net: phylink: add pcs_pre_config()/pcs_post_config() methods

Add hooks that are called before and after the mac_config() call,
which will be needed to deal with errata workarounds for the
Marvell 88e639x DSA switches.

Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/phy/phylink.c

···
 	}
 }
 
+static void phylink_pcs_pre_config(struct phylink_pcs *pcs,
+				   phy_interface_t interface)
+{
+	if (pcs && pcs->ops->pcs_pre_config)
+		pcs->ops->pcs_pre_config(pcs, interface);
+}
+
+static int phylink_pcs_post_config(struct phylink_pcs *pcs,
+				   phy_interface_t interface)
+{
+	int err = 0;
+
+	if (pcs && pcs->ops->pcs_post_config)
+		err = pcs->ops->pcs_post_config(pcs, interface);
+
+	return err;
+}
+
 static void phylink_pcs_disable(struct phylink_pcs *pcs)
 {
 	if (pcs && pcs->ops->pcs_disable)
···
 		pl->pcs = pcs;
 	}
 
+	if (pl->pcs)
+		phylink_pcs_pre_config(pl->pcs, state->interface);
+
 	phylink_mac_config(pl, state);
+
+	if (pl->pcs)
+		phylink_pcs_post_config(pl->pcs, state->interface);
 
 	if (pl->pcs_state == PCS_STATE_STARTING || pcs_changed)
 		phylink_pcs_enable(pl->pcs);

include/linux/phylink.h

···
  * @pcs_validate: validate the link configuration.
  * @pcs_enable: enable the PCS.
  * @pcs_disable: disable the PCS.
+ * @pcs_pre_config: pre-mac_config method (for errata)
+ * @pcs_post_config: post-mac_config method (for arrata)
  * @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.
···
 			    const struct phylink_link_state *state);
 	int (*pcs_enable)(struct phylink_pcs *pcs);
 	void (*pcs_disable)(struct phylink_pcs *pcs);
+	void (*pcs_pre_config)(struct phylink_pcs *pcs,
+			       phy_interface_t interface);
+	int (*pcs_post_config)(struct phylink_pcs *pcs,
+			       phy_interface_t interface);
 	void (*pcs_get_state)(struct phylink_pcs *pcs,
 			      struct phylink_link_state *state);
 	int (*pcs_config)(struct phylink_pcs *pcs, unsigned int neg_mode,