net: dsa: mv88e6xxx: add infrastructure for phylink_pcs

Add infrastructure for phylink_pcs to the mv88e6xxx driver. This
involves adding a mac_select_pcs() hook so we can pass the PCS to
phylink at the appropriate time, and a PCS initialisation function.

As the various chip implementations are converted to use phylink_pcs,
they are no longer reliant on the legacy phylink behaviour. We detect
this by the use of this infrastructure, or the lack of any serdes.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

2 files changed, 60 insertions, 0 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index ab4db8ac1767..453dce75785f 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -833,6 +833,37 @@ static void mv88e6xxx_get_caps(struct dsa_switch *ds, int port,
 
 	if (chip->info->ops->port_max_speed_mode)
 		*default_interface = chip->info->ops->port_max_speed_mode(port);
+
+	/* If we have a .pcs_init, or don't have a .serdes_pcs_get_state,
+	 * serdes_pcs_config, serdes_pcs_an_restart, or serdes_pcs_link_up,
+	 * we are not legacy.
+	 */
+	if (chip->info->ops->pcs_init ||
+	    (!chip->info->ops->serdes_pcs_get_state &&
+	     !chip->info->ops->serdes_pcs_config &&
+	     !chip->info->ops->serdes_pcs_an_restart &&
+	     !chip->info->ops->serdes_pcs_link_up))
+		config->legacy_pre_march2020 = false;
+}
+
+static struct phylink_pcs *__maybe_unused
+mv88e6xxx_pcs_select(struct mv88e6xxx_chip *chip, int port,
+		     phy_interface_t interface)
+{
+	return chip->ports[port].pcs_private;
+}
+
+static struct phylink_pcs *mv88e6xxx_mac_select_pcs(struct dsa_switch *ds,
+						    int port,
+						    phy_interface_t interface)
+{
+	struct mv88e6xxx_chip *chip = ds->priv;
+	struct phylink_pcs *pcs = ERR_PTR(-EOPNOTSUPP);
+
+	if (chip->info->ops->pcs_select)
+		pcs = chip->info->ops->pcs_select(chip, port, interface);
+
+	return pcs;
 }
 
 static int mv88e6xxx_mac_prepare(struct dsa_switch *ds, int port,
@@ -3560,6 +3591,10 @@ static int mv88e6xxx_port_enable(struct dsa_switch *ds, int port,
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
+	/* Do not control power or request irqs if using PCS */
+	if (chip->info->ops->pcs_init)
+		return 0;
+
 	mv88e6xxx_reg_lock(chip);
 	err = mv88e6xxx_serdes_power(chip, port, true);
 	mv88e6xxx_reg_unlock(chip);
@@ -3571,6 +3606,10 @@ static void mv88e6xxx_port_disable(struct dsa_switch *ds, int port)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
 
+	/* Do not control power or request irqs if using PCS */
+	if (chip->info->ops->pcs_init)
+		return;
+
 	mv88e6xxx_reg_lock(chip);
 	if (mv88e6xxx_serdes_power(chip, port, false))
 		dev_err(chip->dev, "failed to power off SERDES\n");
@@ -3824,12 +3863,26 @@ out_resources:
 
 static int mv88e6xxx_port_setup(struct dsa_switch *ds, int port)
 {
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int err;
+
+	if (chip->info->ops->pcs_init) {
+		err = chip->info->ops->pcs_init(chip, port);
+		if (err)
+			return err;
+	}
+
 	return mv88e6xxx_setup_devlink_regions_port(ds, port);
 }
 
 static void mv88e6xxx_port_teardown(struct dsa_switch *ds, int port)
 {
+	struct mv88e6xxx_chip *chip = ds->priv;
+
 	mv88e6xxx_teardown_devlink_regions_port(ds, port);
+
+	if (chip->info->ops->pcs_teardown)
+		chip->info->ops->pcs_teardown(chip, port);
 }
 
 /* prod_id for switch families which do not have a PHY model number */
@@ -6811,6 +6864,7 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 	.port_setup		= mv88e6xxx_port_setup,
 	.port_teardown		= mv88e6xxx_port_teardown,
 	.phylink_get_caps	= mv88e6xxx_get_caps,
+	.phylink_mac_select_pcs	= mv88e6xxx_mac_select_pcs,
 	.phylink_mac_link_state	= mv88e6xxx_serdes_pcs_get_state,
 	.phylink_mac_prepare	= mv88e6xxx_mac_prepare,
 	.phylink_mac_config	= mv88e6xxx_mac_config,
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index e693154cf803..a87e442481f1 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -280,6 +280,7 @@ struct mv88e6xxx_port {
 	unsigned int serdes_irq;
 	char serdes_irq_name[64];
 	struct devlink_region *region;
+	void *pcs_private;
 };
 
 enum mv88e6xxx_region_id {
@@ -578,6 +579,11 @@ struct mv88e6xxx_ops {
 	/* SERDES lane mapping */
 	int (*serdes_get_lane)(struct mv88e6xxx_chip *chip, int port);
 
+	int (*pcs_init)(struct mv88e6xxx_chip *chip, int port);
+	void (*pcs_teardown)(struct mv88e6xxx_chip *chip, int port);
+	struct phylink_pcs *(*pcs_select)(struct mv88e6xxx_chip *chip, int port,
+					  phy_interface_t mode);
+
 	int (*serdes_pcs_get_state)(struct mv88e6xxx_chip *chip, int port,
 				    int lane, struct phylink_link_state *state);
 	int (*serdes_pcs_config)(struct mv88e6xxx_chip *chip, int port,