Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-or-later */
2 : /*
3 : * i2c.h - definitions for the Linux i2c bus interface
4 : * Copyright (C) 1995-2000 Simon G. Vogl
5 : * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org>
6 : *
7 : * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
8 : * Frodo Looijaard <frodol@dds.nl>
9 : */
10 : #ifndef _LINUX_I2C_H
11 : #define _LINUX_I2C_H
12 :
13 : #include <linux/acpi.h> /* for acpi_handle */
14 : #include <linux/bits.h>
15 : #include <linux/mod_devicetable.h>
16 : #include <linux/device.h> /* for struct device */
17 : #include <linux/sched.h> /* for completion */
18 : #include <linux/mutex.h>
19 : #include <linux/regulator/consumer.h>
20 : #include <linux/rtmutex.h>
21 : #include <linux/irqdomain.h> /* for Host Notify IRQ */
22 : #include <linux/of.h> /* for struct device_node */
23 : #include <linux/swab.h> /* for swab16 */
24 : #include <uapi/linux/i2c.h>
25 :
26 : extern struct bus_type i2c_bus_type;
27 : extern struct device_type i2c_adapter_type;
28 : extern struct device_type i2c_client_type;
29 :
30 : /* --- General options ------------------------------------------------ */
31 :
32 : struct i2c_msg;
33 : struct i2c_algorithm;
34 : struct i2c_adapter;
35 : struct i2c_client;
36 : struct i2c_driver;
37 : struct i2c_device_identity;
38 : union i2c_smbus_data;
39 : struct i2c_board_info;
40 : enum i2c_slave_event;
41 : typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
42 : enum i2c_slave_event event, u8 *val);
43 :
44 : /* I2C Frequency Modes */
45 : #define I2C_MAX_STANDARD_MODE_FREQ 100000
46 : #define I2C_MAX_FAST_MODE_FREQ 400000
47 : #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
48 : #define I2C_MAX_TURBO_MODE_FREQ 1400000
49 : #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
50 : #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
51 :
52 : struct module;
53 : struct property_entry;
54 :
55 : #if IS_ENABLED(CONFIG_I2C)
56 : /* Return the Frequency mode string based on the bus frequency */
57 : const char *i2c_freq_mode_string(u32 bus_freq_hz);
58 :
59 : /*
60 : * The master routines are the ones normally used to transmit data to devices
61 : * on a bus (or read from them). Apart from two basic transfer functions to
62 : * transmit one message at a time, a more complex version can be used to
63 : * transmit an arbitrary number of messages without interruption.
64 : * @count must be less than 64k since msg.len is u16.
65 : */
66 : int i2c_transfer_buffer_flags(const struct i2c_client *client,
67 : char *buf, int count, u16 flags);
68 :
69 : /**
70 : * i2c_master_recv - issue a single I2C message in master receive mode
71 : * @client: Handle to slave device
72 : * @buf: Where to store data read from slave
73 : * @count: How many bytes to read, must be less than 64k since msg.len is u16
74 : *
75 : * Returns negative errno, or else the number of bytes read.
76 : */
77 : static inline int i2c_master_recv(const struct i2c_client *client,
78 : char *buf, int count)
79 : {
80 : return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
81 : };
82 :
83 : /**
84 : * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
85 : * using a DMA safe buffer
86 : * @client: Handle to slave device
87 : * @buf: Where to store data read from slave, must be safe to use with DMA
88 : * @count: How many bytes to read, must be less than 64k since msg.len is u16
89 : *
90 : * Returns negative errno, or else the number of bytes read.
91 : */
92 : static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
93 : char *buf, int count)
94 : {
95 : return i2c_transfer_buffer_flags(client, buf, count,
96 : I2C_M_RD | I2C_M_DMA_SAFE);
97 : };
98 :
99 : /**
100 : * i2c_master_send - issue a single I2C message in master transmit mode
101 : * @client: Handle to slave device
102 : * @buf: Data that will be written to the slave
103 : * @count: How many bytes to write, must be less than 64k since msg.len is u16
104 : *
105 : * Returns negative errno, or else the number of bytes written.
106 : */
107 : static inline int i2c_master_send(const struct i2c_client *client,
108 : const char *buf, int count)
109 : {
110 : return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
111 : };
112 :
113 : /**
114 : * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
115 : * using a DMA safe buffer
116 : * @client: Handle to slave device
117 : * @buf: Data that will be written to the slave, must be safe to use with DMA
118 : * @count: How many bytes to write, must be less than 64k since msg.len is u16
119 : *
120 : * Returns negative errno, or else the number of bytes written.
121 : */
122 : static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
123 : const char *buf, int count)
124 : {
125 : return i2c_transfer_buffer_flags(client, (char *)buf, count,
126 : I2C_M_DMA_SAFE);
127 : };
128 :
129 : /* Transfer num messages.
130 : */
131 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
132 : /* Unlocked flavor */
133 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
134 :
135 : /* This is the very generalized SMBus access routine. You probably do not
136 : want to use this, though; one of the functions below may be much easier,
137 : and probably just as fast.
138 : Note that we use i2c_adapter here, because you do not need a specific
139 : smbus adapter to call this function. */
140 : s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
141 : unsigned short flags, char read_write, u8 command,
142 : int protocol, union i2c_smbus_data *data);
143 :
144 : /* Unlocked flavor */
145 : s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
146 : unsigned short flags, char read_write, u8 command,
147 : int protocol, union i2c_smbus_data *data);
148 :
149 : /* Now follow the 'nice' access routines. These also document the calling
150 : conventions of i2c_smbus_xfer. */
151 :
152 : u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
153 : s32 i2c_smbus_read_byte(const struct i2c_client *client);
154 : s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
155 : s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
156 : s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
157 : u8 command, u8 value);
158 : s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
159 : s32 i2c_smbus_write_word_data(const struct i2c_client *client,
160 : u8 command, u16 value);
161 :
162 : static inline s32
163 : i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
164 : {
165 : s32 value = i2c_smbus_read_word_data(client, command);
166 :
167 : return (value < 0) ? value : swab16(value);
168 : }
169 :
170 : static inline s32
171 : i2c_smbus_write_word_swapped(const struct i2c_client *client,
172 : u8 command, u16 value)
173 : {
174 : return i2c_smbus_write_word_data(client, command, swab16(value));
175 : }
176 :
177 : /* Returns the number of read bytes */
178 : s32 i2c_smbus_read_block_data(const struct i2c_client *client,
179 : u8 command, u8 *values);
180 : s32 i2c_smbus_write_block_data(const struct i2c_client *client,
181 : u8 command, u8 length, const u8 *values);
182 : /* Returns the number of read bytes */
183 : s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
184 : u8 command, u8 length, u8 *values);
185 : s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
186 : u8 command, u8 length, const u8 *values);
187 : s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
188 : u8 command, u8 length,
189 : u8 *values);
190 : int i2c_get_device_id(const struct i2c_client *client,
191 : struct i2c_device_identity *id);
192 : const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client);
193 : #endif /* I2C */
194 :
195 : /**
196 : * struct i2c_device_identity - i2c client device identification
197 : * @manufacturer_id: 0 - 4095, database maintained by NXP
198 : * @part_id: 0 - 511, according to manufacturer
199 : * @die_revision: 0 - 7, according to manufacturer
200 : */
201 : struct i2c_device_identity {
202 : u16 manufacturer_id;
203 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
204 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
205 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
206 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
207 : #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
208 : #define I2C_DEVICE_ID_ANALOG_DEVICES 5
209 : #define I2C_DEVICE_ID_STMICROELECTRONICS 6
210 : #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
211 : #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
212 : #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
213 : #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
214 : #define I2C_DEVICE_ID_FLIR 11
215 : #define I2C_DEVICE_ID_O2MICRO 12
216 : #define I2C_DEVICE_ID_ATMEL 13
217 : #define I2C_DEVICE_ID_NONE 0xffff
218 : u16 part_id;
219 : u8 die_revision;
220 : };
221 :
222 : enum i2c_alert_protocol {
223 : I2C_PROTOCOL_SMBUS_ALERT,
224 : I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
225 : };
226 :
227 : /**
228 : * enum i2c_driver_flags - Flags for an I2C device driver
229 : *
230 : * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe
231 : */
232 : enum i2c_driver_flags {
233 : I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0),
234 : };
235 :
236 : /**
237 : * struct i2c_driver - represent an I2C device driver
238 : * @class: What kind of i2c device we instantiate (for detect)
239 : * @probe: Callback for device binding
240 : * @probe_new: Transitional callback for device binding - do not use
241 : * @remove: Callback for device unbinding
242 : * @shutdown: Callback for device shutdown
243 : * @alert: Alert callback, for example for the SMBus alert protocol
244 : * @command: Callback for bus-wide signaling (optional)
245 : * @driver: Device driver model driver
246 : * @id_table: List of I2C devices supported by this driver
247 : * @detect: Callback for device detection
248 : * @address_list: The I2C addresses to probe (for detect)
249 : * @clients: List of detected clients we created (for i2c-core use only)
250 : * @flags: A bitmask of flags defined in &enum i2c_driver_flags
251 : *
252 : * The driver.owner field should be set to the module owner of this driver.
253 : * The driver.name field should be set to the name of this driver.
254 : *
255 : * For automatic device detection, both @detect and @address_list must
256 : * be defined. @class should also be set, otherwise only devices forced
257 : * with module parameters will be created. The detect function must
258 : * fill at least the name field of the i2c_board_info structure it is
259 : * handed upon successful detection, and possibly also the flags field.
260 : *
261 : * If @detect is missing, the driver will still work fine for enumerated
262 : * devices. Detected devices simply won't be supported. This is expected
263 : * for the many I2C/SMBus devices which can't be detected reliably, and
264 : * the ones which can always be enumerated in practice.
265 : *
266 : * The i2c_client structure which is handed to the @detect callback is
267 : * not a real i2c_client. It is initialized just enough so that you can
268 : * call i2c_smbus_read_byte_data and friends on it. Don't do anything
269 : * else with it. In particular, calling dev_dbg and friends on it is
270 : * not allowed.
271 : */
272 : struct i2c_driver {
273 : unsigned int class;
274 :
275 : union {
276 : /* Standard driver model interfaces */
277 : int (*probe)(struct i2c_client *client);
278 : /*
279 : * Legacy callback that was part of a conversion of .probe().
280 : * Today it has the same semantic as .probe(). Don't use for new
281 : * code.
282 : */
283 : int (*probe_new)(struct i2c_client *client);
284 : };
285 : void (*remove)(struct i2c_client *client);
286 :
287 :
288 : /* driver model interfaces that don't relate to enumeration */
289 : void (*shutdown)(struct i2c_client *client);
290 :
291 : /* Alert callback, for example for the SMBus alert protocol.
292 : * The format and meaning of the data value depends on the protocol.
293 : * For the SMBus alert protocol, there is a single bit of data passed
294 : * as the alert response's low bit ("event flag").
295 : * For the SMBus Host Notify protocol, the data corresponds to the
296 : * 16-bit payload data reported by the slave device acting as master.
297 : */
298 : void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
299 : unsigned int data);
300 :
301 : /* a ioctl like command that can be used to perform specific functions
302 : * with the device.
303 : */
304 : int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
305 :
306 : struct device_driver driver;
307 : const struct i2c_device_id *id_table;
308 :
309 : /* Device detection callback for automatic device creation */
310 : int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
311 : const unsigned short *address_list;
312 : struct list_head clients;
313 :
314 : u32 flags;
315 : };
316 : #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
317 :
318 : /**
319 : * struct i2c_client - represent an I2C slave device
320 : * @flags: see I2C_CLIENT_* for possible flags
321 : * @addr: Address used on the I2C bus connected to the parent adapter.
322 : * @name: Indicates the type of the device, usually a chip name that's
323 : * generic enough to hide second-sourcing and compatible revisions.
324 : * @adapter: manages the bus segment hosting this I2C device
325 : * @dev: Driver model device node for the slave.
326 : * @init_irq: IRQ that was set at initialization
327 : * @irq: indicates the IRQ generated by this device (if any)
328 : * @detected: member of an i2c_driver.clients list or i2c-core's
329 : * userspace_devices list
330 : * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
331 : * calls it to pass on slave events to the slave driver.
332 : * @devres_group_id: id of the devres group that will be created for resources
333 : * acquired when probing this device.
334 : *
335 : * An i2c_client identifies a single device (i.e. chip) connected to an
336 : * i2c bus. The behaviour exposed to Linux is defined by the driver
337 : * managing the device.
338 : */
339 : struct i2c_client {
340 : unsigned short flags; /* div., see below */
341 : #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
342 : #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
343 : /* Must equal I2C_M_TEN below */
344 : #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
345 : #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
346 : #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
347 : #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
348 : /* Must match I2C_M_STOP|IGNORE_NAK */
349 :
350 : unsigned short addr; /* chip address - NOTE: 7bit */
351 : /* addresses are stored in the */
352 : /* _LOWER_ 7 bits */
353 : char name[I2C_NAME_SIZE];
354 : struct i2c_adapter *adapter; /* the adapter we sit on */
355 : struct device dev; /* the device structure */
356 : int init_irq; /* irq set at initialization */
357 : int irq; /* irq issued by device */
358 : struct list_head detected;
359 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
360 : i2c_slave_cb_t slave_cb; /* callback for slave mode */
361 : #endif
362 : void *devres_group_id; /* ID of probe devres group */
363 : };
364 : #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
365 :
366 : struct i2c_adapter *i2c_verify_adapter(struct device *dev);
367 : const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
368 : const struct i2c_client *client);
369 :
370 : const void *i2c_get_match_data(const struct i2c_client *client);
371 :
372 : static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
373 : {
374 : struct device * const dev = kobj_to_dev(kobj);
375 : return to_i2c_client(dev);
376 : }
377 :
378 : static inline void *i2c_get_clientdata(const struct i2c_client *client)
379 : {
380 : return dev_get_drvdata(&client->dev);
381 : }
382 :
383 : static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
384 : {
385 : dev_set_drvdata(&client->dev, data);
386 : }
387 :
388 : /* I2C slave support */
389 :
390 : enum i2c_slave_event {
391 : I2C_SLAVE_READ_REQUESTED,
392 : I2C_SLAVE_WRITE_REQUESTED,
393 : I2C_SLAVE_READ_PROCESSED,
394 : I2C_SLAVE_WRITE_RECEIVED,
395 : I2C_SLAVE_STOP,
396 : };
397 :
398 : int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
399 : int i2c_slave_unregister(struct i2c_client *client);
400 : int i2c_slave_event(struct i2c_client *client,
401 : enum i2c_slave_event event, u8 *val);
402 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
403 : bool i2c_detect_slave_mode(struct device *dev);
404 : #else
405 : static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
406 : #endif
407 :
408 : /**
409 : * struct i2c_board_info - template for device creation
410 : * @type: chip type, to initialize i2c_client.name
411 : * @flags: to initialize i2c_client.flags
412 : * @addr: stored in i2c_client.addr
413 : * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
414 : * @platform_data: stored in i2c_client.dev.platform_data
415 : * @of_node: pointer to OpenFirmware device node
416 : * @fwnode: device node supplied by the platform firmware
417 : * @swnode: software node for the device
418 : * @resources: resources associated with the device
419 : * @num_resources: number of resources in the @resources array
420 : * @irq: stored in i2c_client.irq
421 : *
422 : * I2C doesn't actually support hardware probing, although controllers and
423 : * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
424 : * a device at a given address. Drivers commonly need more information than
425 : * that, such as chip type, configuration, associated IRQ, and so on.
426 : *
427 : * i2c_board_info is used to build tables of information listing I2C devices
428 : * that are present. This information is used to grow the driver model tree.
429 : * For mainboards this is done statically using i2c_register_board_info();
430 : * bus numbers identify adapters that aren't yet available. For add-on boards,
431 : * i2c_new_client_device() does this dynamically with the adapter already known.
432 : */
433 : struct i2c_board_info {
434 : char type[I2C_NAME_SIZE];
435 : unsigned short flags;
436 : unsigned short addr;
437 : const char *dev_name;
438 : void *platform_data;
439 : struct device_node *of_node;
440 : struct fwnode_handle *fwnode;
441 : const struct software_node *swnode;
442 : const struct resource *resources;
443 : unsigned int num_resources;
444 : int irq;
445 : };
446 :
447 : /**
448 : * I2C_BOARD_INFO - macro used to list an i2c device and its address
449 : * @dev_type: identifies the device type
450 : * @dev_addr: the device's address on the bus.
451 : *
452 : * This macro initializes essential fields of a struct i2c_board_info,
453 : * declaring what has been provided on a particular board. Optional
454 : * fields (such as associated irq, or device-specific platform_data)
455 : * are provided using conventional syntax.
456 : */
457 : #define I2C_BOARD_INFO(dev_type, dev_addr) \
458 : .type = dev_type, .addr = (dev_addr)
459 :
460 :
461 : #if IS_ENABLED(CONFIG_I2C)
462 : /*
463 : * Add-on boards should register/unregister their devices; e.g. a board
464 : * with integrated I2C, a config eeprom, sensors, and a codec that's
465 : * used in conjunction with the primary hardware.
466 : */
467 : struct i2c_client *
468 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
469 :
470 : /* If you don't know the exact address of an I2C device, use this variant
471 : * instead, which can probe for device presence in a list of possible
472 : * addresses. The "probe" callback function is optional. If it is provided,
473 : * it must return 1 on successful probe, 0 otherwise. If it is not provided,
474 : * a default probing method is used.
475 : */
476 : struct i2c_client *
477 : i2c_new_scanned_device(struct i2c_adapter *adap,
478 : struct i2c_board_info *info,
479 : unsigned short const *addr_list,
480 : int (*probe)(struct i2c_adapter *adap, unsigned short addr));
481 :
482 : /* Common custom probe functions */
483 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
484 :
485 : struct i2c_client *
486 : i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
487 :
488 : struct i2c_client *
489 : devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
490 :
491 : struct i2c_client *
492 : i2c_new_ancillary_device(struct i2c_client *client,
493 : const char *name,
494 : u16 default_addr);
495 :
496 : void i2c_unregister_device(struct i2c_client *client);
497 :
498 : struct i2c_client *i2c_verify_client(struct device *dev);
499 : #else
500 : static inline struct i2c_client *i2c_verify_client(struct device *dev)
501 : {
502 : return NULL;
503 : }
504 : #endif /* I2C */
505 :
506 : /* Mainboard arch_initcall() code should register all its I2C devices.
507 : * This is done at arch_initcall time, before declaring any i2c adapters.
508 : * Modules for add-on boards must use other calls.
509 : */
510 : #ifdef CONFIG_I2C_BOARDINFO
511 : int
512 : i2c_register_board_info(int busnum, struct i2c_board_info const *info,
513 : unsigned n);
514 : #else
515 : static inline int
516 : i2c_register_board_info(int busnum, struct i2c_board_info const *info,
517 : unsigned n)
518 : {
519 : return 0;
520 : }
521 : #endif /* I2C_BOARDINFO */
522 :
523 : /**
524 : * struct i2c_algorithm - represent I2C transfer method
525 : * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
526 : * defined by the msgs array, with num messages available to transfer via
527 : * the adapter specified by adap.
528 : * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
529 : * so e.g. PMICs can be accessed very late before shutdown. Optional.
530 : * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
531 : * is not present, then the bus layer will try and convert the SMBus calls
532 : * into I2C transfers instead.
533 : * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
534 : * so e.g. PMICs can be accessed very late before shutdown. Optional.
535 : * @functionality: Return the flags that this algorithm/adapter pair supports
536 : * from the ``I2C_FUNC_*`` flags.
537 : * @reg_slave: Register given client to I2C slave mode of this adapter
538 : * @unreg_slave: Unregister given client from I2C slave mode of this adapter
539 : *
540 : * The following structs are for those who like to implement new bus drivers:
541 : * i2c_algorithm is the interface to a class of hardware solutions which can
542 : * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
543 : * to name two of the most common.
544 : *
545 : * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
546 : * type of error code that occurred during the transfer, as documented in the
547 : * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
548 : * number of messages executed should be returned.
549 : */
550 : struct i2c_algorithm {
551 : /*
552 : * If an adapter algorithm can't do I2C-level access, set master_xfer
553 : * to NULL. If an adapter algorithm can do SMBus access, set
554 : * smbus_xfer. If set to NULL, the SMBus protocol is simulated
555 : * using common I2C messages.
556 : *
557 : * master_xfer should return the number of messages successfully
558 : * processed, or a negative value on error
559 : */
560 : int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
561 : int num);
562 : int (*master_xfer_atomic)(struct i2c_adapter *adap,
563 : struct i2c_msg *msgs, int num);
564 : int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
565 : unsigned short flags, char read_write,
566 : u8 command, int size, union i2c_smbus_data *data);
567 : int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
568 : unsigned short flags, char read_write,
569 : u8 command, int size, union i2c_smbus_data *data);
570 :
571 : /* To determine what the adapter supports */
572 : u32 (*functionality)(struct i2c_adapter *adap);
573 :
574 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
575 : int (*reg_slave)(struct i2c_client *client);
576 : int (*unreg_slave)(struct i2c_client *client);
577 : #endif
578 : };
579 :
580 : /**
581 : * struct i2c_lock_operations - represent I2C locking operations
582 : * @lock_bus: Get exclusive access to an I2C bus segment
583 : * @trylock_bus: Try to get exclusive access to an I2C bus segment
584 : * @unlock_bus: Release exclusive access to an I2C bus segment
585 : *
586 : * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
587 : */
588 : struct i2c_lock_operations {
589 : void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
590 : int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
591 : void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
592 : };
593 :
594 : /**
595 : * struct i2c_timings - I2C timing information
596 : * @bus_freq_hz: the bus frequency in Hz
597 : * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
598 : * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
599 : * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
600 : * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
601 : * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
602 : * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
603 : * digital filter can filter out
604 : * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
605 : * analog filter
606 : */
607 : struct i2c_timings {
608 : u32 bus_freq_hz;
609 : u32 scl_rise_ns;
610 : u32 scl_fall_ns;
611 : u32 scl_int_delay_ns;
612 : u32 sda_fall_ns;
613 : u32 sda_hold_ns;
614 : u32 digital_filter_width_ns;
615 : u32 analog_filter_cutoff_freq_hz;
616 : };
617 :
618 : /**
619 : * struct i2c_bus_recovery_info - I2C bus recovery information
620 : * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
621 : * i2c_generic_scl_recovery().
622 : * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
623 : * recovery. Populated internally for generic GPIO recovery.
624 : * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
625 : * Populated internally for generic GPIO recovery.
626 : * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
627 : * for generic SCL recovery. Populated internally, if sda_gpio is a valid
628 : * GPIO, for generic GPIO recovery.
629 : * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
630 : * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
631 : * for generic GPIO recovery.
632 : * @get_bus_free: Returns the bus free state as seen from the IP core in case it
633 : * has a more complex internal logic than just reading SDA. Optional.
634 : * @prepare_recovery: This will be called before starting recovery. Platform may
635 : * configure padmux here for SDA/SCL line or something else they want.
636 : * @unprepare_recovery: This will be called after completing recovery. Platform
637 : * may configure padmux here for SDA/SCL line or something else they want.
638 : * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
639 : * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
640 : * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
641 : * Optional.
642 : * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
643 : * to the I2C bus. Optional. Populated internally for GPIO recovery, if
644 : * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
645 : * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
646 : * GPIOs. Optional. Populated internally for GPIO recovery, if this state
647 : * is called "gpio" or "recovery" and pinctrl is valid.
648 : */
649 : struct i2c_bus_recovery_info {
650 : int (*recover_bus)(struct i2c_adapter *adap);
651 :
652 : int (*get_scl)(struct i2c_adapter *adap);
653 : void (*set_scl)(struct i2c_adapter *adap, int val);
654 : int (*get_sda)(struct i2c_adapter *adap);
655 : void (*set_sda)(struct i2c_adapter *adap, int val);
656 : int (*get_bus_free)(struct i2c_adapter *adap);
657 :
658 : void (*prepare_recovery)(struct i2c_adapter *adap);
659 : void (*unprepare_recovery)(struct i2c_adapter *adap);
660 :
661 : /* gpio recovery */
662 : struct gpio_desc *scl_gpiod;
663 : struct gpio_desc *sda_gpiod;
664 : struct pinctrl *pinctrl;
665 : struct pinctrl_state *pins_default;
666 : struct pinctrl_state *pins_gpio;
667 : };
668 :
669 : int i2c_recover_bus(struct i2c_adapter *adap);
670 :
671 : /* Generic recovery routines */
672 : int i2c_generic_scl_recovery(struct i2c_adapter *adap);
673 :
674 : /**
675 : * struct i2c_adapter_quirks - describe flaws of an i2c adapter
676 : * @flags: see I2C_AQ_* for possible flags and read below
677 : * @max_num_msgs: maximum number of messages per transfer
678 : * @max_write_len: maximum length of a write message
679 : * @max_read_len: maximum length of a read message
680 : * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
681 : * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
682 : *
683 : * Note about combined messages: Some I2C controllers can only send one message
684 : * per transfer, plus something called combined message or write-then-read.
685 : * This is (usually) a small write message followed by a read message and
686 : * barely enough to access register based devices like EEPROMs. There is a flag
687 : * to support this mode. It implies max_num_msg = 2 and does the length checks
688 : * with max_comb_*_len because combined message mode usually has its own
689 : * limitations. Because of HW implementations, some controllers can actually do
690 : * write-then-anything or other variants. To support that, write-then-read has
691 : * been broken out into smaller bits like write-first and read-second which can
692 : * be combined as needed.
693 : */
694 :
695 : struct i2c_adapter_quirks {
696 : u64 flags;
697 : int max_num_msgs;
698 : u16 max_write_len;
699 : u16 max_read_len;
700 : u16 max_comb_1st_msg_len;
701 : u16 max_comb_2nd_msg_len;
702 : };
703 :
704 : /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
705 : #define I2C_AQ_COMB BIT(0)
706 : /* first combined message must be write */
707 : #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
708 : /* second combined message must be read */
709 : #define I2C_AQ_COMB_READ_SECOND BIT(2)
710 : /* both combined messages must have the same target address */
711 : #define I2C_AQ_COMB_SAME_ADDR BIT(3)
712 : /* convenience macro for typical write-then read case */
713 : #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
714 : I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
715 : /* clock stretching is not supported */
716 : #define I2C_AQ_NO_CLK_STRETCH BIT(4)
717 : /* message cannot have length of 0 */
718 : #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
719 : #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
720 : #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
721 : /* adapter cannot do repeated START */
722 : #define I2C_AQ_NO_REP_START BIT(7)
723 :
724 : /*
725 : * i2c_adapter is the structure used to identify a physical i2c bus along
726 : * with the access algorithms necessary to access it.
727 : */
728 : struct i2c_adapter {
729 : struct module *owner;
730 : unsigned int class; /* classes to allow probing for */
731 : const struct i2c_algorithm *algo; /* the algorithm to access the bus */
732 : void *algo_data;
733 :
734 : /* data fields that are valid for all devices */
735 : const struct i2c_lock_operations *lock_ops;
736 : struct rt_mutex bus_lock;
737 : struct rt_mutex mux_lock;
738 :
739 : int timeout; /* in jiffies */
740 : int retries;
741 : struct device dev; /* the adapter device */
742 : unsigned long locked_flags; /* owned by the I2C core */
743 : #define I2C_ALF_IS_SUSPENDED 0
744 : #define I2C_ALF_SUSPEND_REPORTED 1
745 :
746 : int nr;
747 : char name[48];
748 : struct completion dev_released;
749 :
750 : struct mutex userspace_clients_lock;
751 : struct list_head userspace_clients;
752 :
753 : struct i2c_bus_recovery_info *bus_recovery_info;
754 : const struct i2c_adapter_quirks *quirks;
755 :
756 : struct irq_domain *host_notify_domain;
757 : struct regulator *bus_regulator;
758 : };
759 : #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
760 :
761 : static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
762 : {
763 : return dev_get_drvdata(&adap->dev);
764 : }
765 :
766 : static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
767 : {
768 : dev_set_drvdata(&adap->dev, data);
769 : }
770 :
771 : static inline struct i2c_adapter *
772 : i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
773 : {
774 : #if IS_ENABLED(CONFIG_I2C_MUX)
775 : struct device *parent = adapter->dev.parent;
776 :
777 : if (parent != NULL && parent->type == &i2c_adapter_type)
778 : return to_i2c_adapter(parent);
779 : else
780 : #endif
781 : return NULL;
782 : }
783 :
784 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
785 :
786 : /* Adapter locking functions, exported for shared pin cases */
787 : #define I2C_LOCK_ROOT_ADAPTER BIT(0)
788 : #define I2C_LOCK_SEGMENT BIT(1)
789 :
790 : /**
791 : * i2c_lock_bus - Get exclusive access to an I2C bus segment
792 : * @adapter: Target I2C bus segment
793 : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
794 : * locks only this branch in the adapter tree
795 : */
796 : static inline void
797 : i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
798 : {
799 0 : adapter->lock_ops->lock_bus(adapter, flags);
800 : }
801 :
802 : /**
803 : * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
804 : * @adapter: Target I2C bus segment
805 : * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
806 : * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
807 : *
808 : * Return: true if the I2C bus segment is locked, false otherwise
809 : */
810 : static inline int
811 : i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
812 : {
813 0 : return adapter->lock_ops->trylock_bus(adapter, flags);
814 : }
815 :
816 : /**
817 : * i2c_unlock_bus - Release exclusive access to an I2C bus segment
818 : * @adapter: Target I2C bus segment
819 : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
820 : * unlocks only this branch in the adapter tree
821 : */
822 : static inline void
823 : i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
824 : {
825 0 : adapter->lock_ops->unlock_bus(adapter, flags);
826 : }
827 :
828 : /**
829 : * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
830 : * @adap: Adapter to mark as suspended
831 : *
832 : * When using this helper to mark an adapter as suspended, the core will reject
833 : * further transfers to this adapter. The usage of this helper is optional but
834 : * recommended for devices having distinct handlers for system suspend and
835 : * runtime suspend. More complex devices are free to implement custom solutions
836 : * to reject transfers when suspended.
837 : */
838 : static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
839 : {
840 : i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
841 : set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
842 : i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
843 : }
844 :
845 : /**
846 : * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
847 : * @adap: Adapter to mark as resumed
848 : *
849 : * When using this helper to mark an adapter as resumed, the core will allow
850 : * further transfers to this adapter. See also further notes to
851 : * @i2c_mark_adapter_suspended().
852 : */
853 : static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
854 : {
855 : i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
856 : clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
857 : i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
858 : }
859 :
860 : /* i2c adapter classes (bitmask) */
861 : #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
862 : #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
863 : #define I2C_CLASS_SPD (1<<7) /* Memory modules */
864 : /* Warn users that the adapter doesn't support classes anymore */
865 : #define I2C_CLASS_DEPRECATED (1<<8)
866 :
867 : /* Internal numbers to terminate lists */
868 : #define I2C_CLIENT_END 0xfffeU
869 :
870 : /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
871 : #define I2C_ADDRS(addr, addrs...) \
872 : ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
873 :
874 :
875 : /* ----- functions exported by i2c.o */
876 :
877 : /* administration...
878 : */
879 : #if IS_ENABLED(CONFIG_I2C)
880 : int i2c_add_adapter(struct i2c_adapter *adap);
881 : int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
882 : void i2c_del_adapter(struct i2c_adapter *adap);
883 : int i2c_add_numbered_adapter(struct i2c_adapter *adap);
884 :
885 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
886 : void i2c_del_driver(struct i2c_driver *driver);
887 :
888 : /* use a define to avoid include chaining to get THIS_MODULE */
889 : #define i2c_add_driver(driver) \
890 : i2c_register_driver(THIS_MODULE, driver)
891 :
892 : static inline bool i2c_client_has_driver(struct i2c_client *client)
893 : {
894 0 : return !IS_ERR_OR_NULL(client) && client->dev.driver;
895 : }
896 :
897 : /* call the i2c_client->command() of all attached clients with
898 : * the given arguments */
899 : void i2c_clients_command(struct i2c_adapter *adap,
900 : unsigned int cmd, void *arg);
901 :
902 : struct i2c_adapter *i2c_get_adapter(int nr);
903 : void i2c_put_adapter(struct i2c_adapter *adap);
904 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
905 :
906 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
907 :
908 : /* Return the functionality mask */
909 : static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
910 : {
911 0 : return adap->algo->functionality(adap);
912 : }
913 :
914 : /* Return 1 if adapter supports everything we need, 0 if not. */
915 : static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
916 : {
917 0 : return (func & i2c_get_functionality(adap)) == func;
918 : }
919 :
920 : /**
921 : * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
922 : * @adap: i2c adapter
923 : * @quirks: quirk flags
924 : *
925 : * Return: true if the adapter has all the specified quirk flags, false if not
926 : */
927 : static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
928 : {
929 : if (!adap->quirks)
930 : return false;
931 : return (adap->quirks->flags & quirks) == quirks;
932 : }
933 :
934 : /* Return the adapter number for a specific adapter */
935 : static inline int i2c_adapter_id(struct i2c_adapter *adap)
936 : {
937 : return adap->nr;
938 : }
939 :
940 : static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
941 : {
942 0 : return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
943 : }
944 :
945 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
946 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
947 :
948 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
949 : /**
950 : * module_i2c_driver() - Helper macro for registering a modular I2C driver
951 : * @__i2c_driver: i2c_driver struct
952 : *
953 : * Helper macro for I2C drivers which do not do anything special in module
954 : * init/exit. This eliminates a lot of boilerplate. Each module may only
955 : * use this macro once, and calling it replaces module_init() and module_exit()
956 : */
957 : #define module_i2c_driver(__i2c_driver) \
958 : module_driver(__i2c_driver, i2c_add_driver, \
959 : i2c_del_driver)
960 :
961 : /**
962 : * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
963 : * @__i2c_driver: i2c_driver struct
964 : *
965 : * Helper macro for I2C drivers which do not do anything special in their
966 : * init. This eliminates a lot of boilerplate. Each driver may only
967 : * use this macro once, and calling it replaces device_initcall().
968 : */
969 : #define builtin_i2c_driver(__i2c_driver) \
970 : builtin_driver(__i2c_driver, i2c_add_driver)
971 :
972 : #endif /* I2C */
973 :
974 : /* must call put_device() when done with returned i2c_client device */
975 : struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode);
976 :
977 : /* must call put_device() when done with returned i2c_adapter device */
978 : struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode);
979 :
980 : /* must call i2c_put_adapter() when done with returned i2c_adapter device */
981 : struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode);
982 :
983 : #if IS_ENABLED(CONFIG_OF)
984 : /* must call put_device() when done with returned i2c_client device */
985 : static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
986 : {
987 : return i2c_find_device_by_fwnode(of_fwnode_handle(node));
988 : }
989 :
990 : /* must call put_device() when done with returned i2c_adapter device */
991 : static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
992 : {
993 : return i2c_find_adapter_by_fwnode(of_fwnode_handle(node));
994 : }
995 :
996 : /* must call i2c_put_adapter() when done with returned i2c_adapter device */
997 : static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
998 : {
999 : return i2c_get_adapter_by_fwnode(of_fwnode_handle(node));
1000 : }
1001 :
1002 : const struct of_device_id
1003 : *i2c_of_match_device(const struct of_device_id *matches,
1004 : struct i2c_client *client);
1005 :
1006 : int of_i2c_get_board_info(struct device *dev, struct device_node *node,
1007 : struct i2c_board_info *info);
1008 :
1009 : #else
1010 :
1011 : static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1012 : {
1013 : return NULL;
1014 : }
1015 :
1016 : static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1017 : {
1018 : return NULL;
1019 : }
1020 :
1021 : static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1022 : {
1023 : return NULL;
1024 : }
1025 :
1026 : static inline const struct of_device_id
1027 : *i2c_of_match_device(const struct of_device_id *matches,
1028 : struct i2c_client *client)
1029 : {
1030 : return NULL;
1031 : }
1032 :
1033 : static inline int of_i2c_get_board_info(struct device *dev,
1034 : struct device_node *node,
1035 : struct i2c_board_info *info)
1036 : {
1037 : return -ENOTSUPP;
1038 : }
1039 :
1040 : #endif /* CONFIG_OF */
1041 :
1042 : struct acpi_resource;
1043 : struct acpi_resource_i2c_serialbus;
1044 :
1045 : #if IS_ENABLED(CONFIG_ACPI)
1046 : bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1047 : struct acpi_resource_i2c_serialbus **i2c);
1048 : int i2c_acpi_client_count(struct acpi_device *adev);
1049 : u32 i2c_acpi_find_bus_speed(struct device *dev);
1050 : struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1051 : int index,
1052 : struct i2c_board_info *info);
1053 : struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1054 : bool i2c_acpi_waive_d0_probe(struct device *dev);
1055 : #else
1056 : static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1057 : struct acpi_resource_i2c_serialbus **i2c)
1058 : {
1059 : return false;
1060 : }
1061 : static inline int i2c_acpi_client_count(struct acpi_device *adev)
1062 : {
1063 : return 0;
1064 : }
1065 : static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1066 : {
1067 : return 0;
1068 : }
1069 : static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1070 : struct fwnode_handle *fwnode, int index,
1071 : struct i2c_board_info *info)
1072 : {
1073 : return ERR_PTR(-ENODEV);
1074 : }
1075 : static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1076 : {
1077 : return NULL;
1078 : }
1079 : static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1080 : {
1081 : return false;
1082 : }
1083 : #endif /* CONFIG_ACPI */
1084 :
1085 : static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1086 : int index,
1087 : struct i2c_board_info *info)
1088 : {
1089 : return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1090 : }
1091 :
1092 : #endif /* _LINUX_I2C_H */
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