net: dsa: microchip: Setup fiber ports for KSZ8463

The fiber ports in KSZ8463 cannot be detected internally, so it requires
specifying that condition in the device tree.  Like the one used in
Micrel PHY the port link can only be read and there is no write to the
PHY.  The driver programs registers to operate fiber ports correctly.

Signed-off-by: Tristram Ha <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: triha2work

drivers/net/dsa/microchip/ksz8.c

@@ -1714,6 +1714,7 @@ void ksz8_config_cpu_port(struct dsa_switch *ds)
 	const u32 *masks;
 	const u16 *regs;
 	u8 remote;
+	u8 fiber_ports = 0;
 	int i;
 
 	masks = dev->info->masks;
@@ -1744,6 +1745,21 @@ void ksz8_config_cpu_port(struct dsa_switch *ds)
 		else
 			ksz_port_cfg(dev, i, regs[P_STP_CTRL],
 				     PORT_FORCE_FLOW_CTRL, false);
+		if (p->fiber)
+			fiber_ports |= (1 << i);
+	}
+	if (ksz_is_ksz8463(dev)) {
+		/* Setup fiber ports. */
+		if (fiber_ports) {
+			fiber_ports &= 3;
+			regmap_update_bits(ksz_regmap_16(dev),
+					   KSZ8463_REG_CFG_CTRL,
+					   fiber_ports << PORT_COPPER_MODE_S,
+					   0);
+			regmap_update_bits(ksz_regmap_16(dev),
+					   KSZ8463_REG_DSP_CTRL_6,
+					   COPPER_RECEIVE_ADJUSTMENT, 0);
+		}
 	}
 }
 

drivers/net/dsa/microchip/ksz_common.c

@@ -5439,6 +5439,9 @@ int ksz_switch_register(struct ksz_device *dev)
 						&dev->ports[port_num].interface);
 
 				ksz_parse_rgmii_delay(dev, port_num, port);
+				dev->ports[port_num].fiber =
+					of_property_read_bool(port,
+							      "micrel,fiber-mode");
 			}
 			of_node_put(ports);
 		}