2 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
19 * struct w1_reg_num - broken out slave device id
21 * @family: identifies the type of device
22 * @id: along with family is the unique device id
23 * @crc: checksum of the other bytes
27 #if defined(__LITTLE_ENDIAN_BITFIELD)
31 #elif defined(__BIG_ENDIAN_BITFIELD)
36 #error "Please fix <asm/byteorder.h>"
42 #include <linux/completion.h>
43 #include <linux/device.h>
44 #include <linux/mutex.h>
46 #include "w1_family.h"
48 #define W1_MAXNAMELEN 32
50 #define W1_SEARCH 0xF0
51 #define W1_ALARM_SEARCH 0xEC
52 #define W1_CONVERT_TEMP 0x44
53 #define W1_SKIP_ROM 0xCC
54 #define W1_COPY_SCRATCHPAD 0x48
55 #define W1_WRITE_SCRATCHPAD 0x4E
56 #define W1_READ_SCRATCHPAD 0xBE
57 #define W1_READ_ROM 0x33
58 #define W1_READ_PSUPPLY 0xB4
59 #define W1_MATCH_ROM 0x55
60 #define W1_RESUME_CMD 0xA5
62 #define W1_SLAVE_ACTIVE 0
63 #define W1_SLAVE_DETACH 1
66 * struct w1_slave - holds a single slave device on the bus
68 * @owner: Points to the one wire "wire" kernel module.
69 * @name: Device id is ascii.
70 * @w1_slave_entry: data for the linked list
71 * @reg_num: the slave id in binary
72 * @refcnt: reference count, delete when 0
73 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
74 * @ttl: decrement per search this slave isn't found, deatch at 0
75 * @master: bus which this slave is on
76 * @family: module for device family type
77 * @family_data: pointer for use by the family module
78 * @dev: kernel device identifier
84 unsigned char name
[W1_MAXNAMELEN
];
85 struct list_head w1_slave_entry
;
86 struct w1_reg_num reg_num
;
91 struct w1_master
*master
;
92 struct w1_family
*family
;
97 typedef void (*w1_slave_found_callback
)(struct w1_master
*, u64
);
101 * struct w1_bus_master - operations available on a bus master
103 * @data: the first parameter in all the functions below
105 * @read_bit: Sample the line level @return the level read (0 or 1)
107 * @write_bit: Sets the line level
109 * @touch_bit: the lowest-level function for devices that really support the
111 * touch_bit(0) = write-0 cycle
112 * touch_bit(1) = write-1 / read cycle
113 * @return the bit read (0 or 1)
115 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
116 * @return the byte read
118 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
120 * @read_block: Same as a series of read_byte() calls
121 * @return the number of bytes read
123 * @write_block: Same as a series of write_byte() calls
125 * @triplet: Combines two reads and a smart write for ROM searches
126 * @return bit0=Id bit1=comp_id bit2=dir_taken
128 * @reset_bus: long write-0 with a read for the presence pulse detection
129 * @return -1=Error, 0=Device present, 1=No device present
131 * @set_pullup: Put out a strong pull-up pulse of the specified duration.
132 * @return -1=Error, 0=completed
134 * @search: Really nice hardware can handles the different types of ROM search
135 * w1_master* is passed to the slave found callback.
136 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
138 * Note: read_bit and write_bit are very low level functions and should only
139 * be used with hardware that doesn't really support 1-wire operations,
140 * like a parallel/serial port.
141 * Either define read_bit and write_bit OR define, at minimum, touch_bit and
149 u8 (*read_bit
)(void *);
151 void (*write_bit
)(void *, u8
);
153 u8 (*touch_bit
)(void *, u8
);
155 u8 (*read_byte
)(void *);
157 void (*write_byte
)(void *, u8
);
159 u8 (*read_block
)(void *, u8
*, int);
161 void (*write_block
)(void *, const u8
*, int);
163 u8 (*triplet
)(void *, u8
);
165 u8 (*reset_bus
)(void *);
167 u8 (*set_pullup
)(void *, int);
169 void (*search
)(void *, struct w1_master
*,
170 u8
, w1_slave_found_callback
);
174 * enum w1_master_flags - bitfields used in w1_master.flags
175 * @W1_ABORT_SEARCH: abort searching early on shutdown
176 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
178 enum w1_master_flags
{
180 W1_WARN_MAX_COUNT
= 1,
184 * struct w1_master - one per bus master
185 * @w1_master_entry: master linked list
186 * @owner: module owner
187 * @name: dynamically allocate bus name
188 * @list_mutex: protect slist and async_list
189 * @slist: linked list of slaves
190 * @async_list: linked list of netlink commands to execute
191 * @max_slave_count: maximum number of slaves to search for at a time
192 * @slave_count: current number of slaves known
193 * @attempts: number of searches ran
194 * @slave_ttl: number of searches before a slave is timed out
195 * @initialized: prevent init/removal race conditions
197 * @search_count: number of automatic searches to run, -1 unlimited
198 * @search_id: allows continuing a search
199 * @refcnt: reference count
200 * @priv: private data storage
201 * @enable_pullup: allows a strong pullup
202 * @pullup_duration: time for the next strong pullup
203 * @flags: one of w1_master_flags
204 * @thread: thread for bus search and netlink commands
205 * @mutex: protect most of w1_master
206 * @bus_mutex: pretect concurrent bus access
207 * @driver: sysfs driver
209 * @bus_master: io operations available
210 * @seq: sequence number used for netlink broadcasts
214 struct list_head w1_master_entry
;
215 struct module
*owner
;
216 unsigned char name
[W1_MAXNAMELEN
];
217 /* list_mutex protects just slist and async_list so slaves can be
218 * searched for and async commands added while the master has
219 * w1_master.mutex locked and is operating on the bus.
220 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
222 struct mutex list_mutex
;
223 struct list_head slist
;
224 struct list_head async_list
;
225 int max_slave_count
, slave_count
;
226 unsigned long attempts
;
231 /* id to start searching on, to continue a search or 0 to restart */
238 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
240 /** 5V strong pullup duration in milliseconds, zero disabled. */
245 struct task_struct
*thread
;
247 struct mutex bus_mutex
;
249 struct device_driver
*driver
;
252 struct w1_bus_master
*bus_master
;
258 * struct w1_async_cmd - execute callback from the w1_process kthread
259 * @async_entry: link entry
260 * @cb: callback function, must list_del and destroy this list before
263 * When inserted into the w1_master async_list, w1_process will execute
264 * the callback. Embed this into the structure with the command details.
266 struct w1_async_cmd
{
267 struct list_head async_entry
;
268 void (*cb
)(struct w1_master
*dev
, struct w1_async_cmd
*async_cmd
);
271 int w1_create_master_attributes(struct w1_master
*);
272 void w1_destroy_master_attributes(struct w1_master
*master
);
273 void w1_search(struct w1_master
*dev
, u8 search_type
, w1_slave_found_callback cb
);
274 void w1_search_devices(struct w1_master
*dev
, u8 search_type
, w1_slave_found_callback cb
);
275 /* call w1_unref_slave to release the reference counts w1_search_slave added */
276 struct w1_slave
*w1_search_slave(struct w1_reg_num
*id
);
277 /* decrements the reference on sl->master and sl, and cleans up if zero
278 * returns the reference count after it has been decremented */
279 int w1_unref_slave(struct w1_slave
*sl
);
280 void w1_slave_found(struct w1_master
*dev
, u64 rn
);
281 void w1_search_process_cb(struct w1_master
*dev
, u8 search_type
,
282 w1_slave_found_callback cb
);
283 struct w1_slave
*w1_slave_search_device(struct w1_master
*dev
,
284 struct w1_reg_num
*rn
);
285 struct w1_master
*w1_search_master_id(u32 id
);
287 /* Disconnect and reconnect devices in the given family. Used for finding
288 * unclaimed devices after a family has been registered or releasing devices
289 * after a family has been unregistered. Set attach to 1 when a new family
290 * has just been registered, to 0 when it has been unregistered.
292 void w1_reconnect_slaves(struct w1_family
*f
, int attach
);
293 int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
);
294 /* 0 success, otherwise EBUSY */
295 int w1_slave_detach(struct w1_slave
*sl
);
297 u8
w1_triplet(struct w1_master
*dev
, int bdir
);
298 void w1_write_8(struct w1_master
*, u8
);
299 u8
w1_read_8(struct w1_master
*);
300 int w1_reset_bus(struct w1_master
*);
301 u8
w1_calc_crc8(u8
*, int);
302 void w1_write_block(struct w1_master
*, const u8
*, int);
303 void w1_touch_block(struct w1_master
*, u8
*, int);
304 u8
w1_read_block(struct w1_master
*, u8
*, int);
305 int w1_reset_select_slave(struct w1_slave
*sl
);
306 int w1_reset_resume_command(struct w1_master
*);
307 void w1_next_pullup(struct w1_master
*, int);
309 static inline struct w1_slave
* dev_to_w1_slave(struct device
*dev
)
311 return container_of(dev
, struct w1_slave
, dev
);
314 static inline struct w1_slave
* kobj_to_w1_slave(struct kobject
*kobj
)
316 return dev_to_w1_slave(container_of(kobj
, struct device
, kobj
));
319 static inline struct w1_master
* dev_to_w1_master(struct device
*dev
)
321 return container_of(dev
, struct w1_master
, dev
);
324 extern struct device_driver w1_master_driver
;
325 extern struct device w1_master_device
;
326 extern int w1_max_slave_count
;
327 extern int w1_max_slave_ttl
;
328 extern struct list_head w1_masters
;
329 extern struct mutex w1_mlock
;
331 extern int w1_process_callbacks(struct w1_master
*dev
);
332 extern int w1_process(void *);
334 #endif /* __KERNEL__ */