net: mscc: Add initial Ocelot switch support

Add a driver for Microsemi Ocelot Ethernet switch support.

This makes two modules:
mscc_ocelot_common handles all the common features that doesn't depend on
how the switch is integrated in the SoC. Currently, it handles offloading
bridging to the hardware. ocelot_io.c handles register accesses. This is
unfortunately needed because the register layout is packed and then depends
on the number of ports available on the switch. The register definition
files are automatically generated.

ocelot_board handles the switch integration on the SoC and on the board.

Frame injection and extraction to/from the CPU port is currently done using
register accesses which is quite slow. DMA is possible but the port is not
able to absorb the whole switch bandwidth.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 316 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot_board.c b/drivers/net/ethernet/mscc/ocelot_board.c
new file mode 100644
index 000000000000..18df7d934e81
--- /dev/null
+++ b/drivers/net/ethernet/mscc/ocelot_board.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Microsemi Ocelot Switch driver
+ *
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of_mdio.h>
+#include <linux/of_platform.h>
+#include <linux/skbuff.h>
+
+#include "ocelot.h"
+
+static int ocelot_parse_ifh(u32 *ifh, struct frame_info *info)
+{
+	int i;
+	u8 llen, wlen;
+
+	/* The IFH is in network order, switch to CPU order */
+	for (i = 0; i < IFH_LEN; i++)
+		ifh[i] = ntohl((__force __be32)ifh[i]);
+
+	wlen = (ifh[1] >> 7) & 0xff;
+	llen = (ifh[1] >> 15) & 0x3f;
+	info->len = OCELOT_BUFFER_CELL_SZ * wlen + llen - 80;
+
+	info->port = (ifh[2] & GENMASK(14, 11)) >> 11;
+
+	info->cpuq = (ifh[3] & GENMASK(27, 20)) >> 20;
+	info->tag_type = (ifh[3] & GENMASK(16, 16)) >> 16;
+	info->vid = ifh[3] & GENMASK(11, 0);
+
+	return 0;
+}
+
+static int ocelot_rx_frame_word(struct ocelot *ocelot, u8 grp, bool ifh,
+				u32 *rval)
+{
+	u32 val;
+	u32 bytes_valid;
+
+	val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+	if (val == XTR_NOT_READY) {
+		if (ifh)
+			return -EIO;
+
+		do {
+			val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		} while (val == XTR_NOT_READY);
+	}
+
+	switch (val) {
+	case XTR_ABORT:
+		return -EIO;
+	case XTR_EOF_0:
+	case XTR_EOF_1:
+	case XTR_EOF_2:
+	case XTR_EOF_3:
+	case XTR_PRUNED:
+		bytes_valid = XTR_VALID_BYTES(val);
+		val = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		if (val == XTR_ESCAPE)
+			*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+		else
+			*rval = val;
+
+		return bytes_valid;
+	case XTR_ESCAPE:
+		*rval = ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+
+		return 4;
+	default:
+		*rval = val;
+
+		return 4;
+	}
+}
+
+static irqreturn_t ocelot_xtr_irq_handler(int irq, void *arg)
+{
+	struct ocelot *ocelot = arg;
+	int i = 0, grp = 0;
+	int err = 0;
+
+	if (!(ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp)))
+		return IRQ_NONE;
+
+	do {
+		struct sk_buff *skb;
+		struct net_device *dev;
+		u32 *buf;
+		int sz, len;
+		u32 ifh[4];
+		u32 val;
+		struct frame_info info;
+
+		for (i = 0; i < IFH_LEN; i++) {
+			err = ocelot_rx_frame_word(ocelot, grp, true, &ifh[i]);
+			if (err != 4)
+				break;
+		}
+
+		if (err != 4)
+			break;
+
+		ocelot_parse_ifh(ifh, &info);
+
+		dev = ocelot->ports[info.port]->dev;
+
+		skb = netdev_alloc_skb(dev, info.len);
+
+		if (unlikely(!skb)) {
+			netdev_err(dev, "Unable to allocate sk_buff\n");
+			err = -ENOMEM;
+			break;
+		}
+		buf = (u32 *)skb_put(skb, info.len);
+
+		len = 0;
+		do {
+			sz = ocelot_rx_frame_word(ocelot, grp, false, &val);
+			*buf++ = val;
+			len += sz;
+		} while ((sz == 4) && (len < info.len));
+
+		if (sz < 0) {
+			err = sz;
+			break;
+		}
+
+		/* Everything we see on an interface that is in the HW bridge
+		 * has already been forwarded.
+		 */
+		if (ocelot->bridge_mask & BIT(info.port))
+			skb->offload_fwd_mark = 1;
+
+		skb->protocol = eth_type_trans(skb, dev);
+		netif_rx(skb);
+		dev->stats.rx_bytes += len;
+		dev->stats.rx_packets++;
+	} while (ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp));
+
+	if (err)
+		while (ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp))
+			ocelot_read_rix(ocelot, QS_XTR_RD, grp);
+
+	return IRQ_HANDLED;
+}
+
+static const struct of_device_id mscc_ocelot_match[] = {
+	{ .compatible = "mscc,vsc7514-switch" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mscc_ocelot_match);
+
+static int mscc_ocelot_probe(struct platform_device *pdev)
+{
+	int err, irq;
+	unsigned int i;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *ports, *portnp;
+	struct ocelot *ocelot;
+	u32 val;
+
+	struct {
+		enum ocelot_target id;
+		char *name;
+	} res[] = {
+		{ SYS, "sys" },
+		{ REW, "rew" },
+		{ QSYS, "qsys" },
+		{ ANA, "ana" },
+		{ QS, "qs" },
+		{ HSIO, "hsio" },
+	};
+
+	if (!np && !pdev->dev.platform_data)
+		return -ENODEV;
+
+	ocelot = devm_kzalloc(&pdev->dev, sizeof(*ocelot), GFP_KERNEL);
+	if (!ocelot)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ocelot);
+	ocelot->dev = &pdev->dev;
+
+	for (i = 0; i < ARRAY_SIZE(res); i++) {
+		struct regmap *target;
+
+		target = ocelot_io_platform_init(ocelot, pdev, res[i].name);
+		if (IS_ERR(target))
+			return PTR_ERR(target);
+
+		ocelot->targets[res[i].id] = target;
+	}
+
+	err = ocelot_chip_init(ocelot);
+	if (err)
+		return err;
+
+	irq = platform_get_irq_byname(pdev, "xtr");
+	if (irq < 0)
+		return -ENODEV;
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					ocelot_xtr_irq_handler, IRQF_ONESHOT,
+					"frame extraction", ocelot);
+	if (err)
+		return err;
+
+	regmap_field_write(ocelot->regfields[SYS_RESET_CFG_MEM_INIT], 1);
+	regmap_field_write(ocelot->regfields[SYS_RESET_CFG_MEM_ENA], 1);
+
+	do {
+		msleep(1);
+		regmap_field_read(ocelot->regfields[SYS_RESET_CFG_MEM_INIT],
+				  &val);
+	} while (val);
+
+	regmap_field_write(ocelot->regfields[SYS_RESET_CFG_MEM_ENA], 1);
+	regmap_field_write(ocelot->regfields[SYS_RESET_CFG_CORE_ENA], 1);
+
+	ocelot->num_cpu_ports = 1; /* 1 port on the switch, two groups */
+
+	ports = of_get_child_by_name(np, "ethernet-ports");
+	if (!ports) {
+		dev_err(&pdev->dev, "no ethernet-ports child node found\n");
+		return -ENODEV;
+	}
+
+	ocelot->num_phys_ports = of_get_child_count(ports);
+
+	ocelot->ports = devm_kcalloc(&pdev->dev, ocelot->num_phys_ports,
+				     sizeof(struct ocelot_port *), GFP_KERNEL);
+
+	INIT_LIST_HEAD(&ocelot->multicast);
+	ocelot_init(ocelot);
+
+	ocelot_rmw(ocelot, HSIO_HW_CFG_DEV1G_4_MODE |
+		     HSIO_HW_CFG_DEV1G_6_MODE |
+		     HSIO_HW_CFG_DEV1G_9_MODE,
+		     HSIO_HW_CFG_DEV1G_4_MODE |
+		     HSIO_HW_CFG_DEV1G_6_MODE |
+		     HSIO_HW_CFG_DEV1G_9_MODE,
+		     HSIO_HW_CFG);
+
+	for_each_available_child_of_node(ports, portnp) {
+		struct device_node *phy_node;
+		struct phy_device *phy;
+		struct resource *res;
+		void __iomem *regs;
+		char res_name[8];
+		u32 port;
+
+		if (of_property_read_u32(portnp, "reg", &port))
+			continue;
+
+		snprintf(res_name, sizeof(res_name), "port%d", port);
+
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						   res_name);
+		regs = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(regs))
+			continue;
+
+		phy_node = of_parse_phandle(portnp, "phy-handle", 0);
+		if (!phy_node)
+			continue;
+
+		phy = of_phy_find_device(phy_node);
+		if (!phy)
+			continue;
+
+		err = ocelot_probe_port(ocelot, port, regs, phy);
+		if (err) {
+			dev_err(&pdev->dev, "failed to probe ports\n");
+			goto err_probe_ports;
+		}
+	}
+
+	register_netdevice_notifier(&ocelot_netdevice_nb);
+
+	dev_info(&pdev->dev, "Ocelot switch probed\n");
+
+	return 0;
+
+err_probe_ports:
+	return err;
+}
+
+static int mscc_ocelot_remove(struct platform_device *pdev)
+{
+	struct ocelot *ocelot = platform_get_drvdata(pdev);
+
+	ocelot_deinit(ocelot);
+	unregister_netdevice_notifier(&ocelot_netdevice_nb);
+
+	return 0;
+}
+
+static struct platform_driver mscc_ocelot_driver = {
+	.probe = mscc_ocelot_probe,
+	.remove = mscc_ocelot_remove,
+	.driver = {
+		.name = "ocelot-switch",
+		.of_match_table = mscc_ocelot_match,
+	},
+};
+
+module_platform_driver(mscc_ocelot_driver);
+
+MODULE_DESCRIPTION("Microsemi Ocelot switch driver");
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
+MODULE_LICENSE("Dual MIT/GPL");