net: dsa: mv88e6xxx: clarify SMI PHY functions

Marvell chips with an SMI PHY access in Global 2 registers handle both
Clause 22 and Clause 45 of IEEE 802.3.

The 88E6390 family has addition bits to target the internal or external
PHYs connected to the device, and a Setup function in addition to the
default (register) Access function.

Prefix the SMI PHY Command and Data registers macros, implement clear
helpers for Clause 22 and 44 Access functions, rename variable to match
the SMI and switch vocabulary (device and register addresses for Clause
22 and port and device class for Clause 45.)

Finally do not use complex macros but simple 16-bit mask to document the
registers organization.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 118 insertions, 82 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/global2.c b/drivers/net/dsa/mv88e6xxx/global2.c
index baa86b1abad3..f20a60af35cb 100644
--- a/drivers/net/dsa/mv88e6xxx/global2.c
+++ b/drivers/net/dsa/mv88e6xxx/global2.c
@@ -13,6 +13,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/bitfield.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 
@@ -541,171 +542,206 @@ int mv88e6xxx_g2_set_eeprom16(struct mv88e6xxx_chip *chip,
 
 static int mv88e6xxx_g2_smi_phy_wait(struct mv88e6xxx_chip *chip)
 {
-	return mv88e6xxx_g2_wait(chip, GLOBAL2_SMI_PHY_CMD,
-				 GLOBAL2_SMI_PHY_CMD_BUSY);
+	return mv88e6xxx_g2_wait(chip, MV88E6XXX_G2_SMI_PHY_CMD,
+				 MV88E6XXX_G2_SMI_PHY_CMD_BUSY);
 }
 
 static int mv88e6xxx_g2_smi_phy_cmd(struct mv88e6xxx_chip *chip, u16 cmd)
 {
 	int err;
 
-	err = mv88e6xxx_g2_write(chip, GLOBAL2_SMI_PHY_CMD, cmd);
+	err = mv88e6xxx_g2_write(chip, MV88E6XXX_G2_SMI_PHY_CMD,
+				 MV88E6XXX_G2_SMI_PHY_CMD_BUSY | cmd);
 	if (err)
 		return err;
 
 	return mv88e6xxx_g2_smi_phy_wait(chip);
 }
 
-static int mv88e6xxx_g2_smi_phy_write_addr(struct mv88e6xxx_chip *chip,
-					   int addr, int device, int reg,
-					   bool external)
+static int mv88e6xxx_g2_smi_phy_access(struct mv88e6xxx_chip *chip,
+				       bool external, bool c45, u16 op, int dev,
+				       int reg)
 {
-	int cmd = SMI_CMD_OP_45_WRITE_ADDR | (addr << 5) | device;
-	int err;
+	u16 cmd = op;
 
 	if (external)
-		cmd |= GLOBAL2_SMI_PHY_CMD_EXTERNAL;
+		cmd |= MV88E6390_G2_SMI_PHY_CMD_FUNC_EXTERNAL;
+	else
+		cmd |= MV88E6390_G2_SMI_PHY_CMD_FUNC_INTERNAL; /* empty mask */
 
-	err = mv88e6xxx_g2_smi_phy_wait(chip);
-	if (err)
-		return err;
+	if (c45)
+		cmd |= MV88E6XXX_G2_SMI_PHY_CMD_MODE_45; /* empty mask */
+	else
+		cmd |= MV88E6XXX_G2_SMI_PHY_CMD_MODE_22;
 
-	err = mv88e6xxx_g2_write(chip, GLOBAL2_SMI_PHY_DATA, reg);
-	if (err)
-		return err;
+	dev <<= __bf_shf(MV88E6XXX_G2_SMI_PHY_CMD_DEV_ADDR_MASK);
+	cmd |= dev & MV88E6XXX_G2_SMI_PHY_CMD_DEV_ADDR_MASK;
+	cmd |= reg & MV88E6XXX_G2_SMI_PHY_CMD_REG_ADDR_MASK;
 
 	return mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
 }
 
-static int mv88e6xxx_g2_smi_phy_read_c45(struct mv88e6xxx_chip *chip,
-					 int addr, int reg_c45, u16 *val,
-					 bool external)
+static int mv88e6xxx_g2_smi_phy_access_c22(struct mv88e6xxx_chip *chip,
+					   bool external, u16 op, int dev,
+					   int reg)
+{
+	return mv88e6xxx_g2_smi_phy_access(chip, external, false, op, dev, reg);
+}
+
+/* IEEE 802.3 Clause 22 Read Data Register */
+static int mv88e6xxx_g2_smi_phy_read_data_c22(struct mv88e6xxx_chip *chip,
+					      bool external, int dev, int reg,
+					      u16 *data)
 {
-	int device = (reg_c45 >> 16) & 0x1f;
-	int reg = reg_c45 & 0xffff;
+	u16 op = MV88E6XXX_G2_SMI_PHY_CMD_OP_22_READ_DATA;
 	int err;
-	u16 cmd;
 
-	err = mv88e6xxx_g2_smi_phy_write_addr(chip, addr, device, reg,
-					      external);
+	err = mv88e6xxx_g2_smi_phy_wait(chip);
+	if (err)
+		return err;
+
+	err = mv88e6xxx_g2_smi_phy_access_c22(chip, external, op, dev, reg);
 	if (err)
 		return err;
 
-	cmd = GLOBAL2_SMI_PHY_CMD_OP_45_READ_DATA | (addr << 5) | device;
+	return mv88e6xxx_g2_read(chip, MV88E6XXX_G2_SMI_PHY_DATA, data);
+}
 
-	if (external)
-		cmd |= GLOBAL2_SMI_PHY_CMD_EXTERNAL;
+/* IEEE 802.3 Clause 22 Write Data Register */
+static int mv88e6xxx_g2_smi_phy_write_data_c22(struct mv88e6xxx_chip *chip,
+					       bool external, int dev, int reg,
+					       u16 data)
+{
+	u16 op = MV88E6XXX_G2_SMI_PHY_CMD_OP_22_WRITE_DATA;
+	int err;
 
-	err = mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
+	err = mv88e6xxx_g2_smi_phy_wait(chip);
 	if (err)
 		return err;
 
-	err = mv88e6xxx_g2_read(chip, GLOBAL2_SMI_PHY_DATA, val);
+	err = mv88e6xxx_g2_write(chip, MV88E6XXX_G2_SMI_PHY_DATA, data);
 	if (err)
 		return err;
 
-	err = *val;
+	return mv88e6xxx_g2_smi_phy_access_c22(chip, external, op, dev, reg);
+}
 
-	return 0;
+static int mv88e6xxx_g2_smi_phy_access_c45(struct mv88e6xxx_chip *chip,
+					   bool external, u16 op, int port,
+					   int dev)
+{
+	return mv88e6xxx_g2_smi_phy_access(chip, external, true, op, port, dev);
 }
 
-static int mv88e6xxx_g2_smi_phy_read_c22(struct mv88e6xxx_chip *chip,
-					 int addr, int reg, u16 *val,
-					 bool external)
+/* IEEE 802.3 Clause 45 Write Address Register */
+static int mv88e6xxx_g2_smi_phy_write_addr_c45(struct mv88e6xxx_chip *chip,
+					       bool external, int port, int dev,
+					       int addr)
 {
-	u16 cmd = GLOBAL2_SMI_PHY_CMD_OP_22_READ_DATA | (addr << 5) | reg;
+	u16 op = MV88E6XXX_G2_SMI_PHY_CMD_OP_45_WRITE_ADDR;
 	int err;
 
-	if (external)
-		cmd |= GLOBAL2_SMI_PHY_CMD_EXTERNAL;
-
 	err = mv88e6xxx_g2_smi_phy_wait(chip);
 	if (err)
 		return err;
 
-	err = mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
+	err = mv88e6xxx_g2_write(chip, MV88E6XXX_G2_SMI_PHY_DATA, addr);
 	if (err)
 		return err;
 
-	return mv88e6xxx_g2_read(chip, GLOBAL2_SMI_PHY_DATA, val);
+	return mv88e6xxx_g2_smi_phy_access_c45(chip, external, op, port, dev);
 }
 
-int mv88e6xxx_g2_smi_phy_read(struct mv88e6xxx_chip *chip,
-			      struct mii_bus *bus,
-			      int addr, int reg, u16 *val)
+/* IEEE 802.3 Clause 45 Read Data Register */
+static int mv88e6xxx_g2_smi_phy_read_data_c45(struct mv88e6xxx_chip *chip,
+					      bool external, int port, int dev,
+					      u16 *data)
 {
-	struct mv88e6xxx_mdio_bus *mdio_bus = bus->priv;
-	bool external = mdio_bus->external;
+	u16 op = MV88E6XXX_G2_SMI_PHY_CMD_OP_45_READ_DATA;
+	int err;
 
-	if (reg & MII_ADDR_C45)
-		return mv88e6xxx_g2_smi_phy_read_c45(chip, addr, reg, val,
-						     external);
-	return mv88e6xxx_g2_smi_phy_read_c22(chip, addr, reg, val, external);
+	err = mv88e6xxx_g2_smi_phy_access_c45(chip, external, op, port, dev);
+	if (err)
+		return err;
+
+	return mv88e6xxx_g2_read(chip, MV88E6XXX_G2_SMI_PHY_DATA, data);
 }
 
-static int mv88e6xxx_g2_smi_phy_write_c45(struct mv88e6xxx_chip *chip,
-					  int addr, int reg_c45, u16 val,
-					  bool external)
+static int mv88e6xxx_g2_smi_phy_read_c45(struct mv88e6xxx_chip *chip,
+					 bool external, int port, int reg,
+					 u16 *data)
 {
-	int device = (reg_c45 >> 16) & 0x1f;
-	int reg = reg_c45 & 0xffff;
+	int dev = (reg >> 16) & 0x1f;
+	int addr = reg & 0xffff;
 	int err;
-	u16 cmd;
 
-	err = mv88e6xxx_g2_smi_phy_write_addr(chip, addr, device, reg,
-					      external);
+	err = mv88e6xxx_g2_smi_phy_write_addr_c45(chip, external, port, dev,
+						  addr);
 	if (err)
 		return err;
 
-	cmd = GLOBAL2_SMI_PHY_CMD_OP_45_WRITE_DATA | (addr << 5) | device;
-
-	if (external)
-		cmd |= GLOBAL2_SMI_PHY_CMD_EXTERNAL;
+	return mv88e6xxx_g2_smi_phy_read_data_c45(chip, external, port, dev,
+						  data);
+}
 
-	err = mv88e6xxx_g2_write(chip, GLOBAL2_SMI_PHY_DATA, val);
-	if (err)
-		return err;
+/* IEEE 802.3 Clause 45 Write Data Register */
+static int mv88e6xxx_g2_smi_phy_write_data_c45(struct mv88e6xxx_chip *chip,
+					       bool external, int port, int dev,
+					       u16 data)
+{
+	u16 op = MV88E6XXX_G2_SMI_PHY_CMD_OP_45_WRITE_DATA;
+	int err;
 
-	err = mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
+	err = mv88e6xxx_g2_write(chip, MV88E6XXX_G2_SMI_PHY_DATA, data);
 	if (err)
 		return err;
 
-	return 0;
+	return mv88e6xxx_g2_smi_phy_access_c45(chip, external, op, port, dev);
 }
 
-static int mv88e6xxx_g2_smi_phy_write_c22(struct mv88e6xxx_chip *chip,
-					  int addr, int reg, u16 val,
-					  bool external)
+static int mv88e6xxx_g2_smi_phy_write_c45(struct mv88e6xxx_chip *chip,
+					  bool external, int port, int reg,
+					  u16 data)
 {
-	u16 cmd = GLOBAL2_SMI_PHY_CMD_OP_22_WRITE_DATA | (addr << 5) | reg;
+	int dev = (reg >> 16) & 0x1f;
+	int addr = reg & 0xffff;
 	int err;
 
-	if (external)
-		cmd |= GLOBAL2_SMI_PHY_CMD_EXTERNAL;
-
-	err = mv88e6xxx_g2_smi_phy_wait(chip);
+	err = mv88e6xxx_g2_smi_phy_write_addr_c45(chip, external, port, dev,
+						  addr);
 	if (err)
 		return err;
 
-	err = mv88e6xxx_g2_write(chip, GLOBAL2_SMI_PHY_DATA, val);
-	if (err)
-		return err;
+	return mv88e6xxx_g2_smi_phy_write_data_c45(chip, external, port, dev,
+						   data);
+}
 
-	return mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
+int mv88e6xxx_g2_smi_phy_read(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
+			      int addr, int reg, u16 *val)
+{
+	struct mv88e6xxx_mdio_bus *mdio_bus = bus->priv;
+	bool external = mdio_bus->external;
+
+	if (reg & MII_ADDR_C45)
+		return mv88e6xxx_g2_smi_phy_read_c45(chip, external, addr, reg,
+						     val);
+
+	return mv88e6xxx_g2_smi_phy_read_data_c22(chip, external, addr, reg,
+						  val);
 }
 
-int mv88e6xxx_g2_smi_phy_write(struct mv88e6xxx_chip *chip,
-			       struct mii_bus *bus,
+int mv88e6xxx_g2_smi_phy_write(struct mv88e6xxx_chip *chip, struct mii_bus *bus,
 			       int addr, int reg, u16 val)
 {
 	struct mv88e6xxx_mdio_bus *mdio_bus = bus->priv;
 	bool external = mdio_bus->external;
 
 	if (reg & MII_ADDR_C45)
-		return mv88e6xxx_g2_smi_phy_write_c45(chip, addr, reg, val,
-						      external);
+		return mv88e6xxx_g2_smi_phy_write_c45(chip, external, addr, reg,
+						      val);
 
-	return mv88e6xxx_g2_smi_phy_write_c22(chip, addr, reg, val, external);
+	return mv88e6xxx_g2_smi_phy_write_data_c22(chip, external, addr, reg,
+						   val);
 }
 
 static int mv88e6097_watchdog_action(struct mv88e6xxx_chip *chip, int irq)