[PATCH v3 0/3] Add Agilex5 AXI DMA support

[PATCH v3 0/3] Add Agilex5 AXI DMA support

[Khairul Anuar Romli]

This series introduces support for Agilex5 SoC in the Synopsys DesignWare
AXI DMA binding and updates the device tree to use the platform-specific
compatible string.

The Agilex5 only has 40-bit DMA addressable bit instead of 64-bit. Hence,
this specific addition will enable driver to handle this limitation.

---
Notes:
This patch series is applied on socfpga maintainer's tree
https://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux.git/log/?h=socfpga_dts_for_v6.19

Changes in v3:
	- simplify dma-ranges addition without description as per input
	  from Rob.
	- Add simple-bus to with address-cells, size-cells, dma-ranges
	  added under this bus-node.
	- Move dma controller device node under simple-bus node.
	- Rename "arm64: dts: intel: agilex5: Add dma-ranges, address and size
	  cells to dma node" to #2
	- Drop "dt-bindings: dma: snps,dw-axi-dmac: Add #address-cells and
	  #size-cells"
	- Refactor "dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus
	  width" to align with dma controller node now under simple-bus node.

Changes in v2:
	- Add dma-ranges property.
	- Add address-cells and size-cells due to warning when dma-ranges
	  is define without address-cells and size-cells present. Also
	  prevent kernel panic if address-cells and size-cells are not
	  defined.
	- Add driver support to handle defined properties and set the DMA
	  BIT MASK according to value from DT.
	- Rename "arm64: dts: agilex5: Use platform-specific compatible for
          AXI DMA" to "arm64: dts: intel: agilex5: Add dma-ranges and
          address cells to dma node"

This changes is validated on:
	- intel/socfpga_agilex5_socdk.dtb
	- snps,dw-axi-dmac.yaml
	- snps,dw-axi-dmac.yaml intel/socfpga_agilex5_socdk.dtb
	- Agilex5 devkit
---
Khairul Anuar Romli (3):
  dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5
  arm64: dts: intel: agilex5: Add simple-bus node on top of dma
    controller node
  dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

 .../bindings/dma/snps,dw-axi-dmac.yaml        | 16 ++--
 .../arm64/boot/dts/intel/socfpga_agilex5.dtsi | 78 +++++++++++--------
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 +++++++++++++++-
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
 4 files changed, 124 insertions(+), 40 deletions(-)

-- 
2.43.7

[PATCH v3 1/3] dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

[Khairul Anuar Romli]

The address bus on Agilex5 is limited to 40 bits. When SMMU is enable this
will cause address truncation and translation faults. Hence introducing
"altr,agilex5-axi-dma" to enable platform specific configuration to
configure the dma addressable bit mask.

Add a fallback capability for the compatible property to allow driver to
probe and initialize with a newly added compatible string without requiring
additional entry in the driver.

Add dma-ranges to the binding schema to allow specifying DMA address
mapping between the controller and its parent bus.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
---
Changes in v3:
	- Simple dma-ranges property with true and without description
Changes in v2:
	- Add dma-ranges
---
 .../bindings/dma/snps,dw-axi-dmac.yaml           | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
index a393a33c8908..1f4dcf3092c3 100644
--- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
+++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
@@ -17,11 +17,15 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - snps,axi-dma-1.01a
-      - intel,kmb-axi-dma
-      - starfive,jh7110-axi-dma
-      - starfive,jh8100-axi-dma
+    oneOf:
+      - enum:
+          - snps,axi-dma-1.01a
+          - intel,kmb-axi-dma
+          - starfive,jh7110-axi-dma
+          - starfive,jh8100-axi-dma
+      - items:
+          - const: altr,agilex5-axi-dma
+          - const: snps,axi-dma-1.01a
 
   reg:
     minItems: 1
@@ -104,6 +108,8 @@ properties:
     minimum: 1
     maximum: 256
 
+  dma-ranges: true
+
 required:
   - compatible
   - reg
-- 
2.43.7

Re: [PATCH v3 1/3] dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

[Rob Herring]

On Thu, Dec 11, 2025 at 12:40:36PM +0800, Khairul Anuar Romli wrote:
> The address bus on Agilex5 is limited to 40 bits. When SMMU is enable this
> will cause address truncation and translation faults. Hence introducing
> "altr,agilex5-axi-dma" to enable platform specific configuration to
> configure the dma addressable bit mask.
> 
> Add a fallback capability for the compatible property to allow driver to
> probe and initialize with a newly added compatible string without requiring
> additional entry in the driver.
> 
> Add dma-ranges to the binding schema to allow specifying DMA address
> mapping between the controller and its parent bus.
> 
> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
> ---
> Changes in v3:
> 	- Simple dma-ranges property with true and without description
> Changes in v2:
> 	- Add dma-ranges
> ---
>  .../bindings/dma/snps,dw-axi-dmac.yaml           | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> index a393a33c8908..1f4dcf3092c3 100644
> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -17,11 +17,15 @@ allOf:
>  
>  properties:
>    compatible:
> -    enum:
> -      - snps,axi-dma-1.01a
> -      - intel,kmb-axi-dma
> -      - starfive,jh7110-axi-dma
> -      - starfive,jh8100-axi-dma
> +    oneOf:
> +      - enum:
> +          - snps,axi-dma-1.01a
> +          - intel,kmb-axi-dma
> +          - starfive,jh7110-axi-dma
> +          - starfive,jh8100-axi-dma
> +      - items:
> +          - const: altr,agilex5-axi-dma
> +          - const: snps,axi-dma-1.01a
>  
>    reg:
>      minItems: 1
> @@ -104,6 +108,8 @@ properties:
>      minimum: 1
>      maximum: 256
>  
> +  dma-ranges: true
> +

You no longer need this because it is in the bus node.

Rob

Re: [PATCH v3 1/3] dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

[Romli, Khairul Anuar]

On 11/12/2025 11:46 pm, Rob Herring wrote:
> On Thu, Dec 11, 2025 at 12:40:36PM +0800, Khairul Anuar Romli wrote:
>> The address bus on Agilex5 is limited to 40 bits. When SMMU is enable this
>> will cause address truncation and translation faults. Hence introducing
>> "altr,agilex5-axi-dma" to enable platform specific configuration to
>> configure the dma addressable bit mask.
>>
>> Add a fallback capability for the compatible property to allow driver to
>> probe and initialize with a newly added compatible string without requiring
>> additional entry in the driver.
>>
>> Add dma-ranges to the binding schema to allow specifying DMA address
>> mapping between the controller and its parent bus.
>>
>> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
>> ---
>> Changes in v3:
>> 	- Simple dma-ranges property with true and without description
>> Changes in v2:
>> 	- Add dma-ranges
>> ---
>>   .../bindings/dma/snps,dw-axi-dmac.yaml           | 16 +++++++++++-----
>>   1 file changed, 11 insertions(+), 5 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> index a393a33c8908..1f4dcf3092c3 100644
>> --- a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
>> @@ -17,11 +17,15 @@ allOf:
>>   
>>   properties:
>>     compatible:
>> -    enum:
>> -      - snps,axi-dma-1.01a
>> -      - intel,kmb-axi-dma
>> -      - starfive,jh7110-axi-dma
>> -      - starfive,jh8100-axi-dma
>> +    oneOf:
>> +      - enum:
>> +          - snps,axi-dma-1.01a
>> +          - intel,kmb-axi-dma
>> +          - starfive,jh7110-axi-dma
>> +          - starfive,jh8100-axi-dma
>> +      - items:
>> +          - const: altr,agilex5-axi-dma
>> +          - const: snps,axi-dma-1.01a
>>   
>>     reg:
>>       minItems: 1
>> @@ -104,6 +108,8 @@ properties:
>>       minimum: 1
>>       maximum: 256
>>   
>> +  dma-ranges: true
>> +
> 
> You no longer need this because it is in the bus node.
> 
> Rob

I will remove the dma-ranges property in the next revision.

Thanks.

Khairul

[PATCH v3 2/3] arm64: dts: intel: agilex5: Add simple-bus node on top of dma controller node

[Khairul Anuar Romli]

Move dma-controller node under simple-bus node to allow bus node specific
property able to be properly defined. This is require to fulfill Agilex5
bus limitation that is limited to 40-addressable-bit.

Update the compatible string for the DMA controller nodes in the Agilex5
device tree from the generic "snps,axi-dma-1.01a" to the platform-specific
"altr,agilex5-axi-dma". Add fallback capability to ensure driver is able
to initialize properly.

This change enables the use of platform-specific features and constraints
in the driver, such as setting a 40-bit DMA addressable mask through
dma-ranges, which is required for Agilex5. It also aligns with the updated
device tree bindings and driver support for this compatible string.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
---
Changes in v3:
	- Rename the patch  "arm64: dts: intel: agilex5: Add dma-ranges, address
	  and size cells to dma node"
	- Add simple-bus and move dmac0 and dmac1 1 level down.
Changes in v2:
	- Rename the from add platform specific to add dma-ranges, address
	  and size cells.
	- Define address-cells and size-cells for dmac0 and dmac1
	- Add dma-ranges for agilex5 for 40-bit
---
 .../arm64/boot/dts/intel/socfpga_agilex5.dtsi | 78 +++++++++++--------
 1 file changed, 44 insertions(+), 34 deletions(-)

diff --git a/arch/arm64/boot/dts/intel/socfpga_agilex5.dtsi b/arch/arm64/boot/dts/intel/socfpga_agilex5.dtsi
index 06f98667499b..bffd914cf051 100644
--- a/arch/arm64/boot/dts/intel/socfpga_agilex5.dtsi
+++ b/arch/arm64/boot/dts/intel/socfpga_agilex5.dtsi
@@ -335,40 +335,50 @@ ocram: sram@0 {
 			#size-cells = <1>;
 		};
 
-		dmac0: dma-controller@10db0000 {
-			compatible = "snps,axi-dma-1.01a";
-			reg = <0x10db0000 0x500>;
-			clocks = <&clkmgr AGILEX5_L4_MAIN_CLK>,
-				 <&clkmgr AGILEX5_L4_MP_CLK>;
-			clock-names = "core-clk", "cfgr-clk";
-			interrupt-parent = <&intc>;
-			interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>;
-			#dma-cells = <1>;
-			dma-channels = <4>;
-			snps,dma-masters = <1>;
-			snps,data-width = <2>;
-			snps,block-size = <32767 32767 32767 32767>;
-			snps,priority = <0 1 2 3>;
-			snps,axi-max-burst-len = <8>;
-			iommus = <&smmu 8>;
-		};
-
-		dmac1: dma-controller@10dc0000 {
-			compatible = "snps,axi-dma-1.01a";
-			reg = <0x10dc0000 0x500>;
-			clocks = <&clkmgr AGILEX5_L4_MAIN_CLK>,
-				 <&clkmgr AGILEX5_L4_MP_CLK>;
-			clock-names = "core-clk", "cfgr-clk";
-			interrupt-parent = <&intc>;
-			interrupts = <GIC_SPI 171 IRQ_TYPE_LEVEL_HIGH>;
-			#dma-cells = <1>;
-			dma-channels = <4>;
-			snps,dma-masters = <1>;
-			snps,data-width = <2>;
-			snps,block-size = <32767 32767 32767 32767>;
-			snps,priority = <0 1 2 3>;
-			snps,axi-max-burst-len = <8>;
-			iommus = <&smmu 9>;
+		dma: dma-bus@10db0000 {
+			compatible = "simple-bus";
+			#address-cells = <1>;
+			#size-cells = <2>;
+			ranges = <0x00 0x10db0000 0x00 0x20000>;
+			dma-ranges = <0x00 0x00 0x100 0x00>;
+
+			dmac0: dma-controller@0 {
+				compatible = "altr,agilex5-axi-dma",
+					     "snps,axi-dma-1.01a";
+				reg = <0x0 0x0 0x500>;
+				clocks = <&clkmgr AGILEX5_L4_MAIN_CLK>,
+					 <&clkmgr AGILEX5_L4_MP_CLK>;
+				clock-names = "core-clk", "cfgr-clk";
+				interrupt-parent = <&intc>;
+				interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>;
+				#dma-cells = <1>;
+				dma-channels = <4>;
+				snps,dma-masters = <1>;
+				snps,data-width = <2>;
+				snps,block-size = <32767 32767 32767 32767>;
+				snps,priority = <0 1 2 3>;
+				snps,axi-max-burst-len = <8>;
+				iommus = <&smmu 8>;
+			};
+
+			dmac1: dma-controller@10000 {
+				compatible = "altr,agilex5-axi-dma",
+					     "snps,axi-dma-1.01a";
+				reg = <0x10000 0x0 0x500>;
+				clocks = <&clkmgr AGILEX5_L4_MAIN_CLK>,
+					 <&clkmgr AGILEX5_L4_MP_CLK>;
+				clock-names = "core-clk", "cfgr-clk";
+				interrupt-parent = <&intc>;
+				interrupts = <GIC_SPI 171 IRQ_TYPE_LEVEL_HIGH>;
+				#dma-cells = <1>;
+				dma-channels = <4>;
+				snps,dma-masters = <1>;
+				snps,data-width = <2>;
+				snps,block-size = <32767 32767 32767 32767>;
+				snps,priority = <0 1 2 3>;
+				snps,axi-max-burst-len = <8>;
+				iommus = <&smmu 9>;
+			};
 		};
 
 		rst: rstmgr@10d11000 {
-- 
2.43.7

[PATCH v3 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

[Khairul Anuar Romli]

Add device tree compatible string support for the Altera Agilex5 AXI DMA
controller.

Introduces logic to parse the "dma-ranges" property and calculate the
actual number of addressable bits (bus width) for the DMA engine. This
calculated value is then used to set the coherent mask via
'dma_set_mask_and_coherent()', allowing the driver to correctly handle
devices with bus widths less than 64 bits. The addressable bits default to
64 if 'dma-ranges' is not specified or cannot be parsed.

Introduce 'addressable_bits' to 'struct axi_dma_chip' to store this value.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
---
Changes in v3:
	- Refactor the code to align with dma controller device node move
	  to 1 level down.
Changes in v2:
	- Add driver implementation to set the DMA BIT MAST to 40 based on
	  dma-ranges defined in DT.
	- Add glue for driver and DT.
---
 .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 ++++++++++++++++++-
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
 2 files changed, 69 insertions(+), 1 deletion(-)

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 b23536645ff7..96b0a0842ff5 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -271,7 +271,9 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
 		axi_chan_disable(&chip->dw->chan[i]);
 	}
-	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
+
+	dev_dbg(chip->dev, "Adressable bus width: %u\n", chip->addressable_bits);
+	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(chip->addressable_bits));
 	if (ret)
 		dev_warn(chip->dev, "Unable to set coherent mask\n");
 }
@@ -1461,13 +1463,24 @@ static int axi_req_irqs(struct platform_device *pdev, struct axi_dma_chip *chip)
 	return 0;
 }
 
+/* Forward declaration (no size required) */
+static const struct of_device_id dw_dma_of_id_table[];
+
 static int dw_probe(struct platform_device *pdev)
 {
 	struct axi_dma_chip *chip;
 	struct dw_axi_dma *dw;
 	struct dw_axi_dma_hcfg *hdata;
 	struct reset_control *resets;
+	struct device_node *parent;
+	const struct of_device_id *match;
 	unsigned int flags;
+	unsigned int addressable_bits = 64;
+	unsigned int len_bytes;
+	unsigned int num_cells;
+	const __be32 *prop;
+	u64 bus_width;
+	u32 *cells;
 	u32 i;
 	int ret;
 
@@ -1483,9 +1496,61 @@ static int dw_probe(struct platform_device *pdev)
 	if (!hdata)
 		return -ENOMEM;
 
+	match = of_match_node(dw_dma_of_id_table, pdev->dev.of_node);
+	if (!match) {
+		dev_err(&pdev->dev, "Unsupported AXI DMA device\n");
+		return -ENODEV;
+	}
+
+	parent = of_get_parent(pdev->dev.of_node);
+	if (parent) {
+		prop = of_get_property(parent, "dma-ranges", &len_bytes);
+		if (prop) {
+			num_cells = len_bytes / sizeof(__be32);
+			cells = kcalloc(num_cells, sizeof(*cells), GFP_KERNEL);
+			if (!cells)
+				return -ENOMEM;
+
+			ret = of_property_read_u32(parent, "#address-cells", &i);
+			if (ret) {
+				dev_err(&pdev->dev, "missing #address-cells property\n");
+				return ret;
+			}
+
+			ret = of_property_read_u32(parent, "#size-cells", &i);
+			if (ret) {
+				dev_err(&pdev->dev, "missing #size-cells property\n");
+				return ret;
+			}
+
+			if (!of_property_read_u32_array(parent, "dma-ranges",
+							cells, num_cells)) {
+				dev_dbg(&pdev->dev, "dma-ranges number of cells: %u\n", num_cells);
+				// Check if size-cells is 2 cells.
+				if (i == 2 && num_cells > 3) {
+					// Combine size cells into 64-bit length
+					dev_dbg(&pdev->dev, "size-cells MSB: %u\n",
+						cells[num_cells - 2]);
+					dev_dbg(&pdev->dev, "size-cells LSB: %u\n",
+						cells[num_cells - 1]);
+					bus_width = ((u64)cells[num_cells - 2] << 32) |
+cells[num_cells - 1];
+				}
+
+				// Count number of bits in bus_width
+				if (bus_width)
+					addressable_bits = fls64(bus_width) - 1;
+
+				dev_dbg(&pdev->dev, "Bus width: %u bits (length: 0x%llx)\n",
+					addressable_bits, bus_width);
+			}
+		}
+	}
+
 	chip->dw = dw;
 	chip->dev = &pdev->dev;
 	chip->dw->hdata = hdata;
+	chip->addressable_bits = addressable_bits;
 
 	chip->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(chip->regs))
@@ -1669,6 +1734,8 @@ static const struct of_device_id dw_dma_of_id_table[] = {
 	}, {
 		.compatible = "starfive,jh8100-axi-dma",
 		.data = (void *)AXI_DMA_FLAG_HAS_RESETS,
+	}, {
+		.compatible = "altr,agilex5-axi-dma"
 	},
 	{}
 };
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index b842e6a8d90d..f8152f8b3798 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -71,6 +71,7 @@ struct axi_dma_chip {
 	struct clk		*core_clk;
 	struct clk		*cfgr_clk;
 	struct dw_axi_dma	*dw;
+	u32			addressable_bits;
 };
 
 /* LLI == Linked List Item */
-- 
2.43.7

Re: [PATCH v3 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

[Rob Herring]

On Thu, Dec 11, 2025 at 12:40:38PM +0800, Khairul Anuar Romli wrote:
> Add device tree compatible string support for the Altera Agilex5 AXI DMA
> controller.
> 
> Introduces logic to parse the "dma-ranges" property and calculate the
> actual number of addressable bits (bus width) for the DMA engine. This
> calculated value is then used to set the coherent mask via
> 'dma_set_mask_and_coherent()', allowing the driver to correctly handle
> devices with bus widths less than 64 bits. The addressable bits default to
> 64 if 'dma-ranges' is not specified or cannot be parsed.
> 
> Introduce 'addressable_bits' to 'struct axi_dma_chip' to store this value.
> 
> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
> ---
> Changes in v3:
> 	- Refactor the code to align with dma controller device node move
> 	  to 1 level down.
> Changes in v2:
> 	- Add driver implementation to set the DMA BIT MAST to 40 based on
> 	  dma-ranges defined in DT.
> 	- Add glue for driver and DT.
> ---
>  .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 ++++++++++++++++++-
>  drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
>  2 files changed, 69 insertions(+), 1 deletion(-)
> 
> 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 b23536645ff7..96b0a0842ff5 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -271,7 +271,9 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
>  		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
>  		axi_chan_disable(&chip->dw->chan[i]);
>  	}
> -	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
> +
> +	dev_dbg(chip->dev, "Adressable bus width: %u\n", chip->addressable_bits);
> +	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(chip->addressable_bits));
>  	if (ret)
>  		dev_warn(chip->dev, "Unable to set coherent mask\n");
>  }
> @@ -1461,13 +1463,24 @@ static int axi_req_irqs(struct platform_device *pdev, struct axi_dma_chip *chip)
>  	return 0;
>  }
>  
> +/* Forward declaration (no size required) */
> +static const struct of_device_id dw_dma_of_id_table[];
> +
>  static int dw_probe(struct platform_device *pdev)
>  {
>  	struct axi_dma_chip *chip;
>  	struct dw_axi_dma *dw;
>  	struct dw_axi_dma_hcfg *hdata;
>  	struct reset_control *resets;
> +	struct device_node *parent;
> +	const struct of_device_id *match;
>  	unsigned int flags;
> +	unsigned int addressable_bits = 64;
> +	unsigned int len_bytes;
> +	unsigned int num_cells;
> +	const __be32 *prop;
> +	u64 bus_width;
> +	u32 *cells;
>  	u32 i;
>  	int ret;
>  
> @@ -1483,9 +1496,61 @@ static int dw_probe(struct platform_device *pdev)
>  	if (!hdata)
>  		return -ENOMEM;
>  
> +	match = of_match_node(dw_dma_of_id_table, pdev->dev.of_node);
> +	if (!match) {
> +		dev_err(&pdev->dev, "Unsupported AXI DMA device\n");
> +		return -ENODEV;
> +	}
> +
> +	parent = of_get_parent(pdev->dev.of_node);
> +	if (parent) {
> +		prop = of_get_property(parent, "dma-ranges", &len_bytes);
> +		if (prop) {
> +			num_cells = len_bytes / sizeof(__be32);
> +			cells = kcalloc(num_cells, sizeof(*cells), GFP_KERNEL);
> +			if (!cells)
> +				return -ENOMEM;
> +
> +			ret = of_property_read_u32(parent, "#address-cells", &i);
> +			if (ret) {
> +				dev_err(&pdev->dev, "missing #address-cells property\n");
> +				return ret;
> +			}
> +
> +			ret = of_property_read_u32(parent, "#size-cells", &i);
> +			if (ret) {
> +				dev_err(&pdev->dev, "missing #size-cells property\n");
> +				return ret;
> +			}
> +
> +			if (!of_property_read_u32_array(parent, "dma-ranges",
> +							cells, num_cells)) {

We have common code to parse dma-ranges. Use it and don't implement your 
own.

Rob

Re: [PATCH v3 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

[Rob Herring]

On Thu, Dec 11, 2025 at 9:45 AM Rob Herring <robh@kernel.org> wrote:
>
> On Thu, Dec 11, 2025 at 12:40:38PM +0800, Khairul Anuar Romli wrote:
> > Add device tree compatible string support for the Altera Agilex5 AXI DMA
> > controller.
> >
> > Introduces logic to parse the "dma-ranges" property and calculate the
> > actual number of addressable bits (bus width) for the DMA engine. This
> > calculated value is then used to set the coherent mask via
> > 'dma_set_mask_and_coherent()', allowing the driver to correctly handle
> > devices with bus widths less than 64 bits. The addressable bits default to
> > 64 if 'dma-ranges' is not specified or cannot be parsed.
> >
> > Introduce 'addressable_bits' to 'struct axi_dma_chip' to store this value.
> >
> > Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
> > ---
> > Changes in v3:
> >       - Refactor the code to align with dma controller device node move
> >         to 1 level down.
> > Changes in v2:
> >       - Add driver implementation to set the DMA BIT MAST to 40 based on
> >         dma-ranges defined in DT.
> >       - Add glue for driver and DT.
> > ---
> >  .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 ++++++++++++++++++-
> >  drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
> >  2 files changed, 69 insertions(+), 1 deletion(-)
> >
> > 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 b23536645ff7..96b0a0842ff5 100644
> > --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> > +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> > @@ -271,7 +271,9 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
> >               axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
> >               axi_chan_disable(&chip->dw->chan[i]);
> >       }
> > -     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
> > +
> > +     dev_dbg(chip->dev, "Adressable bus width: %u\n", chip->addressable_bits);
> > +     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(chip->addressable_bits));
> >       if (ret)
> >               dev_warn(chip->dev, "Unable to set coherent mask\n");
> >  }
> > @@ -1461,13 +1463,24 @@ static int axi_req_irqs(struct platform_device *pdev, struct axi_dma_chip *chip)
> >       return 0;
> >  }
> >
> > +/* Forward declaration (no size required) */
> > +static const struct of_device_id dw_dma_of_id_table[];
> > +
> >  static int dw_probe(struct platform_device *pdev)
> >  {
> >       struct axi_dma_chip *chip;
> >       struct dw_axi_dma *dw;
> >       struct dw_axi_dma_hcfg *hdata;
> >       struct reset_control *resets;
> > +     struct device_node *parent;
> > +     const struct of_device_id *match;
> >       unsigned int flags;
> > +     unsigned int addressable_bits = 64;
> > +     unsigned int len_bytes;
> > +     unsigned int num_cells;
> > +     const __be32 *prop;
> > +     u64 bus_width;
> > +     u32 *cells;
> >       u32 i;
> >       int ret;
> >
> > @@ -1483,9 +1496,61 @@ static int dw_probe(struct platform_device *pdev)
> >       if (!hdata)
> >               return -ENOMEM;
> >
> > +     match = of_match_node(dw_dma_of_id_table, pdev->dev.of_node);
> > +     if (!match) {
> > +             dev_err(&pdev->dev, "Unsupported AXI DMA device\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     parent = of_get_parent(pdev->dev.of_node);
> > +     if (parent) {
> > +             prop = of_get_property(parent, "dma-ranges", &len_bytes);
> > +             if (prop) {
> > +                     num_cells = len_bytes / sizeof(__be32);
> > +                     cells = kcalloc(num_cells, sizeof(*cells), GFP_KERNEL);
> > +                     if (!cells)
> > +                             return -ENOMEM;
> > +
> > +                     ret = of_property_read_u32(parent, "#address-cells", &i);
> > +                     if (ret) {
> > +                             dev_err(&pdev->dev, "missing #address-cells property\n");
> > +                             return ret;
> > +                     }
> > +
> > +                     ret = of_property_read_u32(parent, "#size-cells", &i);
> > +                     if (ret) {
> > +                             dev_err(&pdev->dev, "missing #size-cells property\n");
> > +                             return ret;
> > +                     }
> > +
> > +                     if (!of_property_read_u32_array(parent, "dma-ranges",
> > +                                                     cells, num_cells)) {
>
> We have common code to parse dma-ranges. Use it and don't implement your
> own.

Actually, the driver and DT core should take care of all this for you
and there's nothing to do in the driver. A driver only needs to set
the mask for the IP itself and only when >32 bits. The core takes care
of any additional restrictions in the bus.

Rob

Re: [PATCH v3 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

[Romli, Khairul Anuar]

On 11/12/2025 11:52 pm, Rob Herring wrote:
> On Thu, Dec 11, 2025 at 9:45 AM Rob Herring <robh@kernel.org> wrote:
>>
>> On Thu, Dec 11, 2025 at 12:40:38PM +0800, Khairul Anuar Romli wrote:
>>> Add device tree compatible string support for the Altera Agilex5 AXI DMA
>>> controller.
>>>
>>> Introduces logic to parse the "dma-ranges" property and calculate the
>>> actual number of addressable bits (bus width) for the DMA engine. This
>>> calculated value is then used to set the coherent mask via
>>> 'dma_set_mask_and_coherent()', allowing the driver to correctly handle
>>> devices with bus widths less than 64 bits. The addressable bits default to
>>> 64 if 'dma-ranges' is not specified or cannot be parsed.
>>>
>>> Introduce 'addressable_bits' to 'struct axi_dma_chip' to store this value.
>>>
>>> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
>>> ---
>>> Changes in v3:
>>>        - Refactor the code to align with dma controller device node move
>>>          to 1 level down.
>>> Changes in v2:
>>>        - Add driver implementation to set the DMA BIT MAST to 40 based on
>>>          dma-ranges defined in DT.
>>>        - Add glue for driver and DT.
>>> ---
>>>   .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 ++++++++++++++++++-
>>>   drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
>>>   2 files changed, 69 insertions(+), 1 deletion(-)
>>>
>>> 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 b23536645ff7..96b0a0842ff5 100644
>>> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>>> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>>> @@ -271,7 +271,9 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
>>>                axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
>>>                axi_chan_disable(&chip->dw->chan[i]);
>>>        }
>>> -     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
>>> +
>>> +     dev_dbg(chip->dev, "Adressable bus width: %u\n", chip->addressable_bits);
>>> +     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(chip->addressable_bits));
>>>        if (ret)
>>>                dev_warn(chip->dev, "Unable to set coherent mask\n");
>>>   }
>>> @@ -1461,13 +1463,24 @@ static int axi_req_irqs(struct platform_device *pdev, struct axi_dma_chip *chip)
>>>        return 0;
>>>   }
>>>
>>> +/* Forward declaration (no size required) */
>>> +static const struct of_device_id dw_dma_of_id_table[];
>>> +
>>>   static int dw_probe(struct platform_device *pdev)
>>>   {
>>>        struct axi_dma_chip *chip;
>>>        struct dw_axi_dma *dw;
>>>        struct dw_axi_dma_hcfg *hdata;
>>>        struct reset_control *resets;
>>> +     struct device_node *parent;
>>> +     const struct of_device_id *match;
>>>        unsigned int flags;
>>> +     unsigned int addressable_bits = 64;
>>> +     unsigned int len_bytes;
>>> +     unsigned int num_cells;
>>> +     const __be32 *prop;
>>> +     u64 bus_width;
>>> +     u32 *cells;
>>>        u32 i;
>>>        int ret;
>>>
>>> @@ -1483,9 +1496,61 @@ static int dw_probe(struct platform_device *pdev)
>>>        if (!hdata)
>>>                return -ENOMEM;
>>>
>>> +     match = of_match_node(dw_dma_of_id_table, pdev->dev.of_node);
>>> +     if (!match) {
>>> +             dev_err(&pdev->dev, "Unsupported AXI DMA device\n");
>>> +             return -ENODEV;
>>> +     }
>>> +
>>> +     parent = of_get_parent(pdev->dev.of_node);
>>> +     if (parent) {
>>> +             prop = of_get_property(parent, "dma-ranges", &len_bytes);
>>> +             if (prop) {
>>> +                     num_cells = len_bytes / sizeof(__be32);
>>> +                     cells = kcalloc(num_cells, sizeof(*cells), GFP_KERNEL);
>>> +                     if (!cells)
>>> +                             return -ENOMEM;
>>> +
>>> +                     ret = of_property_read_u32(parent, "#address-cells", &i);
>>> +                     if (ret) {
>>> +                             dev_err(&pdev->dev, "missing #address-cells property\n");
>>> +                             return ret;
>>> +                     }
>>> +
>>> +                     ret = of_property_read_u32(parent, "#size-cells", &i);
>>> +                     if (ret) {
>>> +                             dev_err(&pdev->dev, "missing #size-cells property\n");
>>> +                             return ret;
>>> +                     }
>>> +
>>> +                     if (!of_property_read_u32_array(parent, "dma-ranges",
>>> +                                                     cells, num_cells)) {
>>
>> We have common code to parse dma-ranges. Use it and don't implement your
>> own.
> 
> Actually, the driver and DT core should take care of all this for you
> and there's nothing to do in the driver. A driver only needs to set
> the mask for the IP itself and only when >32 bits. The core takes care
> of any additional restrictions in the bus.
> 
> Rob

The current implementation explicitly set the mask to 64.

-     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));

Will the core re-set the mask based on the dma-ranges on DT?

Thanks.

Regards,
Khairul

Re: [PATCH v3 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

[Rob Herring]

On Thu, Dec 11, 2025 at 6:46 PM Romli, Khairul Anuar
<khairul.anuar.romli@altera.com> wrote:
>
> On 11/12/2025 11:52 pm, Rob Herring wrote:
> > On Thu, Dec 11, 2025 at 9:45 AM Rob Herring <robh@kernel.org> wrote:
> >>
> >> On Thu, Dec 11, 2025 at 12:40:38PM +0800, Khairul Anuar Romli wrote:
> >>> Add device tree compatible string support for the Altera Agilex5 AXI DMA
> >>> controller.
> >>>
> >>> Introduces logic to parse the "dma-ranges" property and calculate the
> >>> actual number of addressable bits (bus width) for the DMA engine. This
> >>> calculated value is then used to set the coherent mask via
> >>> 'dma_set_mask_and_coherent()', allowing the driver to correctly handle
> >>> devices with bus widths less than 64 bits. The addressable bits default to
> >>> 64 if 'dma-ranges' is not specified or cannot be parsed.
> >>>
> >>> Introduce 'addressable_bits' to 'struct axi_dma_chip' to store this value.
> >>>
> >>> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
> >>> ---
> >>> Changes in v3:
> >>>        - Refactor the code to align with dma controller device node move
> >>>          to 1 level down.
> >>> Changes in v2:
> >>>        - Add driver implementation to set the DMA BIT MAST to 40 based on
> >>>          dma-ranges defined in DT.
> >>>        - Add glue for driver and DT.
> >>> ---
> >>>   .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 69 ++++++++++++++++++-
> >>>   drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
> >>>   2 files changed, 69 insertions(+), 1 deletion(-)
> >>>
> >>> 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 b23536645ff7..96b0a0842ff5 100644
> >>> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> >>> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> >>> @@ -271,7 +271,9 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
> >>>                axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
> >>>                axi_chan_disable(&chip->dw->chan[i]);
> >>>        }
> >>> -     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
> >>> +
> >>> +     dev_dbg(chip->dev, "Adressable bus width: %u\n", chip->addressable_bits);
> >>> +     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(chip->addressable_bits));
> >>>        if (ret)
> >>>                dev_warn(chip->dev, "Unable to set coherent mask\n");
> >>>   }
> >>> @@ -1461,13 +1463,24 @@ static int axi_req_irqs(struct platform_device *pdev, struct axi_dma_chip *chip)
> >>>        return 0;
> >>>   }
> >>>
> >>> +/* Forward declaration (no size required) */
> >>> +static const struct of_device_id dw_dma_of_id_table[];
> >>> +
> >>>   static int dw_probe(struct platform_device *pdev)
> >>>   {
> >>>        struct axi_dma_chip *chip;
> >>>        struct dw_axi_dma *dw;
> >>>        struct dw_axi_dma_hcfg *hdata;
> >>>        struct reset_control *resets;
> >>> +     struct device_node *parent;
> >>> +     const struct of_device_id *match;
> >>>        unsigned int flags;
> >>> +     unsigned int addressable_bits = 64;
> >>> +     unsigned int len_bytes;
> >>> +     unsigned int num_cells;
> >>> +     const __be32 *prop;
> >>> +     u64 bus_width;
> >>> +     u32 *cells;
> >>>        u32 i;
> >>>        int ret;
> >>>
> >>> @@ -1483,9 +1496,61 @@ static int dw_probe(struct platform_device *pdev)
> >>>        if (!hdata)
> >>>                return -ENOMEM;
> >>>
> >>> +     match = of_match_node(dw_dma_of_id_table, pdev->dev.of_node);
> >>> +     if (!match) {
> >>> +             dev_err(&pdev->dev, "Unsupported AXI DMA device\n");
> >>> +             return -ENODEV;
> >>> +     }
> >>> +
> >>> +     parent = of_get_parent(pdev->dev.of_node);
> >>> +     if (parent) {
> >>> +             prop = of_get_property(parent, "dma-ranges", &len_bytes);
> >>> +             if (prop) {
> >>> +                     num_cells = len_bytes / sizeof(__be32);
> >>> +                     cells = kcalloc(num_cells, sizeof(*cells), GFP_KERNEL);
> >>> +                     if (!cells)
> >>> +                             return -ENOMEM;
> >>> +
> >>> +                     ret = of_property_read_u32(parent, "#address-cells", &i);
> >>> +                     if (ret) {
> >>> +                             dev_err(&pdev->dev, "missing #address-cells property\n");
> >>> +                             return ret;
> >>> +                     }
> >>> +
> >>> +                     ret = of_property_read_u32(parent, "#size-cells", &i);
> >>> +                     if (ret) {
> >>> +                             dev_err(&pdev->dev, "missing #size-cells property\n");
> >>> +                             return ret;
> >>> +                     }
> >>> +
> >>> +                     if (!of_property_read_u32_array(parent, "dma-ranges",
> >>> +                                                     cells, num_cells)) {
> >>
> >> We have common code to parse dma-ranges. Use it and don't implement your
> >> own.
> >
> > Actually, the driver and DT core should take care of all this for you
> > and there's nothing to do in the driver. A driver only needs to set
> > the mask for the IP itself and only when >32 bits. The core takes care
> > of any additional restrictions in the bus.
> >
> > Rob
>
> The current implementation explicitly set the mask to 64.
>
> -     ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
>
> Will the core re-set the mask based on the dma-ranges on DT?

I don't think it changes the mask, but there's also bus ranges which
get factored in. See struct device.bus_dma_limit and dma_range_map.

Rob