kernel-ark/net/dsa/mv88e6060.c
Lennert Buytenhek e84665c9cb dsa: add switch chip cascading support
The initial version of the DSA driver only supported a single switch
chip per network interface, while DSA-capable switch chips can be
interconnected to form a tree of switch chips.  This patch adds support
for multiple switch chips on a network interface.

An example topology for a 16-port device with an embedded CPU is as
follows:

	+-----+          +--------+       +--------+
	|     |eth0    10| switch |9    10| switch |
	| CPU +----------+        +-------+        |
	|     |          | chip 0 |       | chip 1 |
	+-----+          +---++---+       +---++---+
	                     ||               ||
	                     ||               ||
	                     ||1000baseT      ||1000baseT
	                     ||ports 1-8      ||ports 9-16

This requires a couple of interdependent changes in the DSA layer:

- The dsa platform driver data needs to be extended: there is still
  only one netdevice per DSA driver instance (eth0 in the example
  above), but each of the switch chips in the tree needs its own
  mii_bus device pointer, MII management bus address, and port name
  array. (include/net/dsa.h)  The existing in-tree dsa users need
  some small changes to deal with this. (arch/arm)

- The DSA and Ethertype DSA tagging modules need to be extended to
  use the DSA device ID field on receive and demultiplex the packet
  accordingly, and fill in the DSA device ID field on transmit
  according to which switch chip the packet is heading to.
  (net/dsa/tag_{dsa,edsa}.c)

- The concept of "CPU port", which is the switch chip port that the
  CPU is connected to (port 10 on switch chip 0 in the example), needs
  to be extended with the concept of "upstream port", which is the
  port on the switch chip that will bring us one hop closer to the CPU
  (port 10 for both switch chips in the example above).

- The dsa platform data needs to specify which ports on which switch
  chips are links to other switch chips, so that we can enable DSA
  tagging mode on them.  (For inter-switch links, we always use
  non-EtherType DSA tagging, since it has lower overhead.  The CPU
  link uses dsa or edsa tagging depending on what the 'root' switch
  chip supports.)  This is done by specifying "dsa" for the given
  port in the port array.

- The dsa platform data needs to be extended with information on via
  which port to reach any given switch chip from any given switch chip.
  This info is specified via the per-switch chip data struct ->rtable[]
  array, which gives the nexthop ports for each of the other switches
  in the tree.

For the example topology above, the dsa platform data would look
something like this:

	static struct dsa_chip_data sw[2] = {
		{
			.mii_bus	= &foo,
			.sw_addr	= 1,
			.port_names[0]	= "p1",
			.port_names[1]	= "p2",
			.port_names[2]	= "p3",
			.port_names[3]	= "p4",
			.port_names[4]	= "p5",
			.port_names[5]	= "p6",
			.port_names[6]	= "p7",
			.port_names[7]	= "p8",
			.port_names[9]	= "dsa",
			.port_names[10]	= "cpu",
			.rtable		= (s8 []){ -1, 9, },
		}, {
			.mii_bus	= &foo,
			.sw_addr	= 2,
			.port_names[0]	= "p9",
			.port_names[1]	= "p10",
			.port_names[2]	= "p11",
			.port_names[3]	= "p12",
			.port_names[4]	= "p13",
			.port_names[5]	= "p14",
			.port_names[6]	= "p15",
			.port_names[7]	= "p16",
			.port_names[10]	= "dsa",
			.rtable		= (s8 []){ 10, -1, },
		},
	},

	static struct dsa_platform_data pd = {
		.netdev		= &foo,
		.nr_switches	= 2,
		.sw		= sw,
	};

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Gary Thomas <gary@mlbassoc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-21 19:06:54 -07:00

288 lines
5.9 KiB
C

/*
* net/dsa/mv88e6060.c - Driver for Marvell 88e6060 switch chips
* Copyright (c) 2008-2009 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"
#define REG_PORT(p) (8 + (p))
#define REG_GLOBAL 0x0f
static int reg_read(struct dsa_switch *ds, int addr, int reg)
{
return mdiobus_read(ds->master_mii_bus, addr, reg);
}
#define REG_READ(addr, reg) \
({ \
int __ret; \
\
__ret = reg_read(ds, addr, reg); \
if (__ret < 0) \
return __ret; \
__ret; \
})
static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
{
return mdiobus_write(ds->master_mii_bus, addr, reg, val);
}
#define REG_WRITE(addr, reg, val) \
({ \
int __ret; \
\
__ret = reg_write(ds, addr, reg, val); \
if (__ret < 0) \
return __ret; \
})
static char *mv88e6060_probe(struct mii_bus *bus, int sw_addr)
{
int ret;
ret = mdiobus_read(bus, REG_PORT(0), 0x03);
if (ret >= 0) {
ret &= 0xfff0;
if (ret == 0x0600)
return "Marvell 88E6060";
}
return NULL;
}
static int mv88e6060_switch_reset(struct dsa_switch *ds)
{
int i;
int ret;
/*
* Set all ports to the disabled state.
*/
for (i = 0; i < 6; 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, 0x0a, 0xa130);
/*
* Wait up to one second for reset to complete.
*/
for (i = 0; i < 1000; i++) {
ret = REG_READ(REG_GLOBAL, 0x00);
if ((ret & 0x8000) == 0x0000)
break;
msleep(1);
}
if (i == 1000)
return -ETIMEDOUT;
return 0;
}
static int mv88e6060_setup_global(struct dsa_switch *ds)
{
/*
* Disable discarding of frames with excessive collisions,
* set the maximum frame size to 1536 bytes, and mask all
* interrupt sources.
*/
REG_WRITE(REG_GLOBAL, 0x04, 0x0800);
/*
* Enable automatic address learning, set the address
* database size to 1024 entries, and set the default aging
* time to 5 minutes.
*/
REG_WRITE(REG_GLOBAL, 0x0a, 0x2130);
return 0;
}
static int mv88e6060_setup_port(struct dsa_switch *ds, int p)
{
int addr = REG_PORT(p);
/*
* Do not force flow control, disable Ingress and Egress
* Header tagging, disable VLAN tunneling, and set the port
* state to Forwarding. Additionally, if this is the CPU
* port, enable Ingress and Egress Trailer tagging mode.
*/
REG_WRITE(addr, 0x04, dsa_is_cpu_port(ds, p) ? 0x4103 : 0x0003);
/*
* 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) |
(dsa_is_cpu_port(ds, p) ?
ds->phys_port_mask :
(1 << ds->dst->cpu_port)));
/*
* 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);
return 0;
}
static int mv88e6060_setup(struct dsa_switch *ds)
{
int i;
int ret;
ret = mv88e6060_switch_reset(ds);
if (ret < 0)
return ret;
/* @@@ initialise atu */
ret = mv88e6060_setup_global(ds);
if (ret < 0)
return ret;
for (i = 0; i < 6; i++) {
ret = mv88e6060_setup_port(ds, i);
if (ret < 0)
return ret;
}
return 0;
}
static int mv88e6060_set_addr(struct dsa_switch *ds, u8 *addr)
{
REG_WRITE(REG_GLOBAL, 0x01, (addr[0] << 8) | addr[1]);
REG_WRITE(REG_GLOBAL, 0x02, (addr[2] << 8) | addr[3]);
REG_WRITE(REG_GLOBAL, 0x03, (addr[4] << 8) | addr[5]);
return 0;
}
static int mv88e6060_port_to_phy_addr(int port)
{
if (port >= 0 && port <= 5)
return port;
return -1;
}
static int mv88e6060_phy_read(struct dsa_switch *ds, int port, int regnum)
{
int addr;
addr = mv88e6060_port_to_phy_addr(port);
if (addr == -1)
return 0xffff;
return reg_read(ds, addr, regnum);
}
static int
mv88e6060_phy_write(struct dsa_switch *ds, int port, int regnum, u16 val)
{
int addr;
addr = mv88e6060_port_to_phy_addr(port);
if (addr == -1)
return 0xffff;
return reg_write(ds, addr, regnum, val);
}
static void mv88e6060_poll_link(struct dsa_switch *ds)
{
int i;
for (i = 0; i < DSA_MAX_PORTS; i++) {
struct net_device *dev;
int uninitialized_var(port_status);
int link;
int speed;
int duplex;
int fc;
dev = ds->ports[i];
if (dev == NULL)
continue;
link = 0;
if (dev->flags & IFF_UP) {
port_status = reg_read(ds, REG_PORT(i), 0x00);
if (port_status < 0)
continue;
link = !!(port_status & 0x1000);
}
if (!link) {
if (netif_carrier_ok(dev)) {
printk(KERN_INFO "%s: link down\n", dev->name);
netif_carrier_off(dev);
}
continue;
}
speed = (port_status & 0x0100) ? 100 : 10;
duplex = (port_status & 0x0200) ? 1 : 0;
fc = ((port_status & 0xc000) == 0xc000) ? 1 : 0;
if (!netif_carrier_ok(dev)) {
printk(KERN_INFO "%s: link up, %d Mb/s, %s duplex, "
"flow control %sabled\n", dev->name,
speed, duplex ? "full" : "half",
fc ? "en" : "dis");
netif_carrier_on(dev);
}
}
}
static struct dsa_switch_driver mv88e6060_switch_driver = {
.tag_protocol = htons(ETH_P_TRAILER),
.probe = mv88e6060_probe,
.setup = mv88e6060_setup,
.set_addr = mv88e6060_set_addr,
.phy_read = mv88e6060_phy_read,
.phy_write = mv88e6060_phy_write,
.poll_link = mv88e6060_poll_link,
};
static int __init mv88e6060_init(void)
{
register_switch_driver(&mv88e6060_switch_driver);
return 0;
}
module_init(mv88e6060_init);
static void __exit mv88e6060_cleanup(void)
{
unregister_switch_driver(&mv88e6060_switch_driver);
}
module_exit(mv88e6060_cleanup);