net: Distributed Switch Architecture protocol support

Distributed Switch Architecture is a protocol for managing hardware
switch chips.  It consists of a set of MII management registers and
commands to configure the switch, and an ethernet header format to
signal which of the ports of the switch a packet was received from
or is intended to be sent to.

The switches that this driver supports are typically embedded in
access points and routers, and a typical setup with a DSA switch
looks something like this:

	+-----------+       +-----------+
	|           | RGMII |           |
	|           +-------+           +------ 1000baseT MDI ("WAN")
	|           |       |  6-port   +------ 1000baseT MDI ("LAN1")
	|    CPU    |       |  ethernet +------ 1000baseT MDI ("LAN2")
	|           |MIImgmt|  switch   +------ 1000baseT MDI ("LAN3")
	|           +-------+  w/5 PHYs +------ 1000baseT MDI ("LAN4")
	|           |       |           |
	+-----------+       +-----------+

The switch driver presents each port on the switch as a separate
network interface to Linux, polls the switch to maintain software
link state of those ports, forwards MII management interface
accesses to those network interfaces (e.g. as done by ethtool) to
the switch, and exposes the switch's hardware statistics counters
via the appropriate Linux kernel interfaces.

This initial patch supports the MII management interface register
layout of the Marvell 88E6123, 88E6161 and 88E6165 switch chips, and
supports the "Ethertype DSA" packet tagging format.

(There is no officially registered ethertype for the Ethertype DSA
packet format, so we just grab a random one.  The ethertype to use
is programmed into the switch, and the switch driver uses the value
of ETH_P_EDSA for this, so this define can be changed at any time in
the future if the one we chose is allocated to another protocol or
if Ethertype DSA gets its own officially registered ethertype, and
everything will continue to work.)

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Nicolas Pitre <nico@marvell.com>
Tested-by: Byron Bradley <byron.bbradley@gmail.com>
Tested-by: Tim Ellis <tim.ellis@mac.com>
Tested-by: Peter van Valderen <linux@ddcrew.com>
Tested-by: Dirk Teurlings <dirk@upexia.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 417 insertions, 0 deletions

diff --git a/net/dsa/mv88e6123_61_65.c b/net/dsa/mv88e6123_61_65.c
new file mode 100644
index 00000000000..147818cc706
--- /dev/null
+++ b/net/dsa/mv88e6123_61_65.c
@@ -0,0 +1,417 @@
+/*
+ * net/dsa/mv88e6123_61_65.c - Marvell 88e6123/6161/6165 switch chip support
+ * Copyright (c) 2008 Marvell Semiconductor
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+#include "dsa_priv.h"
+#include "mv88e6xxx.h"
+
+static char *mv88e6123_61_65_probe(struct mii_bus *bus, int sw_addr)
+{
+	int ret;
+
+	ret = __mv88e6xxx_reg_read(bus, sw_addr, REG_PORT(0), 0x03);
+	if (ret >= 0) {
+		ret &= 0xfff0;
+		if (ret == 0x1210)
+			return "Marvell 88E6123";
+		if (ret == 0x1610)
+			return "Marvell 88E6161";
+		if (ret == 0x1650)
+			return "Marvell 88E6165";
+	}
+
+	return NULL;
+}
+
+static int mv88e6123_61_65_switch_reset(struct dsa_switch *ds)
+{
+	int i;
+	int ret;
+
+	/*
+	 * Set all ports to the disabled state.
+	 */
+	for (i = 0; i < 8; i++) {
+		ret = REG_READ(REG_PORT(i), 0x04);
+		REG_WRITE(REG_PORT(i), 0x04, ret & 0xfffc);
+	}
+
+	/*
+	 * Wait for transmit queues to drain.
+	 */
+	msleep(2);
+
+	/*
+	 * Reset the switch.
+	 */
+	REG_WRITE(REG_GLOBAL, 0x04, 0xc400);
+
+	/*
+	 * Wait up to one second for reset to complete.
+	 */
+	for (i = 0; i < 1000; i++) {
+		ret = REG_READ(REG_GLOBAL, 0x00);
+		if ((ret & 0xc800) == 0xc800)
+			break;
+
+		msleep(1);
+	}
+	if (i == 1000)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int mv88e6123_61_65_setup_global(struct dsa_switch *ds)
+{
+	int ret;
+	int i;
+
+	/*
+	 * Disable the PHY polling unit (since there won't be any
+	 * external PHYs to poll), don't discard packets with
+	 * excessive collisions, and mask all interrupt sources.
+	 */
+	REG_WRITE(REG_GLOBAL, 0x04, 0x0000);
+
+	/*
+	 * Set the default address aging time to 5 minutes, and
+	 * enable address learn messages to be sent to all message
+	 * ports.
+	 */
+	REG_WRITE(REG_GLOBAL, 0x0a, 0x0148);
+
+	/*
+	 * Configure the priority mapping registers.
+	 */
+	ret = mv88e6xxx_config_prio(ds);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Configure the cpu port, and configure the cpu port as the
+	 * port to which ingress and egress monitor frames are to be
+	 * sent.
+	 */
+	REG_WRITE(REG_GLOBAL, 0x1a, (ds->cpu_port * 0x1110));
+
+	/*
+	 * Disable remote management for now, and set the switch's
+	 * DSA device number to zero.
+	 */
+	REG_WRITE(REG_GLOBAL, 0x1c, 0x0000);
+
+	/*
+	 * Send all frames with destination addresses matching
+	 * 01:80:c2:00:00:2x to the CPU port.
+	 */
+	REG_WRITE(REG_GLOBAL2, 0x02, 0xffff);
+
+	/*
+	 * Send all frames with destination addresses matching
+	 * 01:80:c2:00:00:0x to the CPU port.
+	 */
+	REG_WRITE(REG_GLOBAL2, 0x03, 0xffff);
+
+	/*
+	 * Disable the loopback filter, disable flow control
+	 * messages, disable flood broadcast override, disable
+	 * removing of provider tags, disable ATU age violation
+	 * interrupts, disable tag flow control, force flow
+	 * control priority to the highest, and send all special
+	 * multicast frames to the CPU at the highest priority.
+	 */
+	REG_WRITE(REG_GLOBAL2, 0x05, 0x00ff);
+
+	/*
+	 * Map all DSA device IDs to the CPU port.
+	 */
+	for (i = 0; i < 32; i++)
+		REG_WRITE(REG_GLOBAL2, 0x06, 0x8000 | (i << 8) | ds->cpu_port);
+
+	/*
+	 * Clear all trunk masks.
+	 */
+	for (i = 0; i < 8; i++)
+		REG_WRITE(REG_GLOBAL2, 0x07, 0x8000 | (i << 12) | 0xff);
+
+	/*
+	 * Clear all trunk mappings.
+	 */
+	for (i = 0; i < 16; i++)
+		REG_WRITE(REG_GLOBAL2, 0x08, 0x8000 | (i << 11));
+
+	/*
+	 * Disable ingress rate limiting by resetting all ingress
+	 * rate limit registers to their initial state.
+	 */
+	for (i = 0; i < 6; i++)
+		REG_WRITE(REG_GLOBAL2, 0x09, 0x9000 | (i << 8));
+
+	/*
+	 * Initialise cross-chip port VLAN table to reset defaults.
+	 */
+	REG_WRITE(REG_GLOBAL2, 0x0b, 0x9000);
+
+	/*
+	 * Clear the priority override table.
+	 */
+	for (i = 0; i < 16; i++)
+		REG_WRITE(REG_GLOBAL2, 0x0f, 0x8000 | (i << 8));
+
+	/* @@@ initialise AVB (22/23) watchdog (27) sdet (29) registers */
+
+	return 0;
+}
+
+static int mv88e6123_61_65_setup_port(struct dsa_switch *ds, int p)
+{
+	int addr = REG_PORT(p);
+
+	/*
+	 * MAC Forcing register: don't force link, speed, duplex
+	 * or flow control state to any particular values.
+	 */
+	REG_WRITE(addr, 0x01, 0x0003);
+
+	/*
+	 * Do not limit the period of time that this port can be
+	 * paused for by the remote end or the period of time that
+	 * this port can pause the remote end.
+	 */
+	REG_WRITE(addr, 0x02, 0x0000);
+
+	/*
+	 * Port Control: disable Drop-on-Unlock, disable Drop-on-Lock,
+	 * configure the EDSA tagging mode if this is the CPU port,
+	 * disable Header mode, enable IGMP/MLD snooping, disable VLAN
+	 * tunneling, determine priority by looking at 802.1p and IP
+	 * priority fields (IP prio has precedence), and set STP state
+	 * to Forwarding.  Finally, if this is the CPU port, additionally
+	 * enable forwarding of unknown unicast and multicast addresses.
+	 */
+	REG_WRITE(addr, 0x04,
+			(p == ds->cpu_port) ? 0x373f : 0x0433);
+
+	/*
+	 * Port Control 1: disable trunking.  Also, if this is the
+	 * CPU port, enable learn messages to be sent to this port.
+	 */
+	REG_WRITE(addr, 0x05, (p == ds->cpu_port) ? 0x8000 : 0x0000);
+
+	/*
+	 * Port based VLAN map: give each port its own address
+	 * database, allow the CPU port to talk to each of the 'real'
+	 * ports, and allow each of the 'real' ports to only talk to
+	 * the CPU port.
+	 */
+	REG_WRITE(addr, 0x06,
+			((p & 0xf) << 12) |
+			 ((p == ds->cpu_port) ?
+				ds->valid_port_mask :
+				(1 << ds->cpu_port)));
+
+	/*
+	 * Default VLAN ID and priority: don't set a default VLAN
+	 * ID, and set the default packet priority to zero.
+	 */
+	REG_WRITE(addr, 0x07, 0x0000);
+
+	/*
+	 * Port Control 2: don't force a good FCS, set the maximum
+	 * frame size to 10240 bytes, don't let the switch add or
+	 * strip 802.1q tags, don't discard tagged or untagged frames
+	 * on this port, do a destination address lookup on all
+	 * received packets as usual, disable ARP mirroring and don't
+	 * send a copy of all transmitted/received frames on this port
+	 * to the CPU.
+	 */
+	REG_WRITE(addr, 0x08, 0x2080);
+
+	/*
+	 * Egress rate control: disable egress rate control.
+	 */
+	REG_WRITE(addr, 0x09, 0x0001);
+
+	/*
+	 * Egress rate control 2: disable egress rate control.
+	 */
+	REG_WRITE(addr, 0x0a, 0x0000);
+
+	/*
+	 * Port Association Vector: when learning source addresses
+	 * of packets, add the address to the address database using
+	 * a port bitmap that has only the bit for this port set and
+	 * the other bits clear.
+	 */
+	REG_WRITE(addr, 0x0b, 1 << p);
+
+	/*
+	 * Port ATU control: disable limiting the number of address
+	 * database entries that this port is allowed to use.
+	 */
+	REG_WRITE(addr, 0x0c, 0x0000);
+
+	/*
+	 * Priorit Override: disable DA, SA and VTU priority override.
+	 */
+	REG_WRITE(addr, 0x0d, 0x0000);
+
+	/*
+	 * Port Ethertype: use the Ethertype DSA Ethertype value.
+	 */
+	REG_WRITE(addr, 0x0f, ETH_P_EDSA);
+
+	/*
+	 * Tag Remap: use an identity 802.1p prio -> switch prio
+	 * mapping.
+	 */
+	REG_WRITE(addr, 0x18, 0x3210);
+
+	/*
+	 * Tag Remap 2: use an identity 802.1p prio -> switch prio
+	 * mapping.
+	 */
+	REG_WRITE(addr, 0x19, 0x7654);
+
+	return 0;
+}
+
+static int mv88e6123_61_65_setup(struct dsa_switch *ds)
+{
+	struct mv88e6xxx_priv_state *ps = (void *)(ds + 1);
+	int i;
+	int ret;
+
+	mutex_init(&ps->smi_mutex);
+	mutex_init(&ps->stats_mutex);
+
+	ret = mv88e6123_61_65_switch_reset(ds);
+	if (ret < 0)
+		return ret;
+
+	/* @@@ initialise vtu and atu */
+
+	ret = mv88e6123_61_65_setup_global(ds);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < 6; i++) {
+		ret = mv88e6123_61_65_setup_port(ds, i);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int mv88e6123_61_65_port_to_phy_addr(int port)
+{
+	if (port >= 0 && port <= 4)
+		return port;
+	return -1;
+}
+
+static int
+mv88e6123_61_65_phy_read(struct dsa_switch *ds, int port, int regnum)
+{
+	int addr = mv88e6123_61_65_port_to_phy_addr(port);
+	return mv88e6xxx_phy_read(ds, addr, regnum);
+}
+
+static int
+mv88e6123_61_65_phy_write(struct dsa_switch *ds,
+			      int port, int regnum, u16 val)
+{
+	int addr = mv88e6123_61_65_port_to_phy_addr(port);
+	return mv88e6xxx_phy_write(ds, addr, regnum, val);
+}
+
+static struct mv88e6xxx_hw_stat mv88e6123_61_65_hw_stats[] = {
+	{ "in_good_octets", 8, 0x00, },
+	{ "in_bad_octets", 4, 0x02, },
+	{ "in_unicast", 4, 0x04, },
+	{ "in_broadcasts", 4, 0x06, },
+	{ "in_multicasts", 4, 0x07, },
+	{ "in_pause", 4, 0x16, },
+	{ "in_undersize", 4, 0x18, },
+	{ "in_fragments", 4, 0x19, },
+	{ "in_oversize", 4, 0x1a, },
+	{ "in_jabber", 4, 0x1b, },
+	{ "in_rx_error", 4, 0x1c, },
+	{ "in_fcs_error", 4, 0x1d, },
+	{ "out_octets", 8, 0x0e, },
+	{ "out_unicast", 4, 0x10, },
+	{ "out_broadcasts", 4, 0x13, },
+	{ "out_multicasts", 4, 0x12, },
+	{ "out_pause", 4, 0x15, },
+	{ "excessive", 4, 0x11, },
+	{ "collisions", 4, 0x1e, },
+	{ "deferred", 4, 0x05, },
+	{ "single", 4, 0x14, },
+	{ "multiple", 4, 0x17, },
+	{ "out_fcs_error", 4, 0x03, },
+	{ "late", 4, 0x1f, },
+	{ "hist_64bytes", 4, 0x08, },
+	{ "hist_65_127bytes", 4, 0x09, },
+	{ "hist_128_255bytes", 4, 0x0a, },
+	{ "hist_256_511bytes", 4, 0x0b, },
+	{ "hist_512_1023bytes", 4, 0x0c, },
+	{ "hist_1024_max_bytes", 4, 0x0d, },
+};
+
+static void
+mv88e6123_61_65_get_strings(struct dsa_switch *ds, int port, uint8_t *data)
+{
+	mv88e6xxx_get_strings(ds, ARRAY_SIZE(mv88e6123_61_65_hw_stats),
+			      mv88e6123_61_65_hw_stats, port, data);
+}
+
+static void
+mv88e6123_61_65_get_ethtool_stats(struct dsa_switch *ds,
+				  int port, uint64_t *data)
+{
+	mv88e6xxx_get_ethtool_stats(ds, ARRAY_SIZE(mv88e6123_61_65_hw_stats),
+				    mv88e6123_61_65_hw_stats, port, data);
+}
+
+static int mv88e6123_61_65_get_sset_count(struct dsa_switch *ds)
+{
+	return ARRAY_SIZE(mv88e6123_61_65_hw_stats);
+}
+
+static struct dsa_switch_driver mv88e6123_61_65_switch_driver = {
+	.tag_protocol		= __constant_htons(ETH_P_EDSA),
+	.priv_size		= sizeof(struct mv88e6xxx_priv_state),
+	.probe			= mv88e6123_61_65_probe,
+	.setup			= mv88e6123_61_65_setup,
+	.set_addr		= mv88e6xxx_set_addr_indirect,
+	.phy_read		= mv88e6123_61_65_phy_read,
+	.phy_write		= mv88e6123_61_65_phy_write,
+	.poll_link		= mv88e6xxx_poll_link,
+	.get_strings		= mv88e6123_61_65_get_strings,
+	.get_ethtool_stats	= mv88e6123_61_65_get_ethtool_stats,
+	.get_sset_count		= mv88e6123_61_65_get_sset_count,
+};
+
+int __init mv88e6123_61_65_init(void)
+{
+	register_switch_driver(&mv88e6123_61_65_switch_driver);
+	return 0;
+}
+module_init(mv88e6123_61_65_init);
+
+void __exit mv88e6123_61_65_cleanup(void)
+{
+	unregister_switch_driver(&mv88e6123_61_65_switch_driver);
+}
+module_exit(mv88e6123_61_65_cleanup);