net: dsa: mv88e6xxx: Add SERDES phydev_mac_change up for 6390

phylink wants to know when the MAC layers notices a change in the
link. For the 6390 family, this is a change in the SERDES state.

Add interrupt support for the SERDES interface used to implement
SGMII/1000Base-X/2500Base-X. This is currently limited to ports 9 and
10. Support for the 10G SERDES and other ports will be added later,
building on this basic framework.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 222 insertions, 0 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 5845cbf7f096..17752316ab10 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2337,7 +2337,12 @@ static int mv88e6xxx_port_enable(struct dsa_switch *ds, int port,
         int err;
 
         mutex_lock(&chip->reg_lock);
+
         err = mv88e6xxx_serdes_power(chip, port, true);
+
+        if (!err && chip->info->ops->serdes_irq_setup)
+                err = chip->info->ops->serdes_irq_setup(chip, port);
+
         mutex_unlock(&chip->reg_lock);
 
         return err;
@@ -2349,8 +2354,13 @@ static void mv88e6xxx_port_disable(struct dsa_switch *ds, int port,
         struct mv88e6xxx_chip *chip = ds->priv;
 
         mutex_lock(&chip->reg_lock);
+
+        if (chip->info->ops->serdes_irq_free)
+                chip->info->ops->serdes_irq_free(chip, port);
+
         if (mv88e6xxx_serdes_power(chip, port, false))
                 dev_err(chip->dev, "failed to power off SERDES\n");
+
         mutex_unlock(&chip->reg_lock);
 }
 
@@ -3225,6 +3235,8 @@ static const struct mv88e6xxx_ops mv88e6190_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .gpio_ops = &mv88e6352_gpio_ops,
         .phylink_validate = mv88e6390_phylink_validate,
 };
@@ -3265,6 +3277,8 @@ static const struct mv88e6xxx_ops mv88e6190x_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390x_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .gpio_ops = &mv88e6352_gpio_ops,
         .phylink_validate = mv88e6390x_phylink_validate,
 };
@@ -3305,6 +3319,8 @@ static const struct mv88e6xxx_ops mv88e6191_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .avb_ops = &mv88e6390_avb_ops,
         .ptp_ops = &mv88e6352_ptp_ops,
         .phylink_validate = mv88e6390_phylink_validate,
@@ -3393,6 +3409,8 @@ static const struct mv88e6xxx_ops mv88e6290_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .gpio_ops = &mv88e6352_gpio_ops,
         .avb_ops = &mv88e6390_avb_ops,
         .ptp_ops = &mv88e6352_ptp_ops,
@@ -3694,6 +3712,8 @@ static const struct mv88e6xxx_ops mv88e6390_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .gpio_ops = &mv88e6352_gpio_ops,
         .avb_ops = &mv88e6390_avb_ops,
         .ptp_ops = &mv88e6352_ptp_ops,
@@ -3739,6 +3759,8 @@ static const struct mv88e6xxx_ops mv88e6390x_ops = {
         .vtu_getnext = mv88e6390_g1_vtu_getnext,
         .vtu_loadpurge = mv88e6390_g1_vtu_loadpurge,
         .serdes_power = mv88e6390x_serdes_power,
+        .serdes_irq_setup = mv88e6390_serdes_irq_setup,
+        .serdes_irq_free = mv88e6390_serdes_irq_free,
         .gpio_ops = &mv88e6352_gpio_ops,
         .avb_ops = &mv88e6390_avb_ops,
         .ptp_ops = &mv88e6352_ptp_ops,
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 577398fe36df..f9ecb7872d32 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -200,6 +200,7 @@ struct mv88e6xxx_port {
         u64 vtu_member_violation;
         u64 vtu_miss_violation;
         u8 cmode;
+        int serdes_irq;
 };
 
 struct mv88e6xxx_chip {
@@ -434,6 +435,10 @@ struct mv88e6xxx_ops {
         /* Power on/off a SERDES interface */
         int (*serdes_power)(struct mv88e6xxx_chip *chip, int port, bool on);
 
+        /* SERDES interrupt handling */
+        int (*serdes_irq_setup)(struct mv88e6xxx_chip *chip, int port);
+        void (*serdes_irq_free)(struct mv88e6xxx_chip *chip, int port);
+
         /* Statistics from the SERDES interface */
         int (*serdes_get_sset_count)(struct mv88e6xxx_chip *chip, int port);
         int (*serdes_get_strings)(struct mv88e6xxx_chip *chip,  int port,
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 064d0bb8fe02..519346b81b87 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -11,6 +11,8 @@
  * (at your option) any later version.
  */
 
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 #include <linux/mii.h>
 
 #include "chip.h"
@@ -399,6 +401,183 @@ int mv88e6390x_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on)
         return 0;
 }
 
+static void mv88e6390_serdes_irq_link_sgmii(struct mv88e6xxx_chip *chip,
+                                            int port, int lane)
+{
+        struct dsa_switch *ds = chip->ds;
+        u16 status;
+        bool up;
+
+        mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
+                              MV88E6390_SGMII_STATUS, &status);
+
+        /* Status must be read twice in order to give the current link
+         * status. Otherwise the change in link status since the last
+         * read of the register is returned.
+         */
+        mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
+                              MV88E6390_SGMII_STATUS, &status);
+        up = status & MV88E6390_SGMII_STATUS_LINK;
+
+        dsa_port_phylink_mac_change(ds, port, up);
+}
+
+static int mv88e6390_serdes_irq_enable_sgmii(struct mv88e6xxx_chip *chip,
+                                             int lane)
+{
+        return mv88e6390_serdes_write(chip, lane, MDIO_MMD_PHYXS,
+                                      MV88E6390_SGMII_INT_ENABLE,
+                                      MV88E6390_SGMII_INT_LINK_DOWN |
+                                      MV88E6390_SGMII_INT_LINK_UP);
+}
+
+static int mv88e6390_serdes_irq_disable_sgmii(struct mv88e6xxx_chip *chip,
+                                              int lane)
+{
+        return mv88e6390_serdes_write(chip, lane, MDIO_MMD_PHYXS,
+                                      MV88E6390_SGMII_INT_ENABLE, 0);
+}
+
+int mv88e6390_serdes_irq_enable(struct mv88e6xxx_chip *chip, int port,
+                                int lane)
+{
+        u8 cmode = chip->ports[port].cmode;
+        int err = 0;
+
+        switch (cmode) {
+        case MV88E6XXX_PORT_STS_CMODE_SGMII:
+        case MV88E6XXX_PORT_STS_CMODE_1000BASE_X:
+        case MV88E6XXX_PORT_STS_CMODE_2500BASEX:
+                err = mv88e6390_serdes_irq_enable_sgmii(chip, lane);
+        }
+
+        return err;
+}
+
+int mv88e6390_serdes_irq_disable(struct mv88e6xxx_chip *chip, int port,
+                                 int lane)
+{
+        u8 cmode = chip->ports[port].cmode;
+        int err = 0;
+
+        switch (cmode) {
+        case MV88E6XXX_PORT_STS_CMODE_SGMII:
+        case MV88E6XXX_PORT_STS_CMODE_1000BASE_X:
+        case MV88E6XXX_PORT_STS_CMODE_2500BASEX:
+                err = mv88e6390_serdes_irq_disable_sgmii(chip, lane);
+        }
+
+        return err;
+}
+
+static int mv88e6390_serdes_irq_status_sgmii(struct mv88e6xxx_chip *chip,
+                                             int lane, u16 *status)
+{
+        int err;
+
+        err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
+                                    MV88E6390_SGMII_INT_STATUS, status);
+
+        return err;
+}
+
+static irqreturn_t mv88e6390_serdes_thread_fn(int irq, void *dev_id)
+{
+        struct mv88e6xxx_port *port = dev_id;
+        struct mv88e6xxx_chip *chip = port->chip;
+        irqreturn_t ret = IRQ_NONE;
+        u8 cmode = port->cmode;
+        u16 status;
+        int lane;
+        int err;
+
+        lane = mv88e6390x_serdes_get_lane(chip, port->port);
+
+        mutex_lock(&chip->reg_lock);
+
+        switch (cmode) {
+        case MV88E6XXX_PORT_STS_CMODE_SGMII:
+        case MV88E6XXX_PORT_STS_CMODE_1000BASE_X:
+        case MV88E6XXX_PORT_STS_CMODE_2500BASEX:
+                err = mv88e6390_serdes_irq_status_sgmii(chip, lane, &status);
+                if (err)
+                        goto out;
+                if (status && (MV88E6390_SGMII_INT_LINK_DOWN ||
+                               MV88E6390_SGMII_INT_LINK_UP)) {
+                        ret = IRQ_HANDLED;
+                        mv88e6390_serdes_irq_link_sgmii(chip, port->port, lane);
+                }
+        }
+out:
+        mutex_unlock(&chip->reg_lock);
+
+        return ret;
+}
+
+int mv88e6390_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port)
+{
+        int lane;
+        int err;
+
+        /* Only support ports 9 and 10 at the moment */
+        if (port < 9)
+                return 0;
+
+        lane = mv88e6390x_serdes_get_lane(chip, port);
+
+        if (lane == -ENODEV)
+                return 0;
+
+        if (lane < 0)
+                return lane;
+
+        chip->ports[port].serdes_irq = irq_find_mapping(chip->g2_irq.domain,
+                                                        port);
+        if (chip->ports[port].serdes_irq < 0) {
+                dev_err(chip->dev, "Unable to map SERDES irq: %d\n",
+                        chip->ports[port].serdes_irq);
+                return chip->ports[port].serdes_irq;
+        }
+
+        /* Requesting the IRQ will trigger irq callbacks. So we cannot
+         * hold the reg_lock.
+         */
+        mutex_unlock(&chip->reg_lock);
+        err = request_threaded_irq(chip->ports[port].serdes_irq, NULL,
+                                   mv88e6390_serdes_thread_fn,
+                                   IRQF_ONESHOT, "mv88e6xxx-serdes",
+                                   &chip->ports[port]);
+        mutex_lock(&chip->reg_lock);
+
+        if (err) {
+                dev_err(chip->dev, "Unable to request SERDES interrupt: %d\n",
+                        err);
+                return err;
+        }
+
+        return mv88e6390_serdes_irq_enable(chip, port, lane);
+}
+
+void mv88e6390_serdes_irq_free(struct mv88e6xxx_chip *chip, int port)
+{
+        int lane = mv88e6390x_serdes_get_lane(chip, port);
+
+        if (port < 9)
+                return;
+
+        if (lane < 0)
+                return;
+
+        mv88e6390_serdes_irq_disable(chip, port, lane);
+
+        /* Freeing the IRQ will trigger irq callbacks. So we cannot
+         * hold the reg_lock.
+         */
+        mutex_unlock(&chip->reg_lock);
+        free_irq(chip->ports[port].serdes_irq, &chip->ports[port]);
+        mutex_lock(&chip->reg_lock);
+}
+
 int mv88e6341_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on)
 {
         u8 cmode = chip->ports[port].cmode;
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index a64ca1974988..09da08cb5261 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -42,11 +42,27 @@
 #define MV88E6390_SGMII_CONTROL_RESET           BIT(15)
 #define MV88E6390_SGMII_CONTROL_LOOPBACK        BIT(14)
 #define MV88E6390_SGMII_CONTROL_PDOWN           BIT(11)
+#define MV88E6390_SGMII_STATUS          0x2001
+#define MV88E6390_SGMII_STATUS_AN_DONE          BIT(5)
+#define MV88E6390_SGMII_STATUS_REMOTE_FAULT     BIT(4)
+#define MV88E6390_SGMII_STATUS_LINK             BIT(2)
+#define MV88E6390_SGMII_INT_ENABLE      0xa001
+#define MV88E6390_SGMII_INT_SPEED_CHANGE        BIT(14)
+#define MV88E6390_SGMII_INT_DUPLEX_CHANGE       BIT(13)
+#define MV88E6390_SGMII_INT_PAGE_RX             BIT(12)
+#define MV88E6390_SGMII_INT_AN_COMPLETE         BIT(11)
+#define MV88E6390_SGMII_INT_LINK_DOWN           BIT(10)
+#define MV88E6390_SGMII_INT_LINK_UP             BIT(9)
+#define MV88E6390_SGMII_INT_SYMBOL_ERROR        BIT(8)
+#define MV88E6390_SGMII_INT_FALSE_CARRIER       BIT(7)
+#define MV88E6390_SGMII_INT_STATUS      0xa002
 
 int mv88e6341_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on);
 int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on);
 int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on);
 int mv88e6390x_serdes_power(struct mv88e6xxx_chip *chip, int port, bool on);
+int mv88e6390_serdes_irq_setup(struct mv88e6xxx_chip *chip, int port);
+void mv88e6390_serdes_irq_free(struct mv88e6xxx_chip *chip, int port);
 int mv88e6352_serdes_get_sset_count(struct mv88e6xxx_chip *chip, int port);
 int mv88e6352_serdes_get_strings(struct mv88e6xxx_chip *chip,
                                  int port, uint8_t *data);