Re: [PATCH v2] net: dsa: mv88e6xxx: support RGMII cmode

From: Marek Behún
Date: Fri Aug 19 2022 - 14:19:57 EST


On Fri, 19 Aug 2022 15:56:29 +0200
Marcus Carlberg <marcus.carlberg@xxxxxxxx> wrote:

> Since the probe defaults all interfaces to the highest speed possible
> (10GBASE-X in mv88e6393x) before the phy mode configuration from the
> devicetree is considered it is currently impossible to use port 0 in
> RGMII mode.
>
> This change will allow RGMII modes to be configurable for port 0
> enabling port 0 to be configured as RGMII as well as serial depending
> on configuration.
>
> Signed-off-by: Marcus Carlberg <marcus.carlberg@xxxxxxxx>
> ---
>
> Notes:
> v2: add phy mode input validation for SERDES only ports
>
> drivers/net/dsa/mv88e6xxx/port.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c
> index 90c55f23b7c9..5c4195c635b0 100644
> --- a/drivers/net/dsa/mv88e6xxx/port.c
> +++ b/drivers/net/dsa/mv88e6xxx/port.c
> @@ -517,6 +517,12 @@ static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
> case PHY_INTERFACE_MODE_RMII:
> cmode = MV88E6XXX_PORT_STS_CMODE_RMII;
> break;
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + cmode = MV88E6XXX_PORT_STS_CMODE_RGMII;
> + break;
> case PHY_INTERFACE_MODE_1000BASEX:
> cmode = MV88E6XXX_PORT_STS_CMODE_1000BASEX;
> break;
> @@ -634,6 +640,19 @@ int mv88e6393x_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
> if (port != 0 && port != 9 && port != 10)
> return -EOPNOTSUPP;
>
> + if (port == 9 || port == 10) {
> + switch (mode) {
> + case PHY_INTERFACE_MODE_RMII:
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + return -EINVAL;
> + default:
> + break;
> + }
> + }
> +
> /* mv88e6393x errata 4.5: EEE should be disabled on SERDES ports */
> err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_MAC_CTL, &reg);
> if (err)

You also need to change
mv88e6393x_phylink_get_caps in chip.c
to add RGMII interface types to the supported bit field if port == 0,
because the mv88e6xxx_translate_cmode() call does not fill RGMII as
supported there if cmode isn't RGMII at the beginning.

Also this should have Fixes tag?

Marek