net: macb: add support for reporting SGMII inband link status

This makes it possible to use in-band autonegotiation with
SGMII.

If using a device tree, this can be done by adding the managed =
"in-band-status" property to the gem node.

Signed-off-by: Charles Perry <charles.perry@microchip.com>
Link: https://patch.msgid.link/20260224202854.112813-3-charles.perry@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index fc26e70..8c192d6 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -560,7 +560,12 @@ static int macb_usx_pcs_config(struct phylink_pcs *pcs,
 static void macb_pcs_get_state(struct phylink_pcs *pcs, unsigned int neg_mode,
                               struct phylink_link_state *state)
 {
-       state->link = 0;
+       struct macb *bp = container_of(pcs, struct macb, phylink_sgmii_pcs);
+       u16 bmsr, lpa;
+
+       bmsr = gem_readl(bp, PCSSTS);
+       lpa = gem_readl(bp, PCSANLPBASE);
+       phylink_mii_c22_pcs_decode_state(state, neg_mode, bmsr, lpa);
 }
 
 static void macb_pcs_an_restart(struct phylink_pcs *pcs)