1 /*
2 * w1.h
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #ifndef __W1_H
23 #define __W1_H
24
25 /**
26 * struct w1_reg_num - broken out slave device id
27 *
28 * @family: identifies the type of device
29 * @id: along with family is the unique device id
30 * @crc: checksum of the other bytes
31 */
32 struct w1_reg_num
33 {
34 #if defined(__LITTLE_ENDIAN_BITFIELD)
35 __u64 family:8,
36 id:48,
37 crc:8;
38 #elif defined(__BIG_ENDIAN_BITFIELD)
39 __u64 crc:8,
40 id:48,
41 family:8;
42 #else
43 #error "Please fix <asm/byteorder.h>"
44 #endif
45 };
46
47 #ifdef __KERNEL__
48
49 #include <linux/completion.h>
50 #include <linux/device.h>
51 #include <linux/mutex.h>
52
53 #include "w1_family.h"
54
55 #define W1_MAXNAMELEN 32
56
57 #define W1_SEARCH 0xF0
58 #define W1_ALARM_SEARCH 0xEC
59 #define W1_CONVERT_TEMP 0x44
60 #define W1_SKIP_ROM 0xCC
61 #define W1_READ_SCRATCHPAD 0xBE
62 #define W1_READ_ROM 0x33
63 #define W1_READ_PSUPPLY 0xB4
64 #define W1_MATCH_ROM 0x55
65 #define W1_RESUME_CMD 0xA5
66
67 #define W1_SLAVE_ACTIVE 0
68 #define W1_SLAVE_DETACH 1
69
70 /**
71 * struct w1_slave - holds a single slave device on the bus
72 *
73 * @owner: Points to the one wire "wire" kernel module.
74 * @name: Device id is ascii.
75 * @w1_slave_entry: data for the linked list
76 * @reg_num: the slave id in binary
77 * @refcnt: reference count, delete when 0
78 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
79 * @ttl: decrement per search this slave isn't found, deatch at 0
80 * @master: bus which this slave is on
81 * @family: module for device family type
82 * @family_data: pointer for use by the family module
83 * @dev: kernel device identifier
84 *
85 */
86 struct w1_slave
87 {
88 struct module *owner;
89 unsigned char name[W1_MAXNAMELEN];
90 struct list_head w1_slave_entry;
91 struct w1_reg_num reg_num;
92 atomic_t refcnt;
93 int ttl;
94 unsigned long flags;
95
96 struct w1_master *master;
97 struct w1_family *family;
98 void *family_data;
99 struct device dev;
100 };
101
102 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
103
104
105 /**
106 * struct w1_bus_master - operations available on a bus master
107 *
108 * @data: the first parameter in all the functions below
109 *
110 * @read_bit: Sample the line level @return the level read (0 or 1)
111 *
112 * @write_bit: Sets the line level
113 *
114 * @touch_bit: the lowest-level function for devices that really support the
115 * 1-wire protocol.
116 * touch_bit(0) = write-0 cycle
117 * touch_bit(1) = write-1 / read cycle
118 * @return the bit read (0 or 1)
119 *
120 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
121 * @return the byte read
122 *
123 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
124 *
125 * @read_block: Same as a series of read_byte() calls
126 * @return the number of bytes read
127 *
128 * @write_block: Same as a series of write_byte() calls
129 *
130 * @triplet: Combines two reads and a smart write for ROM searches
131 * @return bit0=Id bit1=comp_id bit2=dir_taken
132 *
133 * @reset_bus: long write-0 with a read for the presence pulse detection
134 * @return -1=Error, 0=Device present, 1=No device present
135 *
136 * @set_pullup: Put out a strong pull-up pulse of the specified duration.
137 * @return -1=Error, 0=completed
138 *
139 * @search: Really nice hardware can handles the different types of ROM search
140 * w1_master* is passed to the slave found callback.
141 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
142 *
143 * Note: read_bit and write_bit are very low level functions and should only
144 * be used with hardware that doesn't really support 1-wire operations,
145 * like a parallel/serial port.
146 * Either define read_bit and write_bit OR define, at minimum, touch_bit and
147 * reset_bus.
148 *
149 */
150 struct w1_bus_master
151 {
152 void *data;
153
154 u8 (*read_bit)(void *);
155
156 void (*write_bit)(void *, u8);
157
158 u8 (*touch_bit)(void *, u8);
159
160 u8 (*read_byte)(void *);
161
162 void (*write_byte)(void *, u8);
163
164 u8 (*read_block)(void *, u8 *, int);
165
166 void (*write_block)(void *, const u8 *, int);
167
168 u8 (*triplet)(void *, u8);
169
170 u8 (*reset_bus)(void *);
171
172 u8 (*set_pullup)(void *, int);
173
174 void (*search)(void *, struct w1_master *,
175 u8, w1_slave_found_callback);
176 };
177
178 /**
179 * enum w1_master_flags - bitfields used in w1_master.flags
180 * @W1_ABORT_SEARCH: abort searching early on shutdown
181 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
182 */
183 enum w1_master_flags {
184 W1_ABORT_SEARCH = 0,
185 W1_WARN_MAX_COUNT = 1,
186 };
187
188 /**
189 * struct w1_master - one per bus master
190 * @w1_master_entry: master linked list
191 * @owner: module owner
192 * @name: dynamically allocate bus name
193 * @list_mutex: protect slist and async_list
194 * @slist: linked list of slaves
195 * @async_list: linked list of netlink commands to execute
196 * @max_slave_count: maximum number of slaves to search for at a time
197 * @slave_count: current number of slaves known
198 * @attempts: number of searches ran
199 * @slave_ttl: number of searches before a slave is timed out
200 * @initialized: prevent init/removal race conditions
201 * @id: w1 bus number
202 * @search_count: number of automatic searches to run, -1 unlimited
203 * @search_id: allows continuing a search
204 * @refcnt: reference count
205 * @priv: private data storage
206 * @enable_pullup: allows a strong pullup
207 * @pullup_duration: time for the next strong pullup
208 * @flags: one of w1_master_flags
209 * @thread: thread for bus search and netlink commands
210 * @mutex: protect most of w1_master
211 * @bus_mutex: pretect concurrent bus access
212 * @driver: sysfs driver
213 * @dev: sysfs device
214 * @bus_master: io operations available
215 * @seq: sequence number used for netlink broadcasts
216 */
217 struct w1_master
218 {
219 struct list_head w1_master_entry;
220 struct module *owner;
221 unsigned char name[W1_MAXNAMELEN];
222 /* list_mutex protects just slist and async_list so slaves can be
223 * searched for and async commands added while the master has
224 * w1_master.mutex locked and is operating on the bus.
225 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
226 */
227 struct mutex list_mutex;
228 struct list_head slist;
229 struct list_head async_list;
230 int max_slave_count, slave_count;
231 unsigned long attempts;
232 int slave_ttl;
233 int initialized;
234 u32 id;
235 int search_count;
236 /* id to start searching on, to continue a search or 0 to restart */
237 u64 search_id;
238
239 atomic_t refcnt;
240
241 void *priv;
242
243 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
244 int enable_pullup;
245 /** 5V strong pullup duration in milliseconds, zero disabled. */
246 int pullup_duration;
247
248 long flags;
249
250 struct task_struct *thread;
251 struct mutex mutex;
252 struct mutex bus_mutex;
253
254 struct device_driver *driver;
255 struct device dev;
256
257 struct w1_bus_master *bus_master;
258
259 u32 seq;
260 };
261
262 /**
263 * struct w1_async_cmd - execute callback from the w1_process kthread
264 * @async_entry: link entry
265 * @cb: callback function, must list_del and destroy this list before
266 * returning
267 *
268 * When inserted into the w1_master async_list, w1_process will execute
269 * the callback. Embed this into the structure with the command details.
270 */
271 struct w1_async_cmd {
272 struct list_head async_entry;
273 void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
274 };
275
276 int w1_create_master_attributes(struct w1_master *);
277 void w1_destroy_master_attributes(struct w1_master *master);
278 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
279 void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
280 /* call w1_unref_slave to release the reference counts w1_search_slave added */
281 struct w1_slave *w1_search_slave(struct w1_reg_num *id);
282 /* decrements the reference on sl->master and sl, and cleans up if zero
283 * returns the reference count after it has been decremented */
284 int w1_unref_slave(struct w1_slave *sl);
285 void w1_slave_found(struct w1_master *dev, u64 rn);
286 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
287 w1_slave_found_callback cb);
288 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
289 struct w1_reg_num *rn);
290 struct w1_master *w1_search_master_id(u32 id);
291
292 /* Disconnect and reconnect devices in the given family. Used for finding
293 * unclaimed devices after a family has been registered or releasing devices
294 * after a family has been unregistered. Set attach to 1 when a new family
295 * has just been registered, to 0 when it has been unregistered.
296 */
297 void w1_reconnect_slaves(struct w1_family *f, int attach);
298 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
299 /* 0 success, otherwise EBUSY */
300 int w1_slave_detach(struct w1_slave *sl);
301
302 u8 w1_triplet(struct w1_master *dev, int bdir);
303 void w1_write_8(struct w1_master *, u8);
304 u8 w1_read_8(struct w1_master *);
305 int w1_reset_bus(struct w1_master *);
306 u8 w1_calc_crc8(u8 *, int);
307 void w1_write_block(struct w1_master *, const u8 *, int);
308 void w1_touch_block(struct w1_master *, u8 *, int);
309 u8 w1_read_block(struct w1_master *, u8 *, int);
310 int w1_reset_select_slave(struct w1_slave *sl);
311 int w1_reset_resume_command(struct w1_master *);
312 void w1_next_pullup(struct w1_master *, int);
313
dev_to_w1_slave(struct device * dev)314 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
315 {
316 return container_of(dev, struct w1_slave, dev);
317 }
318
kobj_to_w1_slave(struct kobject * kobj)319 static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
320 {
321 return dev_to_w1_slave(container_of(kobj, struct device, kobj));
322 }
323
dev_to_w1_master(struct device * dev)324 static inline struct w1_master* dev_to_w1_master(struct device *dev)
325 {
326 return container_of(dev, struct w1_master, dev);
327 }
328
329 extern struct device_driver w1_master_driver;
330 extern struct device w1_master_device;
331 extern int w1_max_slave_count;
332 extern int w1_max_slave_ttl;
333 extern struct list_head w1_masters;
334 extern struct mutex w1_mlock;
335
336 extern int w1_process_callbacks(struct w1_master *dev);
337 extern int w1_process(void *);
338
339 #endif /* __KERNEL__ */
340
341 #endif /* __W1_H */
342