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_COPY_SCRATCHPAD 0x48
62 #define W1_WRITE_SCRATCHPAD 0x4E
63 #define W1_READ_SCRATCHPAD 0xBE
64 #define W1_READ_ROM 0x33
65 #define W1_READ_PSUPPLY 0xB4
66 #define W1_MATCH_ROM 0x55
67 #define W1_RESUME_CMD 0xA5
68
69 #define W1_SLAVE_ACTIVE 0
70 #define W1_SLAVE_DETACH 1
71
72 /**
73 * struct w1_slave - holds a single slave device on the bus
74 *
75 * @owner: Points to the one wire "wire" kernel module.
76 * @name: Device id is ascii.
77 * @w1_slave_entry: data for the linked list
78 * @reg_num: the slave id in binary
79 * @refcnt: reference count, delete when 0
80 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
81 * @ttl: decrement per search this slave isn't found, deatch at 0
82 * @master: bus which this slave is on
83 * @family: module for device family type
84 * @family_data: pointer for use by the family module
85 * @dev: kernel device identifier
86 *
87 */
88 struct w1_slave
89 {
90 struct module *owner;
91 unsigned char name[W1_MAXNAMELEN];
92 struct list_head w1_slave_entry;
93 struct w1_reg_num reg_num;
94 atomic_t refcnt;
95 int ttl;
96 unsigned long flags;
97
98 struct w1_master *master;
99 struct w1_family *family;
100 void *family_data;
101 struct device dev;
102 };
103
104 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
105
106
107 /**
108 * struct w1_bus_master - operations available on a bus master
109 *
110 * @data: the first parameter in all the functions below
111 *
112 * @read_bit: Sample the line level @return the level read (0 or 1)
113 *
114 * @write_bit: Sets the line level
115 *
116 * @touch_bit: the lowest-level function for devices that really support the
117 * 1-wire protocol.
118 * touch_bit(0) = write-0 cycle
119 * touch_bit(1) = write-1 / read cycle
120 * @return the bit read (0 or 1)
121 *
122 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
123 * @return the byte read
124 *
125 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
126 *
127 * @read_block: Same as a series of read_byte() calls
128 * @return the number of bytes read
129 *
130 * @write_block: Same as a series of write_byte() calls
131 *
132 * @triplet: Combines two reads and a smart write for ROM searches
133 * @return bit0=Id bit1=comp_id bit2=dir_taken
134 *
135 * @reset_bus: long write-0 with a read for the presence pulse detection
136 * @return -1=Error, 0=Device present, 1=No device present
137 *
138 * @set_pullup: Put out a strong pull-up pulse of the specified duration.
139 * @return -1=Error, 0=completed
140 *
141 * @search: Really nice hardware can handles the different types of ROM search
142 * w1_master* is passed to the slave found callback.
143 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
144 *
145 * Note: read_bit and write_bit are very low level functions and should only
146 * be used with hardware that doesn't really support 1-wire operations,
147 * like a parallel/serial port.
148 * Either define read_bit and write_bit OR define, at minimum, touch_bit and
149 * reset_bus.
150 *
151 */
152 struct w1_bus_master
153 {
154 void *data;
155
156 u8 (*read_bit)(void *);
157
158 void (*write_bit)(void *, u8);
159
160 u8 (*touch_bit)(void *, u8);
161
162 u8 (*read_byte)(void *);
163
164 void (*write_byte)(void *, u8);
165
166 u8 (*read_block)(void *, u8 *, int);
167
168 void (*write_block)(void *, const u8 *, int);
169
170 u8 (*triplet)(void *, u8);
171
172 u8 (*reset_bus)(void *);
173
174 u8 (*set_pullup)(void *, int);
175
176 void (*search)(void *, struct w1_master *,
177 u8, w1_slave_found_callback);
178 };
179
180 /**
181 * enum w1_master_flags - bitfields used in w1_master.flags
182 * @W1_ABORT_SEARCH: abort searching early on shutdown
183 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
184 */
185 enum w1_master_flags {
186 W1_ABORT_SEARCH = 0,
187 W1_WARN_MAX_COUNT = 1,
188 };
189
190 /**
191 * struct w1_master - one per bus master
192 * @w1_master_entry: master linked list
193 * @owner: module owner
194 * @name: dynamically allocate bus name
195 * @list_mutex: protect slist and async_list
196 * @slist: linked list of slaves
197 * @async_list: linked list of netlink commands to execute
198 * @max_slave_count: maximum number of slaves to search for at a time
199 * @slave_count: current number of slaves known
200 * @attempts: number of searches ran
201 * @slave_ttl: number of searches before a slave is timed out
202 * @initialized: prevent init/removal race conditions
203 * @id: w1 bus number
204 * @search_count: number of automatic searches to run, -1 unlimited
205 * @search_id: allows continuing a search
206 * @refcnt: reference count
207 * @priv: private data storage
208 * @enable_pullup: allows a strong pullup
209 * @pullup_duration: time for the next strong pullup
210 * @flags: one of w1_master_flags
211 * @thread: thread for bus search and netlink commands
212 * @mutex: protect most of w1_master
213 * @bus_mutex: pretect concurrent bus access
214 * @driver: sysfs driver
215 * @dev: sysfs device
216 * @bus_master: io operations available
217 * @seq: sequence number used for netlink broadcasts
218 */
219 struct w1_master
220 {
221 struct list_head w1_master_entry;
222 struct module *owner;
223 unsigned char name[W1_MAXNAMELEN];
224 /* list_mutex protects just slist and async_list so slaves can be
225 * searched for and async commands added while the master has
226 * w1_master.mutex locked and is operating on the bus.
227 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
228 */
229 struct mutex list_mutex;
230 struct list_head slist;
231 struct list_head async_list;
232 int max_slave_count, slave_count;
233 unsigned long attempts;
234 int slave_ttl;
235 int initialized;
236 u32 id;
237 int search_count;
238 /* id to start searching on, to continue a search or 0 to restart */
239 u64 search_id;
240
241 atomic_t refcnt;
242
243 void *priv;
244
245 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
246 int enable_pullup;
247 /** 5V strong pullup duration in milliseconds, zero disabled. */
248 int pullup_duration;
249
250 long flags;
251
252 struct task_struct *thread;
253 struct mutex mutex;
254 struct mutex bus_mutex;
255
256 struct device_driver *driver;
257 struct device dev;
258
259 struct w1_bus_master *bus_master;
260
261 u32 seq;
262 };
263
264 /**
265 * struct w1_async_cmd - execute callback from the w1_process kthread
266 * @async_entry: link entry
267 * @cb: callback function, must list_del and destroy this list before
268 * returning
269 *
270 * When inserted into the w1_master async_list, w1_process will execute
271 * the callback. Embed this into the structure with the command details.
272 */
273 struct w1_async_cmd {
274 struct list_head async_entry;
275 void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
276 };
277
278 int w1_create_master_attributes(struct w1_master *);
279 void w1_destroy_master_attributes(struct w1_master *master);
280 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
281 void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
282 /* call w1_unref_slave to release the reference counts w1_search_slave added */
283 struct w1_slave *w1_search_slave(struct w1_reg_num *id);
284 /* decrements the reference on sl->master and sl, and cleans up if zero
285 * returns the reference count after it has been decremented */
286 int w1_unref_slave(struct w1_slave *sl);
287 void w1_slave_found(struct w1_master *dev, u64 rn);
288 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
289 w1_slave_found_callback cb);
290 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
291 struct w1_reg_num *rn);
292 struct w1_master *w1_search_master_id(u32 id);
293
294 /* Disconnect and reconnect devices in the given family. Used for finding
295 * unclaimed devices after a family has been registered or releasing devices
296 * after a family has been unregistered. Set attach to 1 when a new family
297 * has just been registered, to 0 when it has been unregistered.
298 */
299 void w1_reconnect_slaves(struct w1_family *f, int attach);
300 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
301 /* 0 success, otherwise EBUSY */
302 int w1_slave_detach(struct w1_slave *sl);
303
304 u8 w1_triplet(struct w1_master *dev, int bdir);
305 void w1_write_8(struct w1_master *, u8);
306 u8 w1_read_8(struct w1_master *);
307 int w1_reset_bus(struct w1_master *);
308 u8 w1_calc_crc8(u8 *, int);
309 void w1_write_block(struct w1_master *, const u8 *, int);
310 void w1_touch_block(struct w1_master *, u8 *, int);
311 u8 w1_read_block(struct w1_master *, u8 *, int);
312 int w1_reset_select_slave(struct w1_slave *sl);
313 int w1_reset_resume_command(struct w1_master *);
314 void w1_next_pullup(struct w1_master *, int);
315
dev_to_w1_slave(struct device * dev)316 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
317 {
318 return container_of(dev, struct w1_slave, dev);
319 }
320
kobj_to_w1_slave(struct kobject * kobj)321 static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
322 {
323 return dev_to_w1_slave(container_of(kobj, struct device, kobj));
324 }
325
dev_to_w1_master(struct device * dev)326 static inline struct w1_master* dev_to_w1_master(struct device *dev)
327 {
328 return container_of(dev, struct w1_master, dev);
329 }
330
331 extern struct device_driver w1_master_driver;
332 extern struct device w1_master_device;
333 extern int w1_max_slave_count;
334 extern int w1_max_slave_ttl;
335 extern struct list_head w1_masters;
336 extern struct mutex w1_mlock;
337
338 extern int w1_process_callbacks(struct w1_master *dev);
339 extern int w1_process(void *);
340
341 #endif /* __KERNEL__ */
342
343 #endif /* __W1_H */
344