raid5: allow arbitrary max_hw_sectors
[deliverable/linux.git] / include / linux / i2c.h
1 /* ------------------------------------------------------------------------- */
2 /* */
3 /* i2c.h - definitions for the i2c-bus interface */
4 /* */
5 /* ------------------------------------------------------------------------- */
6 /* Copyright (C) 1995-2000 Simon G. Vogl
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 MA 02110-1301 USA. */
22 /* ------------------------------------------------------------------------- */
23
24 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
25 Frodo Looijaard <frodol@dds.nl> */
26 #ifndef _LINUX_I2C_H
27 #define _LINUX_I2C_H
28
29 #include <linux/mod_devicetable.h>
30 #include <linux/device.h> /* for struct device */
31 #include <linux/sched.h> /* for completion */
32 #include <linux/mutex.h>
33 #include <linux/of.h> /* for struct device_node */
34 #include <linux/swab.h> /* for swab16 */
35 #include <uapi/linux/i2c.h>
36
37 extern struct bus_type i2c_bus_type;
38 extern struct device_type i2c_adapter_type;
39
40 /* --- General options ------------------------------------------------ */
41
42 struct i2c_msg;
43 struct i2c_algorithm;
44 struct i2c_adapter;
45 struct i2c_client;
46 struct i2c_driver;
47 union i2c_smbus_data;
48 struct i2c_board_info;
49 enum i2c_slave_event;
50 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *);
51
52 struct module;
53
54 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
55 /*
56 * The master routines are the ones normally used to transmit data to devices
57 * on a bus (or read from them). Apart from two basic transfer functions to
58 * transmit one message at a time, a more complex version can be used to
59 * transmit an arbitrary number of messages without interruption.
60 * @count must be be less than 64k since msg.len is u16.
61 */
62 extern int i2c_master_send(const struct i2c_client *client, const char *buf,
63 int count);
64 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
65 int count);
66
67 /* Transfer num messages.
68 */
69 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
70 int num);
71 /* Unlocked flavor */
72 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
73 int num);
74
75 /* This is the very generalized SMBus access routine. You probably do not
76 want to use this, though; one of the functions below may be much easier,
77 and probably just as fast.
78 Note that we use i2c_adapter here, because you do not need a specific
79 smbus adapter to call this function. */
80 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
81 unsigned short flags, char read_write, u8 command,
82 int size, union i2c_smbus_data *data);
83
84 /* Now follow the 'nice' access routines. These also document the calling
85 conventions of i2c_smbus_xfer. */
86
87 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
88 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
89 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
90 u8 command);
91 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
92 u8 command, u8 value);
93 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
94 u8 command);
95 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
96 u8 command, u16 value);
97
98 static inline s32
99 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
100 {
101 s32 value = i2c_smbus_read_word_data(client, command);
102
103 return (value < 0) ? value : swab16(value);
104 }
105
106 static inline s32
107 i2c_smbus_write_word_swapped(const struct i2c_client *client,
108 u8 command, u16 value)
109 {
110 return i2c_smbus_write_word_data(client, command, swab16(value));
111 }
112
113 /* Returns the number of read bytes */
114 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
115 u8 command, u8 *values);
116 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
117 u8 command, u8 length, const u8 *values);
118 /* Returns the number of read bytes */
119 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
120 u8 command, u8 length, u8 *values);
121 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
122 u8 command, u8 length,
123 const u8 *values);
124 extern s32
125 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
126 u8 command, u8 length, u8 *values);
127 #endif /* I2C */
128
129 enum i2c_alert_protocol {
130 I2C_PROTOCOL_SMBUS_ALERT,
131 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
132 };
133
134 /**
135 * struct i2c_driver - represent an I2C device driver
136 * @class: What kind of i2c device we instantiate (for detect)
137 * @attach_adapter: Callback for bus addition (deprecated)
138 * @probe: Callback for device binding
139 * @remove: Callback for device unbinding
140 * @shutdown: Callback for device shutdown
141 * @alert: Alert callback, for example for the SMBus alert protocol
142 * @command: Callback for bus-wide signaling (optional)
143 * @driver: Device driver model driver
144 * @id_table: List of I2C devices supported by this driver
145 * @detect: Callback for device detection
146 * @address_list: The I2C addresses to probe (for detect)
147 * @clients: List of detected clients we created (for i2c-core use only)
148 *
149 * The driver.owner field should be set to the module owner of this driver.
150 * The driver.name field should be set to the name of this driver.
151 *
152 * For automatic device detection, both @detect and @address_list must
153 * be defined. @class should also be set, otherwise only devices forced
154 * with module parameters will be created. The detect function must
155 * fill at least the name field of the i2c_board_info structure it is
156 * handed upon successful detection, and possibly also the flags field.
157 *
158 * If @detect is missing, the driver will still work fine for enumerated
159 * devices. Detected devices simply won't be supported. This is expected
160 * for the many I2C/SMBus devices which can't be detected reliably, and
161 * the ones which can always be enumerated in practice.
162 *
163 * The i2c_client structure which is handed to the @detect callback is
164 * not a real i2c_client. It is initialized just enough so that you can
165 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
166 * else with it. In particular, calling dev_dbg and friends on it is
167 * not allowed.
168 */
169 struct i2c_driver {
170 unsigned int class;
171
172 /* Notifies the driver that a new bus has appeared. You should avoid
173 * using this, it will be removed in a near future.
174 */
175 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
176
177 /* Standard driver model interfaces */
178 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
179 int (*remove)(struct i2c_client *);
180
181 /* driver model interfaces that don't relate to enumeration */
182 void (*shutdown)(struct i2c_client *);
183
184 /* Alert callback, for example for the SMBus alert protocol.
185 * The format and meaning of the data value depends on the protocol.
186 * For the SMBus alert protocol, there is a single bit of data passed
187 * as the alert response's low bit ("event flag").
188 * For the SMBus Host Notify protocol, the data corresponds to the
189 * 16-bit payload data reported by the slave device acting as master.
190 */
191 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
192 unsigned int data);
193
194 /* a ioctl like command that can be used to perform specific functions
195 * with the device.
196 */
197 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
198
199 struct device_driver driver;
200 const struct i2c_device_id *id_table;
201
202 /* Device detection callback for automatic device creation */
203 int (*detect)(struct i2c_client *, struct i2c_board_info *);
204 const unsigned short *address_list;
205 struct list_head clients;
206 };
207 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
208
209 /**
210 * struct i2c_client - represent an I2C slave device
211 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
212 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
213 * @addr: Address used on the I2C bus connected to the parent adapter.
214 * @name: Indicates the type of the device, usually a chip name that's
215 * generic enough to hide second-sourcing and compatible revisions.
216 * @adapter: manages the bus segment hosting this I2C device
217 * @dev: Driver model device node for the slave.
218 * @irq: indicates the IRQ generated by this device (if any)
219 * @detected: member of an i2c_driver.clients list or i2c-core's
220 * userspace_devices list
221 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
222 * calls it to pass on slave events to the slave driver.
223 *
224 * An i2c_client identifies a single device (i.e. chip) connected to an
225 * i2c bus. The behaviour exposed to Linux is defined by the driver
226 * managing the device.
227 */
228 struct i2c_client {
229 unsigned short flags; /* div., see below */
230 unsigned short addr; /* chip address - NOTE: 7bit */
231 /* addresses are stored in the */
232 /* _LOWER_ 7 bits */
233 char name[I2C_NAME_SIZE];
234 struct i2c_adapter *adapter; /* the adapter we sit on */
235 struct device dev; /* the device structure */
236 int irq; /* irq issued by device */
237 struct list_head detected;
238 #if IS_ENABLED(CONFIG_I2C_SLAVE)
239 i2c_slave_cb_t slave_cb; /* callback for slave mode */
240 #endif
241 };
242 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
243
244 extern struct i2c_client *i2c_verify_client(struct device *dev);
245 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
246
247 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
248 {
249 struct device * const dev = container_of(kobj, struct device, kobj);
250 return to_i2c_client(dev);
251 }
252
253 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
254 {
255 return dev_get_drvdata(&dev->dev);
256 }
257
258 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
259 {
260 dev_set_drvdata(&dev->dev, data);
261 }
262
263 /* I2C slave support */
264
265 #if IS_ENABLED(CONFIG_I2C_SLAVE)
266 enum i2c_slave_event {
267 I2C_SLAVE_READ_REQUESTED,
268 I2C_SLAVE_WRITE_REQUESTED,
269 I2C_SLAVE_READ_PROCESSED,
270 I2C_SLAVE_WRITE_RECEIVED,
271 I2C_SLAVE_STOP,
272 };
273
274 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
275 extern int i2c_slave_unregister(struct i2c_client *client);
276
277 static inline int i2c_slave_event(struct i2c_client *client,
278 enum i2c_slave_event event, u8 *val)
279 {
280 return client->slave_cb(client, event, val);
281 }
282 #endif
283
284 /**
285 * struct i2c_board_info - template for device creation
286 * @type: chip type, to initialize i2c_client.name
287 * @flags: to initialize i2c_client.flags
288 * @addr: stored in i2c_client.addr
289 * @platform_data: stored in i2c_client.dev.platform_data
290 * @archdata: copied into i2c_client.dev.archdata
291 * @of_node: pointer to OpenFirmware device node
292 * @fwnode: device node supplied by the platform firmware
293 * @irq: stored in i2c_client.irq
294 *
295 * I2C doesn't actually support hardware probing, although controllers and
296 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
297 * a device at a given address. Drivers commonly need more information than
298 * that, such as chip type, configuration, associated IRQ, and so on.
299 *
300 * i2c_board_info is used to build tables of information listing I2C devices
301 * that are present. This information is used to grow the driver model tree.
302 * For mainboards this is done statically using i2c_register_board_info();
303 * bus numbers identify adapters that aren't yet available. For add-on boards,
304 * i2c_new_device() does this dynamically with the adapter already known.
305 */
306 struct i2c_board_info {
307 char type[I2C_NAME_SIZE];
308 unsigned short flags;
309 unsigned short addr;
310 void *platform_data;
311 struct dev_archdata *archdata;
312 struct device_node *of_node;
313 struct fwnode_handle *fwnode;
314 int irq;
315 };
316
317 /**
318 * I2C_BOARD_INFO - macro used to list an i2c device and its address
319 * @dev_type: identifies the device type
320 * @dev_addr: the device's address on the bus.
321 *
322 * This macro initializes essential fields of a struct i2c_board_info,
323 * declaring what has been provided on a particular board. Optional
324 * fields (such as associated irq, or device-specific platform_data)
325 * are provided using conventional syntax.
326 */
327 #define I2C_BOARD_INFO(dev_type, dev_addr) \
328 .type = dev_type, .addr = (dev_addr)
329
330
331 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
332 /* Add-on boards should register/unregister their devices; e.g. a board
333 * with integrated I2C, a config eeprom, sensors, and a codec that's
334 * used in conjunction with the primary hardware.
335 */
336 extern struct i2c_client *
337 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
338
339 /* If you don't know the exact address of an I2C device, use this variant
340 * instead, which can probe for device presence in a list of possible
341 * addresses. The "probe" callback function is optional. If it is provided,
342 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
343 * a default probing method is used.
344 */
345 extern struct i2c_client *
346 i2c_new_probed_device(struct i2c_adapter *adap,
347 struct i2c_board_info *info,
348 unsigned short const *addr_list,
349 int (*probe)(struct i2c_adapter *, unsigned short addr));
350
351 /* Common custom probe functions */
352 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
353
354 /* For devices that use several addresses, use i2c_new_dummy() to make
355 * client handles for the extra addresses.
356 */
357 extern struct i2c_client *
358 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
359
360 extern struct i2c_client *
361 i2c_new_secondary_device(struct i2c_client *client,
362 const char *name,
363 u16 default_addr);
364
365 extern void i2c_unregister_device(struct i2c_client *);
366 #endif /* I2C */
367
368 /* Mainboard arch_initcall() code should register all its I2C devices.
369 * This is done at arch_initcall time, before declaring any i2c adapters.
370 * Modules for add-on boards must use other calls.
371 */
372 #ifdef CONFIG_I2C_BOARDINFO
373 extern int
374 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
375 unsigned n);
376 #else
377 static inline int
378 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
379 unsigned n)
380 {
381 return 0;
382 }
383 #endif /* I2C_BOARDINFO */
384
385 /**
386 * struct i2c_algorithm - represent I2C transfer method
387 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
388 * defined by the msgs array, with num messages available to transfer via
389 * the adapter specified by adap.
390 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
391 * is not present, then the bus layer will try and convert the SMBus calls
392 * into I2C transfers instead.
393 * @functionality: Return the flags that this algorithm/adapter pair supports
394 * from the I2C_FUNC_* flags.
395 * @reg_slave: Register given client to I2C slave mode of this adapter
396 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
397 *
398 * The following structs are for those who like to implement new bus drivers:
399 * i2c_algorithm is the interface to a class of hardware solutions which can
400 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
401 * to name two of the most common.
402 *
403 * The return codes from the @master_xfer field should indicate the type of
404 * error code that occurred during the transfer, as documented in the kernel
405 * Documentation file Documentation/i2c/fault-codes.
406 */
407 struct i2c_algorithm {
408 /* If an adapter algorithm can't do I2C-level access, set master_xfer
409 to NULL. If an adapter algorithm can do SMBus access, set
410 smbus_xfer. If set to NULL, the SMBus protocol is simulated
411 using common I2C messages */
412 /* master_xfer should return the number of messages successfully
413 processed, or a negative value on error */
414 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
415 int num);
416 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
417 unsigned short flags, char read_write,
418 u8 command, int size, union i2c_smbus_data *data);
419
420 /* To determine what the adapter supports */
421 u32 (*functionality) (struct i2c_adapter *);
422
423 #if IS_ENABLED(CONFIG_I2C_SLAVE)
424 int (*reg_slave)(struct i2c_client *client);
425 int (*unreg_slave)(struct i2c_client *client);
426 #endif
427 };
428
429 /**
430 * struct i2c_timings - I2C timing information
431 * @bus_freq_hz: the bus frequency in Hz
432 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
433 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
434 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
435 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
436 */
437 struct i2c_timings {
438 u32 bus_freq_hz;
439 u32 scl_rise_ns;
440 u32 scl_fall_ns;
441 u32 scl_int_delay_ns;
442 u32 sda_fall_ns;
443 };
444
445 /**
446 * struct i2c_bus_recovery_info - I2C bus recovery information
447 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
448 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
449 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
450 * recovery. Used internally for generic GPIO recovery.
451 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
452 * internally for generic GPIO recovery.
453 * @get_sda: This gets current value of SDA line. Optional for generic SCL
454 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
455 * recovery.
456 * @prepare_recovery: This will be called before starting recovery. Platform may
457 * configure padmux here for SDA/SCL line or something else they want.
458 * @unprepare_recovery: This will be called after completing recovery. Platform
459 * may configure padmux here for SDA/SCL line or something else they want.
460 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
461 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
462 */
463 struct i2c_bus_recovery_info {
464 int (*recover_bus)(struct i2c_adapter *);
465
466 int (*get_scl)(struct i2c_adapter *);
467 void (*set_scl)(struct i2c_adapter *, int val);
468 int (*get_sda)(struct i2c_adapter *);
469
470 void (*prepare_recovery)(struct i2c_adapter *);
471 void (*unprepare_recovery)(struct i2c_adapter *);
472
473 /* gpio recovery */
474 int scl_gpio;
475 int sda_gpio;
476 };
477
478 int i2c_recover_bus(struct i2c_adapter *adap);
479
480 /* Generic recovery routines */
481 int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
482 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
483
484 /**
485 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
486 * @flags: see I2C_AQ_* for possible flags and read below
487 * @max_num_msgs: maximum number of messages per transfer
488 * @max_write_len: maximum length of a write message
489 * @max_read_len: maximum length of a read message
490 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
491 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
492 *
493 * Note about combined messages: Some I2C controllers can only send one message
494 * per transfer, plus something called combined message or write-then-read.
495 * This is (usually) a small write message followed by a read message and
496 * barely enough to access register based devices like EEPROMs. There is a flag
497 * to support this mode. It implies max_num_msg = 2 and does the length checks
498 * with max_comb_*_len because combined message mode usually has its own
499 * limitations. Because of HW implementations, some controllers can actually do
500 * write-then-anything or other variants. To support that, write-then-read has
501 * been broken out into smaller bits like write-first and read-second which can
502 * be combined as needed.
503 */
504
505 struct i2c_adapter_quirks {
506 u64 flags;
507 int max_num_msgs;
508 u16 max_write_len;
509 u16 max_read_len;
510 u16 max_comb_1st_msg_len;
511 u16 max_comb_2nd_msg_len;
512 };
513
514 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
515 #define I2C_AQ_COMB BIT(0)
516 /* first combined message must be write */
517 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
518 /* second combined message must be read */
519 #define I2C_AQ_COMB_READ_SECOND BIT(2)
520 /* both combined messages must have the same target address */
521 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
522 /* convenience macro for typical write-then read case */
523 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
524 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
525 /* clock stretching is not supported */
526 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
527
528 /*
529 * i2c_adapter is the structure used to identify a physical i2c bus along
530 * with the access algorithms necessary to access it.
531 */
532 struct i2c_adapter {
533 struct module *owner;
534 unsigned int class; /* classes to allow probing for */
535 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
536 void *algo_data;
537
538 /* data fields that are valid for all devices */
539 struct rt_mutex bus_lock;
540 struct rt_mutex mux_lock;
541
542 int timeout; /* in jiffies */
543 int retries;
544 struct device dev; /* the adapter device */
545
546 int nr;
547 char name[48];
548 struct completion dev_released;
549
550 struct mutex userspace_clients_lock;
551 struct list_head userspace_clients;
552
553 struct i2c_bus_recovery_info *bus_recovery_info;
554 const struct i2c_adapter_quirks *quirks;
555
556 void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
557 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
558 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
559 };
560 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
561
562 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
563 {
564 return dev_get_drvdata(&dev->dev);
565 }
566
567 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
568 {
569 dev_set_drvdata(&dev->dev, data);
570 }
571
572 static inline struct i2c_adapter *
573 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
574 {
575 #if IS_ENABLED(CONFIG_I2C_MUX)
576 struct device *parent = adapter->dev.parent;
577
578 if (parent != NULL && parent->type == &i2c_adapter_type)
579 return to_i2c_adapter(parent);
580 else
581 #endif
582 return NULL;
583 }
584
585 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
586
587 /* Adapter locking functions, exported for shared pin cases */
588 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
589 #define I2C_LOCK_SEGMENT BIT(1)
590
591 /**
592 * i2c_lock_bus - Get exclusive access to an I2C bus segment
593 * @adapter: Target I2C bus segment
594 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
595 * locks only this branch in the adapter tree
596 */
597 static inline void
598 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
599 {
600 adapter->lock_bus(adapter, flags);
601 }
602
603 /**
604 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
605 * @adapter: Target I2C bus segment
606 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
607 * unlocks only this branch in the adapter tree
608 */
609 static inline void
610 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
611 {
612 adapter->unlock_bus(adapter, flags);
613 }
614
615 static inline void
616 i2c_lock_adapter(struct i2c_adapter *adapter)
617 {
618 i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
619 }
620
621 static inline void
622 i2c_unlock_adapter(struct i2c_adapter *adapter)
623 {
624 i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
625 }
626
627 /*flags for the client struct: */
628 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
629 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
630 /* Must equal I2C_M_TEN below */
631 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
632 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
633 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
634 /* Must match I2C_M_STOP|IGNORE_NAK */
635
636 /* i2c adapter classes (bitmask) */
637 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
638 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
639 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
640 #define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
641
642 /* Internal numbers to terminate lists */
643 #define I2C_CLIENT_END 0xfffeU
644
645 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
646 #define I2C_ADDRS(addr, addrs...) \
647 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
648
649
650 /* ----- functions exported by i2c.o */
651
652 /* administration...
653 */
654 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
655 extern int i2c_add_adapter(struct i2c_adapter *);
656 extern void i2c_del_adapter(struct i2c_adapter *);
657 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
658
659 extern int i2c_register_driver(struct module *, struct i2c_driver *);
660 extern void i2c_del_driver(struct i2c_driver *);
661
662 /* use a define to avoid include chaining to get THIS_MODULE */
663 #define i2c_add_driver(driver) \
664 i2c_register_driver(THIS_MODULE, driver)
665
666 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
667 extern void i2c_release_client(struct i2c_client *client);
668
669 /* call the i2c_client->command() of all attached clients with
670 * the given arguments */
671 extern void i2c_clients_command(struct i2c_adapter *adap,
672 unsigned int cmd, void *arg);
673
674 extern struct i2c_adapter *i2c_get_adapter(int nr);
675 extern void i2c_put_adapter(struct i2c_adapter *adap);
676
677 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
678
679 /* Return the functionality mask */
680 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
681 {
682 return adap->algo->functionality(adap);
683 }
684
685 /* Return 1 if adapter supports everything we need, 0 if not. */
686 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
687 {
688 return (func & i2c_get_functionality(adap)) == func;
689 }
690
691 /**
692 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
693 * @adap: i2c adapter
694 * @quirks: quirk flags
695 *
696 * Return: true if the adapter has all the specified quirk flags, false if not
697 */
698 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
699 {
700 if (!adap->quirks)
701 return false;
702 return (adap->quirks->flags & quirks) == quirks;
703 }
704
705 /* Return the adapter number for a specific adapter */
706 static inline int i2c_adapter_id(struct i2c_adapter *adap)
707 {
708 return adap->nr;
709 }
710
711 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
712 {
713 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
714 }
715
716 /**
717 * module_i2c_driver() - Helper macro for registering a modular I2C driver
718 * @__i2c_driver: i2c_driver struct
719 *
720 * Helper macro for I2C drivers which do not do anything special in module
721 * init/exit. This eliminates a lot of boilerplate. Each module may only
722 * use this macro once, and calling it replaces module_init() and module_exit()
723 */
724 #define module_i2c_driver(__i2c_driver) \
725 module_driver(__i2c_driver, i2c_add_driver, \
726 i2c_del_driver)
727
728 /**
729 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
730 * @__i2c_driver: i2c_driver struct
731 *
732 * Helper macro for I2C drivers which do not do anything special in their
733 * init. This eliminates a lot of boilerplate. Each driver may only
734 * use this macro once, and calling it replaces device_initcall().
735 */
736 #define builtin_i2c_driver(__i2c_driver) \
737 builtin_driver(__i2c_driver, i2c_add_driver)
738
739 #endif /* I2C */
740
741 #if IS_ENABLED(CONFIG_OF)
742 /* must call put_device() when done with returned i2c_client device */
743 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
744
745 /* must call put_device() when done with returned i2c_adapter device */
746 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
747
748 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
749 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
750
751 #else
752
753 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
754 {
755 return NULL;
756 }
757
758 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
759 {
760 return NULL;
761 }
762
763 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
764 {
765 return NULL;
766 }
767 #endif /* CONFIG_OF */
768
769 #endif /* _LINUX_I2C_H */
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