[PATCH v3] net: tsec: add option to set device max-speed via dts

[Aleksandar Gerasimovski]

Current tsec adapter sets adapter gigabit capabilities by default, and in
reality this must not always be the case.
It is possible that tsec adapter is used for 100Mbps connection, and in
this case setting 1000Mbps capabilities can lead to some side effects such
longer autoneg process.

In our ls102x designs this problem leads to long autoneg times (> 4 sec)
in case board rgmii link is 100Mbps capable only.
Limiting the rgmii link capabilities provides faster and smoother
link establishment.

Signed-off-by: Aleksandar Gerasimovski <aleksandar.gerasimovski at hitachi-powergrids.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean at nxp.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes for v2:
  - keep the variable sort order in a decreasing order of line length
  - fix comment typo
Changes for v3:
  - fix commit message typos
---
 drivers/net/tsec.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/tsec.c b/drivers/net/tsec.c
index c68e4b7..ee820aa 100644
--- a/drivers/net/tsec.c
+++ b/drivers/net/tsec.c
@@ -828,6 +828,7 @@ int tsec_probe(struct udevice *dev)
 	const char *phy_mode;
 	ofnode parent, child;
 	fdt_addr_t reg;
+	u32 max_speed;
 	int ret;
 
 	data = (struct tsec_data *)dev_get_driver_data(dev);
@@ -893,8 +894,12 @@ int tsec_probe(struct udevice *dev)
 	}
 	priv->interface = pdata->phy_interface;
 
+	/* Check for speed limit, default is 1000Mbps */
+	max_speed = dev_read_u32_default(dev, "max-speed", 1000);
+
 	/* Initialize flags */
-	priv->flags = TSEC_GIGABIT;
+	if (max_speed == 1000)
+		priv->flags = TSEC_GIGABIT;
 	if (priv->interface == PHY_INTERFACE_MODE_SGMII)
 		priv->flags |= TSEC_SGMII;
 
-- 
1.8.3.1