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
26extern struct bus_type i2c_bus_type;
27extern struct device_type i2c_adapter_type;
28extern struct device_type i2c_client_type;
29
30/* --- General options ------------------------------------------------ */
31
32struct i2c_msg;
33struct i2c_algorithm;
34struct i2c_adapter;
35struct i2c_client;
36struct i2c_driver;
37struct i2c_device_identity;
38union i2c_smbus_data;
39struct i2c_board_info;
40enum i2c_slave_event;
41typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
42 enum i2c_slave_event event, u8 *val);
43
44/* I2C Frequency Modes */
45#define I2C_MAX_STANDARD_MODE_FREQ 100000
46#define I2C_MAX_FAST_MODE_FREQ 400000
47#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
48#define I2C_MAX_TURBO_MODE_FREQ 1400000
49#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
50#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
51
52struct module;
53struct property_entry;
54
55#if IS_ENABLED(CONFIG_I2C)
56/* Return the Frequency mode string based on the bus frequency */
57const char *i2c_freq_mode_string(u32 bus_freq_hz);
58
59/*
60 * The master routines are the ones normally used to transmit data to devices
61 * on a bus (or read from them). Apart from two basic transfer functions to
62 * transmit one message at a time, a more complex version can be used to
63 * transmit an arbitrary number of messages without interruption.
64 * @count must be less than 64k since msg.len is u16.
65 */
66int i2c_transfer_buffer_flags(const struct i2c_client *client,
67 char *buf, int count, u16 flags);
68
69/**
70 * i2c_master_recv - issue a single I2C message in master receive mode
71 * @client: Handle to slave device
72 * @buf: Where to store data read from slave
73 * @count: How many bytes to read, must be less than 64k since msg.len is u16
74 *
75 * Returns negative errno, or else the number of bytes read.
76 */
77static inline int i2c_master_recv(const struct i2c_client *client,
78 char *buf, int count)
79{
80 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
81};
82
83/**
84 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
85 * using a DMA safe buffer
86 * @client: Handle to slave device
87 * @buf: Where to store data read from slave, must be safe to use with DMA
88 * @count: How many bytes to read, must be less than 64k since msg.len is u16
89 *
90 * Returns negative errno, or else the number of bytes read.
91 */
92static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
93 char *buf, int count)
94{
95 return i2c_transfer_buffer_flags(client, buf, count,
96 I2C_M_RD | I2C_M_DMA_SAFE);
97};
98
99/**
100 * i2c_master_send - issue a single I2C message in master transmit mode
101 * @client: Handle to slave device
102 * @buf: Data that will be written to the slave
103 * @count: How many bytes to write, must be less than 64k since msg.len is u16
104 *
105 * Returns negative errno, or else the number of bytes written.
106 */
107static inline int i2c_master_send(const struct i2c_client *client,
108 const char *buf, int count)
109{
110 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
111};
112
113/**
114 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
115 * using a DMA safe buffer
116 * @client: Handle to slave device
117 * @buf: Data that will be written to the slave, must be safe to use with DMA
118 * @count: How many bytes to write, must be less than 64k since msg.len is u16
119 *
120 * Returns negative errno, or else the number of bytes written.
121 */
122static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
123 const char *buf, int count)
124{
125 return i2c_transfer_buffer_flags(client, (char *)buf, count,
126 I2C_M_DMA_SAFE);
127};
128
129/* Transfer num messages.
130 */
131int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
132/* Unlocked flavor */
133int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
134
135/* This is the very generalized SMBus access routine. You probably do not
136 want to use this, though; one of the functions below may be much easier,
137 and probably just as fast.
138 Note that we use i2c_adapter here, because you do not need a specific
139 smbus adapter to call this function. */
140s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
141 unsigned short flags, char read_write, u8 command,
142 int protocol, union i2c_smbus_data *data);
143
144/* Unlocked flavor */
145s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
146 unsigned short flags, char read_write, u8 command,
147 int protocol, union i2c_smbus_data *data);
148
149/* Now follow the 'nice' access routines. These also document the calling
150 conventions of i2c_smbus_xfer. */
151
152u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
153s32 i2c_smbus_read_byte(const struct i2c_client *client);
154s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
155s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
156s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
157 u8 command, u8 value);
158s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
159s32 i2c_smbus_write_word_data(const struct i2c_client *client,
160 u8 command, u16 value);
161
162static inline s32
163i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
164{
165 s32 value = i2c_smbus_read_word_data(client, command);
166
167 return (value < 0) ? value : swab16(value);
168}
169
170static inline s32
171i2c_smbus_write_word_swapped(const struct i2c_client *client,
172 u8 command, u16 value)
173{
174 return i2c_smbus_write_word_data(client, command, swab16(value));
175}
176
177/* Returns the number of read bytes */
178s32 i2c_smbus_read_block_data(const struct i2c_client *client,
179 u8 command, u8 *values);
180s32 i2c_smbus_write_block_data(const struct i2c_client *client,
181 u8 command, u8 length, const u8 *values);
182/* Returns the number of read bytes */
183s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
184 u8 command, u8 length, u8 *values);
185s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
186 u8 command, u8 length, const u8 *values);
187s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
188 u8 command, u8 length,
189 u8 *values);
190int i2c_get_device_id(const struct i2c_client *client,
191 struct i2c_device_identity *id);
192#endif /* I2C */
193
194/**
195 * struct i2c_device_identity - i2c client device identification
196 * @manufacturer_id: 0 - 4095, database maintained by NXP
197 * @part_id: 0 - 511, according to manufacturer
198 * @die_revision: 0 - 7, according to manufacturer
199 */
200struct 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
221enum 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 */
231enum i2c_driver_flags {
232 I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0),
233};
234
235/**
236 * struct i2c_driver - represent an I2C device driver
237 * @class: What kind of i2c device we instantiate (for detect)
238 * @probe: Callback for device binding - soon to be deprecated
239 * @probe_new: New callback for device binding
240 * @remove: Callback for device unbinding
241 * @shutdown: Callback for device shutdown
242 * @alert: Alert callback, for example for the SMBus alert protocol
243 * @command: Callback for bus-wide signaling (optional)
244 * @driver: Device driver model driver
245 * @id_table: List of I2C devices supported by this driver
246 * @detect: Callback for device detection
247 * @address_list: The I2C addresses to probe (for detect)
248 * @clients: List of detected clients we created (for i2c-core use only)
249 * @flags: A bitmask of flags defined in &enum i2c_driver_flags
250 *
251 * The driver.owner field should be set to the module owner of this driver.
252 * The driver.name field should be set to the name of this driver.
253 *
254 * For automatic device detection, both @detect and @address_list must
255 * be defined. @class should also be set, otherwise only devices forced
256 * with module parameters will be created. The detect function must
257 * fill at least the name field of the i2c_board_info structure it is
258 * handed upon successful detection, and possibly also the flags field.
259 *
260 * If @detect is missing, the driver will still work fine for enumerated
261 * devices. Detected devices simply won't be supported. This is expected
262 * for the many I2C/SMBus devices which can't be detected reliably, and
263 * the ones which can always be enumerated in practice.
264 *
265 * The i2c_client structure which is handed to the @detect callback is
266 * not a real i2c_client. It is initialized just enough so that you can
267 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
268 * else with it. In particular, calling dev_dbg and friends on it is
269 * not allowed.
270 */
271struct i2c_driver {
272 unsigned int class;
273
274 /* Standard driver model interfaces */
275 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
276 int (*remove)(struct i2c_client *client);
277
278 /* New driver model interface to aid the seamless removal of the
279 * current probe()'s, more commonly unused than used second parameter.
280 */
281 int (*probe_new)(struct i2c_client *client);
282
283 /* driver model interfaces that don't relate to enumeration */
284 void (*shutdown)(struct i2c_client *client);
285
286 /* Alert callback, for example for the SMBus alert protocol.
287 * The format and meaning of the data value depends on the protocol.
288 * For the SMBus alert protocol, there is a single bit of data passed
289 * as the alert response's low bit ("event flag").
290 * For the SMBus Host Notify protocol, the data corresponds to the
291 * 16-bit payload data reported by the slave device acting as master.
292 */
293 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
294 unsigned int data);
295
296 /* a ioctl like command that can be used to perform specific functions
297 * with the device.
298 */
299 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
300
301 struct device_driver driver;
302 const struct i2c_device_id *id_table;
303
304 /* Device detection callback for automatic device creation */
305 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
306 const unsigned short *address_list;
307 struct list_head clients;
308
309 u32 flags;
310};
311#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
312
313/**
314 * struct i2c_client - represent an I2C slave device
315 * @flags: see I2C_CLIENT_* for possible flags
316 * @addr: Address used on the I2C bus connected to the parent adapter.
317 * @name: Indicates the type of the device, usually a chip name that's
318 * generic enough to hide second-sourcing and compatible revisions.
319 * @adapter: manages the bus segment hosting this I2C device
320 * @dev: Driver model device node for the slave.
321 * @init_irq: IRQ that was set at initialization
322 * @irq: indicates the IRQ generated by this device (if any)
323 * @detected: member of an i2c_driver.clients list or i2c-core's
324 * userspace_devices list
325 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
326 * calls it to pass on slave events to the slave driver.
327 * @devres_group_id: id of the devres group that will be created for resources
328 * acquired when probing this device.
329 *
330 * An i2c_client identifies a single device (i.e. chip) connected to an
331 * i2c bus. The behaviour exposed to Linux is defined by the driver
332 * managing the device.
333 */
334struct i2c_client {
335 unsigned short flags; /* div., see below */
336#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
337#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
338 /* Must equal I2C_M_TEN below */
339#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
340#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
341#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
342#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
343 /* Must match I2C_M_STOP|IGNORE_NAK */
344
345 unsigned short addr; /* chip address - NOTE: 7bit */
346 /* addresses are stored in the */
347 /* _LOWER_ 7 bits */
348 char name[I2C_NAME_SIZE];
349 struct i2c_adapter *adapter; /* the adapter we sit on */
350 struct device dev; /* the device structure */
351 int init_irq; /* irq set at initialization */
352 int irq; /* irq issued by device */
353 struct list_head detected;
354#if IS_ENABLED(CONFIG_I2C_SLAVE)
355 i2c_slave_cb_t slave_cb; /* callback for slave mode */
356#endif
357 void *devres_group_id; /* ID of probe devres group */
358};
359#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
360
361struct i2c_adapter *i2c_verify_adapter(struct device *dev);
362const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
363 const struct i2c_client *client);
364
365static 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
371static inline void *i2c_get_clientdata(const struct i2c_client *client)
372{
373 return dev_get_drvdata(&client->dev);
374}
375
376static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
377{
378 dev_set_drvdata(&client->dev, data);
379}
380
381/* I2C slave support */
382
383#if IS_ENABLED(CONFIG_I2C_SLAVE)
384enum i2c_slave_event {
385 I2C_SLAVE_READ_REQUESTED,
386 I2C_SLAVE_WRITE_REQUESTED,
387 I2C_SLAVE_READ_PROCESSED,
388 I2C_SLAVE_WRITE_RECEIVED,
389 I2C_SLAVE_STOP,
390};
391
392int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
393int i2c_slave_unregister(struct i2c_client *client);
394bool i2c_detect_slave_mode(struct device *dev);
395int i2c_slave_event(struct i2c_client *client,
396 enum i2c_slave_event event, u8 *val);
397#else
398static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
399#endif
400
401/**
402 * struct i2c_board_info - template for device creation
403 * @type: chip type, to initialize i2c_client.name
404 * @flags: to initialize i2c_client.flags
405 * @addr: stored in i2c_client.addr
406 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
407 * @platform_data: stored in i2c_client.dev.platform_data
408 * @of_node: pointer to OpenFirmware device node
409 * @fwnode: device node supplied by the platform firmware
410 * @swnode: software node for the device
411 * @resources: resources associated with the device
412 * @num_resources: number of resources in the @resources array
413 * @irq: stored in i2c_client.irq
414 *
415 * I2C doesn't actually support hardware probing, although controllers and
416 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
417 * a device at a given address. Drivers commonly need more information than
418 * that, such as chip type, configuration, associated IRQ, and so on.
419 *
420 * i2c_board_info is used to build tables of information listing I2C devices
421 * that are present. This information is used to grow the driver model tree.
422 * For mainboards this is done statically using i2c_register_board_info();
423 * bus numbers identify adapters that aren't yet available. For add-on boards,
424 * i2c_new_client_device() does this dynamically with the adapter already known.
425 */
426struct i2c_board_info {
427 char type[I2C_NAME_SIZE];
428 unsigned short flags;
429 unsigned short addr;
430 const char *dev_name;
431 void *platform_data;
432 struct device_node *of_node;
433 struct fwnode_handle *fwnode;
434 const struct software_node *swnode;
435 const struct resource *resources;
436 unsigned int num_resources;
437 int irq;
438};
439
440/**
441 * I2C_BOARD_INFO - macro used to list an i2c device and its address
442 * @dev_type: identifies the device type
443 * @dev_addr: the device's address on the bus.
444 *
445 * This macro initializes essential fields of a struct i2c_board_info,
446 * declaring what has been provided on a particular board. Optional
447 * fields (such as associated irq, or device-specific platform_data)
448 * are provided using conventional syntax.
449 */
450#define I2C_BOARD_INFO(dev_type, dev_addr) \
451 .type = dev_type, .addr = (dev_addr)
452
453
454#if IS_ENABLED(CONFIG_I2C)
455/*
456 * Add-on boards should register/unregister their devices; e.g. a board
457 * with integrated I2C, a config eeprom, sensors, and a codec that's
458 * used in conjunction with the primary hardware.
459 */
460struct i2c_client *
461i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
462
463/* If you don't know the exact address of an I2C device, use this variant
464 * instead, which can probe for device presence in a list of possible
465 * addresses. The "probe" callback function is optional. If it is provided,
466 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
467 * a default probing method is used.
468 */
469struct i2c_client *
470i2c_new_scanned_device(struct i2c_adapter *adap,
471 struct i2c_board_info *info,
472 unsigned short const *addr_list,
473 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
474
475/* Common custom probe functions */
476int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
477
478struct i2c_client *
479i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
480
481struct i2c_client *
482devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
483
484struct i2c_client *
485i2c_new_ancillary_device(struct i2c_client *client,
486 const char *name,
487 u16 default_addr);
488
489void i2c_unregister_device(struct i2c_client *client);
490
491struct i2c_client *i2c_verify_client(struct device *dev);
492#else
493static inline struct i2c_client *i2c_verify_client(struct device *dev)
494{
495 return NULL;
496}
497#endif /* I2C */
498
499/* Mainboard arch_initcall() code should register all its I2C devices.
500 * This is done at arch_initcall time, before declaring any i2c adapters.
501 * Modules for add-on boards must use other calls.
502 */
503#ifdef CONFIG_I2C_BOARDINFO
504int
505i2c_register_board_info(int busnum, struct i2c_board_info const *info,
506 unsigned n);
507#else
508static inline int
509i2c_register_board_info(int busnum, struct i2c_board_info const *info,
510 unsigned n)
511{
512 return 0;
513}
514#endif /* I2C_BOARDINFO */
515
516/**
517 * struct i2c_algorithm - represent I2C transfer method
518 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
519 * defined by the msgs array, with num messages available to transfer via
520 * the adapter specified by adap.
521 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
522 * so e.g. PMICs can be accessed very late before shutdown. Optional.
523 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
524 * is not present, then the bus layer will try and convert the SMBus calls
525 * into I2C transfers instead.
526 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
527 * so e.g. PMICs can be accessed very late before shutdown. Optional.
528 * @functionality: Return the flags that this algorithm/adapter pair supports
529 * from the ``I2C_FUNC_*`` flags.
530 * @reg_slave: Register given client to I2C slave mode of this adapter
531 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
532 *
533 * The following structs are for those who like to implement new bus drivers:
534 * i2c_algorithm is the interface to a class of hardware solutions which can
535 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
536 * to name two of the most common.
537 *
538 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
539 * type of error code that occurred during the transfer, as documented in the
540 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
541 * number of messages executed should be returned.
542 */
543struct i2c_algorithm {
544 /*
545 * If an adapter algorithm can't do I2C-level access, set master_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 * master_xfer should return the number of messages successfully
551 * processed, or a negative value on error
552 */
553 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
554 int num);
555 int (*master_xfer_atomic)(struct i2c_adapter *adap,
556 struct i2c_msg *msgs, int num);
557 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
558 unsigned short flags, char read_write,
559 u8 command, int size, union i2c_smbus_data *data);
560 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
561 unsigned short flags, char read_write,
562 u8 command, int size, union i2c_smbus_data *data);
563
564 /* To determine what the adapter supports */
565 u32 (*functionality)(struct i2c_adapter *adap);
566
567#if IS_ENABLED(CONFIG_I2C_SLAVE)
568 int (*reg_slave)(struct i2c_client *client);
569 int (*unreg_slave)(struct i2c_client *client);
570#endif
571};
572
573/**
574 * struct i2c_lock_operations - represent I2C locking operations
575 * @lock_bus: Get exclusive access to an I2C bus segment
576 * @trylock_bus: Try to get exclusive access to an I2C bus segment
577 * @unlock_bus: Release exclusive access to an I2C bus segment
578 *
579 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
580 */
581struct i2c_lock_operations {
582 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
583 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
584 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
585};
586
587/**
588 * struct i2c_timings - I2C timing information
589 * @bus_freq_hz: the bus frequency in Hz
590 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
591 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
592 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
593 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
594 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
595 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
596 * digital filter can filter out
597 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
598 * analog filter
599 */
600struct i2c_timings {
601 u32 bus_freq_hz;
602 u32 scl_rise_ns;
603 u32 scl_fall_ns;
604 u32 scl_int_delay_ns;
605 u32 sda_fall_ns;
606 u32 sda_hold_ns;
607 u32 digital_filter_width_ns;
608 u32 analog_filter_cutoff_freq_hz;
609};
610
611/**
612 * struct i2c_bus_recovery_info - I2C bus recovery information
613 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
614 * i2c_generic_scl_recovery().
615 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
616 * recovery. Populated internally for generic GPIO recovery.
617 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
618 * Populated internally for generic GPIO recovery.
619 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
620 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
621 * GPIO, for generic GPIO recovery.
622 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
623 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
624 * for generic GPIO recovery.
625 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
626 * has a more complex internal logic than just reading SDA. Optional.
627 * @prepare_recovery: This will be called before starting recovery. Platform may
628 * configure padmux here for SDA/SCL line or something else they want.
629 * @unprepare_recovery: This will be called after completing recovery. Platform
630 * may configure padmux here for SDA/SCL line or something else they want.
631 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
632 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
633 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
634 * Optional.
635 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
636 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
637 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
638 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
639 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
640 * is called "gpio" or "recovery" and pinctrl is valid.
641 */
642struct i2c_bus_recovery_info {
643 int (*recover_bus)(struct i2c_adapter *adap);
644
645 int (*get_scl)(struct i2c_adapter *adap);
646 void (*set_scl)(struct i2c_adapter *adap, int val);
647 int (*get_sda)(struct i2c_adapter *adap);
648 void (*set_sda)(struct i2c_adapter *adap, int val);
649 int (*get_bus_free)(struct i2c_adapter *adap);
650
651 void (*prepare_recovery)(struct i2c_adapter *adap);
652 void (*unprepare_recovery)(struct i2c_adapter *adap);
653
654 /* gpio recovery */
655 struct gpio_desc *scl_gpiod;
656 struct gpio_desc *sda_gpiod;
657 struct pinctrl *pinctrl;
658 struct pinctrl_state *pins_default;
659 struct pinctrl_state *pins_gpio;
660};
661
662int i2c_recover_bus(struct i2c_adapter *adap);
663
664/* Generic recovery routines */
665int i2c_generic_scl_recovery(struct i2c_adapter *adap);
666
667/**
668 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
669 * @flags: see I2C_AQ_* for possible flags and read below
670 * @max_num_msgs: maximum number of messages per transfer
671 * @max_write_len: maximum length of a write message
672 * @max_read_len: maximum length of a read message
673 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
674 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
675 *
676 * Note about combined messages: Some I2C controllers can only send one message
677 * per transfer, plus something called combined message or write-then-read.
678 * This is (usually) a small write message followed by a read message and
679 * barely enough to access register based devices like EEPROMs. There is a flag
680 * to support this mode. It implies max_num_msg = 2 and does the length checks
681 * with max_comb_*_len because combined message mode usually has its own
682 * limitations. Because of HW implementations, some controllers can actually do
683 * write-then-anything or other variants. To support that, write-then-read has
684 * been broken out into smaller bits like write-first and read-second which can
685 * be combined as needed.
686 */
687
688struct i2c_adapter_quirks {
689 u64 flags;
690 int max_num_msgs;
691 u16 max_write_len;
692 u16 max_read_len;
693 u16 max_comb_1st_msg_len;
694 u16 max_comb_2nd_msg_len;
695};
696
697/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
698#define I2C_AQ_COMB BIT(0)
699/* first combined message must be write */
700#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
701/* second combined message must be read */
702#define I2C_AQ_COMB_READ_SECOND BIT(2)
703/* both combined messages must have the same target address */
704#define I2C_AQ_COMB_SAME_ADDR BIT(3)
705/* convenience macro for typical write-then read case */
706#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
707 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
708/* clock stretching is not supported */
709#define I2C_AQ_NO_CLK_STRETCH BIT(4)
710/* message cannot have length of 0 */
711#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
712#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
713#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
714/* adapter cannot do repeated START */
715#define I2C_AQ_NO_REP_START BIT(7)
716
717/*
718 * i2c_adapter is the structure used to identify a physical i2c bus along
719 * with the access algorithms necessary to access it.
720 */
721struct i2c_adapter {
722 struct module *owner;
723 unsigned int class; /* classes to allow probing for */
724 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
725 void *algo_data;
726
727 /* data fields that are valid for all devices */
728 const struct i2c_lock_operations *lock_ops;
729 struct rt_mutex bus_lock;
730 struct rt_mutex mux_lock;
731
732 int timeout; /* in jiffies */
733 int retries;
734 struct device dev; /* the adapter device */
735 unsigned long locked_flags; /* owned by the I2C core */
736#define I2C_ALF_IS_SUSPENDED 0
737#define I2C_ALF_SUSPEND_REPORTED 1
738
739 int nr;
740 char name[48];
741 struct completion dev_released;
742
743 struct mutex userspace_clients_lock;
744 struct list_head userspace_clients;
745
746 struct i2c_bus_recovery_info *bus_recovery_info;
747 const struct i2c_adapter_quirks *quirks;
748
749 struct irq_domain *host_notify_domain;
750 struct regulator *bus_regulator;
751};
752#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
753
754static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
755{
756 return dev_get_drvdata(&adap->dev);
757}
758
759static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
760{
761 dev_set_drvdata(&adap->dev, data);
762}
763
764static inline struct i2c_adapter *
765i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
766{
767#if IS_ENABLED(CONFIG_I2C_MUX)
768 struct device *parent = adapter->dev.parent;
769
770 if (parent != NULL && parent->type == &i2c_adapter_type)
771 return to_i2c_adapter(parent);
772 else
773#endif
774 return NULL;
775}
776
777int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
778
779/* Adapter locking functions, exported for shared pin cases */
780#define I2C_LOCK_ROOT_ADAPTER BIT(0)
781#define I2C_LOCK_SEGMENT BIT(1)
782
783/**
784 * i2c_lock_bus - Get exclusive access to an I2C bus segment
785 * @adapter: Target I2C bus segment
786 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
787 * locks only this branch in the adapter tree
788 */
789static inline void
790i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
791{
792 adapter->lock_ops->lock_bus(adapter, flags);
793}
794
795/**
796 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
797 * @adapter: Target I2C bus segment
798 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
799 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
800 *
801 * Return: true if the I2C bus segment is locked, false otherwise
802 */
803static inline int
804i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
805{
806 return adapter->lock_ops->trylock_bus(adapter, flags);
807}
808
809/**
810 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
811 * @adapter: Target I2C bus segment
812 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
813 * unlocks only this branch in the adapter tree
814 */
815static inline void
816i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
817{
818 adapter->lock_ops->unlock_bus(adapter, flags);
819}
820
821/**
822 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
823 * @adap: Adapter to mark as suspended
824 *
825 * When using this helper to mark an adapter as suspended, the core will reject
826 * further transfers to this adapter. The usage of this helper is optional but
827 * recommended for devices having distinct handlers for system suspend and
828 * runtime suspend. More complex devices are free to implement custom solutions
829 * to reject transfers when suspended.
830 */
831static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
832{
833 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
834 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
835 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
836}
837
838/**
839 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
840 * @adap: Adapter to mark as resumed
841 *
842 * When using this helper to mark an adapter as resumed, the core will allow
843 * further transfers to this adapter. See also further notes to
844 * @i2c_mark_adapter_suspended().
845 */
846static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
847{
848 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
849 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
850 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
851}
852
853/* i2c adapter classes (bitmask) */
854#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
855#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
856#define I2C_CLASS_SPD (1<<7) /* Memory modules */
857/* Warn users that the adapter doesn't support classes anymore */
858#define I2C_CLASS_DEPRECATED (1<<8)
859
860/* Internal numbers to terminate lists */
861#define I2C_CLIENT_END 0xfffeU
862
863/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
864#define I2C_ADDRS(addr, addrs...) \
865 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
866
867
868/* ----- functions exported by i2c.o */
869
870/* administration...
871 */
872#if IS_ENABLED(CONFIG_I2C)
873int i2c_add_adapter(struct i2c_adapter *adap);
874int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
875void i2c_del_adapter(struct i2c_adapter *adap);
876int i2c_add_numbered_adapter(struct i2c_adapter *adap);
877
878int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
879void i2c_del_driver(struct i2c_driver *driver);
880
881/* use a define to avoid include chaining to get THIS_MODULE */
882#define i2c_add_driver(driver) \
883 i2c_register_driver(THIS_MODULE, driver)
884
885static inline bool i2c_client_has_driver(struct i2c_client *client)
886{
887 return !IS_ERR_OR_NULL(client) && client->dev.driver;
888}
889
890/* call the i2c_client->command() of all attached clients with
891 * the given arguments */
892void i2c_clients_command(struct i2c_adapter *adap,
893 unsigned int cmd, void *arg);
894
895struct i2c_adapter *i2c_get_adapter(int nr);
896void i2c_put_adapter(struct i2c_adapter *adap);
897unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
898
899void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
900
901/* Return the functionality mask */
902static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
903{
904 return adap->algo->functionality(adap);
905}
906
907/* Return 1 if adapter supports everything we need, 0 if not. */
908static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
909{
910 return (func & i2c_get_functionality(adap)) == func;
911}
912
913/**
914 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
915 * @adap: i2c adapter
916 * @quirks: quirk flags
917 *
918 * Return: true if the adapter has all the specified quirk flags, false if not
919 */
920static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
921{
922 if (!adap->quirks)
923 return false;
924 return (adap->quirks->flags & quirks) == quirks;
925}
926
927/* Return the adapter number for a specific adapter */
928static inline int i2c_adapter_id(struct i2c_adapter *adap)
929{
930 return adap->nr;
931}
932
933static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
934{
935 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
936}
937
938u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
939void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
940
941int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
942/**
943 * module_i2c_driver() - Helper macro for registering a modular I2C driver
944 * @__i2c_driver: i2c_driver struct
945 *
946 * Helper macro for I2C drivers which do not do anything special in module
947 * init/exit. This eliminates a lot of boilerplate. Each module may only
948 * use this macro once, and calling it replaces module_init() and module_exit()
949 */
950#define module_i2c_driver(__i2c_driver) \
951 module_driver(__i2c_driver, i2c_add_driver, \
952 i2c_del_driver)
953
954/**
955 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
956 * @__i2c_driver: i2c_driver struct
957 *
958 * Helper macro for I2C drivers which do not do anything special in their
959 * init. This eliminates a lot of boilerplate. Each driver may only
960 * use this macro once, and calling it replaces device_initcall().
961 */
962#define builtin_i2c_driver(__i2c_driver) \
963 builtin_driver(__i2c_driver, i2c_add_driver)
964
965#endif /* I2C */
966
967#if IS_ENABLED(CONFIG_OF)
968/* must call put_device() when done with returned i2c_client device */
969struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
970
971/* must call put_device() when done with returned i2c_adapter device */
972struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
973
974/* must call i2c_put_adapter() when done with returned i2c_adapter device */
975struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
976
977const struct of_device_id
978*i2c_of_match_device(const struct of_device_id *matches,
979 struct i2c_client *client);
980
981int of_i2c_get_board_info(struct device *dev, struct device_node *node,
982 struct i2c_board_info *info);
983
984#else
985
986static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
987{
988 return NULL;
989}
990
991static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
992{
993 return NULL;
994}
995
996static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
997{
998 return NULL;
999}
1000
1001static inline const struct of_device_id
1002*i2c_of_match_device(const struct of_device_id *matches,
1003 struct i2c_client *client)
1004{
1005 return NULL;
1006}
1007
1008static inline int of_i2c_get_board_info(struct device *dev,
1009 struct device_node *node,
1010 struct i2c_board_info *info)
1011{
1012 return -ENOTSUPP;
1013}
1014
1015#endif /* CONFIG_OF */
1016
1017struct acpi_resource;
1018struct acpi_resource_i2c_serialbus;
1019
1020#if IS_ENABLED(CONFIG_ACPI)
1021bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1022 struct acpi_resource_i2c_serialbus **i2c);
1023int i2c_acpi_client_count(struct acpi_device *adev);
1024u32 i2c_acpi_find_bus_speed(struct device *dev);
1025struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1026 int index,
1027 struct i2c_board_info *info);
1028struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1029bool i2c_acpi_waive_d0_probe(struct device *dev);
1030#else
1031static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1032 struct acpi_resource_i2c_serialbus **i2c)
1033{
1034 return false;
1035}
1036static inline int i2c_acpi_client_count(struct acpi_device *adev)
1037{
1038 return 0;
1039}
1040static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1041{
1042 return 0;
1043}
1044static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1045 struct fwnode_handle *fwnode, int index,
1046 struct i2c_board_info *info)
1047{
1048 return ERR_PTR(-ENODEV);
1049}
1050static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1051{
1052 return NULL;
1053}
1054static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1055{
1056 return false;
1057}
1058#endif /* CONFIG_ACPI */
1059
1060static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1061 int index,
1062 struct i2c_board_info *info)
1063{
1064 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1065}
1066
1067#endif /* _LINUX_I2C_H */
1068

source code of linux/include/linux/i2c.h