[PATCH 3/6] net: arc_emac: support the phy reset for emac driver

Caesar Wang
2016-03-11T10:55:28Z

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-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
---

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);
+}
+#else
+static void emac_reset_phy(struct platform_device *pdev)
+{
+}
+#endif /* CONFIG_OF */
+
int arc_emac_probe(struct net_device *ndev, int interface)
{
struct device *dev = ndev->dev.parent;
@@ -803,6 +842,8 @@ int arc_emac_probe(struct net_device *ndev, int interface)
/* FIXME :: no multicast support yet */
ndev->flags &= ~IFF_MULTICAST;

+ emac_reset_phy(ndev);
+
priv = netdev_priv(ndev);
priv->dev = dev;

--
1.9.1