From: Sekhar Nori <nsekhar@ti.com>
Date: Thu, 23 Aug 2018 11:41:29 +0000 (+0530)
Subject: drivers: net: cpsw: add support to update phy address
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=e2597be5bcb90030fdc116e7c5810bdef7fd9e0d;p=u-boot.git

drivers: net: cpsw: add support to update phy address

On some boards using TI CPSW, it may be possible that
PHY address was not latched correctly, and the actual
address that the phy responds on is different from that
set in device-tree. For example, see this problem report
on beaglebone black:

https://groups.google.com/d/msg/beagleboard/9mctrG26Mc8/1FuI_i5KW10J

Add support to check for this condition and use the
detected phy address when its safe to do so.

Also, add a public API that exposes the phy address of
a given slave. This can be used to update device-tree that
is passed to Linux kernel.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
---

diff --git a/drivers/net/cpsw.c b/drivers/net/cpsw.c
index c31695eba9..8e2a48cfd6 100644
--- a/drivers/net/cpsw.c
+++ b/drivers/net/cpsw.c
@@ -1008,6 +1008,25 @@ static int cpsw_phy_init(struct cpsw_priv *priv, struct cpsw_slave *slave)
 	return 1;
 }
 
+static void cpsw_phy_addr_update(struct cpsw_priv *priv)
+{
+	struct cpsw_platform_data *data = &priv->data;
+	u16 alive = mdio_regs->alive & GENMASK(15, 0);
+	int active = data->active_slave;
+	int new_addr = ffs(alive) - 1;
+
+	/*
+	 * If there is only one phy alive and its address does not match
+	 * that of active slave, then phy address can safely be updated.
+	 */
+	if (hweight16(alive) == 1 &&
+	    data->slave_data[active].phy_addr != new_addr) {
+		printf("Updated phy address for CPSW#%d, old: %d, new: %d\n",
+		       active, data->slave_data[active].phy_addr, new_addr);
+		data->slave_data[active].phy_addr = new_addr;
+	}
+}
+
 int _cpsw_register(struct cpsw_priv *priv)
 {
 	struct cpsw_slave	*slave;
@@ -1034,6 +1053,9 @@ int _cpsw_register(struct cpsw_priv *priv)
 	}
 
 	cpsw_mdio_init(priv->dev->name, data->mdio_base, data->mdio_div);
+
+	cpsw_phy_addr_update(priv);
+
 	priv->bus = miiphy_get_dev_by_name(priv->dev->name);
 	for_active_slave(slave, priv)
 		cpsw_phy_init(priv, slave);
@@ -1458,6 +1480,13 @@ static int cpsw_eth_ofdata_to_platdata(struct udevice *dev)
 	return 0;
 }
 
+int cpsw_get_slave_phy_addr(struct udevice *dev, int slave)
+{
+	struct cpsw_priv *priv = dev_get_priv(dev);
+	struct cpsw_platform_data *data = &priv->data;
+
+	return data->slave_data[slave].phy_addr;
+}
 
 static const struct udevice_id cpsw_eth_ids[] = {
 	{ .compatible = "ti,cpsw" },
diff --git a/include/cpsw.h b/include/cpsw.h
index f135e7bfe0..9f8ce8850f 100644
--- a/include/cpsw.h
+++ b/include/cpsw.h
@@ -54,5 +54,6 @@ struct cpsw_platform_data {
 
 int cpsw_register(struct cpsw_platform_data *data);
 int ti_cm_get_macid(struct udevice *dev, int slave, u8 *mac_addr);
+int cpsw_get_slave_phy_addr(struct udevice *dev, int slave);
 
 #endif /* _CPSW_H_  */