On Wed, Jan 30, 2013 at 09:27:18AM +0000, Arnd Bergmann wrote:

On Wednesday 30 January 2013, Matt Porter wrote:

quoted

Adds a dma_request_slave_channel_compat() wrapper which accepts
both the arguments from dma_request_channel() and
dma_request_slave_channel(). Based on whether the driver is
instantiated via DT, the appropriate channel request call will be
made.

This allows for a much cleaner migration of drivers to the
dmaengine DT API as platforms continue to be mixed between those
that boot using DT and those that do not.

Suggested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Matt Porter <redacted>
Acked-by: Tony Lindgren <tony@atomide.com>

Acked-by: Arnd Bergmann <arnd@arndb.de>

quoted

@@ -1001,6 +1001,22 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
 struct dma_chan *net_dma_find_channel(void);
 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
+#define dma_request_slave_channel_compat(mask, x, y, dev, name) \
+	__dma_request_slave_channel_compat(&(mask), x, y, dev, name)
+
+static inline struct dma_chan
+*__dma_request_slave_channel_compat(dma_cap_mask_t *mask, dma_filter_fn fn,
+				  void *fn_param, struct device *dev,
+				  char *name)
+{
+	struct dma_chan *chan;
+
+	chan = dma_request_slave_channel(dev, name);
+	if (chan)
+		return chan;
+
+	return __dma_request_channel(mask, fn, fn_param);
+}

After I have spent some more time with implementing the code for dw_dma,
I think the mask is actually unnecessary here, the helper could just
always set it to DMA_SLAVE before calling __dma_request_channel.

It's not a bug to do it this way though, and it may help convert drivers
a little easier if there is less to change.

Agreed.

-Matt

	Arnd