* [PATCH 1/2] spi: dt-bindings: cdns,xspi: add sdma-io-width
2026-05-11 3:17 [PATCH 0/2] spi: cadence-xspi: support 4bytes sdma-io-width Jisheng Zhang
@ 2026-05-11 3:17 ` Jisheng Zhang
2026-05-11 3:17 ` [PATCH 2/2] spi: cadence-xspi: support 4bytes sdma-io-width Jisheng Zhang
1 sibling, 0 replies; 3+ messages in thread
From: Jisheng Zhang @ 2026-05-11 3:17 UTC (permalink / raw)
To: Mark Brown, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: linux-spi, devicetree, linux-kernel
The cdns xspi controller SDMA data port may support wider I/O width.
Wider I/O width can benefit performance. A simple test with QSPI nor
flash on one arm64 platform:
1 byte io width (default):
# dd if=/dev/mtdblock0 of=/dev/null bs=8192 count=1000
1000+0 records in
1000+0 records out
8192000 bytes (7.8MB) copied, 1.368735 seconds, 5.7MB/s
4 bytes io width:
# dd if=/dev/mtdblock0 of=/dev/null bs=8192 count=1000
1000+0 records in
1000+0 records out
8192000 bytes (7.8MB) copied, 1.088787 seconds, 7.2MB/s
Improved by 26.3%!
Add dt binding for sdma-io-width.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
Documentation/devicetree/bindings/spi/cdns,xspi.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
index 38a5795589de..1fd4b6dfd417 100644
--- a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
+++ b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
@@ -40,6 +40,12 @@ properties:
interrupts:
maxItems: 1
+ sdma-io-width:
+ description: Slave DMA data port I/O width (in bytes)
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 1
+ enum: [ 1, 4 ]
+
required:
- compatible
- reg
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] spi: cadence-xspi: support 4bytes sdma-io-width
2026-05-11 3:17 [PATCH 0/2] spi: cadence-xspi: support 4bytes sdma-io-width Jisheng Zhang
2026-05-11 3:17 ` [PATCH 1/2] spi: dt-bindings: cdns,xspi: add sdma-io-width Jisheng Zhang
@ 2026-05-11 3:17 ` Jisheng Zhang
1 sibling, 0 replies; 3+ messages in thread
From: Jisheng Zhang @ 2026-05-11 3:17 UTC (permalink / raw)
To: Mark Brown, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: linux-spi, devicetree, linux-kernel
The cdns xspi controller SDMA data port may support wider I/O width.
Wider I/O width can benefit performance. A simple test with QSPI nor
flash on one arm64 platform:
1 byte io width (default):
# dd if=/dev/mtdblock0 of=/dev/null bs=8192 count=1000
1000+0 records in
1000+0 records out
8192000 bytes (7.8MB) copied, 1.368735 seconds, 5.7MB/s
4 bytes io width:
# dd if=/dev/mtdblock0 of=/dev/null bs=8192 count=1000
1000+0 records in
1000+0 records out
8192000 bytes (7.8MB) copied, 1.088787 seconds, 7.2MB/s
Improved by 26.3%!
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
drivers/spi/spi-cadence-xspi.c | 43 ++++++++++++++++++++++++++++++----
1 file changed, 39 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 895b4b3276a5..c1fb749540e7 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -369,6 +369,7 @@ struct cdns_xspi_dev {
void *in_buffer;
const void *out_buffer;
+ u32 sdma_io_width;
u8 hw_num_banks;
@@ -578,6 +579,38 @@ static int cdns_xspi_controller_init(struct cdns_xspi_dev *cdns_xspi)
return 0;
}
+static inline void cdns_xspi_sdma_read(struct cdns_xspi_dev *cdns_xspi, size_t len)
+{
+ void __iomem *src = cdns_xspi->sdmabase;
+ void *buf = cdns_xspi->in_buffer;
+ size_t offset = 0;
+
+ if (cdns_xspi->sdma_io_width == 4) {
+ if (IS_ALIGNED((uintptr_t)src, 4) && IS_ALIGNED((uintptr_t)buf, 4)) {
+ ioread32_rep(src, buf, len >> 2);
+ offset = len & ~0x3;
+ len -= offset;
+ }
+ }
+ ioread8_rep(src, (u8 *)buf + offset, len);
+}
+
+static inline void cdns_xspi_sdma_write(struct cdns_xspi_dev *cdns_xspi, size_t len)
+{
+ void __iomem *dst = cdns_xspi->sdmabase;
+ const void *buf = cdns_xspi->out_buffer;
+ size_t offset = 0;
+
+ if (cdns_xspi->sdma_io_width == 4) {
+ if (IS_ALIGNED((uintptr_t)dst, 4) && IS_ALIGNED((uintptr_t)buf, 4)) {
+ iowrite32_rep(dst, buf, len >> 2);
+ offset = len & ~0x3;
+ len -= offset;
+ }
+ }
+ iowrite8_rep(dst, (const u8 *)buf + offset, len);
+}
+
static void cdns_xspi_sdma_handle(struct cdns_xspi_dev *cdns_xspi)
{
u32 sdma_size, sdma_trd_info;
@@ -589,13 +622,11 @@ static void cdns_xspi_sdma_handle(struct cdns_xspi_dev *cdns_xspi)
switch (sdma_dir) {
case CDNS_XSPI_SDMA_DIR_READ:
- ioread8_rep(cdns_xspi->sdmabase,
- cdns_xspi->in_buffer, sdma_size);
+ cdns_xspi_sdma_read(cdns_xspi, sdma_size);
break;
case CDNS_XSPI_SDMA_DIR_WRITE:
- iowrite8_rep(cdns_xspi->sdmabase,
- cdns_xspi->out_buffer, sdma_size);
+ cdns_xspi_sdma_write(cdns_xspi, sdma_size);
break;
}
}
@@ -1215,6 +1246,10 @@ static int cdns_xspi_probe(struct platform_device *pdev)
}
}
+ if (device_property_read_u32(&pdev->dev, "sdma-io-width",
+ &cdns_xspi->sdma_io_width))
+ cdns_xspi->sdma_io_width = 1;
+
cdns_xspi->irq = platform_get_irq(pdev, 0);
if (cdns_xspi->irq < 0)
return -ENXIO;
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread