diff mbox

[v6,07/10] dmaengine: add dma_request_slave_channel_compat()

Message ID 1359529229-22207-8-git-send-email-mporter@ti.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Matt Porter Jan. 30, 2013, 7 a.m. UTC
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 <mporter@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
---
 include/linux/dmaengine.h |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Arnd Bergmann Jan. 30, 2013, 9:27 a.m. UTC | #1
On Wednesday 30 January 2013, Matt Porter wrote:
> 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 <mporter@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>

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

> @@ -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.

	Arnd
Matt Porter Jan. 31, 2013, 1:38 a.m. UTC | #2
On Wed, Jan 30, 2013 at 09:27:18AM +0000, Arnd Bergmann wrote:
> On Wednesday 30 January 2013, Matt Porter wrote:
> > 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 <mporter@ti.com>
> > Acked-by: Tony Lindgren <tony@atomide.com>
> 
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> 
> > @@ -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
diff mbox

Patch

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index bfcdecb..17d8ffd 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -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);
+}
 
 /* --- Helper iov-locking functions --- */