[PATCH net-next v2 2/2] mv88e6xxx: Add SERDES Support for mv88e6321

From: Fidan Aliyeva

Date: Thu Apr 30 2026 - 08:53:11 EST


Add serdes and pcs_ops functions for mv88e6321. In mv88e6321
2 ports support serdes functionality; port 0 and port 1. These ports are
serdes-only ports.

Changes:

1. Add a function support to return the lane address for the port based on
cmode. Once that in place, reuse mv88e6352's serdes_get_regs_len and
pcs_init functions for mv88e6321.
2. Add mv88e6321_serdes_get_regs function by reusing
mv88e6352_serdes_get_regs_from_lane

Tested on mv88e6321 switch port 0.
Builds were done with allyesconfig and allmodconfig W=1.

Co-developed-by: Thomas Eckerman <thomas.eckerman.ext@xxxxxxxxxxxx>
Signed-off-by: Thomas Eckerman <thomas.eckerman.ext@xxxxxxxxxxxx>
Signed-off-by: Fidan Aliyeva <fidan.aliyeva.ext@xxxxxxxxxxxx>
---
drivers/net/dsa/mv88e6xxx/chip.c | 4 ++++
drivers/net/dsa/mv88e6xxx/serdes.c | 29 +++++++++++++++++++++++++++++
drivers/net/dsa/mv88e6xxx/serdes.h | 4 ++++
3 files changed, 37 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 15a8028a02a8..c1f7fa21d964 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -5259,10 +5259,14 @@ static const struct mv88e6xxx_ops mv88e6321_ops = {
.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
.stu_getnext = mv88e6352_g1_stu_getnext,
.stu_loadpurge = mv88e6352_g1_stu_loadpurge,
+ .serdes_get_lane = mv88e6321_serdes_get_lane,
+ .serdes_get_regs_len = mv88e6352_serdes_get_regs_len,
+ .serdes_get_regs = mv88e6321_serdes_get_regs,
.gpio_ops = &mv88e6352_gpio_ops,
.avb_ops = &mv88e6352_avb_ops,
.ptp_ops = &mv88e6352_ptp_ops,
.phylink_get_caps = mv88e632x_phylink_get_caps,
+ .pcs_ops = &mv88e6352_pcs_ops,
};

static const struct mv88e6xxx_ops mv88e6341_ops = {
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 273c3b169f65..3f8c178cf843 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -249,6 +249,35 @@ void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
mv88e6352_serdes_get_regs_from_lane(chip, MV88E6352_ADDR_SERDES, _p);
}

+int mv88e6321_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
+{
+ int lane = -ENODEV;
+ u8 cmode;
+
+ if (port != 0 && port != 1)
+ return lane;
+
+ cmode = chip->ports[port].cmode;
+
+ if (cmode == MV88E6XXX_PORT_STS_CMODE_100BASEX ||
+ cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
+ cmode == MV88E6XXX_PORT_STS_CMODE_SGMII)
+ lane = port + MV88E6321_PORT0_LANE;
+
+ return lane;
+}
+
+void mv88e6321_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
+{
+ int lane;
+
+ lane = mv88e6xxx_serdes_get_lane(chip, port);
+ if (lane < 0)
+ return;
+
+ mv88e6352_serdes_get_regs_from_lane(chip, lane, _p);
+}
+
int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
{
u8 cmode = chip->ports[port].cmode;
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index 21e050b328cc..c11ea2118efc 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -14,6 +14,8 @@

struct phylink_link_state;

+#define MV88E6321_PORT0_LANE 0x0c
+
#define MV88E6352_ADDR_SERDES 0x0f
#define MV88E6352_SERDES_PAGE_FIBER 0x01
#define MV88E6352_SERDES_IRQ 0x0b
@@ -114,6 +116,7 @@ struct phylink_link_state;
int mv88e6xxx_pcs_decode_state(struct device *dev, u16 bmsr, u16 lpa,
u16 status, struct phylink_link_state *state);

+int mv88e6321_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
int mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
int mv88e6352_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
int mv88e6390_serdes_get_lane(struct mv88e6xxx_chip *chip, int port);
@@ -134,6 +137,7 @@ int mv88e6390_serdes_get_strings(struct mv88e6xxx_chip *chip, int port,
size_t mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
uint64_t *data);

+void mv88e6321_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
int mv88e6352_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
int mv88e6390_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
--
2.36.0