Hi Caesar, Am Freitag, 11. M?rz 2016, 16:47:59 schrieb Sergei Shtylyov: > On 3/11/2016 1:55 PM, Caesar Wang wrote: > > This patch adds to support the emac phy reset. > > > > 1) phy-reset-gpios: > > The phy-reset-gpios is an optional property for arc emac device tree boot. > > Change the binding document to match the driver code. > > > > 2) phy-reset-duration: > > Different boards may require different phy reset duration. Add property > > phy-reset-duration for device tree probe, so that the boards that need > > a longer reset duration can specify it in their device tree. > > > > 3) phy-reset-active-high: > > We need that for a custom hardware that needs the reverse reset sequence. > > > > Of course, this patch will fix the issue on > > https://patchwork.kernel.org/patch/8186801/. > > > > In some cases, the emac couldn't work if you don't have reset the phy. > > Let's add it to happy work. > > > > Signed-off-by: Caesar Wang <wxt at rock-chips.com> > > --- > > > > drivers/net/ethernet/arc/emac_main.c | 41 > > ++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) > > > > diff --git a/drivers/net/ethernet/arc/emac_main.c > > b/drivers/net/ethernet/arc/emac_main.c index 6446af1..42384f6a 100644 > > --- a/drivers/net/ethernet/arc/emac_main.c > > +++ b/drivers/net/ethernet/arc/emac_main.c > > @@ -764,6 +764,45 @@ static const struct net_device_ops > > arc_emac_netdev_ops = {> > > #endif > > }; > > > > +#ifdef CONFIG_OF > > +static void emac_reset_phy(struct net_device *pdev) > > +{ > > + int err, phy_reset; > > + bool active_high = false; > > + int msec = 10; > > + struct device *dev = pdev->dev.parent; > > + struct device_node *np = dev->of_node; > > + > > + if (!np) > > + return; > > + > > + of_property_read_u32(np, "phy-reset-duration", &msec); > > + /* A sane reset duration should not be longer than 1s */ > > + if (msec > 1000) > > + msec = 1; > > + > > + phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0); > > + if (!gpio_is_valid(phy_reset)) > > + return; > > + > > + active_high = of_property_read_bool(np, "phy-reset-active-high"); > > + > > + err = devm_gpio_request_one(dev, phy_reset, active_high ? > > + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, > > + "phy-reset"); > > + if (err) { > > + dev_err(dev, "failed to get phy-reset-gpios: %d\n", err); > > + return; > > + } > > + msleep(msec); > > + gpio_set_value_cansleep(phy_reset, !active_high); > > +} > > [...] > > Why not make it the mii_bus::reset() method? It gets called before the > MDIO bus scan. while meddling with the emac, I've built some sort of preliminary variant of Sergei's suggestion at [0] - maybe you could take a look for some sort of inspiration ;-) The code is lifted from the designware gmac driver, so the binding also is similar. Heiko [0] https://github.com/mmind/linux-rockchip/commit/a943c588783438ff1c508dfa8c79f1709aa5775e
