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* 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.
#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 {
__u64 family:8,
#elif defined(__BIG_ENDIAN_BITFIELD)
__u64 crc:8,
#error "Please fix <asm/byteorder.h>"
#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_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 {
* 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;
const struct of_device_id *of_match_table;
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, \
u8 w1_triplet(struct w1_master *dev, int bdir);
u8 w1_touch_bit(struct w1_master *dev, int bit);
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 */