[U-Boot] [PATCH v4 6/6] net: macb: Extend MACB driver for SiFive Unleashed board

[Anup Patel <anup@brainfault.org>]

On Wed, Jun 19, 2019 at 3:32 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> Hi Anup,
>
> On Wed, Jun 19, 2019 at 4:26 PM Anup Patel <Anup.Patel@wdc.com> wrote:
> >
> > The SiFive MACB ethernet has a custom TX_CLK_SEL register to select
> > different TX clock for 1000mbps vs 10/100mbps.
> >
> > This patch adds SiFive MACB compatible string and extends the MACB
> > ethernet driver to change TX clock using TX_CLK_SEL register for
> > SiFive MACB.
> >
> > Signed-off-by: Anup Patel <anup.patel@wdc.com>
> > ---
> >  drivers/net/macb.c | 38 +++++++++++++++++++++++++++-----------
> >  drivers/net/macb.h |  1 +
> >  2 files changed, 28 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> > index c5560a7111..31f4d71793 100644
> > --- a/drivers/net/macb.c
> > +++ b/drivers/net/macb.c
> > @@ -107,6 +107,7 @@ struct macb_device {
> >         unsigned int            tx_tail;
> >         unsigned int            next_rx_tail;
> >         bool                    wrapped;
> > +       bool                    is_sifive_macb;
> >
> >         void                    *rx_buffer;
> >         void                    *tx_buffer;
> > @@ -498,18 +499,11 @@ static int macb_phy_find(struct macb_device *macb, const char *name)
> >  int __weak macb_linkspd_cb(struct udevice *dev, unsigned int speed)
> >  {
> >  #ifdef CONFIG_CLK
> > +       struct macb_device *macb = dev_get_priv(dev);
> >         struct clk tx_clk;
> >         ulong rate;
> >         int ret;
> >
> > -       /*
> > -        * "tx_clk" is an optional clock source for MACB.
> > -        * Ignore if it does not exist in DT.
> > -        */
> > -       ret = clk_get_by_name(dev, "tx_clk", &tx_clk);
> > -       if (ret)
> > -               return 0;
> > -
> >         switch (speed) {
> >         case _10BASET:
> >                 rate = 2500000;         /* 2.5 MHz */
> > @@ -525,10 +519,29 @@ int __weak macb_linkspd_cb(struct udevice *dev, unsigned int speed)
> >                 return 0;
> >         }
> >
> > -       if (tx_clk.dev) {
> > -               ret = clk_set_rate(&tx_clk, rate);
> > +       if (macb->is_sifive_macb) {
> > +               /*
> > +                * GEMGXL TX clock operation mode:
> > +                *
> > +                * 0 = GMII mode. Use 125 MHz gemgxlclk from PRCI in TX logic
> > +                *     and output clock on GMII output signal GTX_CLK
> > +                * 1 = MII mode. Use MII input signal TX_CLK in TX logic
> > +                */
> > +               macb_writel(macb, SIFIVE_TX_CLK_SEL, rate != 125000000);
> > +       } else {
> > +               /*
> > +                * "tx_clk" is an optional clock source for MACB.
> > +                * Ignore if it does not exist in DT.
> > +                */
> > +               ret = clk_get_by_name(dev, "tx_clk", &tx_clk);
> >                 if (ret)
> > -                       return ret;
> > +                       return 0;
> > +
> > +               if (tx_clk.dev) {
> > +                       ret = clk_set_rate(&tx_clk, rate);
> > +                       if (ret)
> > +                               return ret;
> > +               }
> >         }
> >  #endif
> >
> > @@ -1147,6 +1160,8 @@ static int macb_eth_probe(struct udevice *dev)
> >         const char *phy_mode;
> >         __maybe_unused int ret;
> >
> > +       macb->is_sifive_macb = device_is_compatible(dev, "sifive,fu540-macb");
> > +
> >         phy_mode = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "phy-mode",
> >                                NULL);
> >         if (phy_mode)
> > @@ -1225,6 +1240,7 @@ static const struct udevice_id macb_eth_ids[] = {
> >         { .compatible = "atmel,sama5d3-gem" },
> >         { .compatible = "atmel,sama5d4-gem" },
> >         { .compatible = "cdns,zynq-gem" },
> > +       { .compatible = "sifive,fu540-macb" },
> >         { }
> >  };
> >
> > diff --git a/drivers/net/macb.h b/drivers/net/macb.h
> > index 3cc27f8560..c3903010df 100644
> > --- a/drivers/net/macb.h
> > +++ b/drivers/net/macb.h
> > @@ -57,6 +57,7 @@
> >  #define MACB_USRIO                             0x00c0
> >  #define MACB_WOL                               0x00c4
> >  #define MACB_MID                               0x00fc
> > +#define MACB_SIFIVE_TX_CLK_SEL                 0x10000
>
> The Linux SiFive macb device bindings says: "For "sifive,fu540-macb",
> second range is required to specify the address and length of the
> registers for GEMGXL Management block.". So in order to really keep
> sync with Linux driver, a second reg needs to be parsed from DT.

I was able to find a way to do this in U-Boot DM drivers.

Any suggestions??

Regards,
Anup