xref: /linux/include/linux/i2c.h (revision 3dd7b8123544402be76bea82af43d2de4b9226d8)
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  * @debugfs: pointer to the debugfs subdirectory which the I2C core created
325  *	for this client.
326  *
327  * An i2c_client identifies a single device (i.e. chip) connected to an
328  * i2c bus. The behaviour exposed to Linux is defined by the driver
329  * managing the device.
330  */
331 struct i2c_client {
332 	unsigned short flags;		/* div., see below		*/
333 #define I2C_CLIENT_PEC		0x04	/* Use Packet Error Checking */
334 #define I2C_CLIENT_TEN		0x10	/* we have a ten bit chip address */
335 					/* Must equal I2C_M_TEN below */
336 #define I2C_CLIENT_SLAVE	0x20	/* we are the slave */
337 #define I2C_CLIENT_HOST_NOTIFY	0x40	/* We want to use I2C host notify */
338 #define I2C_CLIENT_WAKE		0x80	/* for board_info; true iff can wake */
339 #define I2C_CLIENT_SCCB		0x9000	/* Use Omnivision SCCB protocol */
340 					/* Must match I2C_M_STOP|IGNORE_NAK */
341 
342 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
343 					/* addresses are stored in the	*/
344 					/* _LOWER_ 7 bits		*/
345 	char name[I2C_NAME_SIZE];
346 	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
347 	struct device dev;		/* the device structure		*/
348 	int init_irq;			/* irq set at initialization	*/
349 	int irq;			/* irq issued by device		*/
350 	struct list_head detected;
351 #if IS_ENABLED(CONFIG_I2C_SLAVE)
352 	i2c_slave_cb_t slave_cb;	/* callback for slave mode	*/
353 #endif
354 	void *devres_group_id;		/* ID of probe devres group	*/
355 	struct dentry *debugfs;		/* per-client debugfs dir	*/
356 };
357 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
358 
359 struct i2c_adapter *i2c_verify_adapter(struct device *dev);
360 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
361 					 const struct i2c_client *client);
362 
363 const void *i2c_get_match_data(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 enum i2c_slave_event {
384 	I2C_SLAVE_READ_REQUESTED,
385 	I2C_SLAVE_WRITE_REQUESTED,
386 	I2C_SLAVE_READ_PROCESSED,
387 	I2C_SLAVE_WRITE_RECEIVED,
388 	I2C_SLAVE_STOP,
389 };
390 
391 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
392 int i2c_slave_unregister(struct i2c_client *client);
393 int i2c_slave_event(struct i2c_client *client,
394 		    enum i2c_slave_event event, u8 *val);
395 #if IS_ENABLED(CONFIG_I2C_SLAVE)
396 bool i2c_detect_slave_mode(struct device *dev);
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  * @fwnode: device node supplied by the platform firmware
409  * @swnode: software node for the device
410  * @resources: resources associated with the device
411  * @num_resources: number of resources in the @resources array
412  * @irq: stored in i2c_client.irq
413  *
414  * I2C doesn't actually support hardware probing, although controllers and
415  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
416  * a device at a given address.  Drivers commonly need more information than
417  * that, such as chip type, configuration, associated IRQ, and so on.
418  *
419  * i2c_board_info is used to build tables of information listing I2C devices
420  * that are present.  This information is used to grow the driver model tree.
421  * For mainboards this is done statically using i2c_register_board_info();
422  * bus numbers identify adapters that aren't yet available.  For add-on boards,
423  * i2c_new_client_device() does this dynamically with the adapter already known.
424  */
425 struct i2c_board_info {
426 	char		type[I2C_NAME_SIZE];
427 	unsigned short	flags;
428 	unsigned short	addr;
429 	const char	*dev_name;
430 	void		*platform_data;
431 	struct fwnode_handle *fwnode;
432 	const struct software_node *swnode;
433 	const struct resource *resources;
434 	unsigned int	num_resources;
435 	int		irq;
436 };
437 
438 /**
439  * I2C_BOARD_INFO - macro used to list an i2c device and its address
440  * @dev_type: identifies the device type
441  * @dev_addr: the device's address on the bus.
442  *
443  * This macro initializes essential fields of a struct i2c_board_info,
444  * declaring what has been provided on a particular board.  Optional
445  * fields (such as associated irq, or device-specific platform_data)
446  * are provided using conventional syntax.
447  */
448 #define I2C_BOARD_INFO(dev_type, dev_addr) \
449 	.type = dev_type, .addr = (dev_addr)
450 
451 
452 #if IS_ENABLED(CONFIG_I2C)
453 /*
454  * Add-on boards should register/unregister their devices; e.g. a board
455  * with integrated I2C, a config eeprom, sensors, and a codec that's
456  * used in conjunction with the primary hardware.
457  */
458 struct i2c_client *
459 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
460 
461 /* If you don't know the exact address of an I2C device, use this variant
462  * instead, which can probe for device presence in a list of possible
463  * addresses. The "probe" callback function is optional. If it is provided,
464  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
465  * a default probing method is used.
466  */
467 struct i2c_client *
468 i2c_new_scanned_device(struct i2c_adapter *adap,
469 		       struct i2c_board_info *info,
470 		       unsigned short const *addr_list,
471 		       int (*probe)(struct i2c_adapter *adap, unsigned short addr));
472 
473 /* Common custom probe functions */
474 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
475 
476 struct i2c_client *
477 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
478 
479 struct i2c_client *
480 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
481 
482 struct i2c_client *
483 i2c_new_ancillary_device(struct i2c_client *client,
484 			 const char *name,
485 			 u16 default_addr);
486 
487 void i2c_unregister_device(struct i2c_client *client);
488 
489 struct i2c_client *i2c_verify_client(struct device *dev);
490 #else
i2c_verify_client(struct device * dev)491 static inline struct i2c_client *i2c_verify_client(struct device *dev)
492 {
493 	return NULL;
494 }
495 #endif /* I2C */
496 
497 /* Mainboard arch_initcall() code should register all its I2C devices.
498  * This is done at arch_initcall time, before declaring any i2c adapters.
499  * Modules for add-on boards must use other calls.
500  */
501 #ifdef CONFIG_I2C_BOARDINFO
502 int
503 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
504 			unsigned n);
505 #else
506 static inline int
i2c_register_board_info(int busnum,struct i2c_board_info const * info,unsigned n)507 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
508 			unsigned n)
509 {
510 	return 0;
511 }
512 #endif /* I2C_BOARDINFO */
513 
514 /**
515  * struct i2c_algorithm - represent I2C transfer methods
516  * @xfer: Transfer a given number of messages defined by the msgs array via
517  *   the specified adapter.
518  * @xfer_atomic: Same as @xfer. Yet, only using atomic context so e.g. PMICs
519  *   can be accessed very late before shutdown. Optional.
520  * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this
521  *   is not present, then the bus layer will try and convert the SMBus calls
522  *   into I2C transfers instead.
523  * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context
524  *   so e.g. PMICs can be accessed very late before shutdown. Optional.
525  * @functionality: Return the flags that this algorithm/adapter pair supports
526  *   from the ``I2C_FUNC_*`` flags.
527  * @reg_target: Register given client to local target mode of this adapter
528  * @unreg_target: Unregister given client from local target mode of this adapter
529  *
530  * @master_xfer: deprecated, use @xfer
531  * @master_xfer_atomic: deprecated, use @xfer_atomic
532  * @reg_slave: deprecated, use @reg_target
533  * @unreg_slave: deprecated, use @unreg_target
534  *
535  * i2c_algorithm is the interface to a class of hardware solutions which can
536  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
537  * to name two of the most common.
538  *
539  * The return codes from the ``xfer{_atomic}`` fields should indicate the
540  * type of error code that occurred during the transfer, as documented in the
541  * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
542  * number of messages executed should be returned.
543  */
544 struct i2c_algorithm {
545 	/*
546 	 * If an adapter algorithm can't do I2C-level access, set xfer
547 	 * to NULL. If an adapter algorithm can do SMBus access, set
548 	 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
549 	 * using common I2C messages.
550 	 */
551 	union {
552 		int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
553 			    int num);
554 		int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
555 				   int num);
556 	};
557 	union {
558 		int (*xfer_atomic)(struct i2c_adapter *adap,
559 				   struct i2c_msg *msgs, int num);
560 		int (*master_xfer_atomic)(struct i2c_adapter *adap,
561 					   struct i2c_msg *msgs, int num);
562 	};
563 	int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
564 			  unsigned short flags, char read_write,
565 			  u8 command, int size, union i2c_smbus_data *data);
566 	int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
567 				 unsigned short flags, char read_write,
568 				 u8 command, int size, union i2c_smbus_data *data);
569 
570 	/* To determine what the adapter supports */
571 	u32 (*functionality)(struct i2c_adapter *adap);
572 
573 #if IS_ENABLED(CONFIG_I2C_SLAVE)
574 	union {
575 		int (*reg_target)(struct i2c_client *client);
576 		int (*reg_slave)(struct i2c_client *client);
577 	};
578 	union {
579 		int (*unreg_target)(struct i2c_client *client);
580 		int (*unreg_slave)(struct i2c_client *client);
581 	};
582 #endif
583 };
584 
585 /**
586  * struct i2c_lock_operations - represent I2C locking operations
587  * @lock_bus: Get exclusive access to an I2C bus segment
588  * @trylock_bus: Try to get exclusive access to an I2C bus segment
589  * @unlock_bus: Release exclusive access to an I2C bus segment
590  *
591  * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
592  */
593 struct i2c_lock_operations {
594 	void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
595 	int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
596 	void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
597 };
598 
599 /**
600  * struct i2c_timings - I2C timing information
601  * @bus_freq_hz: the bus frequency in Hz
602  * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
603  * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
604  * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
605  * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
606  * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
607  * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
608  *	digital filter can filter out
609  * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
610  *	analog filter
611  */
612 struct i2c_timings {
613 	u32 bus_freq_hz;
614 	u32 scl_rise_ns;
615 	u32 scl_fall_ns;
616 	u32 scl_int_delay_ns;
617 	u32 sda_fall_ns;
618 	u32 sda_hold_ns;
619 	u32 digital_filter_width_ns;
620 	u32 analog_filter_cutoff_freq_hz;
621 };
622 
623 /**
624  * struct i2c_bus_recovery_info - I2C bus recovery information
625  * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
626  *	i2c_generic_scl_recovery().
627  * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
628  *      recovery. Populated internally for generic GPIO recovery.
629  * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
630  *      Populated internally for generic GPIO recovery.
631  * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
632  *	for generic SCL recovery. Populated internally, if sda_gpio is a valid
633  *	GPIO, for generic GPIO recovery.
634  * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
635  *	generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
636  *	for generic GPIO recovery.
637  * @get_bus_free: Returns the bus free state as seen from the IP core in case it
638  *	has a more complex internal logic than just reading SDA. Optional.
639  * @prepare_recovery: This will be called before starting recovery. Platform may
640  *	configure padmux here for SDA/SCL line or something else they want.
641  * @unprepare_recovery: This will be called after completing recovery. Platform
642  *	may configure padmux here for SDA/SCL line or something else they want.
643  * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
644  * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
645  * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
646  *      Optional.
647  * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
648  *      to the I2C bus. Optional. Populated internally for GPIO recovery, if
649  *      state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
650  * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
651  *      GPIOs. Optional. Populated internally for GPIO recovery, if this state
652  *      is called "gpio" or "recovery" and pinctrl is valid.
653  */
654 struct i2c_bus_recovery_info {
655 	int (*recover_bus)(struct i2c_adapter *adap);
656 
657 	int (*get_scl)(struct i2c_adapter *adap);
658 	void (*set_scl)(struct i2c_adapter *adap, int val);
659 	int (*get_sda)(struct i2c_adapter *adap);
660 	void (*set_sda)(struct i2c_adapter *adap, int val);
661 	int (*get_bus_free)(struct i2c_adapter *adap);
662 
663 	void (*prepare_recovery)(struct i2c_adapter *adap);
664 	void (*unprepare_recovery)(struct i2c_adapter *adap);
665 
666 	/* gpio recovery */
667 	struct gpio_desc *scl_gpiod;
668 	struct gpio_desc *sda_gpiod;
669 	struct pinctrl *pinctrl;
670 	struct pinctrl_state *pins_default;
671 	struct pinctrl_state *pins_gpio;
672 };
673 
674 int i2c_recover_bus(struct i2c_adapter *adap);
675 
676 /* Generic recovery routines */
677 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
678 
679 /**
680  * struct i2c_adapter_quirks - describe flaws of an i2c adapter
681  * @flags: see I2C_AQ_* for possible flags and read below
682  * @max_num_msgs: maximum number of messages per transfer
683  * @max_write_len: maximum length of a write message
684  * @max_read_len: maximum length of a read message
685  * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
686  * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
687  *
688  * Note about combined messages: Some I2C controllers can only send one message
689  * per transfer, plus something called combined message or write-then-read.
690  * This is (usually) a small write message followed by a read message and
691  * barely enough to access register based devices like EEPROMs. There is a flag
692  * to support this mode. It implies max_num_msg = 2 and does the length checks
693  * with max_comb_*_len because combined message mode usually has its own
694  * limitations. Because of HW implementations, some controllers can actually do
695  * write-then-anything or other variants. To support that, write-then-read has
696  * been broken out into smaller bits like write-first and read-second which can
697  * be combined as needed.
698  */
699 
700 struct i2c_adapter_quirks {
701 	u64 flags;
702 	int max_num_msgs;
703 	u16 max_write_len;
704 	u16 max_read_len;
705 	u16 max_comb_1st_msg_len;
706 	u16 max_comb_2nd_msg_len;
707 };
708 
709 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
710 #define I2C_AQ_COMB			BIT(0)
711 /* first combined message must be write */
712 #define I2C_AQ_COMB_WRITE_FIRST		BIT(1)
713 /* second combined message must be read */
714 #define I2C_AQ_COMB_READ_SECOND		BIT(2)
715 /* both combined messages must have the same target address */
716 #define I2C_AQ_COMB_SAME_ADDR		BIT(3)
717 /* convenience macro for typical write-then read case */
718 #define I2C_AQ_COMB_WRITE_THEN_READ	(I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
719 					 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
720 /* clock stretching is not supported */
721 #define I2C_AQ_NO_CLK_STRETCH		BIT(4)
722 /* message cannot have length of 0 */
723 #define I2C_AQ_NO_ZERO_LEN_READ		BIT(5)
724 #define I2C_AQ_NO_ZERO_LEN_WRITE	BIT(6)
725 #define I2C_AQ_NO_ZERO_LEN		(I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
726 /* adapter cannot do repeated START */
727 #define I2C_AQ_NO_REP_START		BIT(7)
728 
729 /*
730  * i2c_adapter is the structure used to identify a physical i2c bus along
731  * with the access algorithms necessary to access it.
732  */
733 struct i2c_adapter {
734 	struct module *owner;
735 	unsigned int class;		  /* classes to allow probing for */
736 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
737 	void *algo_data;
738 
739 	/* data fields that are valid for all devices	*/
740 	const struct i2c_lock_operations *lock_ops;
741 	struct rt_mutex bus_lock;
742 	struct rt_mutex mux_lock;
743 
744 	int timeout;			/* in jiffies */
745 	int retries;
746 	struct device dev;		/* the adapter device */
747 	unsigned long locked_flags;	/* owned by the I2C core */
748 #define I2C_ALF_IS_SUSPENDED		0
749 #define I2C_ALF_SUSPEND_REPORTED	1
750 
751 	int nr;
752 	char name[48];
753 	struct completion dev_released;
754 
755 	struct mutex userspace_clients_lock;
756 	struct list_head userspace_clients;
757 
758 	struct i2c_bus_recovery_info *bus_recovery_info;
759 	const struct i2c_adapter_quirks *quirks;
760 
761 	struct irq_domain *host_notify_domain;
762 	struct regulator *bus_regulator;
763 
764 	struct dentry *debugfs;
765 
766 	/* 7bit address space */
767 	DECLARE_BITMAP(addrs_in_instantiation, 1 << 7);
768 };
769 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
770 
i2c_get_adapdata(const struct i2c_adapter * adap)771 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
772 {
773 	return dev_get_drvdata(&adap->dev);
774 }
775 
i2c_set_adapdata(struct i2c_adapter * adap,void * data)776 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
777 {
778 	dev_set_drvdata(&adap->dev, data);
779 }
780 
781 static inline struct i2c_adapter *
i2c_parent_is_i2c_adapter(const struct i2c_adapter * adapter)782 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
783 {
784 #if IS_ENABLED(CONFIG_I2C_MUX)
785 	struct device *parent = adapter->dev.parent;
786 
787 	if (parent != NULL && parent->type == &i2c_adapter_type)
788 		return to_i2c_adapter(parent);
789 	else
790 #endif
791 		return NULL;
792 }
793 
794 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
795 
796 /* Adapter locking functions, exported for shared pin cases */
797 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
798 #define I2C_LOCK_SEGMENT      BIT(1)
799 
800 /**
801  * i2c_lock_bus - Get exclusive access to an I2C bus segment
802  * @adapter: Target I2C bus segment
803  * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
804  *	locks only this branch in the adapter tree
805  */
806 static inline void
i2c_lock_bus(struct i2c_adapter * adapter,unsigned int flags)807 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
808 {
809 	adapter->lock_ops->lock_bus(adapter, flags);
810 }
811 
812 /**
813  * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
814  * @adapter: Target I2C bus segment
815  * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
816  *	I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
817  *
818  * Return: true if the I2C bus segment is locked, false otherwise
819  */
820 static inline int
i2c_trylock_bus(struct i2c_adapter * adapter,unsigned int flags)821 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
822 {
823 	return adapter->lock_ops->trylock_bus(adapter, flags);
824 }
825 
826 /**
827  * i2c_unlock_bus - Release exclusive access to an I2C bus segment
828  * @adapter: Target I2C bus segment
829  * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
830  *	unlocks only this branch in the adapter tree
831  */
832 static inline void
i2c_unlock_bus(struct i2c_adapter * adapter,unsigned int flags)833 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
834 {
835 	adapter->lock_ops->unlock_bus(adapter, flags);
836 }
837 
838 /**
839  * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
840  * @adap: Adapter to mark as suspended
841  *
842  * When using this helper to mark an adapter as suspended, the core will reject
843  * further transfers to this adapter. The usage of this helper is optional but
844  * recommended for devices having distinct handlers for system suspend and
845  * runtime suspend. More complex devices are free to implement custom solutions
846  * to reject transfers when suspended.
847  */
i2c_mark_adapter_suspended(struct i2c_adapter * adap)848 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
849 {
850 	i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
851 	set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
852 	i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
853 }
854 
855 /**
856  * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
857  * @adap: Adapter to mark as resumed
858  *
859  * When using this helper to mark an adapter as resumed, the core will allow
860  * further transfers to this adapter. See also further notes to
861  * @i2c_mark_adapter_suspended().
862  */
i2c_mark_adapter_resumed(struct i2c_adapter * adap)863 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
864 {
865 	i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
866 	clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
867 	i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
868 }
869 
870 /* i2c adapter classes (bitmask) */
871 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
872 /* Warn users that the adapter doesn't support classes anymore */
873 #define I2C_CLASS_DEPRECATED	(1<<8)
874 
875 /* Internal numbers to terminate lists */
876 #define I2C_CLIENT_END		0xfffeU
877 
878 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
879 #define I2C_ADDRS(addr, addrs...) \
880 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
881 
882 
883 /* ----- functions exported by i2c.o */
884 
885 /* administration...
886  */
887 #if IS_ENABLED(CONFIG_I2C)
888 int i2c_add_adapter(struct i2c_adapter *adap);
889 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
890 void i2c_del_adapter(struct i2c_adapter *adap);
891 int i2c_add_numbered_adapter(struct i2c_adapter *adap);
892 
893 int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
894 void i2c_del_driver(struct i2c_driver *driver);
895 
896 /* use a define to avoid include chaining to get THIS_MODULE */
897 #define i2c_add_driver(driver) \
898 	i2c_register_driver(THIS_MODULE, driver)
899 
i2c_client_has_driver(struct i2c_client * client)900 static inline bool i2c_client_has_driver(struct i2c_client *client)
901 {
902 	return !IS_ERR_OR_NULL(client) && client->dev.driver;
903 }
904 
905 /* call the i2c_client->command() of all attached clients with
906  * the given arguments */
907 void i2c_clients_command(struct i2c_adapter *adap,
908 			 unsigned int cmd, void *arg);
909 
910 struct i2c_adapter *i2c_get_adapter(int nr);
911 void i2c_put_adapter(struct i2c_adapter *adap);
912 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
913 
914 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
915 
916 /* Return the functionality mask */
i2c_get_functionality(struct i2c_adapter * adap)917 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
918 {
919 	return adap->algo->functionality(adap);
920 }
921 
922 /* Return 1 if adapter supports everything we need, 0 if not. */
i2c_check_functionality(struct i2c_adapter * adap,u32 func)923 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
924 {
925 	return (func & i2c_get_functionality(adap)) == func;
926 }
927 
928 /**
929  * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
930  * @adap: i2c adapter
931  * @quirks: quirk flags
932  *
933  * Return: true if the adapter has all the specified quirk flags, false if not
934  */
i2c_check_quirks(struct i2c_adapter * adap,u64 quirks)935 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
936 {
937 	if (!adap->quirks)
938 		return false;
939 	return (adap->quirks->flags & quirks) == quirks;
940 }
941 
942 /* Return the adapter number for a specific adapter */
i2c_adapter_id(struct i2c_adapter * adap)943 static inline int i2c_adapter_id(struct i2c_adapter *adap)
944 {
945 	return adap->nr;
946 }
947 
i2c_8bit_addr_from_msg(const struct i2c_msg * msg)948 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
949 {
950 	return (msg->addr << 1) | (msg->flags & I2C_M_RD);
951 }
952 
953 /*
954  * 10-bit address
955  *   addr_1: 5'b11110 | addr[9:8] | (R/nW)
956  *   addr_2: addr[7:0]
957  */
i2c_10bit_addr_hi_from_msg(const struct i2c_msg * msg)958 static inline u8 i2c_10bit_addr_hi_from_msg(const struct i2c_msg *msg)
959 {
960 	return 0xf0 | ((msg->addr & GENMASK(9, 8)) >> 7) | (msg->flags & I2C_M_RD);
961 }
962 
i2c_10bit_addr_lo_from_msg(const struct i2c_msg * msg)963 static inline u8 i2c_10bit_addr_lo_from_msg(const struct i2c_msg *msg)
964 {
965 	return msg->addr & GENMASK(7, 0);
966 }
967 
968 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
969 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
970 
971 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
972 /**
973  * module_i2c_driver() - Helper macro for registering a modular I2C driver
974  * @__i2c_driver: i2c_driver struct
975  *
976  * Helper macro for I2C drivers which do not do anything special in module
977  * init/exit. This eliminates a lot of boilerplate. Each module may only
978  * use this macro once, and calling it replaces module_init() and module_exit()
979  */
980 #define module_i2c_driver(__i2c_driver) \
981 	module_driver(__i2c_driver, i2c_add_driver, \
982 			i2c_del_driver)
983 
984 /**
985  * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
986  * @__i2c_driver: i2c_driver struct
987  *
988  * Helper macro for I2C drivers which do not do anything special in their
989  * init. This eliminates a lot of boilerplate. Each driver may only
990  * use this macro once, and calling it replaces device_initcall().
991  */
992 #define builtin_i2c_driver(__i2c_driver) \
993 	builtin_driver(__i2c_driver, i2c_add_driver)
994 
995 /* must call put_device() when done with returned i2c_client device */
996 struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode);
997 
998 /* must call put_device() when done with returned i2c_adapter device */
999 struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode);
1000 
1001 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
1002 struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode);
1003 
1004 #else /* I2C */
1005 
1006 static inline struct i2c_client *
i2c_find_device_by_fwnode(struct fwnode_handle * fwnode)1007 i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
1008 {
1009 	return NULL;
1010 }
1011 
1012 static inline struct i2c_adapter *
i2c_find_adapter_by_fwnode(struct fwnode_handle * fwnode)1013 i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
1014 {
1015 	return NULL;
1016 }
1017 
1018 static inline struct i2c_adapter *
i2c_get_adapter_by_fwnode(struct fwnode_handle * fwnode)1019 i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)
1020 {
1021 	return NULL;
1022 }
1023 
1024 #endif /* !I2C */
1025 
1026 #if IS_ENABLED(CONFIG_OF)
1027 /* must call put_device() when done with returned i2c_client device */
of_find_i2c_device_by_node(struct device_node * node)1028 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1029 {
1030 	return i2c_find_device_by_fwnode(of_fwnode_handle(node));
1031 }
1032 
1033 /* must call put_device() when done with returned i2c_adapter device */
of_find_i2c_adapter_by_node(struct device_node * node)1034 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1035 {
1036 	return i2c_find_adapter_by_fwnode(of_fwnode_handle(node));
1037 }
1038 
1039 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
of_get_i2c_adapter_by_node(struct device_node * node)1040 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1041 {
1042 	return i2c_get_adapter_by_fwnode(of_fwnode_handle(node));
1043 }
1044 
1045 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
1046 			  struct i2c_board_info *info);
1047 
1048 #else
1049 
of_find_i2c_device_by_node(struct device_node * node)1050 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1051 {
1052 	return NULL;
1053 }
1054 
of_find_i2c_adapter_by_node(struct device_node * node)1055 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1056 {
1057 	return NULL;
1058 }
1059 
of_get_i2c_adapter_by_node(struct device_node * node)1060 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1061 {
1062 	return NULL;
1063 }
1064 
of_i2c_get_board_info(struct device * dev,struct device_node * node,struct i2c_board_info * info)1065 static inline int of_i2c_get_board_info(struct device *dev,
1066 					struct device_node *node,
1067 					struct i2c_board_info *info)
1068 {
1069 	return -ENOTSUPP;
1070 }
1071 
1072 #endif /* CONFIG_OF */
1073 
1074 struct acpi_resource;
1075 struct acpi_resource_i2c_serialbus;
1076 
1077 #if IS_REACHABLE(CONFIG_ACPI) && IS_REACHABLE(CONFIG_I2C)
1078 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1079 			       struct acpi_resource_i2c_serialbus **i2c);
1080 int i2c_acpi_client_count(struct acpi_device *adev);
1081 u32 i2c_acpi_find_bus_speed(struct device *dev);
1082 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1083 						 int index,
1084 						 struct i2c_board_info *info);
1085 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1086 bool i2c_acpi_waive_d0_probe(struct device *dev);
1087 #else
i2c_acpi_get_i2c_resource(struct acpi_resource * ares,struct acpi_resource_i2c_serialbus ** i2c)1088 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1089 					     struct acpi_resource_i2c_serialbus **i2c)
1090 {
1091 	return false;
1092 }
i2c_acpi_client_count(struct acpi_device * adev)1093 static inline int i2c_acpi_client_count(struct acpi_device *adev)
1094 {
1095 	return 0;
1096 }
i2c_acpi_find_bus_speed(struct device * dev)1097 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1098 {
1099 	return 0;
1100 }
i2c_acpi_new_device_by_fwnode(struct fwnode_handle * fwnode,int index,struct i2c_board_info * info)1101 static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1102 					struct fwnode_handle *fwnode, int index,
1103 					struct i2c_board_info *info)
1104 {
1105 	return ERR_PTR(-ENODEV);
1106 }
i2c_acpi_find_adapter_by_handle(acpi_handle handle)1107 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1108 {
1109 	return NULL;
1110 }
i2c_acpi_waive_d0_probe(struct device * dev)1111 static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1112 {
1113 	return false;
1114 }
1115 #endif /* CONFIG_ACPI */
1116 
i2c_acpi_new_device(struct device * dev,int index,struct i2c_board_info * info)1117 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1118 						     int index,
1119 						     struct i2c_board_info *info)
1120 {
1121 	return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1122 }
1123 
1124 #endif /* _LINUX_I2C_H */
1125