net: phylink: add separate pcs operations structure

Add a separate set of PCS operations, which MAC drivers can use to
couple phylink with their associated MAC PCS layer.  The PCS
operations include:

- pcs_get_state() - reads the link up/down, resolved speed, duplex
   and pause from the PCS.
- pcs_config() - configures the PCS for the specified mode, PHY
   interface type, and setting the advertisement.
- pcs_an_restart() - restarts 802.3 in-band negotiation with the
   link partner
- pcs_link_up() - informs the PCS that link has come up, and the
   parameters of the link. Link parameters are used to program the
   PCS for fixed speed and non-inband modes.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

2 files changed, 143 insertions, 22 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index a8a6fd33b8bb..d830108f7a8e 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -41,6 +41,7 @@ struct phylink {
 	/* private: */
 	struct net_device *netdev;
 	const struct phylink_mac_ops *mac_ops;
+	const struct phylink_pcs_ops *pcs_ops;
 	struct phylink_config *config;
 	struct device *dev;
 	unsigned int old_link_state:1;
@@ -420,11 +421,32 @@ static void phylink_mac_config_up(struct phylink *pl,
 		phylink_mac_config(pl, state);
 }
 
-static void phylink_mac_an_restart(struct phylink *pl)
+static void phylink_mac_pcs_an_restart(struct phylink *pl)
 {
 	if (pl->link_config.an_enabled &&
-	    phy_interface_mode_is_8023z(pl->link_config.interface))
-		pl->mac_ops->mac_an_restart(pl->config);
+	    phy_interface_mode_is_8023z(pl->link_config.interface)) {
+		if (pl->pcs_ops)
+			pl->pcs_ops->pcs_an_restart(pl->config);
+		else
+			pl->mac_ops->mac_an_restart(pl->config);
+	}
+}
+
+static void phylink_pcs_config(struct phylink *pl, bool force_restart,
+			       const struct phylink_link_state *state)
+{
+	bool restart = force_restart;
+
+	if (pl->pcs_ops && pl->pcs_ops->pcs_config(pl->config,
+						   pl->cur_link_an_mode,
+						   state->interface,
+						   state->advertising))
+		restart = true;
+
+	phylink_mac_config(pl, state);
+
+	if (restart)
+		phylink_mac_pcs_an_restart(pl);
 }
 
 static void phylink_mac_pcs_get_state(struct phylink *pl,
@@ -440,7 +462,10 @@ static void phylink_mac_pcs_get_state(struct phylink *pl,
 	state->an_complete = 0;
 	state->link = 1;
 
-	pl->mac_ops->mac_pcs_get_state(pl->config, state);
+	if (pl->pcs_ops)
+		pl->pcs_ops->pcs_get_state(pl->config, state);
+	else
+		pl->mac_ops->mac_pcs_get_state(pl->config, state);
 }
 
 /* The fixed state is... fixed except for the link state,
@@ -458,7 +483,7 @@ static void phylink_get_fixed_state(struct phylink *pl,
 	phylink_resolve_flow(state);
 }
 
-static void phylink_mac_initial_config(struct phylink *pl)
+static void phylink_mac_initial_config(struct phylink *pl, bool force_restart)
 {
 	struct phylink_link_state link_state;
 
@@ -484,7 +509,7 @@ static void phylink_mac_initial_config(struct phylink *pl)
 	link_state.link = false;
 
 	phylink_apply_manual_flow(pl, &link_state);
-	phylink_mac_config(pl, &link_state);
+	phylink_pcs_config(pl, force_restart, &link_state);
 }
 
 static const char *phylink_pause_to_str(int pause)
@@ -501,12 +526,18 @@ static const char *phylink_pause_to_str(int pause)
 	}
 }
 
-static void phylink_mac_link_up(struct phylink *pl,
-				struct phylink_link_state link_state)
+static void phylink_link_up(struct phylink *pl,
+			    struct phylink_link_state link_state)
 {
 	struct net_device *ndev = pl->netdev;
 
 	pl->cur_interface = link_state.interface;
+
+	if (pl->pcs_ops && pl->pcs_ops->pcs_link_up)
+		pl->pcs_ops->pcs_link_up(pl->config, pl->cur_link_an_mode,
+					 pl->cur_interface,
+					 link_state.speed, link_state.duplex);
+
 	pl->mac_ops->mac_link_up(pl->config, pl->phydev,
 				 pl->cur_link_an_mode, pl->cur_interface,
 				 link_state.speed, link_state.duplex,
@@ -523,7 +554,7 @@ static void phylink_mac_link_up(struct phylink *pl,
 		     phylink_pause_to_str(link_state.pause));
 }
 
-static void phylink_mac_link_down(struct phylink *pl)
+static void phylink_link_down(struct phylink *pl)
 {
 	struct net_device *ndev = pl->netdev;
 
@@ -592,9 +623,9 @@ static void phylink_resolve(struct work_struct *w)
 	if (link_changed) {
 		pl->old_link_state = link_state.link;
 		if (!link_state.link)
-			phylink_mac_link_down(pl);
+			phylink_link_down(pl);
 		else
-			phylink_mac_link_up(pl, link_state);
+			phylink_link_up(pl, link_state);
 	}
 	if (!link_state.link && pl->mac_link_dropped) {
 		pl->mac_link_dropped = false;
@@ -741,6 +772,12 @@ struct phylink *phylink_create(struct phylink_config *config,
 }
 EXPORT_SYMBOL_GPL(phylink_create);
 
+void phylink_add_pcs(struct phylink *pl, const struct phylink_pcs_ops *ops)
+{
+	pl->pcs_ops = ops;
+}
+EXPORT_SYMBOL_GPL(phylink_add_pcs);
+
 /**
  * phylink_destroy() - cleanup and destroy the phylink instance
  * @pl: a pointer to a &struct phylink returned from phylink_create()
@@ -1077,14 +1114,12 @@ void phylink_start(struct phylink *pl)
 	/* Apply the link configuration to the MAC when starting. This allows
 	 * a fixed-link to start with the correct parameters, and also
 	 * ensures that we set the appropriate advertisement for Serdes links.
-	 */
-	phylink_mac_initial_config(pl);
-
-	/* Restart autonegotiation if using 802.3z to ensure that the link
+	 *
+	 * Restart autonegotiation if using 802.3z to ensure that the link
 	 * parameters are properly negotiated.  This is necessary for DSA
 	 * switches using 802.3z negotiation to ensure they see our modes.
 	 */
-	phylink_mac_an_restart(pl);
+	phylink_mac_initial_config(pl, true);
 
 	clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
 	phylink_run_resolve(pl);
@@ -1381,8 +1416,7 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
 			 * advertisement; the only thing we have is the pause
 			 * modes which can only come from a PHY.
 			 */
-			phylink_mac_config(pl, &pl->link_config);
-			phylink_mac_an_restart(pl);
+			phylink_pcs_config(pl, true, &pl->link_config);
 		}
 		mutex_unlock(&pl->state_mutex);
 	}
@@ -1410,7 +1444,7 @@ int phylink_ethtool_nway_reset(struct phylink *pl)
 
 	if (pl->phydev)
 		ret = phy_restart_aneg(pl->phydev);
-	phylink_mac_an_restart(pl);
+	phylink_mac_pcs_an_restart(pl);
 
 	return ret;
 }
@@ -1489,8 +1523,7 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 				   pause->tx_pause);
 	} else if (!test_bit(PHYLINK_DISABLE_STOPPED,
 			     &pl->phylink_disable_state)) {
-		phylink_mac_config(pl, &pl->link_config);
-		phylink_mac_an_restart(pl);
+		phylink_pcs_config(pl, true, &pl->link_config);
 	}
 	mutex_unlock(&pl->state_mutex);
 
@@ -1896,7 +1929,7 @@ static int phylink_sfp_config(struct phylink *pl, u8 mode,
 
 	if (changed && !test_bit(PHYLINK_DISABLE_STOPPED,
 				 &pl->phylink_disable_state))
-		phylink_mac_initial_config(pl);
+		phylink_mac_initial_config(pl, false);
 
 	return ret;
 }
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 90c907eaae15..3f8d37ec5503 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -270,9 +270,97 @@ void mac_link_up(struct phylink_config *config, struct phy_device *phy,
 		 int speed, int duplex, bool tx_pause, bool rx_pause);
 #endif
 
+/**
+ * struct phylink_pcs_ops - MAC PCS operations structure.
+ * @pcs_get_state: read the current MAC PCS link state from the hardware.
+ * @pcs_config: configure the MAC PCS for the selected mode and state.
+ * @pcs_an_restart: restart 802.3z BaseX autonegotiation.
+ * @pcs_link_up: program the PCS for the resolved link configuration
+ *               (where necessary).
+ */
+struct phylink_pcs_ops {
+	void (*pcs_get_state)(struct phylink_config *config,
+			      struct phylink_link_state *state);
+	int (*pcs_config)(struct phylink_config *config, unsigned int mode,
+			  phy_interface_t interface,
+			  const unsigned long *advertising);
+	void (*pcs_an_restart)(struct phylink_config *config);
+	void (*pcs_link_up)(struct phylink_config *config, unsigned int mode,
+			    phy_interface_t interface, int speed, int duplex);
+};
+
+#if 0 /* For kernel-doc purposes only. */
+/**
+ * pcs_get_state() - Read the current inband link state from the hardware
+ * @config: a pointer to a &struct phylink_config.
+ * @state: a pointer to a &struct phylink_link_state.
+ *
+ * Read the current inband link state from the MAC PCS, reporting the
+ * current speed in @state->speed, duplex mode in @state->duplex, pause
+ * mode in @state->pause using the %MLO_PAUSE_RX and %MLO_PAUSE_TX bits,
+ * negotiation completion state in @state->an_complete, and link up state
+ * in @state->link. If possible, @state->lp_advertising should also be
+ * populated.
+ *
+ * When present, this overrides mac_pcs_get_state() in &struct
+ * phylink_mac_ops.
+ */
+void pcs_get_state(struct phylink_config *config,
+		   struct phylink_link_state *state);
+
+/**
+ * pcs_config() - Configure the PCS mode and advertisement
+ * @config: a pointer to a &struct phylink_config.
+ * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
+ * @interface: interface mode to be used
+ * @advertising: adertisement ethtool link mode mask
+ *
+ * Configure the PCS for the operating mode, the interface mode, and set
+ * the advertisement mask.
+ *
+ * When operating in %MLO_AN_INBAND, inband should always be enabled,
+ * otherwise inband should be disabled.
+ *
+ * For SGMII, there is no advertisement from the MAC side, the PCS should
+ * be programmed to acknowledge the inband word from the PHY.
+ *
+ * For 1000BASE-X, the advertisement should be programmed into the PCS.
+ *
+ * For most 10GBASE-R, there is no advertisement.
+ */
+int (*pcs_config)(struct phylink_config *config, unsigned int mode,
+		  phy_interface_t interface, const unsigned long *advertising);
+
+/**
+ * pcs_an_restart() - restart 802.3z BaseX autonegotiation
+ * @config: a pointer to a &struct phylink_config.
+ *
+ * When PCS ops are present, this overrides mac_an_restart() in &struct
+ * phylink_mac_ops.
+ */
+void (*pcs_an_restart)(struct phylink_config *config);
+
+/**
+ * pcs_link_up() - program the PCS for the resolved link configuration
+ * @config: a pointer to a &struct phylink_config.
+ * @mode: link autonegotiation mode
+ * @interface: link &typedef phy_interface_t mode
+ * @speed: link speed
+ * @duplex: link duplex
+ *
+ * This call will be made just before mac_link_up() to inform the PCS of
+ * the resolved link parameters. For example, a PCS operating in SGMII
+ * mode without in-band AN needs to be manually configured for the link
+ * and duplex setting. Otherwise, this should be a no-op.
+ */
+void (*pcs_link_up)(struct phylink_config *config, unsigned int mode,
+		    phy_interface_t interface, int speed, int duplex);
+#endif
+
 struct phylink *phylink_create(struct phylink_config *, struct fwnode_handle *,
 			       phy_interface_t iface,
 			       const struct phylink_mac_ops *mac_ops);
+void phylink_add_pcs(struct phylink *, const struct phylink_pcs_ops *ops);
 void phylink_destroy(struct phylink *);
 
 int phylink_connect_phy(struct phylink *, struct phy_device *);