/*
   * 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