;
 		dwc->chan.chan_id = i;
-		list_add_tail(&dwc->chan.device_node, &dw->dma.channels);
+		if (pdata->chan_priority == CHAN_PRIO_ASCENDING)
+			list_add_tail(&dwc->chan.device_node,
+					&dw->dma.channels);
+		else
+			list_add(&dwc->chan.device_node, &dw->dma.channels);
 
 		dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
 		spin_lock_init(&dwc->lock);
diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h
index c8aad71..b1ab0b9 100644
--- a/include/linux/dw_dmac.h
+++ b/include/linux/dw_dmac.h
@@ -19,6 +19,9 @@
  */
 struct dw_dma_platform_data {
 	unsigned int	nr_channels;
+#define CHAN_PRIO_ASCENDING	0	/* zero to seven */
+#define CHAN_PRIO_DESCENDING	1	/* seven to zero */
+	unsigned int	chan_priority;
 };
 
 /**
-- 
1.7.2.2

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