[PATCH v9 0/2] Add Google Tensor SoC USB controller support

[PATCH v9 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 v9:
- Update the Kconfig dependency to depends on ARCH_GOOGLE || COMPILE_TEST
  Note that ARCH_GOOGLE does not exist yet but will eventually
  be there when the following patch lands
  https://lore.kernel.org/r/20251111112158.3.I35b9e835ac49ab408e5ca3e0983930a1f1395814@changeid/
- Mention SoC codename Laguna in Kconfig description.
- Sort the header alphabetically.
- Add driver and binding files to the Tensor SoC MAINTAINER entry.
Link to v8: https://lore.kernel.org/r/20251122-controller-v8-0-e7562e0df658@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 +++++
 MAINTAINERS                                        |   2 +
 drivers/usb/dwc3/Kconfig                           |  12 +
 drivers/usb/dwc3/Makefile                          |   1 +
 drivers/usb/dwc3/dwc3-google.c                     | 628 +++++++++++++++++++++
 5 files changed, 783 insertions(+)
---
base-commit: 43dfc13ca972988e620a6edb72956981b75ab6b0
change-id: 20251122-controller-129b0dd57a74

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

[PATCH v9 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.

Signed-off-by: Roy Luo <royluo@google.com>
---
 .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
 MAINTAINERS                                        |   1 +
 2 files changed, 141 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>;
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 772af0072fff0921000c6fe27c018666c1579e48..61f5768b31ae31cd72f4c2a3b74398f9473e192b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10662,6 +10662,7 @@ P:	Documentation/process/maintainer-soc-clean-dts.rst
 C:	irc://irc.oftc.net/pixel6-kernel-dev
 F:	Documentation/devicetree/bindings/clock/google,gs101-clock.yaml
 F:	Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
+F:	Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
 F:	arch/arm64/boot/dts/exynos/google/
 F:	drivers/clk/samsung/clk-gs101.c
 F:	drivers/phy/samsung/phy-gs101-ufs.c

-- 
2.52.0.223.gf5cc29aaa4-goog

[PATCH v9 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>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Roy Luo <royluo@google.com>
---
 MAINTAINERS                    |   1 +
 drivers/usb/dwc3/Kconfig       |  12 +
 drivers/usb/dwc3/Makefile      |   1 +
 drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 642 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 61f5768b31ae31cd72f4c2a3b74398f9473e192b..0659847b980128801b63014de96294c07abca3a0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10666,6 +10666,7 @@ F:	Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
 F:	arch/arm64/boot/dts/exynos/google/
 F:	drivers/clk/samsung/clk-gs101.c
 F:	drivers/phy/samsung/phy-gs101-ufs.c
+F:	drivers/usb/dwc3/dwc3-google.c
 F:	include/dt-bindings/clock/google,gs101.h
 K:	[gG]oogle.?[tT]ensor
 
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 4925d15084f816d3ff92059b476ebcc799b56b51..05e4b7e1d98b1c03c8887c50dfff7e39d365f2a3 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -200,4 +200,16 @@ 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 ARCH_GOOGLE || COMPILE_TEST
+	help
+	  Support the DesignWare Core USB3 IP found on Google Tensor SoCs,
+	  starting with the G5 generation (Laguna). 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..a19857bd6b131d841d165717b70f2959b4bac806
--- /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/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/reset.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");

-- 
2.52.0.223.gf5cc29aaa4-goog

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> +config USB_DWC3_GOOGLE
> +	tristate "Google Platform"
> +	depends on ARCH_GOOGLE || COMPILE_TEST

There is no ARCH_GOOGLE in the tree now, so how is this supposed to
work?  Shouldn't tools that check for "invalid config options" trigger
on this?

thanks,

greg k-h

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > +config USB_DWC3_GOOGLE
> > +     tristate "Google Platform"
> > +     depends on ARCH_GOOGLE || COMPILE_TEST
>
> There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> work?  Shouldn't tools that check for "invalid config options" trigger
> on this?
>
> thanks,
>
> greg k-h

Hi Greg,

The menuconfig looks like the following and it doesn't complain:
| Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
| Type  : unknown
|
| Symbol: PHY_GOOGLE_USB [=y]
| Type  : tristate
| Defined at drivers/phy/Kconfig:104
|     Prompt: Google Tensor SoC USB PHY driver
|     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]

According to Kconfig documentation [1], the unknown symbol
would simply be evaluated as an "n", which is what we want.
"Convert the symbol into an expression. Boolean and tristate
symbols are simply converted into the respective expression
values. All other symbol types result in ‘n’."

In a different Kconfig documentation, an environment variable
"KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
undefined symbols in the "config input", but I can't find one that
catches undefined symbols in the Kconfig tree itself.

That is, the tool seems to allow this.
However, if this turns out to be a major problem. I think we
can either:
- Remove ARCH_GOOGLE and leave COMPILE_TEST as
  the only dependency. Then add ARCH_GOOGLE back
  later once it's in the tree.
- Defer the whole patch series until ARCH_GOOGLE is
  present (I hope not).

[1] https://docs.kernel.org/kbuild/kconfig-language.html#menu-dependencies
[2] https://www.kernel.org/doc/Documentation/kbuild/kconfig.rst

Regards,
Roy Luo

Re: [PATCH v9 1/2] dt-bindings: usb: dwc3: Add Google Tensor G5 DWC3

[Krzysztof Kozlowski]

On 05/12/2025 03:26, Roy Luo wrote:
> 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.
> 
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
>  .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
>  MAINTAINERS                                        |   1 +
>  2 files changed, 141 insertions(+)
> 

Nothing explains reason to ignore review. I am not doing same work
twice, please respect maintainers' time.

<form letter>
This is a friendly reminder during the review process.

It looks like you received a tag and forgot to add it.

If you do not know the process, here is a short explanation:
Please add Acked-by/Reviewed-by/Tested-by tags when posting new versions
of patchset, under or above your Signed-off-by tag, unless patch changed
significantly (e.g. new properties added to the DT bindings). Tag is
"received", when provided in a message replied to you on the mailing
list. Tools like b4 can help here. However, there's no need to repost
patches *only* to add the tags. The upstream maintainer will do that for
tags received on the version they apply.

Please read:
https://elixir.bootlin.com/linux/v6.12-rc3/source/Documentation/process/submitting-patches.rst#L577

If a tag was not added on purpose, please state why and what changed.
</form letter>

Best regards,
Krzysztof

Re: [PATCH v9 1/2] dt-bindings: usb: dwc3: Add Google Tensor G5 DWC3

[Krzysztof Kozlowski]

On Fri, Dec 05, 2025 at 02:26:37AM +0000, Roy Luo wrote:
> 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.
> 
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
>  .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
>  MAINTAINERS                                        |   1 +
>  2 files changed, 141 insertions(+)

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Thinh Nguyen]

On Thu, Dec 04, 2025, Roy Luo wrote:
> On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > +config USB_DWC3_GOOGLE
> > > +     tristate "Google Platform"
> > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> >
> > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > work?  Shouldn't tools that check for "invalid config options" trigger
> > on this?
> >
> > thanks,
> >
> > greg k-h
> 
> Hi Greg,
> 
> The menuconfig looks like the following and it doesn't complain:
> | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> | Type  : unknown
> |
> | Symbol: PHY_GOOGLE_USB [=y]
> | Type  : tristate
> | Defined at drivers/phy/Kconfig:104
> |     Prompt: Google Tensor SoC USB PHY driver
> |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> 
> According to Kconfig documentation [1], the unknown symbol
> would simply be evaluated as an "n", which is what we want.
> "Convert the symbol into an expression. Boolean and tristate
> symbols are simply converted into the respective expression
> values. All other symbol types result in ‘n’."
> 
> In a different Kconfig documentation, an environment variable
> "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> undefined symbols in the "config input", but I can't find one that
> catches undefined symbols in the Kconfig tree itself.
> 
> That is, the tool seems to allow this.
> However, if this turns out to be a major problem. I think we
> can either:
> - Remove ARCH_GOOGLE and leave COMPILE_TEST as
>   the only dependency. Then add ARCH_GOOGLE back
>   later once it's in the tree.
> - Defer the whole patch series until ARCH_GOOGLE is
>   present (I hope not).
> 
> [1] https://urldefense.com/v3/__https://docs.kernel.org/kbuild/kconfig-language.html*menu-dependencies__;Iw!!A4F2R9G_pg!e-y2_BsSNhXF1v5K6tBJX-OabgKJM9WVdvwyKoB6tg9ooCLVg8WiQ4UrStOF2YZQ_Zs6tC6HVh7wCpqkEfU$ 
> [2] https://urldefense.com/v3/__https://www.kernel.org/doc/Documentation/kbuild/kconfig.rst__;!!A4F2R9G_pg!e-y2_BsSNhXF1v5K6tBJX-OabgKJM9WVdvwyKoB6tg9ooCLVg8WiQ4UrStOF2YZQ_Zs6tC6HVh7wHpoUlhY$ 
> 

Hi Greg, Roy,

Just checking, are we aligned here?

BR,
Thinh

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Tue, Dec 16, 2025 at 3:34 PM Thinh Nguyen <Thinh.Nguyen@synopsys.com> wrote:
>
> On Thu, Dec 04, 2025, Roy Luo wrote:
> > On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > > +config USB_DWC3_GOOGLE
> > > > +     tristate "Google Platform"
> > > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> > >
> > > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > > work?  Shouldn't tools that check for "invalid config options" trigger
> > > on this?
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > Hi Greg,
> >
> > The menuconfig looks like the following and it doesn't complain:
> > | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> > | Type  : unknown
> > |
> > | Symbol: PHY_GOOGLE_USB [=y]
> > | Type  : tristate
> > | Defined at drivers/phy/Kconfig:104
> > |     Prompt: Google Tensor SoC USB PHY driver
> > |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> >
> > According to Kconfig documentation [1], the unknown symbol
> > would simply be evaluated as an "n", which is what we want.
> > "Convert the symbol into an expression. Boolean and tristate
> > symbols are simply converted into the respective expression
> > values. All other symbol types result in ‘n’."
> >
> > In a different Kconfig documentation, an environment variable
> > "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> > undefined symbols in the "config input", but I can't find one that
> > catches undefined symbols in the Kconfig tree itself.
> >
> > That is, the tool seems to allow this.
> > However, if this turns out to be a major problem. I think we
> > can either:
> > - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> >   the only dependency. Then add ARCH_GOOGLE back
> >   later once it's in the tree.
> > - Defer the whole patch series until ARCH_GOOGLE is
> >   present (I hope not).
> >
> > [1] https://urldefense.com/v3/__https://docs.kernel.org/kbuild/kconfig-language.html*menu-dependencies__;Iw!!A4F2R9G_pg!e-y2_BsSNhXF1v5K6tBJX-OabgKJM9WVdvwyKoB6tg9ooCLVg8WiQ4UrStOF2YZQ_Zs6tC6HVh7wCpqkEfU$
> > [2] https://urldefense.com/v3/__https://www.kernel.org/doc/Documentation/kbuild/kconfig.rst__;!!A4F2R9G_pg!e-y2_BsSNhXF1v5K6tBJX-OabgKJM9WVdvwyKoB6tg9ooCLVg8WiQ4UrStOF2YZQ_Zs6tC6HVh7wHpoUlhY$
> >
>
> Hi Greg, Roy,
>
> Just checking, are we aligned here?
>
> BR,
> Thinh

Thinh,

Thanks for checking in. I'm still waiting on Greg's reply
regarding the Kconfig question.

BTW, I silently dropped your Ack-by tag in v8 due to the
changes in Kconfig and MAINTAINERS files, which I
should've noted in the changelog but I didn't. Sorry for
the inconvenience. Could you please review the current
version again and provide your tag if it looks good?

Regards,
Roy

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > +config USB_DWC3_GOOGLE
> > > +     tristate "Google Platform"
> > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> >
> > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > work?  Shouldn't tools that check for "invalid config options" trigger
> > on this?
> >
> > thanks,
> >
> > greg k-h
> 
> Hi Greg,
> 
> The menuconfig looks like the following and it doesn't complain:
> | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> | Type  : unknown
> |
> | Symbol: PHY_GOOGLE_USB [=y]
> | Type  : tristate
> | Defined at drivers/phy/Kconfig:104
> |     Prompt: Google Tensor SoC USB PHY driver
> |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> 
> According to Kconfig documentation [1], the unknown symbol
> would simply be evaluated as an "n", which is what we want.
> "Convert the symbol into an expression. Boolean and tristate
> symbols are simply converted into the respective expression
> values. All other symbol types result in ‘n’."
> 
> In a different Kconfig documentation, an environment variable
> "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> undefined symbols in the "config input", but I can't find one that
> catches undefined symbols in the Kconfig tree itself.
> 
> That is, the tool seems to allow this.
> However, if this turns out to be a major problem. I think we
> can either:
> - Remove ARCH_GOOGLE and leave COMPILE_TEST as
>   the only dependency. Then add ARCH_GOOGLE back
>   later once it's in the tree.

Please do this.  I do not want to take patches that purposfully add
dependencies on config options that might, or might not, appear in the
future.  Please just remove all of the dependancies for now, as they are
not needed, right?

thanks,

greg k-h

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> > On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > > +config USB_DWC3_GOOGLE
> > > > +     tristate "Google Platform"
> > > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> > >
> > > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > > work?  Shouldn't tools that check for "invalid config options" trigger
> > > on this?
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > Hi Greg,
> >
> > The menuconfig looks like the following and it doesn't complain:
> > | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> > | Type  : unknown
> > |
> > | Symbol: PHY_GOOGLE_USB [=y]
> > | Type  : tristate
> > | Defined at drivers/phy/Kconfig:104
> > |     Prompt: Google Tensor SoC USB PHY driver
> > |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> >
> > According to Kconfig documentation [1], the unknown symbol
> > would simply be evaluated as an "n", which is what we want.
> > "Convert the symbol into an expression. Boolean and tristate
> > symbols are simply converted into the respective expression
> > values. All other symbol types result in ‘n’."
> >
> > In a different Kconfig documentation, an environment variable
> > "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> > undefined symbols in the "config input", but I can't find one that
> > catches undefined symbols in the Kconfig tree itself.
> >
> > That is, the tool seems to allow this.
> > However, if this turns out to be a major problem. I think we
> > can either:
> > - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> >   the only dependency. Then add ARCH_GOOGLE back
> >   later once it's in the tree.
>
> Please do this.  I do not want to take patches that purposfully add
> dependencies on config options that might, or might not, appear in the
> future.  Please just remove all of the dependancies for now, as they are
> not needed, right?
>
> thanks,
>
> greg k-h

Greg,

Yes, we can remove ARCH_GOOGLE for now.
To clarify, we're not removing all of the dependencies, we still want
to keep COMPILE_TEST for build tests, right?
Please let me know if you think otherwise.

Thanks,
Roy

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Doug Anderson]

Hi,

On Wed, Dec 17, 2025 at 11:18 AM Roy Luo <royluo@google.com> wrote:
>
> On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> > > On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> > > <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > > > +config USB_DWC3_GOOGLE
> > > > > +     tristate "Google Platform"
> > > > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> > > >
> > > > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > > > work?  Shouldn't tools that check for "invalid config options" trigger
> > > > on this?
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > >
> > > Hi Greg,
> > >
> > > The menuconfig looks like the following and it doesn't complain:
> > > | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> > > | Type  : unknown
> > > |
> > > | Symbol: PHY_GOOGLE_USB [=y]
> > > | Type  : tristate
> > > | Defined at drivers/phy/Kconfig:104
> > > |     Prompt: Google Tensor SoC USB PHY driver
> > > |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> > >
> > > According to Kconfig documentation [1], the unknown symbol
> > > would simply be evaluated as an "n", which is what we want.
> > > "Convert the symbol into an expression. Boolean and tristate
> > > symbols are simply converted into the respective expression
> > > values. All other symbol types result in ‘n’."
> > >
> > > In a different Kconfig documentation, an environment variable
> > > "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> > > undefined symbols in the "config input", but I can't find one that
> > > catches undefined symbols in the Kconfig tree itself.
> > >
> > > That is, the tool seems to allow this.
> > > However, if this turns out to be a major problem. I think we
> > > can either:
> > > - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> > >   the only dependency. Then add ARCH_GOOGLE back
> > >   later once it's in the tree.
> >
> > Please do this.  I do not want to take patches that purposfully add
> > dependencies on config options that might, or might not, appear in the
> > future.  Please just remove all of the dependancies for now, as they are
> > not needed, right?
> >
> > thanks,
> >
> > greg k-h
>
> Greg,
>
> Yes, we can remove ARCH_GOOGLE for now.
> To clarify, we're not removing all of the dependencies, we still want
> to keep COMPILE_TEST for build tests, right?
> Please let me know if you think otherwise.

I think you'd just remove all of them. Normally COMPILE_TEST just
allows folks to compile stuff even when they don't want the ARCH. We
can can add ARCH_GOOGLE back in later once the config exists.

-Doug

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Wed, Dec 17, 2025 at 12:14 PM Doug Anderson <dianders@google.com> wrote:
>
> Hi,
>
> On Wed, Dec 17, 2025 at 11:18 AM Roy Luo <royluo@google.com> wrote:
> >
> > On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> > > > On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> > > > <gregkh@linuxfoundation.org> wrote:
> > > > >
> > > > > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > > > > +config USB_DWC3_GOOGLE
> > > > > > +     tristate "Google Platform"
> > > > > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> > > > >
> > > > > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > > > > work?  Shouldn't tools that check for "invalid config options" trigger
> > > > > on this?
> > > > >
> > > > > thanks,
> > > > >
> > > > > greg k-h
> > > >
> > > > Hi Greg,
> > > >
> > > > The menuconfig looks like the following and it doesn't complain:
> > > > | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> > > > | Type  : unknown
> > > > |
> > > > | Symbol: PHY_GOOGLE_USB [=y]
> > > > | Type  : tristate
> > > > | Defined at drivers/phy/Kconfig:104
> > > > |     Prompt: Google Tensor SoC USB PHY driver
> > > > |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> > > >
> > > > According to Kconfig documentation [1], the unknown symbol
> > > > would simply be evaluated as an "n", which is what we want.
> > > > "Convert the symbol into an expression. Boolean and tristate
> > > > symbols are simply converted into the respective expression
> > > > values. All other symbol types result in ‘n’."
> > > >
> > > > In a different Kconfig documentation, an environment variable
> > > > "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> > > > undefined symbols in the "config input", but I can't find one that
> > > > catches undefined symbols in the Kconfig tree itself.
> > > >
> > > > That is, the tool seems to allow this.
> > > > However, if this turns out to be a major problem. I think we
> > > > can either:
> > > > - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> > > >   the only dependency. Then add ARCH_GOOGLE back
> > > >   later once it's in the tree.
> > >
> > > Please do this.  I do not want to take patches that purposfully add
> > > dependencies on config options that might, or might not, appear in the
> > > future.  Please just remove all of the dependancies for now, as they are
> > > not needed, right?
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > Greg,
> >
> > Yes, we can remove ARCH_GOOGLE for now.
> > To clarify, we're not removing all of the dependencies, we still want
> > to keep COMPILE_TEST for build tests, right?
> > Please let me know if you think otherwise.
>
> I think you'd just remove all of them. Normally COMPILE_TEST just
> allows folks to compile stuff even when they don't want the ARCH. We
> can can add ARCH_GOOGLE back in later once the config exists.
>
> -Doug

Doug,

Thanks for chiming in. I'm hesitant to remove COMPILE_TEST
because Greg specifically requested its inclusion in v7 [1].
Also it seems beneficial to get some build coverage before
ARCH_GOOGLE is officially added to the tree.
Greg, could you clarify?

[1] https://lore.kernel.org/linux-usb/2025112144-claw-recolor-49c3@gregkh/

Thanks,
Roy

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Greg Kroah-Hartman]

On Wed, Dec 17, 2025 at 05:34:37PM -0800, Roy Luo wrote:
> On Wed, Dec 17, 2025 at 12:14 PM Doug Anderson <dianders@google.com> wrote:
> >
> > Hi,
> >
> > On Wed, Dec 17, 2025 at 11:18 AM Roy Luo <royluo@google.com> wrote:
> > >
> > > On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
> > > <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> > > > > On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> > > > > <gregkh@linuxfoundation.org> wrote:
> > > > > >
> > > > > > On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> > > > > > > +config USB_DWC3_GOOGLE
> > > > > > > +     tristate "Google Platform"
> > > > > > > +     depends on ARCH_GOOGLE || COMPILE_TEST
> > > > > >
> > > > > > There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> > > > > > work?  Shouldn't tools that check for "invalid config options" trigger
> > > > > > on this?
> > > > > >
> > > > > > thanks,
> > > > > >
> > > > > > greg k-h
> > > > >
> > > > > Hi Greg,
> > > > >
> > > > > The menuconfig looks like the following and it doesn't complain:
> > > > > | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> > > > > | Type  : unknown
> > > > > |
> > > > > | Symbol: PHY_GOOGLE_USB [=y]
> > > > > | Type  : tristate
> > > > > | Defined at drivers/phy/Kconfig:104
> > > > > |     Prompt: Google Tensor SoC USB PHY driver
> > > > > |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> > > > >
> > > > > According to Kconfig documentation [1], the unknown symbol
> > > > > would simply be evaluated as an "n", which is what we want.
> > > > > "Convert the symbol into an expression. Boolean and tristate
> > > > > symbols are simply converted into the respective expression
> > > > > values. All other symbol types result in ‘n’."
> > > > >
> > > > > In a different Kconfig documentation, an environment variable
> > > > > "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> > > > > undefined symbols in the "config input", but I can't find one that
> > > > > catches undefined symbols in the Kconfig tree itself.
> > > > >
> > > > > That is, the tool seems to allow this.
> > > > > However, if this turns out to be a major problem. I think we
> > > > > can either:
> > > > > - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> > > > >   the only dependency. Then add ARCH_GOOGLE back
> > > > >   later once it's in the tree.
> > > >
> > > > Please do this.  I do not want to take patches that purposfully add
> > > > dependencies on config options that might, or might not, appear in the
> > > > future.  Please just remove all of the dependancies for now, as they are
> > > > not needed, right?
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > >
> > > Greg,
> > >
> > > Yes, we can remove ARCH_GOOGLE for now.
> > > To clarify, we're not removing all of the dependencies, we still want
> > > to keep COMPILE_TEST for build tests, right?
> > > Please let me know if you think otherwise.
> >
> > I think you'd just remove all of them. Normally COMPILE_TEST just
> > allows folks to compile stuff even when they don't want the ARCH. We
> > can can add ARCH_GOOGLE back in later once the config exists.
> >
> > -Doug
> 
> Doug,
> 
> Thanks for chiming in. I'm hesitant to remove COMPILE_TEST
> because Greg specifically requested its inclusion in v7 [1].
> Also it seems beneficial to get some build coverage before
> ARCH_GOOGLE is officially added to the tree.
> Greg, could you clarify?

I wanted it in because it would not build without it on a non "google"
system.  But now, as that option isn't there, just don't have any
dependency, as it's obviously not needed.

thanks,

greg k-h

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Krzysztof Kozlowski]

On 18/12/2025 02:34, Roy Luo wrote:
> On Wed, Dec 17, 2025 at 12:14 PM Doug Anderson <dianders@google.com> wrote:
>>
>> Hi,
>>
>> On Wed, Dec 17, 2025 at 11:18 AM Roy Luo <royluo@google.com> wrote:
>>>
>>> On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
>>> <gregkh@linuxfoundation.org> wrote:
>>>>
>>>> On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
>>>>> On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
>>>>> <gregkh@linuxfoundation.org> wrote:
>>>>>>
>>>>>> On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
>>>>>>> +config USB_DWC3_GOOGLE
>>>>>>> +     tristate "Google Platform"
>>>>>>> +     depends on ARCH_GOOGLE || COMPILE_TEST
>>>>>>
>>>>>> There is no ARCH_GOOGLE in the tree now, so how is this supposed to
>>>>>> work?  Shouldn't tools that check for "invalid config options" trigger
>>>>>> on this?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> greg k-h
>>>>>
>>>>> Hi Greg,
>>>>>
>>>>> The menuconfig looks like the following and it doesn't complain:
>>>>> | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
>>>>> | Type  : unknown
>>>>> |
>>>>> | Symbol: PHY_GOOGLE_USB [=y]
>>>>> | Type  : tristate
>>>>> | Defined at drivers/phy/Kconfig:104
>>>>> |     Prompt: Google Tensor SoC USB PHY driver
>>>>> |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
>>>>>
>>>>> According to Kconfig documentation [1], the unknown symbol
>>>>> would simply be evaluated as an "n", which is what we want.
>>>>> "Convert the symbol into an expression. Boolean and tristate
>>>>> symbols are simply converted into the respective expression
>>>>> values. All other symbol types result in ‘n’."
>>>>>
>>>>> In a different Kconfig documentation, an environment variable
>>>>> "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
>>>>> undefined symbols in the "config input", but I can't find one that
>>>>> catches undefined symbols in the Kconfig tree itself.
>>>>>
>>>>> That is, the tool seems to allow this.
>>>>> However, if this turns out to be a major problem. I think we
>>>>> can either:
>>>>> - Remove ARCH_GOOGLE and leave COMPILE_TEST as
>>>>>   the only dependency. Then add ARCH_GOOGLE back
>>>>>   later once it's in the tree.
>>>>
>>>> Please do this.  I do not want to take patches that purposfully add
>>>> dependencies on config options that might, or might not, appear in the
>>>> future.  Please just remove all of the dependancies for now, as they are
>>>> not needed, right?
>>>>
>>>> thanks,
>>>>
>>>> greg k-h
>>>
>>> Greg,
>>>
>>> Yes, we can remove ARCH_GOOGLE for now.
>>> To clarify, we're not removing all of the dependencies, we still want
>>> to keep COMPILE_TEST for build tests, right?
>>> Please let me know if you think otherwise.
>>
>> I think you'd just remove all of them. Normally COMPILE_TEST just
>> allows folks to compile stuff even when they don't want the ARCH. We
>> can can add ARCH_GOOGLE back in later once the config exists.
>>
>> -Doug
> 
> Doug,
> 
> Thanks for chiming in. I'm hesitant to remove COMPILE_TEST
> because Greg specifically requested its inclusion in v7 [1].


What? No, that's not what Greg requested. Your COMPILE_TEST in current
form helps nothing in build testing. It makes absolutely no sense at all.

> Also it seems beneficial to get some build coverage before
> ARCH_GOOGLE is officially added to the tree.

And COMPILE_TEST like you wrote it does not give you that. Please first
read how this function works.

> Greg, could you clarify?

Can you first look at Linux kernel sources to see how this is properly
written?

> 
> [1] https://lore.kernel.org/linux-usb/2025112144-claw-recolor-49c3@gregkh/
> 
> Thanks,
> Roy


Best regards,
Krzysztof

Re: [PATCH v9 2/2] usb: dwc3: Add Google Tensor SoC DWC3 glue driver

[Roy Luo]

On Wed, Dec 17, 2025 at 11:06 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On 18/12/2025 02:34, Roy Luo wrote:
> > On Wed, Dec 17, 2025 at 12:14 PM Doug Anderson <dianders@google.com> wrote:
> >>
> >> Hi,
> >>
> >> On Wed, Dec 17, 2025 at 11:18 AM Roy Luo <royluo@google.com> wrote:
> >>>
> >>> On Wed, Dec 17, 2025 at 5:24 AM Greg Kroah-Hartman
> >>> <gregkh@linuxfoundation.org> wrote:
> >>>>
> >>>> On Thu, Dec 04, 2025 at 11:14:39PM -0800, Roy Luo wrote:
> >>>>> On Thu, Dec 4, 2025 at 10:05 PM Greg Kroah-Hartman
> >>>>> <gregkh@linuxfoundation.org> wrote:
> >>>>>>
> >>>>>> On Fri, Dec 05, 2025 at 02:26:38AM +0000, Roy Luo wrote:
> >>>>>>> +config USB_DWC3_GOOGLE
> >>>>>>> +     tristate "Google Platform"
> >>>>>>> +     depends on ARCH_GOOGLE || COMPILE_TEST
> >>>>>>
> >>>>>> There is no ARCH_GOOGLE in the tree now, so how is this supposed to
> >>>>>> work?  Shouldn't tools that check for "invalid config options" trigger
> >>>>>> on this?
> >>>>>>
> >>>>>> thanks,
> >>>>>>
> >>>>>> greg k-h
> >>>>>
> >>>>> Hi Greg,
> >>>>>
> >>>>> The menuconfig looks like the following and it doesn't complain:
> >>>>> | Symbol: ARCH_GOOGLE [=ARCH_GOOGLE]
> >>>>> | Type  : unknown
> >>>>> |
> >>>>> | Symbol: PHY_GOOGLE_USB [=y]
> >>>>> | Type  : tristate
> >>>>> | Defined at drivers/phy/Kconfig:104
> >>>>> |     Prompt: Google Tensor SoC USB PHY driver
> >>>>> |     Depends on: ARCH_GOOGLE || COMPILE_TEST [=y]
> >>>>>
> >>>>> According to Kconfig documentation [1], the unknown symbol
> >>>>> would simply be evaluated as an "n", which is what we want.
> >>>>> "Convert the symbol into an expression. Boolean and tristate
> >>>>> symbols are simply converted into the respective expression
> >>>>> values. All other symbol types result in ‘n’."
> >>>>>
> >>>>> In a different Kconfig documentation, an environment variable
> >>>>> "KCONFIG_WARN_UNKNOWN_SYMBOLS" is there to detect
> >>>>> undefined symbols in the "config input", but I can't find one that
> >>>>> catches undefined symbols in the Kconfig tree itself.
> >>>>>
> >>>>> That is, the tool seems to allow this.
> >>>>> However, if this turns out to be a major problem. I think we
> >>>>> can either:
> >>>>> - Remove ARCH_GOOGLE and leave COMPILE_TEST as
> >>>>>   the only dependency. Then add ARCH_GOOGLE back
> >>>>>   later once it's in the tree.
> >>>>
> >>>> Please do this.  I do not want to take patches that purposfully add
> >>>> dependencies on config options that might, or might not, appear in the
> >>>> future.  Please just remove all of the dependancies for now, as they are
> >>>> not needed, right?
> >>>>
> >>>> thanks,
> >>>>
> >>>> greg k-h
> >>>
> >>> Greg,
> >>>
> >>> Yes, we can remove ARCH_GOOGLE for now.
> >>> To clarify, we're not removing all of the dependencies, we still want
> >>> to keep COMPILE_TEST for build tests, right?
> >>> Please let me know if you think otherwise.
> >>
> >> I think you'd just remove all of them. Normally COMPILE_TEST just
> >> allows folks to compile stuff even when they don't want the ARCH. We
> >> can can add ARCH_GOOGLE back in later once the config exists.
> >>
> >> -Doug
> >
> > Doug,
> >
> > Thanks for chiming in. I'm hesitant to remove COMPILE_TEST
> > because Greg specifically requested its inclusion in v7 [1].
>
>
> What? No, that's not what Greg requested. Your COMPILE_TEST in current
> form helps nothing in build testing. It makes absolutely no sense at all.
>
> > Also it seems beneficial to get some build coverage before
> > ARCH_GOOGLE is officially added to the tree.
>
> And COMPILE_TEST like you wrote it does not give you that. Please first
> read how this function works.
>
> > Greg, could you clarify?
>
> Can you first look at Linux kernel sources to see how this is properly
> written?
>
> >
> > [1] https://lore.kernel.org/linux-usb/2025112144-claw-recolor-49c3@gregkh/
> >
> > Thanks,
> > Roy
>
>
> Best regards,
> Krzysztof

Greg and Krzysztof,

Thanks for the clarification.

Regards,
Roy