On Sun, Oct 13, 2024 at 11:27:39PM +0200, Jan Petrous via B4 Relay wrote:
> From: "Jan Petrous (OSS)" <jan.petrous@xxxxxxxxxxx>
>
> 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);
>
> Suggested-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
> Signed-off-by: Jan Petrous (OSS) <jan.petrous@xxxxxxxxxxx>
But of an unusual commit message, but it does explain the "Why?".
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
>
> +/**
> + * rgmii_clock - map link speed to the clock rate
> + * @speed: link speed value
> + *
> + * Description: maps RGMII supported link speeds
> + * into the clock rates.
> + */
A Returns: line would be nice.
Andrew
