spi: core: add dma_map_dev for dma device

Some controllers like qcom geni need the parent device to be used for
dma mapping, so add a dma_map_dev field and let drivers fill this to be
used as mapping device
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -993,11 +993,15 @@ 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;
 

include/linux/spi/spi.h

@@ -588,6 +588,7 @@ 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