From 926eae604403acfa27ba5b072af458e87e634a50 Mon Sep 17 00:00:00 2001 From: Holger Brunck Date: Thu, 10 Feb 2022 18:48:23 +0100 Subject: [PATCH] dsa: mv88e6xxx: make serdes SGMII/Fiber tx amplitude configurable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The mv88e6352, mv88e6240 and mv88e6176 have a serdes interface. This patch allows to configure the output swing to a desired value in the phy-handle of the port. The value which is peak to peak has to be specified in microvolts. As the chips only supports eight dedicated values we return EINVAL if the value in the DTS does not match one of these values. Signed-off-by: Holger Brunck Reviewed-by: Andrew Lunn Reviewed-by: Marek Behún Signed-off-by: David S. Miller --- drivers/net/dsa/mv88e6xxx/chip.c | 23 ++++++++++++++++++ drivers/net/dsa/mv88e6xxx/chip.h | 4 ++++ drivers/net/dsa/mv88e6xxx/serdes.c | 38 ++++++++++++++++++++++++++++++ drivers/net/dsa/mv88e6xxx/serdes.h | 5 ++++ 4 files changed, 70 insertions(+) diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 5344d0c0647e2..85527fe4fcc87 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -2987,7 +2987,10 @@ static int mv88e6xxx_setup_upstream_port(struct mv88e6xxx_chip *chip, int port) static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) { + struct device_node *phy_handle = NULL; struct dsa_switch *ds = chip->ds; + struct dsa_port *dp; + int tx_amp; int err; u16 reg; @@ -3178,6 +3181,23 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) return err; } + if (chip->info->ops->serdes_set_tx_amplitude) { + dp = dsa_to_port(ds, port); + if (dp) + phy_handle = of_parse_phandle(dp->dn, "phy-handle", 0); + + if (phy_handle && !of_property_read_u32(phy_handle, + "tx-p2p-microvolt", + &tx_amp)) + err = chip->info->ops->serdes_set_tx_amplitude(chip, + port, tx_amp); + if (phy_handle) { + of_node_put(phy_handle); + if (err) + return err; + } + } + /* Port based VLAN map: give each port the same default address * database, and allow bidirectional communication between the * CPU and DSA port(s), and the other ports. @@ -4246,6 +4266,7 @@ static const struct mv88e6xxx_ops mv88e6176_ops = { .serdes_irq_status = mv88e6352_serdes_irq_status, .serdes_get_regs_len = mv88e6352_serdes_get_regs_len, .serdes_get_regs = mv88e6352_serdes_get_regs, + .serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude, .gpio_ops = &mv88e6352_gpio_ops, .phylink_get_caps = mv88e6352_phylink_get_caps, }; @@ -4526,6 +4547,7 @@ static const struct mv88e6xxx_ops mv88e6240_ops = { .serdes_irq_status = mv88e6352_serdes_irq_status, .serdes_get_regs_len = mv88e6352_serdes_get_regs_len, .serdes_get_regs = mv88e6352_serdes_get_regs, + .serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude, .gpio_ops = &mv88e6352_gpio_ops, .avb_ops = &mv88e6352_avb_ops, .ptp_ops = &mv88e6352_ptp_ops, @@ -4932,6 +4954,7 @@ static const struct mv88e6xxx_ops mv88e6352_ops = { .serdes_get_stats = mv88e6352_serdes_get_stats, .serdes_get_regs_len = mv88e6352_serdes_get_regs_len, .serdes_get_regs = mv88e6352_serdes_get_regs, + .serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude, .phylink_get_caps = mv88e6352_phylink_get_caps, }; diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h index 12aa637779f51..30b92a2656131 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.h +++ b/drivers/net/dsa/mv88e6xxx/chip.h @@ -588,6 +588,10 @@ struct mv88e6xxx_ops { void (*serdes_get_regs)(struct mv88e6xxx_chip *chip, int port, void *_p); + /* SERDES SGMII/Fiber Output Amplitude */ + int (*serdes_set_tx_amplitude)(struct mv88e6xxx_chip *chip, int port, + int val); + /* Address Translation Unit operations */ int (*atu_get_hash)(struct mv88e6xxx_chip *chip, u8 *hash); int (*atu_set_hash)(struct mv88e6xxx_chip *chip, u8 hash); diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c index 6a177bf654ee5..7b37d45bc9fb5 100644 --- a/drivers/net/dsa/mv88e6xxx/serdes.c +++ b/drivers/net/dsa/mv88e6xxx/serdes.c @@ -1313,6 +1313,44 @@ void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p) } } +static const int mv88e6352_serdes_p2p_to_reg[] = { + /* Index of value in microvolts corresponds to the register value */ + 14000, 112000, 210000, 308000, 406000, 504000, 602000, 700000, +}; + +int mv88e6352_serdes_set_tx_amplitude(struct mv88e6xxx_chip *chip, int port, + int val) +{ + bool found = false; + u16 ctrl, reg; + int err; + int i; + + err = mv88e6352_g2_scratch_port_has_serdes(chip, port); + if (err <= 0) + return err; + + for (i = 0; i < ARRAY_SIZE(mv88e6352_serdes_p2p_to_reg); ++i) { + if (mv88e6352_serdes_p2p_to_reg[i] == val) { + reg = i; + found = true; + break; + } + } + + if (!found) + return -EINVAL; + + err = mv88e6352_serdes_read(chip, MV88E6352_SERDES_SPEC_CTRL2, &ctrl); + if (err) + return err; + + ctrl &= ~MV88E6352_SERDES_OUT_AMP_MASK; + ctrl |= reg; + + return mv88e6352_serdes_write(chip, MV88E6352_SERDES_SPEC_CTRL2, ctrl); +} + static int mv88e6393x_serdes_power_lane(struct mv88e6xxx_chip *chip, int lane, bool on) { diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h index 8dd8ed225b459..29bb4e91e2f6b 100644 --- a/drivers/net/dsa/mv88e6xxx/serdes.h +++ b/drivers/net/dsa/mv88e6xxx/serdes.h @@ -27,6 +27,8 @@ #define MV88E6352_SERDES_INT_FIBRE_ENERGY BIT(4) #define MV88E6352_SERDES_INT_STATUS 0x13 +#define MV88E6352_SERDES_SPEC_CTRL2 0x1a +#define MV88E6352_SERDES_OUT_AMP_MASK 0x0007 #define MV88E6341_PORT5_LANE 0x15 @@ -176,6 +178,9 @@ 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); void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p); +int mv88e6352_serdes_set_tx_amplitude(struct mv88e6xxx_chip *chip, int port, + int val); + /* Return the (first) SERDES lane address a port is using, -errno otherwise. */ static inline int mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)