[v5,7/9] dmaengine: dw-edma: Add support for chip specific flags

Commit Message

Frank Li March 10, 2022, 7:24 p.m. UTC

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.

Signed-off-by: Frank Li <[e-mail]>
---
Change from v4 to v5
 - split two two patch
 - rework commit message
Change from v3 to v4
none
Change from v2 to v3
 - rework commit message
 - Change to DW_EDMA_CHIP_32BIT_DBI
 - using DW_EDMA_CHIP_LOCAL control msi
 - Apply Bjorn's comments,
        if (!j) {
               control |= DW_EDMA_V0_LIE;
               if (!(chan->chip->flags & DW_EDMA_CHIP_LOCAL))
                               control |= DW_EDMA_V0_RIE;
        }

        if ((chan->chip->flags & DW_EDMA_CHIP_REG32BIT) ||
              !IS_ENABLED(CONFIG_64BIT)) {
          SET_CH_32(...);
          SET_CH_32(...);
       } else {
          SET_CH_64(...);
       }


Change from v1 to v2
- none

 drivers/dma/dw-edma/dw-edma-v0-core.c | 9 ++++++---
 include/linux/dma/edma.h              | 5 +++++
 2 files changed, 11 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 35f2adac93e46..30686bfe1790c 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/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 */
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index c2039246fc08c..5816c8bdf9a64 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -33,12 +33,16 @@  enum dw_edma_map_format {
 	EDMA_MF_HDMA_COMPAT = 0x5
 };
 
+/* Probe EDMA engine locally and prevent generate MSI to host side*/
+#define 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 dma irq number
  * @ops			 DMA channel to IRQ number mapping
+ * @flags		  - DW_EDMA_CHIP_LOCAL
  * @reg_base		 DMA register base address
  * @ll_wr_cnt		 DMA write link list number
  * @ll_rd_cnt		 DMA read link list number
@@ -53,6 +57,7 @@  struct dw_edma_chip {
 	int			id;
 	int			nr_irqs;
 	const struct dw_edma_core_ops   *ops;
+	u32			flags;
 
 	void __iomem		*reg_base;