Currently for fixed-link the link state is always set to UP.
This patch introduces the new property 'link' that accepts the
following string arguments: "up", "down" and "auto".
"down" may be needed if the link is physically unconnected.
"auto" is needed to enable the link paramaters auto-negotiation,
that is built into some MII protocols, namely SGMII.
The appropriate documentation is added and explicitly states that
"auto" is very specific (protocol, HW and driver-specific), and
is therefore should be used with care.
Signed-off-by: Stas Sergeev <s...@users.sourceforge.net>
CC: Rob Herring <robh...@kernel.org>
CC: Pawel Moll <pawel.m...@arm.com>
CC: Mark Rutland <mark.rutl...@arm.com>
CC: Ian Campbell <ijc+devicet...@hellion.org.uk>
CC: Kumar Gala <ga...@codeaurora.org>
CC: Florian Fainelli <f.faine...@gmail.com>
CC: Grant Likely <grant.lik...@linaro.org>
CC: devicet...@vger.kernel.org
CC: linux-ker...@vger.kernel.org
CC: netdev@vger.kernel.org
---
.../devicetree/bindings/net/fixed-link.txt | 8 +++-
drivers/of/of_mdio.c | 48 ++++++++++++++++++++--
include/linux/of_mdio.h | 5 +++
3 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/fixed-link.txt
b/Documentation/devicetree/bindings/net/fixed-link.txt
index 82bf7e0..070f554 100644
--- a/Documentation/devicetree/bindings/net/fixed-link.txt
+++ b/Documentation/devicetree/bindings/net/fixed-link.txt
@@ -9,8 +9,14 @@ Such a fixed link situation is described by creating a
'fixed-link'
sub-node of the Ethernet MAC device node, with the following
properties:
+* 'link' (string, optional), to indicate the link state. Accepted
+ values are "up", "down" and "auto". "auto" means auto-negotiation of
+ link parameters. Auto-negotiation is MII protocol, HW and driver-specific
+ and is not supported in many cases, so use it only when you know what
+ you do.
* 'speed' (integer, mandatory), to indicate the link speed. Accepted
- values are 10, 100 and 1000
+ values are 10, 100 and 1000. If the 'link' property is set to 'auto',
+ 'speed' may not be set. It will then be auto-negotiated, if possible.
* 'full-duplex' (boolean, optional), to indicate that full duplex is
used. When absent, half duplex is assumed.
* 'pause' (boolean, optional), to indicate that pause should be
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 1bd4305..2152cf8 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -280,6 +280,26 @@ bool of_phy_is_fixed_link(struct device_node *np)
}
EXPORT_SYMBOL(of_phy_is_fixed_link);
+bool of_phy_is_autoneg_link(struct device_node *np)
+{
+ struct device_node *dn;
+ const char *link_str;
+ int rc;
+ bool ret = false;
+
+ dn = of_get_child_by_name(np, "fixed-link");
+ if (!dn)
+ return false;
+
+ rc = of_property_read_string(dn, "link", &link_str);
+ if (rc == 0 && strcmp(link_str, "auto") == 0)
+ ret = true;
+
+ of_node_put(dn);
+ return ret;
+}
+EXPORT_SYMBOL(of_phy_is_autoneg_link);
+
int of_phy_register_fixed_link(struct device_node *np)
{
struct fixed_phy_status status = {};
@@ -291,11 +311,33 @@ int of_phy_register_fixed_link(struct device_node *np)
/* New binding */
fixed_link_node = of_get_child_by_name(np, "fixed-link");
if (fixed_link_node) {
- status.link = 1;
+ const char *link_str;
+ int ret;
+ bool link_auto = false;
+
+ ret = of_property_read_string(fixed_link_node, "link",
+ &link_str);
+ if (ret == 0) {
+ if (strcmp(link_str, "up") == 0)
+ status.link = 1;
+ else
+ status.link = 0;
+ if (strcmp(link_str, "auto") == 0)
+ link_auto = true;
+ } else {
+ status.link = 1;
+ }
status.duplex = of_property_read_bool(fixed_link_node,
"full-duplex");
- if (of_property_read_u32(fixed_link_node, "speed",
&status.speed))
- return -EINVAL;
+ if (of_property_read_u32(fixed_link_node, "speed",
+ &status.speed) != 0) {
+ /* in auto mode just set to some sane value:
+ * it will be changed by MAC later */
+ if (link_auto)
+ status.speed = 1000;
+ else
+ return -EINVAL;
+ }
status.pause = of_property_read_bool(fixed_link_node, "pause");
status.asym_pause = of_property_read_bool(fixed_link_node,
"asym-pause");
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index d449018..647f348 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -65,6 +65,7 @@ static inline struct mii_bus *of_mdio_find_bus(struct
device_node *mdio_np)
#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)
extern int of_phy_register_fixed_link(struct device_node *np);
extern bool of_phy_is_fixed_link(struct device_node *np);
+extern bool of_phy_is_autoneg_link(struct device_node *np);
#else
static inline int of_phy_register_fixed_link(struct device_node *np)
{
@@ -74,6 +75,10 @@ static inline bool of_phy_is_fixed_link(struct device_node
*np)
{
return false;
}
+static inline bool of_phy_is_autoneg_link(struct device_node *np)
+{
+ return false;
+}
#endif
--
1.9.1
--
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