/*
 * include/net/dsa.h - Driver for Distributed Switch Architecture 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.
 */

#ifndef __LINUX_NET_DSA_H
#define __LINUX_NET_DSA_H

#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>

#define DSA_MAX_SWITCHES        4
#define DSA_MAX_PORTS           12

struct dsa_chip_data {
        /*
         * How to access the switch configuration registers.
         */
        struct device   *mii_bus;
        int             sw_addr;

        /*
         * The names of the switch's ports.  Use "cpu" to
         * designate the switch port that the cpu is connected to,
         * "dsa" to indicate that this port is a DSA link to
         * another switch, NULL to indicate the port is unused,
         * or any other string to indicate this is a physical port.
         */
        char            *port_names[DSA_MAX_PORTS];

        /*
         * An array (with nr_chips elements) of which element [a]
         * indicates which port on this switch should be used to
         * send packets to that are destined for switch a.  Can be
         * NULL if there is only one switch chip.
         */
        s8              *rtable;
};

struct dsa_platform_data {
        /*
         * Reference to a Linux network interface that connects
         * to the root switch chip of the tree.
         */
        struct device   *netdev;

        /*
         * Info structs describing each of the switch chips
         * connected via this network interface.
         */
        int             nr_chips;
        struct dsa_chip_data    *chip;
};

struct dsa_switch_tree {
        /*
         * Configuration data for the platform device that owns
         * this dsa switch tree instance.
         */
        struct dsa_platform_data        *pd;

        /*
         * Reference to network device to use, and which tagging
         * protocol to use.
         */
        struct net_device       *master_netdev;
        __be16                  tag_protocol;

        /*
         * The switch and port to which the CPU is attached.
         */
        s8                      cpu_switch;
        s8                      cpu_port;

        /*
         * Link state polling.
         */
        int                     link_poll_needed;
        struct work_struct      link_poll_work;
        struct timer_list       link_poll_timer;

        /*
         * Data for the individual switch chips.
         */
        struct dsa_switch       *ds[DSA_MAX_SWITCHES];
};

struct dsa_switch {
        /*
         * Parent switch tree, and switch index.
         */
        struct dsa_switch_tree  *dst;
        int                     index;

        /*
         * Configuration data for this switch.
         */
        struct dsa_chip_data    *pd;

        /*
         * The used switch driver.
         */
        struct dsa_switch_driver        *drv;

        /*
         * Reference to mii bus to use.
         */
        struct mii_bus          *master_mii_bus;

        /*
         * Slave mii_bus and devices for the individual ports.
         */
        u32                     dsa_port_mask;
        u32                     phys_port_mask;
        struct mii_bus          *slave_mii_bus;
        struct net_device       *ports[DSA_MAX_PORTS];
};

static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
{
        return !!(ds->index == ds->dst->cpu_switch && p == ds->dst->cpu_port);
}

static inline u8 dsa_upstream_port(struct dsa_switch *ds)
{
        struct dsa_switch_tree *dst = ds->dst;

        /*
         * If this is the root switch (i.e. the switch that connects
         * to the CPU), return the cpu port number on this switch.
         * Else return the (DSA) port number that connects to the
         * switch that is one hop closer to the cpu.
         */
        if (dst->cpu_switch == ds->index)
                return dst->cpu_port;
        else
                return ds->pd->rtable[dst->cpu_switch];
}

struct dsa_switch_driver {
        struct list_head        list;

        __be16                  tag_protocol;
        int                     priv_size;

        /*
         * Probing and setup.
         */
        char    *(*probe)(struct mii_bus *bus, int sw_addr);
        int     (*setup)(struct dsa_switch *ds);
        int     (*set_addr)(struct dsa_switch *ds, u8 *addr);

        /*
         * Access to the switch's PHY registers.
         */
        int     (*phy_read)(struct dsa_switch *ds, int port, int regnum);
        int     (*phy_write)(struct dsa_switch *ds, int port,
                             int regnum, u16 val);

        /*
         * Link state polling and IRQ handling.
         */
        void    (*poll_link)(struct dsa_switch *ds);

        /*
         * ethtool hardware statistics.
         */
        void    (*get_strings)(struct dsa_switch *ds, int port, uint8_t *data);
        void    (*get_ethtool_stats)(struct dsa_switch *ds,
                                     int port, uint64_t *data);
        int     (*get_sset_count)(struct dsa_switch *ds);
};

void register_switch_driver(struct dsa_switch_driver *type);
void unregister_switch_driver(struct dsa_switch_driver *type);

/*
 * The original DSA tag format and some other tag formats have no
 * ethertype, which means that we need to add a little hack to the
 * networking receive path to make sure that received frames get
 * the right ->protocol assigned to them when one of those tag
 * formats is in use.
 */
static inline bool dsa_uses_dsa_tags(struct dsa_switch_tree *dst)
{
        return !!(dst->tag_protocol == htons(ETH_P_DSA));
}

static inline bool dsa_uses_trailer_tags(struct dsa_switch_tree *dst)
{
        return !!(dst->tag_protocol == htons(ETH_P_TRAILER));
}

#endif