[PATCH v2 4/7] net: phy: add helper for mapping RGMII link speed to clock rate

[Jan Petrous]

On Mon, Aug 19, 2024 at 03:15:41PM +0100, Simon Horman wrote:
> On Sun, Aug 18, 2024 at 09:50:46PM +0000, Jan Petrous (OSS) wrote:
> > The helper rgmii_clock() implemented Russel's hint during stmmac
> > glue driver review:
> > 
> > ---
> > We seem to have multiple cases of very similar logic in lots of stmmac
> > platform drivers, and I think it's about time we said no more to this.
> > So, what I think we should do is as follows:
> > 
> > add the following helper - either in stmmac, or more generically
> > (phylib? - in which case its name will need changing.)
> > 
> > static long stmmac_get_rgmii_clock(int speed)
> > {
> > 	switch (speed) {
> > 	case SPEED_10:
> > 		return 2500000;
> > 
> > 	case SPEED_100:
> > 		return 25000000;
> > 
> > 	case SPEED_1000:
> > 		return 125000000;
> > 
> > 	default:
> > 		return -ENVAL;
> > 	}
> > }
> > 
> > Then, this can become:
> > 
> > 	long tx_clk_rate;
> > 
> > 	...
> > 
> > 	tx_clk_rate = stmmac_get_rgmii_clock(speed);
> > 	if (tx_clk_rate < 0) {
> > 		dev_err(gmac->dev, "Unsupported/Invalid speed: %d\n", speed);
> > 		return;
> > 	}
> > 
> > 	ret = clk_set_rate(gmac->tx_clk, tx_clk_rate);
> > ---
> > 
> > Signed-off-by: Jan Petrous (OSS) <jan.petrous at oss.nxp.com>
> > ---
> >  include/linux/phy.h | 21 +++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> > 
> > diff --git a/include/linux/phy.h b/include/linux/phy.h
> > index 6b7d40d49129..bb797364d91c 100644
> > --- a/include/linux/phy.h
> > +++ b/include/linux/phy.h
> > @@ -298,6 +298,27 @@ static inline const char *phy_modes(phy_interface_t interface)
> >  	}
> >  }
> >  
> > +/**
> > + * rgmi_clock - map link speed to the clock rate
> 
> nit: rgmii_clock
> 
>      Flagged by ./scripts/kernel-doc -none
> 

Thanks. Fixed in v3.

BR.
/Jan