Merge branch 'Convert-Felix-DSA-switch-to-PHYLINK'

Vladimir Oltean says:

====================
Convert Felix DSA switch to PHYLINK

Unlike most other conversions, this one is not by far a trivial one, and should
be seen as "Layerscape PCS meets PHYLINK". Actually, the PCS doesn't
need a lot of hand-holding and most of our other devices 'just work'
(this one included) without any sort of operating system awareness, just
an initialization procedure done typically in the bootloader.
Our issues start when the PCS stops from "just working", and that is
where PHYLINK comes in handy.

The PCS is not specific to the Vitesse / Microsemi / Microchip switching core
at all. Variations of this SerDes/PCS design can also be found on DPAA1 and
DPAA2 hardware.

The main idea of the abstraction provided is that the PCS looks so much like a
PHY device, that we model it as an actual PHY device and run the generic PHY
functions on it, where appropriate.

The 4xSGMII, QSGMII and QSXGMII modes are fairly straightforward.

The SerDes protocol which the driver calls 2500Base-X mode (a misnomer) is more
interesting. There is a description of how it works and what can be done with
it in patch 9/9 (in a comment above vsc9959_pcs_init_2500basex).
In short, it is a fixed speed protocol with no auto-negotiation whatsoever.
From my research of the SGMII-2500 patent [1], it has nothing to do with
SGMII-2500. That one:
* does not define any change to the AN base page compared to plain 10/100/1000
  SGMII. This implies that the 2500 speed is not negotiable, but the other
  speeds are. In our case, when the SerDes is configured for this protocol it's
  configured for good, there's no going back to SGMII.
* runs at a higher base frequency than regular SGMII. So SGMII-2500 operating
  at 1000 Mbps wouldn't interoperate with plain SGMII at 1000 Mbps. Strange,
  but ok..
* Emulates lower link speeds than 2500 by duplicating the codewords twice, then
  thrice, then twice again etc (2.5/25/250 times on average). The Layerscape
  PCS doesn't do that (it is fixed at 2500 Mbaud).

But on the other hand it isn't completely compatible with Base-X either,
since it doesn't do 802.3z / clause 37 auto negotiation (flow control,
local/remote fault etc). It is compatible with 2500Base-X without
in-band AN, and that is exactly how we decided to expose it (this is
actually similar to what others do).

For SGMII and USXGMII, the driver is using the PHYLINK 'managed =
"in-band-status"' DTS binding to figure out whether in-band AN is
expected to be enabled in the PCS or not. It is expected that the
attached PHY follows suite, but there is a gap here: the PHY driver does
not react to this setting, so only one of "AN on" and "AN off" works on
any particular PHY, even though that PHY might support bypassing the
SGMII AN process, as is the case on the VSC8514 PHY present on the
LS1028A-RDB board. A separate series will be sent to propose a way to
deal with that.

I dropped the Ocelot PHYLINK conversion because:
* I don't have VSC7514 hardware anyway
* The hardware is so different in this regard that there's almost nothing to
  share anyway.

Changes in v5:

- Added the register write to DEV_CLOCK_CFG back in
  felix_phylink_mac_config in patch 9/9.

Changes in v4:

- This is mostly a resend of v3, with the only notable change that I've
  dropped the PHY core patches for in_band_autoneg and I'll propose them
  independently.

v1 series:
https://www.spinics.net/lists/netdev/msg613869.html

RFC v2 series:
https://www.spinics.net/lists/netdev/msg620128.html

v3 series:
https://www.spinics.net/lists/netdev/msg622060.html

v4 series:
https://www.spinics.net/lists/netdev/msg622606.html

[0]: https://www.spinics.net/lists/netdev/msg613869.html
[1]: https://patents.google.com/patent/US7356047B1/en
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/sfp-phylink.rst

@@ -251,7 +251,8 @@ this documentation.
 	phylink_mac_change(priv->phylink, link_is_up);
 
     where ``link_is_up`` is true if the link is currently up or false
-    otherwise.
+    otherwise. If a MAC is unable to provide these interrupts, then
+    it should set ``priv->phylink_config.pcs_poll = true;`` in step 9.
 
 11. Verify that the driver does not call::
 

drivers/net/dsa/ocelot/Kconfig

@@ -3,8 +3,10 @@ config NET_DSA_MSCC_FELIX
 	tristate "Ocelot / Felix Ethernet switch support"
 	depends on NET_DSA && PCI
 	depends on NET_VENDOR_MICROSEMI
+	depends on NET_VENDOR_FREESCALE
 	select MSCC_OCELOT_SWITCH
 	select NET_DSA_TAG_OCELOT
+	select FSL_ENETC_MDIO
 	help
 	  This driver supports the VSC9959 network switch, which is a member of
 	  the Vitesse / Microsemi / Microchip Ocelot family of switching cores.

drivers/net/dsa/ocelot/felix.c

@@ -2,9 +2,14 @@
 /* Copyright 2019 NXP Semiconductors
  */
 #include <uapi/linux/if_bridge.h>
+#include <soc/mscc/ocelot_qsys.h>
+#include <soc/mscc/ocelot_sys.h>
+#include <soc/mscc/ocelot_dev.h>
+#include <soc/mscc/ocelot_ana.h>
 #include <soc/mscc/ocelot.h>
 #include <linux/packing.h>
 #include <linux/module.h>
+#include <linux/of_net.h>
 #include <linux/pci.h>
 #include <linux/of.h>
 #include <net/dsa.h>
@@ -26,14 +31,6 @@ static int felix_set_ageing_time(struct dsa_switch *ds,
 	return 0;
 }
 
-static void felix_adjust_link(struct dsa_switch *ds, int port,
-			      struct phy_device *phydev)
-{
-	struct ocelot *ocelot = ds->priv;
-
-	ocelot_adjust_link(ocelot, port, phydev);
-}
-
 static int felix_fdb_dump(struct dsa_switch *ds, int port,
 			  dsa_fdb_dump_cb_t *cb, void *data)
 {
@@ -155,6 +152,138 @@ static void felix_port_disable(struct dsa_switch *ds, int port)
 	return ocelot_port_disable(ocelot, port);
 }
 
+static void felix_phylink_validate(struct dsa_switch *ds, int port,
+				   unsigned long *supported,
+				   struct phylink_link_state *state)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
+
+	if (state->interface != PHY_INTERFACE_MODE_NA &&
+	    state->interface != ocelot_port->phy_mode) {
+		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
+		return;
+	}
+
+	/* No half-duplex. */
+	phylink_set_port_modes(mask);
+	phylink_set(mask, Autoneg);
+	phylink_set(mask, Pause);
+	phylink_set(mask, Asym_Pause);
+	if (state->interface != PHY_INTERFACE_MODE_2500BASEX) {
+		phylink_set(mask, 10baseT_Full);
+		phylink_set(mask, 100baseT_Full);
+		phylink_set(mask, 1000baseT_Full);
+	}
+	/* The internal ports that run at 2.5G are overclocked GMII */
+	if (state->interface == PHY_INTERFACE_MODE_GMII ||
+	    state->interface == PHY_INTERFACE_MODE_2500BASEX ||
+	    state->interface == PHY_INTERFACE_MODE_USXGMII) {
+		phylink_set(mask, 2500baseT_Full);
+		phylink_set(mask, 2500baseX_Full);
+	}
+
+	bitmap_and(supported, supported, mask,
+		   __ETHTOOL_LINK_MODE_MASK_NBITS);
+	bitmap_and(state->advertising, state->advertising, mask,
+		   __ETHTOOL_LINK_MODE_MASK_NBITS);
+}
+
+static int felix_phylink_mac_pcs_get_state(struct dsa_switch *ds, int port,
+					   struct phylink_link_state *state)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct felix *felix = ocelot_to_felix(ocelot);
+
+	if (felix->info->pcs_link_state)
+		felix->info->pcs_link_state(ocelot, port, state);
+
+	return 0;
+}
+
+static void felix_phylink_mac_config(struct dsa_switch *ds, int port,
+				     unsigned int link_an_mode,
+				     const struct phylink_link_state *state)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+	struct felix *felix = ocelot_to_felix(ocelot);
+	u32 mac_fc_cfg;
+
+	/* Take port out of reset by clearing the MAC_TX_RST, MAC_RX_RST and
+	 * PORT_RST bits in CLOCK_CFG
+	 */
+	ocelot_port_writel(ocelot_port, DEV_CLOCK_CFG_LINK_SPEED(state->speed),
+			   DEV_CLOCK_CFG);
+
+	/* Flow control. Link speed is only used here to evaluate the time
+	 * specification in incoming pause frames.
+	 */
+	mac_fc_cfg = SYS_MAC_FC_CFG_FC_LINK_SPEED(state->speed);
+	if (state->pause & MLO_PAUSE_RX)
+		mac_fc_cfg |= SYS_MAC_FC_CFG_RX_FC_ENA;
+	if (state->pause & MLO_PAUSE_TX)
+		mac_fc_cfg |= SYS_MAC_FC_CFG_TX_FC_ENA |
+			      SYS_MAC_FC_CFG_PAUSE_VAL_CFG(0xffff) |
+			      SYS_MAC_FC_CFG_FC_LATENCY_CFG(0x7) |
+			      SYS_MAC_FC_CFG_ZERO_PAUSE_ENA;
+	ocelot_write_rix(ocelot, mac_fc_cfg, SYS_MAC_FC_CFG, port);
+
+	ocelot_write_rix(ocelot, 0, ANA_POL_FLOWC, port);
+
+	if (felix->info->pcs_init)
+		felix->info->pcs_init(ocelot, port, link_an_mode, state);
+}
+
+static void felix_phylink_mac_an_restart(struct dsa_switch *ds, int port)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct felix *felix = ocelot_to_felix(ocelot);
+
+	if (felix->info->pcs_an_restart)
+		felix->info->pcs_an_restart(ocelot, port);
+}
+
+static void felix_phylink_mac_link_down(struct dsa_switch *ds, int port,
+					unsigned int link_an_mode,
+					phy_interface_t interface)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+	ocelot_port_writel(ocelot_port, 0, DEV_MAC_ENA_CFG);
+	ocelot_rmw_rix(ocelot, 0, QSYS_SWITCH_PORT_MODE_PORT_ENA,
+		       QSYS_SWITCH_PORT_MODE, port);
+}
+
+static void felix_phylink_mac_link_up(struct dsa_switch *ds, int port,
+				      unsigned int link_an_mode,
+				      phy_interface_t interface,
+				      struct phy_device *phydev)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+	/* Enable MAC module */
+	ocelot_port_writel(ocelot_port, DEV_MAC_ENA_CFG_RX_ENA |
+			   DEV_MAC_ENA_CFG_TX_ENA, DEV_MAC_ENA_CFG);
+
+	/* Enable receiving frames on the port, and activate auto-learning of
+	 * MAC addresses.
+	 */
+	ocelot_write_gix(ocelot, ANA_PORT_PORT_CFG_LEARNAUTO |
+			 ANA_PORT_PORT_CFG_RECV_ENA |
+			 ANA_PORT_PORT_CFG_PORTID_VAL(port),
+			 ANA_PORT_PORT_CFG, port);
+
+	/* Core: Enable port for frame transfer */
+	ocelot_write_rix(ocelot, QSYS_SWITCH_PORT_MODE_INGRESS_DROP_MODE |
+			 QSYS_SWITCH_PORT_MODE_SCH_NEXT_CFG(1) |
+			 QSYS_SWITCH_PORT_MODE_PORT_ENA,
+			 QSYS_SWITCH_PORT_MODE, port);
+}
+
 static void felix_get_strings(struct dsa_switch *ds, int port,
 			      u32 stringset, u8 *data)
 {
@@ -185,10 +314,76 @@ static int felix_get_ts_info(struct dsa_switch *ds, int port,
 	return ocelot_get_ts_info(ocelot, port, info);
 }
 
+static int felix_parse_ports_node(struct felix *felix,
+				  struct device_node *ports_node,
+				  phy_interface_t *port_phy_modes)
+{
+	struct ocelot *ocelot = &felix->ocelot;
+	struct device *dev = felix->ocelot.dev;
+	struct device_node *child;
+
+	for_each_child_of_node(ports_node, child) {
+		phy_interface_t phy_mode;
+		u32 port;
+		int err;
+
+		/* Get switch port number from DT */
+		if (of_property_read_u32(child, "reg", &port) < 0) {
+			dev_err(dev, "Port number not defined in device tree "
+				"(property \"reg\")\n");
+			of_node_put(child);
+			return -ENODEV;
+		}
+
+		/* Get PHY mode from DT */
+		err = of_get_phy_mode(child, &phy_mode);
+		if (err) {
+			dev_err(dev, "Failed to read phy-mode or "
+				"phy-interface-type property for port %d\n",
+				port);
+			of_node_put(child);
+			return -ENODEV;
+		}
+
+		err = felix->info->prevalidate_phy_mode(ocelot, port, phy_mode);
+		if (err < 0) {
+			dev_err(dev, "Unsupported PHY mode %s on port %d\n",
+				phy_modes(phy_mode), port);
+			return err;
+		}
+
+		port_phy_modes[port] = phy_mode;
+	}
+
+	return 0;
+}
+
+static int felix_parse_dt(struct felix *felix, phy_interface_t *port_phy_modes)
+{
+	struct device *dev = felix->ocelot.dev;
+	struct device_node *switch_node;
+	struct device_node *ports_node;
+	int err;
+
+	switch_node = dev->of_node;
+
+	ports_node = of_get_child_by_name(switch_node, "ports");
+	if (!ports_node) {
+		dev_err(dev, "Incorrect bindings: absent \"ports\" node\n");
+		return -ENODEV;
+	}
+
+	err = felix_parse_ports_node(felix, ports_node, port_phy_modes);
+	of_node_put(ports_node);
+
+	return err;
+}
+
 static int felix_init_structs(struct felix *felix, int num_phys_ports)
 {
 	struct ocelot *ocelot = &felix->ocelot;
-	resource_size_t base;
+	phy_interface_t *port_phy_modes;
+	resource_size_t switch_base;
 	int port, i, err;
 
 	ocelot->num_phys_ports = num_phys_ports;
@@ -203,7 +398,19 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	ocelot->shared_queue_sz	= felix->info->shared_queue_sz;
 	ocelot->ops		= felix->info->ops;
 
-	base = pci_resource_start(felix->pdev, felix->info->pci_bar);
+	port_phy_modes = kcalloc(num_phys_ports, sizeof(phy_interface_t),
+				 GFP_KERNEL);
+	if (!port_phy_modes)
+		return -ENOMEM;
+
+	err = felix_parse_dt(felix, port_phy_modes);
+	if (err) {
+		kfree(port_phy_modes);
+		return err;
+	}
+
+	switch_base = pci_resource_start(felix->pdev,
+					 felix->info->switch_pci_bar);
 
 	for (i = 0; i < TARGET_MAX; i++) {
 		struct regmap *target;
@@ -214,13 +421,14 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 
 		res = &felix->info->target_io_res[i];
 		res->flags = IORESOURCE_MEM;
-		res->start += base;
-		res->end += base;
+		res->start += switch_base;
+		res->end += switch_base;
 
 		target = ocelot_regmap_init(ocelot, res);
 		if (IS_ERR(target)) {
 			dev_err(ocelot->dev,
 				"Failed to map device memory space\n");
+			kfree(port_phy_modes);
 			return PTR_ERR(target);
 		}
 
@@ -230,6 +438,7 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	err = ocelot_regfields_init(ocelot, felix->info->regfields);
 	if (err) {
 		dev_err(ocelot->dev, "failed to init reg fields map\n");
+		kfree(port_phy_modes);
 		return err;
 	}
 
@@ -244,26 +453,37 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 		if (!ocelot_port) {
 			dev_err(ocelot->dev,
 				"failed to allocate port memory\n");
+			kfree(port_phy_modes);
 			return -ENOMEM;
 		}
 
 		res = &felix->info->port_io_res[port];
 		res->flags = IORESOURCE_MEM;
-		res->start += base;
-		res->end += base;
+		res->start += switch_base;
+		res->end += switch_base;
 
 		port_regs = devm_ioremap_resource(ocelot->dev, res);
 		if (IS_ERR(port_regs)) {
 			dev_err(ocelot->dev,
 				"failed to map registers for port %d\n", port);
+			kfree(port_phy_modes);
 			return PTR_ERR(port_regs);
 		}
 
+		ocelot_port->phy_mode = port_phy_modes[port];
 		ocelot_port->ocelot = ocelot;
 		ocelot_port->regs = port_regs;
 		ocelot->ports[port] = ocelot_port;
 	}
 
+	kfree(port_phy_modes);
+
+	if (felix->info->mdio_bus_alloc) {
+		err = felix->info->mdio_bus_alloc(ocelot);
+		if (err < 0)
+			return err;
+	}
+
 	return 0;
 }
 
@@ -293,12 +513,22 @@ static int felix_setup(struct dsa_switch *ds)
 					    OCELOT_TAG_PREFIX_LONG);
 	}
 
+	/* It looks like the MAC/PCS interrupt register - PM0_IEVENT (0x8040)
+	 * isn't instantiated for the Felix PF.
+	 * In-band AN may take a few ms to complete, so we need to poll.
+	 */
+	ds->pcs_poll = true;
+
 	return 0;
 }
 
 static void felix_teardown(struct dsa_switch *ds)
 {
 	struct ocelot *ocelot = ds->priv;
+	struct felix *felix = ocelot_to_felix(ocelot);
+
+	if (felix->info->mdio_bus_free)
+		felix->info->mdio_bus_free(ocelot);
 
 	/* stop workqueue thread */
 	ocelot_deinit(ocelot);
@@ -369,7 +599,12 @@ static const struct dsa_switch_ops felix_switch_ops = {
 	.get_ethtool_stats	= felix_get_ethtool_stats,
 	.get_sset_count		= felix_get_sset_count,
 	.get_ts_info		= felix_get_ts_info,
-	.adjust_link		= felix_adjust_link,
+	.phylink_validate	= felix_phylink_validate,
+	.phylink_mac_link_state	= felix_phylink_mac_pcs_get_state,
+	.phylink_mac_config	= felix_phylink_mac_config,
+	.phylink_mac_an_restart	= felix_phylink_mac_an_restart,
+	.phylink_mac_link_down	= felix_phylink_mac_link_down,
+	.phylink_mac_link_up	= felix_phylink_mac_link_up,
 	.port_enable		= felix_port_enable,
 	.port_disable		= felix_port_disable,
 	.port_fdb_dump		= felix_fdb_dump,