[PATCH RFC net-next v3 4/8] net: stmmac: use integrated PCS for BASE-X modes

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

dwmac-qcom-ethqos supports SGMII and 2500BASE-X using the integrated
PCS, so we need to expand the PCS support to include support for
BASE-X modes.

Add support to the prereset configuration to detect 2500BASE-X, and
arrange for stmmac_mac_select_pcs() to return the integrated PCS if
its supported_interfaces bitmap reports support for the interface mode.

This results in priv->hw->pcs now being write-only, so remove it.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/common.h      | 4 ----
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 46454e2886ce..b7d29a621db1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -278,9 +278,6 @@ struct stmmac_safety_stats {
 #define FLOW_TX		2
 #define FLOW_AUTO	(FLOW_TX | FLOW_RX)
 
-/* PCS defines */
-#define STMMAC_PCS_SGMII	(1 << 1)
-
 #define SF_DMA_MODE 1		/* DMA STORE-AND-FORWARD Operation Mode */
 
 /* DMA HW feature register fields */
@@ -632,7 +629,6 @@ struct mac_device_info {
 	unsigned int unicast_filter_entries;
 	unsigned int mcast_bits_log2;
 	unsigned int rx_csum;
-	unsigned int pcs;
 	unsigned int num_vlan;
 	u32 vlan_filter[32];
 	bool vlan_fail_q_en;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f0160ff54a59..7b5ba672cc0e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -946,11 +946,8 @@ static struct phylink_pcs *stmmac_mac_select_pcs(struct phylink_config *config,
 			return pcs;
 	}
 
-	/* The PCS control register is only relevant for SGMII, TBI and RTBI
-	 * modes. We no longer support TBI or RTBI, so only configure this
-	 * register when operating in SGMII mode with the integrated PCS.
-	 */
-	if (priv->hw->pcs & STMMAC_PCS_SGMII && priv->integrated_pcs)
+	if (priv->integrated_pcs &&
+	    test_bit(interface, priv->integrated_pcs->pcs.supported_interfaces))
 		return &priv->integrated_pcs->pcs;
 
 	return NULL;
@@ -1209,7 +1206,6 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
 
 	if (priv->dma_cap.pcs && interface == PHY_INTERFACE_MODE_SGMII) {
 		netdev_dbg(priv->dev, "PCS SGMII support enabled\n");
-		priv->hw->pcs = STMMAC_PCS_SGMII;
 
 		switch (speed) {
 		case SPEED_10:
-- 
2.47.3