[PATCH net-next 2/2] net: stmmac: dwmac-socfpga: Set interface modes from Lynx PCS as supported

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

On Socfpga, the dwmac controller uses a variation of the Lynx PCS to get
additional support for SGMII and 1000BaseX. The switch between these
modes may occur at runtime (e.g. when the interface is wired to an SFP
cage). In such case, phylink will validate the newly selected interface
between the MAC and SFP based on the internal "supported_interfaces"
field.

For now in stmmac, this field is populated based on :
 - The interface specified in firmware (DT)
 - The interfaces supported by XPCS, when XPCS is in use.

In our case, the PCS in Lynx and not XPCS.

This commit makes so that the .pcs_init() implementation of
dwmac-socfpga populates the supported_interface when the Lynx PCS was
successfully initialized.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 8c7b82d29fd1..ff9a30afd7e1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -425,6 +425,17 @@ static int socfpga_dwmac_pcs_init(struct stmmac_priv *priv)
 		return PTR_ERR(pcs);
 
 	priv->hw->phylink_pcs = pcs;
+
+	/* Having a Lynx PCS means we can use SGMII and 1000BaseX. Phylink's
+	 * supported_interface is populated according to what's found in
+	 * devicetree, but as we can dynamically switch between both modes at
+	 * runtime, make sure both modes are marked as supported
+	 */
+	__set_bit(PHY_INTERFACE_MODE_1000BASEX,
+		  priv->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_SGMII,
+		  priv->phylink_config.supported_interfaces);
+
 	return 0;
 }
 
-- 
2.47.1