• Greg Ungerer's avatar
    net: fec: make use of MDIO C45 quirk · abc33494
    Greg Ungerer authored
    Not all fec MDIO bus drivers support C45 mode transactions. The older fec
    hardware block in many ColdFire SoCs does not appear to support them, at
    least according to most of the different ColdFire SoC reference manuals.
    The bits used to generate C45 access on the iMX parts, in the OP field
    of the MMFR register, are documented as generating non-compliant MII
    frames (it is not documented as to exactly how they are non-compliant).
    
    Commit 8d03ad1a ("net: fec: Separate C22 and C45 transactions")
    means the fec driver will always register c45 MDIO read and write
    methods. During probe these will always be accessed now generating
    non-compliant MII accesses on ColdFire based devices.
    
    Add a quirk define, FEC_QUIRK_HAS_MDIO_C45, that can be used to
    distinguish silicon that supports MDIO C45 framing or not. Add this to
    all the existing iMX quirks, so they will be behave as they do now (*).
    
    (*) it seems that some iMX parts may not support C45 transactions either.
        The iMX25 and iMX50 Reference Manuals contain similar wording to
        the ColdFire Reference Manuals on this.
    
    Fixes: 8d03ad1a ("net: fec: Separate C22 and C45 transactions")
    Signed-off-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
    Reviewed-by: default avatarWei Fang <wei.fang@nxp.com>
    Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
    Link: https://lore.kernel.org/r/20230404052207.3064861-1-gerg@linux-m68k.orgSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    abc33494
fec.h 26.3 KB