1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
4 */
5
6 #ifndef __LINUX_W1_H
7 #define __LINUX_W1_H
8
9 #include <linux/device.h>
10
11 /**
12 * struct w1_reg_num - broken out slave device id
13 *
14 * @family: identifies the type of device
15 * @id: along with family is the unique device id
16 * @crc: checksum of the other bytes
17 */
18 struct w1_reg_num {
19 #if defined(__LITTLE_ENDIAN_BITFIELD)
20 __u64 family:8,
21 id:48,
22 crc:8;
23 #elif defined(__BIG_ENDIAN_BITFIELD)
24 __u64 crc:8,
25 id:48,
26 family:8;
27 #else
28 #error "Please fix <asm/byteorder.h>"
29 #endif
30 };
31
32 #ifdef __KERNEL__
33
34 #define W1_MAXNAMELEN 32
35
36 #define W1_SEARCH 0xF0
37 #define W1_ALARM_SEARCH 0xEC
38 #define W1_CONVERT_TEMP 0x44
39 #define W1_SKIP_ROM 0xCC
40 #define W1_COPY_SCRATCHPAD 0x48
41 #define W1_WRITE_SCRATCHPAD 0x4E
42 #define W1_READ_SCRATCHPAD 0xBE
43 #define W1_READ_ROM 0x33
44 #define W1_READ_PSUPPLY 0xB4
45 #define W1_MATCH_ROM 0x55
46 #define W1_RESUME_CMD 0xA5
47
48 /**
49 * struct w1_slave - holds a single slave device on the bus
50 *
51 * @owner: Points to the one wire "wire" kernel module.
52 * @name: Device id is ascii.
53 * @w1_slave_entry: data for the linked list
54 * @reg_num: the slave id in binary
55 * @refcnt: reference count, delete when 0
56 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
57 * @ttl: decrement per search this slave isn't found, deatch at 0
58 * @master: bus which this slave is on
59 * @family: module for device family type
60 * @family_data: pointer for use by the family module
61 * @dev: kernel device identifier
62 * @hwmon: pointer to hwmon device
63 *
64 */
65 struct w1_slave {
66 struct module *owner;
67 unsigned char name[W1_MAXNAMELEN];
68 struct list_head w1_slave_entry;
69 struct w1_reg_num reg_num;
70 atomic_t refcnt;
71 int ttl;
72 unsigned long flags;
73
74 struct w1_master *master;
75 struct w1_family *family;
76 void *family_data;
77 struct device dev;
78 struct device *hwmon;
79 };
80
81 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
82
83 /**
84 * struct w1_bus_master - operations available on a bus master
85 *
86 * @data: the first parameter in all the functions below
87 *
88 * @read_bit: Sample the line level @return the level read (0 or 1)
89 *
90 * @write_bit: Sets the line level
91 *
92 * @touch_bit: the lowest-level function for devices that really support the
93 * 1-wire protocol.
94 * touch_bit(0) = write-0 cycle
95 * touch_bit(1) = write-1 / read cycle
96 * @return the bit read (0 or 1)
97 *
98 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
99 * @return the byte read
100 *
101 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
102 *
103 * @read_block: Same as a series of read_byte() calls
104 * @return the number of bytes read
105 *
106 * @write_block: Same as a series of write_byte() calls
107 *
108 * @triplet: Combines two reads and a smart write for ROM searches
109 * @return bit0=Id bit1=comp_id bit2=dir_taken
110 *
111 * @reset_bus: long write-0 with a read for the presence pulse detection
112 * @return -1=Error, 0=Device present, 1=No device present
113 *
114 * @set_pullup: Put out a strong pull-up pulse of the specified duration.
115 * @return -1=Error, 0=completed
116 *
117 * @search: Really nice hardware can handles the different types of ROM search
118 * w1_master* is passed to the slave found callback.
119 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
120 *
121 * @dev_id: Optional device id string, which w1 slaves could use for
122 * creating names, which then give a connection to the w1 master
123 *
124 * Note: read_bit and write_bit are very low level functions and should only
125 * be used with hardware that doesn't really support 1-wire operations,
126 * like a parallel/serial port.
127 * Either define read_bit and write_bit OR define, at minimum, touch_bit and
128 * reset_bus.
129 *
130 */
131 struct w1_bus_master {
132 void *data;
133
134 u8 (*read_bit)(void *);
135
136 void (*write_bit)(void *, u8);
137
138 u8 (*touch_bit)(void *, u8);
139
140 u8 (*read_byte)(void *);
141
142 void (*write_byte)(void *, u8);
143
144 u8 (*read_block)(void *, u8 *, int);
145
146 void (*write_block)(void *, const u8 *, int);
147
148 u8 (*triplet)(void *, u8);
149
150 u8 (*reset_bus)(void *);
151
152 u8 (*set_pullup)(void *, int);
153
154 void (*search)(void *, struct w1_master *,
155 u8, w1_slave_found_callback);
156
157 char *dev_id;
158 };
159
160 /**
161 * enum w1_master_flags - bitfields used in w1_master.flags
162 * @W1_ABORT_SEARCH: abort searching early on shutdown
163 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
164 */
165 enum w1_master_flags {
166 W1_ABORT_SEARCH = 0,
167 W1_WARN_MAX_COUNT = 1,
168 };
169
170 /**
171 * struct w1_master - one per bus master
172 * @w1_master_entry: master linked list
173 * @owner: module owner
174 * @name: dynamically allocate bus name
175 * @list_mutex: protect slist and async_list
176 * @slist: linked list of slaves
177 * @async_list: linked list of netlink commands to execute
178 * @max_slave_count: maximum number of slaves to search for at a time
179 * @slave_count: current number of slaves known
180 * @attempts: number of searches ran
181 * @slave_ttl: number of searches before a slave is timed out
182 * @initialized: prevent init/removal race conditions
183 * @id: w1 bus number
184 * @search_count: number of automatic searches to run, -1 unlimited
185 * @search_id: allows continuing a search
186 * @refcnt: reference count
187 * @priv: private data storage
188 * @enable_pullup: allows a strong pullup
189 * @pullup_duration: time for the next strong pullup
190 * @flags: one of w1_master_flags
191 * @thread: thread for bus search and netlink commands
192 * @mutex: protect most of w1_master
193 * @bus_mutex: pretect concurrent bus access
194 * @driver: sysfs driver
195 * @dev: sysfs device
196 * @bus_master: io operations available
197 * @seq: sequence number used for netlink broadcasts
198 */
199 struct w1_master {
200 struct list_head w1_master_entry;
201 struct module *owner;
202 unsigned char name[W1_MAXNAMELEN];
203 /* list_mutex protects just slist and async_list so slaves can be
204 * searched for and async commands added while the master has
205 * w1_master.mutex locked and is operating on the bus.
206 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
207 */
208 struct mutex list_mutex;
209 struct list_head slist;
210 struct list_head async_list;
211 int max_slave_count, slave_count;
212 unsigned long attempts;
213 int slave_ttl;
214 int initialized;
215 u32 id;
216 int search_count;
217 /* id to start searching on, to continue a search or 0 to restart */
218 u64 search_id;
219
220 atomic_t refcnt;
221
222 void *priv;
223
224 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
225 int enable_pullup;
226 /** 5V strong pullup duration in milliseconds, zero disabled. */
227 int pullup_duration;
228
229 long flags;
230
231 struct task_struct *thread;
232 struct mutex mutex;
233 struct mutex bus_mutex;
234
235 struct device_driver *driver;
236 struct device dev;
237
238 struct w1_bus_master *bus_master;
239
240 u32 seq;
241 };
242
243 int w1_add_master_device(struct w1_bus_master *master);
244 void w1_remove_master_device(struct w1_bus_master *master);
245
246 /**
247 * struct w1_family_ops - operations for a family type
248 * @add_slave: add_slave
249 * @remove_slave: remove_slave
250 * @groups: sysfs group
251 * @chip_info: pointer to struct hwmon_chip_info
252 */
253 struct w1_family_ops {
254 int (*add_slave)(struct w1_slave *sl);
255 void (*remove_slave)(struct w1_slave *sl);
256 const struct attribute_group **groups;
257 const struct hwmon_chip_info *chip_info;
258 };
259
260 /**
261 * struct w1_family - reference counted family structure.
262 * @family_entry: family linked list
263 * @fid: 8 bit family identifier
264 * @fops: operations for this family
265 * @refcnt: reference counter
266 */
267 struct w1_family {
268 struct list_head family_entry;
269 u8 fid;
270
271 struct w1_family_ops *fops;
272
273 const struct of_device_id *of_match_table;
274
275 atomic_t refcnt;
276 };
277
278 int w1_register_family(struct w1_family *family);
279 void w1_unregister_family(struct w1_family *family);
280
281 /**
282 * module_w1_driver() - Helper macro for registering a 1-Wire families
283 * @__w1_family: w1_family struct
284 *
285 * Helper macro for 1-Wire families which do not do anything special in module
286 * init/exit. This eliminates a lot of boilerplate. Each module may only
287 * use this macro once, and calling it replaces module_init() and module_exit()
288 */
289 #define module_w1_family(__w1_family) \
290 module_driver(__w1_family, w1_register_family, \
291 w1_unregister_family)
292
293 u8 w1_triplet(struct w1_master *dev, int bdir);
294 u8 w1_touch_bit(struct w1_master *dev, int bit);
295 void w1_write_8(struct w1_master *, u8);
296 u8 w1_read_8(struct w1_master *);
297 int w1_reset_bus(struct w1_master *);
298 u8 w1_calc_crc8(u8 *, int);
299 void w1_write_block(struct w1_master *, const u8 *, int);
300 void w1_touch_block(struct w1_master *, u8 *, int);
301 u8 w1_read_block(struct w1_master *, u8 *, int);
302 int w1_reset_select_slave(struct w1_slave *sl);
303 int w1_reset_resume_command(struct w1_master *);
304 void w1_next_pullup(struct w1_master *, int);
305
306 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
307 {
308 return container_of(dev, struct w1_slave, dev);
309 }
310
311 static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
312 {
313 return dev_to_w1_slave(container_of(kobj, struct device, kobj));
314 }
315
316 static inline struct w1_master* dev_to_w1_master(struct device *dev)
317 {
318 return container_of(dev, struct w1_master, dev);
319 }
320
321 #endif /* __KERNEL__ */
322
323 #endif /* __LINUX_W1_H */