net: dsa: mv88e6xxx: add cap for Priority Override

Add flags and helpers to describe the presence of Priority Override
Table (POT) related registers and simplify the setup of Global 2.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -3172,6 +3172,28 @@ static int mv88e6xxx_g2_set_switch_mac(struct mv88e6xxx_chip *chip, u8 *addr)
 	return err;
 }
 
+static int mv88e6xxx_g2_pot_write(struct mv88e6xxx_chip *chip, int pointer,
+				  u8 data)
+{
+	u16 val = (pointer << 8) | (data & 0x7);
+
+	return mv88e6xxx_update(chip, REG_GLOBAL2, GLOBAL2_PRIO_OVERRIDE, val);
+}
+
+static int mv88e6xxx_g2_clear_pot(struct mv88e6xxx_chip *chip)
+{
+	int i, err;
+
+	/* Clear all sixteen possible Priority Override entries */
+	for (i = 0; i < 16; i++) {
+		err = mv88e6xxx_g2_pot_write(chip, i, 0);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
 static int mv88e6xxx_g2_setup(struct mv88e6xxx_chip *chip)
 {
 	u16 reg;
@@ -3229,18 +3251,12 @@ static int mv88e6xxx_g2_setup(struct mv88e6xxx_chip *chip)
 			return err;
 	}
 
-	if (mv88e6xxx_6352_family(chip) || mv88e6xxx_6351_family(chip) ||
-	    mv88e6xxx_6165_family(chip) || mv88e6xxx_6097_family(chip) ||
-	    mv88e6xxx_6320_family(chip)) {
+	if (mv88e6xxx_has(chip, MV88E6XXX_FLAG_G2_POT)) {
 		/* Clear the priority override table. */
-		for (i = 0; i < 16; i++) {
-			err = _mv88e6xxx_reg_write(chip, REG_GLOBAL2,
-						   GLOBAL2_PRIO_OVERRIDE,
-						   0x8000 | (i << 8));
+		err = mv88e6xxx_g2_clear_pot(chip);
 		if (err)
 			return err;
 	}
-	}
 
 	if (mv88e6xxx_6352_family(chip) || mv88e6xxx_6351_family(chip) ||
 	    mv88e6xxx_6165_family(chip) || mv88e6xxx_6097_family(chip) ||

drivers/net/dsa/mv88e6xxx/mv88e6xxx.h

@@ -396,6 +396,7 @@ enum mv88e6xxx_cap {
 	MV88E6XXX_CAP_G2_PVT_ADDR,	/* (0x0b) Cross Chip Port VLAN Addr */
 	MV88E6XXX_CAP_G2_PVT_DATA,	/* (0x0c) Cross Chip Port VLAN Data */
 	MV88E6XXX_CAP_G2_SWITCH_MAC,	/* (0x0d) Switch MAC/WoL/WoF */
+	MV88E6XXX_CAP_G2_POT,		/* (0x0f) Priority Override Table */
 
 	/* Multi-chip Addressing Mode.
 	 * Some chips require an indirect SMI access when their SMI device
@@ -442,6 +443,7 @@ enum mv88e6xxx_cap {
 #define MV88E6XXX_FLAG_G2_PVT_ADDR	BIT(MV88E6XXX_CAP_G2_PVT_ADDR)
 #define MV88E6XXX_FLAG_G2_PVT_DATA	BIT(MV88E6XXX_CAP_G2_PVT_DATA)
 #define MV88E6XXX_FLAG_G2_SWITCH_MAC	BIT(MV88E6XXX_CAP_G2_SWITCH_MAC)
+#define MV88E6XXX_FLAG_G2_POT		BIT(MV88E6XXX_CAP_G2_POT)
 #define MV88E6XXX_FLAG_MULTI_CHIP	BIT(MV88E6XXX_CAP_MULTI_CHIP)
 #define MV88E6XXX_FLAG_PPU		BIT(MV88E6XXX_CAP_PPU)
 #define MV88E6XXX_FLAG_PPU_ACTIVE	BIT(MV88E6XXX_CAP_PPU_ACTIVE)
@@ -467,6 +469,7 @@ enum mv88e6xxx_cap {
 	(MV88E6XXX_FLAG_GLOBAL2 |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_2X |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_0X |	\
+	 MV88E6XXX_FLAG_G2_POT |	\
 	 MV88E6XXX_FLAG_MULTI_CHIP |	\
 	 MV88E6XXX_FLAG_PPU |		\
 	 MV88E6XXX_FLAG_STU |		\
@@ -478,6 +481,7 @@ enum mv88e6xxx_cap {
 	 MV88E6XXX_FLAG_G2_MGMT_EN_2X |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_0X |	\
 	 MV88E6XXX_FLAG_G2_SWITCH_MAC |	\
+	 MV88E6XXX_FLAG_G2_POT |	\
 	 MV88E6XXX_FLAG_MULTI_CHIP |	\
 	 MV88E6XXX_FLAG_STU |		\
 	 MV88E6XXX_FLAG_TEMP |		\
@@ -498,6 +502,7 @@ enum mv88e6xxx_cap {
 	 MV88E6XXX_FLAG_G2_MGMT_EN_2X |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_0X |	\
 	 MV88E6XXX_FLAG_G2_SWITCH_MAC |	\
+	 MV88E6XXX_FLAG_G2_POT |	\
 	 MV88E6XXX_FLAG_MULTI_CHIP |	\
 	 MV88E6XXX_FLAG_PPU_ACTIVE |	\
 	 MV88E6XXX_FLAG_SMI_PHY |	\
@@ -511,6 +516,7 @@ enum mv88e6xxx_cap {
 	 MV88E6XXX_FLAG_G2_MGMT_EN_2X |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_0X |	\
 	 MV88E6XXX_FLAG_G2_SWITCH_MAC |	\
+	 MV88E6XXX_FLAG_G2_POT |	\
 	 MV88E6XXX_FLAG_MULTI_CHIP |	\
 	 MV88E6XXX_FLAG_PPU_ACTIVE |	\
 	 MV88E6XXX_FLAG_SMI_PHY |	\
@@ -526,6 +532,7 @@ enum mv88e6xxx_cap {
 	 MV88E6XXX_FLAG_G2_MGMT_EN_2X |	\
 	 MV88E6XXX_FLAG_G2_MGMT_EN_0X |	\
 	 MV88E6XXX_FLAG_G2_SWITCH_MAC |	\
+	 MV88E6XXX_FLAG_G2_POT |	\
 	 MV88E6XXX_FLAG_MULTI_CHIP |	\
 	 MV88E6XXX_FLAG_PPU_ACTIVE |	\
 	 MV88E6XXX_FLAG_SMI_PHY |	\