Re: [PATCH v3 net-next 2/2] net: airoha: Introduce ethernet support for EN7581 SoC

Andrew Lunn
2024-06-24T15:45:49Z

On Mon, Jun 24, 2024 at 01:01:44AM +0200, Benjamin Larsson wrote:
> Hi,
> > Code like this is making me wounder about the split between MAC
> > driver, DSA driver and DSA tag driver. Or if it should actually be a
> > pure switchdev driver?
> >
> > If there some open architecture documentation for this device?
> >
> > What are these ports about?
> >
> > > +static int airoha_dev_open(struct net_device *dev)
> > > +{
> > > + struct airoha_eth *eth = netdev_priv(dev);
> > > + int err;
> > > +
> > > + if (netdev_uses_dsa(dev))
> > > + airoha_fe_set(eth, REG_GDM1_INGRESS_CFG, GDM1_STAG_EN_MASK);
> > > + else
> > > + airoha_fe_clear(eth, REG_GDM1_INGRESS_CFG, GDM1_STAG_EN_MASK);
> > Does that imply both instances of the GMAC are not connected to the
> > switch? Can one be used with a PHY?
> >
> > Andrew
>
> https://mirror2.openwrt.org/docs/MT7981B_Wi-Fi6_Platform_Datasheet_Open_V1.0.pdf
>
> page 107 (text for 9.1.1 is relevant but not a complete match). In the
> EN7581 case there is a 5 port switch in the place of GMAC1 (one switch port
> is connected to GDM1).

The typical DSA architecture is that the SoC MAC is connected to a
switch MAC port. You say here, the switch is directly connected to the
GGM1. So there is no GMAC involved? If there is no MAC, you don't need
a MAC driver.

It seems more likely there is a GMAC, and the SGMII interface, or
something similar is connected to the switch?

Andrew