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 * Note: read_bit and write_bit are very low level functions and should only 122 * be used with hardware that doesn't really support 1-wire operations, 123 * like a parallel/serial port. 124 * Either define read_bit and write_bit OR define, at minimum, touch_bit and 125 * reset_bus. 126 * 127 */ 128struct w1_bus_master { 129 void *data; 130 131 u8 (*read_bit)(void *); 132 133 void (*write_bit)(void *, u8); 134 135 u8 (*touch_bit)(void *, u8); 136 137 u8 (*read_byte)(void *); 138 139 void (*write_byte)(void *, u8); 140 141 u8 (*read_block)(void *, u8 *, int); 142 143 void (*write_block)(void *, const u8 *, int); 144 145 u8 (*triplet)(void *, u8); 146 147 u8 (*reset_bus)(void *); 148 149 u8 (*set_pullup)(void *, int); 150 151 void (*search)(void *, struct w1_master *, 152 u8, w1_slave_found_callback); 153}; 154 155/** 156 * enum w1_master_flags - bitfields used in w1_master.flags 157 * @W1_ABORT_SEARCH: abort searching early on shutdown 158 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached 159 */ 160enum w1_master_flags { 161 W1_ABORT_SEARCH = 0, 162 W1_WARN_MAX_COUNT = 1, 163}; 164 165/** 166 * struct w1_master - one per bus master 167 * @w1_master_entry: master linked list 168 * @owner: module owner 169 * @name: dynamically allocate bus name 170 * @list_mutex: protect slist and async_list 171 * @slist: linked list of slaves 172 * @async_list: linked list of netlink commands to execute 173 * @max_slave_count: maximum number of slaves to search for at a time 174 * @slave_count: current number of slaves known 175 * @attempts: number of searches ran 176 * @slave_ttl: number of searches before a slave is timed out 177 * @initialized: prevent init/removal race conditions 178 * @id: w1 bus number 179 * @search_count: number of automatic searches to run, -1 unlimited 180 * @search_id: allows continuing a search 181 * @refcnt: reference count 182 * @priv: private data storage 183 * @enable_pullup: allows a strong pullup 184 * @pullup_duration: time for the next strong pullup 185 * @flags: one of w1_master_flags 186 * @thread: thread for bus search and netlink commands 187 * @mutex: protect most of w1_master 188 * @bus_mutex: pretect concurrent bus access 189 * @driver: sysfs driver 190 * @dev: sysfs device 191 * @bus_master: io operations available 192 * @seq: sequence number used for netlink broadcasts 193 */ 194struct w1_master { 195 struct list_head w1_master_entry; 196 struct module *owner; 197 unsigned char name[W1_MAXNAMELEN]; 198 /* list_mutex protects just slist and async_list so slaves can be 199 * searched for and async commands added while the master has 200 * w1_master.mutex locked and is operating on the bus. 201 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex 202 */ 203 struct mutex list_mutex; 204 struct list_head slist; 205 struct list_head async_list; 206 int max_slave_count, slave_count; 207 unsigned long attempts; 208 int slave_ttl; 209 int initialized; 210 u32 id; 211 int search_count; 212 /* id to start searching on, to continue a search or 0 to restart */ 213 u64 search_id; 214 215 atomic_t refcnt; 216 217 void *priv; 218 219 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ 220 int enable_pullup; 221 /** 5V strong pullup duration in milliseconds, zero disabled. */ 222 int pullup_duration; 223 224 long flags; 225 226 struct task_struct *thread; 227 struct mutex mutex; 228 struct mutex bus_mutex; 229 230 struct device_driver *driver; 231 struct device dev; 232 233 struct w1_bus_master *bus_master; 234 235 u32 seq; 236}; 237 238int w1_add_master_device(struct w1_bus_master *master); 239void w1_remove_master_device(struct w1_bus_master *master); 240 241/** 242 * struct w1_family_ops - operations for a family type 243 * @add_slave: add_slave 244 * @remove_slave: remove_slave 245 * @groups: sysfs group 246 * @chip_info: pointer to struct hwmon_chip_info 247 */ 248struct w1_family_ops { 249 int (*add_slave)(struct w1_slave *sl); 250 void (*remove_slave)(struct w1_slave *sl); 251 const struct attribute_group **groups; 252 const struct hwmon_chip_info *chip_info; 253}; 254 255/** 256 * struct w1_family - reference counted family structure. 257 * @family_entry: family linked list 258 * @fid: 8 bit family identifier 259 * @fops: operations for this family 260 * @refcnt: reference counter 261 */ 262struct w1_family { 263 struct list_head family_entry; 264 u8 fid; 265 266 struct w1_family_ops *fops; 267 268 const struct of_device_id *of_match_table; 269 270 atomic_t refcnt; 271}; 272 273int w1_register_family(struct w1_family *family); 274void w1_unregister_family(struct w1_family *family); 275 276/** 277 * module_w1_driver() - Helper macro for registering a 1-Wire families 278 * @__w1_family: w1_family struct 279 * 280 * Helper macro for 1-Wire families which do not do anything special in module 281 * init/exit. This eliminates a lot of boilerplate. Each module may only 282 * use this macro once, and calling it replaces module_init() and module_exit() 283 */ 284#define module_w1_family(__w1_family) \ 285 module_driver(__w1_family, w1_register_family, \ 286 w1_unregister_family) 287 288u8 w1_triplet(struct w1_master *dev, int bdir); 289u8 w1_touch_bit(struct w1_master *dev, int bit); 290void w1_write_8(struct w1_master *, u8); 291u8 w1_read_8(struct w1_master *); 292int w1_reset_bus(struct w1_master *); 293u8 w1_calc_crc8(u8 *, int); 294void w1_write_block(struct w1_master *, const u8 *, int); 295void w1_touch_block(struct w1_master *, u8 *, int); 296u8 w1_read_block(struct w1_master *, u8 *, int); 297int w1_reset_select_slave(struct w1_slave *sl); 298int w1_reset_resume_command(struct w1_master *); 299void w1_next_pullup(struct w1_master *, int); 300 301static inline struct w1_slave* dev_to_w1_slave(struct device *dev) 302{ 303 return container_of(dev, struct w1_slave, dev); 304} 305 306static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj) 307{ 308 return dev_to_w1_slave(container_of(kobj, struct device, kobj)); 309} 310 311static inline struct w1_master* dev_to_w1_master(struct device *dev) 312{ 313 return container_of(dev, struct w1_master, dev); 314} 315 316#endif /* __KERNEL__ */ 317 318#endif /* __LINUX_W1_H */ 319