[PATCH 0/4] Add Aspeed AST2700 uhci support

[PATCH 0/4] Add Aspeed AST2700 uhci support

[Ryan Chen]

This patch series adds support for the UHCI controller found on the
Aspeed AST2700 SoC.

Compared to earlier SoCs (AST2400/2500/2600), AST2700 UHCI:
 - requires a reset line to be deasserted before use
 - supports 64-bit DMA addressing

This series updates the bindings and platform driver accordingly.

Ryan Chen (4):
  dt-bindings: usb: uhci: Add reset property
  usb: uhci: Add reset control support
  dt-bindings: usb: uhci: Add Aspeed AST2700 compatible
  usb: uhci: Add Aspeed AST2700 support

 .../devicetree/bindings/usb/usb-uhci.yaml     |  4 +++
 drivers/usb/host/uhci-hcd.h                   |  1 +
 drivers/usb/host/uhci-platform.c              | 34 +++++++++++++++----
 3 files changed, 33 insertions(+), 6 deletions(-)

-- 
2.34.1

[PATCH 1/4] dt-bindings: usb: uhci: Add reset property

[Ryan Chen]

The UHCI controller on Aspeed SoCs (including AST2700) requires
its reset line to be deasserted before the controller can be used.
Add an optional "resets" property to the UHCI device tree bindings
to describe the phandle to the reset controller.

This property is optional for platforms which do not require
explicit reset handling.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 Documentation/devicetree/bindings/usb/usb-uhci.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/usb-uhci.yaml b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
index d8336f72dc1f..b1f2b9bd7921 100644
--- a/Documentation/devicetree/bindings/usb/usb-uhci.yaml
+++ b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
@@ -28,6 +28,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  resets:
+    maxItems: 1
+
   '#ports':
     $ref: /schemas/types.yaml#/definitions/uint32
 
-- 
2.34.1

Re: [PATCH 1/4] dt-bindings: usb: uhci: Add reset property

[Conor Dooley]

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On Mon, Sep 15, 2025 at 03:39:23PM +0800, Ryan Chen wrote:
> The UHCI controller on Aspeed SoCs (including AST2700) requires
> its reset line to be deasserted before the controller can be used.
> Add an optional "resets" property to the UHCI device tree bindings
> to describe the phandle to the reset controller.

Looks like the property is not optional at all for your aspeed devices,
and you should require it for those compatibles.

> 
> This property is optional for platforms which do not require
> explicit reset handling.
> 
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
>  Documentation/devicetree/bindings/usb/usb-uhci.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-uhci.yaml b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> index d8336f72dc1f..b1f2b9bd7921 100644
> --- a/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> +++ b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> @@ -28,6 +28,9 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  resets:
> +    maxItems: 1
> +
>    '#ports':
>      $ref: /schemas/types.yaml#/definitions/uint32
>  
> -- 
> 2.34.1
> 

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RE: [PATCH 1/4] dt-bindings: usb: uhci: Add reset property

[Ryan Chen]

> Subject: Re: [PATCH 1/4] dt-bindings: usb: uhci: Add reset property
> 
> On Mon, Sep 15, 2025 at 03:39:23PM +0800, Ryan Chen wrote:
> > The UHCI controller on Aspeed SoCs (including AST2700) requires its
> > reset line to be deasserted before the controller can be used.
> > Add an optional "resets" property to the UHCI device tree bindings to
> > describe the phandle to the reset controller.
> 
> Looks like the property is not optional at all for your aspeed devices, and you
> should require it for those compatibles.
> 
> >
> > This property is optional for platforms which do not require explicit
> > reset handling.

Thanks, resets is required for ast2700-uhci.
I will add in following.

- if:
      properties:
        compatible:
          contains:
            const: aspeed,ast2700-uhci
    then:
      required:
        - resets

> >
> > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > ---
> >  Documentation/devicetree/bindings/usb/usb-uhci.yaml | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> > b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> > index d8336f72dc1f..b1f2b9bd7921 100644
> > --- a/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> > +++ b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
> > @@ -28,6 +28,9 @@ properties:
> >    interrupts:
> >      maxItems: 1
> >
> > +  resets:
> > +    maxItems: 1
> > +
> >    '#ports':
> >      $ref: /schemas/types.yaml#/definitions/uint32
> >
> > --
> > 2.34.1
> >

[PATCH 2/4] usb: uhci: Add reset control support

[Ryan Chen]

Some SoCs, such as the Aspeed AST2700, require the UHCI controller
to be taken out of reset before it can operate. Add optional reset
control support to the UHCI platform driver.

The driver now acquires an optional reset line from device tree,
deasserts it during probe, and asserts it again in the error path
and shutdown.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 drivers/usb/host/uhci-hcd.h      |  1 +
 drivers/usb/host/uhci-platform.c | 19 +++++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 13ee2a6144b2..4326d1f3ca76 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -445,6 +445,7 @@ struct uhci_hcd {
 	short load[MAX_PHASE];			/* Periodic allocations */
 
 	struct clk *clk;			/* (optional) clock source */
+	struct reset_control *rsts;		/* (optional) clock reset */
 
 	/* Reset host controller */
 	void	(*reset_hc) (struct uhci_hcd *uhci);
diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
index 62318291f566..010c458e7d8f 100644
--- a/drivers/usb/host/uhci-platform.c
+++ b/drivers/usb/host/uhci-platform.c
@@ -11,6 +11,7 @@
 #include <linux/of.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 
 static int uhci_platform_init(struct usb_hcd *hcd)
 {
@@ -132,19 +133,33 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
 		goto err_rmr;
 	}
 
+	uhci->rsts = devm_reset_control_array_get_optional_shared(&pdev->dev);
+	if (IS_ERR(uhci->rsts)) {
+		ret = PTR_ERR(uhci->rsts);
+		goto err_clk;
+	}
+	ret = reset_control_deassert(uhci->rsts);
+	if (ret)
+		goto err_clk;
+
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
-		goto err_clk;
+		goto err_reset;
 
 	ret = usb_add_hcd(hcd, ret, IRQF_SHARED);
 	if (ret)
-		goto err_clk;
+		goto err_reset;
 
 	device_wakeup_enable(hcd->self.controller);
 	return 0;
 
 err_clk:
 	clk_disable_unprepare(uhci->clk);
+
+err_reset:
+	if (!IS_ERR_OR_NULL(uhci->rsts))
+		reset_control_assert(uhci->rsts);
+
 err_rmr:
 	usb_put_hcd(hcd);
 
-- 
2.34.1

Re: [PATCH 2/4] usb: uhci: Add reset control support

[Alan Stern]

On Mon, Sep 15, 2025 at 03:39:24PM +0800, Ryan Chen wrote:
> Some SoCs, such as the Aspeed AST2700, require the UHCI controller
> to be taken out of reset before it can operate. Add optional reset
> control support to the UHCI platform driver.
> 
> The driver now acquires an optional reset line from device tree,
> deasserts it during probe, and asserts it again in the error path
> and shutdown.
> 
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
>  drivers/usb/host/uhci-hcd.h      |  1 +
>  drivers/usb/host/uhci-platform.c | 19 +++++++++++++++++--
>  2 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> index 13ee2a6144b2..4326d1f3ca76 100644
> --- a/drivers/usb/host/uhci-hcd.h
> +++ b/drivers/usb/host/uhci-hcd.h
> @@ -445,6 +445,7 @@ struct uhci_hcd {
>  	short load[MAX_PHASE];			/* Periodic allocations */
>  
>  	struct clk *clk;			/* (optional) clock source */
> +	struct reset_control *rsts;		/* (optional) clock reset */
>  
>  	/* Reset host controller */
>  	void	(*reset_hc) (struct uhci_hcd *uhci);
> diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
> index 62318291f566..010c458e7d8f 100644
> --- a/drivers/usb/host/uhci-platform.c
> +++ b/drivers/usb/host/uhci-platform.c
> @@ -11,6 +11,7 @@
>  #include <linux/of.h>
>  #include <linux/device.h>
>  #include <linux/platform_device.h>
> +#include <linux/reset.h>
>  
>  static int uhci_platform_init(struct usb_hcd *hcd)
>  {
> @@ -132,19 +133,33 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
>  		goto err_rmr;
>  	}
>  
> +	uhci->rsts = devm_reset_control_array_get_optional_shared(&pdev->dev);
> +	if (IS_ERR(uhci->rsts)) {
> +		ret = PTR_ERR(uhci->rsts);
> +		goto err_clk;
> +	}
> +	ret = reset_control_deassert(uhci->rsts);
> +	if (ret)
> +		goto err_clk;
> +
>  	ret = platform_get_irq(pdev, 0);
>  	if (ret < 0)
> -		goto err_clk;
> +		goto err_reset;
>  
>  	ret = usb_add_hcd(hcd, ret, IRQF_SHARED);
>  	if (ret)
> -		goto err_clk;
> +		goto err_reset;
>  
>  	device_wakeup_enable(hcd->self.controller);
>  	return 0;
>  
>  err_clk:
>  	clk_disable_unprepare(uhci->clk);
> +
> +err_reset:
> +	if (!IS_ERR_OR_NULL(uhci->rsts))
> +		reset_control_assert(uhci->rsts);

This error handler was added in the wrong place.  It should come before 
err_clk, so that if an error occurs in platform_get_irq(), the clock 
will be unprepared and disabled.

Alan Stern

> +
>  err_rmr:
>  	usb_put_hcd(hcd);
>  
> -- 
> 2.34.1

RE: [PATCH 2/4] usb: uhci: Add reset control support

[Ryan Chen]

> Subject: Re: [PATCH 2/4] usb: uhci: Add reset control support
> 
> On Mon, Sep 15, 2025 at 03:39:24PM +0800, Ryan Chen wrote:
> > Some SoCs, such as the Aspeed AST2700, require the UHCI controller to
> > be taken out of reset before it can operate. Add optional reset
> > control support to the UHCI platform driver.
> >
> > The driver now acquires an optional reset line from device tree,
> > deasserts it during probe, and asserts it again in the error path and
> > shutdown.
> >
> > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > ---
> >  drivers/usb/host/uhci-hcd.h      |  1 +
> >  drivers/usb/host/uhci-platform.c | 19 +++++++++++++++++--
> >  2 files changed, 18 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > index 13ee2a6144b2..4326d1f3ca76 100644
> > --- a/drivers/usb/host/uhci-hcd.h
> > +++ b/drivers/usb/host/uhci-hcd.h
> > @@ -445,6 +445,7 @@ struct uhci_hcd {
> >  	short load[MAX_PHASE];			/* Periodic allocations */
> >
> >  	struct clk *clk;			/* (optional) clock source */
> > +	struct reset_control *rsts;		/* (optional) clock reset */
> >
> >  	/* Reset host controller */
> >  	void	(*reset_hc) (struct uhci_hcd *uhci);
> > diff --git a/drivers/usb/host/uhci-platform.c
> > b/drivers/usb/host/uhci-platform.c
> > index 62318291f566..010c458e7d8f 100644
> > --- a/drivers/usb/host/uhci-platform.c
> > +++ b/drivers/usb/host/uhci-platform.c
> > @@ -11,6 +11,7 @@
> >  #include <linux/of.h>
> >  #include <linux/device.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/reset.h>
> >
> >  static int uhci_platform_init(struct usb_hcd *hcd)  { @@ -132,19
> > +133,33 @@ static int uhci_hcd_platform_probe(struct platform_device
> *pdev)
> >  		goto err_rmr;
> >  	}
> >
> > +	uhci->rsts = devm_reset_control_array_get_optional_shared(&pdev->dev);
> > +	if (IS_ERR(uhci->rsts)) {
> > +		ret = PTR_ERR(uhci->rsts);
> > +		goto err_clk;
> > +	}
> > +	ret = reset_control_deassert(uhci->rsts);
> > +	if (ret)
> > +		goto err_clk;
> > +
> >  	ret = platform_get_irq(pdev, 0);
> >  	if (ret < 0)
> > -		goto err_clk;
> > +		goto err_reset;
> >
> >  	ret = usb_add_hcd(hcd, ret, IRQF_SHARED);
> >  	if (ret)
> > -		goto err_clk;
> > +		goto err_reset;
> >
> >  	device_wakeup_enable(hcd->self.controller);
> >  	return 0;
> >
> >  err_clk:
> >  	clk_disable_unprepare(uhci->clk);
> > +
> > +err_reset:
> > +	if (!IS_ERR_OR_NULL(uhci->rsts))
> > +		reset_control_assert(uhci->rsts);
> 
> This error handler was added in the wrong place.  It should come before
> err_clk, so that if an error occurs in platform_get_irq(), the clock will be
> unprepared and disabled.

Thanks, will update in next version.

> 
> Alan Stern
> 
> > +
> >  err_rmr:
> >  	usb_put_hcd(hcd);
> >
> > --
> > 2.34.1

[PATCH 3/4] dt-bindings: usb: uhci: Add Aspeed AST2700 compatible

[Ryan Chen]

Add the compatible string for Aspeed AST2700 SoC.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 Documentation/devicetree/bindings/usb/usb-uhci.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/usb/usb-uhci.yaml b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
index b1f2b9bd7921..6861c1d3c5eb 100644
--- a/Documentation/devicetree/bindings/usb/usb-uhci.yaml
+++ b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
@@ -20,6 +20,7 @@ properties:
               - aspeed,ast2400-uhci
               - aspeed,ast2500-uhci
               - aspeed,ast2600-uhci
+              - aspeed,ast2700-uhci
           - const: generic-uhci
 
   reg:
-- 
2.34.1

Re: [PATCH 3/4] dt-bindings: usb: uhci: Add Aspeed AST2700 compatible

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>

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RE: [PATCH 3/4] dt-bindings: usb: uhci: Add Aspeed AST2700 compatible

[Ryan Chen]

> Subject: Re: [PATCH 3/4] dt-bindings: usb: uhci: Add Aspeed AST2700
> compatible
Hello Conor,
	I will add resets required in this patch at next send patch, is this ok for you?
https://lore.kernel.org/all/OS8PR06MB75419B97CDB5EA24560FB9ECF214A@OS8PR06MB7541.apcprd06.prod.outlook.com/

> 
> Acked-by: Conor Dooley <conor.dooley@microchip.com>

[PATCH 4/4] usb: uhci: Add Aspeed AST2700 support

[Ryan Chen]

Unlike earlier Aspeed SoCs (AST2400/2500/2600) which are limited to
32-bit DMA addressing, the UHCI controller in AST2700 supports 64-bit
DMA. Update the platform UHCI driver to select the appropriate DMA
mask based on the device tree compatible string.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 drivers/usb/host/uhci-platform.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
index 010c458e7d8f..24628b0ce99b 100644
--- a/drivers/usb/host/uhci-platform.c
+++ b/drivers/usb/host/uhci-platform.c
@@ -71,6 +71,7 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
 	struct usb_hcd *hcd;
 	struct uhci_hcd	*uhci;
 	struct resource *res;
+	u64 *dma_mask_ptr;
 	int ret;
 
 	if (usb_disabled())
@@ -81,7 +82,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
 	 * Since shared usb code relies on it, set it here for now.
 	 * Once we have dma capability bindings this can go away.
 	 */
-	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+	dma_mask_ptr = (u64 *)of_device_get_match_data(&pdev->dev);
+	ret = dma_coerce_mask_and_coherent(&pdev->dev, *dma_mask_ptr);
 	if (ret)
 		return ret;
 
@@ -114,7 +116,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
 		}
 		if (of_device_is_compatible(np, "aspeed,ast2400-uhci") ||
 		    of_device_is_compatible(np, "aspeed,ast2500-uhci") ||
-		    of_device_is_compatible(np, "aspeed,ast2600-uhci")) {
+		    of_device_is_compatible(np, "aspeed,ast2600-uhci") ||
+		    of_device_is_compatible(np, "aspeed,ast2700-uhci")) {
 			uhci->is_aspeed = 1;
 			dev_info(&pdev->dev,
 				 "Enabled Aspeed implementation workarounds\n");
@@ -190,9 +193,13 @@ static void uhci_hcd_platform_shutdown(struct platform_device *op)
 	uhci_hc_died(hcd_to_uhci(hcd));
 }
 
+static const u64 dma_mask_32 =	DMA_BIT_MASK(32);
+static const u64 dma_mask_64 =	DMA_BIT_MASK(64);
+
 static const struct of_device_id platform_uhci_ids[] = {
-	{ .compatible = "generic-uhci", },
-	{ .compatible = "platform-uhci", },
+	{ .compatible = "generic-uhci", .data = &dma_mask_32},
+	{ .compatible = "platform-uhci", .data = &dma_mask_32},
+	{ .compatible = "aspeed,ast2700-uhci", .data = &dma_mask_64},
 	{}
 };
 MODULE_DEVICE_TABLE(of, platform_uhci_ids);
-- 
2.34.1