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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/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
24extern struct bus_type i2c_bus_type;
25extern struct device_type i2c_adapter_type;
26extern struct device_type i2c_client_type;
27
28/* --- General options ------------------------------------------------ */
29
30struct i2c_msg;
31struct i2c_algorithm;
32struct i2c_adapter;
33struct i2c_client;
34struct i2c_driver;
35struct i2c_device_identity;
36union i2c_smbus_data;
37struct i2c_board_info;
38enum i2c_slave_event;
39typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
40 enum i2c_slave_event event, u8 *val);
41
42/* I2C Frequency Modes */
43#define I2C_MAX_STANDARD_MODE_FREQ 100000
44#define I2C_MAX_FAST_MODE_FREQ 400000
45#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
46#define I2C_MAX_TURBO_MODE_FREQ 1400000
47#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
48#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
49
50struct module;
51struct property_entry;
52
53#if IS_ENABLED(CONFIG_I2C)
54/*
55 * The master routines are the ones normally used to transmit data to devices
56 * on a bus (or read from them). Apart from two basic transfer functions to
57 * transmit one message at a time, a more complex version can be used to
58 * transmit an arbitrary number of messages without interruption.
59 * @count must be less than 64k since msg.len is u16.
60 */
61int i2c_transfer_buffer_flags(const struct i2c_client *client,
62 char *buf, int count, u16 flags);
63
64/**
65 * i2c_master_recv - issue a single I2C message in master receive mode
66 * @client: Handle to slave device
67 * @buf: Where to store data read from slave
68 * @count: How many bytes to read, must be less than 64k since msg.len is u16
69 *
70 * Returns negative errno, or else the number of bytes read.
71 */
72static inline int i2c_master_recv(const struct i2c_client *client,
73 char *buf, int count)
74{
75 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
76};
77
78/**
79 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
80 * using a DMA safe buffer
81 * @client: Handle to slave device
82 * @buf: Where to store data read from slave, must be safe to use with DMA
83 * @count: How many bytes to read, must be less than 64k since msg.len is u16
84 *
85 * Returns negative errno, or else the number of bytes read.
86 */
87static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
88 char *buf, int count)
89{
90 return i2c_transfer_buffer_flags(client, buf, count,
91 I2C_M_RD | I2C_M_DMA_SAFE);
92};
93
94/**
95 * i2c_master_send - issue a single I2C message in master transmit mode
96 * @client: Handle to slave device
97 * @buf: Data that will be written to the slave
98 * @count: How many bytes to write, must be less than 64k since msg.len is u16
99 *
100 * Returns negative errno, or else the number of bytes written.
101 */
102static inline int i2c_master_send(const struct i2c_client *client,
103 const char *buf, int count)
104{
105 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
106};
107
108/**
109 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
110 * using a DMA safe buffer
111 * @client: Handle to slave device
112 * @buf: Data that will be written to the slave, must be safe to use with DMA
113 * @count: How many bytes to write, must be less than 64k since msg.len is u16
114 *
115 * Returns negative errno, or else the number of bytes written.
116 */
117static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
118 const char *buf, int count)
119{
120 return i2c_transfer_buffer_flags(client, (char *)buf, count,
121 I2C_M_DMA_SAFE);
122};
123
124/* Transfer num messages.
125 */
126int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
127/* Unlocked flavor */
128int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
129
130/* This is the very generalized SMBus access routine. You probably do not
131 want to use this, though; one of the functions below may be much easier,
132 and probably just as fast.
133 Note that we use i2c_adapter here, because you do not need a specific
134 smbus adapter to call this function. */
135s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
136 unsigned short flags, char read_write, u8 command,
137 int protocol, union i2c_smbus_data *data);
138
139/* Unlocked flavor */
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/* Now follow the 'nice' access routines. These also document the calling
145 conventions of i2c_smbus_xfer. */
146
147s32 i2c_smbus_read_byte(const struct i2c_client *client);
148s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
149s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
150s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
151 u8 command, u8 value);
152s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
153s32 i2c_smbus_write_word_data(const struct i2c_client *client,
154 u8 command, u16 value);
155
156static inline s32
157i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
158{
159 s32 value = i2c_smbus_read_word_data(client, command);
160
161 return (value < 0) ? value : swab16(value);
162}
163
164static inline s32
165i2c_smbus_write_word_swapped(const struct i2c_client *client,
166 u8 command, u16 value)
167{
168 return i2c_smbus_write_word_data(client, command, swab16(value));
169}
170
171/* Returns the number of read bytes */
172s32 i2c_smbus_read_block_data(const struct i2c_client *client,
173 u8 command, u8 *values);
174s32 i2c_smbus_write_block_data(const struct i2c_client *client,
175 u8 command, u8 length, const u8 *values);
176/* Returns the number of read bytes */
177s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
178 u8 command, u8 length, u8 *values);
179s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
180 u8 command, u8 length, const u8 *values);
181s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
182 u8 command, u8 length,
183 u8 *values);
184int i2c_get_device_id(const struct i2c_client *client,
185 struct i2c_device_identity *id);
186#endif /* I2C */
187
188/**
189 * struct i2c_device_identity - i2c client device identification
190 * @manufacturer_id: 0 - 4095, database maintained by NXP
191 * @part_id: 0 - 511, according to manufacturer
192 * @die_revision: 0 - 7, according to manufacturer
193 */
194struct i2c_device_identity {
195 u16 manufacturer_id;
196#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
197#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
198#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
199#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
200#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
201#define I2C_DEVICE_ID_ANALOG_DEVICES 5
202#define I2C_DEVICE_ID_STMICROELECTRONICS 6
203#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
204#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
205#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
206#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
207#define I2C_DEVICE_ID_FLIR 11
208#define I2C_DEVICE_ID_O2MICRO 12
209#define I2C_DEVICE_ID_ATMEL 13
210#define I2C_DEVICE_ID_NONE 0xffff
211 u16 part_id;
212 u8 die_revision;
213};
214
215enum i2c_alert_protocol {
216 I2C_PROTOCOL_SMBUS_ALERT,
217 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
218};
219
220/**
221 * struct i2c_driver - represent an I2C device driver
222 * @class: What kind of i2c device we instantiate (for detect)
223 * @probe: Callback for device binding - soon to be deprecated
224 * @probe_new: New callback for device binding
225 * @remove: Callback for device unbinding
226 * @shutdown: Callback for device shutdown
227 * @alert: Alert callback, for example for the SMBus alert protocol
228 * @command: Callback for bus-wide signaling (optional)
229 * @driver: Device driver model driver
230 * @id_table: List of I2C devices supported by this driver
231 * @detect: Callback for device detection
232 * @address_list: The I2C addresses to probe (for detect)
233 * @clients: List of detected clients we created (for i2c-core use only)
234 *
235 * The driver.owner field should be set to the module owner of this driver.
236 * The driver.name field should be set to the name of this driver.
237 *
238 * For automatic device detection, both @detect and @address_list must
239 * be defined. @class should also be set, otherwise only devices forced
240 * with module parameters will be created. The detect function must
241 * fill at least the name field of the i2c_board_info structure it is
242 * handed upon successful detection, and possibly also the flags field.
243 *
244 * If @detect is missing, the driver will still work fine for enumerated
245 * devices. Detected devices simply won't be supported. This is expected
246 * for the many I2C/SMBus devices which can't be detected reliably, and
247 * the ones which can always be enumerated in practice.
248 *
249 * The i2c_client structure which is handed to the @detect callback is
250 * not a real i2c_client. It is initialized just enough so that you can
251 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
252 * else with it. In particular, calling dev_dbg and friends on it is
253 * not allowed.
254 */
255struct i2c_driver {
256 unsigned int class;
257
258 /* Standard driver model interfaces */
259 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
260 int (*remove)(struct i2c_client *client);
261
262 /* New driver model interface to aid the seamless removal of the
263 * current probe()'s, more commonly unused than used second parameter.
264 */
265 int (*probe_new)(struct i2c_client *client);
266
267 /* driver model interfaces that don't relate to enumeration */
268 void (*shutdown)(struct i2c_client *client);
269
270 /* Alert callback, for example for the SMBus alert protocol.
271 * The format and meaning of the data value depends on the protocol.
272 * For the SMBus alert protocol, there is a single bit of data passed
273 * as the alert response's low bit ("event flag").
274 * For the SMBus Host Notify protocol, the data corresponds to the
275 * 16-bit payload data reported by the slave device acting as master.
276 */
277 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
278 unsigned int data);
279
280 /* a ioctl like command that can be used to perform specific functions
281 * with the device.
282 */
283 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
284
285 struct device_driver driver;
286 const struct i2c_device_id *id_table;
287
288 /* Device detection callback for automatic device creation */
289 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
290 const unsigned short *address_list;
291 struct list_head clients;
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 * @init_irq: IRQ that was set at initialization
304 * @irq: indicates the IRQ generated by this device (if any)
305 * @detected: member of an i2c_driver.clients list or i2c-core's
306 * userspace_devices list
307 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
308 * calls it to pass on slave events to the slave driver.
309 *
310 * An i2c_client identifies a single device (i.e. chip) connected to an
311 * i2c bus. The behaviour exposed to Linux is defined by the driver
312 * managing the device.
313 */
314struct i2c_client {
315 unsigned short flags; /* div., see below */
316#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
317#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
318 /* Must equal I2C_M_TEN below */
319#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
320#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
321#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
322#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
323 /* Must match I2C_M_STOP|IGNORE_NAK */
324
325 unsigned short addr; /* chip address - NOTE: 7bit */
326 /* addresses are stored in the */
327 /* _LOWER_ 7 bits */
328 char name[I2C_NAME_SIZE];
329 struct i2c_adapter *adapter; /* the adapter we sit on */
330 struct device dev; /* the device structure */
331 int init_irq; /* irq set at initialization */
332 int irq; /* irq issued by device */
333 struct list_head detected;
334#if IS_ENABLED(CONFIG_I2C_SLAVE)
335 i2c_slave_cb_t slave_cb; /* callback for slave mode */
336#endif
337};
338#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
339
340struct i2c_client *i2c_verify_client(struct device *dev);
341struct i2c_adapter *i2c_verify_adapter(struct device *dev);
342const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
343 const struct i2c_client *client);
344
345static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
346{
347 struct device * const dev = container_of(kobj, struct device, kobj);
348 return to_i2c_client(dev);
349}
350
351static inline void *i2c_get_clientdata(const struct i2c_client *client)
352{
353 return dev_get_drvdata(&client->dev);
354}
355
356static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
357{
358 dev_set_drvdata(&client->dev, data);
359}
360
361/* I2C slave support */
362
363#if IS_ENABLED(CONFIG_I2C_SLAVE)
364enum i2c_slave_event {
365 I2C_SLAVE_READ_REQUESTED,
366 I2C_SLAVE_WRITE_REQUESTED,
367 I2C_SLAVE_READ_PROCESSED,
368 I2C_SLAVE_WRITE_RECEIVED,
369 I2C_SLAVE_STOP,
370};
371
372int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
373int i2c_slave_unregister(struct i2c_client *client);
374bool i2c_detect_slave_mode(struct device *dev);
375
376static inline int i2c_slave_event(struct i2c_client *client,
377 enum i2c_slave_event event, u8 *val)
378{
379 return client->slave_cb(client, event, val);
380}
381#else
382static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
383#endif
384
385/**
386 * struct i2c_board_info - template for device creation
387 * @type: chip type, to initialize i2c_client.name
388 * @flags: to initialize i2c_client.flags
389 * @addr: stored in i2c_client.addr
390 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
391 * @platform_data: stored in i2c_client.dev.platform_data
392 * @of_node: pointer to OpenFirmware device node
393 * @fwnode: device node supplied by the platform firmware
394 * @properties: additional device properties for the device
395 * @resources: resources associated with the device
396 * @num_resources: number of resources in the @resources array
397 * @irq: stored in i2c_client.irq
398 *
399 * I2C doesn't actually support hardware probing, although controllers and
400 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
401 * a device at a given address. Drivers commonly need more information than
402 * that, such as chip type, configuration, associated IRQ, and so on.
403 *
404 * i2c_board_info is used to build tables of information listing I2C devices
405 * that are present. This information is used to grow the driver model tree.
406 * For mainboards this is done statically using i2c_register_board_info();
407 * bus numbers identify adapters that aren't yet available. For add-on boards,
408 * i2c_new_client_device() does this dynamically with the adapter already known.
409 */
410struct i2c_board_info {
411 char type[I2C_NAME_SIZE];
412 unsigned short flags;
413 unsigned short addr;
414 const char *dev_name;
415 void *platform_data;
416 struct device_node *of_node;
417 struct fwnode_handle *fwnode;
418 const struct property_entry *properties;
419 const struct resource *resources;
420 unsigned int num_resources;
421 int irq;
422};
423
424/**
425 * I2C_BOARD_INFO - macro used to list an i2c device and its address
426 * @dev_type: identifies the device type
427 * @dev_addr: the device's address on the bus.
428 *
429 * This macro initializes essential fields of a struct i2c_board_info,
430 * declaring what has been provided on a particular board. Optional
431 * fields (such as associated irq, or device-specific platform_data)
432 * are provided using conventional syntax.
433 */
434#define I2C_BOARD_INFO(dev_type, dev_addr) \
435 .type = dev_type, .addr = (dev_addr)
436
437
438#if IS_ENABLED(CONFIG_I2C)
439/*
440 * Add-on boards should register/unregister their devices; e.g. a board
441 * with integrated I2C, a config eeprom, sensors, and a codec that's
442 * used in conjunction with the primary hardware.
443 */
444struct i2c_client *
445i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
446
447/* If you don't know the exact address of an I2C device, use this variant
448 * instead, which can probe for device presence in a list of possible
449 * addresses. The "probe" callback function is optional. If it is provided,
450 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
451 * a default probing method is used.
452 */
453struct i2c_client *
454i2c_new_scanned_device(struct i2c_adapter *adap,
455 struct i2c_board_info *info,
456 unsigned short const *addr_list,
457 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
458
459/* Common custom probe functions */
460int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
461
462struct i2c_client *
463i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
464
465struct i2c_client *
466devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
467
468struct i2c_client *
469i2c_new_ancillary_device(struct i2c_client *client,
470 const char *name,
471 u16 default_addr);
472
473void i2c_unregister_device(struct i2c_client *client);
474#endif /* I2C */
475
476/* Mainboard arch_initcall() code should register all its I2C devices.
477 * This is done at arch_initcall time, before declaring any i2c adapters.
478 * Modules for add-on boards must use other calls.
479 */
480#ifdef CONFIG_I2C_BOARDINFO
481int
482i2c_register_board_info(int busnum, struct i2c_board_info const *info,
483 unsigned n);
484#else
485static inline int
486i2c_register_board_info(int busnum, struct i2c_board_info const *info,
487 unsigned n)
488{
489 return 0;
490}
491#endif /* I2C_BOARDINFO */
492
493/**
494 * struct i2c_algorithm - represent I2C transfer method
495 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
496 * defined by the msgs array, with num messages available to transfer via
497 * the adapter specified by adap.
498 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
499 * so e.g. PMICs can be accessed very late before shutdown. Optional.
500 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
501 * is not present, then the bus layer will try and convert the SMBus calls
502 * into I2C transfers instead.
503 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
504 * so e.g. PMICs can be accessed very late before shutdown. Optional.
505 * @functionality: Return the flags that this algorithm/adapter pair supports
506 * from the ``I2C_FUNC_*`` flags.
507 * @reg_slave: Register given client to I2C slave mode of this adapter
508 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
509 *
510 * The following structs are for those who like to implement new bus drivers:
511 * i2c_algorithm is the interface to a class of hardware solutions which can
512 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
513 * to name two of the most common.
514 *
515 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
516 * type of error code that occurred during the transfer, as documented in the
517 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
518 */
519struct i2c_algorithm {
520 /*
521 * If an adapter algorithm can't do I2C-level access, set master_xfer
522 * to NULL. If an adapter algorithm can do SMBus access, set
523 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
524 * using common I2C messages.
525 *
526 * master_xfer should return the number of messages successfully
527 * processed, or a negative value on error
528 */
529 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
530 int num);
531 int (*master_xfer_atomic)(struct i2c_adapter *adap,
532 struct i2c_msg *msgs, int num);
533 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
534 unsigned short flags, char read_write,
535 u8 command, int size, union i2c_smbus_data *data);
536 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
537 unsigned short flags, char read_write,
538 u8 command, int size, union i2c_smbus_data *data);
539
540 /* To determine what the adapter supports */
541 u32 (*functionality)(struct i2c_adapter *adap);
542
543#if IS_ENABLED(CONFIG_I2C_SLAVE)
544 int (*reg_slave)(struct i2c_client *client);
545 int (*unreg_slave)(struct i2c_client *client);
546#endif
547};
548
549/**
550 * struct i2c_lock_operations - represent I2C locking operations
551 * @lock_bus: Get exclusive access to an I2C bus segment
552 * @trylock_bus: Try to get exclusive access to an I2C bus segment
553 * @unlock_bus: Release exclusive access to an I2C bus segment
554 *
555 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
556 */
557struct i2c_lock_operations {
558 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
559 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
560 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
561};
562
563/**
564 * struct i2c_timings - I2C timing information
565 * @bus_freq_hz: the bus frequency in Hz
566 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
567 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
568 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
569 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
570 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
571 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
572 * digital filter can filter out
573 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
574 * analog filter
575 */
576struct i2c_timings {
577 u32 bus_freq_hz;
578 u32 scl_rise_ns;
579 u32 scl_fall_ns;
580 u32 scl_int_delay_ns;
581 u32 sda_fall_ns;
582 u32 sda_hold_ns;
583 u32 digital_filter_width_ns;
584 u32 analog_filter_cutoff_freq_hz;
585};
586
587/**
588 * struct i2c_bus_recovery_info - I2C bus recovery information
589 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
590 * i2c_generic_scl_recovery().
591 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
592 * recovery. Populated internally for generic GPIO recovery.
593 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
594 * Populated internally for generic GPIO recovery.
595 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
596 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
597 * GPIO, for generic GPIO recovery.
598 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
599 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
600 * for generic GPIO recovery.
601 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
602 * has a more complex internal logic than just reading SDA. Optional.
603 * @prepare_recovery: This will be called before starting recovery. Platform may
604 * configure padmux here for SDA/SCL line or something else they want.
605 * @unprepare_recovery: This will be called after completing recovery. Platform
606 * may configure padmux here for SDA/SCL line or something else they want.
607 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
608 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
609 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
610 * Optional.
611 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
612 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
613 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
614 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
615 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
616 * is called "gpio" or "recovery" and pinctrl is valid.
617 */
618struct i2c_bus_recovery_info {
619 int (*recover_bus)(struct i2c_adapter *adap);
620
621 int (*get_scl)(struct i2c_adapter *adap);
622 void (*set_scl)(struct i2c_adapter *adap, int val);
623 int (*get_sda)(struct i2c_adapter *adap);
624 void (*set_sda)(struct i2c_adapter *adap, int val);
625 int (*get_bus_free)(struct i2c_adapter *adap);
626
627 void (*prepare_recovery)(struct i2c_adapter *adap);
628 void (*unprepare_recovery)(struct i2c_adapter *adap);
629
630 /* gpio recovery */
631 struct gpio_desc *scl_gpiod;
632 struct gpio_desc *sda_gpiod;
633 struct pinctrl *pinctrl;
634 struct pinctrl_state *pins_default;
635 struct pinctrl_state *pins_gpio;
636};
637
638int i2c_recover_bus(struct i2c_adapter *adap);
639
640/* Generic recovery routines */
641int i2c_generic_scl_recovery(struct i2c_adapter *adap);
642
643/**
644 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
645 * @flags: see I2C_AQ_* for possible flags and read below
646 * @max_num_msgs: maximum number of messages per transfer
647 * @max_write_len: maximum length of a write message
648 * @max_read_len: maximum length of a read message
649 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
650 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
651 *
652 * Note about combined messages: Some I2C controllers can only send one message
653 * per transfer, plus something called combined message or write-then-read.
654 * This is (usually) a small write message followed by a read message and
655 * barely enough to access register based devices like EEPROMs. There is a flag
656 * to support this mode. It implies max_num_msg = 2 and does the length checks
657 * with max_comb_*_len because combined message mode usually has its own
658 * limitations. Because of HW implementations, some controllers can actually do
659 * write-then-anything or other variants. To support that, write-then-read has
660 * been broken out into smaller bits like write-first and read-second which can
661 * be combined as needed.
662 */
663
664struct i2c_adapter_quirks {
665 u64 flags;
666 int max_num_msgs;
667 u16 max_write_len;
668 u16 max_read_len;
669 u16 max_comb_1st_msg_len;
670 u16 max_comb_2nd_msg_len;
671};
672
673/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
674#define I2C_AQ_COMB BIT(0)
675/* first combined message must be write */
676#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
677/* second combined message must be read */
678#define I2C_AQ_COMB_READ_SECOND BIT(2)
679/* both combined messages must have the same target address */
680#define I2C_AQ_COMB_SAME_ADDR BIT(3)
681/* convenience macro for typical write-then read case */
682#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
683 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
684/* clock stretching is not supported */
685#define I2C_AQ_NO_CLK_STRETCH BIT(4)
686/* message cannot have length of 0 */
687#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
688#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
689#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
690
691/*
692 * i2c_adapter is the structure used to identify a physical i2c bus along
693 * with the access algorithms necessary to access it.
694 */
695struct i2c_adapter {
696 struct module *owner;
697 unsigned int class; /* classes to allow probing for */
698 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
699 void *algo_data;
700
701 /* data fields that are valid for all devices */
702 const struct i2c_lock_operations *lock_ops;
703 struct rt_mutex bus_lock;
704 struct rt_mutex mux_lock;
705
706 int timeout; /* in jiffies */
707 int retries;
708 struct device dev; /* the adapter device */
709 unsigned long locked_flags; /* owned by the I2C core */
710#define I2C_ALF_IS_SUSPENDED 0
711#define I2C_ALF_SUSPEND_REPORTED 1
712
713 int nr;
714 char name[48];
715 struct completion dev_released;
716
717 struct mutex userspace_clients_lock;
718 struct list_head userspace_clients;
719
720 struct i2c_bus_recovery_info *bus_recovery_info;
721 const struct i2c_adapter_quirks *quirks;
722
723 struct irq_domain *host_notify_domain;
724};
725#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
726
727static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
728{
729 return dev_get_drvdata(&adap->dev);
730}
731
732static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
733{
734 dev_set_drvdata(&adap->dev, data);
735}
736
737static inline struct i2c_adapter *
738i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
739{
740#if IS_ENABLED(CONFIG_I2C_MUX)
741 struct device *parent = adapter->dev.parent;
742
743 if (parent != NULL && parent->type == &i2c_adapter_type)
744 return to_i2c_adapter(parent);
745 else
746#endif
747 return NULL;
748}
749
750int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
751
752/* Adapter locking functions, exported for shared pin cases */
753#define I2C_LOCK_ROOT_ADAPTER BIT(0)
754#define I2C_LOCK_SEGMENT BIT(1)
755
756/**
757 * i2c_lock_bus - Get exclusive access to an I2C bus segment
758 * @adapter: Target I2C bus segment
759 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
760 * locks only this branch in the adapter tree
761 */
762static inline void
763i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
764{
765 adapter->lock_ops->lock_bus(adapter, flags);
766}
767
768/**
769 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
770 * @adapter: Target I2C bus segment
771 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
772 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
773 *
774 * Return: true if the I2C bus segment is locked, false otherwise
775 */
776static inline int
777i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
778{
779 return adapter->lock_ops->trylock_bus(adapter, flags);
780}
781
782/**
783 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
784 * @adapter: Target I2C bus segment
785 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
786 * unlocks only this branch in the adapter tree
787 */
788static inline void
789i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
790{
791 adapter->lock_ops->unlock_bus(adapter, flags);
792}
793
794/**
795 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
796 * @adap: Adapter to mark as suspended
797 *
798 * When using this helper to mark an adapter as suspended, the core will reject
799 * further transfers to this adapter. The usage of this helper is optional but
800 * recommended for devices having distinct handlers for system suspend and
801 * runtime suspend. More complex devices are free to implement custom solutions
802 * to reject transfers when suspended.
803 */
804static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
805{
806 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
807 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
808 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
809}
810
811/**
812 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
813 * @adap: Adapter to mark as resumed
814 *
815 * When using this helper to mark an adapter as resumed, the core will allow
816 * further transfers to this adapter. See also further notes to
817 * @i2c_mark_adapter_suspended().
818 */
819static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
820{
821 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
822 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
823 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
824}
825
826/* i2c adapter classes (bitmask) */
827#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
828#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
829#define I2C_CLASS_SPD (1<<7) /* Memory modules */
830/* Warn users that the adapter doesn't support classes anymore */
831#define I2C_CLASS_DEPRECATED (1<<8)
832
833/* Internal numbers to terminate lists */
834#define I2C_CLIENT_END 0xfffeU
835
836/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
837#define I2C_ADDRS(addr, addrs...) \
838 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
839
840
841/* ----- functions exported by i2c.o */
842
843/* administration...
844 */
845#if IS_ENABLED(CONFIG_I2C)
846int i2c_add_adapter(struct i2c_adapter *adap);
847void i2c_del_adapter(struct i2c_adapter *adap);
848int i2c_add_numbered_adapter(struct i2c_adapter *adap);
849
850int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
851void i2c_del_driver(struct i2c_driver *driver);
852
853/* use a define to avoid include chaining to get THIS_MODULE */
854#define i2c_add_driver(driver) \
855 i2c_register_driver(THIS_MODULE, driver)
856
857static inline bool i2c_client_has_driver(struct i2c_client *client)
858{
859 return !IS_ERR_OR_NULL(client) && client->dev.driver;
860}
861
862/* call the i2c_client->command() of all attached clients with
863 * the given arguments */
864void i2c_clients_command(struct i2c_adapter *adap,
865 unsigned int cmd, void *arg);
866
867struct i2c_adapter *i2c_get_adapter(int nr);
868void i2c_put_adapter(struct i2c_adapter *adap);
869unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
870
871void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
872
873/* Return the functionality mask */
874static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
875{
876 return adap->algo->functionality(adap);
877}
878
879/* Return 1 if adapter supports everything we need, 0 if not. */
880static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
881{
882 return (func & i2c_get_functionality(adap)) == func;
883}
884
885/**
886 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
887 * @adap: i2c adapter
888 * @quirks: quirk flags
889 *
890 * Return: true if the adapter has all the specified quirk flags, false if not
891 */
892static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
893{
894 if (!adap->quirks)
895 return false;
896 return (adap->quirks->flags & quirks) == quirks;
897}
898
899/* Return the adapter number for a specific adapter */
900static inline int i2c_adapter_id(struct i2c_adapter *adap)
901{
902 return adap->nr;
903}
904
905static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
906{
907 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
908}
909
910u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
911void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
912
913int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
914/**
915 * module_i2c_driver() - Helper macro for registering a modular I2C driver
916 * @__i2c_driver: i2c_driver struct
917 *
918 * Helper macro for I2C drivers which do not do anything special in module
919 * init/exit. This eliminates a lot of boilerplate. Each module may only
920 * use this macro once, and calling it replaces module_init() and module_exit()
921 */
922#define module_i2c_driver(__i2c_driver) \
923 module_driver(__i2c_driver, i2c_add_driver, \
924 i2c_del_driver)
925
926/**
927 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
928 * @__i2c_driver: i2c_driver struct
929 *
930 * Helper macro for I2C drivers which do not do anything special in their
931 * init. This eliminates a lot of boilerplate. Each driver may only
932 * use this macro once, and calling it replaces device_initcall().
933 */
934#define builtin_i2c_driver(__i2c_driver) \
935 builtin_driver(__i2c_driver, i2c_add_driver)
936
937#endif /* I2C */
938
939#if IS_ENABLED(CONFIG_OF)
940/* must call put_device() when done with returned i2c_client device */
941struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
942
943/* must call put_device() when done with returned i2c_adapter device */
944struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
945
946/* must call i2c_put_adapter() when done with returned i2c_adapter device */
947struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
948
949const struct of_device_id
950*i2c_of_match_device(const struct of_device_id *matches,
951 struct i2c_client *client);
952
953int of_i2c_get_board_info(struct device *dev, struct device_node *node,
954 struct i2c_board_info *info);
955
956#else
957
958static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
959{
960 return NULL;
961}
962
963static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
964{
965 return NULL;
966}
967
968static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
969{
970 return NULL;
971}
972
973static inline const struct of_device_id
974*i2c_of_match_device(const struct of_device_id *matches,
975 struct i2c_client *client)
976{
977 return NULL;
978}
979
980static inline int of_i2c_get_board_info(struct device *dev,
981 struct device_node *node,
982 struct i2c_board_info *info)
983{
984 return -ENOTSUPP;
985}
986
987#endif /* CONFIG_OF */
988
989struct acpi_resource;
990struct acpi_resource_i2c_serialbus;
991
992#if IS_ENABLED(CONFIG_ACPI)
993bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
994 struct acpi_resource_i2c_serialbus **i2c);
995u32 i2c_acpi_find_bus_speed(struct device *dev);
996struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
997 struct i2c_board_info *info);
998struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
999#else
1000static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1001 struct acpi_resource_i2c_serialbus **i2c)
1002{
1003 return false;
1004}
1005static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1006{
1007 return 0;
1008}
1009static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1010 int index, struct i2c_board_info *info)
1011{
1012 return ERR_PTR(-ENODEV);
1013}
1014static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1015{
1016 return NULL;
1017}
1018#endif /* CONFIG_ACPI */
1019
1020#endif /* _LINUX_I2C_H */
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_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);
192const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client);
193#endif /* I2C */
194
195/**
196 * struct i2c_device_identity - i2c client device identification
197 * @manufacturer_id: 0 - 4095, database maintained by NXP
198 * @part_id: 0 - 511, according to manufacturer
199 * @die_revision: 0 - 7, according to manufacturer
200 */
201struct i2c_device_identity {
202 u16 manufacturer_id;
203#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
204#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
205#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
206#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
207#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
208#define I2C_DEVICE_ID_ANALOG_DEVICES 5
209#define I2C_DEVICE_ID_STMICROELECTRONICS 6
210#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
211#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
212#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
213#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
214#define I2C_DEVICE_ID_FLIR 11
215#define I2C_DEVICE_ID_O2MICRO 12
216#define I2C_DEVICE_ID_ATMEL 13
217#define I2C_DEVICE_ID_NONE 0xffff
218 u16 part_id;
219 u8 die_revision;
220};
221
222enum i2c_alert_protocol {
223 I2C_PROTOCOL_SMBUS_ALERT,
224 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
225};
226
227/**
228 * enum i2c_driver_flags - Flags for an I2C device driver
229 *
230 * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe
231 */
232enum i2c_driver_flags {
233 I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0),
234};
235
236/**
237 * struct i2c_driver - represent an I2C device driver
238 * @class: What kind of i2c device we instantiate (for detect)
239 * @probe: 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);
276 void (*remove)(struct i2c_client *client);
277
278
279 /* driver model interfaces that don't relate to enumeration */
280 void (*shutdown)(struct i2c_client *client);
281
282 /* Alert callback, for example for the SMBus alert protocol.
283 * The format and meaning of the data value depends on the protocol.
284 * For the SMBus alert protocol, there is a single bit of data passed
285 * as the alert response's low bit ("event flag").
286 * For the SMBus Host Notify protocol, the data corresponds to the
287 * 16-bit payload data reported by the slave device acting as master.
288 */
289 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
290 unsigned int data);
291
292 /* a ioctl like command that can be used to perform specific functions
293 * with the device.
294 */
295 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
296
297 struct device_driver driver;
298 const struct i2c_device_id *id_table;
299
300 /* Device detection callback for automatic device creation */
301 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
302 const unsigned short *address_list;
303 struct list_head clients;
304
305 u32 flags;
306};
307#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
308
309/**
310 * struct i2c_client - represent an I2C slave device
311 * @flags: see I2C_CLIENT_* for possible flags
312 * @addr: Address used on the I2C bus connected to the parent adapter.
313 * @name: Indicates the type of the device, usually a chip name that's
314 * generic enough to hide second-sourcing and compatible revisions.
315 * @adapter: manages the bus segment hosting this I2C device
316 * @dev: Driver model device node for the slave.
317 * @init_irq: IRQ that was set at initialization
318 * @irq: indicates the IRQ generated by this device (if any)
319 * @detected: member of an i2c_driver.clients list or i2c-core's
320 * userspace_devices list
321 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
322 * calls it to pass on slave events to the slave driver.
323 * @devres_group_id: id of the devres group that will be created for resources
324 * acquired when probing this device.
325 *
326 * An i2c_client identifies a single device (i.e. chip) connected to an
327 * i2c bus. The behaviour exposed to Linux is defined by the driver
328 * managing the device.
329 */
330struct i2c_client {
331 unsigned short flags; /* div., see below */
332#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
333#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
334 /* Must equal I2C_M_TEN below */
335#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
336#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
337#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
338#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
339 /* Must match I2C_M_STOP|IGNORE_NAK */
340
341 unsigned short addr; /* chip address - NOTE: 7bit */
342 /* addresses are stored in the */
343 /* _LOWER_ 7 bits */
344 char name[I2C_NAME_SIZE];
345 struct i2c_adapter *adapter; /* the adapter we sit on */
346 struct device dev; /* the device structure */
347 int init_irq; /* irq set at initialization */
348 int irq; /* irq issued by device */
349 struct list_head detected;
350#if IS_ENABLED(CONFIG_I2C_SLAVE)
351 i2c_slave_cb_t slave_cb; /* callback for slave mode */
352#endif
353 void *devres_group_id; /* ID of probe devres group */
354};
355#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
356
357struct i2c_adapter *i2c_verify_adapter(struct device *dev);
358const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
359 const struct i2c_client *client);
360
361const void *i2c_get_match_data(const struct i2c_client *client);
362
363static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
364{
365 struct device * const dev = kobj_to_dev(kobj);
366 return to_i2c_client(dev);
367}
368
369static inline void *i2c_get_clientdata(const struct i2c_client *client)
370{
371 return dev_get_drvdata(&client->dev);
372}
373
374static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
375{
376 dev_set_drvdata(&client->dev, data);
377}
378
379/* I2C slave support */
380
381enum i2c_slave_event {
382 I2C_SLAVE_READ_REQUESTED,
383 I2C_SLAVE_WRITE_REQUESTED,
384 I2C_SLAVE_READ_PROCESSED,
385 I2C_SLAVE_WRITE_RECEIVED,
386 I2C_SLAVE_STOP,
387};
388
389int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
390int i2c_slave_unregister(struct i2c_client *client);
391int i2c_slave_event(struct i2c_client *client,
392 enum i2c_slave_event event, u8 *val);
393#if IS_ENABLED(CONFIG_I2C_SLAVE)
394bool i2c_detect_slave_mode(struct device *dev);
395#else
396static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
397#endif
398
399/**
400 * struct i2c_board_info - template for device creation
401 * @type: chip type, to initialize i2c_client.name
402 * @flags: to initialize i2c_client.flags
403 * @addr: stored in i2c_client.addr
404 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
405 * @platform_data: stored in i2c_client.dev.platform_data
406 * @of_node: pointer to OpenFirmware device node
407 * @fwnode: device node supplied by the platform firmware
408 * @swnode: software node for the device
409 * @resources: resources associated with the device
410 * @num_resources: number of resources in the @resources array
411 * @irq: stored in i2c_client.irq
412 *
413 * I2C doesn't actually support hardware probing, although controllers and
414 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
415 * a device at a given address. Drivers commonly need more information than
416 * that, such as chip type, configuration, associated IRQ, and so on.
417 *
418 * i2c_board_info is used to build tables of information listing I2C devices
419 * that are present. This information is used to grow the driver model tree.
420 * For mainboards this is done statically using i2c_register_board_info();
421 * bus numbers identify adapters that aren't yet available. For add-on boards,
422 * i2c_new_client_device() does this dynamically with the adapter already known.
423 */
424struct i2c_board_info {
425 char type[I2C_NAME_SIZE];
426 unsigned short flags;
427 unsigned short addr;
428 const char *dev_name;
429 void *platform_data;
430 struct device_node *of_node;
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 method
516 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
517 * defined by the msgs array, with num messages available to transfer via
518 * the adapter specified by adap.
519 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
520 * so e.g. PMICs can be accessed very late before shutdown. Optional.
521 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
522 * is not present, then the bus layer will try and convert the SMBus calls
523 * into I2C transfers instead.
524 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
525 * so e.g. PMICs can be accessed very late before shutdown. Optional.
526 * @functionality: Return the flags that this algorithm/adapter pair supports
527 * from the ``I2C_FUNC_*`` flags.
528 * @reg_slave: Register given client to I2C slave mode of this adapter
529 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
530 *
531 * The following structs are for those who like to implement new bus drivers:
532 * i2c_algorithm is the interface to a class of hardware solutions which can
533 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
534 * to name two of the most common.
535 *
536 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
537 * type of error code that occurred during the transfer, as documented in the
538 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
539 * number of messages executed should be returned.
540 */
541struct i2c_algorithm {
542 /*
543 * If an adapter algorithm can't do I2C-level access, set master_xfer
544 * to NULL. If an adapter algorithm can do SMBus access, set
545 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
546 * using common I2C messages.
547 *
548 * master_xfer should return the number of messages successfully
549 * processed, or a negative value on error
550 */
551 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
552 int num);
553 int (*master_xfer_atomic)(struct i2c_adapter *adap,
554 struct i2c_msg *msgs, int num);
555 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
556 unsigned short flags, char read_write,
557 u8 command, int size, union i2c_smbus_data *data);
558 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
559 unsigned short flags, char read_write,
560 u8 command, int size, union i2c_smbus_data *data);
561
562 /* To determine what the adapter supports */
563 u32 (*functionality)(struct i2c_adapter *adap);
564
565#if IS_ENABLED(CONFIG_I2C_SLAVE)
566 int (*reg_slave)(struct i2c_client *client);
567 int (*unreg_slave)(struct i2c_client *client);
568#endif
569};
570
571/**
572 * struct i2c_lock_operations - represent I2C locking operations
573 * @lock_bus: Get exclusive access to an I2C bus segment
574 * @trylock_bus: Try to get exclusive access to an I2C bus segment
575 * @unlock_bus: Release exclusive access to an I2C bus segment
576 *
577 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
578 */
579struct i2c_lock_operations {
580 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
581 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
582 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
583};
584
585/**
586 * struct i2c_timings - I2C timing information
587 * @bus_freq_hz: the bus frequency in Hz
588 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
589 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
590 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
591 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
592 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
593 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
594 * digital filter can filter out
595 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
596 * analog filter
597 */
598struct i2c_timings {
599 u32 bus_freq_hz;
600 u32 scl_rise_ns;
601 u32 scl_fall_ns;
602 u32 scl_int_delay_ns;
603 u32 sda_fall_ns;
604 u32 sda_hold_ns;
605 u32 digital_filter_width_ns;
606 u32 analog_filter_cutoff_freq_hz;
607};
608
609/**
610 * struct i2c_bus_recovery_info - I2C bus recovery information
611 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
612 * i2c_generic_scl_recovery().
613 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
614 * recovery. Populated internally for generic GPIO recovery.
615 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
616 * Populated internally for generic GPIO recovery.
617 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
618 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
619 * GPIO, for generic GPIO recovery.
620 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
621 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
622 * for generic GPIO recovery.
623 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
624 * has a more complex internal logic than just reading SDA. Optional.
625 * @prepare_recovery: This will be called before starting recovery. Platform may
626 * configure padmux here for SDA/SCL line or something else they want.
627 * @unprepare_recovery: This will be called after completing recovery. Platform
628 * may configure padmux here for SDA/SCL line or something else they want.
629 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
630 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
631 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
632 * Optional.
633 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
634 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
635 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
636 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
637 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
638 * is called "gpio" or "recovery" and pinctrl is valid.
639 */
640struct i2c_bus_recovery_info {
641 int (*recover_bus)(struct i2c_adapter *adap);
642
643 int (*get_scl)(struct i2c_adapter *adap);
644 void (*set_scl)(struct i2c_adapter *adap, int val);
645 int (*get_sda)(struct i2c_adapter *adap);
646 void (*set_sda)(struct i2c_adapter *adap, int val);
647 int (*get_bus_free)(struct i2c_adapter *adap);
648
649 void (*prepare_recovery)(struct i2c_adapter *adap);
650 void (*unprepare_recovery)(struct i2c_adapter *adap);
651
652 /* gpio recovery */
653 struct gpio_desc *scl_gpiod;
654 struct gpio_desc *sda_gpiod;
655 struct pinctrl *pinctrl;
656 struct pinctrl_state *pins_default;
657 struct pinctrl_state *pins_gpio;
658};
659
660int i2c_recover_bus(struct i2c_adapter *adap);
661
662/* Generic recovery routines */
663int i2c_generic_scl_recovery(struct i2c_adapter *adap);
664
665/**
666 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
667 * @flags: see I2C_AQ_* for possible flags and read below
668 * @max_num_msgs: maximum number of messages per transfer
669 * @max_write_len: maximum length of a write message
670 * @max_read_len: maximum length of a read message
671 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
672 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
673 *
674 * Note about combined messages: Some I2C controllers can only send one message
675 * per transfer, plus something called combined message or write-then-read.
676 * This is (usually) a small write message followed by a read message and
677 * barely enough to access register based devices like EEPROMs. There is a flag
678 * to support this mode. It implies max_num_msg = 2 and does the length checks
679 * with max_comb_*_len because combined message mode usually has its own
680 * limitations. Because of HW implementations, some controllers can actually do
681 * write-then-anything or other variants. To support that, write-then-read has
682 * been broken out into smaller bits like write-first and read-second which can
683 * be combined as needed.
684 */
685
686struct i2c_adapter_quirks {
687 u64 flags;
688 int max_num_msgs;
689 u16 max_write_len;
690 u16 max_read_len;
691 u16 max_comb_1st_msg_len;
692 u16 max_comb_2nd_msg_len;
693};
694
695/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
696#define I2C_AQ_COMB BIT(0)
697/* first combined message must be write */
698#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
699/* second combined message must be read */
700#define I2C_AQ_COMB_READ_SECOND BIT(2)
701/* both combined messages must have the same target address */
702#define I2C_AQ_COMB_SAME_ADDR BIT(3)
703/* convenience macro for typical write-then read case */
704#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
705 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
706/* clock stretching is not supported */
707#define I2C_AQ_NO_CLK_STRETCH BIT(4)
708/* message cannot have length of 0 */
709#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
710#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
711#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
712/* adapter cannot do repeated START */
713#define I2C_AQ_NO_REP_START BIT(7)
714
715/*
716 * i2c_adapter is the structure used to identify a physical i2c bus along
717 * with the access algorithms necessary to access it.
718 */
719struct i2c_adapter {
720 struct module *owner;
721 unsigned int class; /* classes to allow probing for */
722 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
723 void *algo_data;
724
725 /* data fields that are valid for all devices */
726 const struct i2c_lock_operations *lock_ops;
727 struct rt_mutex bus_lock;
728 struct rt_mutex mux_lock;
729
730 int timeout; /* in jiffies */
731 int retries;
732 struct device dev; /* the adapter device */
733 unsigned long locked_flags; /* owned by the I2C core */
734#define I2C_ALF_IS_SUSPENDED 0
735#define I2C_ALF_SUSPEND_REPORTED 1
736
737 int nr;
738 char name[48];
739 struct completion dev_released;
740
741 struct mutex userspace_clients_lock;
742 struct list_head userspace_clients;
743
744 struct i2c_bus_recovery_info *bus_recovery_info;
745 const struct i2c_adapter_quirks *quirks;
746
747 struct irq_domain *host_notify_domain;
748 struct regulator *bus_regulator;
749
750 struct dentry *debugfs;
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_SPD (1<<7) /* Memory modules */
856/* Warn users that the adapter doesn't support classes anymore */
857#define I2C_CLASS_DEPRECATED (1<<8)
858
859/* Internal numbers to terminate lists */
860#define I2C_CLIENT_END 0xfffeU
861
862/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
863#define I2C_ADDRS(addr, addrs...) \
864 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
865
866
867/* ----- functions exported by i2c.o */
868
869/* administration...
870 */
871#if IS_ENABLED(CONFIG_I2C)
872int i2c_add_adapter(struct i2c_adapter *adap);
873int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
874void i2c_del_adapter(struct i2c_adapter *adap);
875int i2c_add_numbered_adapter(struct i2c_adapter *adap);
876
877int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
878void i2c_del_driver(struct i2c_driver *driver);
879
880/* use a define to avoid include chaining to get THIS_MODULE */
881#define i2c_add_driver(driver) \
882 i2c_register_driver(THIS_MODULE, driver)
883
884static inline bool i2c_client_has_driver(struct i2c_client *client)
885{
886 return !IS_ERR_OR_NULL(client) && client->dev.driver;
887}
888
889/* call the i2c_client->command() of all attached clients with
890 * the given arguments */
891void i2c_clients_command(struct i2c_adapter *adap,
892 unsigned int cmd, void *arg);
893
894struct i2c_adapter *i2c_get_adapter(int nr);
895void i2c_put_adapter(struct i2c_adapter *adap);
896unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
897
898void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
899
900/* Return the functionality mask */
901static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
902{
903 return adap->algo->functionality(adap);
904}
905
906/* Return 1 if adapter supports everything we need, 0 if not. */
907static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
908{
909 return (func & i2c_get_functionality(adap)) == func;
910}
911
912/**
913 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
914 * @adap: i2c adapter
915 * @quirks: quirk flags
916 *
917 * Return: true if the adapter has all the specified quirk flags, false if not
918 */
919static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
920{
921 if (!adap->quirks)
922 return false;
923 return (adap->quirks->flags & quirks) == quirks;
924}
925
926/* Return the adapter number for a specific adapter */
927static inline int i2c_adapter_id(struct i2c_adapter *adap)
928{
929 return adap->nr;
930}
931
932static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
933{
934 return (msg->addr << 1) | (msg->flags & I2C_M_RD);
935}
936
937u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
938void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
939
940int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
941/**
942 * module_i2c_driver() - Helper macro for registering a modular I2C driver
943 * @__i2c_driver: i2c_driver struct
944 *
945 * Helper macro for I2C drivers which do not do anything special in module
946 * init/exit. This eliminates a lot of boilerplate. Each module may only
947 * use this macro once, and calling it replaces module_init() and module_exit()
948 */
949#define module_i2c_driver(__i2c_driver) \
950 module_driver(__i2c_driver, i2c_add_driver, \
951 i2c_del_driver)
952
953/**
954 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
955 * @__i2c_driver: i2c_driver struct
956 *
957 * Helper macro for I2C drivers which do not do anything special in their
958 * init. This eliminates a lot of boilerplate. Each driver may only
959 * use this macro once, and calling it replaces device_initcall().
960 */
961#define builtin_i2c_driver(__i2c_driver) \
962 builtin_driver(__i2c_driver, i2c_add_driver)
963
964#endif /* I2C */
965
966/* must call put_device() when done with returned i2c_client device */
967struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode);
968
969/* must call put_device() when done with returned i2c_adapter device */
970struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode);
971
972/* must call i2c_put_adapter() when done with returned i2c_adapter device */
973struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode);
974
975#if IS_ENABLED(CONFIG_OF)
976/* must call put_device() when done with returned i2c_client device */
977static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
978{
979 return i2c_find_device_by_fwnode(of_fwnode_handle(node));
980}
981
982/* must call put_device() when done with returned i2c_adapter device */
983static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
984{
985 return i2c_find_adapter_by_fwnode(of_fwnode_handle(node));
986}
987
988/* must call i2c_put_adapter() when done with returned i2c_adapter device */
989static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
990{
991 return i2c_get_adapter_by_fwnode(of_fwnode_handle(node));
992}
993
994const struct of_device_id
995*i2c_of_match_device(const struct of_device_id *matches,
996 struct i2c_client *client);
997
998int of_i2c_get_board_info(struct device *dev, struct device_node *node,
999 struct i2c_board_info *info);
1000
1001#else
1002
1003static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
1004{
1005 return NULL;
1006}
1007
1008static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
1009{
1010 return NULL;
1011}
1012
1013static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
1014{
1015 return NULL;
1016}
1017
1018static inline const struct of_device_id
1019*i2c_of_match_device(const struct of_device_id *matches,
1020 struct i2c_client *client)
1021{
1022 return NULL;
1023}
1024
1025static inline int of_i2c_get_board_info(struct device *dev,
1026 struct device_node *node,
1027 struct i2c_board_info *info)
1028{
1029 return -ENOTSUPP;
1030}
1031
1032#endif /* CONFIG_OF */
1033
1034struct acpi_resource;
1035struct acpi_resource_i2c_serialbus;
1036
1037#if IS_ENABLED(CONFIG_ACPI)
1038bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1039 struct acpi_resource_i2c_serialbus **i2c);
1040int i2c_acpi_client_count(struct acpi_device *adev);
1041u32 i2c_acpi_find_bus_speed(struct device *dev);
1042struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1043 int index,
1044 struct i2c_board_info *info);
1045struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1046bool i2c_acpi_waive_d0_probe(struct device *dev);
1047#else
1048static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1049 struct acpi_resource_i2c_serialbus **i2c)
1050{
1051 return false;
1052}
1053static inline int i2c_acpi_client_count(struct acpi_device *adev)
1054{
1055 return 0;
1056}
1057static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1058{
1059 return 0;
1060}
1061static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1062 struct fwnode_handle *fwnode, int index,
1063 struct i2c_board_info *info)
1064{
1065 return ERR_PTR(-ENODEV);
1066}
1067static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1068{
1069 return NULL;
1070}
1071static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1072{
1073 return false;
1074}
1075#endif /* CONFIG_ACPI */
1076
1077static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1078 int index,
1079 struct i2c_board_info *info)
1080{
1081 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1082}
1083
1084#endif /* _LINUX_I2C_H */