[PATCH v2] phy: renesas: rcar-gen3-usb2: Simplify ID/VBUS detection logic

[Lad, Prabhakar]

Hi Vinod,

On Wed, Mar 25, 2026 at 11:20 AM Prabhakar <prabhakar.csengg at gmail.com> wrote:
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
>
> Read USB2_ADPCTRL once in rcar_gen3_check_id() instead of issuing
> multiple MMIO reads, and derive both IDDIG and VBUSVALID from the same
> value.
>
> Drop the redundant !! operator, as assigning a masked u32 value to a
> bool already performs the required normalization. Simplify the logic by
> comparing the ID and VBUS status directly, which is equivalent to the
> previous conditional but easier to follow.
>
> Reported-by: Pavel Machek <pavel at nabladev.com>
> Closes: https://lore.kernel.org/all/acJVCOdlchLiSe5n@duo.ucw.cz/
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
> ---
> v1->v2:
> - Rebased on top of latest next-20260324
> - Combined variable declarations and assignments and dropped
>   redundant !! operator
> - Updated commit message
> - Corrected the link for closes tag
> ---
>  drivers/phy/renesas/phy-rcar-gen3-usb2.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
>
Gentle ping.

Cheers,
Prabhakar

> diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> index 79e820e2fe55..9a45d840efeb 100644
> --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> @@ -314,13 +314,11 @@ static void rcar_gen3_init_from_a_peri_to_a_host(struct rcar_gen3_chan *ch)
>  static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
>  {
>         if (ch->phy_data->vblvl_ctrl) {
> -               bool vbus_valid;
> -               bool device;
> +               u32 val = readl(ch->base + USB2_ADPCTRL);
> +               bool vbus_valid = val & USB2_ADPCTRL_VBUSVALID;
> +               bool device = val & USB2_ADPCTRL_IDDIG;
>
> -               device = !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
> -               vbus_valid = !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_VBUSVALID);
> -
> -               return vbus_valid ? device : !device;
> +               return device == vbus_valid;
>         }
>
>         if (!ch->uses_otg_pins)
> --
> 2.53.0
>