1 /* 2 * Copyright (c) 2004 Evgeniy Polyakov <[email protected]> 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 * 72 */ 73 struct w1_slave { 74 struct module *owner; 75 unsigned char name[W1_MAXNAMELEN]; 76 struct list_head w1_slave_entry; 77 struct w1_reg_num reg_num; 78 atomic_t refcnt; 79 int ttl; 80 unsigned long flags; 81 82 struct w1_master *master; 83 struct w1_family *family; 84 void *family_data; 85 struct device dev; 86 }; 87 88 typedef void (*w1_slave_found_callback)(struct w1_master *, u64); 89 90 /** 91 * struct w1_bus_master - operations available on a bus master 92 * 93 * @data: the first parameter in all the functions below 94 * 95 * @read_bit: Sample the line level @return the level read (0 or 1) 96 * 97 * @write_bit: Sets the line level 98 * 99 * @touch_bit: the lowest-level function for devices that really support the 100 * 1-wire protocol. 101 * touch_bit(0) = write-0 cycle 102 * touch_bit(1) = write-1 / read cycle 103 * @return the bit read (0 or 1) 104 * 105 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls. 106 * @return the byte read 107 * 108 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls. 109 * 110 * @read_block: Same as a series of read_byte() calls 111 * @return the number of bytes read 112 * 113 * @write_block: Same as a series of write_byte() calls 114 * 115 * @triplet: Combines two reads and a smart write for ROM searches 116 * @return bit0=Id bit1=comp_id bit2=dir_taken 117 * 118 * @reset_bus: long write-0 with a read for the presence pulse detection 119 * @return -1=Error, 0=Device present, 1=No device present 120 * 121 * @set_pullup: Put out a strong pull-up pulse of the specified duration. 122 * @return -1=Error, 0=completed 123 * 124 * @search: Really nice hardware can handles the different types of ROM search 125 * w1_master* is passed to the slave found callback. 126 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH 127 * 128 * Note: read_bit and write_bit are very low level functions and should only 129 * be used with hardware that doesn't really support 1-wire operations, 130 * like a parallel/serial port. 131 * Either define read_bit and write_bit OR define, at minimum, touch_bit and 132 * reset_bus. 133 * 134 */ 135 struct w1_bus_master { 136 void *data; 137 138 u8 (*read_bit)(void *); 139 140 void (*write_bit)(void *, u8); 141 142 u8 (*touch_bit)(void *, u8); 143 144 u8 (*read_byte)(void *); 145 146 void (*write_byte)(void *, u8); 147 148 u8 (*read_block)(void *, u8 *, int); 149 150 void (*write_block)(void *, const u8 *, int); 151 152 u8 (*triplet)(void *, u8); 153 154 u8 (*reset_bus)(void *); 155 156 u8 (*set_pullup)(void *, int); 157 158 void (*search)(void *, struct w1_master *, 159 u8, w1_slave_found_callback); 160 }; 161 162 /** 163 * enum w1_master_flags - bitfields used in w1_master.flags 164 * @W1_ABORT_SEARCH: abort searching early on shutdown 165 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached 166 */ 167 enum w1_master_flags { 168 W1_ABORT_SEARCH = 0, 169 W1_WARN_MAX_COUNT = 1, 170 }; 171 172 /** 173 * struct w1_master - one per bus master 174 * @w1_master_entry: master linked list 175 * @owner: module owner 176 * @name: dynamically allocate bus name 177 * @list_mutex: protect slist and async_list 178 * @slist: linked list of slaves 179 * @async_list: linked list of netlink commands to execute 180 * @max_slave_count: maximum number of slaves to search for at a time 181 * @slave_count: current number of slaves known 182 * @attempts: number of searches ran 183 * @slave_ttl: number of searches before a slave is timed out 184 * @initialized: prevent init/removal race conditions 185 * @id: w1 bus number 186 * @search_count: number of automatic searches to run, -1 unlimited 187 * @search_id: allows continuing a search 188 * @refcnt: reference count 189 * @priv: private data storage 190 * @enable_pullup: allows a strong pullup 191 * @pullup_duration: time for the next strong pullup 192 * @flags: one of w1_master_flags 193 * @thread: thread for bus search and netlink commands 194 * @mutex: protect most of w1_master 195 * @bus_mutex: pretect concurrent bus access 196 * @driver: sysfs driver 197 * @dev: sysfs device 198 * @bus_master: io operations available 199 * @seq: sequence number used for netlink broadcasts 200 */ 201 struct w1_master { 202 struct list_head w1_master_entry; 203 struct module *owner; 204 unsigned char name[W1_MAXNAMELEN]; 205 /* list_mutex protects just slist and async_list so slaves can be 206 * searched for and async commands added while the master has 207 * w1_master.mutex locked and is operating on the bus. 208 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex 209 */ 210 struct mutex list_mutex; 211 struct list_head slist; 212 struct list_head async_list; 213 int max_slave_count, slave_count; 214 unsigned long attempts; 215 int slave_ttl; 216 int initialized; 217 u32 id; 218 int search_count; 219 /* id to start searching on, to continue a search or 0 to restart */ 220 u64 search_id; 221 222 atomic_t refcnt; 223 224 void *priv; 225 226 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ 227 int enable_pullup; 228 /** 5V strong pullup duration in milliseconds, zero disabled. */ 229 int pullup_duration; 230 231 long flags; 232 233 struct task_struct *thread; 234 struct mutex mutex; 235 struct mutex bus_mutex; 236 237 struct device_driver *driver; 238 struct device dev; 239 240 struct w1_bus_master *bus_master; 241 242 u32 seq; 243 }; 244 245 int w1_add_master_device(struct w1_bus_master *master); 246 void w1_remove_master_device(struct w1_bus_master *master); 247 248 /** 249 * struct w1_family_ops - operations for a family type 250 * @add_slave: add_slave 251 * @remove_slave: remove_slave 252 * @groups: sysfs group 253 */ 254 struct w1_family_ops { 255 int (*add_slave)(struct w1_slave *sl); 256 void (*remove_slave)(struct w1_slave *sl); 257 const struct attribute_group **groups; 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 atomic_t refcnt; 274 }; 275 276 int w1_register_family(struct w1_family *family); 277 void w1_unregister_family(struct w1_family *family); 278 279 /** 280 * module_w1_driver() - Helper macro for registering a 1-Wire families 281 * @__w1_family: w1_family struct 282 * 283 * Helper macro for 1-Wire families which do not do anything special in module 284 * init/exit. This eliminates a lot of boilerplate. Each module may only 285 * use this macro once, and calling it replaces module_init() and module_exit() 286 */ 287 #define module_w1_family(__w1_family) \ 288 module_driver(__w1_family, w1_register_family, \ 289 w1_unregister_family) 290 291 u8 w1_triplet(struct w1_master *dev, int bdir); 292 void w1_write_8(struct w1_master *, u8); 293 u8 w1_read_8(struct w1_master *); 294 int w1_reset_bus(struct w1_master *); 295 u8 w1_calc_crc8(u8 *, int); 296 void w1_write_block(struct w1_master *, const u8 *, int); 297 void w1_touch_block(struct w1_master *, u8 *, int); 298 u8 w1_read_block(struct w1_master *, u8 *, int); 299 int w1_reset_select_slave(struct w1_slave *sl); 300 int w1_reset_resume_command(struct w1_master *); 301 void w1_next_pullup(struct w1_master *, int); 302 303 static inline struct w1_slave* dev_to_w1_slave(struct device *dev) 304 { 305 return container_of(dev, struct w1_slave, dev); 306 } 307 308 static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj) 309 { 310 return dev_to_w1_slave(container_of(kobj, struct device, kobj)); 311 } 312 313 static inline struct w1_master* dev_to_w1_master(struct device *dev) 314 { 315 return container_of(dev, struct w1_master, dev); 316 } 317 318 #endif /* __KERNEL__ */ 319 320 #endif /* __LINUX_W1_H */ 321