1 /*
2 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
3 *
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.
8 *
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.
13 */
14
15 #ifndef __LINUX_W1_H
16 #define __LINUX_W1_H
17
18 #include <linux/device.h>
19
20 /**
21 * struct w1_reg_num - broken out slave device id
22 *
23 * @family: identifies the type of device
24 * @id: along with family is the unique device id
25 * @crc: checksum of the other bytes
26 */
27 struct w1_reg_num {
28 #if defined(__LITTLE_ENDIAN_BITFIELD)
29 __u64 family:8,
30 id:48,
31 crc:8;
32 #elif defined(__BIG_ENDIAN_BITFIELD)
33 __u64 crc:8,
34 id:48,
35 family:8;
36 #else
37 #error "Please fix <asm/byteorder.h>"
38 #endif
39 };
40
41 #ifdef __KERNEL__
42
43 #define W1_MAXNAMELEN 32
44
45 #define W1_SEARCH 0xF0
46 #define W1_ALARM_SEARCH 0xEC
47 #define W1_CONVERT_TEMP 0x44
48 #define W1_SKIP_ROM 0xCC
49 #define W1_COPY_SCRATCHPAD 0x48
50 #define W1_WRITE_SCRATCHPAD 0x4E
51 #define W1_READ_SCRATCHPAD 0xBE
52 #define W1_READ_ROM 0x33
53 #define W1_READ_PSUPPLY 0xB4
54 #define W1_MATCH_ROM 0x55
55 #define W1_RESUME_CMD 0xA5
56
57 /**
58 * struct w1_slave - holds a single slave device on the bus
59 *
60 * @owner: Points to the one wire "wire" kernel module.
61 * @name: Device id is ascii.
62 * @w1_slave_entry: data for the linked list
63 * @reg_num: the slave id in binary
64 * @refcnt: reference count, delete when 0
65 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
66 * @ttl: decrement per search this slave isn't found, deatch at 0
67 * @master: bus which this slave is on
68 * @family: module for device family type
69 * @family_data: pointer for use by the family module
70 * @dev: kernel device identifier
71 * @hwmon: pointer to hwmon device
72 *
73 */
74 struct w1_slave {
75 struct module *owner;
76 unsigned char name[W1_MAXNAMELEN];
77 struct list_head w1_slave_entry;
78 struct w1_reg_num reg_num;
79 atomic_t refcnt;
80 int ttl;
81 unsigned long flags;
82
83 struct w1_master *master;
84 struct w1_family *family;
85 void *family_data;
86 struct device dev;
87 struct device *hwmon;
88 };
89
90 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
91
92 /**
93 * struct w1_bus_master - operations available on a bus master
94 *
95 * @data: the first parameter in all the functions below
96 *
97 * @read_bit: Sample the line level @return the level read (0 or 1)
98 *
99 * @write_bit: Sets the line level
100 *
101 * @touch_bit: the lowest-level function for devices that really support the
102 * 1-wire protocol.
103 * touch_bit(0) = write-0 cycle
104 * touch_bit(1) = write-1 / read cycle
105 * @return the bit read (0 or 1)
106 *
107 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
108 * @return the byte read
109 *
110 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
111 *
112 * @read_block: Same as a series of read_byte() calls
113 * @return the number of bytes read
114 *
115 * @write_block: Same as a series of write_byte() calls
116 *
117 * @triplet: Combines two reads and a smart write for ROM searches
118 * @return bit0=Id bit1=comp_id bit2=dir_taken
119 *
120 * @reset_bus: long write-0 with a read for the presence pulse detection
121 * @return -1=Error, 0=Device present, 1=No device present
122 *
123 * @set_pullup: Put out a strong pull-up pulse of the specified duration.
124 * @return -1=Error, 0=completed
125 *
126 * @search: Really nice hardware can handles the different types of ROM search
127 * w1_master* is passed to the slave found callback.
128 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
129 *
130 * Note: read_bit and write_bit are very low level functions and should only
131 * be used with hardware that doesn't really support 1-wire operations,
132 * like a parallel/serial port.
133 * Either define read_bit and write_bit OR define, at minimum, touch_bit and
134 * reset_bus.
135 *
136 */
137 struct w1_bus_master {
138 void *data;
139
140 u8 (*read_bit)(void *);
141
142 void (*write_bit)(void *, u8);
143
144 u8 (*touch_bit)(void *, u8);
145
146 u8 (*read_byte)(void *);
147
148 void (*write_byte)(void *, u8);
149
150 u8 (*read_block)(void *, u8 *, int);
151
152 void (*write_block)(void *, const u8 *, int);
153
154 u8 (*triplet)(void *, u8);
155
156 u8 (*reset_bus)(void *);
157
158 u8 (*set_pullup)(void *, int);
159
160 void (*search)(void *, struct w1_master *,
161 u8, w1_slave_found_callback);
162 };
163
164 /**
165 * enum w1_master_flags - bitfields used in w1_master.flags
166 * @W1_ABORT_SEARCH: abort searching early on shutdown
167 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
168 */
169 enum w1_master_flags {
170 W1_ABORT_SEARCH = 0,
171 W1_WARN_MAX_COUNT = 1,
172 };
173
174 /**
175 * struct w1_master - one per bus master
176 * @w1_master_entry: master linked list
177 * @owner: module owner
178 * @name: dynamically allocate bus name
179 * @list_mutex: protect slist and async_list
180 * @slist: linked list of slaves
181 * @async_list: linked list of netlink commands to execute
182 * @max_slave_count: maximum number of slaves to search for at a time
183 * @slave_count: current number of slaves known
184 * @attempts: number of searches ran
185 * @slave_ttl: number of searches before a slave is timed out
186 * @initialized: prevent init/removal race conditions
187 * @id: w1 bus number
188 * @search_count: number of automatic searches to run, -1 unlimited
189 * @search_id: allows continuing a search
190 * @refcnt: reference count
191 * @priv: private data storage
192 * @enable_pullup: allows a strong pullup
193 * @pullup_duration: time for the next strong pullup
194 * @flags: one of w1_master_flags
195 * @thread: thread for bus search and netlink commands
196 * @mutex: protect most of w1_master
197 * @bus_mutex: pretect concurrent bus access
198 * @driver: sysfs driver
199 * @dev: sysfs device
200 * @bus_master: io operations available
201 * @seq: sequence number used for netlink broadcasts
202 */
203 struct w1_master {
204 struct list_head w1_master_entry;
205 struct module *owner;
206 unsigned char name[W1_MAXNAMELEN];
207 /* list_mutex protects just slist and async_list so slaves can be
208 * searched for and async commands added while the master has
209 * w1_master.mutex locked and is operating on the bus.
210 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
211 */
212 struct mutex list_mutex;
213 struct list_head slist;
214 struct list_head async_list;
215 int max_slave_count, slave_count;
216 unsigned long attempts;
217 int slave_ttl;
218 int initialized;
219 u32 id;
220 int search_count;
221 /* id to start searching on, to continue a search or 0 to restart */
222 u64 search_id;
223
224 atomic_t refcnt;
225
226 void *priv;
227
228 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
229 int enable_pullup;
230 /** 5V strong pullup duration in milliseconds, zero disabled. */
231 int pullup_duration;
232
233 long flags;
234
235 struct task_struct *thread;
236 struct mutex mutex;
237 struct mutex bus_mutex;
238
239 struct device_driver *driver;
240 struct device dev;
241
242 struct w1_bus_master *bus_master;
243
244 u32 seq;
245 };
246
247 int w1_add_master_device(struct w1_bus_master *master);
248 void w1_remove_master_device(struct w1_bus_master *master);
249
250 /**
251 * struct w1_family_ops - operations for a family type
252 * @add_slave: add_slave
253 * @remove_slave: remove_slave
254 * @groups: sysfs group
255 * @chip_info: pointer to struct hwmon_chip_info
256 */
257 struct w1_family_ops {
258 int (*add_slave)(struct w1_slave *sl);
259 void (*remove_slave)(struct w1_slave *sl);
260 const struct attribute_group **groups;
261 const struct hwmon_chip_info *chip_info;
262 };
263
264 /**
265 * struct w1_family - reference counted family structure.
266 * @family_entry: family linked list
267 * @fid: 8 bit family identifier
268 * @fops: operations for this family
269 * @refcnt: reference counter
270 */
271 struct w1_family {
272 struct list_head family_entry;
273 u8 fid;
274
275 struct w1_family_ops *fops;
276
277 const struct of_device_id *of_match_table;
278
279 atomic_t refcnt;
280 };
281
282 int w1_register_family(struct w1_family *family);
283 void w1_unregister_family(struct w1_family *family);
284
285 /**
286 * module_w1_driver() - Helper macro for registering a 1-Wire families
287 * @__w1_family: w1_family struct
288 *
289 * Helper macro for 1-Wire families which do not do anything special in module
290 * init/exit. This eliminates a lot of boilerplate. Each module may only
291 * use this macro once, and calling it replaces module_init() and module_exit()
292 */
293 #define module_w1_family(__w1_family) \
294 module_driver(__w1_family, w1_register_family, \
295 w1_unregister_family)
296
297 u8 w1_triplet(struct w1_master *dev, int bdir);
298 u8 w1_touch_bit(struct w1_master *dev, int bit);
299 void w1_write_8(struct w1_master *, u8);
300 u8 w1_read_8(struct w1_master *);
301 int w1_reset_bus(struct w1_master *);
302 u8 w1_calc_crc8(u8 *, int);
303 void w1_write_block(struct w1_master *, const u8 *, int);
304 void w1_touch_block(struct w1_master *, u8 *, int);
305 u8 w1_read_block(struct w1_master *, u8 *, int);
306 int w1_reset_select_slave(struct w1_slave *sl);
307 int w1_reset_resume_command(struct w1_master *);
308 void w1_next_pullup(struct w1_master *, int);
309
dev_to_w1_slave(struct device * dev)310 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
311 {
312 return container_of(dev, struct w1_slave, dev);
313 }
314
kobj_to_w1_slave(struct kobject * kobj)315 static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
316 {
317 return dev_to_w1_slave(container_of(kobj, struct device, kobj));
318 }
319
dev_to_w1_master(struct device * dev)320 static inline struct w1_master* dev_to_w1_master(struct device *dev)
321 {
322 return container_of(dev, struct w1_master, dev);
323 }
324
325 #endif /* __KERNEL__ */
326
327 #endif /* __LINUX_W1_H */
328