Free Electrons

Embedded Linux Experts

 *	w1.h
 * Copyright (c) 2004 Evgeniy Polyakov <>
 * 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
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

#ifndef __W1_H
#define __W1_H

struct w1_reg_num
	__u64	family:8,
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u64	crc:8,
#error "Please fix <asm/byteorder.h>"

#ifdef __KERNEL__

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mutex.h>

#include "w1_family.h"

#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_READ_ROM		0x33
#define W1_READ_PSUPPLY		0xB4
#define W1_MATCH_ROM		0x55

#define W1_SLAVE_ACTIVE		0

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;
	u8			rom[9];
	u32			flags;
	int			ttl;

	struct w1_master	*master;
	struct w1_family	*family;
	void			*family_data;
	struct device		dev;
	struct completion	released;

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

 * 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
	/** the first parameter in all the functions below */
	void		*data;

	 * Sample the line level
	 * @return the level read (0 or 1)
	u8		(*read_bit)(void *);

	/** Sets the line level */
	void		(*write_bit)(void *, u8);

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

	 * Reads a bytes. Same as 8 touch_bit(1) calls.
	 * @return the byte read
	u8		(*read_byte)(void *);

	 * Writes a byte. Same as 8 touch_bit(x) calls.
	void		(*write_byte)(void *, u8);

	 * Same as a series of read_byte() calls
	 * @return the number of bytes read
	u8		(*read_block)(void *, u8 *, int);

	/** Same as a series of write_byte() calls */
	void		(*write_block)(void *, const u8 *, int);

	 * Combines two reads and a smart write for ROM searches
	 * @return bit0=Id bit1=comp_id bit2=dir_taken
	u8		(*triplet)(void *, u8);

	 * long write-0 with a read for the presence pulse detection
	 * @return -1=Error, 0=Device present, 1=No device present
	u8		(*reset_bus)(void *);

	 * Put out a strong pull-up pulse of the specified duration.
	 * @return -1=Error, 0=completed
	u8		(*set_pullup)(void *, int);

	/** Really nice hardware can handles the different types of ROM search
	 *  w1_master* is passed to the slave found callback.
	void		(*search)(void *, struct w1_master *,
		u8, w1_slave_found_callback);

struct w1_master
	struct list_head	w1_master_entry;
	struct module		*owner;
	unsigned char		name[W1_MAXNAMELEN];
	struct list_head	slist;
	int			max_slave_count, slave_count;
	unsigned long		attempts;
	int			slave_ttl;
	int			initialized;
	u32			id;
	int			search_count;

	atomic_t		refcnt;

	void			*priv;
	int			priv_size;

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

	struct task_struct	*thread;
	struct mutex		mutex;

	struct device_driver	*driver;
	struct device		dev;

	struct w1_bus_master	*bus_master;

	u32			seq;

int w1_create_master_attributes(struct w1_master *);
void w1_destroy_master_attributes(struct w1_master *master);
void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
struct w1_slave *w1_search_slave(struct w1_reg_num *id);
void w1_search_process(struct w1_master *dev, u8 search_type);
struct w1_master *w1_search_master_id(u32 id);

/* Disconnect and reconnect devices in the given family.  Used for finding
 * unclaimed devices after a family has been registered or releasing devices
 * after a family has been unregistered.  Set attach to 1 when a new family
 * has just been registered, to 0 when it has been unregistered.
void w1_reconnect_slaves(struct w1_family *f, int attach);
void w1_slave_detach(struct w1_slave *sl);

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);
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);

extern struct device_driver w1_master_driver;
extern struct device w1_master_device;
extern int w1_max_slave_count;
extern int w1_max_slave_ttl;
extern struct list_head w1_masters;
extern struct mutex w1_mlock;

extern int w1_process(void *);

#endif /* __KERNEL__ */

#endif /* __W1_H */