drivers/w1/w1.h

   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  */
  32 struct 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  */
  88 struct 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
 104 typedef 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  */
 152 struct 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  */
 185 enum 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  */
 219 struct 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  */
 273 struct w1_async_cmd {
 274         struct list_head        async_entry;
 275         void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
 276 };
 277
 278 int w1_create_master_attributes(struct w1_master *);
 279 void w1_destroy_master_attributes(struct w1_master *master);
 280 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
 281 void 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 */
 283 struct 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 */
 286 int w1_unref_slave(struct w1_slave *sl);
 287 void w1_slave_found(struct w1_master *dev, u64 rn);
 288 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
 289         w1_slave_found_callback cb);
 290 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
 291         struct w1_reg_num *rn);
 292 struct 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  */
 299 void w1_reconnect_slaves(struct w1_family *f, int attach);
 300 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
 301 /* 0 success, otherwise EBUSY */
 302 int w1_slave_detach(struct w1_slave *sl);
 303
 304 u8 w1_triplet(struct w1_master *dev, int bdir);
 305 void w1_write_8(struct w1_master *, u8);
 306 u8 w1_read_8(struct w1_master *);
 307 int w1_reset_bus(struct w1_master *);
 308 u8 w1_calc_crc8(u8 *, int);
 309 void w1_write_block(struct w1_master *, const u8 *, int);
 310 void w1_touch_block(struct w1_master *, u8 *, int);
 311 u8 w1_read_block(struct w1_master *, u8 *, int);
 312 int w1_reset_select_slave(struct w1_slave *sl);
 313 int w1_reset_resume_command(struct w1_master *);
 314 void w1_next_pullup(struct w1_master *, int);
 315
 316 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
 317 {
 318         return container_of(dev, struct w1_slave, dev);
 319 }
 320
 321 static 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
 326 static inline struct w1_master* dev_to_w1_master(struct device *dev)
 327 {
 328         return container_of(dev, struct w1_master, dev);
 329 }
 330
 331 extern struct device_driver w1_master_driver;
 332 extern struct device w1_master_device;
 333 extern int w1_max_slave_count;
 334 extern int w1_max_slave_ttl;
 335 extern struct list_head w1_masters;
 336 extern struct mutex w1_mlock;
 337
 338 extern int w1_process_callbacks(struct w1_master *dev);
 339 extern int w1_process(void *);
 340
 341 #endif /* __KERNEL__ */
 342
 343 #endif /* __W1_H */