1/* 2 * w1.h 3 * 4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> 5 * 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22#ifndef __W1_H 23#define __W1_H 24 25/** 26 * struct w1_reg_num - broken out slave device id 27 * 28 * @family: identifies the type of device 29 * @id: along with family is the unique device id 30 * @crc: checksum of the other bytes 31 */ 32struct w1_reg_num 33{ 34#if defined(__LITTLE_ENDIAN_BITFIELD) 35 __u64 family:8, 36 id:48, 37 crc:8; 38#elif defined(__BIG_ENDIAN_BITFIELD) 39 __u64 crc:8, 40 id:48, 41 family:8; 42#else 43#error "Please fix <asm/byteorder.h>" 44#endif 45}; 46 47#ifdef __KERNEL__ 48 49#include <linux/completion.h> 50#include <linux/device.h> 51#include <linux/mutex.h> 52 53#include "w1_family.h" 54 55#define W1_MAXNAMELEN 32 56 57#define W1_SEARCH 0xF0 58#define W1_ALARM_SEARCH 0xEC 59#define W1_CONVERT_TEMP 0x44 60#define W1_SKIP_ROM 0xCC 61#define W1_COPY_SCRATCHPAD 0x48 62#define W1_WRITE_SCRATCHPAD 0x4E 63#define W1_READ_SCRATCHPAD 0xBE 64#define W1_READ_ROM 0x33 65#define W1_READ_PSUPPLY 0xB4 66#define W1_MATCH_ROM 0x55 67#define W1_RESUME_CMD 0xA5 68 69#define W1_SLAVE_ACTIVE 0 70#define W1_SLAVE_DETACH 1 71 72/** 73 * struct w1_slave - holds a single slave device on the bus 74 * 75 * @owner: Points to the one wire "wire" kernel module. 76 * @name: Device id is ascii. 77 * @w1_slave_entry: data for the linked list 78 * @reg_num: the slave id in binary 79 * @refcnt: reference count, delete when 0 80 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH 81 * @ttl: decrement per search this slave isn't found, deatch at 0 82 * @master: bus which this slave is on 83 * @family: module for device family type 84 * @family_data: pointer for use by the family module 85 * @dev: kernel device identifier 86 * 87 */ 88struct w1_slave 89{ 90 struct module *owner; 91 unsigned char name[W1_MAXNAMELEN]; 92 struct list_head w1_slave_entry; 93 struct w1_reg_num reg_num; 94 atomic_t refcnt; 95 int ttl; 96 unsigned long flags; 97 98 struct w1_master *master; 99 struct w1_family *family; 100 void *family_data; 101 struct device dev; 102}; 103 104typedef void (*w1_slave_found_callback)(struct w1_master *, u64); 105 106 107/** 108 * struct w1_bus_master - operations available on a bus master 109 * 110 * @data: the first parameter in all the functions below 111 * 112 * @read_bit: Sample the line level @return the level read (0 or 1) 113 * 114 * @write_bit: Sets the line level 115 * 116 * @touch_bit: the lowest-level function for devices that really support the 117 * 1-wire protocol. 118 * touch_bit(0) = write-0 cycle 119 * touch_bit(1) = write-1 / read cycle 120 * @return the bit read (0 or 1) 121 * 122 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls. 123 * @return the byte read 124 * 125 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls. 126 * 127 * @read_block: Same as a series of read_byte() calls 128 * @return the number of bytes read 129 * 130 * @write_block: Same as a series of write_byte() calls 131 * 132 * @triplet: Combines two reads and a smart write for ROM searches 133 * @return bit0=Id bit1=comp_id bit2=dir_taken 134 * 135 * @reset_bus: long write-0 with a read for the presence pulse detection 136 * @return -1=Error, 0=Device present, 1=No device present 137 * 138 * @set_pullup: Put out a strong pull-up pulse of the specified duration. 139 * @return -1=Error, 0=completed 140 * 141 * @search: Really nice hardware can handles the different types of ROM search 142 * w1_master* is passed to the slave found callback. 143 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH 144 * 145 * Note: read_bit and write_bit are very low level functions and should only 146 * be used with hardware that doesn't really support 1-wire operations, 147 * like a parallel/serial port. 148 * Either define read_bit and write_bit OR define, at minimum, touch_bit and 149 * reset_bus. 150 * 151 */ 152struct w1_bus_master 153{ 154 void *data; 155 156 u8 (*read_bit)(void *); 157 158 void (*write_bit)(void *, u8); 159 160 u8 (*touch_bit)(void *, u8); 161 162 u8 (*read_byte)(void *); 163 164 void (*write_byte)(void *, u8); 165 166 u8 (*read_block)(void *, u8 *, int); 167 168 void (*write_block)(void *, const u8 *, int); 169 170 u8 (*triplet)(void *, u8); 171 172 u8 (*reset_bus)(void *); 173 174 u8 (*set_pullup)(void *, int); 175 176 void (*search)(void *, struct w1_master *, 177 u8, w1_slave_found_callback); 178}; 179 180/** 181 * enum w1_master_flags - bitfields used in w1_master.flags 182 * @W1_ABORT_SEARCH: abort searching early on shutdown 183 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached 184 */ 185enum w1_master_flags { 186 W1_ABORT_SEARCH = 0, 187 W1_WARN_MAX_COUNT = 1, 188}; 189 190/** 191 * struct w1_master - one per bus master 192 * @w1_master_entry: master linked list 193 * @owner: module owner 194 * @name: dynamically allocate bus name 195 * @list_mutex: protect slist and async_list 196 * @slist: linked list of slaves 197 * @async_list: linked list of netlink commands to execute 198 * @max_slave_count: maximum number of slaves to search for at a time 199 * @slave_count: current number of slaves known 200 * @attempts: number of searches ran 201 * @slave_ttl: number of searches before a slave is timed out 202 * @initialized: prevent init/removal race conditions 203 * @id: w1 bus number 204 * @search_count: number of automatic searches to run, -1 unlimited 205 * @search_id: allows continuing a search 206 * @refcnt: reference count 207 * @priv: private data storage 208 * @enable_pullup: allows a strong pullup 209 * @pullup_duration: time for the next strong pullup 210 * @flags: one of w1_master_flags 211 * @thread: thread for bus search and netlink commands 212 * @mutex: protect most of w1_master 213 * @bus_mutex: pretect concurrent bus access 214 * @driver: sysfs driver 215 * @dev: sysfs device 216 * @bus_master: io operations available 217 * @seq: sequence number used for netlink broadcasts 218 */ 219struct w1_master 220{ 221 struct list_head w1_master_entry; 222 struct module *owner; 223 unsigned char name[W1_MAXNAMELEN]; 224 /* list_mutex protects just slist and async_list so slaves can be 225 * searched for and async commands added while the master has 226 * w1_master.mutex locked and is operating on the bus. 227 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex 228 */ 229 struct mutex list_mutex; 230 struct list_head slist; 231 struct list_head async_list; 232 int max_slave_count, slave_count; 233 unsigned long attempts; 234 int slave_ttl; 235 int initialized; 236 u32 id; 237 int search_count; 238 /* id to start searching on, to continue a search or 0 to restart */ 239 u64 search_id; 240 241 atomic_t refcnt; 242 243 void *priv; 244 245 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ 246 int enable_pullup; 247 /** 5V strong pullup duration in milliseconds, zero disabled. */ 248 int pullup_duration; 249 250 long flags; 251 252 struct task_struct *thread; 253 struct mutex mutex; 254 struct mutex bus_mutex; 255 256 struct device_driver *driver; 257 struct device dev; 258 259 struct w1_bus_master *bus_master; 260 261 u32 seq; 262}; 263 264/** 265 * struct w1_async_cmd - execute callback from the w1_process kthread 266 * @async_entry: link entry 267 * @cb: callback function, must list_del and destroy this list before 268 * returning 269 * 270 * When inserted into the w1_master async_list, w1_process will execute 271 * the callback. Embed this into the structure with the command details. 272 */ 273struct w1_async_cmd { 274 struct list_head async_entry; 275 void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd); 276}; 277 278int w1_create_master_attributes(struct w1_master *); 279void w1_destroy_master_attributes(struct w1_master *master); 280void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); 281void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); 282/* call w1_unref_slave to release the reference counts w1_search_slave added */ 283struct w1_slave *w1_search_slave(struct w1_reg_num *id); 284/* decrements the reference on sl->master and sl, and cleans up if zero 285 * returns the reference count after it has been decremented */ 286int w1_unref_slave(struct w1_slave *sl); 287void w1_slave_found(struct w1_master *dev, u64 rn); 288void w1_search_process_cb(struct w1_master *dev, u8 search_type, 289 w1_slave_found_callback cb); 290struct w1_slave *w1_slave_search_device(struct w1_master *dev, 291 struct w1_reg_num *rn); 292struct w1_master *w1_search_master_id(u32 id); 293 294/* Disconnect and reconnect devices in the given family. Used for finding 295 * unclaimed devices after a family has been registered or releasing devices 296 * after a family has been unregistered. Set attach to 1 when a new family 297 * has just been registered, to 0 when it has been unregistered. 298 */ 299void w1_reconnect_slaves(struct w1_family *f, int attach); 300int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn); 301/* 0 success, otherwise EBUSY */ 302int w1_slave_detach(struct w1_slave *sl); 303 304u8 w1_triplet(struct w1_master *dev, int bdir); 305void w1_write_8(struct w1_master *, u8); 306u8 w1_read_8(struct w1_master *); 307int w1_reset_bus(struct w1_master *); 308u8 w1_calc_crc8(u8 *, int); 309void w1_write_block(struct w1_master *, const u8 *, int); 310void w1_touch_block(struct w1_master *, u8 *, int); 311u8 w1_read_block(struct w1_master *, u8 *, int); 312int w1_reset_select_slave(struct w1_slave *sl); 313int w1_reset_resume_command(struct w1_master *); 314void w1_next_pullup(struct w1_master *, int); 315 316static inline struct w1_slave* dev_to_w1_slave(struct device *dev) 317{ 318 return container_of(dev, struct w1_slave, dev); 319} 320 321static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj) 322{ 323 return dev_to_w1_slave(container_of(kobj, struct device, kobj)); 324} 325 326static inline struct w1_master* dev_to_w1_master(struct device *dev) 327{ 328 return container_of(dev, struct w1_master, dev); 329} 330 331extern struct device_driver w1_master_driver; 332extern struct device w1_master_device; 333extern int w1_max_slave_count; 334extern int w1_max_slave_ttl; 335extern struct list_head w1_masters; 336extern struct mutex w1_mlock; 337 338extern int w1_process_callbacks(struct w1_master *dev); 339extern int w1_process(void *); 340 341#endif /* __KERNEL__ */ 342 343#endif /* __W1_H */ 344