1 /* SPDX-License-Identifier: GPL-2.0-or-later */
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>
7 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
8 * Frodo Looijaard <frodol@dds.nl>
13 #include <linux/acpi.h> /* for acpi_handle */
14 #include <linux/mod_devicetable.h>
15 #include <linux/device.h> /* for struct device */
16 #include <linux/sched.h> /* for completion */
17 #include <linux/mutex.h>
18 #include <linux/rtmutex.h>
19 #include <linux/irqdomain.h> /* for Host Notify IRQ */
20 #include <linux/of.h> /* for struct device_node */
21 #include <linux/swab.h> /* for swab16 */
22 #include <uapi/linux/i2c.h>
24 extern struct bus_type i2c_bus_type
;
25 extern struct device_type i2c_adapter_type
;
26 extern struct device_type i2c_client_type
;
28 /* --- General options ------------------------------------------------ */
35 struct i2c_device_identity
;
37 struct i2c_board_info
;
39 typedef int (*i2c_slave_cb_t
)(struct i2c_client
*client
,
40 enum i2c_slave_event event
, u8
*val
);
42 /* I2C Frequency Modes */
43 #define I2C_MAX_STANDARD_MODE_FREQ 100000
44 #define I2C_MAX_FAST_MODE_FREQ 400000
45 #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
46 #define I2C_MAX_TURBO_MODE_FREQ 1400000
47 #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
48 #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
51 struct property_entry
;
53 #if IS_ENABLED(CONFIG_I2C)
54 /* Return the Frequency mode string based on the bus frequency */
55 const char *i2c_freq_mode_string(u32 bus_freq_hz
);
58 * The master routines are the ones normally used to transmit data to devices
59 * on a bus (or read from them). Apart from two basic transfer functions to
60 * transmit one message at a time, a more complex version can be used to
61 * transmit an arbitrary number of messages without interruption.
62 * @count must be less than 64k since msg.len is u16.
64 int i2c_transfer_buffer_flags(const struct i2c_client
*client
,
65 char *buf
, int count
, u16 flags
);
68 * i2c_master_recv - issue a single I2C message in master receive mode
69 * @client: Handle to slave device
70 * @buf: Where to store data read from slave
71 * @count: How many bytes to read, must be less than 64k since msg.len is u16
73 * Returns negative errno, or else the number of bytes read.
75 static inline int i2c_master_recv(const struct i2c_client
*client
,
78 return i2c_transfer_buffer_flags(client
, buf
, count
, I2C_M_RD
);
82 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
83 * using a DMA safe buffer
84 * @client: Handle to slave device
85 * @buf: Where to store data read from slave, must be safe to use with DMA
86 * @count: How many bytes to read, must be less than 64k since msg.len is u16
88 * Returns negative errno, or else the number of bytes read.
90 static inline int i2c_master_recv_dmasafe(const struct i2c_client
*client
,
93 return i2c_transfer_buffer_flags(client
, buf
, count
,
94 I2C_M_RD
| I2C_M_DMA_SAFE
);
98 * i2c_master_send - issue a single I2C message in master transmit mode
99 * @client: Handle to slave device
100 * @buf: Data that will be written to the slave
101 * @count: How many bytes to write, must be less than 64k since msg.len is u16
103 * Returns negative errno, or else the number of bytes written.
105 static inline int i2c_master_send(const struct i2c_client
*client
,
106 const char *buf
, int count
)
108 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
, 0);
112 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
113 * using a DMA safe buffer
114 * @client: Handle to slave device
115 * @buf: Data that will be written to the slave, must be safe to use with DMA
116 * @count: How many bytes to write, must be less than 64k since msg.len is u16
118 * Returns negative errno, or else the number of bytes written.
120 static inline int i2c_master_send_dmasafe(const struct i2c_client
*client
,
121 const char *buf
, int count
)
123 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
,
127 /* Transfer num messages.
129 int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
130 /* Unlocked flavor */
131 int __i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
133 /* This is the very generalized SMBus access routine. You probably do not
134 want to use this, though; one of the functions below may be much easier,
135 and probably just as fast.
136 Note that we use i2c_adapter here, because you do not need a specific
137 smbus adapter to call this function. */
138 s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
139 unsigned short flags
, char read_write
, u8 command
,
140 int protocol
, union i2c_smbus_data
*data
);
142 /* Unlocked flavor */
143 s32
__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
);
147 /* Now follow the 'nice' access routines. These also document the calling
148 conventions of i2c_smbus_xfer. */
150 s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
151 s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
152 s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
, u8 command
);
153 s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
154 u8 command
, u8 value
);
155 s32
i2c_smbus_read_word_data(const struct i2c_client
*client
, u8 command
);
156 s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
157 u8 command
, u16 value
);
160 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
162 s32 value
= i2c_smbus_read_word_data(client
, command
);
164 return (value
< 0) ? value
: swab16(value
);
168 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
169 u8 command
, u16 value
)
171 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
174 /* Returns the number of read bytes */
175 s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
176 u8 command
, u8
*values
);
177 s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
178 u8 command
, u8 length
, const u8
*values
);
179 /* Returns the number of read bytes */
180 s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
181 u8 command
, u8 length
, u8
*values
);
182 s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
183 u8 command
, u8 length
, const u8
*values
);
184 s32
i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client
*client
,
185 u8 command
, u8 length
,
187 int i2c_get_device_id(const struct i2c_client
*client
,
188 struct i2c_device_identity
*id
);
192 * struct i2c_device_identity - i2c client device identification
193 * @manufacturer_id: 0 - 4095, database maintained by NXP
194 * @part_id: 0 - 511, according to manufacturer
195 * @die_revision: 0 - 7, according to manufacturer
197 struct i2c_device_identity
{
199 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
200 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
201 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
202 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
203 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
204 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
205 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
206 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
207 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
208 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
209 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
210 #define I2C_DEVICE_ID_FLIR 11
211 #define I2C_DEVICE_ID_O2MICRO 12
212 #define I2C_DEVICE_ID_ATMEL 13
213 #define I2C_DEVICE_ID_NONE 0xffff
218 enum i2c_alert_protocol
{
219 I2C_PROTOCOL_SMBUS_ALERT
,
220 I2C_PROTOCOL_SMBUS_HOST_NOTIFY
,
224 * struct i2c_driver - represent an I2C device driver
225 * @class: What kind of i2c device we instantiate (for detect)
226 * @probe: Callback for device binding - soon to be deprecated
227 * @probe_new: New callback for device binding
228 * @remove: Callback for device unbinding
229 * @shutdown: Callback for device shutdown
230 * @alert: Alert callback, for example for the SMBus alert protocol
231 * @command: Callback for bus-wide signaling (optional)
232 * @driver: Device driver model driver
233 * @id_table: List of I2C devices supported by this driver
234 * @detect: Callback for device detection
235 * @address_list: The I2C addresses to probe (for detect)
236 * @clients: List of detected clients we created (for i2c-core use only)
238 * The driver.owner field should be set to the module owner of this driver.
239 * The driver.name field should be set to the name of this driver.
241 * For automatic device detection, both @detect and @address_list must
242 * be defined. @class should also be set, otherwise only devices forced
243 * with module parameters will be created. The detect function must
244 * fill at least the name field of the i2c_board_info structure it is
245 * handed upon successful detection, and possibly also the flags field.
247 * If @detect is missing, the driver will still work fine for enumerated
248 * devices. Detected devices simply won't be supported. This is expected
249 * for the many I2C/SMBus devices which can't be detected reliably, and
250 * the ones which can always be enumerated in practice.
252 * The i2c_client structure which is handed to the @detect callback is
253 * not a real i2c_client. It is initialized just enough so that you can
254 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
255 * else with it. In particular, calling dev_dbg and friends on it is
261 /* Standard driver model interfaces */
262 int (*probe
)(struct i2c_client
*client
, const struct i2c_device_id
*id
);
263 int (*remove
)(struct i2c_client
*client
);
265 /* New driver model interface to aid the seamless removal of the
266 * current probe()'s, more commonly unused than used second parameter.
268 int (*probe_new
)(struct i2c_client
*client
);
270 /* driver model interfaces that don't relate to enumeration */
271 void (*shutdown
)(struct i2c_client
*client
);
273 /* Alert callback, for example for the SMBus alert protocol.
274 * The format and meaning of the data value depends on the protocol.
275 * For the SMBus alert protocol, there is a single bit of data passed
276 * as the alert response's low bit ("event flag").
277 * For the SMBus Host Notify protocol, the data corresponds to the
278 * 16-bit payload data reported by the slave device acting as master.
280 void (*alert
)(struct i2c_client
*client
, enum i2c_alert_protocol protocol
,
283 /* a ioctl like command that can be used to perform specific functions
286 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
288 struct device_driver driver
;
289 const struct i2c_device_id
*id_table
;
291 /* Device detection callback for automatic device creation */
292 int (*detect
)(struct i2c_client
*client
, struct i2c_board_info
*info
);
293 const unsigned short *address_list
;
294 struct list_head clients
;
296 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
299 * struct i2c_client - represent an I2C slave device
300 * @flags: see I2C_CLIENT_* for possible flags
301 * @addr: Address used on the I2C bus connected to the parent adapter.
302 * @name: Indicates the type of the device, usually a chip name that's
303 * generic enough to hide second-sourcing and compatible revisions.
304 * @adapter: manages the bus segment hosting this I2C device
305 * @dev: Driver model device node for the slave.
306 * @init_irq: IRQ that was set at initialization
307 * @irq: indicates the IRQ generated by this device (if any)
308 * @detected: member of an i2c_driver.clients list or i2c-core's
309 * userspace_devices list
310 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
311 * calls it to pass on slave events to the slave driver.
312 * @devres_group_id: id of the devres group that will be created for resources
313 * acquired when probing this device.
315 * An i2c_client identifies a single device (i.e. chip) connected to an
316 * i2c bus. The behaviour exposed to Linux is defined by the driver
317 * managing the device.
320 unsigned short flags
; /* div., see below */
321 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
322 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
323 /* Must equal I2C_M_TEN below */
324 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
325 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
326 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
327 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
328 /* Must match I2C_M_STOP|IGNORE_NAK */
330 unsigned short addr
; /* chip address - NOTE: 7bit */
331 /* addresses are stored in the */
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 */
342 void *devres_group_id
; /* ID of probe devres group */
344 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
346 struct i2c_client
*i2c_verify_client(struct device
*dev
);
347 struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
348 const struct i2c_device_id
*i2c_match_id(const struct i2c_device_id
*id
,
349 const struct i2c_client
*client
);
351 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
353 struct device
* const dev
= kobj_to_dev(kobj
);
354 return to_i2c_client(dev
);
357 static inline void *i2c_get_clientdata(const struct i2c_client
*client
)
359 return dev_get_drvdata(&client
->dev
);
362 static inline void i2c_set_clientdata(struct i2c_client
*client
, void *data
)
364 dev_set_drvdata(&client
->dev
, data
);
367 /* I2C slave support */
369 #if IS_ENABLED(CONFIG_I2C_SLAVE)
370 enum i2c_slave_event
{
371 I2C_SLAVE_READ_REQUESTED
,
372 I2C_SLAVE_WRITE_REQUESTED
,
373 I2C_SLAVE_READ_PROCESSED
,
374 I2C_SLAVE_WRITE_RECEIVED
,
378 int i2c_slave_register(struct i2c_client
*client
, i2c_slave_cb_t slave_cb
);
379 int i2c_slave_unregister(struct i2c_client
*client
);
380 bool i2c_detect_slave_mode(struct device
*dev
);
382 static inline int i2c_slave_event(struct i2c_client
*client
,
383 enum i2c_slave_event event
, u8
*val
)
385 return client
->slave_cb(client
, event
, val
);
388 static inline bool i2c_detect_slave_mode(struct device
*dev
) { return false; }
392 * struct i2c_board_info - template for device creation
393 * @type: chip type, to initialize i2c_client.name
394 * @flags: to initialize i2c_client.flags
395 * @addr: stored in i2c_client.addr
396 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
397 * @platform_data: stored in i2c_client.dev.platform_data
398 * @of_node: pointer to OpenFirmware device node
399 * @fwnode: device node supplied by the platform firmware
400 * @swnode: software node for the device
401 * @resources: resources associated with the device
402 * @num_resources: number of resources in the @resources array
403 * @irq: stored in i2c_client.irq
405 * I2C doesn't actually support hardware probing, although controllers and
406 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
407 * a device at a given address. Drivers commonly need more information than
408 * that, such as chip type, configuration, associated IRQ, and so on.
410 * i2c_board_info is used to build tables of information listing I2C devices
411 * that are present. This information is used to grow the driver model tree.
412 * For mainboards this is done statically using i2c_register_board_info();
413 * bus numbers identify adapters that aren't yet available. For add-on boards,
414 * i2c_new_client_device() does this dynamically with the adapter already known.
416 struct i2c_board_info
{
417 char type
[I2C_NAME_SIZE
];
418 unsigned short flags
;
420 const char *dev_name
;
422 struct device_node
*of_node
;
423 struct fwnode_handle
*fwnode
;
424 const struct software_node
*swnode
;
425 const struct resource
*resources
;
426 unsigned int num_resources
;
431 * I2C_BOARD_INFO - macro used to list an i2c device and its address
432 * @dev_type: identifies the device type
433 * @dev_addr: the device's address on the bus.
435 * This macro initializes essential fields of a struct i2c_board_info,
436 * declaring what has been provided on a particular board. Optional
437 * fields (such as associated irq, or device-specific platform_data)
438 * are provided using conventional syntax.
440 #define I2C_BOARD_INFO(dev_type, dev_addr) \
441 .type = dev_type, .addr = (dev_addr)
444 #if IS_ENABLED(CONFIG_I2C)
446 * Add-on boards should register/unregister their devices; e.g. a board
447 * with integrated I2C, a config eeprom, sensors, and a codec that's
448 * used in conjunction with the primary hardware.
451 i2c_new_client_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
453 /* If you don't know the exact address of an I2C device, use this variant
454 * instead, which can probe for device presence in a list of possible
455 * addresses. The "probe" callback function is optional. If it is provided,
456 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
457 * a default probing method is used.
460 i2c_new_scanned_device(struct i2c_adapter
*adap
,
461 struct i2c_board_info
*info
,
462 unsigned short const *addr_list
,
463 int (*probe
)(struct i2c_adapter
*adap
, unsigned short addr
));
465 /* Common custom probe functions */
466 int i2c_probe_func_quick_read(struct i2c_adapter
*adap
, unsigned short addr
);
469 i2c_new_dummy_device(struct i2c_adapter
*adapter
, u16 address
);
472 devm_i2c_new_dummy_device(struct device
*dev
, struct i2c_adapter
*adap
, u16 address
);
475 i2c_new_ancillary_device(struct i2c_client
*client
,
479 void i2c_unregister_device(struct i2c_client
*client
);
482 /* Mainboard arch_initcall() code should register all its I2C devices.
483 * This is done at arch_initcall time, before declaring any i2c adapters.
484 * Modules for add-on boards must use other calls.
486 #ifdef CONFIG_I2C_BOARDINFO
488 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
492 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
497 #endif /* I2C_BOARDINFO */
500 * struct i2c_algorithm - represent I2C transfer method
501 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
502 * defined by the msgs array, with num messages available to transfer via
503 * the adapter specified by adap.
504 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
505 * so e.g. PMICs can be accessed very late before shutdown. Optional.
506 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
507 * is not present, then the bus layer will try and convert the SMBus calls
508 * into I2C transfers instead.
509 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
510 * so e.g. PMICs can be accessed very late before shutdown. Optional.
511 * @functionality: Return the flags that this algorithm/adapter pair supports
512 * from the ``I2C_FUNC_*`` flags.
513 * @reg_slave: Register given client to I2C slave mode of this adapter
514 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
516 * The following structs are for those who like to implement new bus drivers:
517 * i2c_algorithm is the interface to a class of hardware solutions which can
518 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
519 * to name two of the most common.
521 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
522 * type of error code that occurred during the transfer, as documented in the
523 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
525 struct i2c_algorithm
{
527 * If an adapter algorithm can't do I2C-level access, set master_xfer
528 * to NULL. If an adapter algorithm can do SMBus access, set
529 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
530 * using common I2C messages.
532 * master_xfer should return the number of messages successfully
533 * processed, or a negative value on error
535 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
537 int (*master_xfer_atomic
)(struct i2c_adapter
*adap
,
538 struct i2c_msg
*msgs
, int num
);
539 int (*smbus_xfer
)(struct i2c_adapter
*adap
, u16 addr
,
540 unsigned short flags
, char read_write
,
541 u8 command
, int size
, union i2c_smbus_data
*data
);
542 int (*smbus_xfer_atomic
)(struct i2c_adapter
*adap
, u16 addr
,
543 unsigned short flags
, char read_write
,
544 u8 command
, int size
, union i2c_smbus_data
*data
);
546 /* To determine what the adapter supports */
547 u32 (*functionality
)(struct i2c_adapter
*adap
);
549 #if IS_ENABLED(CONFIG_I2C_SLAVE)
550 int (*reg_slave
)(struct i2c_client
*client
);
551 int (*unreg_slave
)(struct i2c_client
*client
);
556 * struct i2c_lock_operations - represent I2C locking operations
557 * @lock_bus: Get exclusive access to an I2C bus segment
558 * @trylock_bus: Try to get exclusive access to an I2C bus segment
559 * @unlock_bus: Release exclusive access to an I2C bus segment
561 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
563 struct i2c_lock_operations
{
564 void (*lock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
565 int (*trylock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
566 void (*unlock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
570 * struct i2c_timings - I2C timing information
571 * @bus_freq_hz: the bus frequency in Hz
572 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
573 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
574 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
575 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
576 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
577 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
578 * digital filter can filter out
579 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
586 u32 scl_int_delay_ns
;
589 u32 digital_filter_width_ns
;
590 u32 analog_filter_cutoff_freq_hz
;
594 * struct i2c_bus_recovery_info - I2C bus recovery information
595 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
596 * i2c_generic_scl_recovery().
597 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
598 * recovery. Populated internally for generic GPIO recovery.
599 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
600 * Populated internally for generic GPIO recovery.
601 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
602 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
603 * GPIO, for generic GPIO recovery.
604 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
605 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
606 * for generic GPIO recovery.
607 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
608 * has a more complex internal logic than just reading SDA. Optional.
609 * @prepare_recovery: This will be called before starting recovery. Platform may
610 * configure padmux here for SDA/SCL line or something else they want.
611 * @unprepare_recovery: This will be called after completing recovery. Platform
612 * may configure padmux here for SDA/SCL line or something else they want.
613 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
614 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
615 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
617 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
618 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
619 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
620 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
621 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
622 * is called "gpio" or "recovery" and pinctrl is valid.
624 struct i2c_bus_recovery_info
{
625 int (*recover_bus
)(struct i2c_adapter
*adap
);
627 int (*get_scl
)(struct i2c_adapter
*adap
);
628 void (*set_scl
)(struct i2c_adapter
*adap
, int val
);
629 int (*get_sda
)(struct i2c_adapter
*adap
);
630 void (*set_sda
)(struct i2c_adapter
*adap
, int val
);
631 int (*get_bus_free
)(struct i2c_adapter
*adap
);
633 void (*prepare_recovery
)(struct i2c_adapter
*adap
);
634 void (*unprepare_recovery
)(struct i2c_adapter
*adap
);
637 struct gpio_desc
*scl_gpiod
;
638 struct gpio_desc
*sda_gpiod
;
639 struct pinctrl
*pinctrl
;
640 struct pinctrl_state
*pins_default
;
641 struct pinctrl_state
*pins_gpio
;
644 int i2c_recover_bus(struct i2c_adapter
*adap
);
646 /* Generic recovery routines */
647 int i2c_generic_scl_recovery(struct i2c_adapter
*adap
);
650 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
651 * @flags: see I2C_AQ_* for possible flags and read below
652 * @max_num_msgs: maximum number of messages per transfer
653 * @max_write_len: maximum length of a write message
654 * @max_read_len: maximum length of a read message
655 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
656 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
658 * Note about combined messages: Some I2C controllers can only send one message
659 * per transfer, plus something called combined message or write-then-read.
660 * This is (usually) a small write message followed by a read message and
661 * barely enough to access register based devices like EEPROMs. There is a flag
662 * to support this mode. It implies max_num_msg = 2 and does the length checks
663 * with max_comb_*_len because combined message mode usually has its own
664 * limitations. Because of HW implementations, some controllers can actually do
665 * write-then-anything or other variants. To support that, write-then-read has
666 * been broken out into smaller bits like write-first and read-second which can
667 * be combined as needed.
670 struct i2c_adapter_quirks
{
675 u16 max_comb_1st_msg_len
;
676 u16 max_comb_2nd_msg_len
;
679 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
680 #define I2C_AQ_COMB BIT(0)
681 /* first combined message must be write */
682 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
683 /* second combined message must be read */
684 #define I2C_AQ_COMB_READ_SECOND BIT(2)
685 /* both combined messages must have the same target address */
686 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
687 /* convenience macro for typical write-then read case */
688 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
689 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
690 /* clock stretching is not supported */
691 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
692 /* message cannot have length of 0 */
693 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
694 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
695 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
696 /* adapter cannot do repeated START */
697 #define I2C_AQ_NO_REP_START BIT(7)
700 * i2c_adapter is the structure used to identify a physical i2c bus along
701 * with the access algorithms necessary to access it.
704 struct module
*owner
;
705 unsigned int class; /* classes to allow probing for */
706 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
709 /* data fields that are valid for all devices */
710 const struct i2c_lock_operations
*lock_ops
;
711 struct rt_mutex bus_lock
;
712 struct rt_mutex mux_lock
;
714 int timeout
; /* in jiffies */
716 struct device dev
; /* the adapter device */
717 unsigned long locked_flags
; /* owned by the I2C core */
718 #define I2C_ALF_IS_SUSPENDED 0
719 #define I2C_ALF_SUSPEND_REPORTED 1
723 struct completion dev_released
;
725 struct mutex userspace_clients_lock
;
726 struct list_head userspace_clients
;
728 struct i2c_bus_recovery_info
*bus_recovery_info
;
729 const struct i2c_adapter_quirks
*quirks
;
731 struct irq_domain
*host_notify_domain
;
733 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
735 static inline void *i2c_get_adapdata(const struct i2c_adapter
*adap
)
737 return dev_get_drvdata(&adap
->dev
);
740 static inline void i2c_set_adapdata(struct i2c_adapter
*adap
, void *data
)
742 dev_set_drvdata(&adap
->dev
, data
);
745 static inline struct i2c_adapter
*
746 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
748 #if IS_ENABLED(CONFIG_I2C_MUX)
749 struct device
*parent
= adapter
->dev
.parent
;
751 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
752 return to_i2c_adapter(parent
);
758 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*dev
, void *data
));
760 /* Adapter locking functions, exported for shared pin cases */
761 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
762 #define I2C_LOCK_SEGMENT BIT(1)
765 * i2c_lock_bus - Get exclusive access to an I2C bus segment
766 * @adapter: Target I2C bus segment
767 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
768 * locks only this branch in the adapter tree
771 i2c_lock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
773 adapter
->lock_ops
->lock_bus(adapter
, flags
);
777 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
778 * @adapter: Target I2C bus segment
779 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
780 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
782 * Return: true if the I2C bus segment is locked, false otherwise
785 i2c_trylock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
787 return adapter
->lock_ops
->trylock_bus(adapter
, flags
);
791 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
792 * @adapter: Target I2C bus segment
793 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
794 * unlocks only this branch in the adapter tree
797 i2c_unlock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
799 adapter
->lock_ops
->unlock_bus(adapter
, flags
);
803 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
804 * @adap: Adapter to mark as suspended
806 * When using this helper to mark an adapter as suspended, the core will reject
807 * further transfers to this adapter. The usage of this helper is optional but
808 * recommended for devices having distinct handlers for system suspend and
809 * runtime suspend. More complex devices are free to implement custom solutions
810 * to reject transfers when suspended.
812 static inline void i2c_mark_adapter_suspended(struct i2c_adapter
*adap
)
814 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
815 set_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
816 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
820 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
821 * @adap: Adapter to mark as resumed
823 * When using this helper to mark an adapter as resumed, the core will allow
824 * further transfers to this adapter. See also further notes to
825 * @i2c_mark_adapter_suspended().
827 static inline void i2c_mark_adapter_resumed(struct i2c_adapter
*adap
)
829 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
830 clear_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
831 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
834 /* i2c adapter classes (bitmask) */
835 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
836 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
837 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
838 /* Warn users that the adapter doesn't support classes anymore */
839 #define I2C_CLASS_DEPRECATED (1<<8)
841 /* Internal numbers to terminate lists */
842 #define I2C_CLIENT_END 0xfffeU
844 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
845 #define I2C_ADDRS(addr, addrs...) \
846 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
849 /* ----- functions exported by i2c.o */
853 #if IS_ENABLED(CONFIG_I2C)
854 int i2c_add_adapter(struct i2c_adapter
*adap
);
855 int devm_i2c_add_adapter(struct device
*dev
, struct i2c_adapter
*adapter
);
856 void i2c_del_adapter(struct i2c_adapter
*adap
);
857 int i2c_add_numbered_adapter(struct i2c_adapter
*adap
);
859 int i2c_register_driver(struct module
*owner
, struct i2c_driver
*driver
);
860 void i2c_del_driver(struct i2c_driver
*driver
);
862 /* use a define to avoid include chaining to get THIS_MODULE */
863 #define i2c_add_driver(driver) \
864 i2c_register_driver(THIS_MODULE, driver)
866 static inline bool i2c_client_has_driver(struct i2c_client
*client
)
868 return !IS_ERR_OR_NULL(client
) && client
->dev
.driver
;
871 /* call the i2c_client->command() of all attached clients with
872 * the given arguments */
873 void i2c_clients_command(struct i2c_adapter
*adap
,
874 unsigned int cmd
, void *arg
);
876 struct i2c_adapter
*i2c_get_adapter(int nr
);
877 void i2c_put_adapter(struct i2c_adapter
*adap
);
878 unsigned int i2c_adapter_depth(struct i2c_adapter
*adapter
);
880 void i2c_parse_fw_timings(struct device
*dev
, struct i2c_timings
*t
, bool use_defaults
);
882 /* Return the functionality mask */
883 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
885 return adap
->algo
->functionality(adap
);
888 /* Return 1 if adapter supports everything we need, 0 if not. */
889 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
891 return (func
& i2c_get_functionality(adap
)) == func
;
895 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
897 * @quirks: quirk flags
899 * Return: true if the adapter has all the specified quirk flags, false if not
901 static inline bool i2c_check_quirks(struct i2c_adapter
*adap
, u64 quirks
)
905 return (adap
->quirks
->flags
& quirks
) == quirks
;
908 /* Return the adapter number for a specific adapter */
909 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
914 static inline u8
i2c_8bit_addr_from_msg(const struct i2c_msg
*msg
)
916 return (msg
->addr
<< 1) | (msg
->flags
& I2C_M_RD
? 1 : 0);
919 u8
*i2c_get_dma_safe_msg_buf(struct i2c_msg
*msg
, unsigned int threshold
);
920 void i2c_put_dma_safe_msg_buf(u8
*buf
, struct i2c_msg
*msg
, bool xferred
);
922 int i2c_handle_smbus_host_notify(struct i2c_adapter
*adap
, unsigned short addr
);
924 * module_i2c_driver() - Helper macro for registering a modular I2C driver
925 * @__i2c_driver: i2c_driver struct
927 * Helper macro for I2C drivers which do not do anything special in module
928 * init/exit. This eliminates a lot of boilerplate. Each module may only
929 * use this macro once, and calling it replaces module_init() and module_exit()
931 #define module_i2c_driver(__i2c_driver) \
932 module_driver(__i2c_driver, i2c_add_driver, \
936 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
937 * @__i2c_driver: i2c_driver struct
939 * Helper macro for I2C drivers which do not do anything special in their
940 * init. This eliminates a lot of boilerplate. Each driver may only
941 * use this macro once, and calling it replaces device_initcall().
943 #define builtin_i2c_driver(__i2c_driver) \
944 builtin_driver(__i2c_driver, i2c_add_driver)
948 #if IS_ENABLED(CONFIG_OF)
949 /* must call put_device() when done with returned i2c_client device */
950 struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
);
952 /* must call put_device() when done with returned i2c_adapter device */
953 struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
);
955 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
956 struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
);
958 const struct of_device_id
959 *i2c_of_match_device(const struct of_device_id
*matches
,
960 struct i2c_client
*client
);
962 int of_i2c_get_board_info(struct device
*dev
, struct device_node
*node
,
963 struct i2c_board_info
*info
);
967 static inline struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
)
972 static inline struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
)
977 static inline struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
)
982 static inline const struct of_device_id
983 *i2c_of_match_device(const struct of_device_id
*matches
,
984 struct i2c_client
*client
)
989 static inline int of_i2c_get_board_info(struct device
*dev
,
990 struct device_node
*node
,
991 struct i2c_board_info
*info
)
996 #endif /* CONFIG_OF */
998 struct acpi_resource
;
999 struct acpi_resource_i2c_serialbus
;
1001 #if IS_ENABLED(CONFIG_ACPI)
1002 bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
1003 struct acpi_resource_i2c_serialbus
**i2c
);
1004 u32
i2c_acpi_find_bus_speed(struct device
*dev
);
1005 struct i2c_client
*i2c_acpi_new_device(struct device
*dev
, int index
,
1006 struct i2c_board_info
*info
);
1007 struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
);
1009 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
1010 struct acpi_resource_i2c_serialbus
**i2c
)
1014 static inline u32
i2c_acpi_find_bus_speed(struct device
*dev
)
1018 static inline struct i2c_client
*i2c_acpi_new_device(struct device
*dev
,
1019 int index
, struct i2c_board_info
*info
)
1021 return ERR_PTR(-ENODEV
);
1023 static inline struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
)
1027 #endif /* CONFIG_ACPI */
1029 #endif /* _LINUX_I2C_H */