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 */
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 */
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 */
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 */
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
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
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
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
368 static inline void *i2c_get_clientdata(const struct i2c_client *client)
369 {
370 return dev_get_drvdata(&client->dev);
371 }
372
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
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
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
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
770 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
771 {
772 return dev_get_drvdata(&adap->dev);
773 }
774
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 *
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
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
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
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 */
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 */
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
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 */
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. */
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 */
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 */
942 static inline int i2c_adapter_id(struct i2c_adapter *adap)
943 {
944 return adap->nr;
945 }
946
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 *
991 i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
992 {
993 return NULL;
994 }
995
996 static inline struct i2c_adapter *
997 i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
998 {
999 return NULL;
1000 }
1001
1002 static inline struct i2c_adapter *
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 */
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 */
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 */
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
1038 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1039 {
1040 return NULL;
1041 }
1042
1043 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1044 {
1045 return NULL;
1046 }
1047
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
1054 *i2c_of_match_device(const struct of_device_id *matches,
1055 struct i2c_client *client)
1056 {
1057 return NULL;
1058 }
1059
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
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 }
1088 static inline int i2c_acpi_client_count(struct acpi_device *adev)
1089 {
1090 return 0;
1091 }
1092 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1093 {
1094 return 0;
1095 }
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 }
1102 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1103 {
1104 return NULL;
1105 }
1106 static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1107 {
1108 return false;
1109 }
1110 #endif /* CONFIG_ACPI */
1111
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
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