[PATCH v3 1/2] net: fec: Add possibility to enable TXC delay

[Philippe Schenker]

On Fri, 2020-04-17 at 18:35 +0200, Stefano Babic wrote:
> Hi Philippe,
> 
> On 11/03/20 11:52, Philippe Schenker wrote:
> > This patch enables the possibility to set FEC_ENET_ENABLE_TXC_DELAY
> > or
> > FEC_ENET_ENABLE_RXC_DELAY so one can via a define enable the RXC or
> > TXC
> > delay in the MAC.
> > 
> > Signed-off-by: Philippe Schenker <philippe.schenker at toradex.com>
> > Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov at toradex.com>
> > 
> > ---
> > 
> > Changes in v3:
> > - Add Olek's reviewed-by tag
> > 
> > Changes in v2: None
> > 
> >  drivers/net/fec_mxc.c | 10 ++++++++++
> >  drivers/net/fec_mxc.h |  2 ++
> >  2 files changed, 12 insertions(+)
> > 
> > diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
> > index bc5b63d7881..345d37be4e8 100644
> > --- a/drivers/net/fec_mxc.c
> > +++ b/drivers/net/fec_mxc.c
> > @@ -503,6 +503,16 @@ static int fec_open(struct eth_device *edev)
> >  	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_ETHER_EN,
> >  	       &fec->eth->ecntrl);
> >  
> > +#ifdef FEC_ENET_ENABLE_TXC_DELAY
> > +	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_TXC_DLY,
> > +	       &fec->eth->ecntrl);
> > +#endif
> > +
> > +#ifdef FEC_ENET_ENABLE_RXC_DELAY
> > +	writel(readl(&fec->eth->ecntrl) | FEC_ECNTRL_RXC_DLY,
> > +	       &fec->eth->ecntrl);
> > +#endif
> > +
> >  #if defined(CONFIG_MX25) || defined(CONFIG_MX53) ||
> > defined(CONFIG_MX6SL)
> >  	udelay(100);
> >  
> > diff --git a/drivers/net/fec_mxc.h b/drivers/net/fec_mxc.h
> > index 159aec89679..3c8fdda2638 100644
> > --- a/drivers/net/fec_mxc.h
> > +++ b/drivers/net/fec_mxc.h
> > @@ -188,6 +188,8 @@ struct ethernet_regs {
> >  #define FEC_ECNTRL_ETHER_EN		0x00000002	/* enable
> > the FEC */
> >  #define FEC_ECNTRL_SPEED		0x00000020
> >  #define FEC_ECNTRL_DBSWAP		0x00000100
> > +#define FEC_ECNTRL_TXC_DLY		0x00010000	/* TXC delayed */
> > +#define FEC_ECNTRL_RXC_DLY		0x00020000	/* RXC delayed */
> >  
> >  #define FEC_X_WMRK_STRFWD		0x00000100
> >  
> > 
> 
> But these are not exactly the properties removed by verdin-imx8mm in
> DTS, that is for example rgmii_rxc_dly ? And then, should not be
> better
> to support it in DT instead of a CONFIG_ ?

Hi Stefano,

I'll add Igor in cc as I'm not that familiar with most recent
development on u-boot. Yes you are right. Those tags (rgmii_rxc_dly) are
exactly the same. However they came in from our downstream branch and
were never meant for mainline u-boot. We dropped them in favor of the
proper phy-mode 'rgmii-id' in linux. Those originally probably also
originated from our downstream linux branch...

But U-Boot does not support phy-modes on KSZ PHYs so I felt this was a
straight forward and easy solution for u-boot that we can enable as soon
as we have our new PHY KSZ9131 on our board. At the moment there is
KSZ9031 placed which does indeed not support this.

Regards,
Philippe
> 
> Regards,
> Stefano
>