[RFC PATCH 4/5] net: dsa: implement vtu_getnext and vtu_loadpurge for mv88e6250

[Rasmus Villemoes <rasmus.villemoes@prevas.dk>]

These are almost identical to the 6185 variants, but have fewer bits
for the FID.

Bit 10 of the VTU_OP register (offset 0x05) is the VidPolicy bit,
which one should probably preserve in mv88e6xxx_g1_vtu_op(), instead
of always writing a 0. However, on the 6352 family, that bit is
located at bit 12 in the VTU FID register (offset 0x02), and is always
unconditionally cleared by the mv88e6xxx_g1_vtu_fid_write()
function.

Since nothing in the existing driver seems to know or care about that
bit, it seems reasonable to not add the boilerplate to preserve it for
the 6250 (which would require adding a chip-specific vtu_op function,
or adding chip-quirks to the existing one).

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
---
 drivers/net/dsa/mv88e6xxx/global1.h     |  4 ++
 drivers/net/dsa/mv88e6xxx/global1_vtu.c | 58 +++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/global1.h b/drivers/net/dsa/mv88e6xxx/global1.h
index bef01331266f..b205b0bba158 100644
--- a/drivers/net/dsa/mv88e6xxx/global1.h
+++ b/drivers/net/dsa/mv88e6xxx/global1.h
@@ -305,6 +305,10 @@ int mv88e6185_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 			     struct mv88e6xxx_vtu_entry *entry);
 int mv88e6185_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
 			       struct mv88e6xxx_vtu_entry *entry);
+int mv88e6250_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
+			     struct mv88e6xxx_vtu_entry *entry);
+int mv88e6250_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
+			       struct mv88e6xxx_vtu_entry *entry);
 int mv88e6352_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 			     struct mv88e6xxx_vtu_entry *entry);
 int mv88e6352_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
diff --git a/drivers/net/dsa/mv88e6xxx/global1_vtu.c b/drivers/net/dsa/mv88e6xxx/global1_vtu.c
index 058326924f3e..a8ef268c32cb 100644
--- a/drivers/net/dsa/mv88e6xxx/global1_vtu.c
+++ b/drivers/net/dsa/mv88e6xxx/global1_vtu.c
@@ -307,6 +307,35 @@ static int mv88e6xxx_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 	return mv88e6xxx_g1_vtu_vid_read(chip, entry);
 }
 
+int mv88e6250_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
+			     struct mv88e6xxx_vtu_entry *entry)
+{
+	u16 val;
+	int err;
+
+	err = mv88e6xxx_g1_vtu_getnext(chip, entry);
+	if (err)
+		return err;
+
+	if (entry->valid) {
+		err = mv88e6185_g1_vtu_data_read(chip, entry);
+		if (err)
+			return err;
+
+		/* VTU DBNum[3:0] are located in VTU Operation 3:0
+		 * VTU DBNum[5:4] are located in VTU Operation 9:8
+		 */
+		err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_OP, &val);
+		if (err)
+			return err;
+
+		entry->fid = val & 0x000f;
+		entry->fid |= (val & 0x0300) >> 4;
+	}
+
+	return 0;
+}
+
 int mv88e6185_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 			     struct mv88e6xxx_vtu_entry *entry)
 {
@@ -396,6 +425,35 @@ int mv88e6390_g1_vtu_getnext(struct mv88e6xxx_chip *chip,
 	return 0;
 }
 
+int mv88e6250_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
+			       struct mv88e6xxx_vtu_entry *entry)
+{
+	u16 op = MV88E6XXX_G1_VTU_OP_VTU_LOAD_PURGE;
+	int err;
+
+	err = mv88e6xxx_g1_vtu_op_wait(chip);
+	if (err)
+		return err;
+
+	err = mv88e6xxx_g1_vtu_vid_write(chip, entry);
+	if (err)
+		return err;
+
+	if (entry->valid) {
+		err = mv88e6185_g1_vtu_data_write(chip, entry);
+		if (err)
+			return err;
+
+		/* VTU DBNum[3:0] are located in VTU Operation 3:0
+		 * VTU DBNum[5:4] are located in VTU Operation 9:8
+		 */
+		op |= entry->fid & 0x000f;
+		op |= (entry->fid & 0x0030) << 8;
+	}
+
+	return mv88e6xxx_g1_vtu_op(chip, op);
+}
+
 int mv88e6185_g1_vtu_loadpurge(struct mv88e6xxx_chip *chip,
 			       struct mv88e6xxx_vtu_entry *entry)
 {
-- 
2.20.1