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_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  */
  86 struct 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
 102 typedef 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  */
 150 struct 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  */
 183 enum 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  */
 217 struct 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  */
 271 struct w1_async_cmd {
 272         struct list_head        async_entry;
 273         void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
 274 };
 275
 276 int w1_create_master_attributes(struct w1_master *);
 277 void w1_destroy_master_attributes(struct w1_master *master);
 278 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
 279 void 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 */
 281 struct 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 */
 284 int w1_unref_slave(struct w1_slave *sl);
 285 void w1_slave_found(struct w1_master *dev, u64 rn);
 286 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
 287         w1_slave_found_callback cb);
 288 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
 289         struct w1_reg_num *rn);
 290 struct 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  */
 297 void w1_reconnect_slaves(struct w1_family *f, int attach);
 298 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
 299 /* 0 success, otherwise EBUSY */
 300 int w1_slave_detach(struct w1_slave *sl);
 301
 302 u8 w1_triplet(struct w1_master *dev, int bdir);
 303 void w1_write_8(struct w1_master *, u8);
 304 u8 w1_read_8(struct w1_master *);
 305 int w1_reset_bus(struct w1_master *);
 306 u8 w1_calc_crc8(u8 *, int);
 307 void w1_write_block(struct w1_master *, const u8 *, int);
 308 void w1_touch_block(struct w1_master *, u8 *, int);
 309 u8 w1_read_block(struct w1_master *, u8 *, int);
 310 int w1_reset_select_slave(struct w1_slave *sl);
 311 int w1_reset_resume_command(struct w1_master *);
 312 void w1_next_pullup(struct w1_master *, int);
 313
 314 static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
 315 {
 316         return container_of(dev, struct w1_slave, dev);
 317 }
 318
 319 static 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
 324 static inline struct w1_master* dev_to_w1_master(struct device *dev)
 325 {
 326         return container_of(dev, struct w1_master, dev);
 327 }
 328
 329 extern struct device_driver w1_master_driver;
 330 extern struct device w1_master_device;
 331 extern int w1_max_slave_count;
 332 extern int w1_max_slave_ttl;
 333 extern struct list_head w1_masters;
 334 extern struct mutex w1_mlock;
 335
 336 extern int w1_process_callbacks(struct w1_master *dev);
 337 extern int w1_process(void *);
 338
 339 #endif /* __KERNEL__ */
 340
 341 #endif /* __W1_H */