sfc: Use lm87 and lm90 drivers for board temperature/power monitoring

Add board monitoring to periodic work whenever link is down.
For SFE4001, report when a fault has caused the PHY to turn off.
For SFE4002, switch XFP PHY into low-power state in case of a fault.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/sfc/xfp_phy.c b/drivers/net/sfc/xfp_phy.c
index 276151d..91f0246 100644
--- a/drivers/net/sfc/xfp_phy.c
+++ b/drivers/net/sfc/xfp_phy.c
@@ -128,6 +128,15 @@
 	if (link_up != efx->link_up)
 		falcon_xmac_sim_phy_event(efx);
 
+	rc = efx->board_info.monitor(efx);
+	if (rc) {
+		struct xfp_phy_data *phy_data = efx->phy_data;
+		EFX_ERR(efx, "XFP sensor alert; putting PHY into low power\n");
+		efx->phy_mode |= PHY_MODE_LOW_POWER;
+		mdio_clause45_set_mmds_lpower(efx, 1, XFP_REQUIRED_DEVS);
+		phy_data->phy_mode |= PHY_MODE_LOW_POWER;
+	}
+
 	return rc;
 }