1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* ------------------------------------------------------------------------- */
4 /* i2c.h - definitions for the i2c-bus interface */
6 /* ------------------------------------------------------------------------- */
7 /* Copyright (C) 1995-2000 Simon G. Vogl
10 /* ------------------------------------------------------------------------- */
12 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
13 Frodo Looijaard <frodol@dds.nl> */
17 #include <linux/mod_devicetable.h>
18 #include <linux/device.h> /* for struct device */
19 #include <linux/sched.h> /* for completion */
20 #include <linux/mutex.h>
21 #include <linux/rtmutex.h>
22 #include <linux/irqdomain.h> /* for Host Notify IRQ */
23 #include <linux/of.h> /* for struct device_node */
24 #include <linux/swab.h> /* for swab16 */
25 #include <uapi/linux/i2c.h>
27 extern struct bus_type i2c_bus_type
;
28 extern struct device_type i2c_adapter_type
;
29 extern struct device_type i2c_client_type
;
31 /* --- General options ------------------------------------------------ */
38 struct i2c_device_identity
;
40 struct i2c_board_info
;
42 typedef int (*i2c_slave_cb_t
)(struct i2c_client
*, enum i2c_slave_event
, u8
*);
45 struct property_entry
;
47 #if IS_ENABLED(CONFIG_I2C)
49 * The master routines are the ones normally used to transmit data to devices
50 * on a bus (or read from them). Apart from two basic transfer functions to
51 * transmit one message at a time, a more complex version can be used to
52 * transmit an arbitrary number of messages without interruption.
53 * @count must be be less than 64k since msg.len is u16.
55 extern int i2c_transfer_buffer_flags(const struct i2c_client
*client
,
56 char *buf
, int count
, u16 flags
);
59 * i2c_master_recv - issue a single I2C message in master receive mode
60 * @client: Handle to slave device
61 * @buf: Where to store data read from slave
62 * @count: How many bytes to read, must be less than 64k since msg.len is u16
64 * Returns negative errno, or else the number of bytes read.
66 static inline int i2c_master_recv(const struct i2c_client
*client
,
69 return i2c_transfer_buffer_flags(client
, buf
, count
, I2C_M_RD
);
73 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
74 * using a DMA safe buffer
75 * @client: Handle to slave device
76 * @buf: Where to store data read from slave, must be safe to use with DMA
77 * @count: How many bytes to read, must be less than 64k since msg.len is u16
79 * Returns negative errno, or else the number of bytes read.
81 static inline int i2c_master_recv_dmasafe(const struct i2c_client
*client
,
84 return i2c_transfer_buffer_flags(client
, buf
, count
,
85 I2C_M_RD
| I2C_M_DMA_SAFE
);
89 * i2c_master_send - issue a single I2C message in master transmit mode
90 * @client: Handle to slave device
91 * @buf: Data that will be written to the slave
92 * @count: How many bytes to write, must be less than 64k since msg.len is u16
94 * Returns negative errno, or else the number of bytes written.
96 static inline int i2c_master_send(const struct i2c_client
*client
,
97 const char *buf
, int count
)
99 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
, 0);
103 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
104 * using a DMA safe buffer
105 * @client: Handle to slave device
106 * @buf: Data that will be written to the slave, must be safe to use with DMA
107 * @count: How many bytes to write, must be less than 64k since msg.len is u16
109 * Returns negative errno, or else the number of bytes written.
111 static inline int i2c_master_send_dmasafe(const struct i2c_client
*client
,
112 const char *buf
, int count
)
114 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
,
118 /* Transfer num messages.
120 extern int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
122 /* Unlocked flavor */
123 extern int __i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
126 /* This is the very generalized SMBus access routine. You probably do not
127 want to use this, though; one of the functions below may be much easier,
128 and probably just as fast.
129 Note that we use i2c_adapter here, because you do not need a specific
130 smbus adapter to call this function. */
131 s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
132 unsigned short flags
, char read_write
, u8 command
,
133 int protocol
, union i2c_smbus_data
*data
);
135 /* Unlocked flavor */
136 s32
__i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
137 unsigned short flags
, char read_write
, u8 command
,
138 int protocol
, union i2c_smbus_data
*data
);
140 /* Now follow the 'nice' access routines. These also document the calling
141 conventions of i2c_smbus_xfer. */
143 extern s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
144 extern s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
145 extern s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
,
147 extern s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
148 u8 command
, u8 value
);
149 extern s32
i2c_smbus_read_word_data(const struct i2c_client
*client
,
151 extern s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
152 u8 command
, u16 value
);
155 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
157 s32 value
= i2c_smbus_read_word_data(client
, command
);
159 return (value
< 0) ? value
: swab16(value
);
163 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
164 u8 command
, u16 value
)
166 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
169 /* Returns the number of read bytes */
170 extern s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
171 u8 command
, u8
*values
);
172 extern s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
173 u8 command
, u8 length
, const u8
*values
);
174 /* Returns the number of read bytes */
175 extern s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
176 u8 command
, u8 length
, u8
*values
);
177 extern s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
178 u8 command
, u8 length
,
181 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client
*client
,
182 u8 command
, u8 length
, u8
*values
);
183 int i2c_get_device_id(const struct i2c_client
*client
,
184 struct i2c_device_identity
*id
);
188 * struct i2c_device_identity - i2c client device identification
189 * @manufacturer_id: 0 - 4095, database maintained by NXP
190 * @part_id: 0 - 511, according to manufacturer
191 * @die_revision: 0 - 7, according to manufacturer
193 struct i2c_device_identity
{
195 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
197 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
198 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
199 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
200 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
201 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
202 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
203 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
204 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
205 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
206 #define I2C_DEVICE_ID_FLIR 11
207 #define I2C_DEVICE_ID_O2MICRO 12
208 #define I2C_DEVICE_ID_ATMEL 13
209 #define I2C_DEVICE_ID_NONE 0xffff
214 enum i2c_alert_protocol
{
215 I2C_PROTOCOL_SMBUS_ALERT
,
216 I2C_PROTOCOL_SMBUS_HOST_NOTIFY
,
220 * struct i2c_driver - represent an I2C device driver
221 * @class: What kind of i2c device we instantiate (for detect)
222 * @probe: Callback for device binding - soon to be deprecated
223 * @probe_new: New callback for device binding
224 * @remove: Callback for device unbinding
225 * @shutdown: Callback for device shutdown
226 * @alert: Alert callback, for example for the SMBus alert protocol
227 * @command: Callback for bus-wide signaling (optional)
228 * @driver: Device driver model driver
229 * @id_table: List of I2C devices supported by this driver
230 * @detect: Callback for device detection
231 * @address_list: The I2C addresses to probe (for detect)
232 * @clients: List of detected clients we created (for i2c-core use only)
233 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
235 * The driver.owner field should be set to the module owner of this driver.
236 * The driver.name field should be set to the name of this driver.
238 * For automatic device detection, both @detect and @address_list must
239 * be defined. @class should also be set, otherwise only devices forced
240 * with module parameters will be created. The detect function must
241 * fill at least the name field of the i2c_board_info structure it is
242 * handed upon successful detection, and possibly also the flags field.
244 * If @detect is missing, the driver will still work fine for enumerated
245 * devices. Detected devices simply won't be supported. This is expected
246 * for the many I2C/SMBus devices which can't be detected reliably, and
247 * the ones which can always be enumerated in practice.
249 * The i2c_client structure which is handed to the @detect callback is
250 * not a real i2c_client. It is initialized just enough so that you can
251 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
252 * else with it. In particular, calling dev_dbg and friends on it is
258 /* Standard driver model interfaces */
259 int (*probe
)(struct i2c_client
*, const struct i2c_device_id
*);
260 int (*remove
)(struct i2c_client
*);
262 /* New driver model interface to aid the seamless removal of the
263 * current probe()'s, more commonly unused than used second parameter.
265 int (*probe_new
)(struct i2c_client
*);
267 /* driver model interfaces that don't relate to enumeration */
268 void (*shutdown
)(struct i2c_client
*);
270 /* Alert callback, for example for the SMBus alert protocol.
271 * The format and meaning of the data value depends on the protocol.
272 * For the SMBus alert protocol, there is a single bit of data passed
273 * as the alert response's low bit ("event flag").
274 * For the SMBus Host Notify protocol, the data corresponds to the
275 * 16-bit payload data reported by the slave device acting as master.
277 void (*alert
)(struct i2c_client
*, enum i2c_alert_protocol protocol
,
280 /* a ioctl like command that can be used to perform specific functions
283 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
285 struct device_driver driver
;
286 const struct i2c_device_id
*id_table
;
288 /* Device detection callback for automatic device creation */
289 int (*detect
)(struct i2c_client
*, struct i2c_board_info
*);
290 const unsigned short *address_list
;
291 struct list_head clients
;
293 bool disable_i2c_core_irq_mapping
;
295 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
298 * struct i2c_client - represent an I2C slave device
299 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
300 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
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 * @irq: indicates the IRQ generated by this device (if any)
307 * @detected: member of an i2c_driver.clients list or i2c-core's
308 * userspace_devices list
309 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
310 * calls it to pass on slave events to the slave driver.
312 * An i2c_client identifies a single device (i.e. chip) connected to an
313 * i2c bus. The behaviour exposed to Linux is defined by the driver
314 * managing the device.
317 unsigned short flags
; /* div., see below */
318 unsigned short addr
; /* chip address - NOTE: 7bit */
319 /* addresses are stored in the */
321 char name
[I2C_NAME_SIZE
];
322 struct i2c_adapter
*adapter
; /* the adapter we sit on */
323 struct device dev
; /* the device structure */
324 int init_irq
; /* irq set at initialization */
325 int irq
; /* irq issued by device */
326 struct list_head detected
;
327 #if IS_ENABLED(CONFIG_I2C_SLAVE)
328 i2c_slave_cb_t slave_cb
; /* callback for slave mode */
331 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
333 extern struct i2c_client
*i2c_verify_client(struct device
*dev
);
334 extern struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
335 extern const struct i2c_device_id
*i2c_match_id(const struct i2c_device_id
*id
,
336 const struct i2c_client
*client
);
338 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
340 struct device
* const dev
= container_of(kobj
, struct device
, kobj
);
341 return to_i2c_client(dev
);
344 static inline void *i2c_get_clientdata(const struct i2c_client
*dev
)
346 return dev_get_drvdata(&dev
->dev
);
349 static inline void i2c_set_clientdata(struct i2c_client
*dev
, void *data
)
351 dev_set_drvdata(&dev
->dev
, data
);
354 /* I2C slave support */
356 #if IS_ENABLED(CONFIG_I2C_SLAVE)
357 enum i2c_slave_event
{
358 I2C_SLAVE_READ_REQUESTED
,
359 I2C_SLAVE_WRITE_REQUESTED
,
360 I2C_SLAVE_READ_PROCESSED
,
361 I2C_SLAVE_WRITE_RECEIVED
,
365 extern int i2c_slave_register(struct i2c_client
*client
, i2c_slave_cb_t slave_cb
);
366 extern int i2c_slave_unregister(struct i2c_client
*client
);
367 extern bool i2c_detect_slave_mode(struct device
*dev
);
369 static inline int i2c_slave_event(struct i2c_client
*client
,
370 enum i2c_slave_event event
, u8
*val
)
372 return client
->slave_cb(client
, event
, val
);
375 static inline bool i2c_detect_slave_mode(struct device
*dev
) { return false; }
379 * struct i2c_board_info - template for device creation
380 * @type: chip type, to initialize i2c_client.name
381 * @flags: to initialize i2c_client.flags
382 * @addr: stored in i2c_client.addr
383 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
384 * @platform_data: stored in i2c_client.dev.platform_data
385 * @of_node: pointer to OpenFirmware device node
386 * @fwnode: device node supplied by the platform firmware
387 * @properties: additional device properties for the device
388 * @resources: resources associated with the device
389 * @num_resources: number of resources in the @resources array
390 * @irq: stored in i2c_client.irq
392 * I2C doesn't actually support hardware probing, although controllers and
393 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
394 * a device at a given address. Drivers commonly need more information than
395 * that, such as chip type, configuration, associated IRQ, and so on.
397 * i2c_board_info is used to build tables of information listing I2C devices
398 * that are present. This information is used to grow the driver model tree.
399 * For mainboards this is done statically using i2c_register_board_info();
400 * bus numbers identify adapters that aren't yet available. For add-on boards,
401 * i2c_new_device() does this dynamically with the adapter already known.
403 struct i2c_board_info
{
404 char type
[I2C_NAME_SIZE
];
405 unsigned short flags
;
407 const char *dev_name
;
409 struct device_node
*of_node
;
410 struct fwnode_handle
*fwnode
;
411 const struct property_entry
*properties
;
412 const struct resource
*resources
;
413 unsigned int num_resources
;
418 * I2C_BOARD_INFO - macro used to list an i2c device and its address
419 * @dev_type: identifies the device type
420 * @dev_addr: the device's address on the bus.
422 * This macro initializes essential fields of a struct i2c_board_info,
423 * declaring what has been provided on a particular board. Optional
424 * fields (such as associated irq, or device-specific platform_data)
425 * are provided using conventional syntax.
427 #define I2C_BOARD_INFO(dev_type, dev_addr) \
428 .type = dev_type, .addr = (dev_addr)
431 #if IS_ENABLED(CONFIG_I2C)
432 /* Add-on boards should register/unregister their devices; e.g. a board
433 * with integrated I2C, a config eeprom, sensors, and a codec that's
434 * used in conjunction with the primary hardware.
436 extern struct i2c_client
*
437 i2c_new_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
439 /* If you don't know the exact address of an I2C device, use this variant
440 * instead, which can probe for device presence in a list of possible
441 * addresses. The "probe" callback function is optional. If it is provided,
442 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
443 * a default probing method is used.
445 extern struct i2c_client
*
446 i2c_new_probed_device(struct i2c_adapter
*adap
,
447 struct i2c_board_info
*info
,
448 unsigned short const *addr_list
,
449 int (*probe
)(struct i2c_adapter
*, unsigned short addr
));
451 /* Common custom probe functions */
452 extern int i2c_probe_func_quick_read(struct i2c_adapter
*, unsigned short addr
);
454 /* For devices that use several addresses, use i2c_new_dummy() to make
455 * client handles for the extra addresses.
457 extern struct i2c_client
*
458 i2c_new_dummy(struct i2c_adapter
*adap
, u16 address
);
460 extern struct i2c_client
*
461 devm_i2c_new_dummy_device(struct device
*dev
, struct i2c_adapter
*adap
, u16 address
);
463 extern struct i2c_client
*
464 i2c_new_secondary_device(struct i2c_client
*client
,
468 extern void i2c_unregister_device(struct i2c_client
*);
471 /* Mainboard arch_initcall() code should register all its I2C devices.
472 * This is done at arch_initcall time, before declaring any i2c adapters.
473 * Modules for add-on boards must use other calls.
475 #ifdef CONFIG_I2C_BOARDINFO
477 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
481 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
486 #endif /* I2C_BOARDINFO */
489 * struct i2c_algorithm - represent I2C transfer method
490 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
491 * defined by the msgs array, with num messages available to transfer via
492 * the adapter specified by adap.
493 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
494 * so e.g. PMICs can be accessed very late before shutdown. Optional.
495 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
496 * is not present, then the bus layer will try and convert the SMBus calls
497 * into I2C transfers instead.
498 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
499 * so e.g. PMICs can be accessed very late before shutdown. Optional.
500 * @functionality: Return the flags that this algorithm/adapter pair supports
501 * from the I2C_FUNC_* flags.
502 * @reg_slave: Register given client to I2C slave mode of this adapter
503 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
505 * The following structs are for those who like to implement new bus drivers:
506 * i2c_algorithm is the interface to a class of hardware solutions which can
507 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
508 * to name two of the most common.
510 * The return codes from the @master_xfer{_atomic} fields should indicate the
511 * type of error code that occurred during the transfer, as documented in the
512 * Kernel Documentation file Documentation/i2c/fault-codes.
514 struct i2c_algorithm
{
516 * If an adapter algorithm can't do I2C-level access, set master_xfer
517 * to NULL. If an adapter algorithm can do SMBus access, set
518 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
519 * using common I2C messages.
521 * master_xfer should return the number of messages successfully
522 * processed, or a negative value on error
524 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
526 int (*master_xfer_atomic
)(struct i2c_adapter
*adap
,
527 struct i2c_msg
*msgs
, 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 int (*smbus_xfer_atomic
)(struct i2c_adapter
*adap
, u16 addr
,
532 unsigned short flags
, char read_write
,
533 u8 command
, int size
, union i2c_smbus_data
*data
);
535 /* To determine what the adapter supports */
536 u32 (*functionality
)(struct i2c_adapter
*adap
);
538 #if IS_ENABLED(CONFIG_I2C_SLAVE)
539 int (*reg_slave
)(struct i2c_client
*client
);
540 int (*unreg_slave
)(struct i2c_client
*client
);
545 * struct i2c_lock_operations - represent I2C locking operations
546 * @lock_bus: Get exclusive access to an I2C bus segment
547 * @trylock_bus: Try to get exclusive access to an I2C bus segment
548 * @unlock_bus: Release exclusive access to an I2C bus segment
550 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
552 struct i2c_lock_operations
{
553 void (*lock_bus
)(struct i2c_adapter
*, unsigned int flags
);
554 int (*trylock_bus
)(struct i2c_adapter
*, unsigned int flags
);
555 void (*unlock_bus
)(struct i2c_adapter
*, unsigned int flags
);
559 * struct i2c_timings - I2C timing information
560 * @bus_freq_hz: the bus frequency in Hz
561 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
562 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
563 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
564 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
565 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
571 u32 scl_int_delay_ns
;
577 * struct i2c_bus_recovery_info - I2C bus recovery information
578 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
579 * i2c_generic_scl_recovery().
580 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
581 * recovery. Populated internally for generic GPIO recovery.
582 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
583 * Populated internally for generic GPIO recovery.
584 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
585 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
586 * GPIO, for generic GPIO recovery.
587 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
588 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
589 * for generic GPIO recovery.
590 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
591 * has a more complex internal logic than just reading SDA. Optional.
592 * @prepare_recovery: This will be called before starting recovery. Platform may
593 * configure padmux here for SDA/SCL line or something else they want.
594 * @unprepare_recovery: This will be called after completing recovery. Platform
595 * may configure padmux here for SDA/SCL line or something else they want.
596 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
597 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
599 struct i2c_bus_recovery_info
{
600 int (*recover_bus
)(struct i2c_adapter
*adap
);
602 int (*get_scl
)(struct i2c_adapter
*adap
);
603 void (*set_scl
)(struct i2c_adapter
*adap
, int val
);
604 int (*get_sda
)(struct i2c_adapter
*adap
);
605 void (*set_sda
)(struct i2c_adapter
*adap
, int val
);
606 int (*get_bus_free
)(struct i2c_adapter
*adap
);
608 void (*prepare_recovery
)(struct i2c_adapter
*adap
);
609 void (*unprepare_recovery
)(struct i2c_adapter
*adap
);
612 struct gpio_desc
*scl_gpiod
;
613 struct gpio_desc
*sda_gpiod
;
616 int i2c_recover_bus(struct i2c_adapter
*adap
);
618 /* Generic recovery routines */
619 int i2c_generic_scl_recovery(struct i2c_adapter
*adap
);
622 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
623 * @flags: see I2C_AQ_* for possible flags and read below
624 * @max_num_msgs: maximum number of messages per transfer
625 * @max_write_len: maximum length of a write message
626 * @max_read_len: maximum length of a read message
627 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
628 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
630 * Note about combined messages: Some I2C controllers can only send one message
631 * per transfer, plus something called combined message or write-then-read.
632 * This is (usually) a small write message followed by a read message and
633 * barely enough to access register based devices like EEPROMs. There is a flag
634 * to support this mode. It implies max_num_msg = 2 and does the length checks
635 * with max_comb_*_len because combined message mode usually has its own
636 * limitations. Because of HW implementations, some controllers can actually do
637 * write-then-anything or other variants. To support that, write-then-read has
638 * been broken out into smaller bits like write-first and read-second which can
639 * be combined as needed.
642 struct i2c_adapter_quirks
{
647 u16 max_comb_1st_msg_len
;
648 u16 max_comb_2nd_msg_len
;
651 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
652 #define I2C_AQ_COMB BIT(0)
653 /* first combined message must be write */
654 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
655 /* second combined message must be read */
656 #define I2C_AQ_COMB_READ_SECOND BIT(2)
657 /* both combined messages must have the same target address */
658 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
659 /* convenience macro for typical write-then read case */
660 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
661 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
662 /* clock stretching is not supported */
663 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
664 /* message cannot have length of 0 */
665 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
666 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
667 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
670 * i2c_adapter is the structure used to identify a physical i2c bus along
671 * with the access algorithms necessary to access it.
674 struct module
*owner
;
675 unsigned int class; /* classes to allow probing for */
676 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
679 /* data fields that are valid for all devices */
680 const struct i2c_lock_operations
*lock_ops
;
681 struct rt_mutex bus_lock
;
682 struct rt_mutex mux_lock
;
684 int timeout
; /* in jiffies */
686 struct device dev
; /* the adapter device */
687 unsigned long locked_flags
; /* owned by the I2C core */
688 #define I2C_ALF_IS_SUSPENDED 0
689 #define I2C_ALF_SUSPEND_REPORTED 1
693 struct completion dev_released
;
695 struct mutex userspace_clients_lock
;
696 struct list_head userspace_clients
;
698 struct i2c_bus_recovery_info
*bus_recovery_info
;
699 const struct i2c_adapter_quirks
*quirks
;
701 struct irq_domain
*host_notify_domain
;
703 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
705 static inline void *i2c_get_adapdata(const struct i2c_adapter
*dev
)
707 return dev_get_drvdata(&dev
->dev
);
710 static inline void i2c_set_adapdata(struct i2c_adapter
*dev
, void *data
)
712 dev_set_drvdata(&dev
->dev
, data
);
715 static inline struct i2c_adapter
*
716 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
718 #if IS_ENABLED(CONFIG_I2C_MUX)
719 struct device
*parent
= adapter
->dev
.parent
;
721 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
722 return to_i2c_adapter(parent
);
728 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*, void *));
730 /* Adapter locking functions, exported for shared pin cases */
731 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
732 #define I2C_LOCK_SEGMENT BIT(1)
735 * i2c_lock_bus - Get exclusive access to an I2C bus segment
736 * @adapter: Target I2C bus segment
737 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
738 * locks only this branch in the adapter tree
741 i2c_lock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
743 adapter
->lock_ops
->lock_bus(adapter
, flags
);
747 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
748 * @adapter: Target I2C bus segment
749 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
750 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
752 * Return: true if the I2C bus segment is locked, false otherwise
755 i2c_trylock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
757 return adapter
->lock_ops
->trylock_bus(adapter
, flags
);
761 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
762 * @adapter: Target I2C bus segment
763 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
764 * unlocks only this branch in the adapter tree
767 i2c_unlock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
769 adapter
->lock_ops
->unlock_bus(adapter
, flags
);
773 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
774 * @adap: Adapter to mark as suspended
776 * When using this helper to mark an adapter as suspended, the core will reject
777 * further transfers to this adapter. The usage of this helper is optional but
778 * recommended for devices having distinct handlers for system suspend and
779 * runtime suspend. More complex devices are free to implement custom solutions
780 * to reject transfers when suspended.
782 static inline void i2c_mark_adapter_suspended(struct i2c_adapter
*adap
)
784 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
785 set_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
786 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
790 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
791 * @adap: Adapter to mark as resumed
793 * When using this helper to mark an adapter as resumed, the core will allow
794 * further transfers to this adapter. See also further notes to
795 * @i2c_mark_adapter_suspended().
797 static inline void i2c_mark_adapter_resumed(struct i2c_adapter
*adap
)
799 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
800 clear_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
801 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
804 /*flags for the client struct: */
805 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
806 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
807 /* Must equal I2C_M_TEN below */
808 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
809 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
810 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
811 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
812 /* Must match I2C_M_STOP|IGNORE_NAK */
814 /* i2c adapter classes (bitmask) */
815 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
816 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
817 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
818 /* Warn users that the adapter doesn't support classes anymore */
819 #define I2C_CLASS_DEPRECATED (1<<8)
821 /* Internal numbers to terminate lists */
822 #define I2C_CLIENT_END 0xfffeU
824 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
825 #define I2C_ADDRS(addr, addrs...) \
826 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
829 /* ----- functions exported by i2c.o */
833 #if IS_ENABLED(CONFIG_I2C)
834 extern int i2c_add_adapter(struct i2c_adapter
*);
835 extern void i2c_del_adapter(struct i2c_adapter
*);
836 extern int i2c_add_numbered_adapter(struct i2c_adapter
*);
838 extern int i2c_register_driver(struct module
*, struct i2c_driver
*);
839 extern void i2c_del_driver(struct i2c_driver
*);
841 /* use a define to avoid include chaining to get THIS_MODULE */
842 #define i2c_add_driver(driver) \
843 i2c_register_driver(THIS_MODULE, driver)
845 extern struct i2c_client
*i2c_use_client(struct i2c_client
*client
);
846 extern void i2c_release_client(struct i2c_client
*client
);
848 /* call the i2c_client->command() of all attached clients with
849 * the given arguments */
850 extern void i2c_clients_command(struct i2c_adapter
*adap
,
851 unsigned int cmd
, void *arg
);
853 extern struct i2c_adapter
*i2c_get_adapter(int nr
);
854 extern void i2c_put_adapter(struct i2c_adapter
*adap
);
855 extern unsigned int i2c_adapter_depth(struct i2c_adapter
*adapter
);
857 void i2c_parse_fw_timings(struct device
*dev
, struct i2c_timings
*t
, bool use_defaults
);
859 /* Return the functionality mask */
860 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
862 return adap
->algo
->functionality(adap
);
865 /* Return 1 if adapter supports everything we need, 0 if not. */
866 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
868 return (func
& i2c_get_functionality(adap
)) == func
;
872 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
874 * @quirks: quirk flags
876 * Return: true if the adapter has all the specified quirk flags, false if not
878 static inline bool i2c_check_quirks(struct i2c_adapter
*adap
, u64 quirks
)
882 return (adap
->quirks
->flags
& quirks
) == quirks
;
885 /* Return the adapter number for a specific adapter */
886 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
891 static inline u8
i2c_8bit_addr_from_msg(const struct i2c_msg
*msg
)
893 return (msg
->addr
<< 1) | (msg
->flags
& I2C_M_RD
? 1 : 0);
896 u8
*i2c_get_dma_safe_msg_buf(struct i2c_msg
*msg
, unsigned int threshold
);
897 void i2c_put_dma_safe_msg_buf(u8
*buf
, struct i2c_msg
*msg
, bool xferred
);
899 int i2c_handle_smbus_host_notify(struct i2c_adapter
*adap
, unsigned short addr
);
901 * module_i2c_driver() - Helper macro for registering a modular I2C driver
902 * @__i2c_driver: i2c_driver struct
904 * Helper macro for I2C drivers which do not do anything special in module
905 * init/exit. This eliminates a lot of boilerplate. Each module may only
906 * use this macro once, and calling it replaces module_init() and module_exit()
908 #define module_i2c_driver(__i2c_driver) \
909 module_driver(__i2c_driver, i2c_add_driver, \
913 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
914 * @__i2c_driver: i2c_driver struct
916 * Helper macro for I2C drivers which do not do anything special in their
917 * init. This eliminates a lot of boilerplate. Each driver may only
918 * use this macro once, and calling it replaces device_initcall().
920 #define builtin_i2c_driver(__i2c_driver) \
921 builtin_driver(__i2c_driver, i2c_add_driver)
925 #if IS_ENABLED(CONFIG_OF)
926 /* must call put_device() when done with returned i2c_client device */
927 extern struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
);
929 /* must call put_device() when done with returned i2c_adapter device */
930 extern struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
);
932 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
933 struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
);
935 extern const struct of_device_id
936 *i2c_of_match_device(const struct of_device_id
*matches
,
937 struct i2c_client
*client
);
939 int of_i2c_get_board_info(struct device
*dev
, struct device_node
*node
,
940 struct i2c_board_info
*info
);
944 static inline struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
)
949 static inline struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
)
954 static inline struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
)
959 static inline const struct of_device_id
960 *i2c_of_match_device(const struct of_device_id
*matches
,
961 struct i2c_client
*client
)
966 static inline int of_i2c_get_board_info(struct device
*dev
,
967 struct device_node
*node
,
968 struct i2c_board_info
*info
)
973 #endif /* CONFIG_OF */
975 struct acpi_resource
;
976 struct acpi_resource_i2c_serialbus
;
978 #if IS_ENABLED(CONFIG_ACPI)
979 bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
980 struct acpi_resource_i2c_serialbus
**i2c
);
981 u32
i2c_acpi_find_bus_speed(struct device
*dev
);
982 struct i2c_client
*i2c_acpi_new_device(struct device
*dev
, int index
,
983 struct i2c_board_info
*info
);
985 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
986 struct acpi_resource_i2c_serialbus
**i2c
)
990 static inline u32
i2c_acpi_find_bus_speed(struct device
*dev
)
994 static inline struct i2c_client
*i2c_acpi_new_device(struct device
*dev
,
995 int index
, struct i2c_board_info
*info
)
999 #endif /* CONFIG_ACPI */
1001 #endif /* _LINUX_I2C_H */