[PATCH v7 0/2] Add SpacemiT K1 USB3.0 host controller support

[PATCH v7 0/2] Add SpacemiT K1 USB3.0 host controller support

[Ze Huang]

The USB 3.0 controller found in the SpacemiT K1 SoC[1] supports both USB3.0
Host and USB2.0 Dual-Role Device (DRD). 

This controller is compatible with DesignWare Core USB 3 (DWC3) driver.
However, constraints in the `snps,dwc3` bindings limit the ability to describe
hardware-specific features in a clean and maintainable way. While
`dwc3-of-simple` still serves as a glue layer for many platforms, it requires a
split device tree node structure, which is less desirable in newer platforms.

To promote a transition toward a flattened `dwc` node structure, this series
introduces `dwc3-generic-plat`, building upon prior efforts that exposed the
DWC3 core driver [2].

The device tree support for SpacemiT K1 will be submitted separately when the
associated PHY driver is ready.

This series is based on 6.16-rc1 and has been tested on BananaPi development
boards.

Link: https://developer.spacemit.com/documentation?token=AjHDwrW78igAAEkiHracBI9HnTb [1]
Link: https://lore.kernel.org/all/20250414-dwc3-refactor-v7-3-f015b358722d@oss.qualcomm.com [2]

Signed-off-by: Ze Huang <huang.ze@linux.dev>
---
Changes in v7:
- dt-bindings:
  - add reset-names and reset-delay properties
  - add pcie0 entry in resets for combphy init
- dwc3 generic plat driver:
  - drop clock cleanup and handle with devm_clk_bulk_get_all_enabled()
  - move devm reset action after successful de-assert
- Link to v6: https://lore.kernel.org/r/20250712-dwc3_generic-v6-0-cc87737cc936@linux.dev

Changes in v6:
- replace SET_RUNTIME_PM_OPS/SET_SYSTEM_SLEEP_PM_OPS with RUNTIME_PM_OPS/SYSTEM_SLEEP_PM_OPS
- Link to v5: https://lore.kernel.org/r/20250705-dwc3_generic-v5-0-9dbc53ea53d2@linux.dev

Changes in v5:
- drop DTS patch (will submit when PHY driver is ready)
- drop interconnects and update resets property in dt-bindings
- remove unnecessary __maybe_unused attribute and PM guards
- switch to devres APIs for reset and clock management
- Link to v4: https://lore.kernel.org/all/20250526-b4-k1-dwc3-v3-v4-0-63e4e525e5cb@whut.edu.cn/

Changes in v4:
- dt-bindings spacemit,k1-dwc:
  - reorder properties
  - add properties of phys & phy-names
  - add usb hub nodes in example dt
- add support for spacemit,k1-mbus
- dwc3 generic plat driver:
  - rename dwc3-common.c to dwc3-generic-plat.c
  - use SYSTEM_SLEEP_PM_OPS macros and drop PM guards
- dts:
  - reorder dts properties of usb dwc3 node
  - move "dr_mode" of dwc3 from dtsi to dts
- Link to v3: https://lore.kernel.org/r/20250518-b4-k1-dwc3-v3-v3-0-7609c8baa2a6@whut.edu.cn

Changes in v3:
- introduce dwc3-common for generic dwc3 hardware
- fix warnings in usb host dt-bindings
- fix errors in dts
- Link to v2: https://lore.kernel.org/r/20250428-b4-k1-dwc3-v2-v1-0-7cb061abd619@whut.edu.cn

Changes in v2:
- dt-bindings:
  - add missing 'maxItems'
  - remove 'status' property in exmaple
  - fold dwc3 node into parent
- drop dwc3 glue driver and use snps,dwc3 driver directly
- rename dts nodes and reorder properties to fit coding style
- Link to v1: https://lore.kernel.org/all/20250407-b4-k1-usb3-v3-2-v1-0-bf0bcc41c9ba@whut.edu.cn

---
Ze Huang (2):
      dt-bindings: usb: dwc3: add support for SpacemiT K1
      usb: dwc3: add generic driver to support flattened

 .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++
 drivers/usb/dwc3/Kconfig                           |  11 ++
 drivers/usb/dwc3/Makefile                          |   1 +
 drivers/usb/dwc3/dwc3-generic-plat.c               | 167 +++++++++++++++++++++
 4 files changed, 303 insertions(+)
---
base-commit: d9946fe286439c2aeaa7953b8c316efe5b83d515
change-id: 20250705-dwc3_generic-8d02859722c3

Best regards,
-- 
Ze Huang <huang.ze@linux.dev>

[PATCH v7 1/2] dt-bindings: usb: dwc3: add support for SpacemiT K1

[Ze Huang]

Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
in the SpacemiT K1 SoC. The controller is based on the Synopsys
DesignWare Core USB 3 (DWC3) IP, supporting USB3.0 host mode and USB 2.0
DRD mode.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Ze Huang <huang.ze@linux.dev>
---
 .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++++++++
 1 file changed, 124 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..7007e2bd42016ae0e50c4007e75d26bada34d983
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/spacemit,k1-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 SuperSpeed DWC3 USB SoC Controller
+
+maintainers:
+  - Ze Huang <huang.ze@linux.dev>
+
+description: |
+  The SpacemiT K1 embeds a DWC3 USB IP Core which supports Host functions
+  for USB 3.0 and DRD for USB 2.0.
+
+  Key features:
+  - USB3.0 SuperSpeed and USB2.0 High/Full/Low-Speed support
+  - Supports low-power modes (USB2.0 suspend, USB3.0 U1/U2/U3)
+  - Internal DMA controller and flexible endpoint FIFO sizing
+
+  Communication Interface:
+  - Use of PIPE3 (125MHz) interface for USB3.0 PHY
+  - Use of UTMI+ (30/60MHz) interface for USB2.0 PHY
+
+allOf:
+  - $ref: snps,dwc3-common.yaml#
+
+properties:
+  compatible:
+    const: spacemit,k1-dwc3
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: usbdrd30
+
+  interrupts:
+    maxItems: 1
+
+  phys:
+    items:
+      - description: phandle to USB2/HS PHY
+      - description: phandle to USB3/SS PHY
+
+  phy-names:
+    items:
+      - const: usb2-phy
+      - const: usb3-phy
+
+  resets:
+    items:
+      - description: USB3.0 AHB reset
+      - description: USB3.0 VCC reset
+      - description: USB3.0 PHY reset
+      - description: PCIE0 global reset (for combo phy)
+
+  reset-names:
+    items:
+      - const: ahb
+      - const: vcc
+      - const: phy
+      - const: pcie0
+
+  reset-delay:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 2
+    description: delay after reset sequence [us]
+
+  vbus-supply:
+    description: A phandle to the regulator supplying the VBUS voltage.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+  - phys
+  - phy-names
+  - resets
+  - reset-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    usb@c0a00000 {
+        compatible = "spacemit,k1-dwc3";
+        reg = <0xc0a00000 0x10000>;
+        clocks = <&syscon_apmu 16>;
+        clock-names = "usbdrd30";
+        interrupts = <125>;
+        phys = <&usb2phy>, <&usb3phy>;
+        phy-names = "usb2-phy", "usb3-phy";
+        resets = <&syscon_apmu 8>,
+                 <&syscon_apmu 9>,
+                 <&syscon_apmu 10>,
+                 <&syscon_apmu 26>;
+        reset-names = "ahb", "vcc", "phy", "pcie0";
+        reset-delay = <2>;
+        vbus-supply = <&usb3_vbus>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        hub_2_0: hub@1 {
+            compatible = "usb2109,2817";
+            reg = <1>;
+            vdd-supply = <&usb3_vhub>;
+            peer-hub = <&hub_3_0>;
+            reset-gpios = <&gpio 3 28 1>;
+        };
+
+        hub_3_0: hub@2 {
+            compatible = "usb2109,817";
+            reg = <2>;
+            vdd-supply = <&usb3_vhub>;
+            peer-hub = <&hub_2_0>;
+            reset-gpios = <&gpio 3 28 1>;
+        };
+    };

-- 
2.50.1

[PATCH v7 2/2] usb: dwc3: add generic driver to support flattened

[Ze Huang]

To support flattened dwc3 dt model and drop the glue layer, introduce the
`dwc3-generic` driver. This enables direct binding of the DWC3 core driver
and offers an alternative to the existing glue driver `dwc3-of-simple`.

Signed-off-by: Ze Huang <huang.ze@linux.dev>
---
 drivers/usb/dwc3/Kconfig             |  11 +++
 drivers/usb/dwc3/Makefile            |   1 +
 drivers/usb/dwc3/dwc3-generic-plat.c | 167 +++++++++++++++++++++++++++++++++++
 3 files changed, 179 insertions(+)

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 310d182e10b50b253d7e5a51674806e6ec442a2a..4925d15084f816d3ff92059b476ebcc799b56b51 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -189,4 +189,15 @@ config USB_DWC3_RTK
 	  or dual-role mode.
 	  Say 'Y' or 'M' if you have such device.
 
+config USB_DWC3_GENERIC_PLAT
+	tristate "DWC3 Generic Platform Driver"
+	depends on OF && COMMON_CLK
+	default USB_DWC3
+	help
+	  Support USB3 functionality in simple SoC integrations.
+	  Currently supports SpacemiT DWC USB3. Platforms using
+	  dwc3-of-simple can easily switch to dwc3-generic by flattening
+	  the dwc3 child node in the device tree.
+	  Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
+
 endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 830e6c9e5fe073c1f662ce34b6a4a2da34c407a2..96469e48ff9d189cc8d0b65e65424eae2158bcfe 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -57,3 +57,4 @@ obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
 obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
 obj-$(CONFIG_USB_DWC3_OCTEON)		+= dwc3-octeon.o
 obj-$(CONFIG_USB_DWC3_RTK)		+= dwc3-rtk.o
+obj-$(CONFIG_USB_DWC3_GENERIC_PLAT)	+= dwc3-generic-plat.o
diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
new file mode 100644
index 0000000000000000000000000000000000000000..abb144867bf5f678223483c948521ceb44d05190
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-generic-plat.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dwc3-generic-plat.c - DesignWare USB3 generic platform driver
+ *
+ * Copyright (C) 2025 Ze Huang <huang.ze@linux.dev>
+ *
+ * Inspired by dwc3-qcom.c and dwc3-of-simple.c
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include "glue.h"
+
+struct dwc3_generic {
+	struct device		*dev;
+	struct dwc3		dwc;
+	struct clk_bulk_data	*clks;
+	int			num_clocks;
+	struct reset_control	*resets;
+};
+
+static void dwc3_generic_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int dwc3_generic_probe(struct platform_device *pdev)
+{
+	struct dwc3_probe_data probe_data = {};
+	struct device *dev = &pdev->dev;
+	struct dwc3_generic *dwc3;
+	struct resource *res;
+	int ret;
+
+	dwc3 = devm_kzalloc(dev, sizeof(*dwc3), GFP_KERNEL);
+	if (!dwc3)
+		return -ENOMEM;
+
+	dwc3->dev = dev;
+
+	platform_set_drvdata(pdev, dwc3);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource\n");
+		return -ENODEV;
+	}
+
+	dwc3->resets = devm_reset_control_array_get_optional_exclusive(dev);
+	if (IS_ERR(dwc3->resets))
+		return dev_err_probe(dev, PTR_ERR(dwc3->resets), "failed to get resets\n");
+
+	ret = reset_control_assert(dwc3->resets);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to assert resets\n");
+
+	/* Not strict timing, just for safety */
+	udelay(2);
+
+	ret = reset_control_deassert(dwc3->resets);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to deassert resets\n");
+
+	ret = devm_add_action_or_reset(dev, dwc3_generic_reset_control_assert, dwc3->resets);
+	if (ret)
+		return ret;
+
+	ret = devm_clk_bulk_get_all_enabled(dwc3->dev, &dwc3->clks);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to get clocks\n");
+
+	dwc3->num_clocks = ret;
+	dwc3->dwc.dev = dev;
+	probe_data.dwc = &dwc3->dwc;
+	probe_data.res = res;
+	probe_data.ignore_clocks_and_resets = true;
+	ret = dwc3_core_probe(&probe_data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
+
+	return 0;
+}
+
+static void dwc3_generic_remove(struct platform_device *pdev)
+{
+	struct dwc3_generic *dwc3 = platform_get_drvdata(pdev);
+
+	dwc3_core_remove(&dwc3->dwc);
+}
+
+static int dwc3_generic_suspend(struct device *dev)
+{
+	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
+	int ret;
+
+	ret = dwc3_pm_suspend(&dwc3->dwc);
+	if (ret)
+		return ret;
+
+	clk_bulk_disable_unprepare(dwc3->num_clocks, dwc3->clks);
+
+	return 0;
+}
+
+static int dwc3_generic_resume(struct device *dev)
+{
+	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_bulk_prepare_enable(dwc3->num_clocks, dwc3->clks);
+	if (ret)
+		return ret;
+
+	ret = dwc3_pm_resume(&dwc3->dwc);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int dwc3_generic_runtime_suspend(struct device *dev)
+{
+	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
+
+	return dwc3_runtime_suspend(&dwc3->dwc);
+}
+
+static int dwc3_generic_runtime_resume(struct device *dev)
+{
+	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
+
+	return dwc3_runtime_resume(&dwc3->dwc);
+}
+
+static int dwc3_generic_runtime_idle(struct device *dev)
+{
+	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
+
+	return dwc3_runtime_idle(&dwc3->dwc);
+}
+
+static const struct dev_pm_ops dwc3_generic_dev_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(dwc3_generic_suspend, dwc3_generic_resume)
+	RUNTIME_PM_OPS(dwc3_generic_runtime_suspend, dwc3_generic_runtime_resume,
+		       dwc3_generic_runtime_idle)
+};
+
+static const struct of_device_id dwc3_generic_of_match[] = {
+	{ .compatible = "spacemit,k1-dwc3", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);
+
+static struct platform_driver dwc3_generic_driver = {
+	.probe		= dwc3_generic_probe,
+	.remove		= dwc3_generic_remove,
+	.driver		= {
+		.name	= "dwc3-generic-plat",
+		.of_match_table = dwc3_generic_of_match,
+		.pm	= pm_ptr(&dwc3_generic_dev_pm_ops),
+	},
+};
+module_platform_driver(dwc3_generic_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare USB3 generic platform driver");

-- 
2.50.1

Re: [PATCH v7 1/2] dt-bindings: usb: dwc3: add support for SpacemiT K1

[Yao Zi]

On Tue, Jul 29, 2025 at 12:33:55AM +0800, Ze Huang wrote:
> Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
> in the SpacemiT K1 SoC. The controller is based on the Synopsys
> DesignWare Core USB 3 (DWC3) IP, supporting USB3.0 host mode and USB 2.0
> DRD mode.
> 
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: Ze Huang <huang.ze@linux.dev>
> ---
>  .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++++++++
>  1 file changed, 124 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..7007e2bd42016ae0e50c4007e75d26bada34d983
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> @@ -0,0 +1,124 @@

...

> +  resets:
> +    items:
> +      - description: USB3.0 AHB reset
> +      - description: USB3.0 VCC reset
> +      - description: USB3.0 PHY reset
> +      - description: PCIE0 global reset (for combo phy)

Why should the USB driver takes care of the PCIe stuff? This sounds
strange to me.

> +  reset-names:
> +    items:
> +      - const: ahb
> +      - const: vcc
> +      - const: phy
> +      - const: pcie0

Best regards,
Yao Zi

Re: [PATCH v7 1/2] dt-bindings: usb: dwc3: add support for SpacemiT K1

[Ze Huang]

On Tue, Jul 29, 2025 at 01:41:01AM +0000, Yao Zi wrote:
> On Tue, Jul 29, 2025 at 12:33:55AM +0800, Ze Huang wrote:
> > Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
> > in the SpacemiT K1 SoC. The controller is based on the Synopsys
> > DesignWare Core USB 3 (DWC3) IP, supporting USB3.0 host mode and USB 2.0
> > DRD mode.
> > 
> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > Signed-off-by: Ze Huang <huang.ze@linux.dev>
> > ---
> >  .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++++++++
> >  1 file changed, 124 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..7007e2bd42016ae0e50c4007e75d26bada34d983
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> > @@ -0,0 +1,124 @@
> 
> ...
> 
> > +  resets:
> > +    items:
> > +      - description: USB3.0 AHB reset
> > +      - description: USB3.0 VCC reset
> > +      - description: USB3.0 PHY reset
> > +      - description: PCIE0 global reset (for combo phy)
> 
> Why should the USB driver takes care of the PCIe stuff? This sounds
> strange to me.
> 

On K1, PHY depends on the clocks and resets it shares with the controller,
and the controller driver is guarantees that any needed clocks are enabled,
and any resets that affect the PHY are de-asserted before using the PHY.

RESET_PCIE0_GLOBAL reset is necessary during, and only, the calibration stage
of combo phy.

To simplify both the driver architecture and the device tree files,
RESET_PCIE0_GLOBAL (and some other clk/reset) are now managed by the
relevant controller driver (either USB3 or PCIe0) instead of PHY driver.

Only one of USB3.0 SuperSpeed and PCIe-0 will be activated in a boot.
PCIe-0 will not be affected when it's working.



Hi Alex, please correct me if anything wrong

> > +  reset-names:
> > +    items:
> > +      - const: ahb
> > +      - const: vcc
> > +      - const: phy
> > +      - const: pcie0
> 
> Best regards,
> Yao Zi
> 
> 
> 

Re: [PATCH v7 1/2] dt-bindings: usb: dwc3: add support for SpacemiT K1

[Krzysztof Kozlowski]

On 29/07/2025 07:58, Ze Huang wrote:
> On Tue, Jul 29, 2025 at 01:41:01AM +0000, Yao Zi wrote:
>> On Tue, Jul 29, 2025 at 12:33:55AM +0800, Ze Huang wrote:
>>> Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
>>> in the SpacemiT K1 SoC. The controller is based on the Synopsys
>>> DesignWare Core USB 3 (DWC3) IP, supporting USB3.0 host mode and USB 2.0
>>> DRD mode.
>>>
>>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>> Signed-off-by: Ze Huang <huang.ze@linux.dev>
>>> ---
>>>  .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++++++++
>>>  1 file changed, 124 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
>>> new file mode 100644
>>> index 0000000000000000000000000000000000000000..7007e2bd42016ae0e50c4007e75d26bada34d983
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
>>> @@ -0,0 +1,124 @@
>>
>> ...
>>
>>> +  resets:
>>> +    items:
>>> +      - description: USB3.0 AHB reset
>>> +      - description: USB3.0 VCC reset
>>> +      - description: USB3.0 PHY reset
>>> +      - description: PCIE0 global reset (for combo phy)
>>
>> Why should the USB driver takes care of the PCIe stuff? This sounds
>> strange to me.
>>
> 
> On K1, PHY depends on the clocks and resets it shares with the controller,
> and the controller driver is guarantees that any needed clocks are enabled,
> and any resets that affect the PHY are de-asserted before using the PHY.
> 
> RESET_PCIE0_GLOBAL reset is necessary during, and only, the calibration stage
> of combo phy.


But this is not PCI! Why would you call it "I need to reset PCI" while
you describe the USB device?


Best regards,
Krzysztof

Re: [PATCH v7 1/2] dt-bindings: usb: dwc3: add support for SpacemiT K1

[Yao Zi]

On Tue, Jul 29, 2025 at 01:58:12PM +0800, Ze Huang wrote:
> On Tue, Jul 29, 2025 at 01:41:01AM +0000, Yao Zi wrote:
> > On Tue, Jul 29, 2025 at 12:33:55AM +0800, Ze Huang wrote:
> > > Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
> > > in the SpacemiT K1 SoC. The controller is based on the Synopsys
> > > DesignWare Core USB 3 (DWC3) IP, supporting USB3.0 host mode and USB 2.0
> > > DRD mode.
> > > 
> > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > > Signed-off-by: Ze Huang <huang.ze@linux.dev>
> > > ---
> > >  .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 124 +++++++++++++++++++++
> > >  1 file changed, 124 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> > > new file mode 100644
> > > index 0000000000000000000000000000000000000000..7007e2bd42016ae0e50c4007e75d26bada34d983
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
> > > @@ -0,0 +1,124 @@
> > 
> > ...
> > 
> > > +  resets:
> > > +    items:
> > > +      - description: USB3.0 AHB reset
> > > +      - description: USB3.0 VCC reset
> > > +      - description: USB3.0 PHY reset
> > > +      - description: PCIE0 global reset (for combo phy)
> > 
> > Why should the USB driver takes care of the PCIe stuff? This sounds
> > strange to me.
> > 
> 
> On K1, PHY depends on the clocks and resets it shares with the controller,
> and the controller driver is guarantees that any needed clocks are enabled,
> and any resets that affect the PHY are de-asserted before using the PHY.

So does the "PCIe0 global reset" make effects to both USB3 and PCIe
**controllers**? If not, this is something wrong in the devicetree side.

> RESET_PCIE0_GLOBAL reset is necessary during, and only, the calibration stage
> of combo phy.

If it's only used by PHY, why couldn't it be a property of the PHY?
Sorry, but I still cannot get the point.

Regards,
Yao Zi

> To simplify both the driver architecture and the device tree files,
> RESET_PCIE0_GLOBAL (and some other clk/reset) are now managed by the
> relevant controller driver (either USB3 or PCIe0) instead of PHY driver.
> 
> Only one of USB3.0 SuperSpeed and PCIe-0 will be activated in a boot.
> PCIe-0 will not be affected when it's working.

Re: [PATCH v7 2/2] usb: dwc3: add generic driver to support flattened

[Thinh Nguyen]

On Tue, Jul 29, 2025, Ze Huang wrote:
> To support flattened dwc3 dt model and drop the glue layer, introduce the
> `dwc3-generic` driver. This enables direct binding of the DWC3 core driver
> and offers an alternative to the existing glue driver `dwc3-of-simple`.
> 
> Signed-off-by: Ze Huang <huang.ze@linux.dev>
> ---
>  drivers/usb/dwc3/Kconfig             |  11 +++
>  drivers/usb/dwc3/Makefile            |   1 +
>  drivers/usb/dwc3/dwc3-generic-plat.c | 167 +++++++++++++++++++++++++++++++++++
>  3 files changed, 179 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 310d182e10b50b253d7e5a51674806e6ec442a2a..4925d15084f816d3ff92059b476ebcc799b56b51 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -189,4 +189,15 @@ config USB_DWC3_RTK
>  	  or dual-role mode.
>  	  Say 'Y' or 'M' if you have such device.
>  
> +config USB_DWC3_GENERIC_PLAT
> +	tristate "DWC3 Generic Platform Driver"
> +	depends on OF && COMMON_CLK
> +	default USB_DWC3
> +	help
> +	  Support USB3 functionality in simple SoC integrations.
> +	  Currently supports SpacemiT DWC USB3. Platforms using
> +	  dwc3-of-simple can easily switch to dwc3-generic by flattening
> +	  the dwc3 child node in the device tree.
> +	  Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> +
>  endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 830e6c9e5fe073c1f662ce34b6a4a2da34c407a2..96469e48ff9d189cc8d0b65e65424eae2158bcfe 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -57,3 +57,4 @@ obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
>  obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>  obj-$(CONFIG_USB_DWC3_OCTEON)		+= dwc3-octeon.o
>  obj-$(CONFIG_USB_DWC3_RTK)		+= dwc3-rtk.o
> +obj-$(CONFIG_USB_DWC3_GENERIC_PLAT)	+= dwc3-generic-plat.o
> diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..abb144867bf5f678223483c948521ceb44d05190
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-generic-plat.c
> @@ -0,0 +1,167 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * dwc3-generic-plat.c - DesignWare USB3 generic platform driver
> + *
> + * Copyright (C) 2025 Ze Huang <huang.ze@linux.dev>
> + *
> + * Inspired by dwc3-qcom.c and dwc3-of-simple.c
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include "glue.h"
> +
> +struct dwc3_generic {
> +	struct device		*dev;
> +	struct dwc3		dwc;
> +	struct clk_bulk_data	*clks;
> +	int			num_clocks;
> +	struct reset_control	*resets;
> +};
> +
> +static void dwc3_generic_reset_control_assert(void *data)
> +{
> +	reset_control_assert(data);
> +}
> +
> +static int dwc3_generic_probe(struct platform_device *pdev)
> +{
> +	struct dwc3_probe_data probe_data = {};
> +	struct device *dev = &pdev->dev;
> +	struct dwc3_generic *dwc3;
> +	struct resource *res;
> +	int ret;
> +
> +	dwc3 = devm_kzalloc(dev, sizeof(*dwc3), GFP_KERNEL);
> +	if (!dwc3)
> +		return -ENOMEM;
> +
> +	dwc3->dev = dev;
> +
> +	platform_set_drvdata(pdev, dwc3);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "missing memory resource\n");
> +		return -ENODEV;
> +	}
> +
> +	dwc3->resets = devm_reset_control_array_get_optional_exclusive(dev);
> +	if (IS_ERR(dwc3->resets))
> +		return dev_err_probe(dev, PTR_ERR(dwc3->resets), "failed to get resets\n");
> +
> +	ret = reset_control_assert(dwc3->resets);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to assert resets\n");
> +
> +	/* Not strict timing, just for safety */
> +	udelay(2);
> +
> +	ret = reset_control_deassert(dwc3->resets);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to deassert resets\n");
> +
> +	ret = devm_add_action_or_reset(dev, dwc3_generic_reset_control_assert, dwc3->resets);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_clk_bulk_get_all_enabled(dwc3->dev, &dwc3->clks);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "failed to get clocks\n");
> +
> +	dwc3->num_clocks = ret;
> +	dwc3->dwc.dev = dev;
> +	probe_data.dwc = &dwc3->dwc;
> +	probe_data.res = res;
> +	probe_data.ignore_clocks_and_resets = true;
> +	ret = dwc3_core_probe(&probe_data);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
> +
> +	return 0;
> +}
> +
> +static void dwc3_generic_remove(struct platform_device *pdev)
> +{
> +	struct dwc3_generic *dwc3 = platform_get_drvdata(pdev);
> +
> +	dwc3_core_remove(&dwc3->dwc);
> +}
> +
> +static int dwc3_generic_suspend(struct device *dev)
> +{
> +	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = dwc3_pm_suspend(&dwc3->dwc);
> +	if (ret)
> +		return ret;
> +
> +	clk_bulk_disable_unprepare(dwc3->num_clocks, dwc3->clks);
> +
> +	return 0;
> +}
> +
> +static int dwc3_generic_resume(struct device *dev)
> +{
> +	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = clk_bulk_prepare_enable(dwc3->num_clocks, dwc3->clks);
> +	if (ret)
> +		return ret;
> +
> +	ret = dwc3_pm_resume(&dwc3->dwc);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int dwc3_generic_runtime_suspend(struct device *dev)
> +{
> +	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
> +
> +	return dwc3_runtime_suspend(&dwc3->dwc);
> +}
> +
> +static int dwc3_generic_runtime_resume(struct device *dev)
> +{
> +	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
> +
> +	return dwc3_runtime_resume(&dwc3->dwc);
> +}
> +
> +static int dwc3_generic_runtime_idle(struct device *dev)
> +{
> +	struct dwc3_generic *dwc3 = dev_get_drvdata(dev);
> +
> +	return dwc3_runtime_idle(&dwc3->dwc);
> +}
> +
> +static const struct dev_pm_ops dwc3_generic_dev_pm_ops = {
> +	SYSTEM_SLEEP_PM_OPS(dwc3_generic_suspend, dwc3_generic_resume)
> +	RUNTIME_PM_OPS(dwc3_generic_runtime_suspend, dwc3_generic_runtime_resume,
> +		       dwc3_generic_runtime_idle)
> +};
> +
> +static const struct of_device_id dwc3_generic_of_match[] = {
> +	{ .compatible = "spacemit,k1-dwc3", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);
> +
> +static struct platform_driver dwc3_generic_driver = {
> +	.probe		= dwc3_generic_probe,
> +	.remove		= dwc3_generic_remove,
> +	.driver		= {
> +		.name	= "dwc3-generic-plat",
> +		.of_match_table = dwc3_generic_of_match,
> +		.pm	= pm_ptr(&dwc3_generic_dev_pm_ops),
> +	},
> +};
> +module_platform_driver(dwc3_generic_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("DesignWare USB3 generic platform driver");
> 
> -- 
> 2.50.1
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh