/*

   * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>

   *

   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.

   */

  #ifndef __LINUX_W1_H
  #define __LINUX_W1_H
  
  #include <linux/device.h>

  /**
   * struct w1_reg_num - broken out slave device id
   *
   * @family: identifies the type of device
   * @id: along with family is the unique device id
   * @crc: checksum of the other bytes
   */

  struct w1_reg_num {

  #if defined(__LITTLE_ENDIAN_BITFIELD)

  	__u64	family:8,
  		id:48,
  		crc:8;

  #elif defined(__BIG_ENDIAN_BITFIELD)
  	__u64	crc:8,
  		id:48,
  		family:8;
  #else
  #error "Please fix <asm/byteorder.h>"
  #endif
  };
  
  #ifdef __KERNEL__

  #define W1_MAXNAMELEN		32

  
  #define W1_SEARCH		0xF0

  #define W1_ALARM_SEARCH		0xEC

  #define W1_CONVERT_TEMP		0x44
  #define W1_SKIP_ROM		0xCC

  #define W1_COPY_SCRATCHPAD	0x48
  #define W1_WRITE_SCRATCHPAD	0x4E

  #define W1_READ_SCRATCHPAD	0xBE
  #define W1_READ_ROM		0x33
  #define W1_READ_PSUPPLY		0xB4
  #define W1_MATCH_ROM		0x55

  #define W1_RESUME_CMD		0xA5

  /**
   * struct w1_slave - holds a single slave device on the bus
   *
   * @owner: Points to the one wire "wire" kernel module.
   * @name: Device id is ascii.
   * @w1_slave_entry: data for the linked list
   * @reg_num: the slave id in binary
   * @refcnt: reference count, delete when 0
   * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
   * @ttl: decrement per search this slave isn't found, deatch at 0
   * @master: bus which this slave is on
   * @family: module for device family type
   * @family_data: pointer for use by the family module
   * @dev: kernel device identifier

   * @hwmon: pointer to hwmon device

   *
   */

  struct w1_slave {

  	struct module		*owner;
  	unsigned char		name[W1_MAXNAMELEN];
  	struct list_head	w1_slave_entry;
  	struct w1_reg_num	reg_num;
  	atomic_t		refcnt;

  	int			ttl;

  	unsigned long		flags;

  
  	struct w1_master	*master;

  	struct w1_family	*family;

  	void			*family_data;

  	struct device		dev;

  	struct device		*hwmon;

  };

  typedef void (*w1_slave_found_callback)(struct w1_master *, u64);

  /**

   * struct w1_bus_master - operations available on a bus master
   *
   * @data: the first parameter in all the functions below
   *
   * @read_bit: Sample the line level @return the level read (0 or 1)
   *
   * @write_bit: Sets the line level
   *
   * @touch_bit: the lowest-level function for devices that really support the
   * 1-wire protocol.
   * touch_bit(0) = write-0 cycle
   * touch_bit(1) = write-1 / read cycle
   * @return the bit read (0 or 1)
   *
   * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
   * @return the byte read
   *
   * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
   *
   * @read_block: Same as a series of read_byte() calls
   * @return the number of bytes read
   *
   * @write_block: Same as a series of write_byte() calls
   *
   * @triplet: Combines two reads and a smart write for ROM searches
   * @return bit0=Id bit1=comp_id bit2=dir_taken
   *
   * @reset_bus: long write-0 with a read for the presence pulse detection
   * @return -1=Error, 0=Device present, 1=No device present
   *
   * @set_pullup: Put out a strong pull-up pulse of the specified duration.
   * @return -1=Error, 0=completed
   *
   * @search: Really nice hardware can handles the different types of ROM search
   * w1_master* is passed to the slave found callback.
   * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
   *

   * Note: read_bit and write_bit are very low level functions and should only
   * be used with hardware that doesn't really support 1-wire operations,
   * like a parallel/serial port.
   * Either define read_bit and write_bit OR define, at minimum, touch_bit and
   * reset_bus.

   *

   */

  struct w1_bus_master {

  	void		*data;

  	u8		(*read_bit)(void *);

  	void		(*write_bit)(void *, u8);

  	u8		(*touch_bit)(void *, u8);

  	u8		(*read_byte)(void *);

  	void		(*write_byte)(void *, u8);

  	u8		(*read_block)(void *, u8 *, int);

  	void		(*write_block)(void *, const u8 *, int);

  	u8		(*triplet)(void *, u8);

  	u8		(*reset_bus)(void *);

  	u8		(*set_pullup)(void *, int);

  	void		(*search)(void *, struct w1_master *,
  		u8, w1_slave_found_callback);

  };

  /**
   * enum w1_master_flags - bitfields used in w1_master.flags
   * @W1_ABORT_SEARCH: abort searching early on shutdown

   * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached

   */
  enum w1_master_flags {
  	W1_ABORT_SEARCH = 0,

  	W1_WARN_MAX_COUNT = 1,

  };

  /**
   * struct w1_master - one per bus master
   * @w1_master_entry:	master linked list
   * @owner:		module owner
   * @name:		dynamically allocate bus name
   * @list_mutex:		protect slist and async_list
   * @slist:		linked list of slaves
   * @async_list:		linked list of netlink commands to execute
   * @max_slave_count:	maximum number of slaves to search for at a time
   * @slave_count:	current number of slaves known
   * @attempts:		number of searches ran
   * @slave_ttl:		number of searches before a slave is timed out
   * @initialized:	prevent init/removal race conditions
   * @id:			w1 bus number
   * @search_count:	number of automatic searches to run, -1 unlimited
   * @search_id:		allows continuing a search
   * @refcnt:		reference count
   * @priv:		private data storage

   * @enable_pullup:	allows a strong pullup
   * @pullup_duration:	time for the next strong pullup
   * @flags:		one of w1_master_flags
   * @thread:		thread for bus search and netlink commands
   * @mutex:		protect most of w1_master
   * @bus_mutex:		pretect concurrent bus access
   * @driver:		sysfs driver
   * @dev:		sysfs device
   * @bus_master:		io operations available
   * @seq:		sequence number used for netlink broadcasts

   */

  struct w1_master {

  	struct list_head	w1_master_entry;
  	struct module		*owner;
  	unsigned char		name[W1_MAXNAMELEN];

  	/* list_mutex protects just slist and async_list so slaves can be
  	 * searched for and async commands added while the master has
  	 * w1_master.mutex locked and is operating on the bus.

  	 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex

  	 */
  	struct mutex		list_mutex;

  	struct list_head	slist;

  	struct list_head	async_list;

  	int			max_slave_count, slave_count;
  	unsigned long		attempts;
  	int			slave_ttl;
  	int			initialized;
  	u32			id;

  	int			search_count;

  	/* id to start searching on, to continue a search or 0 to restart */
  	u64			search_id;

  
  	atomic_t		refcnt;
  
  	void			*priv;

  	/** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
  	int			enable_pullup;
  	/** 5V strong pullup duration in milliseconds, zero disabled. */
  	int			pullup_duration;

  	long			flags;

  	struct task_struct	*thread;

  	struct mutex		mutex;

  	struct mutex		bus_mutex;

  
  	struct device_driver	*driver;

  	struct device		dev;

  
  	struct w1_bus_master	*bus_master;

  	u32			seq;

  };

  int w1_add_master_device(struct w1_bus_master *master);
  void w1_remove_master_device(struct w1_bus_master *master);

  /**

   * struct w1_family_ops - operations for a family type
   * @add_slave: add_slave
   * @remove_slave: remove_slave
   * @groups: sysfs group

   * @chip_info: pointer to struct hwmon_chip_info

   */

  struct w1_family_ops {
  	int  (*add_slave)(struct w1_slave *sl);
  	void (*remove_slave)(struct w1_slave *sl);
  	const struct attribute_group **groups;

  	const struct hwmon_chip_info *chip_info;

  };

  /**
   * struct w1_family - reference counted family structure.
   * @family_entry:	family linked list
   * @fid:		8 bit family identifier
   * @fops:		operations for this family
   * @refcnt:		reference counter
   */
  struct w1_family {
  	struct list_head	family_entry;
  	u8			fid;
  
  	struct w1_family_ops	*fops;
  
  	atomic_t		refcnt;
  };
  
  int w1_register_family(struct w1_family *family);
  void w1_unregister_family(struct w1_family *family);
  
  /**
   * module_w1_driver() - Helper macro for registering a 1-Wire families
   * @__w1_family: w1_family struct
   *
   * Helper macro for 1-Wire families which do not do anything special in module
   * init/exit. This eliminates a lot of boilerplate. Each module may only
   * use this macro once, and calling it replaces module_init() and module_exit()

   */

  #define module_w1_family(__w1_family) \
  	module_driver(__w1_family, w1_register_family, \
  			w1_unregister_family)

  u8 w1_triplet(struct w1_master *dev, int bdir);
  void w1_write_8(struct w1_master *, u8);

  u8 w1_read_8(struct w1_master *);

  int w1_reset_bus(struct w1_master *);
  u8 w1_calc_crc8(u8 *, int);
  void w1_write_block(struct w1_master *, const u8 *, int);

  void w1_touch_block(struct w1_master *, u8 *, int);

  u8 w1_read_block(struct w1_master *, u8 *, int);
  int w1_reset_select_slave(struct w1_slave *sl);

  int w1_reset_resume_command(struct w1_master *);

  void w1_next_pullup(struct w1_master *, int);

  static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
  {
  	return container_of(dev, struct w1_slave, dev);
  }
  
  static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
  {
  	return dev_to_w1_slave(container_of(kobj, struct device, kobj));
  }
  
  static inline struct w1_master* dev_to_w1_master(struct device *dev)
  {
  	return container_of(dev, struct w1_master, dev);
  }

  #endif /* __KERNEL__ */

  #endif /* __LINUX_W1_H */