On Fri, Sep 11, 2020 at 09:48:50PM +0800, Landen Chao wrote:

This patch series adds support for MT7531.

MT7531 is the next generation of MT7530 which could be found on Mediatek
router platforms such as MT7622 or MT7629.

It is also a 7-ports switch with 5 giga embedded phys, 2 cpu ports, and
the same MAC logic of MT7530. Cpu port 6 only supports SGMII interface.
Cpu port 5 supports either RGMII or SGMII in different HW SKU, but cannot
be muxed to PHY of port 0/4 like mt7530. Due to support for SGMII
interface, pll, and pad setting are different from MT7530.

MT7531 SGMII interface can be configured in following mode:
- 'SGMII AN mode' with in-band negotiation capability
    which is compatible with PHY_INTERFACE_MODE_SGMII.
- 'SGMII force mode' without in-band negotiation
    which is compatible with 10B/8B encoding of
    PHY_INTERFACE_MODE_1000BASEX with fixed full-duplex and fixed pause.
- 2.5 times faster clocked 'SGMII force mode' without in-band negotiation
    which is compatible with 10B/8B encoding of
    PHY_INTERFACE_MODE_2500BASEX with fixed full-duplex and fixed pause.

v4 -> v5
- Add fixed-link node to dsa cpu port in dts file by suggestion of
  Vladimir Oltean.

Thank you!

-Vladimir