On 16-06-21, 17:32, Vinod Koul wrote:

On 16-06-21, 12:35, Mark Brown wrote:

quoted

On Wed, Jun 16, 2021 at 02:20:45PM +0530, Vinod Koul wrote:

quoted

But in this case, that wont work. We have a parent qup device which is
the parent for both spi and dma device and needs to be used for
dma-mapping! 

quoted

If we allow drivers to set dma mapping device and use that, then I can
reuse the core. Let me know if that is agreeable to you and I can hack
this up. Maybe add a new member in spi_controller which is filled by
drivers in can_dma() callback?

Possibly, I'd need to see the code.

Ok, let me do a prototype and share ...

So setting the dma_map_dev in the can_dma() callback does not work as we
would need device before we invoke can_dma(), so modified this to be set
earlier by driver (in driver probe, set the dma_map_dev) and use in
__spi_map_msg().

With this it works for me & I was able to get rid of driver mapping code

-- >8 --

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index e353b7a9e54e..315f7e7545f7 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c

@@ -961,11 +961,15 @@ static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 
 	if (ctlr->dma_tx)
 		tx_dev = ctlr->dma_tx->device->dev;
+	else if (ctlr->dma_map_dev)
+		tx_dev = ctlr->dma_map_dev;
 	else
 		tx_dev = ctlr->dev.parent;
 
 	if (ctlr->dma_rx)
 		rx_dev = ctlr->dma_rx->device->dev;
+	else if (ctlr->dma_map_dev)
+		rx_dev = ctlr->dma_map_dev;
 	else
 		rx_dev = ctlr->dev.parent;
 

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 74239d65c7fd..4d3f116f5723 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h

@@ -586,6 +586,7 @@ struct spi_controller {
 	bool			(*can_dma)(struct spi_controller *ctlr,
 					   struct spi_device *spi,
 					   struct spi_transfer *xfer);
+	struct device *dma_map_dev;
 
 	/*
 	 * These hooks are for drivers that want to use the generic

-- 
~Vinod