Merge branch 'net-dsa-vsc73xx-convert-to-phylink-and-do-some-cleanup'

Pawel Dembicki says:

====================
net: dsa: vsc73xx: convert to PHYLINK and do some cleanup

This patch series is a result of splitting a larger patch series [0],
where some parts needed to be refactored.

The first patch switches from a poll loop to read_poll_timeout.

The second patch is a simple conversion to phylink because adjust_link
won't work anymore.

The third patch is preparation for future use. Using the
"phy_interface_mode_is_rgmii" macro allows for the proper recognition
of all RGMII modes.

Patches 4-5 involve some cleanup: The fourth patch introduces
a definition with the maximum number of ports to avoid using
magic numbers. The next one fills in documentation.

[0] https://patchwork.kernel.org/project/netdevbpf/list/?series=841034&state=%2A&archive=both
====================

Link: https://lore.kernel.org/r/20240417205048.3542839-1-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 144 insertions, 138 deletions

diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c
index ae70eac3be28f8..4b031fefcec682 100644
--- a/drivers/net/dsa/vitesse-vsc73xx-core.c
+++ b/drivers/net/dsa/vitesse-vsc73xx-core.c
@@ -17,6 +17,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/iopoll.h>
 #include <linux/of.h>
 #include <linux/of_mdio.h>
 #include <linux/bitops.h>
@@ -268,6 +269,9 @@
 #define IS_7398(a) ((a)->chipid == VSC73XX_CHIPID_ID_7398)
 #define IS_739X(a) (IS_7395(a) || IS_7398(a))
 
+#define VSC73XX_POLL_SLEEP_US		1000
+#define VSC73XX_POLL_TIMEOUT_US		10000
+
 struct vsc73xx_counter {
 	u8 counter;
 	const char *name;
@@ -713,51 +717,44 @@ static void vsc73xx_init_port(struct vsc73xx *vsc, int port)
 		      port, VSC73XX_C_RX0, 0);
 }
 
-static void vsc73xx_adjust_enable_port(struct vsc73xx *vsc,
-				       int port, struct phy_device *phydev,
-				       u32 initval)
+static void vsc73xx_reset_port(struct vsc73xx *vsc, int port, u32 initval)
 {
-	u32 val = initval;
-	u8 seed;
-
-	/* Reset this port FIXME: break out subroutine */
-	val |= VSC73XX_MAC_CFG_RESET;
-	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG, val);
-
-	/* Seed the port randomness with randomness */
-	get_random_bytes(&seed, 1);
-	val |= seed << VSC73XX_MAC_CFG_SEED_OFFSET;
-	val |= VSC73XX_MAC_CFG_SEED_LOAD;
-	val |= VSC73XX_MAC_CFG_WEXC_DIS;
-	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG, val);
+	int ret, err;
+	u32 val;
 
-	/* Flow control for the PHY facing ports:
-	 * Use a zero delay pause frame when pause condition is left
-	 * Obey pause control frames
-	 * When generating pause frames, use 0xff as pause value
-	 */
-	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_FCCONF,
-		      VSC73XX_FCCONF_ZERO_PAUSE_EN |
-		      VSC73XX_FCCONF_FLOW_CTRL_OBEY |
-		      0xff);
+	/* Disable RX on this port */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
+			    VSC73XX_MAC_CFG,
+			    VSC73XX_MAC_CFG_RX_EN, 0);
 
-	/* Disallow backward dropping of frames from this port */
+	/* Discard packets */
 	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
-			    VSC73XX_SBACKWDROP, BIT(port), 0);
+			    VSC73XX_ARBDISC, BIT(port), BIT(port));
+
+	/* Wait until queue is empty */
+	ret = read_poll_timeout(vsc73xx_read, err,
+				err < 0 || (val & BIT(port)),
+				VSC73XX_POLL_SLEEP_US,
+				VSC73XX_POLL_TIMEOUT_US, false,
+				vsc, VSC73XX_BLOCK_ARBITER, 0,
+				VSC73XX_ARBEMPTY, &val);
+	if (ret)
+		dev_err(vsc->dev,
+			"timeout waiting for block arbiter\n");
+	else if (err < 0)
+		dev_err(vsc->dev, "error reading arbiter\n");
 
-	/* Enable TX, RX, deassert reset, stop loading seed */
-	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
-			    VSC73XX_MAC_CFG,
-			    VSC73XX_MAC_CFG_RESET | VSC73XX_MAC_CFG_SEED_LOAD |
-			    VSC73XX_MAC_CFG_TX_EN | VSC73XX_MAC_CFG_RX_EN,
-			    VSC73XX_MAC_CFG_TX_EN | VSC73XX_MAC_CFG_RX_EN);
+	/* Put this port into reset */
+	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG,
+		      VSC73XX_MAC_CFG_RESET | initval);
 }
 
-static void vsc73xx_adjust_link(struct dsa_switch *ds, int port,
-				struct phy_device *phydev)
+static void vsc73xx_mac_config(struct phylink_config *config, unsigned int mode,
+			       const struct phylink_link_state *state)
 {
-	struct vsc73xx *vsc = ds->priv;
-	u32 val;
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct vsc73xx *vsc = dp->ds->priv;
+	int port = dp->index;
 
 	/* Special handling of the CPU-facing port */
 	if (port == CPU_PORT) {
@@ -774,104 +771,93 @@ static void vsc73xx_adjust_link(struct dsa_switch *ds, int port,
 			      VSC73XX_ADVPORTM_ENA_GTX |
 			      VSC73XX_ADVPORTM_DDR_MODE);
 	}
+}
+
+static void vsc73xx_mac_link_down(struct phylink_config *config,
+				  unsigned int mode, phy_interface_t interface)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct vsc73xx *vsc = dp->ds->priv;
+	int port = dp->index;
 
-	/* This is the MAC confiuration that always need to happen
-	 * after a PHY or the CPU port comes up or down.
+	/* This routine is described in the datasheet (below ARBDISC register
+	 * description)
 	 */
-	if (!phydev->link) {
-		int maxloop = 10;
-
-		dev_dbg(vsc->dev, "port %d: went down\n",
-			port);
-
-		/* Disable RX on this port */
-		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
-				    VSC73XX_MAC_CFG,
-				    VSC73XX_MAC_CFG_RX_EN, 0);
-
-		/* Discard packets */
-		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
-				    VSC73XX_ARBDISC, BIT(port), BIT(port));
-
-		/* Wait until queue is empty */
-		vsc73xx_read(vsc, VSC73XX_BLOCK_ARBITER, 0,
-			     VSC73XX_ARBEMPTY, &val);
-		while (!(val & BIT(port))) {
-			msleep(1);
-			vsc73xx_read(vsc, VSC73XX_BLOCK_ARBITER, 0,
-				     VSC73XX_ARBEMPTY, &val);
-			if (--maxloop == 0) {
-				dev_err(vsc->dev,
-					"timeout waiting for block arbiter\n");
-				/* Continue anyway */
-				break;
-			}
-		}
+	vsc73xx_reset_port(vsc, port, 0);
+
+	/* Allow backward dropping of frames from this port */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
+			    VSC73XX_SBACKWDROP, BIT(port), BIT(port));
+
+	/* Receive mask (disable forwarding) */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ANALYZER, 0,
+			    VSC73XX_RECVMASK, BIT(port), 0);
+}
+
+static void vsc73xx_mac_link_up(struct phylink_config *config,
+				struct phy_device *phy, unsigned int mode,
+				phy_interface_t interface, int speed,
+				int duplex, bool tx_pause, bool rx_pause)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct vsc73xx *vsc = dp->ds->priv;
+	int port = dp->index;
+	u32 val;
+	u8 seed;
 
-		/* Put this port into reset */
-		vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG,
-			      VSC73XX_MAC_CFG_RESET);
+	if (speed == SPEED_1000)
+		val = VSC73XX_MAC_CFG_GIGA_MODE | VSC73XX_MAC_CFG_TX_IPG_1000M;
+	else
+		val = VSC73XX_MAC_CFG_TX_IPG_100_10M;
 
-		/* Accept packets again */
-		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
-				    VSC73XX_ARBDISC, BIT(port), 0);
+	if (phy_interface_mode_is_rgmii(interface))
+		val |= VSC73XX_MAC_CFG_CLK_SEL_1000M;
+	else
+		val |= VSC73XX_MAC_CFG_CLK_SEL_EXT;
 
-		/* Allow backward dropping of frames from this port */
-		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
-				    VSC73XX_SBACKWDROP, BIT(port), BIT(port));
+	if (duplex == DUPLEX_FULL)
+		val |= VSC73XX_MAC_CFG_FDX;
 
-		/* Receive mask (disable forwarding) */
-		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ANALYZER, 0,
-				    VSC73XX_RECVMASK, BIT(port), 0);
+	/* This routine is described in the datasheet (below ARBDISC register
+	 * description)
+	 */
+	vsc73xx_reset_port(vsc, port, val);
 
-		return;
-	}
+	/* Seed the port randomness with randomness */
+	get_random_bytes(&seed, 1);
+	val |= seed << VSC73XX_MAC_CFG_SEED_OFFSET;
+	val |= VSC73XX_MAC_CFG_SEED_LOAD;
+	val |= VSC73XX_MAC_CFG_WEXC_DIS;
+	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG, val);
 
-	/* Figure out what speed was negotiated */
-	if (phydev->speed == SPEED_1000) {
-		dev_dbg(vsc->dev, "port %d: 1000 Mbit mode full duplex\n",
-			port);
-
-		/* Set up default for internal port or external RGMII */
-		if (phydev->interface == PHY_INTERFACE_MODE_RGMII)
-			val = VSC73XX_MAC_CFG_1000M_F_RGMII;
-		else
-			val = VSC73XX_MAC_CFG_1000M_F_PHY;
-		vsc73xx_adjust_enable_port(vsc, port, phydev, val);
-	} else if (phydev->speed == SPEED_100) {
-		if (phydev->duplex == DUPLEX_FULL) {
-			val = VSC73XX_MAC_CFG_100_10M_F_PHY;
-			dev_dbg(vsc->dev,
-				"port %d: 100 Mbit full duplex mode\n",
-				port);
-		} else {
-			val = VSC73XX_MAC_CFG_100_10M_H_PHY;
-			dev_dbg(vsc->dev,
-				"port %d: 100 Mbit half duplex mode\n",
-				port);
-		}
-		vsc73xx_adjust_enable_port(vsc, port, phydev, val);
-	} else if (phydev->speed == SPEED_10) {
-		if (phydev->duplex == DUPLEX_FULL) {
-			val = VSC73XX_MAC_CFG_100_10M_F_PHY;
-			dev_dbg(vsc->dev,
-				"port %d: 10 Mbit full duplex mode\n",
-				port);
-		} else {
-			val = VSC73XX_MAC_CFG_100_10M_H_PHY;
-			dev_dbg(vsc->dev,
-				"port %d: 10 Mbit half duplex mode\n",
-				port);
-		}
-		vsc73xx_adjust_enable_port(vsc, port, phydev, val);
-	} else {
-		dev_err(vsc->dev,
-			"could not adjust link: unknown speed\n");
-	}
+	/* Flow control for the PHY facing ports:
+	 * Use a zero delay pause frame when pause condition is left
+	 * Obey pause control frames
+	 * When generating pause frames, use 0xff as pause value
+	 */
+	vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_FCCONF,
+		      VSC73XX_FCCONF_ZERO_PAUSE_EN |
+		      VSC73XX_FCCONF_FLOW_CTRL_OBEY |
+		      0xff);
 
-	/* Enable port (forwarding) in the receieve mask */
+	/* Accept packets again */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
+			    VSC73XX_ARBDISC, BIT(port), 0);
+
+	/* Enable port (forwarding) in the receive mask */
 	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ANALYZER, 0,
 			    VSC73XX_RECVMASK, BIT(port), BIT(port));
+
+	/* Disallow backward dropping of frames from this port */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
+			    VSC73XX_SBACKWDROP, BIT(port), 0);
+
+	/* Enable TX, RX, deassert reset, stop loading seed */
+	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
+			    VSC73XX_MAC_CFG,
+			    VSC73XX_MAC_CFG_RESET | VSC73XX_MAC_CFG_SEED_LOAD |
+			    VSC73XX_MAC_CFG_TX_EN | VSC73XX_MAC_CFG_RX_EN,
+			    VSC73XX_MAC_CFG_TX_EN | VSC73XX_MAC_CFG_RX_EN);
 }
 
 static int vsc73xx_port_enable(struct dsa_switch *ds, int port,
@@ -1053,12 +1039,17 @@ static void vsc73xx_phylink_get_caps(struct dsa_switch *dsa, int port,
 	config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100 | MAC_1000;
 }
 
+static const struct phylink_mac_ops vsc73xx_phylink_mac_ops = {
+	.mac_config = vsc73xx_mac_config,
+	.mac_link_down = vsc73xx_mac_link_down,
+	.mac_link_up = vsc73xx_mac_link_up,
+};
+
 static const struct dsa_switch_ops vsc73xx_ds_ops = {
 	.get_tag_protocol = vsc73xx_get_tag_protocol,
 	.setup = vsc73xx_setup,
 	.phy_read = vsc73xx_phy_read,
 	.phy_write = vsc73xx_phy_write,
-	.adjust_link = vsc73xx_adjust_link,
 	.get_strings = vsc73xx_get_strings,
 	.get_ethtool_stats = vsc73xx_get_ethtool_stats,
 	.get_sset_count = vsc73xx_get_sset_count,
@@ -1195,26 +1186,16 @@ int vsc73xx_probe(struct vsc73xx *vsc)
 		 vsc->addr[0], vsc->addr[1], vsc->addr[2],
 		 vsc->addr[3], vsc->addr[4], vsc->addr[5]);
 
-	/* The VSC7395 switch chips have 5+1 ports which means 5
-	 * ordinary ports and a sixth CPU port facing the processor
-	 * with an RGMII interface. These ports are numbered 0..4
-	 * and 6, so they leave a "hole" in the port map for port 5,
-	 * which is invalid.
-	 *
-	 * The VSC7398 has 8 ports, port 7 is again the CPU port.
-	 *
-	 * We allocate 8 ports and avoid access to the nonexistant
-	 * ports.
-	 */
 	vsc->ds = devm_kzalloc(dev, sizeof(*vsc->ds), GFP_KERNEL);
 	if (!vsc->ds)
 		return -ENOMEM;
 
 	vsc->ds->dev = dev;
-	vsc->ds->num_ports = 8;
+	vsc->ds->num_ports = VSC73XX_MAX_NUM_PORTS;
 	vsc->ds->priv = vsc;
 
 	vsc->ds->ops = &vsc73xx_ds_ops;
+	vsc->ds->phylink_mac_ops = &vsc73xx_phylink_mac_ops;
 	ret = dsa_register_switch(vsc->ds);
 	if (ret) {
 		dev_err(dev, "unable to register switch (%d)\n", ret);
diff --git a/drivers/net/dsa/vitesse-vsc73xx.h b/drivers/net/dsa/vitesse-vsc73xx.h
index 30b1f0a36566d3..2997f7e108b18a 100644
--- a/drivers/net/dsa/vitesse-vsc73xx.h
+++ b/drivers/net/dsa/vitesse-vsc73xx.h
@@ -3,8 +3,28 @@
 #include <linux/etherdevice.h>
 #include <linux/gpio/driver.h>
 
+/* The VSC7395 switch chips have 5+1 ports which means 5 ordinary ports and
+ * a sixth CPU port facing the processor with an RGMII interface. These ports
+ * are numbered 0..4 and 6, so they leave a "hole" in the port map for port 5,
+ * which is invalid.
+ *
+ * The VSC7398 has 8 ports, port 7 is again the CPU port.
+ *
+ * We allocate 8 ports and avoid access to the nonexistent ports.
+ */
+#define VSC73XX_MAX_NUM_PORTS	8
+
 /**
- * struct vsc73xx - VSC73xx state container
+ * struct vsc73xx - VSC73xx state container: main data structure
+ * @dev: The device pointer
+ * @reset: The descriptor for the GPIO line tied to the reset pin
+ * @ds: Pointer to the DSA core structure
+ * @gc: Main structure of the GPIO controller
+ * @chipid: Storage for the Chip ID value read from the CHIPID register of the
+ *	switch
+ * @addr: MAC address used in flow control frames
+ * @ops: Structure with hardware-dependent operations
+ * @priv: Pointer to the configuration interface structure
  */
 struct vsc73xx {
 	struct device			*dev;
@@ -17,6 +37,11 @@ struct vsc73xx {
 	void				*priv;
 };
 
+/**
+ * struct vsc73xx_ops - VSC73xx methods container
+ * @read: Method for register reading over the hardware-dependent interface
+ * @write: Method for register writing over the hardware-dependent interface
+ */
 struct vsc73xx_ops {
 	int (*read)(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
 		    u32 *val);