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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 const struct bus_type i2c_bus_type;
27extern const struct device_type i2c_adapter_type;
28extern const struct device_type i2c_client_type;
29
30/* --- General options ------------------------------------------------ */
31
32struct i2c_msg;
33struct i2c_adapter;
34struct i2c_client;
35struct i2c_driver;
36struct i2c_device_identity;
37union i2c_smbus_data;
38struct i2c_board_info;
39enum i2c_slave_event;
40typedef 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
51struct module;
52struct property_entry;
53
54#if IS_ENABLED(CONFIG_I2C)
55/* Return the Frequency mode string based on the bus frequency */
56const 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 */
65int 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 */
76static 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 */
91static 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 */
106static inline int i2c_master_send(const struct i2c_client *client,
107 const char *buf, int count)
108{
109 return i2c_transfer_buffer_flags(client, buf: (char *)buf, count, flags: 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 */
121static 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, buf: (char *)buf, count,
125 I2C_M_DMA_SAFE);
126};
127
128/* Transfer num messages.
129 */
130int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
131/* Unlocked flavor */
132int __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. */
139s32 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 */
144s32 __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
151u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
152s32 i2c_smbus_read_byte(const struct i2c_client *client);
153s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
154s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
155s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
156 u8 command, u8 value);
157s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
158s32 i2c_smbus_write_word_data(const struct i2c_client *client,
159 u8 command, u16 value);
160
161static inline s32
162i2c_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
169static inline s32
170i2c_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 */
177s32 i2c_smbus_read_block_data(const struct i2c_client *client,
178 u8 command, u8 *values);
179s32 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 */
182s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
183 u8 command, u8 length, u8 *values);
184s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
185 u8 command, u8 length, const u8 *values);
186s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
187 u8 command, u8 length,
188 u8 *values);
189int i2c_get_device_id(const struct i2c_client *client,
190 struct i2c_device_identity *id);
191const 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 */
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
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 */
270struct i2c_driver {
271 unsigned int class;
272
273 /* Standard driver model interfaces */
274 int (*probe)(struct i2c_client *client);
275 void (*remove)(struct i2c_client *client);
276
277
278 /* driver model interfaces that don't relate to enumeration */
279 void (*shutdown)(struct i2c_client *client);
280
281 /* Alert callback, for example for the SMBus alert protocol.
282 * The format and meaning of the data value depends on the protocol.
283 * For the SMBus alert protocol, there is a single bit of data passed
284 * as the alert response's low bit ("event flag").
285 * For the SMBus Host Notify protocol, the data corresponds to the
286 * 16-bit payload data reported by the slave device acting as master.
287 */
288 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
289 unsigned int data);
290
291 /* a ioctl like command that can be used to perform specific functions
292 * with the device.
293 */
294 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
295
296 struct device_driver driver;
297 const struct i2c_device_id *id_table;
298
299 /* Device detection callback for automatic device creation */
300 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
301 const unsigned short *address_list;
302 struct list_head clients;
303
304 u32 flags;
305};
306#define to_i2c_driver(d) container_of_const(d, struct i2c_driver, driver)
307
308/**
309 * struct i2c_client - represent an I2C slave device
310 * @flags: see I2C_CLIENT_* for possible flags
311 * @addr: Address used on the I2C bus connected to the parent adapter.
312 * @name: Indicates the type of the device, usually a chip name that's
313 * generic enough to hide second-sourcing and compatible revisions.
314 * @adapter: manages the bus segment hosting this I2C device
315 * @dev: Driver model device node for the slave.
316 * @init_irq: IRQ that was set at initialization
317 * @irq: indicates the IRQ generated by this device (if any)
318 * @detected: member of an i2c_driver.clients list or i2c-core's
319 * userspace_devices list
320 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
321 * calls it to pass on slave events to the slave driver.
322 * @devres_group_id: id of the devres group that will be created for resources
323 * acquired when probing this device.
324 * @debugfs: pointer to the debugfs subdirectory which the I2C core created
325 * for this client.
326 *
327 * An i2c_client identifies a single device (i.e. chip) connected to an
328 * i2c bus. The behaviour exposed to Linux is defined by the driver
329 * managing the device.
330 */
331struct i2c_client {
332 unsigned short flags; /* div., see below */
333#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
334#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
335 /* Must equal I2C_M_TEN below */
336#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
337#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
338#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
339#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
340 /* Must match I2C_M_STOP|IGNORE_NAK */
341
342 unsigned short addr; /* chip address - NOTE: 7bit */
343 /* addresses are stored in the */
344 /* _LOWER_ 7 bits */
345 char name[I2C_NAME_SIZE];
346 struct i2c_adapter *adapter; /* the adapter we sit on */
347 struct device dev; /* the device structure */
348 int init_irq; /* irq set at initialization */
349 int irq; /* irq issued by device */
350 struct list_head detected;
351#if IS_ENABLED(CONFIG_I2C_SLAVE)
352 i2c_slave_cb_t slave_cb; /* callback for slave mode */
353#endif
354 void *devres_group_id; /* ID of probe devres group */
355 struct dentry *debugfs; /* per-client debugfs dir */
356};
357#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
358
359struct i2c_adapter *i2c_verify_adapter(struct device *dev);
360const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
361 const struct i2c_client *client);
362
363const void *i2c_get_match_data(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(dev: &client->dev);
374}
375
376static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
377{
378 dev_set_drvdata(dev: &client->dev, data);
379}
380
381/* I2C slave support */
382
383enum i2c_slave_event {
384 I2C_SLAVE_READ_REQUESTED,
385 I2C_SLAVE_WRITE_REQUESTED,
386 I2C_SLAVE_READ_PROCESSED,
387 I2C_SLAVE_WRITE_RECEIVED,
388 I2C_SLAVE_STOP,
389};
390
391int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
392int i2c_slave_unregister(struct i2c_client *client);
393int i2c_slave_event(struct i2c_client *client,
394 enum i2c_slave_event event, u8 *val);
395#if IS_ENABLED(CONFIG_I2C_SLAVE)
396bool i2c_detect_slave_mode(struct device *dev);
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 * @fwnode: device node supplied by the platform firmware
409 * @swnode: software node for the device
410 * @resources: resources associated with the device
411 * @num_resources: number of resources in the @resources array
412 * @irq: stored in i2c_client.irq
413 *
414 * I2C doesn't actually support hardware probing, although controllers and
415 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
416 * a device at a given address. Drivers commonly need more information than
417 * that, such as chip type, configuration, associated IRQ, and so on.
418 *
419 * i2c_board_info is used to build tables of information listing I2C devices
420 * that are present. This information is used to grow the driver model tree.
421 * For mainboards this is done statically using i2c_register_board_info();
422 * bus numbers identify adapters that aren't yet available. For add-on boards,
423 * i2c_new_client_device() does this dynamically with the adapter already known.
424 */
425struct i2c_board_info {
426 char type[I2C_NAME_SIZE];
427 unsigned short flags;
428 unsigned short addr;
429 const char *dev_name;
430 void *platform_data;
431 struct fwnode_handle *fwnode;
432 const struct software_node *swnode;
433 const struct resource *resources;
434 unsigned int num_resources;
435 int irq;
436};
437
438/**
439 * I2C_BOARD_INFO - macro used to list an i2c device and its address
440 * @dev_type: identifies the device type
441 * @dev_addr: the device's address on the bus.
442 *
443 * This macro initializes essential fields of a struct i2c_board_info,
444 * declaring what has been provided on a particular board. Optional
445 * fields (such as associated irq, or device-specific platform_data)
446 * are provided using conventional syntax.
447 */
448#define I2C_BOARD_INFO(dev_type, dev_addr) \
449 .type = dev_type, .addr = (dev_addr)
450
451
452#if IS_ENABLED(CONFIG_I2C)
453/*
454 * Add-on boards should register/unregister their devices; e.g. a board
455 * with integrated I2C, a config eeprom, sensors, and a codec that's
456 * used in conjunction with the primary hardware.
457 */
458struct i2c_client *
459i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
460
461/* If you don't know the exact address of an I2C device, use this variant
462 * instead, which can probe for device presence in a list of possible
463 * addresses. The "probe" callback function is optional. If it is provided,
464 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
465 * a default probing method is used.
466 */
467struct i2c_client *
468i2c_new_scanned_device(struct i2c_adapter *adap,
469 struct i2c_board_info *info,
470 unsigned short const *addr_list,
471 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
472
473/* Common custom probe functions */
474int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
475
476struct i2c_client *
477i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
478
479struct i2c_client *
480devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
481
482struct i2c_client *
483i2c_new_ancillary_device(struct i2c_client *client,
484 const char *name,
485 u16 default_addr);
486
487void i2c_unregister_device(struct i2c_client *client);
488
489struct i2c_client *i2c_verify_client(struct device *dev);
490#else
491static inline struct i2c_client *i2c_verify_client(struct device *dev)
492{
493 return NULL;
494}
495#endif /* I2C */
496
497/* Mainboard arch_initcall() code should register all its I2C devices.
498 * This is done at arch_initcall time, before declaring any i2c adapters.
499 * Modules for add-on boards must use other calls.
500 */
501#ifdef CONFIG_I2C_BOARDINFO
502int
503i2c_register_board_info(int busnum, struct i2c_board_info const *info,
504 unsigned n);
505#else
506static inline int
507i2c_register_board_info(int busnum, struct i2c_board_info const *info,
508 unsigned n)
509{
510 return 0;
511}
512#endif /* I2C_BOARDINFO */
513
514/**
515 * struct i2c_algorithm - represent I2C transfer methods
516 * @xfer: Transfer a given number of messages defined by the msgs array via
517 * the specified adapter.
518 * @xfer_atomic: Same as @xfer. Yet, only using atomic context so e.g. PMICs
519 * can be accessed very late before shutdown. Optional.
520 * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this
521 * is not present, then the bus layer will try and convert the SMBus calls
522 * into I2C transfers instead.
523 * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context
524 * so e.g. PMICs can be accessed very late before shutdown. Optional.
525 * @functionality: Return the flags that this algorithm/adapter pair supports
526 * from the ``I2C_FUNC_*`` flags.
527 * @reg_target: Register given client to local target mode of this adapter
528 * @unreg_target: Unregister given client from local target mode of this adapter
529 *
530 * @master_xfer: deprecated, use @xfer
531 * @master_xfer_atomic: deprecated, use @xfer_atomic
532 * @reg_slave: deprecated, use @reg_target
533 * @unreg_slave: deprecated, use @unreg_target
534 *
535 * i2c_algorithm is the interface to a class of hardware solutions which can
536 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
537 * to name two of the most common.
538 *
539 * The return codes from the ``xfer{_atomic}`` fields should indicate the
540 * type of error code that occurred during the transfer, as documented in the
541 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
542 * number of messages executed should be returned.
543 */
544struct i2c_algorithm {
545 /*
546 * If an adapter algorithm can't do I2C-level access, set xfer
547 * to NULL. If an adapter algorithm can do SMBus access, set
548 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
549 * using common I2C messages.
550 */
551 union {
552 int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
553 int num);
554 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
555 int num);
556 };
557 union {
558 int (*xfer_atomic)(struct i2c_adapter *adap,
559 struct i2c_msg *msgs, int num);
560 int (*master_xfer_atomic)(struct i2c_adapter *adap,
561 struct i2c_msg *msgs, int num);
562 };
563 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
564 unsigned short flags, char read_write,
565 u8 command, int size, union i2c_smbus_data *data);
566 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
567 unsigned short flags, char read_write,
568 u8 command, int size, union i2c_smbus_data *data);
569
570 /* To determine what the adapter supports */
571 u32 (*functionality)(struct i2c_adapter *adap);
572
573#if IS_ENABLED(CONFIG_I2C_SLAVE)
574 union {
575 int (*reg_target)(struct i2c_client *client);
576 int (*reg_slave)(struct i2c_client *client);
577 };
578 union {
579 int (*unreg_target)(struct i2c_client *client);
580 int (*unreg_slave)(struct i2c_client *client);
581 };
582#endif
583};
584
585/**
586 * struct i2c_lock_operations - represent I2C locking operations
587 * @lock_bus: Get exclusive access to an I2C bus segment
588 * @trylock_bus: Try to get exclusive access to an I2C bus segment
589 * @unlock_bus: Release exclusive access to an I2C bus segment
590 *
591 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
592 */
593struct i2c_lock_operations {
594 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
595 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
596 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
597};
598
599/**
600 * struct i2c_timings - I2C timing information
601 * @bus_freq_hz: the bus frequency in Hz
602 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
603 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
604 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
605 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
606 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
607 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
608 * digital filter can filter out
609 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
610 * analog filter
611 */
612struct i2c_timings {
613 u32 bus_freq_hz;
614 u32 scl_rise_ns;
615 u32 scl_fall_ns;
616 u32 scl_int_delay_ns;
617 u32 sda_fall_ns;
618 u32 sda_hold_ns;
619 u32 digital_filter_width_ns;
620 u32 analog_filter_cutoff_freq_hz;
621};
622
623/**
624 * struct i2c_bus_recovery_info - I2C bus recovery information
625 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
626 * i2c_generic_scl_recovery().
627 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
628 * recovery. Populated internally for generic GPIO recovery.
629 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
630 * Populated internally for generic GPIO recovery.
631 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
632 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
633 * GPIO, for generic GPIO recovery.
634 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
635 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
636 * for generic GPIO recovery.
637 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
638 * has a more complex internal logic than just reading SDA. Optional.
639 * @prepare_recovery: This will be called before starting recovery. Platform may
640 * configure padmux here for SDA/SCL line or something else they want.
641 * @unprepare_recovery: This will be called after completing recovery. Platform
642 * may configure padmux here for SDA/SCL line or something else they want.
643 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
644 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
645 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
646 * Optional.
647 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
648 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
649 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
650 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
651 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
652 * is called "gpio" or "recovery" and pinctrl is valid.
653 */
654struct i2c_bus_recovery_info {
655 int (*recover_bus)(struct i2c_adapter *adap);
656
657 int (*get_scl)(struct i2c_adapter *adap);
658 void (*set_scl)(struct i2c_adapter *adap, int val);
659 int (*get_sda)(struct i2c_adapter *adap);
660 void (*set_sda)(struct i2c_adapter *adap, int val);
661 int (*get_bus_free)(struct i2c_adapter *adap);
662
663 void (*prepare_recovery)(struct i2c_adapter *adap);
664 void (*unprepare_recovery)(struct i2c_adapter *adap);
665
666 /* gpio recovery */
667 struct gpio_desc *scl_gpiod;
668 struct gpio_desc *sda_gpiod;
669 struct pinctrl *pinctrl;
670 struct pinctrl_state *pins_default;
671 struct pinctrl_state *pins_gpio;
672};
673
674int i2c_recover_bus(struct i2c_adapter *adap);
675
676/* Generic recovery routines */
677int i2c_generic_scl_recovery(struct i2c_adapter *adap);
678
679/**
680 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
681 * @flags: see I2C_AQ_* for possible flags and read below
682 * @max_num_msgs: maximum number of messages per transfer
683 * @max_write_len: maximum length of a write message
684 * @max_read_len: maximum length of a read message
685 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
686 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
687 *
688 * Note about combined messages: Some I2C controllers can only send one message
689 * per transfer, plus something called combined message or write-then-read.
690 * This is (usually) a small write message followed by a read message and
691 * barely enough to access register based devices like EEPROMs. There is a flag
692 * to support this mode. It implies max_num_msg = 2 and does the length checks
693 * with max_comb_*_len because combined message mode usually has its own
694 * limitations. Because of HW implementations, some controllers can actually do
695 * write-then-anything or other variants. To support that, write-then-read has
696 * been broken out into smaller bits like write-first and read-second which can
697 * be combined as needed.
698 */
699
700struct i2c_adapter_quirks {
701 u64 flags;
702 int max_num_msgs;
703 u16 max_write_len;
704 u16 max_read_len;
705 u16 max_comb_1st_msg_len;
706 u16 max_comb_2nd_msg_len;
707};
708
709/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
710#define I2C_AQ_COMB BIT(0)
711/* first combined message must be write */
712#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
713/* second combined message must be read */
714#define I2C_AQ_COMB_READ_SECOND BIT(2)
715/* both combined messages must have the same target address */
716#define I2C_AQ_COMB_SAME_ADDR BIT(3)
717/* convenience macro for typical write-then read case */
718#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
719 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
720/* clock stretching is not supported */
721#define I2C_AQ_NO_CLK_STRETCH BIT(4)
722/* message cannot have length of 0 */
723#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
724#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
725#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
726/* adapter cannot do repeated START */
727#define I2C_AQ_NO_REP_START BIT(7)
728
729/*
730 * i2c_adapter is the structure used to identify a physical i2c bus along
731 * with the access algorithms necessary to access it.
732 */
733struct i2c_adapter {
734 struct module *owner;
735 unsigned int class; /* classes to allow probing for */
736 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
737 void *algo_data;
738
739 /* data fields that are valid for all devices */
740 const struct i2c_lock_operations *lock_ops;
741 struct rt_mutex bus_lock;
742 struct rt_mutex mux_lock;
743
744 int timeout; /* in jiffies */
745 int retries;
746 struct device dev; /* the adapter device */
747 unsigned long locked_flags; /* owned by the I2C core */
748#define I2C_ALF_IS_SUSPENDED 0
749#define I2C_ALF_SUSPEND_REPORTED 1
750
751 int nr;
752 char name[48];
753 struct completion dev_released;
754
755 struct mutex userspace_clients_lock;
756 struct list_head userspace_clients;
757
758 struct i2c_bus_recovery_info *bus_recovery_info;
759 const struct i2c_adapter_quirks *quirks;
760
761 struct irq_domain *host_notify_domain;
762 struct regulator *bus_regulator;
763
764 struct dentry *debugfs;
765
766 /* 7bit address space */
767 DECLARE_BITMAP(addrs_in_instantiation, 1 << 7);
768};
769#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
770
771static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
772{
773 return dev_get_drvdata(dev: &adap->dev);
774}
775
776static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
777{
778 dev_set_drvdata(dev: &adap->dev, data);
779}
780
781static inline struct i2c_adapter *
782i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
783{
784#if IS_ENABLED(CONFIG_I2C_MUX)
785 struct device *parent = adapter->dev.parent;
786
787 if (parent != NULL && parent->type == &i2c_adapter_type)
788 return to_i2c_adapter(parent);
789 else
790#endif
791 return NULL;
792}
793
794int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
795
796/* Adapter locking functions, exported for shared pin cases */
797#define I2C_LOCK_ROOT_ADAPTER BIT(0)
798#define I2C_LOCK_SEGMENT BIT(1)
799
800/**
801 * i2c_lock_bus - Get exclusive access to an I2C bus segment
802 * @adapter: Target I2C bus segment
803 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
804 * locks only this branch in the adapter tree
805 */
806static inline void
807i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
808{
809 adapter->lock_ops->lock_bus(adapter, flags);
810}
811
812/**
813 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
814 * @adapter: Target I2C bus segment
815 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
816 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
817 *
818 * Return: true if the I2C bus segment is locked, false otherwise
819 */
820static inline int
821i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
822{
823 return adapter->lock_ops->trylock_bus(adapter, flags);
824}
825
826/**
827 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
828 * @adapter: Target I2C bus segment
829 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
830 * unlocks only this branch in the adapter tree
831 */
832static inline void
833i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
834{
835 adapter->lock_ops->unlock_bus(adapter, flags);
836}
837
838/**
839 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
840 * @adap: Adapter to mark as suspended
841 *
842 * When using this helper to mark an adapter as suspended, the core will reject
843 * further transfers to this adapter. The usage of this helper is optional but
844 * recommended for devices having distinct handlers for system suspend and
845 * runtime suspend. More complex devices are free to implement custom solutions
846 * to reject transfers when suspended.
847 */
848static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
849{
850 i2c_lock_bus(adapter: adap, I2C_LOCK_ROOT_ADAPTER);
851 set_bit(I2C_ALF_IS_SUSPENDED, addr: &adap->locked_flags);
852 i2c_unlock_bus(adapter: adap, I2C_LOCK_ROOT_ADAPTER);
853}
854
855/**
856 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
857 * @adap: Adapter to mark as resumed
858 *
859 * When using this helper to mark an adapter as resumed, the core will allow
860 * further transfers to this adapter. See also further notes to
861 * @i2c_mark_adapter_suspended().
862 */
863static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
864{
865 i2c_lock_bus(adapter: adap, I2C_LOCK_ROOT_ADAPTER);
866 clear_bit(I2C_ALF_IS_SUSPENDED, addr: &adap->locked_flags);
867 i2c_unlock_bus(adapter: adap, I2C_LOCK_ROOT_ADAPTER);
868}
869
870/* i2c adapter classes (bitmask) */
871#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
872/* Warn users that the adapter doesn't support classes anymore */
873#define I2C_CLASS_DEPRECATED (1<<8)
874
875/* Internal numbers to terminate lists */
876#define I2C_CLIENT_END 0xfffeU
877
878/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
879#define I2C_ADDRS(addr, addrs...) \
880 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
881
882
883/* ----- functions exported by i2c.o */
884
885/* administration...
886 */
887#if IS_ENABLED(CONFIG_I2C)
888int i2c_add_adapter(struct i2c_adapter *adap);
889int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
890void i2c_del_adapter(struct i2c_adapter *adap);
891int i2c_add_numbered_adapter(struct i2c_adapter *adap);
892
893int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
894void i2c_del_driver(struct i2c_driver *driver);
895
896/* use a define to avoid include chaining to get THIS_MODULE */
897#define i2c_add_driver(driver) \
898 i2c_register_driver(THIS_MODULE, driver)
899
900static inline bool i2c_client_has_driver(struct i2c_client *client)
901{
902 return !IS_ERR_OR_NULL(ptr: client) && client->dev.driver;
903}
904
905/* call the i2c_client->command() of all attached clients with
906 * the given arguments */
907void i2c_clients_command(struct i2c_adapter *adap,
908 unsigned int cmd, void *arg);
909
910struct i2c_adapter *i2c_get_adapter(int nr);
911void i2c_put_adapter(struct i2c_adapter *adap);
912unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
913
914void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
915
916/* Return the functionality mask */
917static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
918{
919 return adap->algo->functionality(adap);
920}
921
922/* Return 1 if adapter supports everything we need, 0 if not. */
923static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
924{
925 return (func & i2c_get_functionality(adap)) == func;
926}
927
928/**
929 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
930 * @adap: i2c adapter
931 * @quirks: quirk flags
932 *
933 * Return: true if the adapter has all the specified quirk flags, false if not
934 */
935static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
936{
937 if (!adap->quirks)
938 return false;
939 return (adap->quirks->flags & quirks) == quirks;
940}
941
942/* Return the adapter number for a specific adapter */
943static inline int i2c_adapter_id(struct i2c_adapter *adap)
944{
945 return adap->nr;
946}
947
948static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
949{
950 return (msg->addr << 1) | (msg->flags & I2C_M_RD);
951}
952
953/*
954 * 10-bit address
955 * addr_1: 5'b11110 | addr[9:8] | (R/nW)
956 * addr_2: addr[7:0]
957 */
958static inline u8 i2c_10bit_addr_hi_from_msg(const struct i2c_msg *msg)
959{
960 return 0xf0 | ((msg->addr & GENMASK(9, 8)) >> 7) | (msg->flags & I2C_M_RD);
961}
962
963static inline u8 i2c_10bit_addr_lo_from_msg(const struct i2c_msg *msg)
964{
965 return msg->addr & GENMASK(7, 0);
966}
967
968u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
969void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
970
971int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
972/**
973 * module_i2c_driver() - Helper macro for registering a modular I2C driver
974 * @__i2c_driver: i2c_driver struct
975 *
976 * Helper macro for I2C drivers which do not do anything special in module
977 * init/exit. This eliminates a lot of boilerplate. Each module may only
978 * use this macro once, and calling it replaces module_init() and module_exit()
979 */
980#define module_i2c_driver(__i2c_driver) \
981 module_driver(__i2c_driver, i2c_add_driver, \
982 i2c_del_driver)
983
984/**
985 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
986 * @__i2c_driver: i2c_driver struct
987 *
988 * Helper macro for I2C drivers which do not do anything special in their
989 * init. This eliminates a lot of boilerplate. Each driver may only
990 * use this macro once, and calling it replaces device_initcall().
991 */
992#define builtin_i2c_driver(__i2c_driver) \
993 builtin_driver(__i2c_driver, i2c_add_driver)
994
995/* must call put_device() when done with returned i2c_client device */
996struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode);
997
998/* must call put_device() when done with returned i2c_adapter device */
999struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode);
1000
1001/* must call i2c_put_adapter() when done with returned i2c_adapter device */
1002struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode);
1003
1004#else /* I2C */
1005
1006static inline struct i2c_client *
1007i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
1008{
1009 return NULL;
1010}
1011
1012static inline struct i2c_adapter *
1013i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
1014{
1015 return NULL;
1016}
1017
1018static inline struct i2c_adapter *
1019i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)
1020{
1021 return NULL;
1022}
1023
1024#endif /* !I2C */
1025
1026#if IS_ENABLED(CONFIG_OF)
1027/* must call put_device() when done with returned i2c_client device */
1028static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1029{
1030 return i2c_find_device_by_fwnode(of_fwnode_handle(node));
1031}
1032
1033/* must call put_device() when done with returned i2c_adapter device */
1034static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1035{
1036 return i2c_find_adapter_by_fwnode(of_fwnode_handle(node));
1037}
1038
1039/* must call i2c_put_adapter() when done with returned i2c_adapter device */
1040static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1041{
1042 return i2c_get_adapter_by_fwnode(of_fwnode_handle(node));
1043}
1044
1045int of_i2c_get_board_info(struct device *dev, struct device_node *node,
1046 struct i2c_board_info *info);
1047
1048#else
1049
1050static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1051{
1052 return NULL;
1053}
1054
1055static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1056{
1057 return NULL;
1058}
1059
1060static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1061{
1062 return NULL;
1063}
1064
1065static inline int of_i2c_get_board_info(struct device *dev,
1066 struct device_node *node,
1067 struct i2c_board_info *info)
1068{
1069 return -ENOTSUPP;
1070}
1071
1072#endif /* CONFIG_OF */
1073
1074struct acpi_resource;
1075struct acpi_resource_i2c_serialbus;
1076
1077#if IS_REACHABLE(CONFIG_ACPI) && IS_REACHABLE(CONFIG_I2C)
1078bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1079 struct acpi_resource_i2c_serialbus **i2c);
1080int i2c_acpi_client_count(struct acpi_device *adev);
1081u32 i2c_acpi_find_bus_speed(struct device *dev);
1082struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1083 int index,
1084 struct i2c_board_info *info);
1085struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1086bool i2c_acpi_waive_d0_probe(struct device *dev);
1087#else
1088static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1089 struct acpi_resource_i2c_serialbus **i2c)
1090{
1091 return false;
1092}
1093static inline int i2c_acpi_client_count(struct acpi_device *adev)
1094{
1095 return 0;
1096}
1097static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1098{
1099 return 0;
1100}
1101static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1102 struct fwnode_handle *fwnode, int index,
1103 struct i2c_board_info *info)
1104{
1105 return ERR_PTR(-ENODEV);
1106}
1107static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1108{
1109 return NULL;
1110}
1111static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1112{
1113 return false;
1114}
1115#endif /* CONFIG_ACPI */
1116
1117static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1118 int index,
1119 struct i2c_board_info *info)
1120{
1121 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1122}
1123
1124#endif /* _LINUX_I2C_H */
1125

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