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@the-dreams.de>
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/mod_devicetable.h>
15 #include <linux/device.h> /* for struct device */
16 #include <linux/sched.h> /* for completion */
17 #include <linux/mutex.h>
18 #include <linux/rtmutex.h>
19 #include <linux/irqdomain.h> /* for Host Notify IRQ */
20 #include <linux/of.h> /* for struct device_node */
21 #include <linux/swab.h> /* for swab16 */
22 #include <uapi/linux/i2c.h>
23
24 extern struct bus_type i2c_bus_type;
25 extern struct device_type i2c_adapter_type;
26 extern struct device_type i2c_client_type;
27
28 /* --- General options ------------------------------------------------ */
29
30 struct i2c_msg;
31 struct i2c_algorithm;
32 struct i2c_adapter;
33 struct i2c_client;
34 struct i2c_driver;
35 struct i2c_device_identity;
36 union i2c_smbus_data;
37 struct i2c_board_info;
38 enum i2c_slave_event;
39 typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
40 enum i2c_slave_event event, u8 *val);
41
42 struct module;
43 struct property_entry;
44
45 #if IS_ENABLED(CONFIG_I2C)
46 /*
47 * The master routines are the ones normally used to transmit data to devices
48 * on a bus (or read from them). Apart from two basic transfer functions to
49 * transmit one message at a time, a more complex version can be used to
50 * transmit an arbitrary number of messages without interruption.
51 * @count must be be less than 64k since msg.len is u16.
52 */
53 extern int i2c_transfer_buffer_flags(const struct i2c_client *client,
54 char *buf, int count, u16 flags);
55
56 /**
57 * i2c_master_recv - issue a single I2C message in master receive mode
58 * @client: Handle to slave device
59 * @buf: Where to store data read from slave
60 * @count: How many bytes to read, must be less than 64k since msg.len is u16
61 *
62 * Returns negative errno, or else the number of bytes read.
63 */
64 static inline int i2c_master_recv(const struct i2c_client *client,
65 char *buf, int count)
66 {
67 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
68 };
69
70 /**
71 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
72 * using a DMA safe buffer
73 * @client: Handle to slave device
74 * @buf: Where to store data read from slave, must be safe to use with DMA
75 * @count: How many bytes to read, must be less than 64k since msg.len is u16
76 *
77 * Returns negative errno, or else the number of bytes read.
78 */
79 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
80 char *buf, int count)
81 {
82 return i2c_transfer_buffer_flags(client, buf, count,
83 I2C_M_RD | I2C_M_DMA_SAFE);
84 };
85
86 /**
87 * i2c_master_send - issue a single I2C message in master transmit mode
88 * @client: Handle to slave device
89 * @buf: Data that will be written to the slave
90 * @count: How many bytes to write, must be less than 64k since msg.len is u16
91 *
92 * Returns negative errno, or else the number of bytes written.
93 */
94 static inline int i2c_master_send(const struct i2c_client *client,
95 const char *buf, int count)
96 {
97 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
98 };
99
100 /**
101 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
102 * using a DMA safe buffer
103 * @client: Handle to slave device
104 * @buf: Data that will be written to the slave, must be safe to use with DMA
105 * @count: How many bytes to write, must be less than 64k since msg.len is u16
106 *
107 * Returns negative errno, or else the number of bytes written.
108 */
109 static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
110 const char *buf, int count)
111 {
112 return i2c_transfer_buffer_flags(client, (char *)buf, count,
113 I2C_M_DMA_SAFE);
114 };
115
116 /* Transfer num messages.
117 */
118 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
119 int num);
120 /* Unlocked flavor */
121 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
122 int num);
123
124 /* This is the very generalized SMBus access routine. You probably do not
125 want to use this, though; one of the functions below may be much easier,
126 and probably just as fast.
127 Note that we use i2c_adapter here, because you do not need a specific
128 smbus adapter to call this function. */
129 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
130 unsigned short flags, char read_write, u8 command,
131 int protocol, union i2c_smbus_data *data);
132
133 /* Unlocked flavor */
134 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
135 unsigned short flags, char read_write, u8 command,
136 int protocol, union i2c_smbus_data *data);
137
138 /* Now follow the 'nice' access routines. These also document the calling
139 conventions of i2c_smbus_xfer. */
140
141 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
142 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
143 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
144 u8 command);
145 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
146 u8 command, u8 value);
147 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
148 u8 command);
149 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
150 u8 command, u16 value);
151
152 static inline s32
153 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
154 {
155 s32 value = i2c_smbus_read_word_data(client, command);
156
157 return (value < 0) ? value : swab16(value);
158 }
159
160 static inline s32
161 i2c_smbus_write_word_swapped(const struct i2c_client *client,
162 u8 command, u16 value)
163 {
164 return i2c_smbus_write_word_data(client, command, swab16(value));
165 }
166
167 /* Returns the number of read bytes */
168 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
169 u8 command, u8 *values);
170 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
171 u8 command, u8 length, const u8 *values);
172 /* Returns the number of read bytes */
173 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
174 u8 command, u8 length, u8 *values);
175 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
176 u8 command, u8 length,
177 const u8 *values);
178 extern s32
179 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
180 u8 command, u8 length, u8 *values);
181 int i2c_get_device_id(const struct i2c_client *client,
182 struct i2c_device_identity *id);
183 #endif /* I2C */
184
185 /**
186 * struct i2c_device_identity - i2c client device identification
187 * @manufacturer_id: 0 - 4095, database maintained by NXP
188 * @part_id: 0 - 511, according to manufacturer
189 * @die_revision: 0 - 7, according to manufacturer
190 */
191 struct i2c_device_identity {
192 u16 manufacturer_id;
193 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
194 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
195 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
197 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
198 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
199 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
200 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
201 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
202 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
203 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
204 #define I2C_DEVICE_ID_FLIR 11
205 #define I2C_DEVICE_ID_O2MICRO 12
206 #define I2C_DEVICE_ID_ATMEL 13
207 #define I2C_DEVICE_ID_NONE 0xffff
208 u16 part_id;
209 u8 die_revision;
210 };
211
212 enum i2c_alert_protocol {
213 I2C_PROTOCOL_SMBUS_ALERT,
214 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
215 };
216
217 /**
218 * struct i2c_driver - represent an I2C device driver
219 * @class: What kind of i2c device we instantiate (for detect)
220 * @probe: Callback for device binding - soon to be deprecated
221 * @probe_new: New callback for device binding
222 * @remove: Callback for device unbinding
223 * @shutdown: Callback for device shutdown
224 * @alert: Alert callback, for example for the SMBus alert protocol
225 * @command: Callback for bus-wide signaling (optional)
226 * @driver: Device driver model driver
227 * @id_table: List of I2C devices supported by this driver
228 * @detect: Callback for device detection
229 * @address_list: The I2C addresses to probe (for detect)
230 * @clients: List of detected clients we created (for i2c-core use only)
231 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
232 *
233 * The driver.owner field should be set to the module owner of this driver.
234 * The driver.name field should be set to the name of this driver.
235 *
236 * For automatic device detection, both @detect and @address_list must
237 * be defined. @class should also be set, otherwise only devices forced
238 * with module parameters will be created. The detect function must
239 * fill at least the name field of the i2c_board_info structure it is
240 * handed upon successful detection, and possibly also the flags field.
241 *
242 * If @detect is missing, the driver will still work fine for enumerated
243 * devices. Detected devices simply won't be supported. This is expected
244 * for the many I2C/SMBus devices which can't be detected reliably, and
245 * the ones which can always be enumerated in practice.
246 *
247 * The i2c_client structure which is handed to the @detect callback is
248 * not a real i2c_client. It is initialized just enough so that you can
249 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
250 * else with it. In particular, calling dev_dbg and friends on it is
251 * not allowed.
252 */
253 struct i2c_driver {
254 unsigned int class;
255
256 /* Standard driver model interfaces */
257 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
258 int (*remove)(struct i2c_client *client);
259
260 /* New driver model interface to aid the seamless removal of the
261 * current probe()'s, more commonly unused than used second parameter.
262 */
263 int (*probe_new)(struct i2c_client *client);
264
265 /* driver model interfaces that don't relate to enumeration */
266 void (*shutdown)(struct i2c_client *client);
267
268 /* Alert callback, for example for the SMBus alert protocol.
269 * The format and meaning of the data value depends on the protocol.
270 * For the SMBus alert protocol, there is a single bit of data passed
271 * as the alert response's low bit ("event flag").
272 * For the SMBus Host Notify protocol, the data corresponds to the
273 * 16-bit payload data reported by the slave device acting as master.
274 */
275 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
276 unsigned int data);
277
278 /* a ioctl like command that can be used to perform specific functions
279 * with the device.
280 */
281 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
282
283 struct device_driver driver;
284 const struct i2c_device_id *id_table;
285
286 /* Device detection callback for automatic device creation */
287 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
288 const unsigned short *address_list;
289 struct list_head clients;
290
291 bool disable_i2c_core_irq_mapping;
292 };
293 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
294
295 /**
296 * struct i2c_client - represent an I2C slave device
297 * @flags: see I2C_CLIENT_* for possible flags
298 * @addr: Address used on the I2C bus connected to the parent adapter.
299 * @name: Indicates the type of the device, usually a chip name that's
300 * generic enough to hide second-sourcing and compatible revisions.
301 * @adapter: manages the bus segment hosting this I2C device
302 * @dev: Driver model device node for the slave.
303 * @irq: indicates the IRQ generated by this device (if any)
304 * @detected: member of an i2c_driver.clients list or i2c-core's
305 * userspace_devices list
306 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
307 * calls it to pass on slave events to the slave driver.
308 *
309 * An i2c_client identifies a single device (i.e. chip) connected to an
310 * i2c bus. The behaviour exposed to Linux is defined by the driver
311 * managing the device.
312 */
313 struct i2c_client {
314 unsigned short flags; /* div., see below */
315 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
316 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
317 /* Must equal I2C_M_TEN below */
318 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
319 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
320 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
321 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
322 /* Must match I2C_M_STOP|IGNORE_NAK */
323
324 unsigned short addr; /* chip address - NOTE: 7bit */
325 /* addresses are stored in the */
326 /* _LOWER_ 7 bits */
327 char name[I2C_NAME_SIZE];
328 struct i2c_adapter *adapter; /* the adapter we sit on */
329 struct device dev; /* the device structure */
330 int init_irq; /* irq set at initialization */
331 int irq; /* irq issued by device */
332 struct list_head detected;
333 #if IS_ENABLED(CONFIG_I2C_SLAVE)
334 i2c_slave_cb_t slave_cb; /* callback for slave mode */
335 #endif
336 };
337 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
338
339 extern struct i2c_client *i2c_verify_client(struct device *dev);
340 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
341 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
342 const struct i2c_client *client);
343
344 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
345 {
346 struct device * const dev = container_of(kobj, struct device, kobj);
347 return to_i2c_client(dev);
348 }
349
350 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
351 {
352 return dev_get_drvdata(&dev->dev);
353 }
354
355 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
356 {
357 dev_set_drvdata(&dev->dev, data);
358 }
359
360 /* I2C slave support */
361
362 #if IS_ENABLED(CONFIG_I2C_SLAVE)
363 enum i2c_slave_event {
364 I2C_SLAVE_READ_REQUESTED,
365 I2C_SLAVE_WRITE_REQUESTED,
366 I2C_SLAVE_READ_PROCESSED,
367 I2C_SLAVE_WRITE_RECEIVED,
368 I2C_SLAVE_STOP,
369 };
370
371 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
372 extern int i2c_slave_unregister(struct i2c_client *client);
373 extern bool i2c_detect_slave_mode(struct device *dev);
374
375 static inline int i2c_slave_event(struct i2c_client *client,
376 enum i2c_slave_event event, u8 *val)
377 {
378 return client->slave_cb(client, event, val);
379 }
380 #else
381 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
382 #endif
383
384 /**
385 * struct i2c_board_info - template for device creation
386 * @type: chip type, to initialize i2c_client.name
387 * @flags: to initialize i2c_client.flags
388 * @addr: stored in i2c_client.addr
389 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
390 * @platform_data: stored in i2c_client.dev.platform_data
391 * @of_node: pointer to OpenFirmware device node
392 * @fwnode: device node supplied by the platform firmware
393 * @properties: additional device properties for the device
394 * @resources: resources associated with the device
395 * @num_resources: number of resources in the @resources array
396 * @irq: stored in i2c_client.irq
397 *
398 * I2C doesn't actually support hardware probing, although controllers and
399 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
400 * a device at a given address. Drivers commonly need more information than
401 * that, such as chip type, configuration, associated IRQ, and so on.
402 *
403 * i2c_board_info is used to build tables of information listing I2C devices
404 * that are present. This information is used to grow the driver model tree.
405 * For mainboards this is done statically using i2c_register_board_info();
406 * bus numbers identify adapters that aren't yet available. For add-on boards,
407 * i2c_new_device() does this dynamically with the adapter already known.
408 */
409 struct i2c_board_info {
410 char type[I2C_NAME_SIZE];
411 unsigned short flags;
412 unsigned short addr;
413 const char *dev_name;
414 void *platform_data;
415 struct device_node *of_node;
416 struct fwnode_handle *fwnode;
417 const struct property_entry *properties;
418 const struct resource *resources;
419 unsigned int num_resources;
420 int irq;
421 };
422
423 /**
424 * I2C_BOARD_INFO - macro used to list an i2c device and its address
425 * @dev_type: identifies the device type
426 * @dev_addr: the device's address on the bus.
427 *
428 * This macro initializes essential fields of a struct i2c_board_info,
429 * declaring what has been provided on a particular board. Optional
430 * fields (such as associated irq, or device-specific platform_data)
431 * are provided using conventional syntax.
432 */
433 #define I2C_BOARD_INFO(dev_type, dev_addr) \
434 .type = dev_type, .addr = (dev_addr)
435
436
437 #if IS_ENABLED(CONFIG_I2C)
438 /* Add-on boards should register/unregister their devices; e.g. a board
439 * with integrated I2C, a config eeprom, sensors, and a codec that's
440 * used in conjunction with the primary hardware.
441 */
442 extern struct i2c_client *
443 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
444
445 extern struct i2c_client *
446 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
447
448 /* If you don't know the exact address of an I2C device, use this variant
449 * instead, which can probe for device presence in a list of possible
450 * addresses. The "probe" callback function is optional. If it is provided,
451 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
452 * a default probing method is used.
453 */
454 extern struct i2c_client *
455 i2c_new_probed_device(struct i2c_adapter *adap,
456 struct i2c_board_info *info,
457 unsigned short const *addr_list,
458 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
459
460 /* Common custom probe functions */
461 extern int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
462
463 /* For devices that use several addresses, use i2c_new_dummy() to make
464 * client handles for the extra addresses.
465 */
466 extern struct i2c_client *
467 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
468
469 extern struct i2c_client *
470 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
471
472 extern struct i2c_client *
473 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
474
475 extern struct i2c_client *
476 i2c_new_ancillary_device(struct i2c_client *client,
477 const char *name,
478 u16 default_addr);
479
480 extern void i2c_unregister_device(struct i2c_client *client);
481 #endif /* I2C */
482
483 /* Mainboard arch_initcall() code should register all its I2C devices.
484 * This is done at arch_initcall time, before declaring any i2c adapters.
485 * Modules for add-on boards must use other calls.
486 */
487 #ifdef CONFIG_I2C_BOARDINFO
488 extern int
489 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
490 unsigned n);
491 #else
492 static inline int
493 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
494 unsigned n)
495 {
496 return 0;
497 }
498 #endif /* I2C_BOARDINFO */
499
500 /**
501 * struct i2c_algorithm - represent I2C transfer method
502 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
503 * defined by the msgs array, with num messages available to transfer via
504 * the adapter specified by adap.
505 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
506 * so e.g. PMICs can be accessed very late before shutdown. Optional.
507 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
508 * is not present, then the bus layer will try and convert the SMBus calls
509 * into I2C transfers instead.
510 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
511 * so e.g. PMICs can be accessed very late before shutdown. Optional.
512 * @functionality: Return the flags that this algorithm/adapter pair supports
513 * from the I2C_FUNC_* flags.
514 * @reg_slave: Register given client to I2C slave mode of this adapter
515 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
516 *
517 * The following structs are for those who like to implement new bus drivers:
518 * i2c_algorithm is the interface to a class of hardware solutions which can
519 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
520 * to name two of the most common.
521 *
522 * The return codes from the @master_xfer{_atomic} fields should indicate the
523 * type of error code that occurred during the transfer, as documented in the
524 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
525 */
526 struct i2c_algorithm {
527 /*
528 * If an adapter algorithm can't do I2C-level access, set master_xfer
529 * to NULL. If an adapter algorithm can do SMBus access, set
530 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
531 * using common I2C messages.
532 *
533 * master_xfer should return the number of messages successfully
534 * processed, or a negative value on error
535 */
536 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
537 int num);
538 int (*master_xfer_atomic)(struct i2c_adapter *adap,
539 struct i2c_msg *msgs, int num);
540 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
541 unsigned short flags, char read_write,
542 u8 command, int size, union i2c_smbus_data *data);
543 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
544 unsigned short flags, char read_write,
545 u8 command, int size, union i2c_smbus_data *data);
546
547 /* To determine what the adapter supports */
548 u32 (*functionality)(struct i2c_adapter *adap);
549
550 #if IS_ENABLED(CONFIG_I2C_SLAVE)
551 int (*reg_slave)(struct i2c_client *client);
552 int (*unreg_slave)(struct i2c_client *client);
553 #endif
554 };
555
556 /**
557 * struct i2c_lock_operations - represent I2C locking operations
558 * @lock_bus: Get exclusive access to an I2C bus segment
559 * @trylock_bus: Try to get exclusive access to an I2C bus segment
560 * @unlock_bus: Release exclusive access to an I2C bus segment
561 *
562 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
563 */
564 struct i2c_lock_operations {
565 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
566 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
567 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
568 };
569
570 /**
571 * struct i2c_timings - I2C timing information
572 * @bus_freq_hz: the bus frequency in Hz
573 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
574 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
575 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
576 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
577 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
578 */
579 struct i2c_timings {
580 u32 bus_freq_hz;
581 u32 scl_rise_ns;
582 u32 scl_fall_ns;
583 u32 scl_int_delay_ns;
584 u32 sda_fall_ns;
585 u32 sda_hold_ns;
586 };
587
588 /**
589 * struct i2c_bus_recovery_info - I2C bus recovery information
590 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
591 * i2c_generic_scl_recovery().
592 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
593 * recovery. Populated internally for generic GPIO recovery.
594 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
595 * Populated internally for generic GPIO recovery.
596 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
597 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
598 * GPIO, for generic GPIO recovery.
599 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
600 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
601 * for generic GPIO recovery.
602 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
603 * has a more complex internal logic than just reading SDA. Optional.
604 * @prepare_recovery: This will be called before starting recovery. Platform may
605 * configure padmux here for SDA/SCL line or something else they want.
606 * @unprepare_recovery: This will be called after completing recovery. Platform
607 * may configure padmux here for SDA/SCL line or something else they want.
608 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
609 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
610 */
611 struct i2c_bus_recovery_info {
612 int (*recover_bus)(struct i2c_adapter *adap);
613
614 int (*get_scl)(struct i2c_adapter *adap);
615 void (*set_scl)(struct i2c_adapter *adap, int val);
616 int (*get_sda)(struct i2c_adapter *adap);
617 void (*set_sda)(struct i2c_adapter *adap, int val);
618 int (*get_bus_free)(struct i2c_adapter *adap);
619
620 void (*prepare_recovery)(struct i2c_adapter *adap);
621 void (*unprepare_recovery)(struct i2c_adapter *adap);
622
623 /* gpio recovery */
624 struct gpio_desc *scl_gpiod;
625 struct gpio_desc *sda_gpiod;
626 };
627
628 int i2c_recover_bus(struct i2c_adapter *adap);
629
630 /* Generic recovery routines */
631 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
632
633 /**
634 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
635 * @flags: see I2C_AQ_* for possible flags and read below
636 * @max_num_msgs: maximum number of messages per transfer
637 * @max_write_len: maximum length of a write message
638 * @max_read_len: maximum length of a read message
639 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
640 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
641 *
642 * Note about combined messages: Some I2C controllers can only send one message
643 * per transfer, plus something called combined message or write-then-read.
644 * This is (usually) a small write message followed by a read message and
645 * barely enough to access register based devices like EEPROMs. There is a flag
646 * to support this mode. It implies max_num_msg = 2 and does the length checks
647 * with max_comb_*_len because combined message mode usually has its own
648 * limitations. Because of HW implementations, some controllers can actually do
649 * write-then-anything or other variants. To support that, write-then-read has
650 * been broken out into smaller bits like write-first and read-second which can
651 * be combined as needed.
652 */
653
654 struct i2c_adapter_quirks {
655 u64 flags;
656 int max_num_msgs;
657 u16 max_write_len;
658 u16 max_read_len;
659 u16 max_comb_1st_msg_len;
660 u16 max_comb_2nd_msg_len;
661 };
662
663 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
664 #define I2C_AQ_COMB BIT(0)
665 /* first combined message must be write */
666 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
667 /* second combined message must be read */
668 #define I2C_AQ_COMB_READ_SECOND BIT(2)
669 /* both combined messages must have the same target address */
670 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
671 /* convenience macro for typical write-then read case */
672 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
673 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
674 /* clock stretching is not supported */
675 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
676 /* message cannot have length of 0 */
677 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
678 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
679 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
680
681 /*
682 * i2c_adapter is the structure used to identify a physical i2c bus along
683 * with the access algorithms necessary to access it.
684 */
685 struct i2c_adapter {
686 struct module *owner;
687 unsigned int class; /* classes to allow probing for */
688 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
689 void *algo_data;
690
691 /* data fields that are valid for all devices */
692 const struct i2c_lock_operations *lock_ops;
693 struct rt_mutex bus_lock;
694 struct rt_mutex mux_lock;
695
696 int timeout; /* in jiffies */
697 int retries;
698 struct device dev; /* the adapter device */
699 unsigned long locked_flags; /* owned by the I2C core */
700 #define I2C_ALF_IS_SUSPENDED 0
701 #define I2C_ALF_SUSPEND_REPORTED 1
702
703 int nr;
704 char name[48];
705 struct completion dev_released;
706
707 struct mutex userspace_clients_lock;
708 struct list_head userspace_clients;
709
710 struct i2c_bus_recovery_info *bus_recovery_info;
711 const struct i2c_adapter_quirks *quirks;
712
713 struct irq_domain *host_notify_domain;
714 };
715 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
716
717 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
718 {
719 return dev_get_drvdata(&adap->dev);
720 }
721
722 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
723 {
724 dev_set_drvdata(&adap->dev, data);
725 }
726
727 static inline struct i2c_adapter *
728 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
729 {
730 #if IS_ENABLED(CONFIG_I2C_MUX)
731 struct device *parent = adapter->dev.parent;
732
733 if (parent != NULL && parent->type == &i2c_adapter_type)
734 return to_i2c_adapter(parent);
735 else
736 #endif
737 return NULL;
738 }
739
740 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
741
742 /* Adapter locking functions, exported for shared pin cases */
743 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
744 #define I2C_LOCK_SEGMENT BIT(1)
745
746 /**
747 * i2c_lock_bus - Get exclusive access to an I2C bus segment
748 * @adapter: Target I2C bus segment
749 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
750 * locks only this branch in the adapter tree
751 */
752 static inline void
753 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
754 {
755 adapter->lock_ops->lock_bus(adapter, flags);
756 }
757
758 /**
759 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
760 * @adapter: Target I2C bus segment
761 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
762 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
763 *
764 * Return: true if the I2C bus segment is locked, false otherwise
765 */
766 static inline int
767 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
768 {
769 return adapter->lock_ops->trylock_bus(adapter, flags);
770 }
771
772 /**
773 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
774 * @adapter: Target I2C bus segment
775 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
776 * unlocks only this branch in the adapter tree
777 */
778 static inline void
779 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
780 {
781 adapter->lock_ops->unlock_bus(adapter, flags);
782 }
783
784 /**
785 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
786 * @adap: Adapter to mark as suspended
787 *
788 * When using this helper to mark an adapter as suspended, the core will reject
789 * further transfers to this adapter. The usage of this helper is optional but
790 * recommended for devices having distinct handlers for system suspend and
791 * runtime suspend. More complex devices are free to implement custom solutions
792 * to reject transfers when suspended.
793 */
794 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
795 {
796 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
797 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
798 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
799 }
800
801 /**
802 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
803 * @adap: Adapter to mark as resumed
804 *
805 * When using this helper to mark an adapter as resumed, the core will allow
806 * further transfers to this adapter. See also further notes to
807 * @i2c_mark_adapter_suspended().
808 */
809 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
810 {
811 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
812 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
813 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
814 }
815
816 /* i2c adapter classes (bitmask) */
817 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
818 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
819 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
820 /* Warn users that the adapter doesn't support classes anymore */
821 #define I2C_CLASS_DEPRECATED (1<<8)
822
823 /* Internal numbers to terminate lists */
824 #define I2C_CLIENT_END 0xfffeU
825
826 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
827 #define I2C_ADDRS(addr, addrs...) \
828 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
829
830
831 /* ----- functions exported by i2c.o */
832
833 /* administration...
834 */
835 #if IS_ENABLED(CONFIG_I2C)
836 extern int i2c_add_adapter(struct i2c_adapter *adap);
837 extern void i2c_del_adapter(struct i2c_adapter *adap);
838 extern int i2c_add_numbered_adapter(struct i2c_adapter *adap);
839
840 extern int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
841 extern void i2c_del_driver(struct i2c_driver *driver);
842
843 /* use a define to avoid include chaining to get THIS_MODULE */
844 #define i2c_add_driver(driver) \
845 i2c_register_driver(THIS_MODULE, driver)
846
847 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
848 extern void i2c_release_client(struct i2c_client *client);
849
850 /* call the i2c_client->command() of all attached clients with
851 * the given arguments */
852 extern void i2c_clients_command(struct i2c_adapter *adap,
853 unsigned int cmd, void *arg);
854
855 extern struct i2c_adapter *i2c_get_adapter(int nr);
856 extern void i2c_put_adapter(struct i2c_adapter *adap);
857 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
858
859 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
860
861 /* Return the functionality mask */
862 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
863 {
864 return adap->algo->functionality(adap);
865 }
866
867 /* Return 1 if adapter supports everything we need, 0 if not. */
868 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
869 {
870 return (func & i2c_get_functionality(adap)) == func;
871 }
872
873 /**
874 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
875 * @adap: i2c adapter
876 * @quirks: quirk flags
877 *
878 * Return: true if the adapter has all the specified quirk flags, false if not
879 */
880 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
881 {
882 if (!adap->quirks)
883 return false;
884 return (adap->quirks->flags & quirks) == quirks;
885 }
886
887 /* Return the adapter number for a specific adapter */
888 static inline int i2c_adapter_id(struct i2c_adapter *adap)
889 {
890 return adap->nr;
891 }
892
893 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
894 {
895 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
896 }
897
898 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
899 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
900
901 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
902 /**
903 * module_i2c_driver() - Helper macro for registering a modular I2C driver
904 * @__i2c_driver: i2c_driver struct
905 *
906 * Helper macro for I2C drivers which do not do anything special in module
907 * init/exit. This eliminates a lot of boilerplate. Each module may only
908 * use this macro once, and calling it replaces module_init() and module_exit()
909 */
910 #define module_i2c_driver(__i2c_driver) \
911 module_driver(__i2c_driver, i2c_add_driver, \
912 i2c_del_driver)
913
914 /**
915 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
916 * @__i2c_driver: i2c_driver struct
917 *
918 * Helper macro for I2C drivers which do not do anything special in their
919 * init. This eliminates a lot of boilerplate. Each driver may only
920 * use this macro once, and calling it replaces device_initcall().
921 */
922 #define builtin_i2c_driver(__i2c_driver) \
923 builtin_driver(__i2c_driver, i2c_add_driver)
924
925 #endif /* I2C */
926
927 #if IS_ENABLED(CONFIG_OF)
928 /* must call put_device() when done with returned i2c_client device */
929 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
930
931 /* must call put_device() when done with returned i2c_adapter device */
932 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
933
934 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
935 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
936
937 extern const struct of_device_id
938 *i2c_of_match_device(const struct of_device_id *matches,
939 struct i2c_client *client);
940
941 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
942 struct i2c_board_info *info);
943
944 #else
945
946 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
947 {
948 return NULL;
949 }
950
951 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
952 {
953 return NULL;
954 }
955
956 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
957 {
958 return NULL;
959 }
960
961 static inline const struct of_device_id
962 *i2c_of_match_device(const struct of_device_id *matches,
963 struct i2c_client *client)
964 {
965 return NULL;
966 }
967
968 static inline int of_i2c_get_board_info(struct device *dev,
969 struct device_node *node,
970 struct i2c_board_info *info)
971 {
972 return -ENOTSUPP;
973 }
974
975 #endif /* CONFIG_OF */
976
977 struct acpi_resource;
978 struct acpi_resource_i2c_serialbus;
979
980 #if IS_ENABLED(CONFIG_ACPI)
981 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
982 struct acpi_resource_i2c_serialbus **i2c);
983 u32 i2c_acpi_find_bus_speed(struct device *dev);
984 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
985 struct i2c_board_info *info);
986 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
987 #else
988 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
989 struct acpi_resource_i2c_serialbus **i2c)
990 {
991 return false;
992 }
993 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
994 {
995 return 0;
996 }
997 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
998 int index, struct i2c_board_info *info)
999 {
1000 return NULL;
1001 }
1002 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1003 {
1004 return NULL;
1005 }
1006 #endif /* CONFIG_ACPI */
1007
1008 #endif /* _LINUX_I2C_H */