[PATCH 5.15 087/207] net: dsa: mv88e6xxx: Save power by disabling SerDes trasmitter and receiver

Greg Kroah-Hartman
2021-12-06T15:43:03Z

From: Marek Behún <kabel@kernel.org>

commit 7527d66260ac0c603c6baca5146748061fcddbd6 upstream.

Save power on 88E6393X by disabling SerDes receiver and transmitter
after SerDes is SerDes is disabled.

Signed-off-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org # de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/dsa/mv88e6xxx/serdes.c | 46 +++++++++++++++++++++++++++++++++----
drivers/net/dsa/mv88e6xxx/serdes.h | 3 ++
2 files changed, 45 insertions(+), 4 deletions(-)

--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -1271,6 +1271,28 @@ void mv88e6390_serdes_get_regs(struct mv
}
}

+static int mv88e6393x_serdes_power_lane(struct mv88e6xxx_chip *chip, int lane,
+ bool on)
+{
+ u16 reg;
+ int err;
+
+ err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
+ MV88E6393X_SERDES_CTRL1, &reg);
+ if (err)
+ return err;
+
+ if (on)
+ reg &= ~(MV88E6393X_SERDES_CTRL1_TX_PDOWN |
+ MV88E6393X_SERDES_CTRL1_RX_PDOWN);
+ else
+ reg |= MV88E6393X_SERDES_CTRL1_TX_PDOWN |
+ MV88E6393X_SERDES_CTRL1_RX_PDOWN;
+
+ return mv88e6390_serdes_write(chip, lane, MDIO_MMD_PHYXS,
+ MV88E6393X_SERDES_CTRL1, reg);
+}
+
static int mv88e6393x_serdes_erratum_4_6(struct mv88e6xxx_chip *chip, int lane)
{
u16 reg;
@@ -1297,7 +1319,11 @@ static int mv88e6393x_serdes_erratum_4_6
if (err)
return err;

- return mv88e6390_serdes_power_sgmii(chip, lane, false);
+ err = mv88e6390_serdes_power_sgmii(chip, lane, false);
+ if (err)
+ return err;
+
+ return mv88e6393x_serdes_power_lane(chip, lane, false);
}

int mv88e6393x_serdes_setup_errata(struct mv88e6xxx_chip *chip)
@@ -1362,17 +1388,29 @@ int mv88e6393x_serdes_power(struct mv88e
err = mv88e6393x_serdes_erratum_4_8(chip, lane);
if (err)
return err;
+
+ err = mv88e6393x_serdes_power_lane(chip, lane, true);
+ if (err)
+ return err;
}

switch (cmode) {
case MV88E6XXX_PORT_STS_CMODE_SGMII:
case MV88E6XXX_PORT_STS_CMODE_1000BASEX:
case MV88E6XXX_PORT_STS_CMODE_2500BASEX:
- return mv88e6390_serdes_power_sgmii(chip, lane, on);
+ err = mv88e6390_serdes_power_sgmii(chip, lane, on);
+ break;
case MV88E6393X_PORT_STS_CMODE_5GBASER:
case MV88E6393X_PORT_STS_CMODE_10GBASER:
- return mv88e6390_serdes_power_10g(chip, lane, on);
+ err = mv88e6390_serdes_power_10g(chip, lane, on);
+ break;
}

- return 0;
+ if (err)
+ return err;
+
+ if (!on)
+ err = mv88e6393x_serdes_power_lane(chip, lane, false);
+
+ return err;
}
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -93,6 +93,9 @@
#define MV88E6393X_SERDES_POC_PCS_MASK 0x0007
#define MV88E6393X_SERDES_POC_RESET BIT(15)
#define MV88E6393X_SERDES_POC_PDOWN BIT(5)
+#define MV88E6393X_SERDES_CTRL1 0xf003
+#define MV88E6393X_SERDES_CTRL1_TX_PDOWN BIT(9)
+#define MV88E6393X_SERDES_CTRL1_RX_PDOWN BIT(8)

#define MV88E6393X_ERRATA_4_8_REG 0xF074
#define MV88E6393X_ERRATA_4_8_BIT BIT(14)