[PATCH net-next v2 13/14] net: stmmac: provide PCS initialisation hook

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

dwmac cores provide a feature bit to indicate when the PCS block is
present, but features are only read after the core's setup() function
has been called, meaning we can't decide whether to initialise the
integrated PCS in the setup function. Provide a new MAC core hook
for PCS initialisation, which will be called after the feature
registers have been read.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/hwif.h        | 4 ++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 7796f5f3c96f..82cfb6bec334 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -313,6 +313,8 @@ enum stmmac_lpi_mode {
 
 /* Helpers to program the MAC core */
 struct stmmac_ops {
+	/* Initialise any PCS instances */
+	int (*pcs_init)(struct stmmac_priv *priv);
 	/* MAC core initialization */
 	void (*core_init)(struct mac_device_info *hw, struct net_device *dev);
 	/* Update MAC capabilities */
@@ -413,6 +415,8 @@ struct stmmac_ops {
 					u32 pclass);
 };
 
+#define stmmac_mac_pcs_init(__priv) \
+	stmmac_do_callback(__priv, mac, pcs_init, __priv)
 #define stmmac_core_init(__priv, __args...) \
 	stmmac_do_void_callback(__priv, mac, core_init, __args)
 #define stmmac_mac_update_caps(__priv) \
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c3633baf5180..35cd881b3496 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7238,6 +7238,13 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
 			 "Enable RX Mitigation via HW Watchdog Timer\n");
 	}
 
+	/* Unimplemented PCS init (as indicated by stmmac_do_callback()
+	 * perversely returning -EINVAL) is non-fatal.
+	 */
+	ret = stmmac_mac_pcs_init(priv);
+	if (ret != -EINVAL)
+		return ret;
+
 	return 0;
 }
 
-- 
2.47.3