[PATCH RFC net-next v3 7/8] net: stmmac: configure SGMII AN control according to phylink

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

Provide phylink with the integrated PCS autonegotiation capabilities,
and configure the PCS's AN settings according to phylink's requested
requirements.

This may cause regressions.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 24 +++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index 5dbb8fd41099..c56765b5aea4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -32,6 +32,9 @@ static unsigned int dwmac_integrated_pcs_inband_caps(struct phylink_pcs *pcs,
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
 	unsigned int ib_caps;
 
+	if (interface == PHY_INTERFACE_MODE_SGMII)
+		return LINK_INBAND_ENABLE | LINK_INBAND_DISABLE;
+
 	if (phy_interface_mode_is_8023z(interface)) {
 		ib_caps = LINK_INBAND_DISABLE;
 
@@ -135,22 +138,29 @@ static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
 				       bool permit_pause_to_mac)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
-	bool changed = false, ane = true;
+	void __iomem *an_control = spcs->base + GMAC_AN_CTRL(0);
+	bool ane, changed = false;
+	u32 ctrl;
+
+	ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
 
 	/* Only configure the advertisement and allow AN in BASE-X mode if
 	 * the core supports TBI/RTBI. AN will be filtered out by via phylink
 	 * and the .pcs_inband_caps() method above.
 	 */
 	if (phy_interface_mode_is_8023z(interface) &&
-	    spcs->support_tbi_rtbi) {
-		ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
-
+	    spcs->support_tbi_rtbi)
 		changed = dwmac_integrated_pcs_config_aneg(spcs, interface,
 							   advertising);
-	}
 
-	dwmac_ctrl_ane(spcs->base, 0, ane,
-		       spcs->priv->hw->reverse_sgmii_enable);
+	ctrl = readl(an_control) & ~(GMAC_AN_CTRL_ANE | GMAC_AN_CTRL_SGMRAL);
+	if (spcs->priv->hw->reverse_sgmii_enable)
+		ctrl |= GMAC_AN_CTRL_SGMRAL | GMAC_AN_CTRL_ANE;
+	else if (ane)
+		ctrl |= GMAC_AN_CTRL_ANE;
+	else
+		ctrl |= GMAC_AN_CTRL_SGMRAL;
+	writel(ctrl, an_control);
 
 	return changed;
 }
-- 
2.47.3