Re: [PATCH v3 1/1] usb: dwc3: Add optional VBUS regulator support to SpacemiT K1

[Troy Mitchell <troy.mitchell@linux.spacemit.com>]

On Thu, Mar 26, 2026 at 18:00:10 CST, Chukun Pan wrote:
> Some SpacemiT K1 boards (like OrangePi R2S) provide USB VBUS
> through a controllable regulator. Add support for the optional
> vbus-supply property so the regulator can be properly managed
> in host mode instead of left always-on. Note that this doesn't
> apply to USB Hub downstream ports with different VBUS supplies.
> 
> The enabled and disabled actions of the regulator are handled
> automatically by devm_regulator_get_enable_optional().
> 
> Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
> ---
>  drivers/usb/dwc3/dwc3-generic-plat.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
> index e846844e0023..64f5e9f20663 100644
> --- a/drivers/usb/dwc3/dwc3-generic-plat.c
> +++ b/drivers/usb/dwc3/dwc3-generic-plat.c
> @@ -12,6 +12,8 @@
>  #include <linux/reset.h>
>  #include <linux/regmap.h>
>  #include <linux/mfd/syscon.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/usb/otg.h>
>  #include "glue.h"
>  
>  #define EIC7700_HSP_BUS_FILTER_EN	BIT(0)
> @@ -69,6 +71,20 @@ static int dwc3_eic7700_init(struct dwc3_generic *dwc3g)
>  	return 0;
>  }
>  
> +static int dwc3_spacemit_k1_init(struct dwc3_generic *dwc3g)
> +{
> +	struct device *dev = dwc3g->dev;
> +
> +	if (usb_get_dr_mode(dev) == USB_DR_MODE_HOST) {
The logic looks good, but the structure can be further improved to better align with
standard kernel coding style:

if (usb_get_dr_mode(dev) != USB_DR_MODE_HOST)
  return 0;
> +		int ret = devm_regulator_get_enable_optional(dev, "vbus");
Could you please move the declaration of ret to the top of the function?

Otherwise, LGTM.
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>