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.com
Tested-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>

diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 403ade4..607647d 100644 (file)
--- 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 fdbbeda..7d8062e 100644 (file)
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -34,11 +34,20 @@ enum dw_edma_map_format {
 };
 
 /**
+ * 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;