[PATCH 0/4] dmaengine: sh: rcar-dmac: add R-Car Gen5 X5H support

[PATCH 0/4] dmaengine: sh: rcar-dmac: add R-Car Gen5 X5H support

[Wolfram Sang]

Here is a small series with the needed driver updates to support R-Car
Gen5 and X5H for the SYSC-DMAC. Details are in the patch descriptions,
but it is all small stuff.

It has been tested on an Ironhide board (X5H) and a SparrowHawk (V4H)
for regression testing. The testing branch can be found here:

git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git renesas/x5h/i2c-experimental

The patches here are based on linux-next as of 20260825. DT checks have
also been passed.

Looking forward to comments or approval!


Wolfram Sang (4):
  dmaengine: sh: rcar-dmac: fix style in struct initialization
  dmaengine: sh: rcar-dmac: SMMU doesn't need IPMMU workaround
  dt-bindings: renesas,rcar-dmac: Add support for R-Car X5H SoC
  dmaengine: sh: rcar-dmac: Add support for R-Car Gen5 SoCs

 .../bindings/dma/renesas,rcar-dmac.yaml       |  6 +++++
 drivers/dma/sh/rcar-dmac.c                    | 25 ++++++++++++++-----
 2 files changed, 25 insertions(+), 6 deletions(-)

-- 
2.47.3

[PATCH 1/4] dmaengine: sh: rcar-dmac: fix style in struct initialization

[Wolfram Sang]

A new member will be added to the struct. Before that, adhere to coding
style by using a single space when assigning values.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/dma/sh/rcar-dmac.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 44eab2d21d54..cf07c17847d0 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1998,13 +1998,13 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 }
 
 static const struct rcar_dmac_of_data rcar_dmac_data = {
-	.chan_offset_base	= 0x8000,
-	.chan_offset_stride	= 0x80,
+	.chan_offset_base = 0x8000,
+	.chan_offset_stride = 0x80,
 };
 
 static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
-	.chan_offset_base	= 0x0,
-	.chan_offset_stride	= 0x1000,
+	.chan_offset_base = 0x0,
+	.chan_offset_stride = 0x1000,
 };
 
 static const struct of_device_id rcar_dmac_of_ids[] = {
-- 
2.47.3

[PATCH 2/4] dmaengine: sh: rcar-dmac: SMMU doesn't need IPMMU workaround

[Wolfram Sang]

R-Car Gen5 doesn't use an IPMMU anymore, but a SMMU. So, the workaround
for the IPMMU becomes optional. Add a flag to distinguish. No functional
change.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/dma/sh/rcar-dmac.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index cf07c17847d0..9c5210257097 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -219,10 +219,12 @@ struct rcar_dmac {
  * struct rcar_dmac_of_data - This driver's OF data
  * @chan_offset_base: DMAC channels base offset
  * @chan_offset_stride: DMAC channels offset stride
+ * @has_ipmmu: flag telling if DMAC is connected to an IPMMU
  */
 struct rcar_dmac_of_data {
 	u32 chan_offset_base;
 	u32 chan_offset_stride;
+	unsigned int has_ipmmu:1;
 };
 
 /* -----------------------------------------------------------------------------
@@ -1877,8 +1879,9 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	 * can't use it with the IPMMU. As the IOMMU API operates at the device
 	 * level we can't disable it selectively, so ignore channel 0 for now if
 	 * the device is part of an IOMMU group.
+	 * Not applicable if system uses something else than IPMMU like SMMU.
 	 */
-	if (device_iommu_mapped(&pdev->dev))
+	if (data->has_ipmmu && device_iommu_mapped(&pdev->dev))
 		dmac->channels_mask &= ~BIT(0);
 
 	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
@@ -2000,11 +2003,13 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 static const struct rcar_dmac_of_data rcar_dmac_data = {
 	.chan_offset_base = 0x8000,
 	.chan_offset_stride = 0x80,
+	.has_ipmmu = 1,
 };
 
 static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
 	.chan_offset_base = 0x0,
 	.chan_offset_stride = 0x1000,
+	.has_ipmmu = 1,
 };
 
 static const struct of_device_id rcar_dmac_of_ids[] = {
-- 
2.47.3

[PATCH 3/4] dt-bindings: renesas,rcar-dmac: Add support for R-Car X5H SoC

[Wolfram Sang]

Also add the familiy compatible because X5H is the first R-Car Gen5 SoC.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 .../devicetree/bindings/dma/renesas,rcar-dmac.yaml          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml
index 04fc4a99a7cb..d3d521c927e1 100644
--- a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml
+++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml
@@ -49,6 +49,11 @@ properties:
               - renesas,dmac-r8a779h0     # R-Car V4M
           - const: renesas,rcar-gen4-dmac # R-Car Gen4
 
+      - items:
+          - enum:
+              - renesas,dmac-r8a78000     # R-Car X5H
+          - const: renesas,rcar-gen5-dmac # R-Car Gen5
+
   reg: true
 
   interrupts:
@@ -123,6 +128,7 @@ if:
       contains:
         enum:
           - renesas,rcar-gen4-dmac
+          - renesas,rcar-gen5-dmac
 then:
   properties:
     reg:
-- 
2.47.3

[PATCH 4/4] dmaengine: sh: rcar-dmac: Add support for R-Car Gen5 SoCs

[Wolfram Sang]

Gen5 is very similar to Gen4. Of interest here is that it has a SMMU
instead of an IPMMU, so we don't need to set the flag for a workaround.
Make the module description more generic while here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/dma/sh/rcar-dmac.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 9c5210257097..06f691f5f3fb 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -2012,6 +2012,11 @@ static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
 	.has_ipmmu = 1,
 };
 
+static const struct rcar_dmac_of_data rcar_gen5_dmac_data = {
+	.chan_offset_base = 0x0,
+	.chan_offset_stride = 0x1000,
+};
+
 static const struct of_device_id rcar_dmac_of_ids[] = {
 	{
 		.compatible = "renesas,rcar-dmac",
@@ -2019,6 +2024,9 @@ static const struct of_device_id rcar_dmac_of_ids[] = {
 	}, {
 		.compatible = "renesas,rcar-gen4-dmac",
 		.data = &rcar_gen4_dmac_data,
+	}, {
+		.compatible = "renesas,rcar-gen5-dmac",
+		.data = &rcar_gen5_dmac_data,
 	}, {
 		/*
 		 * Backward compatibility for between v5.12 - v5.19
@@ -2044,6 +2052,6 @@ static struct platform_driver rcar_dmac_driver = {
 
 module_platform_driver(rcar_dmac_driver);
 
-MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver");
+MODULE_DESCRIPTION("R-Car DMA Controller Driver");
 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 MODULE_LICENSE("GPL v2");
-- 
2.47.3

Re: [PATCH 1/4] dmaengine: sh: rcar-dmac: fix style in struct initialization

[Frank Li]

On Tue, Aug 25, 2026 at 04:15:43PM +0200, Wolfram Sang wrote:
> A new member will be added to the struct. Before that, adhere to coding
> style by using a single space when assigning values.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/dma/sh/rcar-dmac.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
> index 44eab2d21d54..cf07c17847d0 100644
> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -1998,13 +1998,13 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
>  }
>
>  static const struct rcar_dmac_of_data rcar_dmac_data = {
> -	.chan_offset_base	= 0x8000,
> -	.chan_offset_stride	= 0x80,
> +	.chan_offset_base = 0x8000,
> +	.chan_offset_stride = 0x80,
>  };
>
>  static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
> -	.chan_offset_base	= 0x0,
> -	.chan_offset_stride	= 0x1000,
> +	.chan_offset_base = 0x0,
> +	.chan_offset_stride = 0x1000,
>  };
>
>  static const struct of_device_id rcar_dmac_of_ids[] = {
> --
> 2.47.3
>

Re: [PATCH 2/4] dmaengine: sh: rcar-dmac: SMMU doesn't need IPMMU workaround

[Frank Li]

On Tue, Aug 25, 2026 at 04:15:44PM +0200, Wolfram Sang wrote:
> R-Car Gen5 doesn't use an IPMMU anymore, but a SMMU. So, the workaround
> for the IPMMU becomes optional. Add a flag to distinguish. No functional
> change.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  drivers/dma/sh/rcar-dmac.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
> index cf07c17847d0..9c5210257097 100644
> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -219,10 +219,12 @@ struct rcar_dmac {
>   * struct rcar_dmac_of_data - This driver's OF data
>   * @chan_offset_base: DMAC channels base offset
>   * @chan_offset_stride: DMAC channels offset stride
> + * @has_ipmmu: flag telling if DMAC is connected to an IPMMU
>   */
>  struct rcar_dmac_of_data {
>  	u32 chan_offset_base;
>  	u32 chan_offset_stride;
> +	unsigned int has_ipmmu:1;

Nit: most similar case use bool

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  };
>
>  /* -----------------------------------------------------------------------------
> @@ -1877,8 +1879,9 @@ static int rcar_dmac_probe(struct platform_device *pdev)
>  	 * can't use it with the IPMMU. As the IOMMU API operates at the device
>  	 * level we can't disable it selectively, so ignore channel 0 for now if
>  	 * the device is part of an IOMMU group.
> +	 * Not applicable if system uses something else than IPMMU like SMMU.
>  	 */
> -	if (device_iommu_mapped(&pdev->dev))
> +	if (data->has_ipmmu && device_iommu_mapped(&pdev->dev))
>  		dmac->channels_mask &= ~BIT(0);
>
>  	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
> @@ -2000,11 +2003,13 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
>  static const struct rcar_dmac_of_data rcar_dmac_data = {
>  	.chan_offset_base = 0x8000,
>  	.chan_offset_stride = 0x80,
> +	.has_ipmmu = 1,
>  };
>
>  static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
>  	.chan_offset_base = 0x0,
>  	.chan_offset_stride = 0x1000,
> +	.has_ipmmu = 1,
>  };
>
>  static const struct of_device_id rcar_dmac_of_ids[] = {
> --
> 2.47.3
>

Re: [PATCH 4/4] dmaengine: sh: rcar-dmac: Add support for R-Car Gen5 SoCs

[Frank Li]

On Tue, Aug 25, 2026 at 04:15:46PM +0200, Wolfram Sang wrote:
> Gen5 is very similar to Gen4. Of interest here is that it has a SMMU
> instead of an IPMMU, so we don't need to set the flag for a workaround.

Generally, needn't "we",  simple said

needn't to set ...

Frank

> Make the module description more generic while here.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  drivers/dma/sh/rcar-dmac.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
> index 9c5210257097..06f691f5f3fb 100644
> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -2012,6 +2012,11 @@ static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
>  	.has_ipmmu = 1,
>  };
>
> +static const struct rcar_dmac_of_data rcar_gen5_dmac_data = {
> +	.chan_offset_base = 0x0,
> +	.chan_offset_stride = 0x1000,
> +};
> +
>  static const struct of_device_id rcar_dmac_of_ids[] = {
>  	{
>  		.compatible = "renesas,rcar-dmac",
> @@ -2019,6 +2024,9 @@ static const struct of_device_id rcar_dmac_of_ids[] = {
>  	}, {
>  		.compatible = "renesas,rcar-gen4-dmac",
>  		.data = &rcar_gen4_dmac_data,
> +	}, {
> +		.compatible = "renesas,rcar-gen5-dmac",
> +		.data = &rcar_gen5_dmac_data,
>  	}, {
>  		/*
>  		 * Backward compatibility for between v5.12 - v5.19
> @@ -2044,6 +2052,6 @@ static struct platform_driver rcar_dmac_driver = {
>
>  module_platform_driver(rcar_dmac_driver);
>
> -MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver");
> +MODULE_DESCRIPTION("R-Car DMA Controller Driver");
>  MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
>  MODULE_LICENSE("GPL v2");
> --
> 2.47.3
>

Re: [PATCH 4/4] dmaengine: sh: rcar-dmac: Add support for R-Car Gen5 SoCs

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 416 bytes --]

On Tue, Aug 25, 2026 at 10:40:31AM -0500, Frank Li wrote:
> On Tue, Aug 25, 2026 at 04:15:46PM +0200, Wolfram Sang wrote:
> > Gen5 is very similar to Gen4. Of interest here is that it has a SMMU
> > instead of an IPMMU, so we don't need to set the flag for a workaround.
> 
> Generally, needn't "we",  simple said
> 
> needn't to set ...

Can do, will wait a bit more for more comments before resending.


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Re: [PATCH 3/4] dt-bindings: renesas,rcar-dmac: Add support for R-Car X5H SoC

[Krzysztof Kozlowski]

On Tue, Aug 25, 2026 at 04:15:45PM +0200, Wolfram Sang wrote:
> Also add the familiy compatible because X5H is the first R-Car Gen5 SoC.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  .../devicetree/bindings/dma/renesas,rcar-dmac.yaml          | 6 ++++++
>  1 file changed, 6 insertions(+)

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof