xref: /linux/include/linux/i2c.h (revision 77b679453d3364688ff3e5153c0be5b2b52672b7)
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 const struct bus_type i2c_bus_type;
27 extern const struct device_type i2c_adapter_type;
28 extern const struct device_type i2c_client_type;
29 
30 /* --- General options ------------------------------------------------	*/
31 
32 struct i2c_msg;
33 struct i2c_adapter;
34 struct i2c_client;
35 struct i2c_driver;
36 struct i2c_device_identity;
37 union i2c_smbus_data;
38 struct i2c_board_info;
39 enum i2c_slave_event;
40 typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
41 			      enum i2c_slave_event event, u8 *val);
42 
43 /* I2C Frequency Modes */
44 #define I2C_MAX_STANDARD_MODE_FREQ	100000
45 #define I2C_MAX_FAST_MODE_FREQ		400000
46 #define I2C_MAX_FAST_MODE_PLUS_FREQ	1000000
47 #define I2C_MAX_TURBO_MODE_FREQ		1400000
48 #define I2C_MAX_HIGH_SPEED_MODE_FREQ	3400000
49 #define I2C_MAX_ULTRA_FAST_MODE_FREQ	5000000
50 
51 struct module;
52 struct property_entry;
53 
54 #if IS_ENABLED(CONFIG_I2C)
55 /* Return the Frequency mode string based on the bus frequency */
56 const char *i2c_freq_mode_string(u32 bus_freq_hz);
57 
58 /*
59  * The master routines are the ones normally used to transmit data to devices
60  * on a bus (or read from them). Apart from two basic transfer functions to
61  * transmit one message at a time, a more complex version can be used to
62  * transmit an arbitrary number of messages without interruption.
63  * @count must be less than 64k since msg.len is u16.
64  */
65 int i2c_transfer_buffer_flags(const struct i2c_client *client,
66 			      char *buf, int count, u16 flags);
67 
68 /**
69  * i2c_master_recv - issue a single I2C message in master receive mode
70  * @client: Handle to slave device
71  * @buf: Where to store data read from slave
72  * @count: How many bytes to read, must be less than 64k since msg.len is u16
73  *
74  * Returns negative errno, or else the number of bytes read.
75  */
i2c_master_recv(const struct i2c_client * client,char * buf,int count)76 static inline int i2c_master_recv(const struct i2c_client *client,
77 				  char *buf, int count)
78 {
79 	return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
80 };
81 
82 /**
83  * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
84  *			     using a DMA safe buffer
85  * @client: Handle to slave device
86  * @buf: Where to store data read from slave, must be safe to use with DMA
87  * @count: How many bytes to read, must be less than 64k since msg.len is u16
88  *
89  * Returns negative errno, or else the number of bytes read.
90  */
i2c_master_recv_dmasafe(const struct i2c_client * client,char * buf,int count)91 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
92 					  char *buf, int count)
93 {
94 	return i2c_transfer_buffer_flags(client, buf, count,
95 					 I2C_M_RD | I2C_M_DMA_SAFE);
96 };
97 
98 /**
99  * i2c_master_send - issue a single I2C message in master transmit mode
100  * @client: Handle to slave device
101  * @buf: Data that will be written to the slave
102  * @count: How many bytes to write, must be less than 64k since msg.len is u16
103  *
104  * Returns negative errno, or else the number of bytes written.
105  */
i2c_master_send(const struct i2c_client * client,const char * buf,int count)106 static inline int i2c_master_send(const struct i2c_client *client,
107 				  const char *buf, int count)
108 {
109 	return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
110 };
111 
112 /**
113  * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
114  *			     using a DMA safe buffer
115  * @client: Handle to slave device
116  * @buf: Data that will be written to the slave, must be safe to use with DMA
117  * @count: How many bytes to write, must be less than 64k since msg.len is u16
118  *
119  * Returns negative errno, or else the number of bytes written.
120  */
i2c_master_send_dmasafe(const struct i2c_client * client,const char * buf,int count)121 static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
122 					  const char *buf, int count)
123 {
124 	return i2c_transfer_buffer_flags(client, (char *)buf, count,
125 					 I2C_M_DMA_SAFE);
126 };
127 
128 /* Transfer num messages.
129  */
130 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
131 /* Unlocked flavor */
132 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
133 
134 /* This is the very generalized SMBus access routine. You probably do not
135    want to use this, though; one of the functions below may be much easier,
136    and probably just as fast.
137    Note that we use i2c_adapter here, because you do not need a specific
138    smbus adapter to call this function. */
139 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
140 		   unsigned short flags, char read_write, u8 command,
141 		   int protocol, union i2c_smbus_data *data);
142 
143 /* Unlocked flavor */
144 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
145 		     unsigned short flags, char read_write, u8 command,
146 		     int protocol, union i2c_smbus_data *data);
147 
148 /* Now follow the 'nice' access routines. These also document the calling
149    conventions of i2c_smbus_xfer. */
150 
151 u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
152 s32 i2c_smbus_read_byte(const struct i2c_client *client);
153 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
154 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
155 s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
156 			      u8 command, u8 value);
157 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
158 s32 i2c_smbus_write_word_data(const struct i2c_client *client,
159 			      u8 command, u16 value);
160 
161 static inline s32
i2c_smbus_read_word_swapped(const struct i2c_client * client,u8 command)162 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
163 {
164 	s32 value = i2c_smbus_read_word_data(client, command);
165 
166 	return (value < 0) ? value : swab16(value);
167 }
168 
169 static inline s32
i2c_smbus_write_word_swapped(const struct i2c_client * client,u8 command,u16 value)170 i2c_smbus_write_word_swapped(const struct i2c_client *client,
171 			     u8 command, u16 value)
172 {
173 	return i2c_smbus_write_word_data(client, command, swab16(value));
174 }
175 
176 /* Returns the number of read bytes */
177 s32 i2c_smbus_read_block_data(const struct i2c_client *client,
178 			      u8 command, u8 *values);
179 s32 i2c_smbus_write_block_data(const struct i2c_client *client,
180 			       u8 command, u8 length, const u8 *values);
181 /* Returns the number of read bytes */
182 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
183 				  u8 command, u8 length, u8 *values);
184 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
185 				   u8 command, u8 length, const u8 *values);
186 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
187 					      u8 command, u8 length,
188 					      u8 *values);
189 int i2c_get_device_id(const struct i2c_client *client,
190 		      struct i2c_device_identity *id);
191 const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client);
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
239  * @remove: Callback for device unbinding
240  * @shutdown: Callback for device shutdown
241  * @alert: Alert callback, for example for the SMBus alert protocol
242  * @command: Callback for bus-wide signaling (optional)
243  * @driver: Device driver model driver
244  * @id_table: List of I2C devices supported by this driver
245  * @detect: Callback for device detection
246  * @address_list: The I2C addresses to probe (for detect)
247  * @clients: List of detected clients we created (for i2c-core use only)
248  * @flags: A bitmask of flags defined in &enum i2c_driver_flags
249  *
250  * The driver.owner field should be set to the module owner of this driver.
251  * The driver.name field should be set to the name of this driver.
252  *
253  * For automatic device detection, both @detect and @address_list must
254  * be defined. @class should also be set, otherwise only devices forced
255  * with module parameters will be created. The detect function must
256  * fill at least the name field of the i2c_board_info structure it is
257  * handed upon successful detection, and possibly also the flags field.
258  *
259  * If @detect is missing, the driver will still work fine for enumerated
260  * devices. Detected devices simply won't be supported. This is expected
261  * for the many I2C/SMBus devices which can't be detected reliably, and
262  * the ones which can always be enumerated in practice.
263  *
264  * The i2c_client structure which is handed to the @detect callback is
265  * not a real i2c_client. It is initialized just enough so that you can
266  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
267  * else with it. In particular, calling dev_dbg and friends on it is
268  * not allowed.
269  */
270 struct i2c_driver {
271 	unsigned int class;
272 
273 	/* Standard driver model interfaces */
274 	int (*probe)(struct i2c_client *client);
275 	void (*remove)(struct i2c_client *client);
276 
277 
278 	/* driver model interfaces that don't relate to enumeration  */
279 	void (*shutdown)(struct i2c_client *client);
280 
281 	/* Alert callback, for example for the SMBus alert protocol.
282 	 * The format and meaning of the data value depends on the protocol.
283 	 * For the SMBus alert protocol, there is a single bit of data passed
284 	 * as the alert response's low bit ("event flag").
285 	 * For the SMBus Host Notify protocol, the data corresponds to the
286 	 * 16-bit payload data reported by the slave device acting as master.
287 	 */
288 	void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
289 		      unsigned int data);
290 
291 	/* a ioctl like command that can be used to perform specific functions
292 	 * with the device.
293 	 */
294 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
295 
296 	struct device_driver driver;
297 	const struct i2c_device_id *id_table;
298 
299 	/* Device detection callback for automatic device creation */
300 	int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
301 	const unsigned short *address_list;
302 	struct list_head clients;
303 
304 	u32 flags;
305 };
306 #define to_i2c_driver(d) container_of_const(d, struct i2c_driver, driver)
307 
308 /**
309  * struct i2c_client - represent an I2C slave device
310  * @flags: see I2C_CLIENT_* for possible flags
311  * @addr: Address used on the I2C bus connected to the parent adapter.
312  * @name: Indicates the type of the device, usually a chip name that's
313  *	generic enough to hide second-sourcing and compatible revisions.
314  * @adapter: manages the bus segment hosting this I2C device
315  * @dev: Driver model device node for the slave.
316  * @init_irq: IRQ that was set at initialization
317  * @irq: indicates the IRQ generated by this device (if any)
318  * @detected: member of an i2c_driver.clients list or i2c-core's
319  *	userspace_devices list
320  * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
321  *	calls it to pass on slave events to the slave driver.
322  * @devres_group_id: id of the devres group that will be created for resources
323  *	acquired when probing this device.
324  *
325  * An i2c_client identifies a single device (i.e. chip) connected to an
326  * i2c bus. The behaviour exposed to Linux is defined by the driver
327  * managing the device.
328  */
329 struct i2c_client {
330 	unsigned short flags;		/* div., see below		*/
331 #define I2C_CLIENT_PEC		0x04	/* Use Packet Error Checking */
332 #define I2C_CLIENT_TEN		0x10	/* we have a ten bit chip address */
333 					/* Must equal I2C_M_TEN below */
334 #define I2C_CLIENT_SLAVE	0x20	/* we are the slave */
335 #define I2C_CLIENT_HOST_NOTIFY	0x40	/* We want to use I2C host notify */
336 #define I2C_CLIENT_WAKE		0x80	/* for board_info; true iff can wake */
337 #define I2C_CLIENT_SCCB		0x9000	/* Use Omnivision SCCB protocol */
338 					/* Must match I2C_M_STOP|IGNORE_NAK */
339 
340 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
341 					/* addresses are stored in the	*/
342 					/* _LOWER_ 7 bits		*/
343 	char name[I2C_NAME_SIZE];
344 	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
345 	struct device dev;		/* the device structure		*/
346 	int init_irq;			/* irq set at initialization	*/
347 	int irq;			/* irq issued by device		*/
348 	struct list_head detected;
349 #if IS_ENABLED(CONFIG_I2C_SLAVE)
350 	i2c_slave_cb_t slave_cb;	/* callback for slave mode	*/
351 #endif
352 	void *devres_group_id;		/* ID of probe devres group	*/
353 };
354 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
355 
356 struct i2c_adapter *i2c_verify_adapter(struct device *dev);
357 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
358 					 const struct i2c_client *client);
359 
360 const void *i2c_get_match_data(const struct i2c_client *client);
361 
kobj_to_i2c_client(struct kobject * kobj)362 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
363 {
364 	struct device * const dev = kobj_to_dev(kobj);
365 	return to_i2c_client(dev);
366 }
367 
i2c_get_clientdata(const struct i2c_client * client)368 static inline void *i2c_get_clientdata(const struct i2c_client *client)
369 {
370 	return dev_get_drvdata(&client->dev);
371 }
372 
i2c_set_clientdata(struct i2c_client * client,void * data)373 static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
374 {
375 	dev_set_drvdata(&client->dev, data);
376 }
377 
378 /* I2C slave support */
379 
380 enum i2c_slave_event {
381 	I2C_SLAVE_READ_REQUESTED,
382 	I2C_SLAVE_WRITE_REQUESTED,
383 	I2C_SLAVE_READ_PROCESSED,
384 	I2C_SLAVE_WRITE_RECEIVED,
385 	I2C_SLAVE_STOP,
386 };
387 
388 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
389 int i2c_slave_unregister(struct i2c_client *client);
390 int i2c_slave_event(struct i2c_client *client,
391 		    enum i2c_slave_event event, u8 *val);
392 #if IS_ENABLED(CONFIG_I2C_SLAVE)
393 bool i2c_detect_slave_mode(struct device *dev);
394 #else
i2c_detect_slave_mode(struct device * dev)395 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
396 #endif
397 
398 /**
399  * struct i2c_board_info - template for device creation
400  * @type: chip type, to initialize i2c_client.name
401  * @flags: to initialize i2c_client.flags
402  * @addr: stored in i2c_client.addr
403  * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
404  * @platform_data: stored in i2c_client.dev.platform_data
405  * @of_node: pointer to OpenFirmware device node
406  * @fwnode: device node supplied by the platform firmware
407  * @swnode: software node for the device
408  * @resources: resources associated with the device
409  * @num_resources: number of resources in the @resources array
410  * @irq: stored in i2c_client.irq
411  *
412  * I2C doesn't actually support hardware probing, although controllers and
413  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
414  * a device at a given address.  Drivers commonly need more information than
415  * that, such as chip type, configuration, associated IRQ, and so on.
416  *
417  * i2c_board_info is used to build tables of information listing I2C devices
418  * that are present.  This information is used to grow the driver model tree.
419  * For mainboards this is done statically using i2c_register_board_info();
420  * bus numbers identify adapters that aren't yet available.  For add-on boards,
421  * i2c_new_client_device() does this dynamically with the adapter already known.
422  */
423 struct i2c_board_info {
424 	char		type[I2C_NAME_SIZE];
425 	unsigned short	flags;
426 	unsigned short	addr;
427 	const char	*dev_name;
428 	void		*platform_data;
429 	struct device_node *of_node;
430 	struct fwnode_handle *fwnode;
431 	const struct software_node *swnode;
432 	const struct resource *resources;
433 	unsigned int	num_resources;
434 	int		irq;
435 };
436 
437 /**
438  * I2C_BOARD_INFO - macro used to list an i2c device and its address
439  * @dev_type: identifies the device type
440  * @dev_addr: the device's address on the bus.
441  *
442  * This macro initializes essential fields of a struct i2c_board_info,
443  * declaring what has been provided on a particular board.  Optional
444  * fields (such as associated irq, or device-specific platform_data)
445  * are provided using conventional syntax.
446  */
447 #define I2C_BOARD_INFO(dev_type, dev_addr) \
448 	.type = dev_type, .addr = (dev_addr)
449 
450 
451 #if IS_ENABLED(CONFIG_I2C)
452 /*
453  * Add-on boards should register/unregister their devices; e.g. a board
454  * with integrated I2C, a config eeprom, sensors, and a codec that's
455  * used in conjunction with the primary hardware.
456  */
457 struct i2c_client *
458 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
459 
460 /* If you don't know the exact address of an I2C device, use this variant
461  * instead, which can probe for device presence in a list of possible
462  * addresses. The "probe" callback function is optional. If it is provided,
463  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
464  * a default probing method is used.
465  */
466 struct i2c_client *
467 i2c_new_scanned_device(struct i2c_adapter *adap,
468 		       struct i2c_board_info *info,
469 		       unsigned short const *addr_list,
470 		       int (*probe)(struct i2c_adapter *adap, unsigned short addr));
471 
472 /* Common custom probe functions */
473 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
474 
475 struct i2c_client *
476 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
477 
478 struct i2c_client *
479 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
480 
481 struct i2c_client *
482 i2c_new_ancillary_device(struct i2c_client *client,
483 			 const char *name,
484 			 u16 default_addr);
485 
486 void i2c_unregister_device(struct i2c_client *client);
487 
488 struct i2c_client *i2c_verify_client(struct device *dev);
489 #else
i2c_verify_client(struct device * dev)490 static inline struct i2c_client *i2c_verify_client(struct device *dev)
491 {
492 	return NULL;
493 }
494 #endif /* I2C */
495 
496 /* Mainboard arch_initcall() code should register all its I2C devices.
497  * This is done at arch_initcall time, before declaring any i2c adapters.
498  * Modules for add-on boards must use other calls.
499  */
500 #ifdef CONFIG_I2C_BOARDINFO
501 int
502 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
503 			unsigned n);
504 #else
505 static inline int
i2c_register_board_info(int busnum,struct i2c_board_info const * info,unsigned n)506 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
507 			unsigned n)
508 {
509 	return 0;
510 }
511 #endif /* I2C_BOARDINFO */
512 
513 /**
514  * struct i2c_algorithm - represent I2C transfer methods
515  * @xfer: Transfer a given number of messages defined by the msgs array via
516  *   the specified adapter.
517  * @xfer_atomic: Same as @xfer. Yet, only using atomic context so e.g. PMICs
518  *   can be accessed very late before shutdown. Optional.
519  * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this
520  *   is not present, then the bus layer will try and convert the SMBus calls
521  *   into I2C transfers instead.
522  * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context
523  *   so e.g. PMICs can be accessed very late before shutdown. Optional.
524  * @functionality: Return the flags that this algorithm/adapter pair supports
525  *   from the ``I2C_FUNC_*`` flags.
526  * @reg_target: Register given client to local target mode of this adapter
527  * @unreg_target: Unregister given client from local target mode of this adapter
528  *
529  * @master_xfer: deprecated, use @xfer
530  * @master_xfer_atomic: deprecated, use @xfer_atomic
531  * @reg_slave: deprecated, use @reg_target
532  * @unreg_slave: deprecated, use @unreg_target
533  *
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 ``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. Otherwise, the
541  * number of messages executed should be returned.
542  */
543 struct i2c_algorithm {
544 	/*
545 	 * If an adapter algorithm can't do I2C-level access, set xfer
546 	 * to NULL. If an adapter algorithm can do SMBus access, set
547 	 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
548 	 * using common I2C messages.
549 	 */
550 	union {
551 		int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
552 			    int num);
553 		int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
554 				   int num);
555 	};
556 	union {
557 		int (*xfer_atomic)(struct i2c_adapter *adap,
558 				   struct i2c_msg *msgs, int num);
559 		int (*master_xfer_atomic)(struct i2c_adapter *adap,
560 					   struct i2c_msg *msgs, int num);
561 	};
562 	int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
563 			  unsigned short flags, char read_write,
564 			  u8 command, int size, union i2c_smbus_data *data);
565 	int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
566 				 unsigned short flags, char read_write,
567 				 u8 command, int size, union i2c_smbus_data *data);
568 
569 	/* To determine what the adapter supports */
570 	u32 (*functionality)(struct i2c_adapter *adap);
571 
572 #if IS_ENABLED(CONFIG_I2C_SLAVE)
573 	union {
574 		int (*reg_target)(struct i2c_client *client);
575 		int (*reg_slave)(struct i2c_client *client);
576 	};
577 	union {
578 		int (*unreg_target)(struct i2c_client *client);
579 		int (*unreg_slave)(struct i2c_client *client);
580 	};
581 #endif
582 };
583 
584 /**
585  * struct i2c_lock_operations - represent I2C locking operations
586  * @lock_bus: Get exclusive access to an I2C bus segment
587  * @trylock_bus: Try to get exclusive access to an I2C bus segment
588  * @unlock_bus: Release exclusive access to an I2C bus segment
589  *
590  * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
591  */
592 struct i2c_lock_operations {
593 	void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
594 	int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
595 	void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
596 };
597 
598 /**
599  * struct i2c_timings - I2C timing information
600  * @bus_freq_hz: the bus frequency in Hz
601  * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
602  * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
603  * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
604  * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
605  * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
606  * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
607  *	digital filter can filter out
608  * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
609  *	analog filter
610  */
611 struct i2c_timings {
612 	u32 bus_freq_hz;
613 	u32 scl_rise_ns;
614 	u32 scl_fall_ns;
615 	u32 scl_int_delay_ns;
616 	u32 sda_fall_ns;
617 	u32 sda_hold_ns;
618 	u32 digital_filter_width_ns;
619 	u32 analog_filter_cutoff_freq_hz;
620 };
621 
622 /**
623  * struct i2c_bus_recovery_info - I2C bus recovery information
624  * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
625  *	i2c_generic_scl_recovery().
626  * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
627  *      recovery. Populated internally for generic GPIO recovery.
628  * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
629  *      Populated internally for generic GPIO recovery.
630  * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
631  *	for generic SCL recovery. Populated internally, if sda_gpio is a valid
632  *	GPIO, for generic GPIO recovery.
633  * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
634  *	generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
635  *	for generic GPIO recovery.
636  * @get_bus_free: Returns the bus free state as seen from the IP core in case it
637  *	has a more complex internal logic than just reading SDA. Optional.
638  * @prepare_recovery: This will be called before starting recovery. Platform may
639  *	configure padmux here for SDA/SCL line or something else they want.
640  * @unprepare_recovery: This will be called after completing recovery. Platform
641  *	may configure padmux here for SDA/SCL line or something else they want.
642  * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
643  * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
644  * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
645  *      Optional.
646  * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
647  *      to the I2C bus. Optional. Populated internally for GPIO recovery, if
648  *      state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
649  * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
650  *      GPIOs. Optional. Populated internally for GPIO recovery, if this state
651  *      is called "gpio" or "recovery" and pinctrl is valid.
652  */
653 struct i2c_bus_recovery_info {
654 	int (*recover_bus)(struct i2c_adapter *adap);
655 
656 	int (*get_scl)(struct i2c_adapter *adap);
657 	void (*set_scl)(struct i2c_adapter *adap, int val);
658 	int (*get_sda)(struct i2c_adapter *adap);
659 	void (*set_sda)(struct i2c_adapter *adap, int val);
660 	int (*get_bus_free)(struct i2c_adapter *adap);
661 
662 	void (*prepare_recovery)(struct i2c_adapter *adap);
663 	void (*unprepare_recovery)(struct i2c_adapter *adap);
664 
665 	/* gpio recovery */
666 	struct gpio_desc *scl_gpiod;
667 	struct gpio_desc *sda_gpiod;
668 	struct pinctrl *pinctrl;
669 	struct pinctrl_state *pins_default;
670 	struct pinctrl_state *pins_gpio;
671 };
672 
673 int i2c_recover_bus(struct i2c_adapter *adap);
674 
675 /* Generic recovery routines */
676 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
677 
678 /**
679  * struct i2c_adapter_quirks - describe flaws of an i2c adapter
680  * @flags: see I2C_AQ_* for possible flags and read below
681  * @max_num_msgs: maximum number of messages per transfer
682  * @max_write_len: maximum length of a write message
683  * @max_read_len: maximum length of a read message
684  * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
685  * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
686  *
687  * Note about combined messages: Some I2C controllers can only send one message
688  * per transfer, plus something called combined message or write-then-read.
689  * This is (usually) a small write message followed by a read message and
690  * barely enough to access register based devices like EEPROMs. There is a flag
691  * to support this mode. It implies max_num_msg = 2 and does the length checks
692  * with max_comb_*_len because combined message mode usually has its own
693  * limitations. Because of HW implementations, some controllers can actually do
694  * write-then-anything or other variants. To support that, write-then-read has
695  * been broken out into smaller bits like write-first and read-second which can
696  * be combined as needed.
697  */
698 
699 struct i2c_adapter_quirks {
700 	u64 flags;
701 	int max_num_msgs;
702 	u16 max_write_len;
703 	u16 max_read_len;
704 	u16 max_comb_1st_msg_len;
705 	u16 max_comb_2nd_msg_len;
706 };
707 
708 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
709 #define I2C_AQ_COMB			BIT(0)
710 /* first combined message must be write */
711 #define I2C_AQ_COMB_WRITE_FIRST		BIT(1)
712 /* second combined message must be read */
713 #define I2C_AQ_COMB_READ_SECOND		BIT(2)
714 /* both combined messages must have the same target address */
715 #define I2C_AQ_COMB_SAME_ADDR		BIT(3)
716 /* convenience macro for typical write-then read case */
717 #define I2C_AQ_COMB_WRITE_THEN_READ	(I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
718 					 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
719 /* clock stretching is not supported */
720 #define I2C_AQ_NO_CLK_STRETCH		BIT(4)
721 /* message cannot have length of 0 */
722 #define I2C_AQ_NO_ZERO_LEN_READ		BIT(5)
723 #define I2C_AQ_NO_ZERO_LEN_WRITE	BIT(6)
724 #define I2C_AQ_NO_ZERO_LEN		(I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
725 /* adapter cannot do repeated START */
726 #define I2C_AQ_NO_REP_START		BIT(7)
727 
728 /*
729  * i2c_adapter is the structure used to identify a physical i2c bus along
730  * with the access algorithms necessary to access it.
731  */
732 struct i2c_adapter {
733 	struct module *owner;
734 	unsigned int class;		  /* classes to allow probing for */
735 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
736 	void *algo_data;
737 
738 	/* data fields that are valid for all devices	*/
739 	const struct i2c_lock_operations *lock_ops;
740 	struct rt_mutex bus_lock;
741 	struct rt_mutex mux_lock;
742 
743 	int timeout;			/* in jiffies */
744 	int retries;
745 	struct device dev;		/* the adapter device */
746 	unsigned long locked_flags;	/* owned by the I2C core */
747 #define I2C_ALF_IS_SUSPENDED		0
748 #define I2C_ALF_SUSPEND_REPORTED	1
749 
750 	int nr;
751 	char name[48];
752 	struct completion dev_released;
753 
754 	struct mutex userspace_clients_lock;
755 	struct list_head userspace_clients;
756 
757 	struct i2c_bus_recovery_info *bus_recovery_info;
758 	const struct i2c_adapter_quirks *quirks;
759 
760 	struct irq_domain *host_notify_domain;
761 	struct regulator *bus_regulator;
762 
763 	struct dentry *debugfs;
764 
765 	/* 7bit address space */
766 	DECLARE_BITMAP(addrs_in_instantiation, 1 << 7);
767 };
768 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
769 
i2c_get_adapdata(const struct i2c_adapter * adap)770 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
771 {
772 	return dev_get_drvdata(&adap->dev);
773 }
774 
i2c_set_adapdata(struct i2c_adapter * adap,void * data)775 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
776 {
777 	dev_set_drvdata(&adap->dev, data);
778 }
779 
780 static inline struct i2c_adapter *
i2c_parent_is_i2c_adapter(const struct i2c_adapter * adapter)781 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
782 {
783 #if IS_ENABLED(CONFIG_I2C_MUX)
784 	struct device *parent = adapter->dev.parent;
785 
786 	if (parent != NULL && parent->type == &i2c_adapter_type)
787 		return to_i2c_adapter(parent);
788 	else
789 #endif
790 		return NULL;
791 }
792 
793 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
794 
795 /* Adapter locking functions, exported for shared pin cases */
796 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
797 #define I2C_LOCK_SEGMENT      BIT(1)
798 
799 /**
800  * i2c_lock_bus - Get exclusive access to an I2C bus segment
801  * @adapter: Target I2C bus segment
802  * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
803  *	locks only this branch in the adapter tree
804  */
805 static inline void
i2c_lock_bus(struct i2c_adapter * adapter,unsigned int flags)806 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
807 {
808 	adapter->lock_ops->lock_bus(adapter, flags);
809 }
810 
811 /**
812  * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
813  * @adapter: Target I2C bus segment
814  * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
815  *	I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
816  *
817  * Return: true if the I2C bus segment is locked, false otherwise
818  */
819 static inline int
i2c_trylock_bus(struct i2c_adapter * adapter,unsigned int flags)820 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
821 {
822 	return adapter->lock_ops->trylock_bus(adapter, flags);
823 }
824 
825 /**
826  * i2c_unlock_bus - Release exclusive access to an I2C bus segment
827  * @adapter: Target I2C bus segment
828  * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
829  *	unlocks only this branch in the adapter tree
830  */
831 static inline void
i2c_unlock_bus(struct i2c_adapter * adapter,unsigned int flags)832 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
833 {
834 	adapter->lock_ops->unlock_bus(adapter, flags);
835 }
836 
837 /**
838  * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
839  * @adap: Adapter to mark as suspended
840  *
841  * When using this helper to mark an adapter as suspended, the core will reject
842  * further transfers to this adapter. The usage of this helper is optional but
843  * recommended for devices having distinct handlers for system suspend and
844  * runtime suspend. More complex devices are free to implement custom solutions
845  * to reject transfers when suspended.
846  */
i2c_mark_adapter_suspended(struct i2c_adapter * adap)847 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
848 {
849 	i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
850 	set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
851 	i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
852 }
853 
854 /**
855  * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
856  * @adap: Adapter to mark as resumed
857  *
858  * When using this helper to mark an adapter as resumed, the core will allow
859  * further transfers to this adapter. See also further notes to
860  * @i2c_mark_adapter_suspended().
861  */
i2c_mark_adapter_resumed(struct i2c_adapter * adap)862 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
863 {
864 	i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
865 	clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
866 	i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
867 }
868 
869 /* i2c adapter classes (bitmask) */
870 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
871 /* Warn users that the adapter doesn't support classes anymore */
872 #define I2C_CLASS_DEPRECATED	(1<<8)
873 
874 /* Internal numbers to terminate lists */
875 #define I2C_CLIENT_END		0xfffeU
876 
877 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
878 #define I2C_ADDRS(addr, addrs...) \
879 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
880 
881 
882 /* ----- functions exported by i2c.o */
883 
884 /* administration...
885  */
886 #if IS_ENABLED(CONFIG_I2C)
887 int i2c_add_adapter(struct i2c_adapter *adap);
888 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
889 void i2c_del_adapter(struct i2c_adapter *adap);
890 int i2c_add_numbered_adapter(struct i2c_adapter *adap);
891 
892 int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
893 void i2c_del_driver(struct i2c_driver *driver);
894 
895 /* use a define to avoid include chaining to get THIS_MODULE */
896 #define i2c_add_driver(driver) \
897 	i2c_register_driver(THIS_MODULE, driver)
898 
i2c_client_has_driver(struct i2c_client * client)899 static inline bool i2c_client_has_driver(struct i2c_client *client)
900 {
901 	return !IS_ERR_OR_NULL(client) && client->dev.driver;
902 }
903 
904 /* call the i2c_client->command() of all attached clients with
905  * the given arguments */
906 void i2c_clients_command(struct i2c_adapter *adap,
907 			 unsigned int cmd, void *arg);
908 
909 struct i2c_adapter *i2c_get_adapter(int nr);
910 void i2c_put_adapter(struct i2c_adapter *adap);
911 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
912 
913 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
914 
915 /* Return the functionality mask */
i2c_get_functionality(struct i2c_adapter * adap)916 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
917 {
918 	return adap->algo->functionality(adap);
919 }
920 
921 /* Return 1 if adapter supports everything we need, 0 if not. */
i2c_check_functionality(struct i2c_adapter * adap,u32 func)922 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
923 {
924 	return (func & i2c_get_functionality(adap)) == func;
925 }
926 
927 /**
928  * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
929  * @adap: i2c adapter
930  * @quirks: quirk flags
931  *
932  * Return: true if the adapter has all the specified quirk flags, false if not
933  */
i2c_check_quirks(struct i2c_adapter * adap,u64 quirks)934 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
935 {
936 	if (!adap->quirks)
937 		return false;
938 	return (adap->quirks->flags & quirks) == quirks;
939 }
940 
941 /* Return the adapter number for a specific adapter */
i2c_adapter_id(struct i2c_adapter * adap)942 static inline int i2c_adapter_id(struct i2c_adapter *adap)
943 {
944 	return adap->nr;
945 }
946 
i2c_8bit_addr_from_msg(const struct i2c_msg * msg)947 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
948 {
949 	return (msg->addr << 1) | (msg->flags & I2C_M_RD);
950 }
951 
952 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
953 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
954 
955 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
956 /**
957  * module_i2c_driver() - Helper macro for registering a modular I2C driver
958  * @__i2c_driver: i2c_driver struct
959  *
960  * Helper macro for I2C drivers which do not do anything special in module
961  * init/exit. This eliminates a lot of boilerplate. Each module may only
962  * use this macro once, and calling it replaces module_init() and module_exit()
963  */
964 #define module_i2c_driver(__i2c_driver) \
965 	module_driver(__i2c_driver, i2c_add_driver, \
966 			i2c_del_driver)
967 
968 /**
969  * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
970  * @__i2c_driver: i2c_driver struct
971  *
972  * Helper macro for I2C drivers which do not do anything special in their
973  * init. This eliminates a lot of boilerplate. Each driver may only
974  * use this macro once, and calling it replaces device_initcall().
975  */
976 #define builtin_i2c_driver(__i2c_driver) \
977 	builtin_driver(__i2c_driver, i2c_add_driver)
978 
979 /* must call put_device() when done with returned i2c_client device */
980 struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode);
981 
982 /* must call put_device() when done with returned i2c_adapter device */
983 struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode);
984 
985 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
986 struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode);
987 
988 #else /* I2C */
989 
990 static inline struct i2c_client *
i2c_find_device_by_fwnode(struct fwnode_handle * fwnode)991 i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
992 {
993 	return NULL;
994 }
995 
996 static inline struct i2c_adapter *
i2c_find_adapter_by_fwnode(struct fwnode_handle * fwnode)997 i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
998 {
999 	return NULL;
1000 }
1001 
1002 static inline struct i2c_adapter *
i2c_get_adapter_by_fwnode(struct fwnode_handle * fwnode)1003 i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)
1004 {
1005 	return NULL;
1006 }
1007 
1008 #endif /* !I2C */
1009 
1010 #if IS_ENABLED(CONFIG_OF)
1011 /* must call put_device() when done with returned i2c_client device */
of_find_i2c_device_by_node(struct device_node * node)1012 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1013 {
1014 	return i2c_find_device_by_fwnode(of_fwnode_handle(node));
1015 }
1016 
1017 /* must call put_device() when done with returned i2c_adapter device */
of_find_i2c_adapter_by_node(struct device_node * node)1018 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1019 {
1020 	return i2c_find_adapter_by_fwnode(of_fwnode_handle(node));
1021 }
1022 
1023 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
of_get_i2c_adapter_by_node(struct device_node * node)1024 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1025 {
1026 	return i2c_get_adapter_by_fwnode(of_fwnode_handle(node));
1027 }
1028 
1029 const struct of_device_id
1030 *i2c_of_match_device(const struct of_device_id *matches,
1031 		     struct i2c_client *client);
1032 
1033 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
1034 			  struct i2c_board_info *info);
1035 
1036 #else
1037 
of_find_i2c_device_by_node(struct device_node * node)1038 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1039 {
1040 	return NULL;
1041 }
1042 
of_find_i2c_adapter_by_node(struct device_node * node)1043 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1044 {
1045 	return NULL;
1046 }
1047 
of_get_i2c_adapter_by_node(struct device_node * node)1048 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1049 {
1050 	return NULL;
1051 }
1052 
1053 static inline const struct of_device_id
i2c_of_match_device(const struct of_device_id * matches,struct i2c_client * client)1054 *i2c_of_match_device(const struct of_device_id *matches,
1055 		     struct i2c_client *client)
1056 {
1057 	return NULL;
1058 }
1059 
of_i2c_get_board_info(struct device * dev,struct device_node * node,struct i2c_board_info * info)1060 static inline int of_i2c_get_board_info(struct device *dev,
1061 					struct device_node *node,
1062 					struct i2c_board_info *info)
1063 {
1064 	return -ENOTSUPP;
1065 }
1066 
1067 #endif /* CONFIG_OF */
1068 
1069 struct acpi_resource;
1070 struct acpi_resource_i2c_serialbus;
1071 
1072 #if IS_REACHABLE(CONFIG_ACPI) && IS_REACHABLE(CONFIG_I2C)
1073 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1074 			       struct acpi_resource_i2c_serialbus **i2c);
1075 int i2c_acpi_client_count(struct acpi_device *adev);
1076 u32 i2c_acpi_find_bus_speed(struct device *dev);
1077 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1078 						 int index,
1079 						 struct i2c_board_info *info);
1080 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1081 bool i2c_acpi_waive_d0_probe(struct device *dev);
1082 #else
i2c_acpi_get_i2c_resource(struct acpi_resource * ares,struct acpi_resource_i2c_serialbus ** i2c)1083 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1084 					     struct acpi_resource_i2c_serialbus **i2c)
1085 {
1086 	return false;
1087 }
i2c_acpi_client_count(struct acpi_device * adev)1088 static inline int i2c_acpi_client_count(struct acpi_device *adev)
1089 {
1090 	return 0;
1091 }
i2c_acpi_find_bus_speed(struct device * dev)1092 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1093 {
1094 	return 0;
1095 }
i2c_acpi_new_device_by_fwnode(struct fwnode_handle * fwnode,int index,struct i2c_board_info * info)1096 static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1097 					struct fwnode_handle *fwnode, int index,
1098 					struct i2c_board_info *info)
1099 {
1100 	return ERR_PTR(-ENODEV);
1101 }
i2c_acpi_find_adapter_by_handle(acpi_handle handle)1102 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1103 {
1104 	return NULL;
1105 }
i2c_acpi_waive_d0_probe(struct device * dev)1106 static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1107 {
1108 	return false;
1109 }
1110 #endif /* CONFIG_ACPI */
1111 
i2c_acpi_new_device(struct device * dev,int index,struct i2c_board_info * info)1112 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1113 						     int index,
1114 						     struct i2c_board_info *info)
1115 {
1116 	return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1117 }
1118 
1119 #endif /* _LINUX_I2C_H */
1120