[PATCH RFC net-next 2/5] net: dsa: b53: populate supported_interfaces and mac_capabilities

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

Populate the supported interfaces and MAC capabilities for the Broadcom
B53 DSA switches in preparation to using these for the generic
validation functionality.

The interface modes are derived from:
- b53_serdes_phylink_validate()
- SRAB mux configuration

NOTE: much of this conversion is a guess as the driver doesn't contain
sufficient information. I would appreciate a thorough review and
testing of this change before it is merged.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/dsa/b53/b53_common.c | 28 ++++++++++++++++++++++++++
 drivers/net/dsa/b53/b53_priv.h   |  2 ++
 drivers/net/dsa/b53/b53_serdes.c | 27 +++++++++++++++++++++++++
 drivers/net/dsa/b53/b53_serdes.h |  2 ++
 drivers/net/dsa/b53/b53_srab.c   | 34 ++++++++++++++++++++++++++++++++
 5 files changed, 93 insertions(+)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 7d62b0aeaae9..211c0e499370 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1353,6 +1353,33 @@ void b53_phylink_validate(struct dsa_switch *ds, int port,
 }
 EXPORT_SYMBOL(b53_phylink_validate);
 
+static void b53_phylink_get_caps(struct dsa_switch *ds, int port,
+				 struct phylink_config *config)
+{
+	struct b53_device *dev = ds->priv;
+
+	/* Internal ports need GMII for PHYLIB */
+	__set_bit(PHY_INTERFACE_MODE_GMII, config->supported_interfaces);
+
+	/* These switches appear to support MII and RevMII too, but beyond
+	 * this, the code gives very few clues. FIXME: We probably need more
+	 * interface modes here.
+	 */
+	__set_bit(PHY_INTERFACE_MODE_MII, config->supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_REVMII, config->supported_interfaces);
+
+	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+		MAC_10 | MAC_100;
+
+	/* 5325/5365 are not capable of gigabit speeds, everything else is */
+	if (!(is5325(dev) || is5365(dev)))
+		config->mac_capabilities |= MAC_1000;
+
+	/* Get the implementation specific capabilities */
+	if (dev->ops->phylink_get_caps)
+		dev->ops->phylink_get_caps(dev, port, config);
+}
+
 int b53_phylink_mac_link_state(struct dsa_switch *ds, int port,
 			       struct phylink_link_state *state)
 {
@@ -2262,6 +2289,7 @@ static const struct dsa_switch_ops b53_switch_ops = {
 	.phy_read		= b53_phy_read16,
 	.phy_write		= b53_phy_write16,
 	.adjust_link		= b53_adjust_link,
+	.phylink_get_caps	= b53_phylink_get_caps,
 	.phylink_validate	= b53_phylink_validate,
 	.phylink_mac_link_state	= b53_phylink_mac_link_state,
 	.phylink_mac_config	= b53_phylink_mac_config,
diff --git a/drivers/net/dsa/b53/b53_priv.h b/drivers/net/dsa/b53/b53_priv.h
index b41dc8ac2ca8..b9d1b4819c5f 100644
--- a/drivers/net/dsa/b53/b53_priv.h
+++ b/drivers/net/dsa/b53/b53_priv.h
@@ -46,6 +46,8 @@ struct b53_io_ops {
 	int (*phy_write16)(struct b53_device *dev, int addr, int reg, u16 value);
 	int (*irq_enable)(struct b53_device *dev, int port);
 	void (*irq_disable)(struct b53_device *dev, int port);
+	void (*phylink_get_caps)(struct b53_device *dev, int port,
+				 struct phylink_config *config);
 	u8 (*serdes_map_lane)(struct b53_device *dev, int port);
 	int (*serdes_link_state)(struct b53_device *dev, int port,
 				 struct phylink_link_state *state);
diff --git a/drivers/net/dsa/b53/b53_serdes.c b/drivers/net/dsa/b53/b53_serdes.c
index 5ae3d9783b68..7e1ec51ab4c9 100644
--- a/drivers/net/dsa/b53/b53_serdes.c
+++ b/drivers/net/dsa/b53/b53_serdes.c
@@ -180,6 +180,33 @@ void b53_serdes_phylink_validate(struct b53_device *dev, int port,
 }
 EXPORT_SYMBOL(b53_serdes_phylink_validate);
 
+void b53_serdes_phylink_get_caps(struct b53_device *dev, int port,
+				 struct phylink_config *config)
+{
+	u8 lane = b53_serdes_map_lane(dev, port);
+
+	if (lane == B53_INVALID_LANE)
+		return;
+
+	switch (lane) {
+	case 0:
+		/* It appears lane 0 supports 2500base-X and 1000base-X */
+		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
+			  config->supported_interfaces);
+		config->mac_capabilities |= MAC_2500FD;
+		fallthrough;
+	case 1:
+		/* It appears lane 1 only supports 1000base-X */
+		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
+			  config->supported_interfaces);
+		config->mac_capabilities |= MAC_1000FD;
+		break;
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL(b53_serdes_phylink_get_caps);
+
 int b53_serdes_init(struct b53_device *dev, int port)
 {
 	u8 lane = b53_serdes_map_lane(dev, port);
diff --git a/drivers/net/dsa/b53/b53_serdes.h b/drivers/net/dsa/b53/b53_serdes.h
index 55d280fe38e4..8fa24f7001aa 100644
--- a/drivers/net/dsa/b53/b53_serdes.h
+++ b/drivers/net/dsa/b53/b53_serdes.h
@@ -115,6 +115,8 @@ void b53_serdes_config(struct b53_device *dev, int port, unsigned int mode,
 void b53_serdes_an_restart(struct b53_device *dev, int port);
 void b53_serdes_link_set(struct b53_device *dev, int port, unsigned int mode,
 			 phy_interface_t interface, bool link_up);
+void b53_serdes_phylink_get_caps(struct b53_device *dev, int port,
+				 struct phylink_config *config);
 void b53_serdes_phylink_validate(struct b53_device *dev, int port,
 				unsigned long *supported,
 				struct phylink_link_state *state);
diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index 4591bb1c05d2..7d72f3b293d3 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -443,6 +443,39 @@ static void b53_srab_irq_disable(struct b53_device *dev, int port)
 	}
 }
 
+static void b53_srab_phylink_get_caps(struct b53_device *dev, int port,
+				      struct phylink_config *config)
+{
+	struct b53_srab_priv *priv = dev->priv;
+	struct b53_srab_port_priv *p = &priv->port_intrs[port];
+
+	switch (p->mode) {
+	case PHY_INTERFACE_MODE_SGMII:
+#if IS_ENABLED(CONFIG_B53_SERDES)
+		/* If p->mode indicates SGMII mode, that essentially means we
+		 * are using a serdes. As the serdes for the capabilities.
+		 */
+		b53_serdes_phylink_get_caps(dev, port, config);
+#endif
+		break;
+
+	case PHY_INTERFACE_MODE_NA:
+		break;
+
+	case PHY_INTERFACE_MODE_RGMII:
+		/* If we support RGMII, support all RGMII modes, since
+		 * that dictates the PHY delay settings.
+		 */
+		phy_interface_set_rgmii(config->supported_interfaces);
+		break;
+
+	default:
+		/* Some other mode (e.g. MII, GMII etc) */
+		__set_bit(p->mode, config->supported_interfaces);
+		break;
+	}
+}
+
 static const struct b53_io_ops b53_srab_ops = {
 	.read8 = b53_srab_read8,
 	.read16 = b53_srab_read16,
@@ -456,6 +489,7 @@ static const struct b53_io_ops b53_srab_ops = {
 	.write64 = b53_srab_write64,
 	.irq_enable = b53_srab_irq_enable,
 	.irq_disable = b53_srab_irq_disable,
+	.phylink_get_caps = b53_srab_phylink_get_caps,
 #if IS_ENABLED(CONFIG_B53_SERDES)
 	.serdes_map_lane = b53_srab_serdes_map_lane,
 	.serdes_link_state = b53_serdes_link_state,
-- 
2.30.2