[PATCH 2/2] net: smc911x: Determine bus width at runtime

[Ramon Fried]

On Tue, Jun 29, 2021 at 2:18 PM Ramon Fried <rfried.dev at gmail.com> wrote:
>
> On Mon, Jun 28, 2021 at 4:31 PM Andre Przywara <andre.przywara at arm.com> wrote:
> >
> > The SMC911x Ethernet MACs can be integrated using a 16 or 32-bit bus.
> > The driver needs to know about this choice, which is the reason for us
> > having a Kconfig symbol for that.
> >
> > Now this bus width is already described using a devicetree property, and
> > since the driver is DM compliant and is using the DT now, we should query
> > this at runtime. We leave the Kconfig choice around, in case the DT is
> > missing this property.
> >
> > Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> > ---
> >  drivers/net/smc911x.c | 33 ++++++++++++++++++++-------------
> >  1 file changed, 20 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/net/smc911x.c b/drivers/net/smc911x.c
> > index d596d96f4b3..3afebee4402 100644
> > --- a/drivers/net/smc911x.c
> > +++ b/drivers/net/smc911x.c
> > @@ -28,6 +28,7 @@ struct smc911x_priv {
> >         phys_addr_t             iobase;
> >         const struct chip_id    *chipid;
> >         unsigned char           enetaddr[6];
> > +       bool                    use_32_bit_io;
> >  };
> >
> >  static const struct chip_id chip_ids[] =  {
> > @@ -48,28 +49,24 @@ static const struct chip_id chip_ids[] =  {
> >
> >  #define DRIVERNAME "smc911x"
> >
> > -#if defined (CONFIG_SMC911X_32_BIT)
> >  static u32 smc911x_reg_read(struct smc911x_priv *priv, u32 offset)
> >  {
> > -       return readl(priv->iobase + offset);
> > -}
> > +       if (priv->use_32_bit_io)
> > +               return readl(priv->iobase + offset);
> >
> > -static void smc911x_reg_write(struct smc911x_priv *priv, u32 offset, u32 val)
> > -{
> > -       writel(val, priv->iobase + offset);
> > -}
> > -#else
> > -static u32 smc911x_reg_read(struct smc911x_priv *priv, u32 offset)
> > -{
> >         return (readw(priv->iobase + offset) & 0xffff) |
> >                (readw(priv->iobase + offset + 2) << 16);
> >  }
> > +
> >  static void smc911x_reg_write(struct smc911x_priv *priv, u32 offset, u32 val)
> >  {
> > -       writew(val & 0xffff, priv->iobase + offset);
> > -       writew(val >> 16, priv->iobase + offset + 2);
> > +       if (priv->use_32_bit_io) {
> > +               writel(val, priv->iobase + offset);
> > +       } else {
> > +               writew(val & 0xffff, priv->iobase + offset);
> > +               writew(val >> 16, priv->iobase + offset + 2);
> > +       }
> >  }
> > -#endif /* CONFIG_SMC911X_32_BIT */
> >
> >  static u32 smc911x_get_mac_csr(struct smc911x_priv *priv, u8 reg)
> >  {
> > @@ -493,6 +490,8 @@ int smc911x_initialize(u8 dev_num, int base_addr)
> >         priv->iobase = base_addr;
> >         priv->dev.iobase = base_addr;
> >
> > +       priv->use_32_bit_io = CONFIG_IS_ENABLED(SMC911X_32_BIT);
> > +
> >         /* Try to detect chip. Will fail if not present. */
> >         ret = smc911x_detect_chip(priv);
> >         if (ret) {
> > @@ -603,10 +602,18 @@ static int smc911x_of_to_plat(struct udevice *dev)
> >  {
> >         struct smc911x_priv *priv = dev_get_priv(dev);
> >         struct eth_pdata *pdata = dev_get_plat(dev);
> > +       u32 io_width;
> > +       int ret;
> >
> >         pdata->iobase = dev_read_addr(dev);
> >         priv->iobase = pdata->iobase;
> >
> > +       ret = dev_read_u32(dev, "reg-io-width", &io_width);
> > +       if (!ret)
> > +               priv->use_32_bit_io = (io_width == 4);
> > +       else
> > +               priv->use_32_bit_io = CONFIG_IS_ENABLED(SMC911X_32_BIT);
> > +
> >         return 0;
> >  }
> >
> > --
> > 2.17.5
> >
> Reviewed-by: Ramon Fried <rfried.dev at gmail.com>
Applied to u-boot-net/master, Thanks !
Ramon