net: dsa: microchip: allow to pass return values for PHY read/write accesses

PHY access may end with errors on different levels. So, allow to forward
return values where possible.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz8.h

@@ -17,8 +17,8 @@ u32 ksz8_get_port_addr(int port, int offset);
 void ksz8_cfg_port_member(struct ksz_device *dev, int port, u8 member);
 void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port);
 void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port);
-void ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val);
-void ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val);
+int ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val);
+int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val);
 int ksz8_r_dyn_mac_table(struct ksz_device *dev, u16 addr, u8 *mac_addr,
 			 u8 *fid, u8 *src_port, u8 *timestamp, u16 *entries);
 int ksz8_r_sta_mac_table(struct ksz_device *dev, u16 addr,

drivers/net/dsa/microchip/ksz8795.c

@@ -552,7 +552,7 @@ static void ksz8_w_vlan_table(struct ksz_device *dev, u16 vid, u16 vlan)
 	ksz8_w_table(dev, TABLE_VLAN, addr, buf);
 }
 
-void ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val)
+int ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val)
 {
 	u8 restart, speed, ctrl, link;
 	int processed = true;
@@ -674,9 +674,11 @@ void ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val)
 	}
 	if (processed)
 		*val = data;
+
+	return 0;
 }
 
-void ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
+int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
 {
 	u8 restart, speed, ctrl, data;
 	const u16 *regs;
@@ -787,6 +789,8 @@ void ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
 	default:
 		break;
 	}
+
+	return 0;
 }
 
 void ksz8_cfg_port_member(struct ksz_device *dev, int port, u8 member)

drivers/net/dsa/microchip/ksz9477.c

@@ -274,7 +274,7 @@ static void ksz9477_r_phy_quirks(struct ksz_device *dev, u16 addr, u16 reg,
 		*data &= ~(BMSR_ESTATEN | BMSR_ERCAP);
 }
 
-void ksz9477_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
+int ksz9477_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
 {
 	u16 val = 0xffff;
 
@@ -322,19 +322,23 @@ void ksz9477_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
 	}
 
 	*data = val;
+
+	return 0;
 }
 
-void ksz9477_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
+int ksz9477_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
 {
 	/* No real PHY after this. */
 	if (addr >= dev->phy_port_cnt)
-		return;
+		return 0;
 
 	/* No gigabit support.  Do not write to this register. */
 	if (!dev->info->gbit_capable[addr] && reg == MII_CTRL1000)
-		return;
+		return 0;
 
 	ksz_pwrite16(dev, addr, 0x100 + (reg << 1), val);
+
+	return 0;
 }
 
 void ksz9477_cfg_port_member(struct ksz_device *dev, int port, u8 member)

drivers/net/dsa/microchip/ksz9477.h

@@ -16,8 +16,8 @@ u32 ksz9477_get_port_addr(int port, int offset);
 void ksz9477_cfg_port_member(struct ksz_device *dev, int port, u8 member);
 void ksz9477_flush_dyn_mac_table(struct ksz_device *dev, int port);
 void ksz9477_port_setup(struct ksz_device *dev, int port, bool cpu_port);
-void ksz9477_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data);
-void ksz9477_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val);
+int ksz9477_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data);
+int ksz9477_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val);
 void ksz9477_r_mib_cnt(struct ksz_device *dev, int port, u16 addr, u64 *cnt);
 void ksz9477_r_mib_pkt(struct ksz_device *dev, int port, u16 addr,
 		       u64 *dropped, u64 *cnt);

drivers/net/dsa/microchip/ksz_common.c

@@ -1132,8 +1132,11 @@ static int ksz_phy_read16(struct dsa_switch *ds, int addr, int reg)
 {
 	struct ksz_device *dev = ds->priv;
 	u16 val = 0xffff;
+	int ret;
 
-	dev->dev_ops->r_phy(dev, addr, reg, &val);
+	ret = dev->dev_ops->r_phy(dev, addr, reg, &val);
+	if (ret)
+		return ret;
 
 	return val;
 }
@@ -1141,8 +1144,11 @@ static int ksz_phy_read16(struct dsa_switch *ds, int addr, int reg)
 static int ksz_phy_write16(struct dsa_switch *ds, int addr, int reg, u16 val)
 {
 	struct ksz_device *dev = ds->priv;
+	int ret;
 
-	dev->dev_ops->w_phy(dev, addr, reg, val);
+	ret = dev->dev_ops->w_phy(dev, addr, reg, val);
+	if (ret)
+		return ret;
 
 	return 0;
 }

drivers/net/dsa/microchip/ksz_common.h

@@ -262,8 +262,8 @@ struct ksz_dev_ops {
 	void (*flush_dyn_mac_table)(struct ksz_device *dev, int port);
 	void (*port_cleanup)(struct ksz_device *dev, int port);
 	void (*port_setup)(struct ksz_device *dev, int port, bool cpu_port);
-	void (*r_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 *val);
-	void (*w_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 val);
+	int (*r_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 *val);
+	int (*w_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 val);
 	void (*r_mib_cnt)(struct ksz_device *dev, int port, u16 addr,
 			  u64 *cnt);
 	void (*r_mib_pkt)(struct ksz_device *dev, int port, u16 addr,

drivers/net/dsa/microchip/lan937x.h

@@ -12,8 +12,8 @@ void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port);
 void lan937x_config_cpu_port(struct dsa_switch *ds);
 int lan937x_switch_init(struct ksz_device *dev);
 void lan937x_switch_exit(struct ksz_device *dev);
-void lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data);
-void lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val);
+int lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data);
+int lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val);
 int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu);
 void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
 			      struct phylink_config *config);

drivers/net/dsa/microchip/lan937x_main.c

@@ -128,14 +128,14 @@ static int lan937x_internal_phy_read(struct ksz_device *dev, int addr, int reg,
 	return ksz_read16(dev, REG_VPHY_IND_DATA__2, val);
 }
 
-void lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
+int lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
 {
-	lan937x_internal_phy_read(dev, addr, reg, data);
+	return lan937x_internal_phy_read(dev, addr, reg, data);
 }
 
-void lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
+int lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
 {
-	lan937x_internal_phy_write(dev, addr, reg, val);
+	return lan937x_internal_phy_write(dev, addr, reg, val);
 }
 
 static int lan937x_sw_mdio_read(struct mii_bus *bus, int addr, int regnum)