[PATCH] DMA: let filter functions of of_dma_simple_xlate possible check of_node

[Richard Zhao]

pass of_phandle_args dma_spec to dma_request_channel in of_dma_simple_xlate,
so the filter function could access of_node in of_phandle_args.

It also remove restriction of #dma-cells has to be one.

Signed-off-by: Richard Zhao <rizhao at nvidia.com>
---
 drivers/dma/edma.c     |  7 +++++--
 drivers/dma/of-dma.c   | 10 ++++------
 drivers/dma/omap-dma.c |  6 ++++--
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 4f6d87b..54582fd 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/of_dma.h>
 
 #include <linux/platform_data/edma.h>
 
@@ -604,9 +605,11 @@ static struct platform_driver edma_driver = {
 
 bool edma_filter_fn(struct dma_chan *chan, void *param)
 {
-	if (chan->device->dev->driver == &edma_driver.driver) {
+	struct of_phandle_args *dma_spec = param;
+	if (chan->device->dev->driver == &edma_driver.driver &&
+			dma_spec->np == chan->device->dev->of_node) {
 		struct edma_chan *echan = to_edma_chan(chan);
-		unsigned ch_req = *(unsigned *)param;
+		unsigned ch_req = dma_spec->args[0];
 		return ch_req == echan->ch_num;
 	}
 	return false;
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 75334bd..e1c4d3b 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -192,11 +192,9 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
  * @dma_spec:	pointer to DMA specifier as found in the device tree
  * @of_dma:	pointer to DMA controller data
  *
- * A simple translation function for devices that use a 32-bit value for the
+ * A simple translation function for devices that use dma_spec for the
  * filter_param when calling the DMA engine dma_request_channel() function.
- * Note that this translation function requires that #dma-cells is equal to 1
- * and the argument of the dma specifier is the 32-bit filter_param. Returns
- * pointer to appropriate dma channel on success or NULL on error.
+ * Returns pointer to appropriate dma channel on success or NULL on error.
  */
 struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 						struct of_dma *ofdma)
@@ -207,10 +205,10 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 	if (!info || !info->filter_fn)
 		return NULL;
 
-	if (count != 1)
+	if (count < 1)
 		return NULL;
 
 	return dma_request_channel(info->dma_cap, info->filter_fn,
-			&dma_spec->args[0]);
+			dma_spec);
 }
 EXPORT_SYMBOL_GPL(of_dma_simple_xlate);
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index ec3fc4f..32547ec 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -693,9 +693,11 @@ static struct platform_driver omap_dma_driver = {
 
 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
 {
-	if (chan->device->dev->driver == &omap_dma_driver.driver) {
+	struct of_phandle_args *dma_spec = param;
+	if (chan->device->dev->driver == &omap_dma_driver.driver &&
+			dma_spec->np == chan->device->dev->of_node) {
 		struct omap_chan *c = to_omap_dma_chan(chan);
-		unsigned req = *(unsigned *)param;
+		unsigned req = dma_spec->args[0];
 
 		return req == c->dma_sig;
 	}
-- 
1.8.1.5