Add Google Tensor SoC USB controller support

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 <[email protected]>

---
 .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
 MAINTAINERS                                        |   1 +
 2 files changed, 141 insertions(+)

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 <[email protected]>

---
 .../devicetree/bindings/usb/google,lga-dwc3.yaml   | 140 +++++++++++++++++++++
 MAINTAINERS                                        |   1 +
 2 files changed, 141 insertions(+)

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+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

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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$

Quoted 48 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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).

Quoted 3 lines

[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

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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

Quoted 55 lines · Greg Kroah-Hartman

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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,

Quoted 1 line

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.

Hi,

Quoted 58 lines · Roy Luo

Quoted 55 lines · Greg Kroah-Hartman

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

drivers/usb/dwc3/Kconfig config USB_DWC3_GENERIC_PLAT · line 205

Quoted 3 lines · Roy Luo

drivers/usb/dwc3/Kconfig +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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,

Quoted 8 lines

Quoted 1 line

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

Quoted 71 lines · Doug Anderson

Hi,

Quoted 58 lines · Roy Luo

Quoted 55 lines · Greg Kroah-Hartman

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

Review

Quoted 3 lines · Roy Luo

(quoted diff) +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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,

Quoted 8 lines

Quoted 1 line

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.

Quoted 5 lines

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?

Quoted 75 lines · Doug Anderson

Hi,

Quoted 58 lines · Roy Luo

Quoted 55 lines · Greg Kroah-Hartman

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

Review

Quoted 3 lines · Roy Luo

(quoted diff) +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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,

Quoted 8 lines

Quoted 1 line

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.

Quoted 1 line

-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

Quoted 76 lines · Roy Luo

Quoted 75 lines · Doug Anderson

Hi,

Quoted 58 lines · Roy Luo

Quoted 55 lines · Greg Kroah-Hartman

Quoted 39 lines · Roy Luo

Quoted 6 lines · Greg Kroah-Hartman

Review

Quoted 3 lines · Roy Luo

(quoted diff) +3 -0

+config USB_DWC3_GOOGLE
+     tristate "Google Platform"
+     depends on ARCH_GOOGLE || COMPILE_TEST

Quoted 7 lines

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.

Quoted 6 lines

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,

Quoted 8 lines

Quoted 1 line

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.

Quoted 6 lines

Quoted 1 line

-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.

Quoted 2 lines

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.

Quoted 1 line

Greg, could you clarify?

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

Quoted 1 line

Quoted 4 lines

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

Thanks,
Roy

Best regards,
Krzysztof