Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-or-later */
2 : /*
3 : * i2c.h - definitions for the Linux i2c bus interface
4 : * Copyright (C) 1995-2000 Simon G. Vogl
5 : * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org>
6 : *
7 : * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
8 : * Frodo Looijaard <frodol@dds.nl>
9 : */
10 : #ifndef _LINUX_I2C_H
11 : #define _LINUX_I2C_H
12 :
13 : #include <linux/acpi.h> /* for acpi_handle */
14 : #include <linux/bits.h>
15 : #include <linux/mod_devicetable.h>
16 : #include <linux/device.h> /* for struct device */
17 : #include <linux/sched.h> /* for completion */
18 : #include <linux/mutex.h>
19 : #include <linux/regulator/consumer.h>
20 : #include <linux/rtmutex.h>
21 : #include <linux/irqdomain.h> /* for Host Notify IRQ */
22 : #include <linux/of.h> /* for struct device_node */
23 : #include <linux/swab.h> /* for swab16 */
24 : #include <uapi/linux/i2c.h>
25 :
26 : extern struct bus_type i2c_bus_type;
27 : extern struct device_type i2c_adapter_type;
28 : extern struct device_type i2c_client_type;
29 :
30 : /* --- General options ------------------------------------------------ */
31 :
32 : struct i2c_msg;
33 : struct i2c_algorithm;
34 : struct i2c_adapter;
35 : struct i2c_client;
36 : struct i2c_driver;
37 : struct i2c_device_identity;
38 : union i2c_smbus_data;
39 : struct i2c_board_info;
40 : enum i2c_slave_event;
41 : typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
42 : enum i2c_slave_event event, u8 *val);
43 :
44 : /* I2C Frequency Modes */
45 : #define I2C_MAX_STANDARD_MODE_FREQ 100000
46 : #define I2C_MAX_FAST_MODE_FREQ 400000
47 : #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
48 : #define I2C_MAX_TURBO_MODE_FREQ 1400000
49 : #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
50 : #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
51 :
52 : struct module;
53 : struct property_entry;
54 :
55 : #if IS_ENABLED(CONFIG_I2C)
56 : /* Return the Frequency mode string based on the bus frequency */
57 : const char *i2c_freq_mode_string(u32 bus_freq_hz);
58 :
59 : /*
60 : * The master routines are the ones normally used to transmit data to devices
61 : * on a bus (or read from them). Apart from two basic transfer functions to
62 : * transmit one message at a time, a more complex version can be used to
63 : * transmit an arbitrary number of messages without interruption.
64 : * @count must be less than 64k since msg.len is u16.
65 : */
66 : int i2c_transfer_buffer_flags(const struct i2c_client *client,
67 : char *buf, int count, u16 flags);
68 :
69 : /**
70 : * i2c_master_recv - issue a single I2C message in master receive mode
71 : * @client: Handle to slave device
72 : * @buf: Where to store data read from slave
73 : * @count: How many bytes to read, must be less than 64k since msg.len is u16
74 : *
75 : * Returns negative errno, or else the number of bytes read.
76 : */
77 : static inline int i2c_master_recv(const struct i2c_client *client,
78 : char *buf, int count)
79 : {
80 : return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
81 : };
82 :
83 : /**
84 : * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
85 : * using a DMA safe buffer
86 : * @client: Handle to slave device
87 : * @buf: Where to store data read from slave, must be safe to use with DMA
88 : * @count: How many bytes to read, must be less than 64k since msg.len is u16
89 : *
90 : * Returns negative errno, or else the number of bytes read.
91 : */
92 : static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
93 : char *buf, int count)
94 : {
95 : return i2c_transfer_buffer_flags(client, buf, count,
96 : I2C_M_RD | I2C_M_DMA_SAFE);
97 : };
98 :
99 : /**
100 : * i2c_master_send - issue a single I2C message in master transmit mode
101 : * @client: Handle to slave device
102 : * @buf: Data that will be written to the slave
103 : * @count: How many bytes to write, must be less than 64k since msg.len is u16
104 : *
105 : * Returns negative errno, or else the number of bytes written.
106 : */
107 : static inline int i2c_master_send(const struct i2c_client *client,
108 : const char *buf, int count)
109 : {
110 : return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
111 : };
112 :
113 : /**
114 : * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
115 : * using a DMA safe buffer
116 : * @client: Handle to slave device
117 : * @buf: Data that will be written to the slave, must be safe to use with DMA
118 : * @count: How many bytes to write, must be less than 64k since msg.len is u16
119 : *
120 : * Returns negative errno, or else the number of bytes written.
121 : */
122 : static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
123 : const char *buf, int count)
124 : {
125 : return i2c_transfer_buffer_flags(client, (char *)buf, count,
126 : I2C_M_DMA_SAFE);
127 : };
128 :
129 : /* Transfer num messages.
130 : */
131 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
132 : /* Unlocked flavor */
133 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
134 :
135 : /* This is the very generalized SMBus access routine. You probably do not
136 : want to use this, though; one of the functions below may be much easier,
137 : and probably just as fast.
138 : Note that we use i2c_adapter here, because you do not need a specific
139 : smbus adapter to call this function. */
140 : s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
141 : unsigned short flags, char read_write, u8 command,
142 : int protocol, union i2c_smbus_data *data);
143 :
144 : /* Unlocked flavor */
145 : s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
146 : unsigned short flags, char read_write, u8 command,
147 : int protocol, union i2c_smbus_data *data);
148 :
149 : /* Now follow the 'nice' access routines. These also document the calling
150 : conventions of i2c_smbus_xfer. */
151 :
152 : u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
153 : s32 i2c_smbus_read_byte(const struct i2c_client *client);
154 : s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
155 : s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
156 : s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
157 : u8 command, u8 value);
158 : s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
159 : s32 i2c_smbus_write_word_data(const struct i2c_client *client,
160 : u8 command, u16 value);
161 :
162 : static inline s32
163 : i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
164 : {
165 : s32 value = i2c_smbus_read_word_data(client, command);
166 :
167 : return (value < 0) ? value : swab16(value);
168 : }
169 :
170 : static inline s32
171 : i2c_smbus_write_word_swapped(const struct i2c_client *client,
172 : u8 command, u16 value)
173 : {
174 : return i2c_smbus_write_word_data(client, command, swab16(value));
175 : }
176 :
177 : /* Returns the number of read bytes */
178 : s32 i2c_smbus_read_block_data(const struct i2c_client *client,
179 : u8 command, u8 *values);
180 : s32 i2c_smbus_write_block_data(const struct i2c_client *client,
181 : u8 command, u8 length, const u8 *values);
182 : /* Returns the number of read bytes */
183 : s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
184 : u8 command, u8 length, u8 *values);
185 : s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
186 : u8 command, u8 length, const u8 *values);
187 : s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
188 : u8 command, u8 length,
189 : u8 *values);
190 : int i2c_get_device_id(const struct i2c_client *client,
191 : struct i2c_device_identity *id);
192 : #endif /* I2C */
193 :
194 : /**
195 : * struct i2c_device_identity - i2c client device identification
196 : * @manufacturer_id: 0 - 4095, database maintained by NXP
197 : * @part_id: 0 - 511, according to manufacturer
198 : * @die_revision: 0 - 7, according to manufacturer
199 : */
200 : struct i2c_device_identity {
201 : u16 manufacturer_id;
202 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
203 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
204 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
205 : #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
206 : #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
207 : #define I2C_DEVICE_ID_ANALOG_DEVICES 5
208 : #define I2C_DEVICE_ID_STMICROELECTRONICS 6
209 : #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
210 : #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
211 : #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
212 : #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
213 : #define I2C_DEVICE_ID_FLIR 11
214 : #define I2C_DEVICE_ID_O2MICRO 12
215 : #define I2C_DEVICE_ID_ATMEL 13
216 : #define I2C_DEVICE_ID_NONE 0xffff
217 : u16 part_id;
218 : u8 die_revision;
219 : };
220 :
221 : enum i2c_alert_protocol {
222 : I2C_PROTOCOL_SMBUS_ALERT,
223 : I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
224 : };
225 :
226 : /**
227 : * enum i2c_driver_flags - Flags for an I2C device driver
228 : *
229 : * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe
230 : */
231 : enum i2c_driver_flags {
232 : I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0),
233 : };
234 :
235 : /**
236 : * struct i2c_driver - represent an I2C device driver
237 : * @class: What kind of i2c device we instantiate (for detect)
238 : * @probe: Callback for device binding - soon to be deprecated
239 : * @probe_new: New callback for device binding
240 : * @remove: Callback for device unbinding
241 : * @shutdown: Callback for device shutdown
242 : * @alert: Alert callback, for example for the SMBus alert protocol
243 : * @command: Callback for bus-wide signaling (optional)
244 : * @driver: Device driver model driver
245 : * @id_table: List of I2C devices supported by this driver
246 : * @detect: Callback for device detection
247 : * @address_list: The I2C addresses to probe (for detect)
248 : * @clients: List of detected clients we created (for i2c-core use only)
249 : * @flags: A bitmask of flags defined in &enum i2c_driver_flags
250 : *
251 : * The driver.owner field should be set to the module owner of this driver.
252 : * The driver.name field should be set to the name of this driver.
253 : *
254 : * For automatic device detection, both @detect and @address_list must
255 : * be defined. @class should also be set, otherwise only devices forced
256 : * with module parameters will be created. The detect function must
257 : * fill at least the name field of the i2c_board_info structure it is
258 : * handed upon successful detection, and possibly also the flags field.
259 : *
260 : * If @detect is missing, the driver will still work fine for enumerated
261 : * devices. Detected devices simply won't be supported. This is expected
262 : * for the many I2C/SMBus devices which can't be detected reliably, and
263 : * the ones which can always be enumerated in practice.
264 : *
265 : * The i2c_client structure which is handed to the @detect callback is
266 : * not a real i2c_client. It is initialized just enough so that you can
267 : * call i2c_smbus_read_byte_data and friends on it. Don't do anything
268 : * else with it. In particular, calling dev_dbg and friends on it is
269 : * not allowed.
270 : */
271 : struct i2c_driver {
272 : unsigned int class;
273 :
274 : /* Standard driver model interfaces */
275 : int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
276 : int (*remove)(struct i2c_client *client);
277 :
278 : /* New driver model interface to aid the seamless removal of the
279 : * current probe()'s, more commonly unused than used second parameter.
280 : */
281 : int (*probe_new)(struct i2c_client *client);
282 :
283 : /* driver model interfaces that don't relate to enumeration */
284 : void (*shutdown)(struct i2c_client *client);
285 :
286 : /* Alert callback, for example for the SMBus alert protocol.
287 : * The format and meaning of the data value depends on the protocol.
288 : * For the SMBus alert protocol, there is a single bit of data passed
289 : * as the alert response's low bit ("event flag").
290 : * For the SMBus Host Notify protocol, the data corresponds to the
291 : * 16-bit payload data reported by the slave device acting as master.
292 : */
293 : void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
294 : unsigned int data);
295 :
296 : /* a ioctl like command that can be used to perform specific functions
297 : * with the device.
298 : */
299 : int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
300 :
301 : struct device_driver driver;
302 : const struct i2c_device_id *id_table;
303 :
304 : /* Device detection callback for automatic device creation */
305 : int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
306 : const unsigned short *address_list;
307 : struct list_head clients;
308 :
309 : u32 flags;
310 : };
311 : #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
312 :
313 : /**
314 : * struct i2c_client - represent an I2C slave device
315 : * @flags: see I2C_CLIENT_* for possible flags
316 : * @addr: Address used on the I2C bus connected to the parent adapter.
317 : * @name: Indicates the type of the device, usually a chip name that's
318 : * generic enough to hide second-sourcing and compatible revisions.
319 : * @adapter: manages the bus segment hosting this I2C device
320 : * @dev: Driver model device node for the slave.
321 : * @init_irq: IRQ that was set at initialization
322 : * @irq: indicates the IRQ generated by this device (if any)
323 : * @detected: member of an i2c_driver.clients list or i2c-core's
324 : * userspace_devices list
325 : * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
326 : * calls it to pass on slave events to the slave driver.
327 : * @devres_group_id: id of the devres group that will be created for resources
328 : * acquired when probing this device.
329 : *
330 : * An i2c_client identifies a single device (i.e. chip) connected to an
331 : * i2c bus. The behaviour exposed to Linux is defined by the driver
332 : * managing the device.
333 : */
334 : struct i2c_client {
335 : unsigned short flags; /* div., see below */
336 : #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
337 : #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
338 : /* Must equal I2C_M_TEN below */
339 : #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
340 : #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
341 : #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
342 : #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
343 : /* Must match I2C_M_STOP|IGNORE_NAK */
344 :
345 : unsigned short addr; /* chip address - NOTE: 7bit */
346 : /* addresses are stored in the */
347 : /* _LOWER_ 7 bits */
348 : char name[I2C_NAME_SIZE];
349 : struct i2c_adapter *adapter; /* the adapter we sit on */
350 : struct device dev; /* the device structure */
351 : int init_irq; /* irq set at initialization */
352 : int irq; /* irq issued by device */
353 : struct list_head detected;
354 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
355 : i2c_slave_cb_t slave_cb; /* callback for slave mode */
356 : #endif
357 : void *devres_group_id; /* ID of probe devres group */
358 : };
359 : #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
360 :
361 : struct i2c_adapter *i2c_verify_adapter(struct device *dev);
362 : const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
363 : const struct i2c_client *client);
364 :
365 : static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
366 : {
367 : struct device * const dev = kobj_to_dev(kobj);
368 : return to_i2c_client(dev);
369 : }
370 :
371 : static inline void *i2c_get_clientdata(const struct i2c_client *client)
372 : {
373 : return dev_get_drvdata(&client->dev);
374 : }
375 :
376 : static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
377 : {
378 : dev_set_drvdata(&client->dev, data);
379 : }
380 :
381 : /* I2C slave support */
382 :
383 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
384 : enum i2c_slave_event {
385 : I2C_SLAVE_READ_REQUESTED,
386 : I2C_SLAVE_WRITE_REQUESTED,
387 : I2C_SLAVE_READ_PROCESSED,
388 : I2C_SLAVE_WRITE_RECEIVED,
389 : I2C_SLAVE_STOP,
390 : };
391 :
392 : int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
393 : int i2c_slave_unregister(struct i2c_client *client);
394 : bool i2c_detect_slave_mode(struct device *dev);
395 : int i2c_slave_event(struct i2c_client *client,
396 : enum i2c_slave_event event, u8 *val);
397 : #else
398 : static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
399 : #endif
400 :
401 : /**
402 : * struct i2c_board_info - template for device creation
403 : * @type: chip type, to initialize i2c_client.name
404 : * @flags: to initialize i2c_client.flags
405 : * @addr: stored in i2c_client.addr
406 : * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
407 : * @platform_data: stored in i2c_client.dev.platform_data
408 : * @of_node: pointer to OpenFirmware device node
409 : * @fwnode: device node supplied by the platform firmware
410 : * @swnode: software node for the device
411 : * @resources: resources associated with the device
412 : * @num_resources: number of resources in the @resources array
413 : * @irq: stored in i2c_client.irq
414 : *
415 : * I2C doesn't actually support hardware probing, although controllers and
416 : * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
417 : * a device at a given address. Drivers commonly need more information than
418 : * that, such as chip type, configuration, associated IRQ, and so on.
419 : *
420 : * i2c_board_info is used to build tables of information listing I2C devices
421 : * that are present. This information is used to grow the driver model tree.
422 : * For mainboards this is done statically using i2c_register_board_info();
423 : * bus numbers identify adapters that aren't yet available. For add-on boards,
424 : * i2c_new_client_device() does this dynamically with the adapter already known.
425 : */
426 : struct i2c_board_info {
427 : char type[I2C_NAME_SIZE];
428 : unsigned short flags;
429 : unsigned short addr;
430 : const char *dev_name;
431 : void *platform_data;
432 : struct device_node *of_node;
433 : struct fwnode_handle *fwnode;
434 : const struct software_node *swnode;
435 : const struct resource *resources;
436 : unsigned int num_resources;
437 : int irq;
438 : };
439 :
440 : /**
441 : * I2C_BOARD_INFO - macro used to list an i2c device and its address
442 : * @dev_type: identifies the device type
443 : * @dev_addr: the device's address on the bus.
444 : *
445 : * This macro initializes essential fields of a struct i2c_board_info,
446 : * declaring what has been provided on a particular board. Optional
447 : * fields (such as associated irq, or device-specific platform_data)
448 : * are provided using conventional syntax.
449 : */
450 : #define I2C_BOARD_INFO(dev_type, dev_addr) \
451 : .type = dev_type, .addr = (dev_addr)
452 :
453 :
454 : #if IS_ENABLED(CONFIG_I2C)
455 : /*
456 : * Add-on boards should register/unregister their devices; e.g. a board
457 : * with integrated I2C, a config eeprom, sensors, and a codec that's
458 : * used in conjunction with the primary hardware.
459 : */
460 : struct i2c_client *
461 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
462 :
463 : /* If you don't know the exact address of an I2C device, use this variant
464 : * instead, which can probe for device presence in a list of possible
465 : * addresses. The "probe" callback function is optional. If it is provided,
466 : * it must return 1 on successful probe, 0 otherwise. If it is not provided,
467 : * a default probing method is used.
468 : */
469 : struct i2c_client *
470 : i2c_new_scanned_device(struct i2c_adapter *adap,
471 : struct i2c_board_info *info,
472 : unsigned short const *addr_list,
473 : int (*probe)(struct i2c_adapter *adap, unsigned short addr));
474 :
475 : /* Common custom probe functions */
476 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
477 :
478 : struct i2c_client *
479 : i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
480 :
481 : struct i2c_client *
482 : devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
483 :
484 : struct i2c_client *
485 : i2c_new_ancillary_device(struct i2c_client *client,
486 : const char *name,
487 : u16 default_addr);
488 :
489 : void i2c_unregister_device(struct i2c_client *client);
490 :
491 : struct i2c_client *i2c_verify_client(struct device *dev);
492 : #else
493 : static inline struct i2c_client *i2c_verify_client(struct device *dev)
494 : {
495 : return NULL;
496 : }
497 : #endif /* I2C */
498 :
499 : /* Mainboard arch_initcall() code should register all its I2C devices.
500 : * This is done at arch_initcall time, before declaring any i2c adapters.
501 : * Modules for add-on boards must use other calls.
502 : */
503 : #ifdef CONFIG_I2C_BOARDINFO
504 : int
505 : i2c_register_board_info(int busnum, struct i2c_board_info const *info,
506 : unsigned n);
507 : #else
508 : static inline int
509 : i2c_register_board_info(int busnum, struct i2c_board_info const *info,
510 : unsigned n)
511 : {
512 : return 0;
513 : }
514 : #endif /* I2C_BOARDINFO */
515 :
516 : /**
517 : * struct i2c_algorithm - represent I2C transfer method
518 : * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
519 : * defined by the msgs array, with num messages available to transfer via
520 : * the adapter specified by adap.
521 : * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
522 : * so e.g. PMICs can be accessed very late before shutdown. Optional.
523 : * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
524 : * is not present, then the bus layer will try and convert the SMBus calls
525 : * into I2C transfers instead.
526 : * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
527 : * so e.g. PMICs can be accessed very late before shutdown. Optional.
528 : * @functionality: Return the flags that this algorithm/adapter pair supports
529 : * from the ``I2C_FUNC_*`` flags.
530 : * @reg_slave: Register given client to I2C slave mode of this adapter
531 : * @unreg_slave: Unregister given client from I2C slave mode of this adapter
532 : *
533 : * The following structs are for those who like to implement new bus drivers:
534 : * i2c_algorithm is the interface to a class of hardware solutions which can
535 : * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
536 : * to name two of the most common.
537 : *
538 : * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
539 : * type of error code that occurred during the transfer, as documented in the
540 : * Kernel Documentation file Documentation/i2c/fault-codes.rst.
541 : */
542 : struct i2c_algorithm {
543 : /*
544 : * If an adapter algorithm can't do I2C-level access, set master_xfer
545 : * to NULL. If an adapter algorithm can do SMBus access, set
546 : * smbus_xfer. If set to NULL, the SMBus protocol is simulated
547 : * using common I2C messages.
548 : *
549 : * master_xfer should return the number of messages successfully
550 : * processed, or a negative value on error
551 : */
552 : int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
553 : int num);
554 : int (*master_xfer_atomic)(struct i2c_adapter *adap,
555 : struct i2c_msg *msgs, int num);
556 : int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
557 : unsigned short flags, char read_write,
558 : u8 command, int size, union i2c_smbus_data *data);
559 : int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
560 : unsigned short flags, char read_write,
561 : u8 command, int size, union i2c_smbus_data *data);
562 :
563 : /* To determine what the adapter supports */
564 : u32 (*functionality)(struct i2c_adapter *adap);
565 :
566 : #if IS_ENABLED(CONFIG_I2C_SLAVE)
567 : int (*reg_slave)(struct i2c_client *client);
568 : int (*unreg_slave)(struct i2c_client *client);
569 : #endif
570 : };
571 :
572 : /**
573 : * struct i2c_lock_operations - represent I2C locking operations
574 : * @lock_bus: Get exclusive access to an I2C bus segment
575 : * @trylock_bus: Try to get exclusive access to an I2C bus segment
576 : * @unlock_bus: Release exclusive access to an I2C bus segment
577 : *
578 : * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
579 : */
580 : struct i2c_lock_operations {
581 : void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
582 : int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
583 : void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
584 : };
585 :
586 : /**
587 : * struct i2c_timings - I2C timing information
588 : * @bus_freq_hz: the bus frequency in Hz
589 : * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
590 : * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
591 : * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
592 : * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
593 : * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
594 : * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
595 : * digital filter can filter out
596 : * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
597 : * analog filter
598 : */
599 : struct i2c_timings {
600 : u32 bus_freq_hz;
601 : u32 scl_rise_ns;
602 : u32 scl_fall_ns;
603 : u32 scl_int_delay_ns;
604 : u32 sda_fall_ns;
605 : u32 sda_hold_ns;
606 : u32 digital_filter_width_ns;
607 : u32 analog_filter_cutoff_freq_hz;
608 : };
609 :
610 : /**
611 : * struct i2c_bus_recovery_info - I2C bus recovery information
612 : * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
613 : * i2c_generic_scl_recovery().
614 : * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
615 : * recovery. Populated internally for generic GPIO recovery.
616 : * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
617 : * Populated internally for generic GPIO recovery.
618 : * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
619 : * for generic SCL recovery. Populated internally, if sda_gpio is a valid
620 : * GPIO, for generic GPIO recovery.
621 : * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
622 : * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
623 : * for generic GPIO recovery.
624 : * @get_bus_free: Returns the bus free state as seen from the IP core in case it
625 : * has a more complex internal logic than just reading SDA. Optional.
626 : * @prepare_recovery: This will be called before starting recovery. Platform may
627 : * configure padmux here for SDA/SCL line or something else they want.
628 : * @unprepare_recovery: This will be called after completing recovery. Platform
629 : * may configure padmux here for SDA/SCL line or something else they want.
630 : * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
631 : * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
632 : * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
633 : * Optional.
634 : * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
635 : * to the I2C bus. Optional. Populated internally for GPIO recovery, if
636 : * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
637 : * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
638 : * GPIOs. Optional. Populated internally for GPIO recovery, if this state
639 : * is called "gpio" or "recovery" and pinctrl is valid.
640 : */
641 : struct i2c_bus_recovery_info {
642 : int (*recover_bus)(struct i2c_adapter *adap);
643 :
644 : int (*get_scl)(struct i2c_adapter *adap);
645 : void (*set_scl)(struct i2c_adapter *adap, int val);
646 : int (*get_sda)(struct i2c_adapter *adap);
647 : void (*set_sda)(struct i2c_adapter *adap, int val);
648 : int (*get_bus_free)(struct i2c_adapter *adap);
649 :
650 : void (*prepare_recovery)(struct i2c_adapter *adap);
651 : void (*unprepare_recovery)(struct i2c_adapter *adap);
652 :
653 : /* gpio recovery */
654 : struct gpio_desc *scl_gpiod;
655 : struct gpio_desc *sda_gpiod;
656 : struct pinctrl *pinctrl;
657 : struct pinctrl_state *pins_default;
658 : struct pinctrl_state *pins_gpio;
659 : };
660 :
661 : int i2c_recover_bus(struct i2c_adapter *adap);
662 :
663 : /* Generic recovery routines */
664 : int i2c_generic_scl_recovery(struct i2c_adapter *adap);
665 :
666 : /**
667 : * struct i2c_adapter_quirks - describe flaws of an i2c adapter
668 : * @flags: see I2C_AQ_* for possible flags and read below
669 : * @max_num_msgs: maximum number of messages per transfer
670 : * @max_write_len: maximum length of a write message
671 : * @max_read_len: maximum length of a read message
672 : * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
673 : * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
674 : *
675 : * Note about combined messages: Some I2C controllers can only send one message
676 : * per transfer, plus something called combined message or write-then-read.
677 : * This is (usually) a small write message followed by a read message and
678 : * barely enough to access register based devices like EEPROMs. There is a flag
679 : * to support this mode. It implies max_num_msg = 2 and does the length checks
680 : * with max_comb_*_len because combined message mode usually has its own
681 : * limitations. Because of HW implementations, some controllers can actually do
682 : * write-then-anything or other variants. To support that, write-then-read has
683 : * been broken out into smaller bits like write-first and read-second which can
684 : * be combined as needed.
685 : */
686 :
687 : struct i2c_adapter_quirks {
688 : u64 flags;
689 : int max_num_msgs;
690 : u16 max_write_len;
691 : u16 max_read_len;
692 : u16 max_comb_1st_msg_len;
693 : u16 max_comb_2nd_msg_len;
694 : };
695 :
696 : /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
697 : #define I2C_AQ_COMB BIT(0)
698 : /* first combined message must be write */
699 : #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
700 : /* second combined message must be read */
701 : #define I2C_AQ_COMB_READ_SECOND BIT(2)
702 : /* both combined messages must have the same target address */
703 : #define I2C_AQ_COMB_SAME_ADDR BIT(3)
704 : /* convenience macro for typical write-then read case */
705 : #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
706 : I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
707 : /* clock stretching is not supported */
708 : #define I2C_AQ_NO_CLK_STRETCH BIT(4)
709 : /* message cannot have length of 0 */
710 : #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
711 : #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
712 : #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
713 : /* adapter cannot do repeated START */
714 : #define I2C_AQ_NO_REP_START BIT(7)
715 :
716 : /*
717 : * i2c_adapter is the structure used to identify a physical i2c bus along
718 : * with the access algorithms necessary to access it.
719 : */
720 : struct i2c_adapter {
721 : struct module *owner;
722 : unsigned int class; /* classes to allow probing for */
723 : const struct i2c_algorithm *algo; /* the algorithm to access the bus */
724 : void *algo_data;
725 :
726 : /* data fields that are valid for all devices */
727 : const struct i2c_lock_operations *lock_ops;
728 : struct rt_mutex bus_lock;
729 : struct rt_mutex mux_lock;
730 :
731 : int timeout; /* in jiffies */
732 : int retries;
733 : struct device dev; /* the adapter device */
734 : unsigned long locked_flags; /* owned by the I2C core */
735 : #define I2C_ALF_IS_SUSPENDED 0
736 : #define I2C_ALF_SUSPEND_REPORTED 1
737 :
738 : int nr;
739 : char name[48];
740 : struct completion dev_released;
741 :
742 : struct mutex userspace_clients_lock;
743 : struct list_head userspace_clients;
744 :
745 : struct i2c_bus_recovery_info *bus_recovery_info;
746 : const struct i2c_adapter_quirks *quirks;
747 :
748 : struct irq_domain *host_notify_domain;
749 : struct regulator *bus_regulator;
750 : };
751 : #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
752 :
753 : static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
754 : {
755 0 : return dev_get_drvdata(&adap->dev);
756 : }
757 :
758 : static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
759 : {
760 0 : dev_set_drvdata(&adap->dev, data);
761 : }
762 :
763 : static inline struct i2c_adapter *
764 : i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
765 : {
766 : #if IS_ENABLED(CONFIG_I2C_MUX)
767 : struct device *parent = adapter->dev.parent;
768 :
769 : if (parent != NULL && parent->type == &i2c_adapter_type)
770 : return to_i2c_adapter(parent);
771 : else
772 : #endif
773 : return NULL;
774 : }
775 :
776 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
777 :
778 : /* Adapter locking functions, exported for shared pin cases */
779 : #define I2C_LOCK_ROOT_ADAPTER BIT(0)
780 : #define I2C_LOCK_SEGMENT BIT(1)
781 :
782 : /**
783 : * i2c_lock_bus - Get exclusive access to an I2C bus segment
784 : * @adapter: Target I2C bus segment
785 : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
786 : * locks only this branch in the adapter tree
787 : */
788 : static inline void
789 : i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
790 : {
791 0 : adapter->lock_ops->lock_bus(adapter, flags);
792 : }
793 :
794 : /**
795 : * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
796 : * @adapter: Target I2C bus segment
797 : * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
798 : * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
799 : *
800 : * Return: true if the I2C bus segment is locked, false otherwise
801 : */
802 : static inline int
803 : i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
804 : {
805 0 : return adapter->lock_ops->trylock_bus(adapter, flags);
806 : }
807 :
808 : /**
809 : * i2c_unlock_bus - Release exclusive access to an I2C bus segment
810 : * @adapter: Target I2C bus segment
811 : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
812 : * unlocks only this branch in the adapter tree
813 : */
814 : static inline void
815 : i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
816 : {
817 0 : adapter->lock_ops->unlock_bus(adapter, flags);
818 : }
819 :
820 : /**
821 : * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
822 : * @adap: Adapter to mark as suspended
823 : *
824 : * When using this helper to mark an adapter as suspended, the core will reject
825 : * further transfers to this adapter. The usage of this helper is optional but
826 : * recommended for devices having distinct handlers for system suspend and
827 : * runtime suspend. More complex devices are free to implement custom solutions
828 : * to reject transfers when suspended.
829 : */
830 : static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
831 : {
832 : i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
833 : set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
834 : i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
835 : }
836 :
837 : /**
838 : * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
839 : * @adap: Adapter to mark as resumed
840 : *
841 : * When using this helper to mark an adapter as resumed, the core will allow
842 : * further transfers to this adapter. See also further notes to
843 : * @i2c_mark_adapter_suspended().
844 : */
845 : static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
846 : {
847 : i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
848 : clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
849 : i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
850 : }
851 :
852 : /* i2c adapter classes (bitmask) */
853 : #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
854 : #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
855 : #define I2C_CLASS_SPD (1<<7) /* Memory modules */
856 : /* Warn users that the adapter doesn't support classes anymore */
857 : #define I2C_CLASS_DEPRECATED (1<<8)
858 :
859 : /* Internal numbers to terminate lists */
860 : #define I2C_CLIENT_END 0xfffeU
861 :
862 : /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
863 : #define I2C_ADDRS(addr, addrs...) \
864 : ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
865 :
866 :
867 : /* ----- functions exported by i2c.o */
868 :
869 : /* administration...
870 : */
871 : #if IS_ENABLED(CONFIG_I2C)
872 : int i2c_add_adapter(struct i2c_adapter *adap);
873 : int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
874 : void i2c_del_adapter(struct i2c_adapter *adap);
875 : int i2c_add_numbered_adapter(struct i2c_adapter *adap);
876 :
877 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
878 : void i2c_del_driver(struct i2c_driver *driver);
879 :
880 : /* use a define to avoid include chaining to get THIS_MODULE */
881 : #define i2c_add_driver(driver) \
882 : i2c_register_driver(THIS_MODULE, driver)
883 :
884 : static inline bool i2c_client_has_driver(struct i2c_client *client)
885 : {
886 0 : return !IS_ERR_OR_NULL(client) && client->dev.driver;
887 : }
888 :
889 : /* call the i2c_client->command() of all attached clients with
890 : * the given arguments */
891 : void i2c_clients_command(struct i2c_adapter *adap,
892 : unsigned int cmd, void *arg);
893 :
894 : struct i2c_adapter *i2c_get_adapter(int nr);
895 : void i2c_put_adapter(struct i2c_adapter *adap);
896 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
897 :
898 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
899 :
900 : /* Return the functionality mask */
901 : static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
902 : {
903 0 : return adap->algo->functionality(adap);
904 : }
905 :
906 : /* Return 1 if adapter supports everything we need, 0 if not. */
907 : static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
908 : {
909 0 : return (func & i2c_get_functionality(adap)) == func;
910 : }
911 :
912 : /**
913 : * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
914 : * @adap: i2c adapter
915 : * @quirks: quirk flags
916 : *
917 : * Return: true if the adapter has all the specified quirk flags, false if not
918 : */
919 : static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
920 : {
921 : if (!adap->quirks)
922 : return false;
923 : return (adap->quirks->flags & quirks) == quirks;
924 : }
925 :
926 : /* Return the adapter number for a specific adapter */
927 : static inline int i2c_adapter_id(struct i2c_adapter *adap)
928 : {
929 : return adap->nr;
930 : }
931 :
932 : static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
933 : {
934 0 : return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
935 : }
936 :
937 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
938 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
939 :
940 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
941 : /**
942 : * module_i2c_driver() - Helper macro for registering a modular I2C driver
943 : * @__i2c_driver: i2c_driver struct
944 : *
945 : * Helper macro for I2C drivers which do not do anything special in module
946 : * init/exit. This eliminates a lot of boilerplate. Each module may only
947 : * use this macro once, and calling it replaces module_init() and module_exit()
948 : */
949 : #define module_i2c_driver(__i2c_driver) \
950 : module_driver(__i2c_driver, i2c_add_driver, \
951 : i2c_del_driver)
952 :
953 : /**
954 : * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
955 : * @__i2c_driver: i2c_driver struct
956 : *
957 : * Helper macro for I2C drivers which do not do anything special in their
958 : * init. This eliminates a lot of boilerplate. Each driver may only
959 : * use this macro once, and calling it replaces device_initcall().
960 : */
961 : #define builtin_i2c_driver(__i2c_driver) \
962 : builtin_driver(__i2c_driver, i2c_add_driver)
963 :
964 : #endif /* I2C */
965 :
966 : #if IS_ENABLED(CONFIG_OF)
967 : /* must call put_device() when done with returned i2c_client device */
968 : struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
969 :
970 : /* must call put_device() when done with returned i2c_adapter device */
971 : struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
972 :
973 : /* must call i2c_put_adapter() when done with returned i2c_adapter device */
974 : struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
975 :
976 : const struct of_device_id
977 : *i2c_of_match_device(const struct of_device_id *matches,
978 : struct i2c_client *client);
979 :
980 : int of_i2c_get_board_info(struct device *dev, struct device_node *node,
981 : struct i2c_board_info *info);
982 :
983 : #else
984 :
985 : static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
986 : {
987 : return NULL;
988 : }
989 :
990 : static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
991 : {
992 : return NULL;
993 : }
994 :
995 : static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
996 : {
997 : return NULL;
998 : }
999 :
1000 : static inline const struct of_device_id
1001 : *i2c_of_match_device(const struct of_device_id *matches,
1002 : struct i2c_client *client)
1003 : {
1004 : return NULL;
1005 : }
1006 :
1007 : static inline int of_i2c_get_board_info(struct device *dev,
1008 : struct device_node *node,
1009 : struct i2c_board_info *info)
1010 : {
1011 : return -ENOTSUPP;
1012 : }
1013 :
1014 : #endif /* CONFIG_OF */
1015 :
1016 : struct acpi_resource;
1017 : struct acpi_resource_i2c_serialbus;
1018 :
1019 : #if IS_ENABLED(CONFIG_ACPI)
1020 : bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1021 : struct acpi_resource_i2c_serialbus **i2c);
1022 : int i2c_acpi_client_count(struct acpi_device *adev);
1023 : u32 i2c_acpi_find_bus_speed(struct device *dev);
1024 : struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
1025 : int index,
1026 : struct i2c_board_info *info);
1027 : struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
1028 : bool i2c_acpi_waive_d0_probe(struct device *dev);
1029 : #else
1030 : static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
1031 : struct acpi_resource_i2c_serialbus **i2c)
1032 : {
1033 : return false;
1034 : }
1035 : static inline int i2c_acpi_client_count(struct acpi_device *adev)
1036 : {
1037 : return 0;
1038 : }
1039 : static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1040 : {
1041 : return 0;
1042 : }
1043 : static inline struct i2c_client *i2c_acpi_new_device_by_fwnode(
1044 : struct fwnode_handle *fwnode, int index,
1045 : struct i2c_board_info *info)
1046 : {
1047 : return ERR_PTR(-ENODEV);
1048 : }
1049 : static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1050 : {
1051 : return NULL;
1052 : }
1053 : static inline bool i2c_acpi_waive_d0_probe(struct device *dev)
1054 : {
1055 : return false;
1056 : }
1057 : #endif /* CONFIG_ACPI */
1058 :
1059 : static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1060 : int index,
1061 : struct i2c_board_info *info)
1062 : {
1063 : return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info);
1064 : }
1065 :
1066 : #endif /* _LINUX_I2C_H */
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