[PATCH net-next V4 1/5] net: phylink: Add phylink_set_fixed_link() to configure fixed link state in phylink

From: Raju Lakkaraju
Date: Thu Aug 29 2024 - 01:58:41 EST


From: Russell King <linux@xxxxxxxxxxxxxxx>

The function allows for the configuration of a fixed link state for a given
phylink instance. This addition is particularly useful for network devices that
operate with a fixed link configuration, where the link parameters do not change
dynamically. By using `phylink_set_fixed_link()`, drivers can easily set up
the fixed link state during initialization or configuration changes.

Signed-off-by: Russell King <linux@xxxxxxxxxxxxxxx>
Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@xxxxxxxxxxxxx>
---
Change List:
============
V0 -> V1:
- Change phylink fixed-link function header's string from "Returns" to
"Returns:"
- Add fixed-link patch along with this series.
Note: Note: This code was developed by Mr.Russell King
Ref:
https://lore.kernel.org/netdev/LV8PR11MB8700C786F5F1C274C73036CC9F8E2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#me943adf54f1ea082edf294aba448fa003a116815

drivers/net/phy/phylink.c | 42 +++++++++++++++++++++++++++++++++++++++
include/linux/phylink.h | 2 ++
2 files changed, 44 insertions(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index ab4e9fc03017..4309317de3d1 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1635,6 +1635,48 @@ static int phylink_register_sfp(struct phylink *pl,
return ret;
}

+/**
+ * phylink_set_fixed_link() - set the fixed link
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ * @state: a pointer to a struct phylink_link_state.
+ *
+ * This function is used when the link parameters are known and do not change,
+ * making it suitable for certain types of network connections.
+ *
+ * Returns: zero on success or negative error code.
+ */
+int phylink_set_fixed_link(struct phylink *pl,
+ const struct phylink_link_state *state)
+{
+ const struct phy_setting *s;
+ unsigned long *adv;
+
+ if (pl->cfg_link_an_mode != MLO_AN_PHY || !state ||
+ !test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
+ return -EINVAL;
+
+ s = phy_lookup_setting(state->speed, state->duplex,
+ pl->supported, true);
+ if (!s)
+ return -EINVAL;
+
+ adv = pl->link_config.advertising;
+ linkmode_zero(adv);
+ linkmode_set_bit(s->bit, adv);
+ linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, adv);
+
+ pl->link_config.speed = state->speed;
+ pl->link_config.duplex = state->duplex;
+ pl->link_config.link = 1;
+ pl->link_config.an_complete = 1;
+
+ pl->cfg_link_an_mode = MLO_AN_FIXED;
+ pl->cur_link_an_mode = pl->cfg_link_an_mode;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(phylink_set_fixed_link);
+
/**
* phylink_create() - create a phylink instance
* @config: a pointer to the target &struct phylink_config
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 2381e07429a2..5c01048860c4 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -598,6 +598,8 @@ int phylink_fwnode_phy_connect(struct phylink *pl,
const struct fwnode_handle *fwnode,
u32 flags);
void phylink_disconnect_phy(struct phylink *);
+int phylink_set_fixed_link(struct phylink *,
+ const struct phylink_link_state *);

void phylink_mac_change(struct phylink *, bool up);
void phylink_pcs_change(struct phylink_pcs *, bool up);
--
2.34.1