On some SoC platforms, in shutdown stage, most components' power is cut
off, but there's still power supply to the so called always-on
domain, so if the dwc2's regulator is from the always-on domain, we
need to explicitly disable it to save power.

Disable platform lowlevel hw resources such as phy, clock and
regulators etc. in device shutdown hook to reduce non-necessary power
consumption when the platform enters shutdown stage.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 drivers/usb/dwc2/platform.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 12b4dc07d08a..3f83ecc9fc23 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -371,6 +371,9 @@ static void dwc2_driver_shutdown(struct platform_device *dev)
 
 	dwc2_disable_global_interrupts(hsotg);
 	synchronize_irq(hsotg->irq);
+
+	if (hsotg->ll_hw_enabled)
+		dwc2_lowlevel_hw_disable(hsotg);
 }
 
 /**
-- 
2.49.0

On 6/29/25 13:46, Jisheng Zhang wrote:
> On some SoC platforms, in shutdown stage, most components' power is cut
> off, but there's still power supply to the so called always-on
> domain, so if the dwc2's regulator is from the always-on domain, we
> need to explicitly disable it to save power.
> 
> Disable platform lowlevel hw resources such as phy, clock and
> regulators etc. in device shutdown hook to reduce non-necessary power
> consumption when the platform enters shutdown stage.
> 
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>

Acked-by: Minas Harutyunyan <hminas@synopsys.com>

> ---
>   drivers/usb/dwc2/platform.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index 12b4dc07d08a..3f83ecc9fc23 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -371,6 +371,9 @@ static void dwc2_driver_shutdown(struct platform_device *dev)
>   
>   	dwc2_disable_global_interrupts(hsotg);
>   	synchronize_irq(hsotg->irq);
> +
> +	if (hsotg->ll_hw_enabled)
> +		dwc2_lowlevel_hw_disable(hsotg);
>   }
>   
>   /**