[PATCH v3 net-next] net: ethernet: ti: davinci_mdio: Add workaround for errata i2329

[Andrew Lunn]

On Wed, Aug 17, 2022 at 03:14:06PM +0530, Ravi Gunasekaran wrote:
> On the CPSW and ICSS peripherals, there is a possibility that the MDIO
> interface returns corrupt data on MDIO reads or writes incorrect data
> on MDIO writes. There is also a possibility for the MDIO interface to
> become unavailable until the next peripheral reset.
> 
> The workaround is to configure the MDIO in manual mode and disable the
> MDIO state machine and emulate the MDIO protocol by reading and writing
> appropriate fields in MDIO_MANUAL_IF_REG register of the MDIO controller
> to manipulate the MDIO clock and data pins.
> 
> More details about the errata i2329 and the workaround is available in:
> https://www.ti.com/lit/er/sprz487a/sprz487a.pdf
> 
> Add implementation to disable MDIO state machine, configure MDIO in manual
> mode and achieve MDIO read and writes via MDIO Bitbanging
> 
> Signed-off-by: Ravi Gunasekaran <r-gunasekaran at ti.com>
> Reported-by: kernel test robot <lkp at intel.com>

Reviewed-by: Andrew Lunn <andrew at lunn.ch>

    Andrew