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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 <[email protected]>
6 *
7 * With some changes from Kyösti Mälkki <[email protected]> and
8 * Frodo Looijaard <[email protected]>
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 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
235 *
236 * The driver.owner field should be set to the module owner of this driver.
237 * The driver.name field should be set to the name of this driver.
238 *
239 * For automatic device detection, both @detect and @address_list must
240 * be defined. @class should also be set, otherwise only devices forced
241 * with module parameters will be created. The detect function must
242 * fill at least the name field of the i2c_board_info structure it is
243 * handed upon successful detection, and possibly also the flags field.
244 *
245 * If @detect is missing, the driver will still work fine for enumerated
246 * devices. Detected devices simply won't be supported. This is expected
247 * for the many I2C/SMBus devices which can't be detected reliably, and
248 * the ones which can always be enumerated in practice.
249 *
250 * The i2c_client structure which is handed to the @detect callback is
251 * not a real i2c_client. It is initialized just enough so that you can
252 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
253 * else with it. In particular, calling dev_dbg and friends on it is
254 * not allowed.
255 */
256struct i2c_driver {
257 unsigned int class;
258
259 /* Standard driver model interfaces */
260 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
261 int (*remove)(struct i2c_client *client);
262
263 /* New driver model interface to aid the seamless removal of the
264 * current probe()'s, more commonly unused than used second parameter.
265 */
266 int (*probe_new)(struct i2c_client *client);
267
268 /* driver model interfaces that don't relate to enumeration */
269 void (*shutdown)(struct i2c_client *client);
270
271 /* Alert callback, for example for the SMBus alert protocol.
272 * The format and meaning of the data value depends on the protocol.
273 * For the SMBus alert protocol, there is a single bit of data passed
274 * as the alert response's low bit ("event flag").
275 * For the SMBus Host Notify protocol, the data corresponds to the
276 * 16-bit payload data reported by the slave device acting as master.
277 */
278 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
279 unsigned int data);
280
281 /* a ioctl like command that can be used to perform specific functions
282 * with the device.
283 */
284 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
285
286 struct device_driver driver;
287 const struct i2c_device_id *id_table;
288
289 /* Device detection callback for automatic device creation */
290 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
291 const unsigned short *address_list;
292 struct list_head clients;
293
294 bool disable_i2c_core_irq_mapping;
295};
296#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
297
298/**
299 * struct i2c_client - represent an I2C slave device
300 * @flags: see I2C_CLIENT_* for possible flags
301 * @addr: Address used on the I2C bus connected to the parent adapter.
302 * @name: Indicates the type of the device, usually a chip name that's
303 * generic enough to hide second-sourcing and compatible revisions.
304 * @adapter: manages the bus segment hosting this I2C device
305 * @dev: Driver model device node for the slave.
306 * @init_irq: IRQ that was set at initialization
307 * @irq: indicates the IRQ generated by this device (if any)
308 * @detected: member of an i2c_driver.clients list or i2c-core's
309 * userspace_devices list
310 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
311 * calls it to pass on slave events to the slave driver.
312 *
313 * An i2c_client identifies a single device (i.e. chip) connected to an
314 * i2c bus. The behaviour exposed to Linux is defined by the driver
315 * managing the device.
316 */
317struct i2c_client {
318 unsigned short flags; /* div., see below */
319#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
320#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
321 /* Must equal I2C_M_TEN below */
322#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
323#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
324#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
325#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
326 /* Must match I2C_M_STOP|IGNORE_NAK */
327
328 unsigned short addr; /* chip address - NOTE: 7bit */
329 /* addresses are stored in the */
330 /* _LOWER_ 7 bits */
331 char name[I2C_NAME_SIZE];
332 struct i2c_adapter *adapter; /* the adapter we sit on */
333 struct device dev; /* the device structure */
334 int init_irq; /* irq set at initialization */
335 int irq; /* irq issued by device */
336 struct list_head detected;
337#if IS_ENABLED(CONFIG_I2C_SLAVE)
338 i2c_slave_cb_t slave_cb; /* callback for slave mode */
339#endif
340};
341#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
342
343struct i2c_client *i2c_verify_client(struct device *dev);
344struct i2c_adapter *i2c_verify_adapter(struct device *dev);
345const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
346 const struct i2c_client *client);
347
348static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
349{
350 struct device * const dev = container_of(kobj, struct device, kobj);
351 return to_i2c_client(dev);
352}
353
354static inline void *i2c_get_clientdata(const struct i2c_client *client)
355{
356 return dev_get_drvdata(&client->dev);
357}
358
359static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
360{
361 dev_set_drvdata(&client->dev, data);
362}
363
364/* I2C slave support */
365
366#if IS_ENABLED(CONFIG_I2C_SLAVE)
367enum i2c_slave_event {
368 I2C_SLAVE_READ_REQUESTED,
369 I2C_SLAVE_WRITE_REQUESTED,
370 I2C_SLAVE_READ_PROCESSED,
371 I2C_SLAVE_WRITE_RECEIVED,
372 I2C_SLAVE_STOP,
373};
374
375int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
376int i2c_slave_unregister(struct i2c_client *client);
377bool i2c_detect_slave_mode(struct device *dev);
378
379static inline int i2c_slave_event(struct i2c_client *client,
380 enum i2c_slave_event event, u8 *val)
381{
382 return client->slave_cb(client, event, val);
383}
384#else
385static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
386#endif
387
388/**
389 * struct i2c_board_info - template for device creation
390 * @type: chip type, to initialize i2c_client.name
391 * @flags: to initialize i2c_client.flags
392 * @addr: stored in i2c_client.addr
393 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
394 * @platform_data: stored in i2c_client.dev.platform_data
395 * @of_node: pointer to OpenFirmware device node
396 * @fwnode: device node supplied by the platform firmware
397 * @properties: additional device properties for the device
398 * @resources: resources associated with the device
399 * @num_resources: number of resources in the @resources array
400 * @irq: stored in i2c_client.irq
401 *
402 * I2C doesn't actually support hardware probing, although controllers and
403 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
404 * a device at a given address. Drivers commonly need more information than
405 * that, such as chip type, configuration, associated IRQ, and so on.
406 *
407 * i2c_board_info is used to build tables of information listing I2C devices
408 * that are present. This information is used to grow the driver model tree.
409 * For mainboards this is done statically using i2c_register_board_info();
410 * bus numbers identify adapters that aren't yet available. For add-on boards,
411 * i2c_new_client_device() does this dynamically with the adapter already known.
412 */
413struct i2c_board_info {
414 char type[I2C_NAME_SIZE];
415 unsigned short flags;
416 unsigned short addr;
417 const char *dev_name;
418 void *platform_data;
419 struct device_node *of_node;
420 struct fwnode_handle *fwnode;
421 const struct property_entry *properties;
422 const struct resource *resources;
423 unsigned int num_resources;
424 int irq;
425};
426
427/**
428 * I2C_BOARD_INFO - macro used to list an i2c device and its address
429 * @dev_type: identifies the device type
430 * @dev_addr: the device's address on the bus.
431 *
432 * This macro initializes essential fields of a struct i2c_board_info,
433 * declaring what has been provided on a particular board. Optional
434 * fields (such as associated irq, or device-specific platform_data)
435 * are provided using conventional syntax.
436 */
437#define I2C_BOARD_INFO(dev_type, dev_addr) \
438 .type = dev_type, .addr = (dev_addr)
439
440
441#if IS_ENABLED(CONFIG_I2C)
442/*
443 * Add-on boards should register/unregister their devices; e.g. a board
444 * with integrated I2C, a config eeprom, sensors, and a codec that's
445 * used in conjunction with the primary hardware.
446 */
447struct i2c_client *
448i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
449
450/* If you don't know the exact address of an I2C device, use this variant
451 * instead, which can probe for device presence in a list of possible
452 * addresses. The "probe" callback function is optional. If it is provided,
453 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
454 * a default probing method is used.
455 */
456struct i2c_client *
457i2c_new_scanned_device(struct i2c_adapter *adap,
458 struct i2c_board_info *info,
459 unsigned short const *addr_list,
460 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
461
462/* Common custom probe functions */
463int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
464
465struct i2c_client *
466i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
467
468struct i2c_client *
469devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
470
471struct i2c_client *
472i2c_new_ancillary_device(struct i2c_client *client,
473 const char *name,
474 u16 default_addr);
475
476void i2c_unregister_device(struct i2c_client *client);
477#endif /* I2C */
478
479/* Mainboard arch_initcall() code should register all its I2C devices.
480 * This is done at arch_initcall time, before declaring any i2c adapters.
481 * Modules for add-on boards must use other calls.
482 */
483#ifdef CONFIG_I2C_BOARDINFO
484int
485i2c_register_board_info(int busnum, struct i2c_board_info const *info,
486 unsigned n);
487#else
488static inline int
489i2c_register_board_info(int busnum, struct i2c_board_info const *info,
490 unsigned n)
491{
492 return 0;
493}
494#endif /* I2C_BOARDINFO */
495
496/**
497 * struct i2c_algorithm - represent I2C transfer method
498 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
499 * defined by the msgs array, with num messages available to transfer via
500 * the adapter specified by adap.
501 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
502 * so e.g. PMICs can be accessed very late before shutdown. Optional.
503 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
504 * is not present, then the bus layer will try and convert the SMBus calls
505 * into I2C transfers instead.
506 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
507 * so e.g. PMICs can be accessed very late before shutdown. Optional.
508 * @functionality: Return the flags that this algorithm/adapter pair supports
509 * from the ``I2C_FUNC_*`` flags.
510 * @reg_slave: Register given client to I2C slave mode of this adapter
511 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
512 *
513 * The following structs are for those who like to implement new bus drivers:
514 * i2c_algorithm is the interface to a class of hardware solutions which can
515 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
516 * to name two of the most common.
517 *
518 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
519 * type of error code that occurred during the transfer, as documented in the
520 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
521 */
522struct i2c_algorithm {
523 /*
524 * If an adapter algorithm can't do I2C-level access, set master_xfer
525 * to NULL. If an adapter algorithm can do SMBus access, set
526 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
527 * using common I2C messages.
528 *
529 * master_xfer should return the number of messages successfully
530 * processed, or a negative value on error
531 */
532 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
533 int num);
534 int (*master_xfer_atomic)(struct i2c_adapter *adap,
535 struct i2c_msg *msgs, int num);
536 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
537 unsigned short flags, char read_write,
538 u8 command, int size, union i2c_smbus_data *data);
539 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
540 unsigned short flags, char read_write,
541 u8 command, int size, union i2c_smbus_data *data);
542
543 /* To determine what the adapter supports */
544 u32 (*functionality)(struct i2c_adapter *adap);
545
546#if IS_ENABLED(CONFIG_I2C_SLAVE)
547 int (*reg_slave)(struct i2c_client *client);
548 int (*unreg_slave)(struct i2c_client *client);
549#endif
550};
551
552/**
553 * struct i2c_lock_operations - represent I2C locking operations
554 * @lock_bus: Get exclusive access to an I2C bus segment
555 * @trylock_bus: Try to get exclusive access to an I2C bus segment
556 * @unlock_bus: Release exclusive access to an I2C bus segment
557 *
558 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
559 */
560struct i2c_lock_operations {
561 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
562 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
563 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
564};
565
566/**
567 * struct i2c_timings - I2C timing information
568 * @bus_freq_hz: the bus frequency in Hz
569 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
570 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
571 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
572 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
573 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
574 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
575 * digital filter can filter out
576 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
577 * analog filter
578 */
579struct i2c_timings {
580 u32 bus_freq_hz;
581 u32 scl_rise_ns;
582 u32 scl_fall_ns;
583 u32 scl_int_delay_ns;
584 u32 sda_fall_ns;
585 u32 sda_hold_ns;
586 u32 digital_filter_width_ns;
587 u32 analog_filter_cutoff_freq_hz;
588};
589
590/**
591 * struct i2c_bus_recovery_info - I2C bus recovery information
592 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
593 * i2c_generic_scl_recovery().
594 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
595 * recovery. Populated internally for generic GPIO recovery.
596 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
597 * Populated internally for generic GPIO recovery.
598 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
599 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
600 * GPIO, for generic GPIO recovery.
601 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
602 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
603 * for generic GPIO recovery.
604 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
605 * has a more complex internal logic than just reading SDA. Optional.
606 * @prepare_recovery: This will be called before starting recovery. Platform may
607 * configure padmux here for SDA/SCL line or something else they want.
608 * @unprepare_recovery: This will be called after completing recovery. Platform
609 * may configure padmux here for SDA/SCL line or something else they want.
610 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
611 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
612 */
613struct i2c_bus_recovery_info {
614 int (*recover_bus)(struct i2c_adapter *adap);
615
616 int (*get_scl)(struct i2c_adapter *adap);
617 void (*set_scl)(struct i2c_adapter *adap, int val);
618 int (*get_sda)(struct i2c_adapter *adap);
619 void (*set_sda)(struct i2c_adapter *adap, int val);
620 int (*get_bus_free)(struct i2c_adapter *adap);
621
622 void (*prepare_recovery)(struct i2c_adapter *adap);
623 void (*unprepare_recovery)(struct i2c_adapter *adap);
624
625 /* gpio recovery */
626 struct gpio_desc *scl_gpiod;
627 struct gpio_desc *sda_gpiod;
628};
629
630int i2c_recover_bus(struct i2c_adapter *adap);
631
632/* Generic recovery routines */
633int i2c_generic_scl_recovery(struct i2c_adapter *adap);
634
635/**
636 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
637 * @flags: see I2C_AQ_* for possible flags and read below
638 * @max_num_msgs: maximum number of messages per transfer
639 * @max_write_len: maximum length of a write message
640 * @max_read_len: maximum length of a read message
641 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
642 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
643 *
644 * Note about combined messages: Some I2C controllers can only send one message
645 * per transfer, plus something called combined message or write-then-read.
646 * This is (usually) a small write message followed by a read message and
647 * barely enough to access register based devices like EEPROMs. There is a flag
648 * to support this mode. It implies max_num_msg = 2 and does the length checks
649 * with max_comb_*_len because combined message mode usually has its own
650 * limitations. Because of HW implementations, some controllers can actually do
651 * write-then-anything or other variants. To support that, write-then-read has
652 * been broken out into smaller bits like write-first and read-second which can
653 * be combined as needed.
654 */
655
656struct i2c_adapter_quirks {
657 u64 flags;
658 int max_num_msgs;
659 u16 max_write_len;
660 u16 max_read_len;
661 u16 max_comb_1st_msg_len;
662 u16 max_comb_2nd_msg_len;
663};
664
665/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
666#define I2C_AQ_COMB BIT(0)
667/* first combined message must be write */
668#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
669/* second combined message must be read */
670#define I2C_AQ_COMB_READ_SECOND BIT(2)
671/* both combined messages must have the same target address */
672#define I2C_AQ_COMB_SAME_ADDR BIT(3)
673/* convenience macro for typical write-then read case */
674#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
675 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
676/* clock stretching is not supported */
677#define I2C_AQ_NO_CLK_STRETCH BIT(4)
678/* message cannot have length of 0 */
679#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
680#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
681#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
682
683/*
684 * i2c_adapter is the structure used to identify a physical i2c bus along
685 * with the access algorithms necessary to access it.
686 */
687struct i2c_adapter {
688 struct module *owner;
689 unsigned int class; /* classes to allow probing for */
690 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
691 void *algo_data;
692
693 /* data fields that are valid for all devices */
694 const struct i2c_lock_operations *lock_ops;
695 struct rt_mutex bus_lock;
696 struct rt_mutex mux_lock;
697
698 int timeout; /* in jiffies */
699 int retries;
700 struct device dev; /* the adapter device */
701 unsigned long locked_flags; /* owned by the I2C core */
702#define I2C_ALF_IS_SUSPENDED 0
703#define I2C_ALF_SUSPEND_REPORTED 1
704
705 int nr;
706 char name[48];
707 struct completion dev_released;
708
709 struct mutex userspace_clients_lock;
710 struct list_head userspace_clients;
711
712 struct i2c_bus_recovery_info *bus_recovery_info;
713 const struct i2c_adapter_quirks *quirks;
714
715 struct irq_domain *host_notify_domain;
716};
717#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
718
719static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
720{
721 return dev_get_drvdata(&adap->dev);
722}
723
724static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
725{
726 dev_set_drvdata(&adap->dev, data);
727}
728
729static inline struct i2c_adapter *
730i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
731{
732#if IS_ENABLED(CONFIG_I2C_MUX)
733 struct device *parent = adapter->dev.parent;
734
735 if (parent != NULL && parent->type == &i2c_adapter_type)
736 return to_i2c_adapter(parent);
737 else
738#endif
739 return NULL;
740}
741
742int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
743
744/* Adapter locking functions, exported for shared pin cases */
745#define I2C_LOCK_ROOT_ADAPTER BIT(0)
746#define I2C_LOCK_SEGMENT BIT(1)
747
748/**
749 * i2c_lock_bus - Get exclusive access to an I2C bus segment
750 * @adapter: Target I2C bus segment
751 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
752 * locks only this branch in the adapter tree
753 */
754static inline void
755i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
756{
757 adapter->lock_ops->lock_bus(adapter, flags);
758}
759
760/**
761 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
762 * @adapter: Target I2C bus segment
763 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
764 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
765 *
766 * Return: true if the I2C bus segment is locked, false otherwise
767 */
768static inline int
769i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
770{
771 return adapter->lock_ops->trylock_bus(adapter, flags);
772}
773
774/**
775 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
776 * @adapter: Target I2C bus segment
777 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
778 * unlocks only this branch in the adapter tree
779 */
780static inline void
781i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
782{
783 adapter->lock_ops->unlock_bus(adapter, flags);
784}
785
786/**
787 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
788 * @adap: Adapter to mark as suspended
789 *
790 * When using this helper to mark an adapter as suspended, the core will reject
791 * further transfers to this adapter. The usage of this helper is optional but
792 * recommended for devices having distinct handlers for system suspend and
793 * runtime suspend. More complex devices are free to implement custom solutions
794 * to reject transfers when suspended.
795 */
796static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
797{
798 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
799 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
800 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
801}
802
803/**
804 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
805 * @adap: Adapter to mark as resumed
806 *
807 * When using this helper to mark an adapter as resumed, the core will allow
808 * further transfers to this adapter. See also further notes to
809 * @i2c_mark_adapter_suspended().
810 */
811static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
812{
813 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
814 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
815 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
816}
817
818/* i2c adapter classes (bitmask) */
819#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
820#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
821#define I2C_CLASS_SPD (1<<7) /* Memory modules */
822/* Warn users that the adapter doesn't support classes anymore */
823#define I2C_CLASS_DEPRECATED (1<<8)
824
825/* Internal numbers to terminate lists */
826#define I2C_CLIENT_END 0xfffeU
827
828/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
829#define I2C_ADDRS(addr, addrs...) \
830 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
831
832
833/* ----- functions exported by i2c.o */
834
835/* administration...
836 */
837#if IS_ENABLED(CONFIG_I2C)
838int i2c_add_adapter(struct i2c_adapter *adap);
839void i2c_del_adapter(struct i2c_adapter *adap);
840int i2c_add_numbered_adapter(struct i2c_adapter *adap);
841
842int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
843void i2c_del_driver(struct i2c_driver *driver);
844
845/* use a define to avoid include chaining to get THIS_MODULE */
846#define i2c_add_driver(driver) \
847 i2c_register_driver(THIS_MODULE, driver)
848
849static inline bool i2c_client_has_driver(struct i2c_client *client)
850{
851 return !IS_ERR_OR_NULL(client) && client->dev.driver;
852}
853
854/* call the i2c_client->command() of all attached clients with
855 * the given arguments */
856void i2c_clients_command(struct i2c_adapter *adap,
857 unsigned int cmd, void *arg);
858
859struct i2c_adapter *i2c_get_adapter(int nr);
860void i2c_put_adapter(struct i2c_adapter *adap);
861unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
862
863void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
864
865/* Return the functionality mask */
866static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
867{
868 return adap->algo->functionality(adap);
869}
870
871/* Return 1 if adapter supports everything we need, 0 if not. */
872static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
873{
874 return (func & i2c_get_functionality(adap)) == func;
875}
876
877/**
878 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
879 * @adap: i2c adapter
880 * @quirks: quirk flags
881 *
882 * Return: true if the adapter has all the specified quirk flags, false if not
883 */
884static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
885{
886 if (!adap->quirks)
887 return false;
888 return (adap->quirks->flags & quirks) == quirks;
889}
890
891/* Return the adapter number for a specific adapter */
892static inline int i2c_adapter_id(struct i2c_adapter *adap)
893{
894 return adap->nr;
895}
896
897static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
898{
899 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
900}
901
902u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
903void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
904
905int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
906/**
907 * module_i2c_driver() - Helper macro for registering a modular I2C driver
908 * @__i2c_driver: i2c_driver struct
909 *
910 * Helper macro for I2C drivers which do not do anything special in module
911 * init/exit. This eliminates a lot of boilerplate. Each module may only
912 * use this macro once, and calling it replaces module_init() and module_exit()
913 */
914#define module_i2c_driver(__i2c_driver) \
915 module_driver(__i2c_driver, i2c_add_driver, \
916 i2c_del_driver)
917
918/**
919 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
920 * @__i2c_driver: i2c_driver struct
921 *
922 * Helper macro for I2C drivers which do not do anything special in their
923 * init. This eliminates a lot of boilerplate. Each driver may only
924 * use this macro once, and calling it replaces device_initcall().
925 */
926#define builtin_i2c_driver(__i2c_driver) \
927 builtin_driver(__i2c_driver, i2c_add_driver)
928
929#endif /* I2C */
930
931#if IS_ENABLED(CONFIG_OF)
932/* must call put_device() when done with returned i2c_client device */
933struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
934
935/* must call put_device() when done with returned i2c_adapter device */
936struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
937
938/* must call i2c_put_adapter() when done with returned i2c_adapter device */
939struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
940
941const struct of_device_id
942*i2c_of_match_device(const struct of_device_id *matches,
943 struct i2c_client *client);
944
945int of_i2c_get_board_info(struct device *dev, struct device_node *node,
946 struct i2c_board_info *info);
947
948#else
949
950static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
951{
952 return NULL;
953}
954
955static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
956{
957 return NULL;
958}
959
960static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
961{
962 return NULL;
963}
964
965static inline const struct of_device_id
966*i2c_of_match_device(const struct of_device_id *matches,
967 struct i2c_client *client)
968{
969 return NULL;
970}
971
972static inline int of_i2c_get_board_info(struct device *dev,
973 struct device_node *node,
974 struct i2c_board_info *info)
975{
976 return -ENOTSUPP;
977}
978
979#endif /* CONFIG_OF */
980
981struct acpi_resource;
982struct acpi_resource_i2c_serialbus;
983
984#if IS_ENABLED(CONFIG_ACPI)
985bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
986 struct acpi_resource_i2c_serialbus **i2c);
987u32 i2c_acpi_find_bus_speed(struct device *dev);
988struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
989 struct i2c_board_info *info);
990struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
991#else
992static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
993 struct acpi_resource_i2c_serialbus **i2c)
994{
995 return false;
996}
997static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
998{
999 return 0;
1000}
1001static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1002 int index, struct i2c_board_info *info)
1003{
1004 return ERR_PTR(-ENODEV);
1005}
1006static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1007{
1008 return NULL;
1009}
1010#endif /* CONFIG_ACPI */
1011
1012#endif /* _LINUX_I2C_H */