dmaengine: dw-edma: Add support for chip-specific flags

Add a "flags" field to the "struct dw_edma_chip" so that the controller
drivers can pass flags that are relevant to the platform.

DW_EDMA_CHIP_LOCAL - Used by the controller drivers accessing eDMA
locally. Local eDMA access doesn't require generating MSIs to the remote.

Link: https://lore.kernel.org/r/20220524152159.2370739-8-Frank.Li@nxp.comTested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

drivers/dma/dw-edma/dw-edma-v0-core.c

@@ -301,6 +301,7 @@ u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
 static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
 {
 	struct dw_edma_burst *child;
+	struct dw_edma_chan *chan = chunk->chan;
 	struct dw_edma_v0_lli __iomem *lli;
 	struct dw_edma_v0_llp __iomem *llp;
 	u32 control = 0, i = 0;
@@ -314,9 +315,11 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
 	j = chunk->bursts_alloc;
 	list_for_each_entry(child, &chunk->burst->list, list) {
 		j--;
-		if (!j)
-			control |= (DW_EDMA_V0_LIE | DW_EDMA_V0_RIE);
-
+		if (!j) {
+			control |= DW_EDMA_V0_LIE;
+			if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL))
+				control |= DW_EDMA_V0_RIE;
+		}
 		/* Channel control */
 		SET_LL_32(&lli[i].control, control);
 		/* Transfer size */

include/linux/dma/edma.h

@@ -33,12 +33,21 @@ enum dw_edma_map_format {
 	EDMA_MF_HDMA_COMPAT = 0x5
 };
 
+/**
+ * enum dw_edma_chip_flags - Flags specific to an eDMA chip
+ * @DW_EDMA_CHIP_LOCAL:		eDMA is used locally by an endpoint
+ */
+enum dw_edma_chip_flags {
+	DW_EDMA_CHIP_LOCAL	= BIT(0),
+};
+
 /**
  * struct dw_edma_chip - representation of DesignWare eDMA controller hardware
  * @dev:		 struct device of the eDMA controller
  * @id:			 instance ID
  * @nr_irqs:		 total number of DMA IRQs
  * @ops			 DMA channel to IRQ number mapping
+ * @flags		 dw_edma_chip_flags
  * @reg_base		 DMA register base address
  * @ll_wr_cnt		 DMA write link list count
  * @ll_rd_cnt		 DMA read link list count
@@ -55,6 +64,7 @@ struct dw_edma_chip {
 	int			id;
 	int			nr_irqs;
 	const struct dw_edma_core_ops   *ops;
+	u32			flags;
 
 	void __iomem		*reg_base;