Merge tag 'tegra-for-3.14-dmas-resets-rework' into drm/for-next

ARM: tegra: implement common DMA and resets DT bindings

This series converts the Tegra DTs and drivers to use the common/
standard DMA and reset bindings, rather than custom bindings. It also
adds complete documentation for the Tegra clock bindings without
actually changing any binding definitions.

This conversion relies on a few sets of patches in branches from outside
the Tegra tree:

1) A patch to add an DMA channel request API which allows deferred probe
   to be implemented.

2) A patch to implement a common part of the of_xlate function for DMA
   controllers.

3) Some ASoC patches (which in turn rely on (1) above), which support
   deferred probe during DMA channel allocation.

4) The Tegra clock driver changes for 3.14.

Consequently, this branch is based on a merge of all of those external
branches.

In turn, this branch is or will be pulled into a few places that either
rely on features introduced here, or would otherwise conflict with the
patches:

a) Tegra's own for-3.14/powergate and for-4.14/dt branches, to avoid
   conflicts.

b) The DRM tree, which introduces new code that relies on the reset
   controller framework introduced in this branch, and to avoid
   conflicts.

1 files changed, 59 insertions, 4 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index ea806bdc12ef..24095ff8a93b 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -535,11 +535,41 @@ struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
 }
 EXPORT_SYMBOL_GPL(dma_get_slave_channel);
 
+struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
+{
+        dma_cap_mask_t mask;
+        struct dma_chan *chan;
+        int err;
+
+        dma_cap_zero(mask);
+        dma_cap_set(DMA_SLAVE, mask);
+
+        /* lock against __dma_request_channel */
+        mutex_lock(&dma_list_mutex);
+
+        chan = private_candidate(&mask, device, NULL, NULL);
+        if (chan) {
+                err = dma_chan_get(chan);
+                if (err) {
+                        pr_debug("%s: failed to get %s: (%d)\n",
+                                __func__, dma_chan_name(chan), err);
+                        chan = NULL;
+                }
+        }
+
+        mutex_unlock(&dma_list_mutex);
+
+        return chan;
+}
+EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
+
 /**
  * __dma_request_channel - try to allocate an exclusive channel
  * @mask: capabilities that the channel must satisfy
  * @fn: optional callback to disposition available channels
  * @fn_param: opaque parameter to pass to dma_filter_fn
+ *
+ * Returns pointer to appropriate DMA channel on success or NULL.
  */
 struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
                                        dma_filter_fn fn, void *fn_param)
@@ -591,18 +621,43 @@ EXPORT_SYMBOL_GPL(__dma_request_channel);
  * dma_request_slave_channel - 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.
  */
-struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name)
+struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
+                                                  const char *name)
 {
+        struct dma_chan *chan;
+
         /* If device-tree is present get slave info from here */
         if (dev->of_node)
                 return of_dma_request_slave_channel(dev->of_node, name);
 
         /* If device was enumerated by ACPI get slave info from here */
-        if (ACPI_HANDLE(dev))
-                return acpi_dma_request_slave_chan_by_name(dev, name);
+        if (ACPI_HANDLE(dev)) {
+                chan = acpi_dma_request_slave_chan_by_name(dev, name);
+                if (chan)
+                        return chan;
+        }
 
-        return NULL;
+        return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
+
+/**
+ * dma_request_slave_channel - 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 NULL.
+ */
+struct dma_chan *dma_request_slave_channel(struct device *dev,
+                                           const char *name)
+{
+        struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
+        if (IS_ERR(ch))
+                return NULL;
+        return ch;
 }
 EXPORT_SYMBOL_GPL(dma_request_slave_channel);