xref: /openbmc/linux/include/linux/i2c.h (revision fa7f32422ea1ac276b45b96a540ed5981caaa61f)
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_lock_operations - represent I2C locking operations
431  * @lock_bus: Get exclusive access to an I2C bus segment
432  * @trylock_bus: Try to get exclusive access to an I2C bus segment
433  * @unlock_bus: Release exclusive access to an I2C bus segment
434  *
435  * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
436  */
437 struct i2c_lock_operations {
438 	void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
439 	int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
440 	void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
441 };
442 
443 /**
444  * struct i2c_timings - I2C timing information
445  * @bus_freq_hz: the bus frequency in Hz
446  * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
447  * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
448  * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
449  * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
450  */
451 struct i2c_timings {
452 	u32 bus_freq_hz;
453 	u32 scl_rise_ns;
454 	u32 scl_fall_ns;
455 	u32 scl_int_delay_ns;
456 	u32 sda_fall_ns;
457 };
458 
459 /**
460  * struct i2c_bus_recovery_info - I2C bus recovery information
461  * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
462  *	i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
463  * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
464  *      recovery. Used internally for generic GPIO recovery.
465  * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
466  *      internally for generic GPIO recovery.
467  * @get_sda: This gets current value of SDA line. Optional for generic SCL
468  *      recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
469  *      recovery.
470  * @prepare_recovery: This will be called before starting recovery. Platform may
471  *	configure padmux here for SDA/SCL line or something else they want.
472  * @unprepare_recovery: This will be called after completing recovery. Platform
473  *	may configure padmux here for SDA/SCL line or something else they want.
474  * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
475  * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
476  */
477 struct i2c_bus_recovery_info {
478 	int (*recover_bus)(struct i2c_adapter *);
479 
480 	int (*get_scl)(struct i2c_adapter *);
481 	void (*set_scl)(struct i2c_adapter *, int val);
482 	int (*get_sda)(struct i2c_adapter *);
483 
484 	void (*prepare_recovery)(struct i2c_adapter *);
485 	void (*unprepare_recovery)(struct i2c_adapter *);
486 
487 	/* gpio recovery */
488 	int scl_gpio;
489 	int sda_gpio;
490 };
491 
492 int i2c_recover_bus(struct i2c_adapter *adap);
493 
494 /* Generic recovery routines */
495 int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
496 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
497 
498 /**
499  * struct i2c_adapter_quirks - describe flaws of an i2c adapter
500  * @flags: see I2C_AQ_* for possible flags and read below
501  * @max_num_msgs: maximum number of messages per transfer
502  * @max_write_len: maximum length of a write message
503  * @max_read_len: maximum length of a read message
504  * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
505  * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
506  *
507  * Note about combined messages: Some I2C controllers can only send one message
508  * per transfer, plus something called combined message or write-then-read.
509  * This is (usually) a small write message followed by a read message and
510  * barely enough to access register based devices like EEPROMs. There is a flag
511  * to support this mode. It implies max_num_msg = 2 and does the length checks
512  * with max_comb_*_len because combined message mode usually has its own
513  * limitations. Because of HW implementations, some controllers can actually do
514  * write-then-anything or other variants. To support that, write-then-read has
515  * been broken out into smaller bits like write-first and read-second which can
516  * be combined as needed.
517  */
518 
519 struct i2c_adapter_quirks {
520 	u64 flags;
521 	int max_num_msgs;
522 	u16 max_write_len;
523 	u16 max_read_len;
524 	u16 max_comb_1st_msg_len;
525 	u16 max_comb_2nd_msg_len;
526 };
527 
528 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
529 #define I2C_AQ_COMB			BIT(0)
530 /* first combined message must be write */
531 #define I2C_AQ_COMB_WRITE_FIRST		BIT(1)
532 /* second combined message must be read */
533 #define I2C_AQ_COMB_READ_SECOND		BIT(2)
534 /* both combined messages must have the same target address */
535 #define I2C_AQ_COMB_SAME_ADDR		BIT(3)
536 /* convenience macro for typical write-then read case */
537 #define I2C_AQ_COMB_WRITE_THEN_READ	(I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
538 					 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
539 /* clock stretching is not supported */
540 #define I2C_AQ_NO_CLK_STRETCH		BIT(4)
541 
542 /*
543  * i2c_adapter is the structure used to identify a physical i2c bus along
544  * with the access algorithms necessary to access it.
545  */
546 struct i2c_adapter {
547 	struct module *owner;
548 	unsigned int class;		  /* classes to allow probing for */
549 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
550 	void *algo_data;
551 
552 	/* data fields that are valid for all devices	*/
553 	const struct i2c_lock_operations *lock_ops;
554 	struct rt_mutex bus_lock;
555 	struct rt_mutex mux_lock;
556 
557 	int timeout;			/* in jiffies */
558 	int retries;
559 	struct device dev;		/* the adapter device */
560 
561 	int nr;
562 	char name[48];
563 	struct completion dev_released;
564 
565 	struct mutex userspace_clients_lock;
566 	struct list_head userspace_clients;
567 
568 	struct i2c_bus_recovery_info *bus_recovery_info;
569 	const struct i2c_adapter_quirks *quirks;
570 };
571 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
572 
573 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
574 {
575 	return dev_get_drvdata(&dev->dev);
576 }
577 
578 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
579 {
580 	dev_set_drvdata(&dev->dev, data);
581 }
582 
583 static inline struct i2c_adapter *
584 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
585 {
586 #if IS_ENABLED(CONFIG_I2C_MUX)
587 	struct device *parent = adapter->dev.parent;
588 
589 	if (parent != NULL && parent->type == &i2c_adapter_type)
590 		return to_i2c_adapter(parent);
591 	else
592 #endif
593 		return NULL;
594 }
595 
596 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
597 
598 /* Adapter locking functions, exported for shared pin cases */
599 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
600 #define I2C_LOCK_SEGMENT      BIT(1)
601 
602 /**
603  * i2c_lock_bus - Get exclusive access to an I2C bus segment
604  * @adapter: Target I2C bus segment
605  * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
606  *	locks only this branch in the adapter tree
607  */
608 static inline void
609 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
610 {
611 	adapter->lock_ops->lock_bus(adapter, flags);
612 }
613 
614 /**
615  * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
616  * @adapter: Target I2C bus segment
617  * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
618  *	I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
619  *
620  * Return: true if the I2C bus segment is locked, false otherwise
621  */
622 static inline int
623 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
624 {
625 	return adapter->lock_ops->trylock_bus(adapter, flags);
626 }
627 
628 /**
629  * i2c_unlock_bus - Release exclusive access to an I2C bus segment
630  * @adapter: Target I2C bus segment
631  * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
632  *	unlocks only this branch in the adapter tree
633  */
634 static inline void
635 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
636 {
637 	adapter->lock_ops->unlock_bus(adapter, flags);
638 }
639 
640 static inline void
641 i2c_lock_adapter(struct i2c_adapter *adapter)
642 {
643 	i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
644 }
645 
646 static inline void
647 i2c_unlock_adapter(struct i2c_adapter *adapter)
648 {
649 	i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
650 }
651 
652 /*flags for the client struct: */
653 #define I2C_CLIENT_PEC		0x04	/* Use Packet Error Checking */
654 #define I2C_CLIENT_TEN		0x10	/* we have a ten bit chip address */
655 					/* Must equal I2C_M_TEN below */
656 #define I2C_CLIENT_SLAVE	0x20	/* we are the slave */
657 #define I2C_CLIENT_WAKE		0x80	/* for board_info; true iff can wake */
658 #define I2C_CLIENT_SCCB		0x9000	/* Use Omnivision SCCB protocol */
659 					/* Must match I2C_M_STOP|IGNORE_NAK */
660 
661 /* i2c adapter classes (bitmask) */
662 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
663 #define I2C_CLASS_DDC		(1<<3)	/* DDC bus on graphics adapters */
664 #define I2C_CLASS_SPD		(1<<7)	/* Memory modules */
665 #define I2C_CLASS_DEPRECATED	(1<<8)	/* Warn users that adapter will stop using classes */
666 
667 /* Internal numbers to terminate lists */
668 #define I2C_CLIENT_END		0xfffeU
669 
670 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
671 #define I2C_ADDRS(addr, addrs...) \
672 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
673 
674 
675 /* ----- functions exported by i2c.o */
676 
677 /* administration...
678  */
679 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
680 extern int i2c_add_adapter(struct i2c_adapter *);
681 extern void i2c_del_adapter(struct i2c_adapter *);
682 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
683 
684 extern int i2c_register_driver(struct module *, struct i2c_driver *);
685 extern void i2c_del_driver(struct i2c_driver *);
686 
687 /* use a define to avoid include chaining to get THIS_MODULE */
688 #define i2c_add_driver(driver) \
689 	i2c_register_driver(THIS_MODULE, driver)
690 
691 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
692 extern void i2c_release_client(struct i2c_client *client);
693 
694 /* call the i2c_client->command() of all attached clients with
695  * the given arguments */
696 extern void i2c_clients_command(struct i2c_adapter *adap,
697 				unsigned int cmd, void *arg);
698 
699 extern struct i2c_adapter *i2c_get_adapter(int nr);
700 extern void i2c_put_adapter(struct i2c_adapter *adap);
701 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
702 
703 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
704 
705 /* Return the functionality mask */
706 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
707 {
708 	return adap->algo->functionality(adap);
709 }
710 
711 /* Return 1 if adapter supports everything we need, 0 if not. */
712 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
713 {
714 	return (func & i2c_get_functionality(adap)) == func;
715 }
716 
717 /**
718  * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
719  * @adap: i2c adapter
720  * @quirks: quirk flags
721  *
722  * Return: true if the adapter has all the specified quirk flags, false if not
723  */
724 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
725 {
726 	if (!adap->quirks)
727 		return false;
728 	return (adap->quirks->flags & quirks) == quirks;
729 }
730 
731 /* Return the adapter number for a specific adapter */
732 static inline int i2c_adapter_id(struct i2c_adapter *adap)
733 {
734 	return adap->nr;
735 }
736 
737 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
738 {
739 	return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
740 }
741 
742 /**
743  * module_i2c_driver() - Helper macro for registering a modular I2C driver
744  * @__i2c_driver: i2c_driver struct
745  *
746  * Helper macro for I2C drivers which do not do anything special in module
747  * init/exit. This eliminates a lot of boilerplate. Each module may only
748  * use this macro once, and calling it replaces module_init() and module_exit()
749  */
750 #define module_i2c_driver(__i2c_driver) \
751 	module_driver(__i2c_driver, i2c_add_driver, \
752 			i2c_del_driver)
753 
754 /**
755  * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
756  * @__i2c_driver: i2c_driver struct
757  *
758  * Helper macro for I2C drivers which do not do anything special in their
759  * init. This eliminates a lot of boilerplate. Each driver may only
760  * use this macro once, and calling it replaces device_initcall().
761  */
762 #define builtin_i2c_driver(__i2c_driver) \
763 	builtin_driver(__i2c_driver, i2c_add_driver)
764 
765 #endif /* I2C */
766 
767 #if IS_ENABLED(CONFIG_OF)
768 /* must call put_device() when done with returned i2c_client device */
769 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
770 
771 /* must call put_device() when done with returned i2c_adapter device */
772 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
773 
774 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
775 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
776 
777 #else
778 
779 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
780 {
781 	return NULL;
782 }
783 
784 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
785 {
786 	return NULL;
787 }
788 
789 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
790 {
791 	return NULL;
792 }
793 #endif /* CONFIG_OF */
794 
795 #if IS_ENABLED(CONFIG_ACPI)
796 u32 i2c_acpi_find_bus_speed(struct device *dev);
797 #else
798 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
799 {
800 	return 0;
801 }
802 #endif /* CONFIG_ACPI */
803 
804 #endif /* _LINUX_I2C_H */
805