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