dmaengine: dw: provide DMA capabilities

The new DMAEngine requirement is to provide what the DMA controller can do,
such as directions, bus widths, and residue granularity. The patch sets those
properties for the DesignWare DMA controller driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/core.c

@@ -61,6 +61,13 @@
  */
 #define NR_DESCS_PER_CHANNEL	64
 
+/* The set of bus widths supported by the DMA controller */
+#define DW_DMA_BUSWIDTHS			  \
+	BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED)	| \
+	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)		| \
+	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES)		| \
+	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
+
 /*----------------------------------------------------------------------*/
 
 static struct device *chan2dev(struct dma_chan *chan)
@@ -1660,8 +1667,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 	dw->dma.device_free_chan_resources = dwc_free_chan_resources;
 
 	dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
-
 	dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
+
 	dw->dma.device_config = dwc_config;
 	dw->dma.device_pause = dwc_pause;
 	dw->dma.device_resume = dwc_resume;
@@ -1670,6 +1677,13 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 	dw->dma.device_tx_status = dwc_tx_status;
 	dw->dma.device_issue_pending = dwc_issue_pending;
 
+	/* DMA capabilities */
+	dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
+	dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
+	dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
+			     BIT(DMA_MEM_TO_MEM);
+	dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
 	err = dma_async_device_register(&dw->dma);
 	if (err)
 		goto err_dma_register;