[PATCH v3 3/9] dmaengine: dw-axi-dmac: Use bus width capability helpers
From: Nuno Sá
Date: Mon Aug 31 2026 - 07:56:05 EST
Advertise the supported bus widths through dma_set_src_bus_widths()
and dma_set_dst_bus_widths() instead of assigning the legacy u32 masks
directly. This keeps the driver using the new bitmap representation
while preserving legacy fields during the transition.
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
---
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 38 +++++++++++++++-----------
1 file changed, 22 insertions(+), 16 deletions(-)
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index eebed2474210..ca0ab8dc5f59 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -10,6 +10,7 @@
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/dma/engine/widthmask.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
@@ -33,20 +34,6 @@
#include "../dmaengine.h"
#include "../virt-dma.h"
-/*
- * The set of bus widths supported by the DMA controller. DW AXI DMAC supports
- * master data bus width up to 512 bits (for both AXI master interfaces), but
- * it depends on IP block configuration.
- */
-#define AXI_DMA_BUSWIDTHS \
- (DMA_SLAVE_BUSWIDTH_1_BYTE | \
- DMA_SLAVE_BUSWIDTH_2_BYTES | \
- DMA_SLAVE_BUSWIDTH_4_BYTES | \
- DMA_SLAVE_BUSWIDTH_8_BYTES | \
- DMA_SLAVE_BUSWIDTH_16_BYTES | \
- DMA_SLAVE_BUSWIDTH_32_BYTES | \
- DMA_SLAVE_BUSWIDTH_64_BYTES)
-
#define AXI_DMA_FLAG_HAS_APB_REGS BIT(0)
#define AXI_DMA_FLAG_HAS_RESETS BIT(1)
#define AXI_DMA_FLAG_USE_CFG2 BIT(2)
@@ -1482,6 +1469,20 @@ static int dw_probe(struct platform_device *pdev)
unsigned int flags;
u32 i;
int ret;
+ /*
+ * The set of bus widths supported by the DMA controller. DW AXI DMAC
+ * supports master data bus width up to 512 bits (for both AXI master
+ * interfaces), but it depends on IP block configuration.
+ */
+ enum dma_slave_buswidth buswidths[] = {
+ DMA_SLAVE_BUSWIDTH_1_BYTE,
+ DMA_SLAVE_BUSWIDTH_2_BYTES,
+ DMA_SLAVE_BUSWIDTH_4_BYTES,
+ DMA_SLAVE_BUSWIDTH_8_BYTES,
+ DMA_SLAVE_BUSWIDTH_16_BYTES,
+ DMA_SLAVE_BUSWIDTH_32_BYTES,
+ DMA_SLAVE_BUSWIDTH_64_BYTES,
+ };
chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
@@ -1565,8 +1566,13 @@ static int dw_probe(struct platform_device *pdev)
/* DMA capabilities */
dw->dma.max_burst = hdata->axi_rw_burst_len;
- dw->dma.src_addr_widths = AXI_DMA_BUSWIDTHS;
- dw->dma.dst_addr_widths = AXI_DMA_BUSWIDTHS;
+ ret = dma_bus_width_set_many(dw->dma.src_bus_widths, buswidths, ARRAY_SIZE(buswidths));
+ if (ret)
+ return ret;
+
+ ret = dma_bus_width_set_many(dw->dma.dst_bus_widths, buswidths, ARRAY_SIZE(buswidths));
+ if (ret)
+ return ret;
dw->dma.directions = BIT(DMA_MEM_TO_MEM);
dw->dma.directions |= BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
--
2.55.0