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_READ_SCRATCHPAD 0xBE 62#define W1_READ_ROM 0x33 63#define W1_READ_PSUPPLY 0xB4 64#define W1_MATCH_ROM 0x55 65#define W1_RESUME_CMD 0xA5 66 67#define W1_SLAVE_ACTIVE 0 68#define W1_SLAVE_DETACH 1 69 70/** 71 * struct w1_slave - holds a single slave device on the bus 72 * 73 * @owner: Points to the one wire "wire" kernel module. 74 * @name: Device id is ascii. 75 * @w1_slave_entry: data for the linked list 76 * @reg_num: the slave id in binary 77 * @refcnt: reference count, delete when 0 78 * @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH 79 * @ttl: decrement per search this slave isn't found, deatch at 0 80 * @master: bus which this slave is on 81 * @family: module for device family type 82 * @family_data: pointer for use by the family module 83 * @dev: kernel device identifier 84 * 85 */ 86struct w1_slave 87{ 88 struct module *owner; 89 unsigned char name[W1_MAXNAMELEN]; 90 struct list_head w1_slave_entry; 91 struct w1_reg_num reg_num; 92 atomic_t refcnt; 93 int ttl; 94 unsigned long flags; 95 96 struct w1_master *master; 97 struct w1_family *family; 98 void *family_data; 99 struct device dev; 100}; 101 102typedef void (*w1_slave_found_callback)(struct w1_master *, u64); 103 104 105/** 106 * struct w1_bus_master - operations available on a bus master 107 * 108 * @data: the first parameter in all the functions below 109 * 110 * @read_bit: Sample the line level @return the level read (0 or 1) 111 * 112 * @write_bit: Sets the line level 113 * 114 * @touch_bit: the lowest-level function for devices that really support the 115 * 1-wire protocol. 116 * touch_bit(0) = write-0 cycle 117 * touch_bit(1) = write-1 / read cycle 118 * @return the bit read (0 or 1) 119 * 120 * @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls. 121 * @return the byte read 122 * 123 * @write_byte: Writes a byte. Same as 8 touch_bit(x) calls. 124 * 125 * @read_block: Same as a series of read_byte() calls 126 * @return the number of bytes read 127 * 128 * @write_block: Same as a series of write_byte() calls 129 * 130 * @triplet: Combines two reads and a smart write for ROM searches 131 * @return bit0=Id bit1=comp_id bit2=dir_taken 132 * 133 * @reset_bus: long write-0 with a read for the presence pulse detection 134 * @return -1=Error, 0=Device present, 1=No device present 135 * 136 * @set_pullup: Put out a strong pull-up pulse of the specified duration. 137 * @return -1=Error, 0=completed 138 * 139 * @search: Really nice hardware can handles the different types of ROM search 140 * w1_master* is passed to the slave found callback. 141 * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH 142 * 143 * Note: read_bit and write_bit are very low level functions and should only 144 * be used with hardware that doesn't really support 1-wire operations, 145 * like a parallel/serial port. 146 * Either define read_bit and write_bit OR define, at minimum, touch_bit and 147 * reset_bus. 148 * 149 */ 150struct w1_bus_master 151{ 152 void *data; 153 154 u8 (*read_bit)(void *); 155 156 void (*write_bit)(void *, u8); 157 158 u8 (*touch_bit)(void *, u8); 159 160 u8 (*read_byte)(void *); 161 162 void (*write_byte)(void *, u8); 163 164 u8 (*read_block)(void *, u8 *, int); 165 166 void (*write_block)(void *, const u8 *, int); 167 168 u8 (*triplet)(void *, u8); 169 170 u8 (*reset_bus)(void *); 171 172 u8 (*set_pullup)(void *, int); 173 174 void (*search)(void *, struct w1_master *, 175 u8, w1_slave_found_callback); 176}; 177 178/** 179 * enum w1_master_flags - bitfields used in w1_master.flags 180 * @W1_ABORT_SEARCH: abort searching early on shutdown 181 * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached 182 */ 183enum w1_master_flags { 184 W1_ABORT_SEARCH = 0, 185 W1_WARN_MAX_COUNT = 1, 186}; 187 188/** 189 * struct w1_master - one per bus master 190 * @w1_master_entry: master linked list 191 * @owner: module owner 192 * @name: dynamically allocate bus name 193 * @list_mutex: protect slist and async_list 194 * @slist: linked list of slaves 195 * @async_list: linked list of netlink commands to execute 196 * @max_slave_count: maximum number of slaves to search for at a time 197 * @slave_count: current number of slaves known 198 * @attempts: number of searches ran 199 * @slave_ttl: number of searches before a slave is timed out 200 * @initialized: prevent init/removal race conditions 201 * @id: w1 bus number 202 * @search_count: number of automatic searches to run, -1 unlimited 203 * @search_id: allows continuing a search 204 * @refcnt: reference count 205 * @priv: private data storage 206 * @enable_pullup: allows a strong pullup 207 * @pullup_duration: time for the next strong pullup 208 * @flags: one of w1_master_flags 209 * @thread: thread for bus search and netlink commands 210 * @mutex: protect most of w1_master 211 * @bus_mutex: pretect concurrent bus access 212 * @driver: sysfs driver 213 * @dev: sysfs device 214 * @bus_master: io operations available 215 * @seq: sequence number used for netlink broadcasts 216 */ 217struct w1_master 218{ 219 struct list_head w1_master_entry; 220 struct module *owner; 221 unsigned char name[W1_MAXNAMELEN]; 222 /* list_mutex protects just slist and async_list so slaves can be 223 * searched for and async commands added while the master has 224 * w1_master.mutex locked and is operating on the bus. 225 * lock order w1_mlock, w1_master.mutex, w1_master.list_mutex 226 */ 227 struct mutex list_mutex; 228 struct list_head slist; 229 struct list_head async_list; 230 int max_slave_count, slave_count; 231 unsigned long attempts; 232 int slave_ttl; 233 int initialized; 234 u32 id; 235 int search_count; 236 /* id to start searching on, to continue a search or 0 to restart */ 237 u64 search_id; 238 239 atomic_t refcnt; 240 241 void *priv; 242 243 /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ 244 int enable_pullup; 245 /** 5V strong pullup duration in milliseconds, zero disabled. */ 246 int pullup_duration; 247 248 long flags; 249 250 struct task_struct *thread; 251 struct mutex mutex; 252 struct mutex bus_mutex; 253 254 struct device_driver *driver; 255 struct device dev; 256 257 struct w1_bus_master *bus_master; 258 259 u32 seq; 260}; 261 262/** 263 * struct w1_async_cmd - execute callback from the w1_process kthread 264 * @async_entry: link entry 265 * @cb: callback function, must list_del and destroy this list before 266 * returning 267 * 268 * When inserted into the w1_master async_list, w1_process will execute 269 * the callback. Embed this into the structure with the command details. 270 */ 271struct w1_async_cmd { 272 struct list_head async_entry; 273 void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd); 274}; 275 276int w1_create_master_attributes(struct w1_master *); 277void w1_destroy_master_attributes(struct w1_master *master); 278void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); 279void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); 280/* call w1_unref_slave to release the reference counts w1_search_slave added */ 281struct w1_slave *w1_search_slave(struct w1_reg_num *id); 282/* decrements the reference on sl->master and sl, and cleans up if zero 283 * returns the reference count after it has been decremented */ 284int w1_unref_slave(struct w1_slave *sl); 285void w1_slave_found(struct w1_master *dev, u64 rn); 286void w1_search_process_cb(struct w1_master *dev, u8 search_type, 287 w1_slave_found_callback cb); 288struct w1_slave *w1_slave_search_device(struct w1_master *dev, 289 struct w1_reg_num *rn); 290struct w1_master *w1_search_master_id(u32 id); 291 292/* Disconnect and reconnect devices in the given family. Used for finding 293 * unclaimed devices after a family has been registered or releasing devices 294 * after a family has been unregistered. Set attach to 1 when a new family 295 * has just been registered, to 0 when it has been unregistered. 296 */ 297void w1_reconnect_slaves(struct w1_family *f, int attach); 298int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn); 299/* 0 success, otherwise EBUSY */ 300int w1_slave_detach(struct w1_slave *sl); 301 302u8 w1_triplet(struct w1_master *dev, int bdir); 303void w1_write_8(struct w1_master *, u8); 304u8 w1_read_8(struct w1_master *); 305int w1_reset_bus(struct w1_master *); 306u8 w1_calc_crc8(u8 *, int); 307void w1_write_block(struct w1_master *, const u8 *, int); 308void w1_touch_block(struct w1_master *, u8 *, int); 309u8 w1_read_block(struct w1_master *, u8 *, int); 310int w1_reset_select_slave(struct w1_slave *sl); 311int w1_reset_resume_command(struct w1_master *); 312void w1_next_pullup(struct w1_master *, int); 313 314static inline struct w1_slave* dev_to_w1_slave(struct device *dev) 315{ 316 return container_of(dev, struct w1_slave, dev); 317} 318 319static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj) 320{ 321 return dev_to_w1_slave(container_of(kobj, struct device, kobj)); 322} 323 324static inline struct w1_master* dev_to_w1_master(struct device *dev) 325{ 326 return container_of(dev, struct w1_master, dev); 327} 328 329extern struct device_driver w1_master_driver; 330extern struct device w1_master_device; 331extern int w1_max_slave_count; 332extern int w1_max_slave_ttl; 333extern struct list_head w1_masters; 334extern struct mutex w1_mlock; 335 336extern int w1_process_callbacks(struct w1_master *dev); 337extern int w1_process(void *); 338 339#endif /* __KERNEL__ */ 340 341#endif /* __W1_H */ 342