[PATCH v2 0/4] Add Aspeed AST2700 uhci support

[PATCH v2 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.

v2:
- usb-uhci.yaml
 - add required resets for aspeed,ast2700-uhci
- uhci-platform.c
 - change the err_clk before err_reset.

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     | 13 ++++++++
 drivers/usb/host/uhci-hcd.h                   |  1 +
 drivers/usb/host/uhci-platform.c              | 32 +++++++++++++++----
 3 files changed, 40 insertions(+), 6 deletions(-)

-- 
2.34.1

[PATCH v2 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

[PATCH v2 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 | 17 +++++++++++++++--
 2 files changed, 16 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..1c1715bddc27 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)
 {
@@ -132,17 +133,29 @@ 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_reset:
+	if (!IS_ERR_OR_NULL(uhci->rsts))
+		reset_control_assert(uhci->rsts);
 err_clk:
 	clk_disable_unprepare(uhci->clk);
 err_rmr:
-- 
2.34.1

[PATCH v2 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 | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/usb-uhci.yaml b/Documentation/devicetree/bindings/usb/usb-uhci.yaml
index b1f2b9bd7921..7b774d0b2742 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:
@@ -53,6 +54,15 @@ allOf:
       required:
         - clocks
 
+ - if:
+      properties:
+        compatible:
+          contains:
+            const: aspeed,ast2700-uhci
+    then:
+      required:
+        - resets
+
 unevaluatedProperties: false
 
 examples:
-- 
2.34.1

[PATCH v2 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 1c1715bddc27..84867f75dfcd 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");
@@ -188,9 +191,13 @@ 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

Re: [PATCH v2 2/4] usb: uhci: Add reset control support

[Alan Stern]

On Wed, Sep 17, 2025 at 10:19:24AM +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 | 17 +++++++++++++++--
>  2 files changed, 16 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 */

This new field is used only in uhci_hcd_platform_probe().  Therefore it 
does not need to be stored in the uhci_hcd structure; it can simply be a 
local variable.

Alan Stern

>  
>  	/* 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..1c1715bddc27 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)
>  {
> @@ -132,17 +133,29 @@ 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_reset:
> +	if (!IS_ERR_OR_NULL(uhci->rsts))
> +		reset_control_assert(uhci->rsts);
>  err_clk:
>  	clk_disable_unprepare(uhci->clk);
>  err_rmr:
> -- 
> 2.34.1
> 

Re: [PATCH v2 1/4] dt-bindings: usb: uhci: Add reset property

[Conor Dooley]

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

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Re: [PATCH v2 3/4] dt-bindings: usb: uhci: Add Aspeed AST2700 compatible

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 52 bytes --]

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

[-- Attachment #2: signature.asc --]
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RE: [PATCH v2 2/4] usb: uhci: Add reset control support

[Ryan Chen]

> Subject: Re: [PATCH v2 2/4] usb: uhci: Add reset control support
> 
> On Wed, Sep 17, 2025 at 10:19:24AM +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 | 17 +++++++++++++++--
> >  2 files changed, 16 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 */
> 
> This new field is used only in uhci_hcd_platform_probe().  Therefore it does
> not need to be stored in the uhci_hcd structure; it can simply be a local
> variable.
> 
> Alan Stern

Sorry, I think I miss add reset_control_assert in uhci_hcd_platform_remove function.
So, It is needed in uhci_hcd structure, I will submit in next.
Thanks your review.
> 
> >
> >  	/* 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..1c1715bddc27 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)  { @@ -132,17
> > +133,29 @@ 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_reset:
> > +	if (!IS_ERR_OR_NULL(uhci->rsts))
> > +		reset_control_assert(uhci->rsts);
> >  err_clk:
> >  	clk_disable_unprepare(uhci->clk);
> >  err_rmr:
> > --
> > 2.34.1
> >