| Message ID | 20161117125017.14954-2-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
Vinod, On 11/17/2016 02:50 PM, Peter Ujfalusi wrote: > Some slave devices uses address window instead of single register for read > and/or write of data. With the src/dst_port_window_size the address window > can be specified and the DMAengine driver should use this information to > correctly set up the transfer to loop within the provided window. > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > --- > include/linux/dmaengine.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index cc535a478bae..689d44327ef3 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -336,6 +336,12 @@ enum dma_slave_buswidth { > * may or may not be applicable on memory sources. > * @dst_maxburst: same as src_maxburst but for destination target > * mutatis mutandis. > + * @src_port_window_size: The length of the register area the data need to be > + * written on the device side. It is only used for devices which is using an > + * area instead of a single register to receive the data. Typically the DMA > + * loops in this area in order to transfer the data. > + * @dst_port_window_size: same as src_port_window_size but for the destination > + * port. I think this needs some clarification. Should the src/dst_port_window_size be in bytes or in words? I think it would make more sense to define it as number of words to be in sync with the src/dst_maxburst. I will need to resend the series either way. The omap-dma patch does not handle this correctly. > * @device_fc: Flow Controller Settings. Only valid for slave channels. Fill > * with 'true' if peripheral should be flow controller. Direction will be > * selected at Runtime. > @@ -363,6 +369,8 @@ struct dma_slave_config { > enum dma_slave_buswidth dst_addr_width; > u32 src_maxburst; > u32 dst_maxburst; > + u32 src_port_window_size; > + u32 dst_port_window_size; > bool device_fc; > unsigned int slave_id; > }; >
On Tue, Nov 29, 2016 at 12:47:48PM +0200, Peter Ujfalusi wrote: > Vinod, > > On 11/17/2016 02:50 PM, Peter Ujfalusi wrote: > > Some slave devices uses address window instead of single register for read > > and/or write of data. With the src/dst_port_window_size the address window > > can be specified and the DMAengine driver should use this information to > > correctly set up the transfer to loop within the provided window. > > > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > > --- > > include/linux/dmaengine.h | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > > index cc535a478bae..689d44327ef3 100644 > > --- a/include/linux/dmaengine.h > > +++ b/include/linux/dmaengine.h > > @@ -336,6 +336,12 @@ enum dma_slave_buswidth { > > * may or may not be applicable on memory sources. > > * @dst_maxburst: same as src_maxburst but for destination target > > * mutatis mutandis. > > + * @src_port_window_size: The length of the register area the data need to be > > + * written on the device side. It is only used for devices which is using an > > + * area instead of a single register to receive the data. Typically the DMA > > + * loops in this area in order to transfer the data. > > + * @dst_port_window_size: same as src_port_window_size but for the destination > > + * port. > > I think this needs some clarification. > Should the src/dst_port_window_size be in bytes or in words? I think it would > make more sense to define it as number of words to be in sync with the > src/dst_maxburst. Yes good catch, I would indeed prefer words here
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cc535a478bae..689d44327ef3 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -336,6 +336,12 @@ enum dma_slave_buswidth { * may or may not be applicable on memory sources. * @dst_maxburst: same as src_maxburst but for destination target * mutatis mutandis. + * @src_port_window_size: The length of the register area the data need to be + * written on the device side. It is only used for devices which is using an + * area instead of a single register to receive the data. Typically the DMA + * loops in this area in order to transfer the data. + * @dst_port_window_size: same as src_port_window_size but for the destination + * port. * @device_fc: Flow Controller Settings. Only valid for slave channels. Fill * with 'true' if peripheral should be flow controller. Direction will be * selected at Runtime. @@ -363,6 +369,8 @@ struct dma_slave_config { enum dma_slave_buswidth dst_addr_width; u32 src_maxburst; u32 dst_maxburst; + u32 src_port_window_size; + u32 dst_port_window_size; bool device_fc; unsigned int slave_id; };
Some slave devices uses address window instead of single register for read and/or write of data. With the src/dst_port_window_size the address window can be specified and the DMAengine driver should use this information to correctly set up the transfer to loop within the provided window. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> --- include/linux/dmaengine.h | 8 ++++++++ 1 file changed, 8 insertions(+)