[PATCH v8 0/2] Add Google Tensor SoC USB controller support

[PATCH v8 0/2] Add Google Tensor SoC USB controller support

[Roy Luo]

This series introduces USB controller support for the Google Tensor G5
SoC (codename: Laguna), a new generation of Google silicon first
launched with Pixel 10 devices.

The Tensor G5 represents a significant architectural overhaul compared
to previous Tensor generations (e.g., gs101), which were based on Samsung
Exynos IP. Although the G5 still utilizes Synopsys IP for the USB
components, the custom top-level integration introduces a completely new
design for clock, reset scheme, register interfaces and programming
sequence, necessitating new drivers and device tree bindings.

The USB subsystem on Tensor G5 integrates a Synopsys DWC3 USB 3.1
DRD-Single Port controller with hibernation support, and a custom PHY
block comprising Synopsys eUSB2 and USB 3.2/DP combo PHYs. The PHY
support is sent as a separate patch series.

Co-developed-by: Joy Chakraborty <joychakr@google.com>
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Co-developed-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Roy Luo <royluo@google.com>
---
Changes in v8:
- Add COMPILE_TEST to dependencies for build coverage.
- Drop redundant default n in Kconfig.
- Update Kconfig help text to explicitly state the module name.
- Use container_of_const() in the to_dwc3_google() macro for type safety.
Link to v7: https://lore.kernel.org/linux-usb/20251119093749.292926-1-royluo@google.com

Changes in v7:
- Follow driver naming convention and rename the driver as "dwc3-google".
Link to v6: https://lore.kernel.org/linux-usb/20251112123257.3755489-1-royluo@google.com

Changes in v6:
- Use "lga" as SoC name instead of "gs5" to align with Tensor G5 device
  tree https://lore.kernel.org/lkml/20251111192422.4180216-1-dianders@chromium.org
Link to v5: https://lore.kernel.org/linux-usb/20251111130624.3069704-1-royluo@google.com

Changes in v5:
- Use syscon to access host_cfg and usbint_cfg MMIO space per
  discussion in https://lore.kernel.org/linux-phy/89733ddf-8af3-42d0-b6e5-20b7a4ef588c@kernel.org
- Make warn logs in dwc3_google_resume_irq() dev_dbg.
Link to v4: https://lore.kernel.org/linux-usb/20251017233459.2409975-1-royluo@google.com

Changes in v4:
- Separate controller and phy changes into two distinct patch series.
- Rename dwc3 core interrupt as "core".
- Remove u2phy_apb clk/reset (moved to PHY)
- Configure usb2only mode when usb3 phy is not present.
- Adopt pm_ptr PM macros to fix build warnings.
Link to v3: https://lore.kernel.org/linux-usb/20251010201607.1190967-1-royluo@google.com

Changes in v3:
- Align binding file name with the compatible string
- Simplify the compatible property in binding to a single const value.
- Add descriptive comments and use item list in binding.
- Rename binding entries for clarity and brevity.
Link to v2: https://lore.kernel.org/linux-usb/20251008060000.3136021-1-royluo@google.com

Changes in v2:
- Reorder patches to present bindings first.
- Update dt binding compatible strings to be SoC-specific (google,gs5-*).
- Better describe the hardware in dt binding commit messages and
  descriptions.
- Adjust PHY driver commit subjects to use correct prefixes ("phy:").
- Move PHY driver from a subdirectory to drivers/phy/.
Link to v1: https://lore.kernel.org/linux-usb/20251006232125.1833979-1-royluo@google.com/

---
Roy Luo (2):
      dt-bindings: usb: dwc3: Add Google Tensor G5 DWC3
      usb: dwc3: Add Google Tensor SoC DWC3 glue driver

 .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++
 drivers/usb/dwc3/Kconfig                           |  13 +
 drivers/usb/dwc3/Makefile                          |   1 +
 drivers/usb/dwc3/dwc3-google.c                     | 628 +++++++++++++++++++++
 4 files changed, 782 insertions(+)
---
base-commit: 8b690556d8fe074b4f9835075050fba3fb180e93
change-id: 20251122-controller-129b0dd57a74

Best regards,
-- 
Roy Luo <royluo@google.com>

[PATCH v8 1/2] dt-bindings: usb: dwc3: Add Google Tensor G5 DWC3

[Roy Luo]

Document the device tree bindings for the DWC3 USB controller found in
Google Tensor SoCs, starting with the G5 generation (codename: laguna).

The Tensor G5 silicon represents a complete architectural departure from
previous generations (like gs101), including entirely new clock/reset
schemes, top-level wrapper and register interface. Consequently,
existing Samsung/Exynos DWC3 USB bindings are incompatible, necessitating
this new device tree binding.

The USB controller on Tensor G5 is based on Synopsys DWC3 IP and features
Dual-Role Device single port with hibernation support.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Roy Luo <royluo@google.com>
---
 .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
 1 file changed, 140 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml b/Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..95be84c843f5da0e80ef5ef1ac9193019b5eb2a0
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
@@ -0,0 +1,140 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (c) 2025, Google LLC
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/google,lga-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Tensor Series G5 (Laguna) DWC3 USB SoC Controller
+
+maintainers:
+  - Roy Luo <royluo@google.com>
+
+description:
+  Describes the DWC3 USB controller block implemented on Google Tensor SoCs,
+  starting with the G5 generation (laguna). Based on Synopsys DWC3 IP, the
+  controller features Dual-Role Device single port with hibernation add-on.
+
+properties:
+  compatible:
+    const: google,lga-dwc3
+
+  reg:
+    items:
+      - description: Core DWC3 IP registers.
+
+  interrupts:
+    items:
+      - description: Core DWC3 interrupt.
+      - description: High speed power management event for remote wakeup.
+      - description: Super speed power management event for remote wakeup.
+
+  interrupt-names:
+    items:
+      - const: core
+      - const: hs_pme
+      - const: ss_pme
+
+  clocks:
+    items:
+      - description: Non-sticky module clock.
+      - description: Sticky module clock.
+
+  clock-names:
+    items:
+      - const: non_sticky
+      - const: sticky
+
+  resets:
+    items:
+      - description: Non-sticky module reset.
+      - description: Sticky module reset.
+      - description: DRD bus reset.
+      - description: Top-level reset.
+
+  reset-names:
+    items:
+      - const: non_sticky
+      - const: sticky
+      - const: drd_bus
+      - const: top
+
+  power-domains:
+    items:
+      - description: Power switchable domain, the child of top domain.
+          Turning it on puts the controller into full power state,
+          turning it off puts the controller into power gated state.
+      - description: Top domain, the parent of power switchable domain.
+          Turning it on puts the controller into power gated state,
+          turning it off completely shuts off the controller.
+
+  power-domain-names:
+    items:
+      - const: psw
+      - const: top
+
+  iommus:
+    maxItems: 1
+
+  google,usb-cfg-csr:
+    description:
+      A phandle to a syscon node used to access the USB configuration
+      registers. These registers are the top-level wrapper of the USB
+      subsystem and provide control and status for the integrated USB
+      controller and USB PHY.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to the syscon node.
+          - description: USB host controller configuration register offset.
+          - description: USB custom interrrupts control register offset.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - power-domains
+  - power-domain-names
+  - google,usb-cfg-csr
+
+allOf:
+  - $ref: snps,dwc3-common.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        usb@c400000 {
+            compatible = "google,lga-dwc3";
+            reg = <0 0x0c400000  0 0xd060>;
+            interrupts = <GIC_SPI 580 IRQ_TYPE_LEVEL_HIGH 0>,
+                         <GIC_SPI 597 IRQ_TYPE_LEVEL_HIGH 0>,
+                         <GIC_SPI 598 IRQ_TYPE_LEVEL_HIGH 0>;
+            interrupt-names = "core", "hs_pme", "ss_pme";
+            clocks = <&hsion_usbc_non_sticky_clk>,  <&hsion_usbc_sticky_clk>;
+            clock-names = "non_sticky", "sticky";
+            resets = <&hsion_resets_usbc_non_sticky>, <&hsion_resets_usbc_sticky>,
+                     <&hsion_resets_usb_drd_bus>, <&hsion_resets_usb_top>;
+            reset-names = "non_sticky", "sticky", "drd_bus", "top";
+            power-domains = <&hsio_n_usb_psw>, <&hsio_n_usb>;
+            power-domain-names = "psw", "top";
+            phys = <&usb_phy 0>;
+            phy-names = "usb2-phy";
+            snps,quirk-frame-length-adjustment = <0x20>;
+            snps,gfladj-refclk-lpm-sel-quirk;
+            snps,incr-burst-type-adjustment = <4>;
+            google,usb-cfg-csr = <&usb_cfg_csr 0x0 0x20>;
+        };
+    };
+...

-- 
2.52.0.rc2.455.g230fcf2819-goog

[PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

Add support for the DWC3 USB controller found on Google Tensor G5
(codename: laguna). The controller features dual-role functionality
and hibernation.

The primary focus is implementing hibernation support in host mode,
enabling the controller to enter a low-power state (D3). This is
particularly relevant during system power state transition and
runtime power management for power efficiency.
Highlights:
- Align suspend callback with dwc3_suspend_common() for deciding
  between a full teardown and hibernation in host mode.
- Integration with `psw` (power switchable) and `top` power domains,
  managing their states and device links to support hibernation.
- A notifier callback dwc3_google_usb_psw_pd_notifier() for
  `psw` power domain events to manage controller state
  transitions to/from D3.
- Coordination of the `non_sticky` reset during power state
  transitions, asserting it on D3 entry and deasserting on D0 entry
  in hibernation scenario.
- Handling of high-speed and super-speed PME interrupts
  that are generated by remote wakeup during hibernation.

Co-developed-by: Joy Chakraborty <joychakr@google.com>
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Co-developed-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Roy Luo <royluo@google.com>
---
 drivers/usb/dwc3/Kconfig       |  13 +
 drivers/usb/dwc3/Makefile      |   1 +
 drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 642 insertions(+)

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
 	  the dwc3 child node in the device tree.
 	  Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
 
+config USB_DWC3_GOOGLE
+	tristate "Google Platform"
+	depends on COMPILE_TEST
+	depends on OF && COMMON_CLK && RESET_CONTROLLER
+	help
+	  Support the DesignWare Core USB3 IP found on Google Tensor
+	  SoCs, starting with the G5 generation. This driver includes
+	  support for hibernation in host mode.
+	  Say 'Y' or 'M' if you have one such device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called dwc3-google.ko.
+
 endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 96469e48ff9d189cc8d0b65e65424eae2158bcfe..cf1cd408d938b3ac26d58b9be7fcc5af3ee82660 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -58,3 +58,4 @@ 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
+obj-$(CONFIG_USB_DWC3_GOOGLE)		+= dwc3-google.o
diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
new file mode 100644
index 0000000000000000000000000000000000000000..53e04a5409d8a11eb025b0f5cd351cb1b33281ab
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-google.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwc3-google.c - Google DWC3 Specific Glue Layer
+ *
+ * Copyright (c) 2025, Google LLC
+ * Author: Roy Luo <royluo@google.com>
+ */
+
+#include <linux/of.h>
+#include <linux/bitfield.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/pm_domain.h>
+#include <linux/iopoll.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include "core.h"
+#include "glue.h"
+
+/* HOST CFG registers */
+#define HC_STATUS_OFFSET 0x0
+#define HC_STATUS_CURRENT_POWER_STATE_U2PMU GENMASK(1, 0)
+#define HC_STATUS_CURRENT_POWER_STATE_U3PMU GENMASK(4, 3)
+
+#define HOST_CFG1_OFFSET 0x4
+#define HOST_CFG1_PME_EN BIT(3)
+#define HOST_CFG1_PM_POWER_STATE_REQUEST GENMASK(5, 4)
+#define HOST_CFG1_PM_POWER_STATE_D0 0x0
+#define HOST_CFG1_PM_POWER_STATE_D3 0x3
+
+/* USBINT registers */
+#define USBINT_CFG1_OFFSET 0x0
+#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK BIT(2)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK BIT(3)
+#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN BIT(8)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN BIT(9)
+#define USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR BIT(14)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR BIT(15)
+
+#define USBINT_STATUS_OFFSET 0x4
+#define USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW BIT(2)
+#define USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW BIT(3)
+
+#define USBCS_TOP_CTRL_CFG1_OFFSET 0xc
+#define USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE BIT(5)
+
+#define DWC3_GOOGLE_MAX_RESETS	4
+
+struct dwc3_google {
+	struct device		*dev;
+	struct dwc3		dwc;
+	struct clk_bulk_data	*clks;
+	int			num_clks;
+	struct reset_control_bulk_data rsts[DWC3_GOOGLE_MAX_RESETS];
+	int			num_rsts;
+	struct reset_control	*non_sticky_rst;
+	struct device		*usb_psw_pd;
+	struct device_link	*usb_psw_pd_dl;
+	struct notifier_block	usb_psw_pd_nb;
+	struct device		*usb_top_pd;
+	struct device_link	*usb_top_pd_dl;
+	struct regmap		*usb_cfg_regmap;
+	unsigned int		host_cfg_offset;
+	unsigned int		usbint_cfg_offset;
+	int			hs_pme_irq;
+	int			ss_pme_irq;
+	bool			is_usb2only;
+	bool			is_hibernation;
+};
+
+#define to_dwc3_google(d) container_of_const((d), struct dwc3_google, dwc)
+
+static int dwc3_google_rst_init(struct dwc3_google *google)
+{
+	int ret;
+
+	google->num_rsts = 4;
+	google->rsts[0].id = "non_sticky";
+	google->rsts[1].id = "sticky";
+	google->rsts[2].id = "drd_bus";
+	google->rsts[3].id = "top";
+
+	ret = devm_reset_control_bulk_get_exclusive(google->dev,
+						    google->num_rsts,
+						    google->rsts);
+
+	if (ret < 0)
+		return ret;
+
+	google->non_sticky_rst = google->rsts[0].rstc;
+
+	return 0;
+}
+
+static int dwc3_google_set_pmu_state(struct dwc3_google *google, int state)
+{
+	u32 reg;
+	int ret;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->host_cfg_offset + HOST_CFG1_OFFSET, &reg);
+
+	reg &= ~HOST_CFG1_PM_POWER_STATE_REQUEST;
+	reg |= (FIELD_PREP(HOST_CFG1_PM_POWER_STATE_REQUEST, state) |
+		HOST_CFG1_PME_EN);
+	regmap_write(google->usb_cfg_regmap,
+		     google->host_cfg_offset + HOST_CFG1_OFFSET, reg);
+
+	ret = regmap_read_poll_timeout(google->usb_cfg_regmap,
+				       google->host_cfg_offset + HC_STATUS_OFFSET, reg,
+				       (FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U2PMU,
+						  reg) == state &&
+					FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U3PMU,
+						  reg) == state),
+				       10, 10000);
+
+	if (ret)
+		dev_err(google->dev, "failed to set PMU state %d\n", state);
+
+	return ret;
+}
+
+/*
+ * Clear pme interrupts and report their status.
+ * The hardware requires write-1 then write-0 sequence to clear the interrupt bits.
+ */
+static u32 dwc3_google_clear_pme_irqs(struct dwc3_google *google)
+{
+	u32 irq_status, reg_set, reg_clear;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->usbint_cfg_offset + USBINT_STATUS_OFFSET, &irq_status);
+
+	irq_status &= (USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW |
+		       USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW);
+	if (!irq_status)
+		return irq_status;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->usbint_cfg_offset + USBINT_CFG1_OFFSET, &reg_set);
+
+	reg_clear = reg_set;
+	if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW) {
+		reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
+		reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
+	}
+	if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW) {
+		reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
+		reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
+	}
+
+	regmap_write(google->usb_cfg_regmap,
+		     google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_set);
+	regmap_write(google->usb_cfg_regmap,
+		     google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_clear);
+
+	return irq_status;
+}
+
+static void dwc3_google_enable_pme_irq(struct dwc3_google *google)
+{
+	u32 reg;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->usbint_cfg_offset + USBINT_CFG1_OFFSET, &reg);
+	reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
+		 USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
+	reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
+		USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
+	regmap_write(google->usb_cfg_regmap,
+		     google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
+
+	enable_irq(google->hs_pme_irq);
+	enable_irq(google->ss_pme_irq);
+	enable_irq_wake(google->hs_pme_irq);
+	enable_irq_wake(google->ss_pme_irq);
+}
+
+static void dwc3_google_disable_pme_irq(struct dwc3_google *google)
+{
+	u32 reg;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->usbint_cfg_offset + USBINT_CFG1_OFFSET, &reg);
+	reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
+		 USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
+	reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
+		USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
+	regmap_write(google->usb_cfg_regmap,
+		     google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
+
+	disable_irq_wake(google->hs_pme_irq);
+	disable_irq_wake(google->ss_pme_irq);
+	disable_irq_nosync(google->hs_pme_irq);
+	disable_irq_nosync(google->ss_pme_irq);
+}
+
+static irqreturn_t dwc3_google_resume_irq(int irq, void *data)
+{
+	struct dwc3_google      *google = data;
+	struct dwc3             *dwc = &google->dwc;
+	u32 irq_status, dr_role;
+
+	irq_status = dwc3_google_clear_pme_irqs(google);
+	dr_role = dwc->current_dr_role;
+
+	if (!irq_status || !google->is_hibernation ||
+	    dr_role != DWC3_GCTL_PRTCAP_HOST) {
+		dev_dbg(google->dev, "spurious pme irq %d, hibernation %d, dr_role %u\n",
+			irq, google->is_hibernation, dr_role);
+		return IRQ_HANDLED;
+	}
+
+	if (dwc->xhci)
+		pm_runtime_resume(&dwc->xhci->dev);
+
+	return IRQ_HANDLED;
+}
+
+static int dwc3_google_request_irq(struct dwc3_google *google, struct platform_device *pdev,
+				   const char *irq_name, const char *req_name)
+{
+	int ret;
+	int irq;
+
+	irq = platform_get_irq_byname(pdev, irq_name);
+	if (irq < 0) {
+		dev_err(google->dev, "invalid irq name %s\n", irq_name);
+		return irq;
+	}
+
+	irq_set_status_flags(irq, IRQ_NOAUTOEN);
+	ret = devm_request_threaded_irq(google->dev, irq, NULL,
+					dwc3_google_resume_irq,
+					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+					req_name, google);
+	if (ret < 0) {
+		dev_err(google->dev, "failed to request irq %s\n", req_name);
+		return ret;
+	}
+
+	return irq;
+}
+
+static int dwc3_google_usb_psw_pd_notifier(struct notifier_block *nb, unsigned long action, void *d)
+{
+	struct dwc3_google *google = container_of(nb, struct dwc3_google, usb_psw_pd_nb);
+	int ret;
+
+	if (!google->is_hibernation)
+		return NOTIFY_OK;
+
+	if (action == GENPD_NOTIFY_OFF) {
+		dev_dbg(google->dev, "enter D3 power state\n");
+		dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D3);
+		ret = reset_control_assert(google->non_sticky_rst);
+		if (ret)
+			dev_err(google->dev, "non sticky reset assert failed: %d\n", ret);
+	} else if (action == GENPD_NOTIFY_ON) {
+		dev_dbg(google->dev, "enter D0 power state\n");
+		dwc3_google_clear_pme_irqs(google);
+		ret = reset_control_deassert(google->non_sticky_rst);
+		if (ret)
+			dev_err(google->dev, "non sticky reset deassert failed: %d\n", ret);
+		dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D0);
+	}
+
+	return NOTIFY_OK;
+}
+
+static void dwc3_google_pm_domain_deinit(struct dwc3_google *google)
+{
+	if (google->usb_top_pd_dl)
+		device_link_del(google->usb_top_pd_dl);
+
+	if (!IS_ERR_OR_NULL(google->usb_top_pd)) {
+		device_set_wakeup_capable(google->usb_top_pd, false);
+		dev_pm_domain_detach(google->usb_top_pd, true);
+	}
+
+	if (google->usb_psw_pd_dl)
+		device_link_del(google->usb_psw_pd_dl);
+
+	if (!IS_ERR_OR_NULL(google->usb_psw_pd)) {
+		dev_pm_genpd_remove_notifier(google->usb_psw_pd);
+		dev_pm_domain_detach(google->usb_psw_pd, true);
+	}
+}
+
+static int dwc3_google_pm_domain_init(struct dwc3_google *google)
+{
+	int ret;
+
+	/*
+	 * Establish PM RUNTIME link between dwc dev and its power domain usb_psw_pd,
+	 * register notifier block to handle hibernation.
+	 */
+	google->usb_psw_pd = dev_pm_domain_attach_by_name(google->dev, "psw");
+	if (IS_ERR_OR_NULL(google->usb_psw_pd)) {
+		dev_err(google->dev, "failed to get psw pd");
+		ret = google->usb_psw_pd ? PTR_ERR(google->usb_psw_pd) : -ENODATA;
+		return ret;
+	}
+
+	google->usb_psw_pd_nb.notifier_call = dwc3_google_usb_psw_pd_notifier;
+	ret = dev_pm_genpd_add_notifier(google->usb_psw_pd, &google->usb_psw_pd_nb);
+	if (ret) {
+		dev_err(google->dev, "failed to add psw pd notifier");
+		goto err;
+	}
+
+	google->usb_psw_pd_dl = device_link_add(google->dev, google->usb_psw_pd,
+						DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
+						DL_FLAG_RPM_ACTIVE);
+	if (!google->usb_psw_pd_dl) {
+		dev_err(google->usb_psw_pd, "failed to add device link");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	/*
+	 * usb_top_pd is the parent power domain of usb_psw_pd. Keeping usb_top_pd on
+	 * while usb_psw_pd is off places the controller in a power-gated state,
+	 * essential for hibernation. Acquire a handle to usb_top_pd and sets it as
+	 * wakeup-capable to allow the domain to be left on during system suspend.
+	 */
+	google->usb_top_pd = dev_pm_domain_attach_by_name(google->dev, "top");
+	if (IS_ERR_OR_NULL(google->usb_top_pd)) {
+		dev_err(google->dev, "failed to get top pd");
+		ret = google->usb_top_pd ? PTR_ERR(google->usb_top_pd) : -ENODATA;
+		goto err;
+	}
+	device_set_wakeup_capable(google->usb_top_pd, true);
+
+	google->usb_top_pd_dl = device_link_add(google->dev, google->usb_top_pd,
+						DL_FLAG_STATELESS);
+	if (!google->usb_top_pd_dl) {
+		dev_err(google->usb_top_pd, "failed to add device link");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	return 0;
+
+err:
+	dwc3_google_pm_domain_deinit(google);
+
+	return ret;
+}
+
+static void dwc3_google_program_usb2only(struct dwc3_google *google)
+{
+	u32 reg;
+
+	regmap_read(google->usb_cfg_regmap,
+		    google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, &reg);
+	reg |= USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE;
+	regmap_write(google->usb_cfg_regmap,
+		     google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, reg);
+}
+
+static int dwc3_google_probe(struct platform_device *pdev)
+{
+	struct dwc3_probe_data	probe_data = {};
+	struct device		*dev = &pdev->dev;
+	struct dwc3_google	*google;
+	struct resource		*res;
+	int			ret;
+	u32			args[2];
+
+	google = devm_kzalloc(&pdev->dev, sizeof(*google), GFP_KERNEL);
+	if (!google)
+		return -ENOMEM;
+
+	google->dev = &pdev->dev;
+
+	ret = dwc3_google_pm_domain_init(google);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to init pdom\n");
+
+	google->usb_cfg_regmap =
+		syscon_regmap_lookup_by_phandle_args(dev->of_node,
+						     "google,usb-cfg-csr",
+						     ARRAY_SIZE(args), args);
+	if (IS_ERR(google->usb_cfg_regmap)) {
+		return dev_err_probe(dev, PTR_ERR(google->usb_cfg_regmap),
+				     "invalid usb cfg csr\n");
+	}
+
+	google->host_cfg_offset = args[0];
+	google->usbint_cfg_offset = args[1];
+
+	if (device_property_match_string(dev, "phy-names", "usb3-phy") < 0) {
+		google->is_usb2only = true;
+		dwc3_google_program_usb2only(google);
+	}
+
+	ret = devm_clk_bulk_get_all_enabled(dev, &google->clks);
+	if (ret < 0) {
+		ret = dev_err_probe(dev, ret, "failed to get and enable clks\n");
+		goto err_deinit_pdom;
+	}
+	google->num_clks = ret;
+
+	ret = dwc3_google_rst_init(google);
+	if (ret) {
+		ret = dev_err_probe(dev, ret, "failed to get resets\n");
+		goto err_deinit_pdom;
+	}
+
+	ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
+	if (ret) {
+		ret = dev_err_probe(dev, ret, "failed to deassert rsts\n");
+		goto err_deinit_pdom;
+	}
+
+	ret = dwc3_google_request_irq(google, pdev, "hs_pme", "USB HS wakeup");
+	if (ret < 0) {
+		ret = dev_err_probe(dev, ret, "failed to request hs pme irq");
+		goto err_reset_assert;
+	}
+	google->hs_pme_irq = ret;
+
+	ret = dwc3_google_request_irq(google, pdev, "ss_pme", "USB SS wakeup");
+	if (ret < 0) {
+		ret = dev_err_probe(dev, ret, "failed to request ss pme irq");
+		goto err_reset_assert;
+	}
+	google->ss_pme_irq = ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = dev_err_probe(dev, -ENODEV, "invalid memory\n");
+		goto err_reset_assert;
+	}
+
+	device_init_wakeup(dev, true);
+
+	google->dwc.dev = dev;
+	probe_data.dwc = &google->dwc;
+	probe_data.res = res;
+	probe_data.ignore_clocks_and_resets = true;
+	ret = dwc3_core_probe(&probe_data);
+	if (ret)  {
+		ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
+		goto err_reset_assert;
+	}
+
+	return 0;
+
+err_reset_assert:
+	reset_control_bulk_assert(google->num_rsts, google->rsts);
+
+err_deinit_pdom:
+	dwc3_google_pm_domain_deinit(google);
+
+	return ret;
+}
+
+static void dwc3_google_remove(struct platform_device *pdev)
+{
+	struct dwc3 *dwc = platform_get_drvdata(pdev);
+	struct dwc3_google *google = to_dwc3_google(dwc);
+
+	dwc3_core_remove(&google->dwc);
+
+	reset_control_bulk_assert(google->num_rsts, google->rsts);
+
+	dwc3_google_pm_domain_deinit(google);
+}
+
+static int dwc3_google_suspend(struct dwc3_google *google, pm_message_t msg)
+{
+	if (pm_runtime_suspended(google->dev))
+		return 0;
+
+	if (google->dwc.current_dr_role == DWC3_GCTL_PRTCAP_HOST) {
+		/*
+		 * Follow dwc3_suspend_common() guidelines for deciding between
+		 * a full teardown and hibernation.
+		 */
+		if (PMSG_IS_AUTO(msg) || device_may_wakeup(google->dev)) {
+			dev_dbg(google->dev, "enter hibernation");
+			pm_runtime_get_sync(google->usb_top_pd);
+			device_wakeup_enable(google->usb_top_pd);
+			dwc3_google_enable_pme_irq(google);
+			google->is_hibernation = true;
+			return 0;
+		}
+	}
+
+	reset_control_bulk_assert(google->num_rsts, google->rsts);
+	clk_bulk_disable_unprepare(google->num_clks, google->clks);
+
+	return 0;
+}
+
+static int dwc3_google_resume(struct dwc3_google *google, pm_message_t msg)
+{
+	int ret;
+
+	if (google->is_hibernation) {
+		dev_dbg(google->dev, "exit hibernation");
+		dwc3_google_disable_pme_irq(google);
+		device_wakeup_disable(google->usb_top_pd);
+		pm_runtime_put_sync(google->usb_top_pd);
+		google->is_hibernation = false;
+		return 0;
+	}
+
+	if (google->is_usb2only)
+		dwc3_google_program_usb2only(google);
+
+	ret = clk_bulk_prepare_enable(google->num_clks, google->clks);
+	if (ret)
+		return ret;
+
+	ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
+	if (ret) {
+		clk_bulk_disable_unprepare(google->num_clks, google->clks);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dwc3_google_pm_suspend(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+	struct dwc3_google *google = to_dwc3_google(dwc);
+	int ret;
+
+	ret = dwc3_pm_suspend(&google->dwc);
+	if (ret)
+		return ret;
+
+	return dwc3_google_suspend(google, PMSG_SUSPEND);
+}
+
+static int dwc3_google_pm_resume(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+	struct dwc3_google *google = to_dwc3_google(dwc);
+	int ret;
+
+	ret = dwc3_google_resume(google, PMSG_RESUME);
+	if (ret)
+		return ret;
+
+	return dwc3_pm_resume(&google->dwc);
+}
+
+static void dwc3_google_complete(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+
+	dwc3_pm_complete(dwc);
+}
+
+static int dwc3_google_prepare(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+
+	return dwc3_pm_prepare(dwc);
+}
+
+static int dwc3_google_runtime_suspend(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+	struct dwc3_google *google = to_dwc3_google(dwc);
+	int ret;
+
+	ret = dwc3_runtime_suspend(&google->dwc);
+	if (ret)
+		return ret;
+
+	return dwc3_google_suspend(google, PMSG_AUTO_SUSPEND);
+}
+
+static int dwc3_google_runtime_resume(struct device *dev)
+{
+	struct dwc3 *dwc = dev_get_drvdata(dev);
+	struct dwc3_google *google = to_dwc3_google(dwc);
+	int ret;
+
+	ret = dwc3_google_resume(google, PMSG_AUTO_RESUME);
+	if (ret)
+		return ret;
+
+	return dwc3_runtime_resume(&google->dwc);
+}
+
+static int dwc3_google_runtime_idle(struct device *dev)
+{
+	return dwc3_runtime_idle(dev_get_drvdata(dev));
+}
+
+static const struct dev_pm_ops dwc3_google_dev_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(dwc3_google_pm_suspend, dwc3_google_pm_resume)
+	RUNTIME_PM_OPS(dwc3_google_runtime_suspend, dwc3_google_runtime_resume,
+		       dwc3_google_runtime_idle)
+	.complete = pm_sleep_ptr(dwc3_google_complete),
+	.prepare = pm_sleep_ptr(dwc3_google_prepare),
+};
+
+static const struct of_device_id dwc3_google_of_match[] = {
+	{ .compatible = "google,lga-dwc3" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, dwc3_google_of_match);
+
+static struct platform_driver dwc3_google_driver = {
+	.probe		= dwc3_google_probe,
+	.remove		= dwc3_google_remove,
+	.driver		= {
+		.name	= "dwc3-google",
+		.pm	= pm_ptr(&dwc3_google_dev_pm_ops),
+		.of_match_table	= dwc3_google_of_match,
+	},
+};
+
+module_platform_driver(dwc3_google_driver);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare DWC3 Google Glue Driver");

-- 
2.52.0.rc2.455.g230fcf2819-goog

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Peter Griffin]

Hi Roy,

Thanks for your patch. It's great to see Laguna support being added upstream.

On Sat, 22 Nov 2025 at 09:32, Roy Luo <royluo@google.com> wrote:
>
> Add support for the DWC3 USB controller found on Google Tensor G5
> (codename: laguna). The controller features dual-role functionality
> and hibernation.
>
> The primary focus is implementing hibernation support in host mode,
> enabling the controller to enter a low-power state (D3). This is
> particularly relevant during system power state transition and
> runtime power management for power efficiency.
> Highlights:
> - Align suspend callback with dwc3_suspend_common() for deciding
>   between a full teardown and hibernation in host mode.
> - Integration with `psw` (power switchable) and `top` power domains,
>   managing their states and device links to support hibernation.
> - A notifier callback dwc3_google_usb_psw_pd_notifier() for
>   `psw` power domain events to manage controller state
>   transitions to/from D3.
> - Coordination of the `non_sticky` reset during power state
>   transitions, asserting it on D3 entry and deasserting on D0 entry
>   in hibernation scenario.
> - Handling of high-speed and super-speed PME interrupts
>   that are generated by remote wakeup during hibernation.
>
> Co-developed-by: Joy Chakraborty <joychakr@google.com>
> Signed-off-by: Joy Chakraborty <joychakr@google.com>
> Co-developed-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
>  drivers/usb/dwc3/Kconfig       |  13 +
>  drivers/usb/dwc3/Makefile      |   1 +
>  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 642 insertions(+)
>
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
>           the dwc3 child node in the device tree.
>           Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
>
> +config USB_DWC3_GOOGLE
> +       tristate "Google Platform"
> +       depends on COMPILE_TEST
> +       depends on OF && COMMON_CLK && RESET_CONTROLLER
> +       help
> +         Support the DesignWare Core USB3 IP found on Google Tensor
> +         SoCs, starting with the G5 generation. This driver includes

consider adding: (Laguna)

> +         support for hibernation in host mode.
> +         Say 'Y' or 'M' if you have one such device.
> +
> +         To compile this driver as a module, choose M here: the
> +         module will be called dwc3-google.ko.
> +
>  endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 96469e48ff9d189cc8d0b65e65424eae2158bcfe..cf1cd408d938b3ac26d58b9be7fcc5af3ee82660 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -58,3 +58,4 @@ 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
> +obj-$(CONFIG_USB_DWC3_GOOGLE)          += dwc3-google.o
> diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..53e04a5409d8a11eb025b0f5cd351cb1b33281ab
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-google.c
> @@ -0,0 +1,628 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * dwc3-google.c - Google DWC3 Specific Glue Layer
> + *
> + * Copyright (c) 2025, Google LLC
> + * Author: Roy Luo <royluo@google.com>
> + */
> +
> +#include <linux/of.h>
> +#include <linux/bitfield.h>
> +#include <linux/irq.h>
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/pm_domain.h>
> +#include <linux/iopoll.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>

Please sort the headers alphabetically. It helps avoid duplicates and
is easier when adding new headers.

Also can you add this file, and the bindings patch to the Tensor SoC
MAINTAINERS entry, so it's easier to review future patches?

With those nits  addressed:
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>

regards,

Peter.

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Sat, Nov 22, 2025 at 11:58:39AM +0000, Peter Griffin wrote:
> Hi Roy,
> 
> Thanks for your patch. It's great to see Laguna support being added upstream.
> 
> On Sat, 22 Nov 2025 at 09:32, Roy Luo <royluo@google.com> wrote:
> >
> > Add support for the DWC3 USB controller found on Google Tensor G5
> > (codename: laguna). The controller features dual-role functionality
> > and hibernation.
> >
> > The primary focus is implementing hibernation support in host mode,
> > enabling the controller to enter a low-power state (D3). This is
> > particularly relevant during system power state transition and
> > runtime power management for power efficiency.
> > Highlights:
> > - Align suspend callback with dwc3_suspend_common() for deciding
> >   between a full teardown and hibernation in host mode.
> > - Integration with `psw` (power switchable) and `top` power domains,
> >   managing their states and device links to support hibernation.
> > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> >   `psw` power domain events to manage controller state
> >   transitions to/from D3.
> > - Coordination of the `non_sticky` reset during power state
> >   transitions, asserting it on D3 entry and deasserting on D0 entry
> >   in hibernation scenario.
> > - Handling of high-speed and super-speed PME interrupts
> >   that are generated by remote wakeup during hibernation.
> >
> > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Roy Luo <royluo@google.com>
> > ---
> >  drivers/usb/dwc3/Kconfig       |  13 +
> >  drivers/usb/dwc3/Makefile      |   1 +
> >  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 642 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> > --- a/drivers/usb/dwc3/Kconfig
> > +++ b/drivers/usb/dwc3/Kconfig
> > @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
> >           the dwc3 child node in the device tree.
> >           Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> >
> > +config USB_DWC3_GOOGLE
> > +       tristate "Google Platform"
> > +       depends on COMPILE_TEST
> > +       depends on OF && COMMON_CLK && RESET_CONTROLLER
> > +       help
> > +         Support the DesignWare Core USB3 IP found on Google Tensor
> > +         SoCs, starting with the G5 generation. This driver includes
> 
> consider adding: (Laguna)

What is "laguna" and why should it be listed here?

> > +         support for hibernation in host mode.
> > +         Say 'Y' or 'M' if you have one such device.
> > +
> > +         To compile this driver as a module, choose M here: the
> > +         module will be called dwc3-google.ko.
> > +
> >  endif
> > diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> > index 96469e48ff9d189cc8d0b65e65424eae2158bcfe..cf1cd408d938b3ac26d58b9be7fcc5af3ee82660 100644
> > --- a/drivers/usb/dwc3/Makefile
> > +++ b/drivers/usb/dwc3/Makefile
> > @@ -58,3 +58,4 @@ 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
> > +obj-$(CONFIG_USB_DWC3_GOOGLE)          += dwc3-google.o
> > diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..53e04a5409d8a11eb025b0f5cd351cb1b33281ab
> > --- /dev/null
> > +++ b/drivers/usb/dwc3/dwc3-google.c
> > @@ -0,0 +1,628 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * dwc3-google.c - Google DWC3 Specific Glue Layer
> > + *
> > + * Copyright (c) 2025, Google LLC
> > + * Author: Roy Luo <royluo@google.com>
> > + */
> > +
> > +#include <linux/of.h>
> > +#include <linux/bitfield.h>
> > +#include <linux/irq.h>
> > +#include <linux/clk.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/regmap.h>
> > +#include <linux/mfd/syscon.h>
> 
> Please sort the headers alphabetically. It helps avoid duplicates and
> is easier when adding new headers.

There is no such requirement for USB drivers.

thanks,

greg k-h

Re: [PATCH v8 0/2] Add Google Tensor SoC USB controller support

[Greg Kroah-Hartman]

On Sat, Nov 22, 2025 at 09:32:04AM +0000, Roy Luo wrote:
> This series introduces USB controller support for the Google Tensor G5
> SoC (codename: Laguna), a new generation of Google silicon first
> launched with Pixel 10 devices.
> 
> The Tensor G5 represents a significant architectural overhaul compared
> to previous Tensor generations (e.g., gs101), which were based on Samsung
> Exynos IP. Although the G5 still utilizes Synopsys IP for the USB
> components, the custom top-level integration introduces a completely new
> design for clock, reset scheme, register interfaces and programming
> sequence, necessitating new drivers and device tree bindings.
> 
> The USB subsystem on Tensor G5 integrates a Synopsys DWC3 USB 3.1
> DRD-Single Port controller with hibernation support, and a custom PHY
> block comprising Synopsys eUSB2 and USB 3.2/DP combo PHYs. The PHY
> support is sent as a separate patch series.
> 
> Co-developed-by: Joy Chakraborty <joychakr@google.com>
> Signed-off-by: Joy Chakraborty <joychakr@google.com>
> Co-developed-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
> Changes in v8:
> - Add COMPILE_TEST to dependencies for build coverage.

Nope, that didn't work :(

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Sat, Nov 22, 2025 at 09:32:06AM +0000, Roy Luo wrote:
> Add support for the DWC3 USB controller found on Google Tensor G5
> (codename: laguna). The controller features dual-role functionality
> and hibernation.
> 
> The primary focus is implementing hibernation support in host mode,
> enabling the controller to enter a low-power state (D3). This is
> particularly relevant during system power state transition and
> runtime power management for power efficiency.
> Highlights:
> - Align suspend callback with dwc3_suspend_common() for deciding
>   between a full teardown and hibernation in host mode.
> - Integration with `psw` (power switchable) and `top` power domains,
>   managing their states and device links to support hibernation.
> - A notifier callback dwc3_google_usb_psw_pd_notifier() for
>   `psw` power domain events to manage controller state
>   transitions to/from D3.
> - Coordination of the `non_sticky` reset during power state
>   transitions, asserting it on D3 entry and deasserting on D0 entry
>   in hibernation scenario.
> - Handling of high-speed and super-speed PME interrupts
>   that are generated by remote wakeup during hibernation.
> 
> Co-developed-by: Joy Chakraborty <joychakr@google.com>
> Signed-off-by: Joy Chakraborty <joychakr@google.com>
> Co-developed-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
>  drivers/usb/dwc3/Kconfig       |  13 +
>  drivers/usb/dwc3/Makefile      |   1 +
>  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 642 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
>  	  the dwc3 child node in the device tree.
>  	  Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
>  
> +config USB_DWC3_GOOGLE
> +	tristate "Google Platform"
> +	depends on COMPILE_TEST
> +	depends on OF && COMMON_CLK && RESET_CONTROLLER

Shouldn't this be:
	depends on (OF && COMMON_CLK && RESET_CONTROLLER) || COMPILE_TEST

I shouldn't have to enable those options to just get a build test here,
the apis should be properly stubbed out if those options are not
enabled, right?

thanks,

greg k-h

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Peter Griffin]

Hi Greg

On Sat, 22 Nov 2025 at 12:35, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Sat, Nov 22, 2025 at 11:58:39AM +0000, Peter Griffin wrote:
> > Hi Roy,
> >
> > Thanks for your patch. It's great to see Laguna support being added upstream.
> >
> > On Sat, 22 Nov 2025 at 09:32, Roy Luo <royluo@google.com> wrote:
> > >
> > > Add support for the DWC3 USB controller found on Google Tensor G5
> > > (codename: laguna). The controller features dual-role functionality
> > > and hibernation.
> > >
> > > The primary focus is implementing hibernation support in host mode,
> > > enabling the controller to enter a low-power state (D3). This is
> > > particularly relevant during system power state transition and
> > > runtime power management for power efficiency.
> > > Highlights:
> > > - Align suspend callback with dwc3_suspend_common() for deciding
> > >   between a full teardown and hibernation in host mode.
> > > - Integration with `psw` (power switchable) and `top` power domains,
> > >   managing their states and device links to support hibernation.
> > > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> > >   `psw` power domain events to manage controller state
> > >   transitions to/from D3.
> > > - Coordination of the `non_sticky` reset during power state
> > >   transitions, asserting it on D3 entry and deasserting on D0 entry
> > >   in hibernation scenario.
> > > - Handling of high-speed and super-speed PME interrupts
> > >   that are generated by remote wakeup during hibernation.
> > >
> > > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > > Signed-off-by: Roy Luo <royluo@google.com>
> > > ---
> > >  drivers/usb/dwc3/Kconfig       |  13 +
> > >  drivers/usb/dwc3/Makefile      |   1 +
> > >  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 642 insertions(+)
> > >
> > > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > > index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> > > --- a/drivers/usb/dwc3/Kconfig
> > > +++ b/drivers/usb/dwc3/Kconfig
> > > @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
> > >           the dwc3 child node in the device tree.
> > >           Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> > >
> > > +config USB_DWC3_GOOGLE
> > > +       tristate "Google Platform"
> > > +       depends on COMPILE_TEST
> > > +       depends on OF && COMMON_CLK && RESET_CONTROLLER
> > > +       help
> > > +         Support the DesignWare Core USB3 IP found on Google Tensor
> > > +         SoCs, starting with the G5 generation. This driver includes
> >
> > consider adding: (Laguna)
>
> What is "laguna" and why should it be listed here?

Laguna is the codename of the SoC (mentioned in the commit message).
The dt compatibles and proposed dt files all mention Laguna (as
opposed to G5) or its abbreviated form lga  so it could be helpful to
have this mentioned in the help message.

See https://lore.kernel.org/lkml/20251111112158.1.I72a0b72562b85d02fee424fed939fea9049ddda9@changeid/

Peter.

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Sat, Nov 22, 2025 at 7:58 PM Peter Griffin <peter.griffin@linaro.org> wrote:
>
> Hi Roy,
>
> Thanks for your patch. It's great to see Laguna support being added upstream.
>
> On Sat, 22 Nov 2025 at 09:32, Roy Luo <royluo@google.com> wrote:
> >
> > Add support for the DWC3 USB controller found on Google Tensor G5
> > (codename: laguna). The controller features dual-role functionality
> > and hibernation.
> >
> > The primary focus is implementing hibernation support in host mode,
> > enabling the controller to enter a low-power state (D3). This is
> > particularly relevant during system power state transition and
> > runtime power management for power efficiency.
> > Highlights:
> > - Align suspend callback with dwc3_suspend_common() for deciding
> >   between a full teardown and hibernation in host mode.
> > - Integration with `psw` (power switchable) and `top` power domains,
> >   managing their states and device links to support hibernation.
> > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> >   `psw` power domain events to manage controller state
> >   transitions to/from D3.
> > - Coordination of the `non_sticky` reset during power state
> >   transitions, asserting it on D3 entry and deasserting on D0 entry
> >   in hibernation scenario.
> > - Handling of high-speed and super-speed PME interrupts
> >   that are generated by remote wakeup during hibernation.
> >
> > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Roy Luo <royluo@google.com>
> > ---
> >  drivers/usb/dwc3/Kconfig       |  13 +
> >  drivers/usb/dwc3/Makefile      |   1 +
> >  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 642 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> > --- a/drivers/usb/dwc3/Kconfig
> > +++ b/drivers/usb/dwc3/Kconfig
> > @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
> >           the dwc3 child node in the device tree.
> >           Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> >
> > +config USB_DWC3_GOOGLE
> > +       tristate "Google Platform"
> > +       depends on COMPILE_TEST
> > +       depends on OF && COMMON_CLK && RESET_CONTROLLER
> > +       help
> > +         Support the DesignWare Core USB3 IP found on Google Tensor
> > +         SoCs, starting with the G5 generation. This driver includes
>
> consider adding: (Laguna)

Ack, will add it in the next revision.

>
> > +         support for hibernation in host mode.
> > +         Say 'Y' or 'M' if you have one such device.
> > +
> > +         To compile this driver as a module, choose M here: the
> > +         module will be called dwc3-google.ko.
> > +
> >  endif
> > diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> > index 96469e48ff9d189cc8d0b65e65424eae2158bcfe..cf1cd408d938b3ac26d58b9be7fcc5af3ee82660 100644
> > --- a/drivers/usb/dwc3/Makefile
> > +++ b/drivers/usb/dwc3/Makefile
> > @@ -58,3 +58,4 @@ 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
> > +obj-$(CONFIG_USB_DWC3_GOOGLE)          += dwc3-google.o
> > diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..53e04a5409d8a11eb025b0f5cd351cb1b33281ab
> > --- /dev/null
> > +++ b/drivers/usb/dwc3/dwc3-google.c
> > @@ -0,0 +1,628 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * dwc3-google.c - Google DWC3 Specific Glue Layer
> > + *
> > + * Copyright (c) 2025, Google LLC
> > + * Author: Roy Luo <royluo@google.com>
> > + */
> > +
> > +#include <linux/of.h>
> > +#include <linux/bitfield.h>
> > +#include <linux/irq.h>
> > +#include <linux/clk.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/regmap.h>
> > +#include <linux/mfd/syscon.h>
>
> Please sort the headers alphabetically. It helps avoid duplicates and
> is easier when adding new headers.

As Greg pointed out, no such requirement exists for usb drivers, but
if it makes things look nicer, why not?
Will sort the headers alphabetically in the next revision.

>
> Also can you add this file, and the bindings patch to the Tensor SoC
> MAINTAINERS entry, so it's easier to review future patches?

Sure! Will update MAITAINERS in the next revision.
Appreciate the review!

Thanks,
Roy Luo


>
> With those nits  addressed:
> Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
>
> regards,
>
> Peter.

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Sat, Nov 22, 2025 at 8:59 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Sat, Nov 22, 2025 at 09:32:06AM +0000, Roy Luo wrote:
> > Add support for the DWC3 USB controller found on Google Tensor G5
> > (codename: laguna). The controller features dual-role functionality
> > and hibernation.
> >
> > The primary focus is implementing hibernation support in host mode,
> > enabling the controller to enter a low-power state (D3). This is
> > particularly relevant during system power state transition and
> > runtime power management for power efficiency.
> > Highlights:
> > - Align suspend callback with dwc3_suspend_common() for deciding
> >   between a full teardown and hibernation in host mode.
> > - Integration with `psw` (power switchable) and `top` power domains,
> >   managing their states and device links to support hibernation.
> > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> >   `psw` power domain events to manage controller state
> >   transitions to/from D3.
> > - Coordination of the `non_sticky` reset during power state
> >   transitions, asserting it on D3 entry and deasserting on D0 entry
> >   in hibernation scenario.
> > - Handling of high-speed and super-speed PME interrupts
> >   that are generated by remote wakeup during hibernation.
> >
> > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Roy Luo <royluo@google.com>
> > ---
> >  drivers/usb/dwc3/Kconfig       |  13 +
> >  drivers/usb/dwc3/Makefile      |   1 +
> >  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 642 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> > --- a/drivers/usb/dwc3/Kconfig
> > +++ b/drivers/usb/dwc3/Kconfig
> > @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
> >         the dwc3 child node in the device tree.
> >         Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> >
> > +config USB_DWC3_GOOGLE
> > +     tristate "Google Platform"
> > +     depends on COMPILE_TEST
> > +     depends on OF && COMMON_CLK && RESET_CONTROLLER
>
> Shouldn't this be:
>         depends on (OF && COMMON_CLK && RESET_CONTROLLER) || COMPILE_TEST
>
> I shouldn't have to enable those options to just get a build test here,
> the apis should be properly stubbed out if those options are not
> enabled, right?
>
> thanks,
>
> greg k-h

Hi Greg,

I agree with your interpretation of COMPILE_TEST but it doesn't
seem to align with upstream convention. I found the following pattern
in several device driver Kconfig files (including but not limited to usb,
pinctrl and phy).

    depends on COMPILE_TEST || ARCH_XXX
    depends on CONFIG_A && CONFIG_B...

For this patch, the APIs exposed by OF, COMMON_CLK
and RESET_CONTROLLER are properly stubbed out so
I'm all good to go with your suggestion, but I'd like to make
sure this approach is conventional.

I plan to add ARCH_GOOGLE as a dependency in the next
version per [1], so the "depends on" would probably look like
the following per your suggestion:

    depends on (OF && COMMON_CLK && RESET_CONTROLLER && ARCH_GOOGLE)
|| COMPILE_TEST

Please let me know your thoughts.
[1] https://lore.kernel.org/linux-phy/1a53d473-fc13-4ac5-ba52-4701d95e3073@kernel.org/

Thanks,
Roy Luo

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Tue, Dec 02, 2025 at 03:01:13AM -0600, Roy Luo wrote:
> On Sat, Nov 22, 2025 at 8:59 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Sat, Nov 22, 2025 at 09:32:06AM +0000, Roy Luo wrote:
> > > Add support for the DWC3 USB controller found on Google Tensor G5
> > > (codename: laguna). The controller features dual-role functionality
> > > and hibernation.
> > >
> > > The primary focus is implementing hibernation support in host mode,
> > > enabling the controller to enter a low-power state (D3). This is
> > > particularly relevant during system power state transition and
> > > runtime power management for power efficiency.
> > > Highlights:
> > > - Align suspend callback with dwc3_suspend_common() for deciding
> > >   between a full teardown and hibernation in host mode.
> > > - Integration with `psw` (power switchable) and `top` power domains,
> > >   managing their states and device links to support hibernation.
> > > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> > >   `psw` power domain events to manage controller state
> > >   transitions to/from D3.
> > > - Coordination of the `non_sticky` reset during power state
> > >   transitions, asserting it on D3 entry and deasserting on D0 entry
> > >   in hibernation scenario.
> > > - Handling of high-speed and super-speed PME interrupts
> > >   that are generated by remote wakeup during hibernation.
> > >
> > > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > > Signed-off-by: Roy Luo <royluo@google.com>
> > > ---
> > >  drivers/usb/dwc3/Kconfig       |  13 +
> > >  drivers/usb/dwc3/Makefile      |   1 +
> > >  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 642 insertions(+)
> > >
> > > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > > index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
> > > --- a/drivers/usb/dwc3/Kconfig
> > > +++ b/drivers/usb/dwc3/Kconfig
> > > @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
> > >         the dwc3 child node in the device tree.
> > >         Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> > >
> > > +config USB_DWC3_GOOGLE
> > > +     tristate "Google Platform"
> > > +     depends on COMPILE_TEST
> > > +     depends on OF && COMMON_CLK && RESET_CONTROLLER
> >
> > Shouldn't this be:
> >         depends on (OF && COMMON_CLK && RESET_CONTROLLER) || COMPILE_TEST
> >
> > I shouldn't have to enable those options to just get a build test here,
> > the apis should be properly stubbed out if those options are not
> > enabled, right?
> >
> > thanks,
> >
> > greg k-h
> 
> Hi Greg,
> 
> I agree with your interpretation of COMPILE_TEST but it doesn't
> seem to align with upstream convention. I found the following pattern
> in several device driver Kconfig files (including but not limited to usb,
> pinctrl and phy).
> 
>     depends on COMPILE_TEST || ARCH_XXX
>     depends on CONFIG_A && CONFIG_B...
> 
> For this patch, the APIs exposed by OF, COMMON_CLK
> and RESET_CONTROLLER are properly stubbed out so
> I'm all good to go with your suggestion, but I'd like to make
> sure this approach is conventional.

Whatever works for building properly, as-is, what you have in this patch
didn't work for my systems at all.

> I plan to add ARCH_GOOGLE as a dependency in the next
> version per [1], so the "depends on" would probably look like
> the following per your suggestion:

But "Google" is not an arch :(

And really, the whole "only have a sub-arch symbol" is something that
personally, I think is totally wrong and prevents kernel images from
being built for more than one "arch".  As an example, the Android GKI
kernel has to support more than one of these, so what does putting this
behind a symbol that no one will actually use mean anything?  Android
will never be only building a ARCH_GOOGLE kernel.

>     depends on (OF && COMMON_CLK && RESET_CONTROLLER && ARCH_GOOGLE)
> || COMPILE_TEST
> 
> Please let me know your thoughts.
> [1] https://lore.kernel.org/linux-phy/1a53d473-fc13-4ac5-ba52-4701d95e3073@kernel.org/

Again, I hate the ARCH_ stuff, but Krzysztof does seem to like it for
some reason, so I'll defer to others here.  But note, as someone who
helps maintain a "generic" ARM64 kernel, these ARCH_* usages for
different platforms do nothing at all to help anyone out.

thanks,

greg k-h

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Krzysztof Kozlowski]

On 02/12/2025 10:01, Roy Luo wrote:
> On Sat, Nov 22, 2025 at 8:59 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
>>
>> On Sat, Nov 22, 2025 at 09:32:06AM +0000, Roy Luo wrote:
>>> Add support for the DWC3 USB controller found on Google Tensor G5
>>> (codename: laguna). The controller features dual-role functionality
>>> and hibernation.
>>>
>>> The primary focus is implementing hibernation support in host mode,
>>> enabling the controller to enter a low-power state (D3). This is
>>> particularly relevant during system power state transition and
>>> runtime power management for power efficiency.
>>> Highlights:
>>> - Align suspend callback with dwc3_suspend_common() for deciding
>>>   between a full teardown and hibernation in host mode.
>>> - Integration with `psw` (power switchable) and `top` power domains,
>>>   managing their states and device links to support hibernation.
>>> - A notifier callback dwc3_google_usb_psw_pd_notifier() for
>>>   `psw` power domain events to manage controller state
>>>   transitions to/from D3.
>>> - Coordination of the `non_sticky` reset during power state
>>>   transitions, asserting it on D3 entry and deasserting on D0 entry
>>>   in hibernation scenario.
>>> - Handling of high-speed and super-speed PME interrupts
>>>   that are generated by remote wakeup during hibernation.
>>>
>>> Co-developed-by: Joy Chakraborty <joychakr@google.com>
>>> Signed-off-by: Joy Chakraborty <joychakr@google.com>
>>> Co-developed-by: Naveen Kumar <mnkumar@google.com>
>>> Signed-off-by: Naveen Kumar <mnkumar@google.com>
>>> Signed-off-by: Roy Luo <royluo@google.com>
>>> ---
>>>  drivers/usb/dwc3/Kconfig       |  13 +
>>>  drivers/usb/dwc3/Makefile      |   1 +
>>>  drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 642 insertions(+)
>>>
>>> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>>> index 4925d15084f816d3ff92059b476ebcc799b56b51..f58c70dabf108878cbefe0abea88572d9ae81e26 100644
>>> --- a/drivers/usb/dwc3/Kconfig
>>> +++ b/drivers/usb/dwc3/Kconfig
>>> @@ -200,4 +200,17 @@ config USB_DWC3_GENERIC_PLAT
>>>         the dwc3 child node in the device tree.
>>>         Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
>>>
>>> +config USB_DWC3_GOOGLE
>>> +     tristate "Google Platform"
>>> +     depends on COMPILE_TEST
>>> +     depends on OF && COMMON_CLK && RESET_CONTROLLER
>>
>> Shouldn't this be:
>>         depends on (OF && COMMON_CLK && RESET_CONTROLLER) || COMPILE_TEST
>>
>> I shouldn't have to enable those options to just get a build test here,
>> the apis should be properly stubbed out if those options are not
>> enabled, right?
>>
>> thanks,
>>
>> greg k-h
> 
> Hi Greg,
> 
> I agree with your interpretation of COMPILE_TEST but it doesn't
> seem to align with upstream convention. I found the following pattern

The problem is not in Greg's solution but your code:
	depends on COMPILE_TEST

which makes absolutely no sense because it means this cannot be used
anywhere (in reasonable terms).


> in several device driver Kconfig files (including but not limited to usb,
> pinctrl and phy).
> 
>     depends on COMPILE_TEST || ARCH_XXX
>     depends on CONFIG_A && CONFIG_B...
> 
> For this patch, the APIs exposed by OF, COMMON_CLK
> and RESET_CONTROLLER are properly stubbed out so
> I'm all good to go with your suggestion, but I'd like to make
> sure this approach is conventional.
> 
> I plan to add ARCH_GOOGLE as a dependency in the next
> version per [1], so the "depends on" would probably look like
> the following per your suggestion:
> 
>     depends on (OF && COMMON_CLK && RESET_CONTROLLER && ARCH_GOOGLE)
> || COMPILE_TEST
> 


No, instead depends ARCH_foo || COMPILE_TEST

and drop all other dependencies. You don't need them.


Best regards,
Krzysztof

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Krzysztof Kozlowski]

On 02/12/2025 10:27, Greg Kroah-Hartman wrote:
>>>         depends on (OF && COMMON_CLK && RESET_CONTROLLER) || COMPILE_TEST
>>>
>>> I shouldn't have to enable those options to just get a build test here,
>>> the apis should be properly stubbed out if those options are not
>>> enabled, right?
>>>
>>> thanks,
>>>
>>> greg k-h
>>
>> Hi Greg,
>>
>> I agree with your interpretation of COMPILE_TEST but it doesn't
>> seem to align with upstream convention. I found the following pattern
>> in several device driver Kconfig files (including but not limited to usb,
>> pinctrl and phy).
>>
>>     depends on COMPILE_TEST || ARCH_XXX
>>     depends on CONFIG_A && CONFIG_B...
>>
>> For this patch, the APIs exposed by OF, COMMON_CLK
>> and RESET_CONTROLLER are properly stubbed out so
>> I'm all good to go with your suggestion, but I'd like to make
>> sure this approach is conventional.
> 
> Whatever works for building properly, as-is, what you have in this patch
> didn't work for my systems at all.
> 
>> I plan to add ARCH_GOOGLE as a dependency in the next
>> version per [1], so the "depends on" would probably look like
>> the following per your suggestion:
> 
> But "Google" is not an arch :(
> 
> And really, the whole "only have a sub-arch symbol" is something that
> personally, I think is totally wrong and prevents kernel images from
> being built for more than one "arch".  As an example, the Android GKI

Probably you think ARCH_FOO as arch/FOO/ directory, but this is not the
case. ARCH_FOO in this context is SoC platform, so e.g.
arch/arm64/boot/dts/FOO/.

All of ARCH_FOO build into one image and that's recommended way to limit
unnecessary drivers.

It's just confusing naming for whatever reason.

> kernel has to support more than one of these, so what does putting this
> behind a symbol that no one will actually use mean anything?  Android
> will never be only building a ARCH_GOOGLE kernel.

But distros will be, people will be. OK, maybe not for ARCH_GOOGLE, but
ARCH_QCOM we do for Qualcomm-based laptops and embedded folks even more.

We had this talk in the past. The point is that these drivers here are
unusable outside of that hardware platform, so only when you choose
hardware platform (ARCH_EXYNOS, ARCH_GOOGLE, ARCH_QCOM) you will be able
to choose these drivers.

You can also look at ARCH_FOO a bit orthogonal to actual kernel
architecture, because ARCH_EXYNOS is for both arm (arm32) and arm64. The
drivers should be available for all Exynos-platforms, regardless whether
this is arm32 or arm64.

> 
>>     depends on (OF && COMMON_CLK && RESET_CONTROLLER && ARCH_GOOGLE)
>> || COMPILE_TEST
>>
>> Please let me know your thoughts.
>> [1] https://lore.kernel.org/linux-phy/1a53d473-fc13-4ac5-ba52-4701d95e3073@kernel.org/
> 
> Again, I hate the ARCH_ stuff, but Krzysztof does seem to like it for
> some reason, so I'll defer to others here.  But note, as someone who
> helps maintain a "generic" ARM64 kernel, these ARCH_* usages for
> different platforms do nothing at all to help anyone out.

True and that's not their goal. The truly generic kernels, like you
mentioned or arch/arm64/configs/defconfig, build everything for arm64.
The entire point is to limit this for actual users wanting much smaller
kernels and distros, which do not need these on for example RISC-V.


Best regards,
Krzysztof

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Doug Anderson]

Hi,

On Tue, Dec 2, 2025 at 1:42 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> >> I plan to add ARCH_GOOGLE as a dependency in the next
> >> version per [1], so the "depends on" would probably look like
> >> the following per your suggestion:
> >
> > But "Google" is not an arch :(
> >
> > And really, the whole "only have a sub-arch symbol" is something that
> > personally, I think is totally wrong and prevents kernel images from
> > being built for more than one "arch".  As an example, the Android GKI
>
> Probably you think ARCH_FOO as arch/FOO/ directory, but this is not the
> case. ARCH_FOO in this context is SoC platform, so e.g.
> arch/arm64/boot/dts/FOO/.
>
> All of ARCH_FOO build into one image and that's recommended way to limit
> unnecessary drivers.
>
> It's just confusing naming for whatever reason.
>
> > kernel has to support more than one of these, so what does putting this
> > behind a symbol that no one will actually use mean anything?  Android
> > will never be only building a ARCH_GOOGLE kernel.
>
> But distros will be, people will be. OK, maybe not for ARCH_GOOGLE, but
> ARCH_QCOM we do for Qualcomm-based laptops and embedded folks even more.
>
> We had this talk in the past. The point is that these drivers here are
> unusable outside of that hardware platform, so only when you choose
> hardware platform (ARCH_EXYNOS, ARCH_GOOGLE, ARCH_QCOM) you will be able
> to choose these drivers.
>
> You can also look at ARCH_FOO a bit orthogonal to actual kernel
> architecture, because ARCH_EXYNOS is for both arm (arm32) and arm64. The
> drivers should be available for all Exynos-platforms, regardless whether
> this is arm32 or arm64.

FWIW I don't feel strongly about the ARCH_XYZ Kconfig settings, but
I'd tend to agree with Krzysztof that I personally find them useful.
Sure, it's fine to just turn all of the ARCH_XYZ values on and they
shouldn't conflict with each other, but it provides an easy way for
someone to know that certain drivers are only useful if the kernel
you're building supports a given arch. If I'm building a kernel that
doesn't need to support any Qualcomm boards, for instance, I can just
turn that arch off and I don't even need to think about all of the
Qualcomm-related config options.

FWIW, if you do add a "depend" on ARCH_GOOGLE you should mention
somewhere (maybe "after the cut" in your patch) that ARCH_GOOGLE
doesn't exist yet. It should eventually exist when some version of
this patch lands:

https://lore.kernel.org/r/20251111112158.3.I35b9e835ac49ab408e5ca3e0983930a1f1395814@changeid/

...but it's not there yet. ;-)

-Doug

Re: [PATCH v8 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Wed, Dec 3, 2025 at 12:25 AM Doug Anderson <dianders@google.com> wrote:
>
> Hi,
>
> On Tue, Dec 2, 2025 at 1:42 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> >
> > >> I plan to add ARCH_GOOGLE as a dependency in the next
> > >> version per [1], so the "depends on" would probably look like
> > >> the following per your suggestion:
> > >
> > > But "Google" is not an arch :(
> > >
> > > And really, the whole "only have a sub-arch symbol" is something that
> > > personally, I think is totally wrong and prevents kernel images from
> > > being built for more than one "arch".  As an example, the Android GKI
> >
> > Probably you think ARCH_FOO as arch/FOO/ directory, but this is not the
> > case. ARCH_FOO in this context is SoC platform, so e.g.
> > arch/arm64/boot/dts/FOO/.
> >
> > All of ARCH_FOO build into one image and that's recommended way to limit
> > unnecessary drivers.
> >
> > It's just confusing naming for whatever reason.
> >
> > > kernel has to support more than one of these, so what does putting this
> > > behind a symbol that no one will actually use mean anything?  Android
> > > will never be only building a ARCH_GOOGLE kernel.
> >
> > But distros will be, people will be. OK, maybe not for ARCH_GOOGLE, but
> > ARCH_QCOM we do for Qualcomm-based laptops and embedded folks even more.
> >
> > We had this talk in the past. The point is that these drivers here are
> > unusable outside of that hardware platform, so only when you choose
> > hardware platform (ARCH_EXYNOS, ARCH_GOOGLE, ARCH_QCOM) you will be able
> > to choose these drivers.
> >
> > You can also look at ARCH_FOO a bit orthogonal to actual kernel
> > architecture, because ARCH_EXYNOS is for both arm (arm32) and arm64. The
> > drivers should be available for all Exynos-platforms, regardless whether
> > this is arm32 or arm64.
>
> FWIW I don't feel strongly about the ARCH_XYZ Kconfig settings, but
> I'd tend to agree with Krzysztof that I personally find them useful.
> Sure, it's fine to just turn all of the ARCH_XYZ values on and they
> shouldn't conflict with each other, but it provides an easy way for
> someone to know that certain drivers are only useful if the kernel
> you're building supports a given arch. If I'm building a kernel that
> doesn't need to support any Qualcomm boards, for instance, I can just
> turn that arch off and I don't even need to think about all of the
> Qualcomm-related config options.
>
> FWIW, if you do add a "depend" on ARCH_GOOGLE you should mention
> somewhere (maybe "after the cut" in your patch) that ARCH_GOOGLE
> doesn't exist yet. It should eventually exist when some version of
> this patch lands:
>
> https://lore.kernel.org/r/20251111112158.3.I35b9e835ac49ab408e5ca3e0983930a1f1395814@changeid/
>
> ...but it's not there yet. ;-)
>
> -Doug

Hi all,

I appreciate the detailed discussion regarding Kconfig dependencies.
Based on all the feedback, I'll make the following adjustments:
- I will update the Kconfig dependency to depends on
  ARCH_GOOGLE || COMPILE_TEST and drop the other
  dependencies on OF && COMMON_CLK && RESET_CONTROLLER
  as suggested by Krzysztof. This should also address the build
  coverage concern from Greg.
- As Doug pointed out, the ARCH_GOOGLE Kconfig option does
  not exist... yet. I will add a note about this in the next version.

Thank you all again for helping me improve this patch.
I will send out a new version with these changes soon.

Regards,
Roy Luo