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/rtmutex.h>
34#include <linux/irqdomain.h> /* for Host Notify IRQ */
35#include <linux/of.h> /* for struct device_node */
36#include <linux/swab.h> /* for swab16 */
37#include <uapi/linux/i2c.h>
38
39extern struct bus_type i2c_bus_type;
40extern struct device_type i2c_adapter_type;
41extern struct device_type i2c_client_type;
42
43/* --- General options ------------------------------------------------ */
44
45struct i2c_msg;
46struct i2c_algorithm;
47struct i2c_adapter;
48struct i2c_client;
49struct i2c_driver;
50struct i2c_device_identity;
51union i2c_smbus_data;
52struct i2c_board_info;
53enum i2c_slave_event;
54typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *);
55
56struct module;
57struct property_entry;
58
59#if IS_ENABLED(CONFIG_I2C)
60/*
61 * The master routines are the ones normally used to transmit data to devices
62 * on a bus (or read from them). Apart from two basic transfer functions to
63 * transmit one message at a time, a more complex version can be used to
64 * transmit an arbitrary number of messages without interruption.
65 * @count must be be less than 64k since msg.len is u16.
66 */
67extern int i2c_transfer_buffer_flags(const struct i2c_client *client,
68 char *buf, int count, u16 flags);
69
70/**
71 * i2c_master_recv - issue a single I2C message in master receive mode
72 * @client: Handle to slave device
73 * @buf: Where to store data read from slave
74 * @count: How many bytes to read, must be less than 64k since msg.len is u16
75 *
76 * Returns negative errno, or else the number of bytes read.
77 */
78static inline int i2c_master_recv(const struct i2c_client *client,
79 char *buf, int count)
80{
81 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
82};
83
84/**
85 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
86 * using a DMA safe buffer
87 * @client: Handle to slave device
88 * @buf: Where to store data read from slave, must be safe to use with DMA
89 * @count: How many bytes to read, must be less than 64k since msg.len is u16
90 *
91 * Returns negative errno, or else the number of bytes read.
92 */
93static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
94 char *buf, int count)
95{
96 return i2c_transfer_buffer_flags(client, buf, count,
97 I2C_M_RD | I2C_M_DMA_SAFE);
98};
99
100/**
101 * i2c_master_send - issue a single I2C message in master transmit mode
102 * @client: Handle to slave device
103 * @buf: Data that will be written to the slave
104 * @count: How many bytes to write, must be less than 64k since msg.len is u16
105 *
106 * Returns negative errno, or else the number of bytes written.
107 */
108static inline int i2c_master_send(const struct i2c_client *client,
109 const char *buf, int count)
110{
111 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
112};
113
114/**
115 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
116 * using a DMA safe buffer
117 * @client: Handle to slave device
118 * @buf: Data that will be written to the slave, must be safe to use with DMA
119 * @count: How many bytes to write, must be less than 64k since msg.len is u16
120 *
121 * Returns negative errno, or else the number of bytes written.
122 */
123static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
124 const char *buf, int count)
125{
126 return i2c_transfer_buffer_flags(client, (char *)buf, count,
127 I2C_M_DMA_SAFE);
128};
129
130/* Transfer num messages.
131 */
132extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
133 int num);
134/* Unlocked flavor */
135extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
136 int num);
137
138/* This is the very generalized SMBus access routine. You probably do not
139 want to use this, though; one of the functions below may be much easier,
140 and probably just as fast.
141 Note that we use i2c_adapter here, because you do not need a specific
142 smbus adapter to call this function. */
143s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
144 unsigned short flags, char read_write, u8 command,
145 int protocol, union i2c_smbus_data *data);
146
147/* Unlocked flavor */
148s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
149 unsigned short flags, char read_write, u8 command,
150 int protocol, union i2c_smbus_data *data);
151
152/* Now follow the 'nice' access routines. These also document the calling
153 conventions of i2c_smbus_xfer. */
154
155extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
156extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
157extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
158 u8 command);
159extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
160 u8 command, u8 value);
161extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
162 u8 command);
163extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
164 u8 command, u16 value);
165
166static inline s32
167i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
168{
169 s32 value = i2c_smbus_read_word_data(client, command);
170
171 return (value < 0) ? value : swab16(value);
172}
173
174static inline s32
175i2c_smbus_write_word_swapped(const struct i2c_client *client,
176 u8 command, u16 value)
177{
178 return i2c_smbus_write_word_data(client, command, swab16(value));
179}
180
181/* Returns the number of read bytes */
182extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
183 u8 command, u8 *values);
184extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
185 u8 command, u8 length, const u8 *values);
186/* Returns the number of read bytes */
187extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
188 u8 command, u8 length, u8 *values);
189extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
190 u8 command, u8 length,
191 const u8 *values);
192extern s32
193i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
194 u8 command, u8 length, u8 *values);
195int i2c_get_device_id(const struct i2c_client *client,
196 struct i2c_device_identity *id);
197#endif /* I2C */
198
199/**
200 * struct i2c_device_identity - i2c client device identification
201 * @manufacturer_id: 0 - 4095, database maintained by NXP
202 * @part_id: 0 - 511, according to manufacturer
203 * @die_revision: 0 - 7, according to manufacturer
204 */
205struct i2c_device_identity {
206 u16 manufacturer_id;
207#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
208#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
209#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
210#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
211#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
212#define I2C_DEVICE_ID_ANALOG_DEVICES 5
213#define I2C_DEVICE_ID_STMICROELECTRONICS 6
214#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
215#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
216#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
217#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
218#define I2C_DEVICE_ID_FLIR 11
219#define I2C_DEVICE_ID_O2MICRO 12
220#define I2C_DEVICE_ID_ATMEL 13
221#define I2C_DEVICE_ID_NONE 0xffff
222 u16 part_id;
223 u8 die_revision;
224};
225
226enum i2c_alert_protocol {
227 I2C_PROTOCOL_SMBUS_ALERT,
228 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
229};
230
231/**
232 * struct i2c_driver - represent an I2C device driver
233 * @class: What kind of i2c device we instantiate (for detect)
234 * @probe: Callback for device binding - soon to be deprecated
235 * @probe_new: New callback for device binding
236 * @remove: Callback for device unbinding
237 * @shutdown: Callback for device shutdown
238 * @alert: Alert callback, for example for the SMBus alert protocol
239 * @command: Callback for bus-wide signaling (optional)
240 * @driver: Device driver model driver
241 * @id_table: List of I2C devices supported by this driver
242 * @detect: Callback for device detection
243 * @address_list: The I2C addresses to probe (for detect)
244 * @clients: List of detected clients we created (for i2c-core use only)
245 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
246 *
247 * The driver.owner field should be set to the module owner of this driver.
248 * The driver.name field should be set to the name of this driver.
249 *
250 * For automatic device detection, both @detect and @address_list must
251 * be defined. @class should also be set, otherwise only devices forced
252 * with module parameters will be created. The detect function must
253 * fill at least the name field of the i2c_board_info structure it is
254 * handed upon successful detection, and possibly also the flags field.
255 *
256 * If @detect is missing, the driver will still work fine for enumerated
257 * devices. Detected devices simply won't be supported. This is expected
258 * for the many I2C/SMBus devices which can't be detected reliably, and
259 * the ones which can always be enumerated in practice.
260 *
261 * The i2c_client structure which is handed to the @detect callback is
262 * not a real i2c_client. It is initialized just enough so that you can
263 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
264 * else with it. In particular, calling dev_dbg and friends on it is
265 * not allowed.
266 */
267struct i2c_driver {
268 unsigned int class;
269
270 /* Standard driver model interfaces */
271 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
272 int (*remove)(struct i2c_client *);
273
274 /* New driver model interface to aid the seamless removal of the
275 * current probe()'s, more commonly unused than used second parameter.
276 */
277 int (*probe_new)(struct i2c_client *);
278
279 /* driver model interfaces that don't relate to enumeration */
280 void (*shutdown)(struct i2c_client *);
281
282 /* Alert callback, for example for the SMBus alert protocol.
283 * The format and meaning of the data value depends on the protocol.
284 * For the SMBus alert protocol, there is a single bit of data passed
285 * as the alert response's low bit ("event flag").
286 * For the SMBus Host Notify protocol, the data corresponds to the
287 * 16-bit payload data reported by the slave device acting as master.
288 */
289 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
290 unsigned int data);
291
292 /* a ioctl like command that can be used to perform specific functions
293 * with the device.
294 */
295 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
296
297 struct device_driver driver;
298 const struct i2c_device_id *id_table;
299
300 /* Device detection callback for automatic device creation */
301 int (*detect)(struct i2c_client *, struct i2c_board_info *);
302 const unsigned short *address_list;
303 struct list_head clients;
304
305 bool disable_i2c_core_irq_mapping;
306};
307#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
308
309/**
310 * struct i2c_client - represent an I2C slave device
311 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
312 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
313 * @addr: Address used on the I2C bus connected to the parent adapter.
314 * @name: Indicates the type of the device, usually a chip name that's
315 * generic enough to hide second-sourcing and compatible revisions.
316 * @adapter: manages the bus segment hosting this I2C device
317 * @dev: Driver model device node for the slave.
318 * @irq: indicates the IRQ generated by this device (if any)
319 * @detected: member of an i2c_driver.clients list or i2c-core's
320 * userspace_devices list
321 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
322 * calls it to pass on slave events to the slave driver.
323 *
324 * An i2c_client identifies a single device (i.e. chip) connected to an
325 * i2c bus. The behaviour exposed to Linux is defined by the driver
326 * managing the device.
327 */
328struct i2c_client {
329 unsigned short flags; /* div., see below */
330 unsigned short addr; /* chip address - NOTE: 7bit */
331 /* addresses are stored in the */
332 /* _LOWER_ 7 bits */
333 char name[I2C_NAME_SIZE];
334 struct i2c_adapter *adapter; /* the adapter we sit on */
335 struct device dev; /* the device structure */
336 int init_irq; /* irq set at initialization */
337 int irq; /* irq issued by device */
338 struct list_head detected;
339#if IS_ENABLED(CONFIG_I2C_SLAVE)
340 i2c_slave_cb_t slave_cb; /* callback for slave mode */
341#endif
342};
343#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
344
345extern struct i2c_client *i2c_verify_client(struct device *dev);
346extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
347extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
348 const struct i2c_client *client);
349
350static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
351{
352 struct device * const dev = container_of(kobj, struct device, kobj);
353 return to_i2c_client(dev);
354}
355
356static inline void *i2c_get_clientdata(const struct i2c_client *dev)
357{
358 return dev_get_drvdata(&dev->dev);
359}
360
361static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
362{
363 dev_set_drvdata(&dev->dev, data);
364}
365
366/* I2C slave support */
367
368#if IS_ENABLED(CONFIG_I2C_SLAVE)
369enum i2c_slave_event {
370 I2C_SLAVE_READ_REQUESTED,
371 I2C_SLAVE_WRITE_REQUESTED,
372 I2C_SLAVE_READ_PROCESSED,
373 I2C_SLAVE_WRITE_RECEIVED,
374 I2C_SLAVE_STOP,
375};
376
377extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
378extern int i2c_slave_unregister(struct i2c_client *client);
379extern bool i2c_detect_slave_mode(struct device *dev);
380
381static inline int i2c_slave_event(struct i2c_client *client,
382 enum i2c_slave_event event, u8 *val)
383{
384 return client->slave_cb(client, event, val);
385}
386#else
387static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
388#endif
389
390/**
391 * struct i2c_board_info - template for device creation
392 * @type: chip type, to initialize i2c_client.name
393 * @flags: to initialize i2c_client.flags
394 * @addr: stored in i2c_client.addr
395 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
396 * @platform_data: stored in i2c_client.dev.platform_data
397 * @of_node: pointer to OpenFirmware device node
398 * @fwnode: device node supplied by the platform firmware
399 * @properties: additional device properties for the device
400 * @resources: resources associated with the device
401 * @num_resources: number of resources in the @resources array
402 * @irq: stored in i2c_client.irq
403 *
404 * I2C doesn't actually support hardware probing, although controllers and
405 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
406 * a device at a given address. Drivers commonly need more information than
407 * that, such as chip type, configuration, associated IRQ, and so on.
408 *
409 * i2c_board_info is used to build tables of information listing I2C devices
410 * that are present. This information is used to grow the driver model tree.
411 * For mainboards this is done statically using i2c_register_board_info();
412 * bus numbers identify adapters that aren't yet available. For add-on boards,
413 * i2c_new_device() does this dynamically with the adapter already known.
414 */
415struct i2c_board_info {
416 char type[I2C_NAME_SIZE];
417 unsigned short flags;
418 unsigned short addr;
419 const char *dev_name;
420 void *platform_data;
421 struct device_node *of_node;
422 struct fwnode_handle *fwnode;
423 const struct property_entry *properties;
424 const struct resource *resources;
425 unsigned int num_resources;
426 int irq;
427};
428
429/**
430 * I2C_BOARD_INFO - macro used to list an i2c device and its address
431 * @dev_type: identifies the device type
432 * @dev_addr: the device's address on the bus.
433 *
434 * This macro initializes essential fields of a struct i2c_board_info,
435 * declaring what has been provided on a particular board. Optional
436 * fields (such as associated irq, or device-specific platform_data)
437 * are provided using conventional syntax.
438 */
439#define I2C_BOARD_INFO(dev_type, dev_addr) \
440 .type = dev_type, .addr = (dev_addr)
441
442
443#if IS_ENABLED(CONFIG_I2C)
444/* Add-on boards should register/unregister their devices; e.g. a board
445 * with integrated I2C, a config eeprom, sensors, and a codec that's
446 * used in conjunction with the primary hardware.
447 */
448extern struct i2c_client *
449i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
450
451/* If you don't know the exact address of an I2C device, use this variant
452 * instead, which can probe for device presence in a list of possible
453 * addresses. The "probe" callback function is optional. If it is provided,
454 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
455 * a default probing method is used.
456 */
457extern struct i2c_client *
458i2c_new_probed_device(struct i2c_adapter *adap,
459 struct i2c_board_info *info,
460 unsigned short const *addr_list,
461 int (*probe)(struct i2c_adapter *, unsigned short addr));
462
463/* Common custom probe functions */
464extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
465
466/* For devices that use several addresses, use i2c_new_dummy() to make
467 * client handles for the extra addresses.
468 */
469extern struct i2c_client *
470i2c_new_dummy(struct i2c_adapter *adap, u16 address);
471
472extern struct i2c_client *
473i2c_new_secondary_device(struct i2c_client *client,
474 const char *name,
475 u16 default_addr);
476
477extern void i2c_unregister_device(struct i2c_client *);
478#endif /* I2C */
479
480/* Mainboard arch_initcall() code should register all its I2C devices.
481 * This is done at arch_initcall time, before declaring any i2c adapters.
482 * Modules for add-on boards must use other calls.
483 */
484#ifdef CONFIG_I2C_BOARDINFO
485extern int
486i2c_register_board_info(int busnum, struct i2c_board_info const *info,
487 unsigned n);
488#else
489static inline int
490i2c_register_board_info(int busnum, struct i2c_board_info const *info,
491 unsigned n)
492{
493 return 0;
494}
495#endif /* I2C_BOARDINFO */
496
497/**
498 * struct i2c_algorithm - represent I2C transfer method
499 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
500 * defined by the msgs array, with num messages available to transfer via
501 * the adapter specified by adap.
502 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
503 * is not present, then the bus layer will try and convert the SMBus calls
504 * into I2C transfers instead.
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 field should indicate the type of
516 * error code that occurred during the transfer, as documented in the kernel
517 * Documentation file Documentation/i2c/fault-codes.
518 */
519struct i2c_algorithm {
520 /* If an adapter algorithm can't do I2C-level access, set master_xfer
521 to NULL. If an adapter algorithm can do SMBus access, set
522 smbus_xfer. If set to NULL, the SMBus protocol is simulated
523 using common I2C messages */
524 /* master_xfer should return the number of messages successfully
525 processed, or a negative value on error */
526 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
527 int num);
528 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
529 unsigned short flags, char read_write,
530 u8 command, int size, union i2c_smbus_data *data);
531
532 /* To determine what the adapter supports */
533 u32 (*functionality) (struct i2c_adapter *);
534
535#if IS_ENABLED(CONFIG_I2C_SLAVE)
536 int (*reg_slave)(struct i2c_client *client);
537 int (*unreg_slave)(struct i2c_client *client);
538#endif
539};
540
541/**
542 * struct i2c_lock_operations - represent I2C locking operations
543 * @lock_bus: Get exclusive access to an I2C bus segment
544 * @trylock_bus: Try to get exclusive access to an I2C bus segment
545 * @unlock_bus: Release exclusive access to an I2C bus segment
546 *
547 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
548 */
549struct i2c_lock_operations {
550 void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
551 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
552 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
553};
554
555/**
556 * struct i2c_timings - I2C timing information
557 * @bus_freq_hz: the bus frequency in Hz
558 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
559 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
560 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
561 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
562 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
563 */
564struct i2c_timings {
565 u32 bus_freq_hz;
566 u32 scl_rise_ns;
567 u32 scl_fall_ns;
568 u32 scl_int_delay_ns;
569 u32 sda_fall_ns;
570 u32 sda_hold_ns;
571};
572
573/**
574 * struct i2c_bus_recovery_info - I2C bus recovery information
575 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
576 * i2c_generic_scl_recovery().
577 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
578 * recovery. Populated internally for generic GPIO recovery.
579 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
580 * Populated internally for generic GPIO recovery.
581 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
582 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
583 * GPIO, for generic GPIO recovery.
584 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
585 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
586 * for generic GPIO recovery.
587 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
588 * has a more complex internal logic than just reading SDA. Optional.
589 * @prepare_recovery: This will be called before starting recovery. Platform may
590 * configure padmux here for SDA/SCL line or something else they want.
591 * @unprepare_recovery: This will be called after completing recovery. Platform
592 * may configure padmux here for SDA/SCL line or something else they want.
593 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
594 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
595 */
596struct i2c_bus_recovery_info {
597 int (*recover_bus)(struct i2c_adapter *adap);
598
599 int (*get_scl)(struct i2c_adapter *adap);
600 void (*set_scl)(struct i2c_adapter *adap, int val);
601 int (*get_sda)(struct i2c_adapter *adap);
602 void (*set_sda)(struct i2c_adapter *adap, int val);
603 int (*get_bus_free)(struct i2c_adapter *adap);
604
605 void (*prepare_recovery)(struct i2c_adapter *adap);
606 void (*unprepare_recovery)(struct i2c_adapter *adap);
607
608 /* gpio recovery */
609 struct gpio_desc *scl_gpiod;
610 struct gpio_desc *sda_gpiod;
611};
612
613int i2c_recover_bus(struct i2c_adapter *adap);
614
615/* Generic recovery routines */
616int i2c_generic_scl_recovery(struct i2c_adapter *adap);
617
618/**
619 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
620 * @flags: see I2C_AQ_* for possible flags and read below
621 * @max_num_msgs: maximum number of messages per transfer
622 * @max_write_len: maximum length of a write message
623 * @max_read_len: maximum length of a read message
624 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
625 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
626 *
627 * Note about combined messages: Some I2C controllers can only send one message
628 * per transfer, plus something called combined message or write-then-read.
629 * This is (usually) a small write message followed by a read message and
630 * barely enough to access register based devices like EEPROMs. There is a flag
631 * to support this mode. It implies max_num_msg = 2 and does the length checks
632 * with max_comb_*_len because combined message mode usually has its own
633 * limitations. Because of HW implementations, some controllers can actually do
634 * write-then-anything or other variants. To support that, write-then-read has
635 * been broken out into smaller bits like write-first and read-second which can
636 * be combined as needed.
637 */
638
639struct i2c_adapter_quirks {
640 u64 flags;
641 int max_num_msgs;
642 u16 max_write_len;
643 u16 max_read_len;
644 u16 max_comb_1st_msg_len;
645 u16 max_comb_2nd_msg_len;
646};
647
648/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
649#define I2C_AQ_COMB BIT(0)
650/* first combined message must be write */
651#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
652/* second combined message must be read */
653#define I2C_AQ_COMB_READ_SECOND BIT(2)
654/* both combined messages must have the same target address */
655#define I2C_AQ_COMB_SAME_ADDR BIT(3)
656/* convenience macro for typical write-then read case */
657#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
658 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
659/* clock stretching is not supported */
660#define I2C_AQ_NO_CLK_STRETCH BIT(4)
661/* message cannot have length of 0 */
662#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
663#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
664#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
665
666/*
667 * i2c_adapter is the structure used to identify a physical i2c bus along
668 * with the access algorithms necessary to access it.
669 */
670struct i2c_adapter {
671 struct module *owner;
672 unsigned int class; /* classes to allow probing for */
673 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
674 void *algo_data;
675
676 /* data fields that are valid for all devices */
677 const struct i2c_lock_operations *lock_ops;
678 struct rt_mutex bus_lock;
679 struct rt_mutex mux_lock;
680
681 int timeout; /* in jiffies */
682 int retries;
683 struct device dev; /* the adapter device */
684 unsigned long locked_flags; /* owned by the I2C core */
685#define I2C_ALF_IS_SUSPENDED 0
686
687 int nr;
688 char name[48];
689 struct completion dev_released;
690
691 struct mutex userspace_clients_lock;
692 struct list_head userspace_clients;
693
694 struct i2c_bus_recovery_info *bus_recovery_info;
695 const struct i2c_adapter_quirks *quirks;
696
697 struct irq_domain *host_notify_domain;
698};
699#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
700
701static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
702{
703 return dev_get_drvdata(&dev->dev);
704}
705
706static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
707{
708 dev_set_drvdata(&dev->dev, data);
709}
710
711static inline struct i2c_adapter *
712i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
713{
714#if IS_ENABLED(CONFIG_I2C_MUX)
715 struct device *parent = adapter->dev.parent;
716
717 if (parent != NULL && parent->type == &i2c_adapter_type)
718 return to_i2c_adapter(parent);
719 else
720#endif
721 return NULL;
722}
723
724int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
725
726/* Adapter locking functions, exported for shared pin cases */
727#define I2C_LOCK_ROOT_ADAPTER BIT(0)
728#define I2C_LOCK_SEGMENT BIT(1)
729
730/**
731 * i2c_lock_bus - Get exclusive access to an I2C bus segment
732 * @adapter: Target I2C bus segment
733 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
734 * locks only this branch in the adapter tree
735 */
736static inline void
737i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
738{
739 adapter->lock_ops->lock_bus(adapter, flags);
740}
741
742/**
743 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
744 * @adapter: Target I2C bus segment
745 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
746 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
747 *
748 * Return: true if the I2C bus segment is locked, false otherwise
749 */
750static inline int
751i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
752{
753 return adapter->lock_ops->trylock_bus(adapter, flags);
754}
755
756/**
757 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
758 * @adapter: Target I2C bus segment
759 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
760 * unlocks only this branch in the adapter tree
761 */
762static inline void
763i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
764{
765 adapter->lock_ops->unlock_bus(adapter, flags);
766}
767
768/**
769 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
770 * @adap: Adapter to mark as suspended
771 *
772 * When using this helper to mark an adapter as suspended, the core will reject
773 * further transfers to this adapter. The usage of this helper is optional but
774 * recommended for devices having distinct handlers for system suspend and
775 * runtime suspend. More complex devices are free to implement custom solutions
776 * to reject transfers when suspended.
777 */
778static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
779{
780 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
781 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
782 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
783}
784
785/**
786 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
787 * @adap: Adapter to mark as resumed
788 *
789 * When using this helper to mark an adapter as resumed, the core will allow
790 * further transfers to this adapter. See also further notes to
791 * @i2c_mark_adapter_suspended().
792 */
793static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
794{
795 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
796 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
797 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
798}
799
800/*flags for the client struct: */
801#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
802#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
803 /* Must equal I2C_M_TEN below */
804#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
805#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
806#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
807#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
808 /* Must match I2C_M_STOP|IGNORE_NAK */
809
810/* i2c adapter classes (bitmask) */
811#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
812#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
813#define I2C_CLASS_SPD (1<<7) /* Memory modules */
814/* Warn users that the adapter doesn't support classes anymore */
815#define I2C_CLASS_DEPRECATED (1<<8)
816
817/* Internal numbers to terminate lists */
818#define I2C_CLIENT_END 0xfffeU
819
820/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
821#define I2C_ADDRS(addr, addrs...) \
822 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
823
824
825/* ----- functions exported by i2c.o */
826
827/* administration...
828 */
829#if IS_ENABLED(CONFIG_I2C)
830extern int i2c_add_adapter(struct i2c_adapter *);
831extern void i2c_del_adapter(struct i2c_adapter *);
832extern int i2c_add_numbered_adapter(struct i2c_adapter *);
833
834extern int i2c_register_driver(struct module *, struct i2c_driver *);
835extern void i2c_del_driver(struct i2c_driver *);
836
837/* use a define to avoid include chaining to get THIS_MODULE */
838#define i2c_add_driver(driver) \
839 i2c_register_driver(THIS_MODULE, driver)
840
841extern struct i2c_client *i2c_use_client(struct i2c_client *client);
842extern void i2c_release_client(struct i2c_client *client);
843
844/* call the i2c_client->command() of all attached clients with
845 * the given arguments */
846extern void i2c_clients_command(struct i2c_adapter *adap,
847 unsigned int cmd, void *arg);
848
849extern struct i2c_adapter *i2c_get_adapter(int nr);
850extern void i2c_put_adapter(struct i2c_adapter *adap);
851extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
852
853void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
854
855/* Return the functionality mask */
856static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
857{
858 return adap->algo->functionality(adap);
859}
860
861/* Return 1 if adapter supports everything we need, 0 if not. */
862static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
863{
864 return (func & i2c_get_functionality(adap)) == func;
865}
866
867/**
868 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
869 * @adap: i2c adapter
870 * @quirks: quirk flags
871 *
872 * Return: true if the adapter has all the specified quirk flags, false if not
873 */
874static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
875{
876 if (!adap->quirks)
877 return false;
878 return (adap->quirks->flags & quirks) == quirks;
879}
880
881/* Return the adapter number for a specific adapter */
882static inline int i2c_adapter_id(struct i2c_adapter *adap)
883{
884 return adap->nr;
885}
886
887static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
888{
889 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
890}
891
892u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
893void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
894
895int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
896/**
897 * module_i2c_driver() - Helper macro for registering a modular I2C driver
898 * @__i2c_driver: i2c_driver struct
899 *
900 * Helper macro for I2C drivers which do not do anything special in module
901 * init/exit. This eliminates a lot of boilerplate. Each module may only
902 * use this macro once, and calling it replaces module_init() and module_exit()
903 */
904#define module_i2c_driver(__i2c_driver) \
905 module_driver(__i2c_driver, i2c_add_driver, \
906 i2c_del_driver)
907
908/**
909 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
910 * @__i2c_driver: i2c_driver struct
911 *
912 * Helper macro for I2C drivers which do not do anything special in their
913 * init. This eliminates a lot of boilerplate. Each driver may only
914 * use this macro once, and calling it replaces device_initcall().
915 */
916#define builtin_i2c_driver(__i2c_driver) \
917 builtin_driver(__i2c_driver, i2c_add_driver)
918
919#endif /* I2C */
920
921#if IS_ENABLED(CONFIG_OF)
922/* must call put_device() when done with returned i2c_client device */
923extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
924
925/* must call put_device() when done with returned i2c_adapter device */
926extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
927
928/* must call i2c_put_adapter() when done with returned i2c_adapter device */
929struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
930
931extern const struct of_device_id
932*i2c_of_match_device(const struct of_device_id *matches,
933 struct i2c_client *client);
934
935int of_i2c_get_board_info(struct device *dev, struct device_node *node,
936 struct i2c_board_info *info);
937
938#else
939
940static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
941{
942 return NULL;
943}
944
945static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
946{
947 return NULL;
948}
949
950static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
951{
952 return NULL;
953}
954
955static inline const struct of_device_id
956*i2c_of_match_device(const struct of_device_id *matches,
957 struct i2c_client *client)
958{
959 return NULL;
960}
961
962static inline int of_i2c_get_board_info(struct device *dev,
963 struct device_node *node,
964 struct i2c_board_info *info)
965{
966 return -ENOTSUPP;
967}
968
969#endif /* CONFIG_OF */
970
971struct acpi_resource;
972struct acpi_resource_i2c_serialbus;
973
974#if IS_ENABLED(CONFIG_ACPI)
975bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
976 struct acpi_resource_i2c_serialbus **i2c);
977u32 i2c_acpi_find_bus_speed(struct device *dev);
978struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
979 struct i2c_board_info *info);
980#else
981static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
982 struct acpi_resource_i2c_serialbus **i2c)
983{
984 return false;
985}
986static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
987{
988 return 0;
989}
990static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
991 int index, struct i2c_board_info *info)
992{
993 return NULL;
994}
995#endif /* CONFIG_ACPI */
996
997#endif /* _LINUX_I2C_H */
998