1 files changed, 48 insertions, 14 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 491b22240221..ca13cd39330b 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -40,6 +40,8 @@
 #include <linux/dmaengine.h>
 #include <linux/hardirq.h>
 #include <linux/spinlock.h>
+#include <linux/of.h>
+#include <linux/property.h>
 #include <linux/percpu.h>
 #include <linux/rcupdate.h>
 #include <linux/mutex.h>
@@ -812,15 +814,13 @@ static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
  */
 struct dma_chan *dma_request_chan(struct device *dev, const char *name)
 {
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
 	struct dma_device *d, *_d;
 	struct dma_chan *chan = NULL;
 
-	/* If device-tree is present get slave info from here */
-	if (dev->of_node)
-		chan = of_dma_request_slave_channel(dev->of_node, name);
-
-	/* If device was enumerated by ACPI get slave info from here */
-	if (has_acpi_companion(dev) && !chan)
+	if (is_of_node(fwnode))
+		chan = of_dma_request_slave_channel(to_of_node(fwnode), name);
+	else if (is_acpi_device_node(fwnode))
 		chan = acpi_dma_request_slave_chan_by_name(dev, name);
 
 	if (PTR_ERR(chan) == -EPROBE_DEFER)
@@ -854,8 +854,8 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
 
 found:
 #ifdef CONFIG_DEBUG_FS
-	chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
-					  name);
+	chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), name);
+	/* No functional issue if it fails, users are supposed to test before use */
 #endif
 
 	chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
@@ -926,6 +926,36 @@ void dma_release_channel(struct dma_chan *chan)
 }
 EXPORT_SYMBOL_GPL(dma_release_channel);
 
+static void dmaenginem_release_channel(void *chan)
+{
+	dma_release_channel(chan);
+}
+
+/**
+ * devm_dma_request_chan - try to allocate an exclusive slave channel
+ * @dev:	pointer to client device structure
+ * @name:	slave channel name
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
+ *
+ * The operation is managed and will be undone on driver detach.
+ */
+
+struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)
+{
+	struct dma_chan *chan = dma_request_chan(dev, name);
+	int ret = 0;
+
+	if (!IS_ERR(chan))
+		ret = devm_add_action_or_reset(dev, dmaenginem_release_channel, chan);
+
+	if (ret)
+		return ERR_PTR(ret);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(devm_dma_request_chan);
+
 /**
  * dmaengine_get - register interest in dma_channels
  */
@@ -1037,7 +1067,8 @@ static int get_dma_id(struct dma_device *device)
 }
 
 static int __dma_async_device_channel_register(struct dma_device *device,
-					       struct dma_chan *chan)
+					       struct dma_chan *chan,
+					       const char *name)
 {
 	int rc;
 
@@ -1066,8 +1097,10 @@ static int __dma_async_device_channel_register(struct dma_device *device,
 	chan->dev->device.parent = device->dev;
 	chan->dev->chan = chan;
 	chan->dev->dev_id = device->dev_id;
-	dev_set_name(&chan->dev->device, "dma%dchan%d",
-		     device->dev_id, chan->chan_id);
+	if (!name)
+		dev_set_name(&chan->dev->device, "dma%dchan%d", device->dev_id, chan->chan_id);
+	else
+		dev_set_name(&chan->dev->device, "%s", name);
 	rc = device_register(&chan->dev->device);
 	if (rc)
 		goto err_out_ida;
@@ -1087,11 +1120,12 @@ static int __dma_async_device_channel_register(struct dma_device *device,
 }
 
 int dma_async_device_channel_register(struct dma_device *device,
-				      struct dma_chan *chan)
+				      struct dma_chan *chan,
+				      const char *name)
 {
 	int rc;
 
-	rc = __dma_async_device_channel_register(device, chan);
+	rc = __dma_async_device_channel_register(device, chan, name);
 	if (rc < 0)
 		return rc;
 
@@ -1203,7 +1237,7 @@ int dma_async_device_register(struct dma_device *device)
 
 	/* represent channels in sysfs. Probably want devs too */
 	list_for_each_entry(chan, &device->channels, device_node) {
-		rc = __dma_async_device_channel_register(device, chan);
+		rc = __dma_async_device_channel_register(device, chan, NULL);
 		if (rc < 0)
 			goto err_out;
 	}