Re: [PATCH net-next v3 14/14] net: dsa: b53: ensure BCM5325 PHYs are enabled

[Jonas Gorski]

On Thu, Jun 12, 2025 at 10:38 AM Álvaro Fernández Rojas
<noltari@xxxxxxxxx> wrote:
>
> According to the datasheet, BCM5325 uses B53_PD_MODE_CTRL_25 register to
> disable clocking to individual PHYs.
> Only ports 1-4 can be enabled or disabled and the datasheet is explicit
> about not toggling BIT(0) since it disables the PLL power and the switch.
>
> Signed-off-by: Álvaro Fernández Rojas <noltari@xxxxxxxxx>
> ---
>  drivers/net/dsa/b53/b53_common.c | 12 ++++++++++++
>  drivers/net/dsa/b53/b53_regs.h   |  2 ++
>  2 files changed, 14 insertions(+)
>
>  v3: add changes requested by Florian:
>   - Use in_range() helper.
>
>  v2: add changes requested by Florian:
>   - Move B53_PD_MODE_CTRL_25 to b53_setup_port().
>
> diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
> index 3503f363e2419..eac40e95c8c53 100644
> --- a/drivers/net/dsa/b53/b53_common.c
> +++ b/drivers/net/dsa/b53/b53_common.c
> @@ -660,6 +660,18 @@ int b53_setup_port(struct dsa_switch *ds, int port)
>         if (dsa_is_user_port(ds, port))
>                 b53_set_eap_mode(dev, port, EAP_MODE_SIMPLIFIED);
>
> +       if (is5325(dev) &&
> +           in_range(port, B53_PD_MODE_PORT_MIN, B53_PD_MODE_PORT_MAX)) {

This happen to match, but the third argument of in_range() isn't the
maximum, but the range (max - start), so semantically this looks
wrong.

> +               u8 reg;
> +
> +               b53_read8(dev, B53_CTRL_PAGE, B53_PD_MODE_CTRL_25, &reg);
> +               if (dsa_is_unused_port(ds, port))
> +                       reg |= BIT(port);
> +               else
> +                       reg &= ~BIT(port);
> +               b53_write8(dev, B53_CTRL_PAGE, B53_PD_MODE_CTRL_25, reg);
> +       }
> +
>         return 0;
>  }
>  EXPORT_SYMBOL(b53_setup_port);
> diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
> index d6849cf6b0a3a..880c67130a9fc 100644
> --- a/drivers/net/dsa/b53/b53_regs.h
> +++ b/drivers/net/dsa/b53/b53_regs.h
> @@ -105,6 +105,8 @@
>
>  /* Power-down mode control */
>  #define B53_PD_MODE_CTRL_25            0x0f
> +#define  B53_PD_MODE_PORT_MIN          1
> +#define  B53_PD_MODE_PORT_MAX          4
>
>  /* IP Multicast control (8 bit) */
>  #define B53_IP_MULTICAST_CTRL          0x21
> --
> 2.39.5
>

Regards,
Jonas