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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/* ------------------------------------------------------------------------- */
2/* */
3/* i2c.h - definitions for the i2c-bus interface */
4/* */
5/* ------------------------------------------------------------------------- */
6/* Copyright (C) 1995-2000 Simon G. Vogl
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 MA 02110-1301 USA. */
22/* ------------------------------------------------------------------------- */
23
24/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
25 Frodo Looijaard <frodol@dds.nl> */
26#ifndef _LINUX_I2C_H
27#define _LINUX_I2C_H
28
29#include <linux/mod_devicetable.h>
30#include <linux/device.h> /* for struct device */
31#include <linux/sched.h> /* for completion */
32#include <linux/mutex.h>
33#include <linux/of.h> /* for struct device_node */
34#include <linux/swab.h> /* for swab16 */
35#include <uapi/linux/i2c.h>
36
37extern struct bus_type i2c_bus_type;
38extern struct device_type i2c_adapter_type;
39
40/* --- General options ------------------------------------------------ */
41
42struct i2c_msg;
43struct i2c_algorithm;
44struct i2c_adapter;
45struct i2c_client;
46struct i2c_driver;
47union i2c_smbus_data;
48struct i2c_board_info;
49
50struct module;
51
52#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
53/*
54 * The master routines are the ones normally used to transmit data to devices
55 * on a bus (or read from them). Apart from two basic transfer functions to
56 * transmit one message at a time, a more complex version can be used to
57 * transmit an arbitrary number of messages without interruption.
58 * @count must be be less than 64k since msg.len is u16.
59 */
60extern int i2c_master_send(const struct i2c_client *client, const char *buf,
61 int count);
62extern int i2c_master_recv(const struct i2c_client *client, char *buf,
63 int count);
64
65/* Transfer num messages.
66 */
67extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
68 int num);
69/* Unlocked flavor */
70extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
71 int num);
72
73/* This is the very generalized SMBus access routine. You probably do not
74 want to use this, though; one of the functions below may be much easier,
75 and probably just as fast.
76 Note that we use i2c_adapter here, because you do not need a specific
77 smbus adapter to call this function. */
78extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
79 unsigned short flags, char read_write, u8 command,
80 int size, union i2c_smbus_data *data);
81
82/* Now follow the 'nice' access routines. These also document the calling
83 conventions of i2c_smbus_xfer. */
84
85extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
86extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
87extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
88 u8 command);
89extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
90 u8 command, u8 value);
91extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
92 u8 command);
93extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
94 u8 command, u16 value);
95
96static inline s32
97i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
98{
99 s32 value = i2c_smbus_read_word_data(client, command);
100
101 return (value < 0) ? value : swab16(value);
102}
103
104static inline s32
105i2c_smbus_write_word_swapped(const struct i2c_client *client,
106 u8 command, u16 value)
107{
108 return i2c_smbus_write_word_data(client, command, swab16(value));
109}
110
111/* Returns the number of read bytes */
112extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
113 u8 command, u8 *values);
114extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
115 u8 command, u8 length, const u8 *values);
116/* Returns the number of read bytes */
117extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
118 u8 command, u8 length, u8 *values);
119extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
120 u8 command, u8 length,
121 const u8 *values);
122#endif /* I2C */
123
124/**
125 * struct i2c_driver - represent an I2C device driver
126 * @class: What kind of i2c device we instantiate (for detect)
127 * @attach_adapter: Callback for bus addition (deprecated)
128 * @probe: Callback for device binding
129 * @remove: Callback for device unbinding
130 * @shutdown: Callback for device shutdown
131 * @suspend: Callback for device suspend
132 * @resume: Callback for device resume
133 * @alert: Alert callback, for example for the SMBus alert protocol
134 * @command: Callback for bus-wide signaling (optional)
135 * @driver: Device driver model driver
136 * @id_table: List of I2C devices supported by this driver
137 * @detect: Callback for device detection
138 * @address_list: The I2C addresses to probe (for detect)
139 * @clients: List of detected clients we created (for i2c-core use only)
140 *
141 * The driver.owner field should be set to the module owner of this driver.
142 * The driver.name field should be set to the name of this driver.
143 *
144 * For automatic device detection, both @detect and @address_list must
145 * be defined. @class should also be set, otherwise only devices forced
146 * with module parameters will be created. The detect function must
147 * fill at least the name field of the i2c_board_info structure it is
148 * handed upon successful detection, and possibly also the flags field.
149 *
150 * If @detect is missing, the driver will still work fine for enumerated
151 * devices. Detected devices simply won't be supported. This is expected
152 * for the many I2C/SMBus devices which can't be detected reliably, and
153 * the ones which can always be enumerated in practice.
154 *
155 * The i2c_client structure which is handed to the @detect callback is
156 * not a real i2c_client. It is initialized just enough so that you can
157 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
158 * else with it. In particular, calling dev_dbg and friends on it is
159 * not allowed.
160 */
161struct i2c_driver {
162 unsigned int class;
163
164 /* Notifies the driver that a new bus has appeared. You should avoid
165 * using this, it will be removed in a near future.
166 */
167 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
168
169 /* Standard driver model interfaces */
170 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
171 int (*remove)(struct i2c_client *);
172
173 /* driver model interfaces that don't relate to enumeration */
174 void (*shutdown)(struct i2c_client *);
175 int (*suspend)(struct i2c_client *, pm_message_t mesg);
176 int (*resume)(struct i2c_client *);
177
178 /* Alert callback, for example for the SMBus alert protocol.
179 * The format and meaning of the data value depends on the protocol.
180 * For the SMBus alert protocol, there is a single bit of data passed
181 * as the alert response's low bit ("event flag").
182 */
183 void (*alert)(struct i2c_client *, unsigned int data);
184
185 /* a ioctl like command that can be used to perform specific functions
186 * with the device.
187 */
188 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
189
190 struct device_driver driver;
191 const struct i2c_device_id *id_table;
192
193 /* Device detection callback for automatic device creation */
194 int (*detect)(struct i2c_client *, struct i2c_board_info *);
195 const unsigned short *address_list;
196 struct list_head clients;
197};
198#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
199
200/**
201 * struct i2c_client - represent an I2C slave device
202 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
203 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
204 * @addr: Address used on the I2C bus connected to the parent adapter.
205 * @name: Indicates the type of the device, usually a chip name that's
206 * generic enough to hide second-sourcing and compatible revisions.
207 * @adapter: manages the bus segment hosting this I2C device
208 * @dev: Driver model device node for the slave.
209 * @irq: indicates the IRQ generated by this device (if any)
210 * @detected: member of an i2c_driver.clients list or i2c-core's
211 * userspace_devices list
212 *
213 * An i2c_client identifies a single device (i.e. chip) connected to an
214 * i2c bus. The behaviour exposed to Linux is defined by the driver
215 * managing the device.
216 */
217struct i2c_client {
218 unsigned short flags; /* div., see below */
219 unsigned short addr; /* chip address - NOTE: 7bit */
220 /* addresses are stored in the */
221 /* _LOWER_ 7 bits */
222 char name[I2C_NAME_SIZE];
223 struct i2c_adapter *adapter; /* the adapter we sit on */
224 struct device dev; /* the device structure */
225 int irq; /* irq issued by device */
226 struct list_head detected;
227};
228#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
229
230extern struct i2c_client *i2c_verify_client(struct device *dev);
231extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
232
233static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
234{
235 struct device * const dev = container_of(kobj, struct device, kobj);
236 return to_i2c_client(dev);
237}
238
239static inline void *i2c_get_clientdata(const struct i2c_client *dev)
240{
241 return dev_get_drvdata(&dev->dev);
242}
243
244static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
245{
246 dev_set_drvdata(&dev->dev, data);
247}
248
249/**
250 * struct i2c_board_info - template for device creation
251 * @type: chip type, to initialize i2c_client.name
252 * @flags: to initialize i2c_client.flags
253 * @addr: stored in i2c_client.addr
254 * @platform_data: stored in i2c_client.dev.platform_data
255 * @archdata: copied into i2c_client.dev.archdata
256 * @of_node: pointer to OpenFirmware device node
257 * @acpi_node: ACPI device node
258 * @irq: stored in i2c_client.irq
259 *
260 * I2C doesn't actually support hardware probing, although controllers and
261 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
262 * a device at a given address. Drivers commonly need more information than
263 * that, such as chip type, configuration, associated IRQ, and so on.
264 *
265 * i2c_board_info is used to build tables of information listing I2C devices
266 * that are present. This information is used to grow the driver model tree.
267 * For mainboards this is done statically using i2c_register_board_info();
268 * bus numbers identify adapters that aren't yet available. For add-on boards,
269 * i2c_new_device() does this dynamically with the adapter already known.
270 */
271struct i2c_board_info {
272 char type[I2C_NAME_SIZE];
273 unsigned short flags;
274 unsigned short addr;
275 void *platform_data;
276 struct dev_archdata *archdata;
277 struct device_node *of_node;
278 struct acpi_dev_node acpi_node;
279 int irq;
280};
281
282/**
283 * I2C_BOARD_INFO - macro used to list an i2c device and its address
284 * @dev_type: identifies the device type
285 * @dev_addr: the device's address on the bus.
286 *
287 * This macro initializes essential fields of a struct i2c_board_info,
288 * declaring what has been provided on a particular board. Optional
289 * fields (such as associated irq, or device-specific platform_data)
290 * are provided using conventional syntax.
291 */
292#define I2C_BOARD_INFO(dev_type, dev_addr) \
293 .type = dev_type, .addr = (dev_addr)
294
295
296#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
297/* Add-on boards should register/unregister their devices; e.g. a board
298 * with integrated I2C, a config eeprom, sensors, and a codec that's
299 * used in conjunction with the primary hardware.
300 */
301extern struct i2c_client *
302i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
303
304/* If you don't know the exact address of an I2C device, use this variant
305 * instead, which can probe for device presence in a list of possible
306 * addresses. The "probe" callback function is optional. If it is provided,
307 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
308 * a default probing method is used.
309 */
310extern struct i2c_client *
311i2c_new_probed_device(struct i2c_adapter *adap,
312 struct i2c_board_info *info,
313 unsigned short const *addr_list,
314 int (*probe)(struct i2c_adapter *, unsigned short addr));
315
316/* Common custom probe functions */
317extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
318
319/* For devices that use several addresses, use i2c_new_dummy() to make
320 * client handles for the extra addresses.
321 */
322extern struct i2c_client *
323i2c_new_dummy(struct i2c_adapter *adap, u16 address);
324
325extern void i2c_unregister_device(struct i2c_client *);
326#endif /* I2C */
327
328/* Mainboard arch_initcall() code should register all its I2C devices.
329 * This is done at arch_initcall time, before declaring any i2c adapters.
330 * Modules for add-on boards must use other calls.
331 */
332#ifdef CONFIG_I2C_BOARDINFO
333extern int
334i2c_register_board_info(int busnum, struct i2c_board_info const *info,
335 unsigned n);
336#else
337static inline int
338i2c_register_board_info(int busnum, struct i2c_board_info const *info,
339 unsigned n)
340{
341 return 0;
342}
343#endif /* I2C_BOARDINFO */
344
345/**
346 * struct i2c_algorithm - represent I2C transfer method
347 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
348 * defined by the msgs array, with num messages available to transfer via
349 * the adapter specified by adap.
350 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
351 * is not present, then the bus layer will try and convert the SMBus calls
352 * into I2C transfers instead.
353 * @functionality: Return the flags that this algorithm/adapter pair supports
354 * from the I2C_FUNC_* flags.
355 *
356 * The following structs are for those who like to implement new bus drivers:
357 * i2c_algorithm is the interface to a class of hardware solutions which can
358 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
359 * to name two of the most common.
360 *
361 * The return codes from the @master_xfer field should indicate the type of
362 * error code that occured during the transfer, as documented in the kernel
363 * Documentation file Documentation/i2c/fault-codes.
364 */
365struct i2c_algorithm {
366 /* If an adapter algorithm can't do I2C-level access, set master_xfer
367 to NULL. If an adapter algorithm can do SMBus access, set
368 smbus_xfer. If set to NULL, the SMBus protocol is simulated
369 using common I2C messages */
370 /* master_xfer should return the number of messages successfully
371 processed, or a negative value on error */
372 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
373 int num);
374 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
375 unsigned short flags, char read_write,
376 u8 command, int size, union i2c_smbus_data *data);
377
378 /* To determine what the adapter supports */
379 u32 (*functionality) (struct i2c_adapter *);
380};
381
382/**
383 * struct i2c_bus_recovery_info - I2C bus recovery information
384 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
385 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
386 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
387 * recovery. Used internally for generic GPIO recovery.
388 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
389 * internally for generic GPIO recovery.
390 * @get_sda: This gets current value of SDA line. Optional for generic SCL
391 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
392 * recovery.
393 * @prepare_recovery: This will be called before starting recovery. Platform may
394 * configure padmux here for SDA/SCL line or something else they want.
395 * @unprepare_recovery: This will be called after completing recovery. Platform
396 * may configure padmux here for SDA/SCL line or something else they want.
397 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
398 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
399 */
400struct i2c_bus_recovery_info {
401 int (*recover_bus)(struct i2c_adapter *);
402
403 int (*get_scl)(struct i2c_adapter *);
404 void (*set_scl)(struct i2c_adapter *, int val);
405 int (*get_sda)(struct i2c_adapter *);
406
407 void (*prepare_recovery)(struct i2c_bus_recovery_info *bri);
408 void (*unprepare_recovery)(struct i2c_bus_recovery_info *bri);
409
410 /* gpio recovery */
411 int scl_gpio;
412 int sda_gpio;
413};
414
415int i2c_recover_bus(struct i2c_adapter *adap);
416
417/* Generic recovery routines */
418int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
419int i2c_generic_scl_recovery(struct i2c_adapter *adap);
420
421/*
422 * i2c_adapter is the structure used to identify a physical i2c bus along
423 * with the access algorithms necessary to access it.
424 */
425struct i2c_adapter {
426 struct module *owner;
427 unsigned int class; /* classes to allow probing for */
428 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
429 void *algo_data;
430
431 /* data fields that are valid for all devices */
432 struct rt_mutex bus_lock;
433
434 int timeout; /* in jiffies */
435 int retries;
436 struct device dev; /* the adapter device */
437
438 int nr;
439 char name[48];
440 struct completion dev_released;
441
442 struct mutex userspace_clients_lock;
443 struct list_head userspace_clients;
444
445 struct i2c_bus_recovery_info *bus_recovery_info;
446};
447#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
448
449static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
450{
451 return dev_get_drvdata(&dev->dev);
452}
453
454static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
455{
456 dev_set_drvdata(&dev->dev, data);
457}
458
459static inline struct i2c_adapter *
460i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
461{
462#if IS_ENABLED(CONFIG_I2C_MUX)
463 struct device *parent = adapter->dev.parent;
464
465 if (parent != NULL && parent->type == &i2c_adapter_type)
466 return to_i2c_adapter(parent);
467 else
468#endif
469 return NULL;
470}
471
472int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
473
474/* Adapter locking functions, exported for shared pin cases */
475void i2c_lock_adapter(struct i2c_adapter *);
476void i2c_unlock_adapter(struct i2c_adapter *);
477
478/*flags for the client struct: */
479#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
480#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
481 /* Must equal I2C_M_TEN below */
482#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
483#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
484 /* Must match I2C_M_STOP|IGNORE_NAK */
485
486/* i2c adapter classes (bitmask) */
487#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
488#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
489#define I2C_CLASS_SPD (1<<7) /* Memory modules */
490#define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
491
492/* Internal numbers to terminate lists */
493#define I2C_CLIENT_END 0xfffeU
494
495/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
496#define I2C_ADDRS(addr, addrs...) \
497 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
498
499
500/* ----- functions exported by i2c.o */
501
502/* administration...
503 */
504#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
505extern int i2c_add_adapter(struct i2c_adapter *);
506extern void i2c_del_adapter(struct i2c_adapter *);
507extern int i2c_add_numbered_adapter(struct i2c_adapter *);
508
509extern int i2c_register_driver(struct module *, struct i2c_driver *);
510extern void i2c_del_driver(struct i2c_driver *);
511
512/* use a define to avoid include chaining to get THIS_MODULE */
513#define i2c_add_driver(driver) \
514 i2c_register_driver(THIS_MODULE, driver)
515
516extern struct i2c_client *i2c_use_client(struct i2c_client *client);
517extern void i2c_release_client(struct i2c_client *client);
518
519/* call the i2c_client->command() of all attached clients with
520 * the given arguments */
521extern void i2c_clients_command(struct i2c_adapter *adap,
522 unsigned int cmd, void *arg);
523
524extern struct i2c_adapter *i2c_get_adapter(int nr);
525extern void i2c_put_adapter(struct i2c_adapter *adap);
526
527
528/* Return the functionality mask */
529static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
530{
531 return adap->algo->functionality(adap);
532}
533
534/* Return 1 if adapter supports everything we need, 0 if not. */
535static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
536{
537 return (func & i2c_get_functionality(adap)) == func;
538}
539
540/* Return the adapter number for a specific adapter */
541static inline int i2c_adapter_id(struct i2c_adapter *adap)
542{
543 return adap->nr;
544}
545
546/**
547 * module_i2c_driver() - Helper macro for registering a I2C driver
548 * @__i2c_driver: i2c_driver struct
549 *
550 * Helper macro for I2C drivers which do not do anything special in module
551 * init/exit. This eliminates a lot of boilerplate. Each module may only
552 * use this macro once, and calling it replaces module_init() and module_exit()
553 */
554#define module_i2c_driver(__i2c_driver) \
555 module_driver(__i2c_driver, i2c_add_driver, \
556 i2c_del_driver)
557
558#endif /* I2C */
559
560#if IS_ENABLED(CONFIG_OF)
561/* must call put_device() when done with returned i2c_client device */
562extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
563
564/* must call put_device() when done with returned i2c_adapter device */
565extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
566
567#else
568
569static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
570{
571 return NULL;
572}
573
574static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
575{
576 return NULL;
577}
578#endif /* CONFIG_OF */
579
580#endif /* _LINUX_I2C_H */