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 */
18struct 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 */
65struct 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
81typedef 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 */
131struct 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 */
165enum 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 */
199struct 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
243int w1_add_master_device(struct w1_bus_master *master);
244void 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 */
253struct 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 * @of_match_table: open firmware match table
266 * @refcnt:		reference counter
267 */
268struct w1_family {
269	struct list_head	family_entry;
270	u8			fid;
271
272	const struct w1_family_ops *fops;
273
274	const struct of_device_id *of_match_table;
275
276	atomic_t		refcnt;
277};
278
279int w1_register_family(struct w1_family *family);
280void w1_unregister_family(struct w1_family *family);
281
282/**
283 * module_w1_family() - Helper macro for registering a 1-Wire families
284 * @__w1_family: w1_family struct
285 *
286 * Helper macro for 1-Wire families which do not do anything special in module
287 * init/exit. This eliminates a lot of boilerplate. Each module may only
288 * use this macro once, and calling it replaces module_init() and module_exit()
289 */
290#define module_w1_family(__w1_family) \
291	module_driver(__w1_family, w1_register_family, \
292			w1_unregister_family)
293
294u8 w1_triplet(struct w1_master *dev, int bdir);
295u8 w1_touch_bit(struct w1_master *dev, int bit);
296void w1_write_8(struct w1_master *, u8);
297u8 w1_read_8(struct w1_master *);
298int w1_reset_bus(struct w1_master *);
299u8 w1_calc_crc8(u8 *, int);
300void w1_write_block(struct w1_master *, const u8 *, int);
301void w1_touch_block(struct w1_master *, u8 *, int);
302u8 w1_read_block(struct w1_master *, u8 *, int);
303int w1_reset_select_slave(struct w1_slave *sl);
304int w1_reset_resume_command(struct w1_master *);
305void w1_next_pullup(struct w1_master *, int);
306
307static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
308{
309	return container_of(dev, struct w1_slave, dev);
310}
311
312static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
313{
314	return dev_to_w1_slave(container_of(kobj, struct device, kobj));
315}
316
317static inline struct w1_master* dev_to_w1_master(struct device *dev)
318{
319	return container_of(dev, struct w1_master, dev);
320}
321
322#endif /* __KERNEL__ */
323
324#endif /* __LINUX_W1_H */
325