drivers/w1/w1.h

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