/*
 * 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/delay.h>
#include <linux/etherdevice.h>
#include <linux/jiffies.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <net/dsa.h>
#include "mv88e6060.h"

static int reg_read(struct dsa_switch *ds, int addr, int reg)
{
        struct mv88e6060_priv *priv = ds->priv;

        return mdiobus_read_nested(priv->bus, priv->sw_addr + 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)
{
        struct mv88e6060_priv *priv = ds->priv;

        return mdiobus_write_nested(priv->bus, priv->sw_addr + addr, reg, val);
}

#define REG_WRITE(addr, reg, val)                               \
        ({                                                      \
                int __ret;                                      \
                                                                \
                __ret = reg_write(ds, addr, reg, val);          \
                if (__ret < 0)                                  \
                        return __ret;                           \
        })

static const char *mv88e6060_get_name(struct mii_bus *bus, int sw_addr)
{
        int ret;

        ret = mdiobus_read(bus, sw_addr + REG_PORT(0), PORT_SWITCH_ID);
        if (ret >= 0) {
                if (ret == PORT_SWITCH_ID_6060)
                        return "Marvell 88E6060 (A0)";
                if (ret == PORT_SWITCH_ID_6060_R1 ||
                    ret == PORT_SWITCH_ID_6060_R2)
                        return "Marvell 88E6060 (B0)";
                if ((ret & PORT_SWITCH_ID_6060_MASK) == PORT_SWITCH_ID_6060)
                        return "Marvell 88E6060";
        }

        return NULL;
}

static enum dsa_tag_protocol mv88e6060_get_tag_protocol(struct dsa_switch *ds,
                                                        int port)
{
        return DSA_TAG_PROTO_TRAILER;
}

static const char *mv88e6060_drv_probe(struct device *dsa_dev,
                                       struct device *host_dev, int sw_addr,
                                       void **_priv)
{
        struct mii_bus *bus = dsa_host_dev_to_mii_bus(host_dev);
        struct mv88e6060_priv *priv;
        const char *name;

        name = mv88e6060_get_name(bus, sw_addr);
        if (name) {
                priv = devm_kzalloc(dsa_dev, sizeof(*priv), GFP_KERNEL);
                if (!priv)
                        return NULL;
                *_priv = priv;
                priv->bus = bus;
                priv->sw_addr = sw_addr;
        }

        return name;
}

static int mv88e6060_switch_reset(struct dsa_switch *ds)
{
        int i;
        int ret;
        unsigned long timeout;

        /* Set all ports to the disabled state. */
        for (i = 0; i < MV88E6060_PORTS; i++) {
                ret = REG_READ(REG_PORT(i), PORT_CONTROL);
                REG_WRITE(REG_PORT(i), PORT_CONTROL,
                          ret & ~PORT_CONTROL_STATE_MASK);
        }

        /* Wait for transmit queues to drain. */
        usleep_range(2000, 4000);

        /* Reset the switch. */
        REG_WRITE(REG_GLOBAL, GLOBAL_ATU_CONTROL,
                  GLOBAL_ATU_CONTROL_SWRESET |
                  GLOBAL_ATU_CONTROL_ATUSIZE_1024 |
                  GLOBAL_ATU_CONTROL_ATE_AGE_5MIN);

        /* Wait up to one second for reset to complete. */
        timeout = jiffies + 1 * HZ;
        while (time_before(jiffies, timeout)) {
                ret = REG_READ(REG_GLOBAL, GLOBAL_STATUS);
                if (ret & GLOBAL_STATUS_INIT_READY)
                        break;

                usleep_range(1000, 2000);
        }
        if (time_after(jiffies, timeout))
                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, GLOBAL_CONTROL, GLOBAL_CONTROL_MAX_FRAME_1536);

        /* 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, GLOBAL_ATU_CONTROL,
                  GLOBAL_ATU_CONTROL_ATUSIZE_1024 |
                  GLOBAL_ATU_CONTROL_ATE_AGE_5MIN);

        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, PORT_CONTROL,
                  dsa_is_cpu_port(ds, p) ?
                        PORT_CONTROL_TRAILER |
                        PORT_CONTROL_INGRESS_MODE |
                        PORT_CONTROL_STATE_FORWARDING :
                        PORT_CONTROL_STATE_FORWARDING);

        /* 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, PORT_VLAN_MAP,
                  ((p & 0xf) << PORT_VLAN_MAP_DBNUM_SHIFT) |
                   (dsa_is_cpu_port(ds, p) ? dsa_user_ports(ds) :
                    BIT(dsa_to_port(ds, p)->cpu_dp->index)));

        /* 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, PORT_ASSOC_VECTOR, BIT(p));

        return 0;
}

static int mv88e6060_setup_addr(struct dsa_switch *ds)
{
        u8 addr[ETH_ALEN];
        u16 val;

        eth_random_addr(addr);

        val = addr[0] << 8 | addr[1];

        /* The multicast bit is always transmitted as a zero, so the switch uses
         * bit 8 for "DiffAddr", where 0 means all ports transmit the same SA.
         */
        val &= 0xfeff;

        REG_WRITE(REG_GLOBAL, GLOBAL_MAC_01, val);
        REG_WRITE(REG_GLOBAL, GLOBAL_MAC_23, (addr[2] << 8) | addr[3]);
        REG_WRITE(REG_GLOBAL, GLOBAL_MAC_45, (addr[4] << 8) | addr[5]);

        return 0;
}

static int mv88e6060_setup(struct dsa_switch *ds)
{
        int ret;
        int i;

        ret = mv88e6060_switch_reset(ds);
        if (ret < 0)
                return ret;

        /* @@@ initialise atu */

        ret = mv88e6060_setup_global(ds);
        if (ret < 0)
                return ret;

        ret = mv88e6060_setup_addr(ds);
        if (ret < 0)
                return ret;

        for (i = 0; i < MV88E6060_PORTS; i++) {
                ret = mv88e6060_setup_port(ds, i);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int mv88e6060_port_to_phy_addr(int port)
{
        if (port >= 0 && port < MV88E6060_PORTS)
                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 const struct dsa_switch_ops mv88e6060_switch_ops = {
        .get_tag_protocol = mv88e6060_get_tag_protocol,
        .probe          = mv88e6060_drv_probe,
        .setup          = mv88e6060_setup,
        .phy_read       = mv88e6060_phy_read,
        .phy_write      = mv88e6060_phy_write,
};

static struct dsa_switch_driver mv88e6060_switch_drv = {
        .ops            = &mv88e6060_switch_ops,
};

static int __init mv88e6060_init(void)
{
        register_switch_driver(&mv88e6060_switch_drv);
        return 0;
}
module_init(mv88e6060_init);

static void __exit mv88e6060_cleanup(void)
{
        unregister_switch_driver(&mv88e6060_switch_drv);
}
module_exit(mv88e6060_cleanup);

MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
MODULE_DESCRIPTION("Driver for Marvell 88E6060 ethernet switch chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mv88e6060");