usb: cdns3: USBSSP platform driver support

This series adds platform driver support for the Cadence USBSSP (CDNSP) controller, which was previously only accessible through PCI. The USBSSP controller is auto-detected at runtime by reading the DRD/OTG Device ID register; both USBSS and USBSSP use the "cdns,usb3" compatible string (binding update in patch 1).

Changes since v2 (vs the v2 series on list)

v2 split CONFIG_USB_CDNSP into its own cdnsp.ko-style path and built cdns3-plat as a standalone module next to cdns-usb-common. v3 folds the integration back into one driver module:

- Single cdns.ko (CONFIG_USB_CDNS3) bundles core, DRD, the generic cdns3-plat binding, optional host.o (CONFIG_USB_CDNS3_HOST) and optional gadget objects (CONFIG_USB_CDNS3_GADGET). SoC and PCI glue stay separate small .ko files.

- CONFIG_USB_CDNS_SUPPORT depends on USB and USB_GADGET using the usual pattern (depends on USB || USB_GADGET; depends on USB if !USB_GADGET; depends on USB_GADGET if !USB) so the umbrella tracks host or gadget when either is built as a module (Suggested-by: Arnd Bergmann).

- USB_CDNS3_HOST / USB_CDNS3_GADGET are matched to the cdns.ko tristate with USB=USB_CDNS3 and USB_GADGET=USB_CDNS3 instead of tying gadget only to CONFIG_USB_CDNS_SUPPORT, which mis-handled =y / =m splits when CONFIG_USB_CDNS_SUPPORT=y but CONFIG_USB_CDNS3=m.

- Drop CONFIG_USB_CDNS_HOST; Makefile and host-export.h use CONFIG_USB_CDNS3_HOST only.

- gadget-export.h uses IS_ENABLED(CONFIG_USB_CDNS3_GADGET) for stubs now that gadget is a bool compiled into the unified module (v2 used IS_REACHABLE on separate CONFIG_USB_CDNS3 / CONFIG_USB_CDNSP tristates).

- Patch 2 still refactors cdnsp-pci.c into a PCI-to-platform wrapper, keeps host_init / gadget_init callbacks, exports cdns_core_init_role, and limits drivers/usb/cdns3/ to CONFIG_USB_CDNS_SUPPORT.

- Add Rob Herring's ACK for Patch 1.

Build verification

Exhaustive Kconfig sweep: 79 unique resolved configurations (deduped on CONFIG_USB, CONFIG_USB_GADGET, CONFIG_USB_CDNS_SUPPORT, CONFIG_USB_CDNS3_HOST, CONFIG_USB_CDNS3, CONFIG_USB_CDNSP_PCI, CONFIG_USB_CDNS3_GADGET), arm64 cross-build, each run through make O=out/cix olddefconfig, then Image + modules, then modules_install into a clean INSTALL_MOD_PATH:

PASS 79 / 79; build failures 0; depmod / module graph failures 0.

Peter Chen (2):
dt-bindings: usb: cdns,usb3: document USBSSP controller support
usb: cdns3: Add USBSSP platform driver support

 .../devicetree/bindings/usb/cdns,usb3.yaml    |  10 +-
 drivers/usb/Makefile                          |   2 -
 drivers/usb/cdns3/Kconfig                     | 112 ++++-----
 drivers/usb/cdns3/Makefile                    |  44 ++--
 drivers/usb/cdns3/cdns3-gadget.c              |   1 +
 drivers/usb/cdns3/cdns3-plat.c                |  27 ++-
 drivers/usb/cdns3/cdnsp-gadget.c              |   1 +
 drivers/usb/cdns3/cdnsp-pci.c                 | 217 ++++++++----------
 drivers/usb/cdns3/core.c                      |  45 ++--
 drivers/usb/cdns3/core.h                      |   5 +-
 drivers/usb/cdns3/gadget-export.h             |  10 +-
 drivers/usb/cdns3/host-export.h               |   4 +-
 12 files changed, 209 insertions(+), 269 deletions(-)

2.50.1

Update the Cadence USBSS DRD binding to document that it also covers the USBSSP (SuperSpeed Plus, USB 3.1 gen2x1) controller. Both USBSS and USBSSP share the same DRD/OTG register interface, so the driver auto-detects the controller version at runtime: no additional compatible string is needed.

Changes to the binding:
- Update title and add description
- maximum-speed: add super-speed-plus

---
 Documentation/devicetree/bindings/usb/cdns,usb3.yaml | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

index f454ddd9bbaa..ad5acf956edf 100644
@@ -4,11 +4,17 @@
 $id: http://devicetree.org/schemas/usb/cdns,usb3.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Cadence USBSS-DRD controller
+title: Cadence USBSS and USBSSP DRD controller
 
 maintainers:
   - Pawel Laszczak <[email protected]>
 
+description:
+  Cadence USB dual-role controller. Covers USBSS (SuperSpeed, USB 3.0) and
+  USBSSP (SuperSpeed Plus, USB 3.1 gen2x1). Both variants share the same
+  DRD/OTG register interface, so the driver auto-detects the controller
+  version at runtime.
+
 properties:
   compatible:
     const: cdns,usb3

@@ -49,7 +55,7 @@ properties:
       cdns3 to type C connector.
 
   maximum-speed:
-    enum: [super-speed, high-speed, full-speed]
+    enum: [super-speed-plus, super-speed, high-speed, full-speed]
 
   phys:
     minItems: 1

2.50.1

Expose Cadence USBSSP through the same platform path as USBSS, trim Kconfig and Makefile: one core loadable object plus separate glue .ko files.

Single cdns.ko bundles core, DRD, the generic "cdns,usb3" platform driver in cdns3-plat.c, optional host.o, and optional gadget objects. Use CONFIG_USB_CDNS3_GADGET as a bool to compile gadget support into that module. Remove duplicate MODULE_* declarations from cdns3-plat.c now that it links into the same module.

Kconfig: the generic platform driver is selected via CONFIG_USB_CDNS3. Move CONFIG_USB_CDNSP_PCI beside CONFIG_USB_CDNS3_PCI_WRAP under "Platform glue driver support". SoC glue entries (TI, i.MX, StarFive) depend only on CONFIG_USB_CDNS3.

Tighten CONFIG_USB_CDNS_SUPPORT dependencies so the umbrella follows host or gadget when either is built as a module. Match host and gadget bools to the cdns.ko tristate with USB=USB_CDNS3 and USB_GADGET=USB_CDNS3 instead of comparing against USB_CDNS_SUPPORT.

Link host.o when CONFIG_USB_CDNS3_HOST is enabled and use that symbol in host-export.h, removing the redundant CONFIG_USB_CDNS_HOST indirection.

Export cdns_core_init_role and reorganize the function cdns_init, and controller version could be gotten before the gadget init function is decided per controller.

Keep host_init / gadget_init callbacks in struct cdns, so core.c does not need direct linkage to host or gadget objects. Refactor cdnsp-pci.c into a thin PCI-to-platform wrapper.

drivers/usb/Makefile: descend into drivers/usb/cdns3/ only when CONFIG_USB_CDNS_SUPPORT is enabled.

---
 drivers/usb/Makefile              |   2 -
 drivers/usb/cdns3/Kconfig         | 112 +++++++--------
 drivers/usb/cdns3/Makefile        |  44 +++---
 drivers/usb/cdns3/cdns3-gadget.c  |   1 +
 drivers/usb/cdns3/cdns3-plat.c    |  27 +++-
 drivers/usb/cdns3/cdnsp-gadget.c  |   1 +
 drivers/usb/cdns3/cdnsp-pci.c     | 217 +++++++++++++-----------------
 drivers/usb/cdns3/core.c          |  45 ++-----
 drivers/usb/cdns3/core.h          |   5 +-
 drivers/usb/cdns3/gadget-export.h |  10 +-
 drivers/usb/cdns3/host-export.h   |   4 +-
 11 files changed, 201 insertions(+), 267 deletions(-)

index 6f3c86149887..eecbd631fdab 100644
@@ -14,8 +14,6 @@ obj-$(CONFIG_USB_DWC2)		+= dwc2/
 obj-$(CONFIG_USB_ISP1760)	+= isp1760/
 
 obj-$(CONFIG_USB_CDNS_SUPPORT)	+= cdns3/
-obj-$(CONFIG_USB_CDNS3)		+= cdns3/
-obj-$(CONFIG_USB_CDNSP_PCI)	+= cdns3/
 
 obj-$(CONFIG_USB_FOTG210)	+= fotg210/
 

index d59a60a16ec7..ff422e5204e4 100644
@@ -3508,3 +3508,4 @@ int cdns3_gadget_init(struct cdns *cdns)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(cdns3_gadget_init);

index 735df88774e4..3fe3109a3688 100644
@@ -21,6 +21,7 @@
 
 #include "core.h"
 #include "gadget-export.h"
+#include "host-export.h"
 #include "drd.h"
 
 static int set_phy_power_on(struct cdns *cdns)

@@ -44,6 +45,19 @@ static void set_phy_power_off(struct cdns *cdns)
 	phy_power_off(cdns->usb2_phy);
 }
 
+static int cdns3_plat_gadget_init(struct cdns *cdns)
+{
+	if (cdns->version < CDNSP_CONTROLLER_V2)
+		return cdns3_gadget_init(cdns);
+	else
+		return cdnsp_gadget_init(cdns);
+}
+
+static int cdns3_plat_host_init(struct cdns *cdns)
+{
+	return cdns_host_init(cdns);
+}
+
 /**
  * cdns3_plat_probe - probe for cdns3 core device
  * @pdev: Pointer to cdns3 core platform device

@@ -64,6 +78,8 @@ static int cdns3_plat_probe(struct platform_device *pdev)
 
 	cdns->dev = dev;
 	cdns->pdata = dev_get_platdata(dev);
+	if (cdns->pdata && cdns->pdata->override_apb_timeout)
+		cdns->override_apb_timeout = cdns->pdata->override_apb_timeout;
 
 	platform_set_drvdata(pdev, cdns);
 

@@ -143,12 +159,16 @@ static int cdns3_plat_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_phy_power_on;
 
-	cdns->gadget_init = cdns3_gadget_init;
-
 	ret = cdns_init(cdns);
 	if (ret)
 		goto err_cdns_init;
 
+	cdns->gadget_init = cdns3_plat_gadget_init;
+	cdns->host_init = cdns3_plat_host_init;
+	ret = cdns_core_init_role(cdns);
+	if (ret)
+		goto err_cdns_init;
+
 	device_set_wakeup_capable(dev, true);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);

@@ -336,6 +356,3 @@ static struct platform_driver cdns3_driver = {
 module_platform_driver(cdns3_driver);
 
 MODULE_ALIAS("platform:cdns3");
-MODULE_AUTHOR("Pawel Laszczak <[email protected]>");
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");

index 6b3815f8a6e5..18e872ad29bd 100644
@@ -2075,3 +2075,4 @@ int cdnsp_gadget_init(struct cdns *cdns)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(cdnsp_gadget_init);

index 801be9e61340..bca973b999a4 100644
@@ -45,6 +45,7 @@ struct cdns3_platform_data {
 	unsigned long quirks;
 #define CDNS3_DEFAULT_PM_RUNTIME_ALLOW	BIT(0)
 #define CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE	BIT(1)
+	u32 override_apb_timeout;	/* 0 = use default (e.g. for PCI) */
 };
 
 /**

@@ -82,6 +83,7 @@ struct cdns3_platform_data {
  * @override_apb_timeout: hold value of APB timeout. For value 0 the default
  *                        value in CHICKEN_BITS_3 will be preserved.
  * @gadget_init: pointer to gadget initialization function
+ * @host_init: pointer to host initialization function
  */
 struct cdns {
 	struct device			*dev;

@@ -120,13 +122,14 @@ struct cdns {
 	spinlock_t			lock;
 	struct xhci_plat_priv		*xhci_plat_data;
 	u32                             override_apb_timeout;
-
 	int (*gadget_init)(struct cdns *cdns);
+	int (*host_init)(struct cdns *cdns);
 };
 
 int cdns_hw_role_switch(struct cdns *cdns);
 int cdns_init(struct cdns *cdns);
 int cdns_remove(struct cdns *cdns);
+int cdns_core_init_role(struct cdns *cdns);
 
 #ifdef CONFIG_PM_SLEEP
 int cdns_resume(struct cdns *cdns);

index c37b6269b001..60c3177db62c 100644
@@ -10,9 +10,10 @@
 #ifndef __LINUX_CDNS3_GADGET_EXPORT
 #define __LINUX_CDNS3_GADGET_EXPORT
 
-#if IS_ENABLED(CONFIG_USB_CDNSP_GADGET)
+#if IS_ENABLED(CONFIG_USB_CDNS3_GADGET)
 
 int cdnsp_gadget_init(struct cdns *cdns);
+int cdns3_gadget_init(struct cdns *cdns);
 #else
 
 static inline int cdnsp_gadget_init(struct cdns *cdns)

@@ -20,13 +21,6 @@ static inline int cdnsp_gadget_init(struct cdns *cdns)
 	return -ENXIO;
 }
 
-#endif /* CONFIG_USB_CDNSP_GADGET */
-
-#if IS_ENABLED(CONFIG_USB_CDNS3_GADGET)
-
-int cdns3_gadget_init(struct cdns *cdns);
-#else
-
 static inline int cdns3_gadget_init(struct cdns *cdns)
 {
 	return -ENXIO;

index cf92173ecf00..34fd1f1ad59d 100644
@@ -9,7 +9,7 @@
 #ifndef __LINUX_CDNS3_HOST_EXPORT
 #define __LINUX_CDNS3_HOST_EXPORT
 
-#if IS_ENABLED(CONFIG_USB_CDNS_HOST)
+#if IS_ENABLED(CONFIG_USB_CDNS3_HOST)
 
 int cdns_host_init(struct cdns *cdns);
 

@@ -22,6 +22,6 @@ static inline int cdns_host_init(struct cdns *cdns)
 
 static inline void cdns_host_exit(struct cdns *cdns) { }
 
-#endif /* USB_CDNS_HOST */
+#endif /* CONFIG_USB_CDNS3_HOST */
 
 #endif /* __LINUX_CDNS3_HOST_EXPORT */

2.50.1

This looks fine to me,

I've added the patch to my randconfig build setup now, to see if there are any corner cases left that I have missed where it may still get into a build time failure and will let you know if I find any.

Arnd

Thanks, Arnd.

Best regards,
Peter