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/regulator/consumer.h>
19 #include <linux/rtmutex.h>
20 #include <linux/irqdomain.h> /* for Host Notify IRQ */
21 #include <linux/of.h> /* for struct device_node */
22 #include <linux/swab.h> /* for swab16 */
23 #include <uapi/linux/i2c.h>
25 extern struct bus_type i2c_bus_type
;
26 extern struct device_type i2c_adapter_type
;
27 extern struct device_type i2c_client_type
;
29 /* --- General options ------------------------------------------------ */
36 struct i2c_device_identity
;
38 struct i2c_board_info
;
40 typedef int (*i2c_slave_cb_t
)(struct i2c_client
*client
,
41 enum i2c_slave_event event
, u8
*val
);
43 /* I2C Frequency Modes */
44 #define I2C_MAX_STANDARD_MODE_FREQ 100000
45 #define I2C_MAX_FAST_MODE_FREQ 400000
46 #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
47 #define I2C_MAX_TURBO_MODE_FREQ 1400000
48 #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
49 #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
52 struct property_entry
;
54 #if IS_ENABLED(CONFIG_I2C)
55 /* Return the Frequency mode string based on the bus frequency */
56 const char *i2c_freq_mode_string(u32 bus_freq_hz
);
59 * The master routines are the ones normally used to transmit data to devices
60 * on a bus (or read from them). Apart from two basic transfer functions to
61 * transmit one message at a time, a more complex version can be used to
62 * transmit an arbitrary number of messages without interruption.
63 * @count must be less than 64k since msg.len is u16.
65 int i2c_transfer_buffer_flags(const struct i2c_client
*client
,
66 char *buf
, int count
, u16 flags
);
69 * i2c_master_recv - issue a single I2C message in master receive mode
70 * @client: Handle to slave device
71 * @buf: Where to store data read from slave
72 * @count: How many bytes to read, must be less than 64k since msg.len is u16
74 * Returns negative errno, or else the number of bytes read.
76 static inline int i2c_master_recv(const struct i2c_client
*client
,
79 return i2c_transfer_buffer_flags(client
, buf
, count
, I2C_M_RD
);
83 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
84 * using a DMA safe buffer
85 * @client: Handle to slave device
86 * @buf: Where to store data read from slave, must be safe to use with DMA
87 * @count: How many bytes to read, must be less than 64k since msg.len is u16
89 * Returns negative errno, or else the number of bytes read.
91 static inline int i2c_master_recv_dmasafe(const struct i2c_client
*client
,
94 return i2c_transfer_buffer_flags(client
, buf
, count
,
95 I2C_M_RD
| I2C_M_DMA_SAFE
);
99 * i2c_master_send - issue a single I2C message in master transmit mode
100 * @client: Handle to slave device
101 * @buf: Data that will be written to the slave
102 * @count: How many bytes to write, must be less than 64k since msg.len is u16
104 * Returns negative errno, or else the number of bytes written.
106 static inline int i2c_master_send(const struct i2c_client
*client
,
107 const char *buf
, int count
)
109 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
, 0);
113 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
114 * using a DMA safe buffer
115 * @client: Handle to slave device
116 * @buf: Data that will be written to the slave, must be safe to use with DMA
117 * @count: How many bytes to write, must be less than 64k since msg.len is u16
119 * Returns negative errno, or else the number of bytes written.
121 static inline int i2c_master_send_dmasafe(const struct i2c_client
*client
,
122 const char *buf
, int count
)
124 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
,
128 /* Transfer num messages.
130 int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
131 /* Unlocked flavor */
132 int __i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
134 /* This is the very generalized SMBus access routine. You probably do not
135 want to use this, though; one of the functions below may be much easier,
136 and probably just as fast.
137 Note that we use i2c_adapter here, because you do not need a specific
138 smbus adapter to call this function. */
139 s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
140 unsigned short flags
, char read_write
, u8 command
,
141 int protocol
, union i2c_smbus_data
*data
);
143 /* Unlocked flavor */
144 s32
__i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
145 unsigned short flags
, char read_write
, u8 command
,
146 int protocol
, union i2c_smbus_data
*data
);
148 /* Now follow the 'nice' access routines. These also document the calling
149 conventions of i2c_smbus_xfer. */
151 u8
i2c_smbus_pec(u8 crc
, u8
*p
, size_t count
);
152 s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
153 s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
154 s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
, u8 command
);
155 s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
156 u8 command
, u8 value
);
157 s32
i2c_smbus_read_word_data(const struct i2c_client
*client
, u8 command
);
158 s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
159 u8 command
, u16 value
);
162 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
164 s32 value
= i2c_smbus_read_word_data(client
, command
);
166 return (value
< 0) ? value
: swab16(value
);
170 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
171 u8 command
, u16 value
)
173 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
176 /* Returns the number of read bytes */
177 s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
178 u8 command
, u8
*values
);
179 s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
180 u8 command
, u8 length
, const u8
*values
);
181 /* Returns the number of read bytes */
182 s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
183 u8 command
, u8 length
, u8
*values
);
184 s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
185 u8 command
, u8 length
, const u8
*values
);
186 s32
i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client
*client
,
187 u8 command
, u8 length
,
189 int i2c_get_device_id(const struct i2c_client
*client
,
190 struct i2c_device_identity
*id
);
194 * struct i2c_device_identity - i2c client device identification
195 * @manufacturer_id: 0 - 4095, database maintained by NXP
196 * @part_id: 0 - 511, according to manufacturer
197 * @die_revision: 0 - 7, according to manufacturer
199 struct i2c_device_identity
{
201 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
202 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
203 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
204 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
205 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
206 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
207 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
208 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
209 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
210 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
211 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
212 #define I2C_DEVICE_ID_FLIR 11
213 #define I2C_DEVICE_ID_O2MICRO 12
214 #define I2C_DEVICE_ID_ATMEL 13
215 #define I2C_DEVICE_ID_NONE 0xffff
220 enum i2c_alert_protocol
{
221 I2C_PROTOCOL_SMBUS_ALERT
,
222 I2C_PROTOCOL_SMBUS_HOST_NOTIFY
,
226 * struct i2c_driver - represent an I2C device driver
227 * @class: What kind of i2c device we instantiate (for detect)
228 * @probe: Callback for device binding - soon to be deprecated
229 * @probe_new: New callback for device binding
230 * @remove: Callback for device unbinding
231 * @shutdown: Callback for device shutdown
232 * @alert: Alert callback, for example for the SMBus alert protocol
233 * @command: Callback for bus-wide signaling (optional)
234 * @driver: Device driver model driver
235 * @id_table: List of I2C devices supported by this driver
236 * @detect: Callback for device detection
237 * @address_list: The I2C addresses to probe (for detect)
238 * @clients: List of detected clients we created (for i2c-core use only)
240 * The driver.owner field should be set to the module owner of this driver.
241 * The driver.name field should be set to the name of this driver.
243 * For automatic device detection, both @detect and @address_list must
244 * be defined. @class should also be set, otherwise only devices forced
245 * with module parameters will be created. The detect function must
246 * fill at least the name field of the i2c_board_info structure it is
247 * handed upon successful detection, and possibly also the flags field.
249 * If @detect is missing, the driver will still work fine for enumerated
250 * devices. Detected devices simply won't be supported. This is expected
251 * for the many I2C/SMBus devices which can't be detected reliably, and
252 * the ones which can always be enumerated in practice.
254 * The i2c_client structure which is handed to the @detect callback is
255 * not a real i2c_client. It is initialized just enough so that you can
256 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
257 * else with it. In particular, calling dev_dbg and friends on it is
263 /* Standard driver model interfaces */
264 int (*probe
)(struct i2c_client
*client
, const struct i2c_device_id
*id
);
265 int (*remove
)(struct i2c_client
*client
);
267 /* New driver model interface to aid the seamless removal of the
268 * current probe()'s, more commonly unused than used second parameter.
270 int (*probe_new
)(struct i2c_client
*client
);
272 /* driver model interfaces that don't relate to enumeration */
273 void (*shutdown
)(struct i2c_client
*client
);
275 /* Alert callback, for example for the SMBus alert protocol.
276 * The format and meaning of the data value depends on the protocol.
277 * For the SMBus alert protocol, there is a single bit of data passed
278 * as the alert response's low bit ("event flag").
279 * For the SMBus Host Notify protocol, the data corresponds to the
280 * 16-bit payload data reported by the slave device acting as master.
282 void (*alert
)(struct i2c_client
*client
, enum i2c_alert_protocol protocol
,
285 /* a ioctl like command that can be used to perform specific functions
288 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
290 struct device_driver driver
;
291 const struct i2c_device_id
*id_table
;
293 /* Device detection callback for automatic device creation */
294 int (*detect
)(struct i2c_client
*client
, struct i2c_board_info
*info
);
295 const unsigned short *address_list
;
296 struct list_head clients
;
298 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
301 * struct i2c_client - represent an I2C slave device
302 * @flags: see I2C_CLIENT_* for possible flags
303 * @addr: Address used on the I2C bus connected to the parent adapter.
304 * @name: Indicates the type of the device, usually a chip name that's
305 * generic enough to hide second-sourcing and compatible revisions.
306 * @adapter: manages the bus segment hosting this I2C device
307 * @dev: Driver model device node for the slave.
308 * @init_irq: IRQ that was set at initialization
309 * @irq: indicates the IRQ generated by this device (if any)
310 * @detected: member of an i2c_driver.clients list or i2c-core's
311 * userspace_devices list
312 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
313 * calls it to pass on slave events to the slave driver.
314 * @devres_group_id: id of the devres group that will be created for resources
315 * acquired when probing this device.
317 * An i2c_client identifies a single device (i.e. chip) connected to an
318 * i2c bus. The behaviour exposed to Linux is defined by the driver
319 * managing the device.
322 unsigned short flags
; /* div., see below */
323 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
324 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
325 /* Must equal I2C_M_TEN below */
326 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
327 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
328 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
329 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
330 /* Must match I2C_M_STOP|IGNORE_NAK */
332 unsigned short addr
; /* chip address - NOTE: 7bit */
333 /* addresses are stored in the */
335 char name
[I2C_NAME_SIZE
];
336 struct i2c_adapter
*adapter
; /* the adapter we sit on */
337 struct device dev
; /* the device structure */
338 int init_irq
; /* irq set at initialization */
339 int irq
; /* irq issued by device */
340 struct list_head detected
;
341 #if IS_ENABLED(CONFIG_I2C_SLAVE)
342 i2c_slave_cb_t slave_cb
; /* callback for slave mode */
344 void *devres_group_id
; /* ID of probe devres group */
346 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
348 struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
349 const struct i2c_device_id
*i2c_match_id(const struct i2c_device_id
*id
,
350 const struct i2c_client
*client
);
352 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
354 struct device
* const dev
= kobj_to_dev(kobj
);
355 return to_i2c_client(dev
);
358 static inline void *i2c_get_clientdata(const struct i2c_client
*client
)
360 return dev_get_drvdata(&client
->dev
);
363 static inline void i2c_set_clientdata(struct i2c_client
*client
, void *data
)
365 dev_set_drvdata(&client
->dev
, data
);
368 /* I2C slave support */
370 #if IS_ENABLED(CONFIG_I2C_SLAVE)
371 enum i2c_slave_event
{
372 I2C_SLAVE_READ_REQUESTED
,
373 I2C_SLAVE_WRITE_REQUESTED
,
374 I2C_SLAVE_READ_PROCESSED
,
375 I2C_SLAVE_WRITE_RECEIVED
,
379 int i2c_slave_register(struct i2c_client
*client
, i2c_slave_cb_t slave_cb
);
380 int i2c_slave_unregister(struct i2c_client
*client
);
381 bool i2c_detect_slave_mode(struct device
*dev
);
383 static inline int i2c_slave_event(struct i2c_client
*client
,
384 enum i2c_slave_event event
, u8
*val
)
386 return client
->slave_cb(client
, event
, val
);
389 static inline bool i2c_detect_slave_mode(struct device
*dev
) { return false; }
393 * struct i2c_board_info - template for device creation
394 * @type: chip type, to initialize i2c_client.name
395 * @flags: to initialize i2c_client.flags
396 * @addr: stored in i2c_client.addr
397 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
398 * @platform_data: stored in i2c_client.dev.platform_data
399 * @of_node: pointer to OpenFirmware device node
400 * @fwnode: device node supplied by the platform firmware
401 * @swnode: software node for the device
402 * @resources: resources associated with the device
403 * @num_resources: number of resources in the @resources array
404 * @irq: stored in i2c_client.irq
406 * I2C doesn't actually support hardware probing, although controllers and
407 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
408 * a device at a given address. Drivers commonly need more information than
409 * that, such as chip type, configuration, associated IRQ, and so on.
411 * i2c_board_info is used to build tables of information listing I2C devices
412 * that are present. This information is used to grow the driver model tree.
413 * For mainboards this is done statically using i2c_register_board_info();
414 * bus numbers identify adapters that aren't yet available. For add-on boards,
415 * i2c_new_client_device() does this dynamically with the adapter already known.
417 struct i2c_board_info
{
418 char type
[I2C_NAME_SIZE
];
419 unsigned short flags
;
421 const char *dev_name
;
423 struct device_node
*of_node
;
424 struct fwnode_handle
*fwnode
;
425 const struct software_node
*swnode
;
426 const struct resource
*resources
;
427 unsigned int num_resources
;
432 * I2C_BOARD_INFO - macro used to list an i2c device and its address
433 * @dev_type: identifies the device type
434 * @dev_addr: the device's address on the bus.
436 * This macro initializes essential fields of a struct i2c_board_info,
437 * declaring what has been provided on a particular board. Optional
438 * fields (such as associated irq, or device-specific platform_data)
439 * are provided using conventional syntax.
441 #define I2C_BOARD_INFO(dev_type, dev_addr) \
442 .type = dev_type, .addr = (dev_addr)
445 #if IS_ENABLED(CONFIG_I2C)
447 * Add-on boards should register/unregister their devices; e.g. a board
448 * with integrated I2C, a config eeprom, sensors, and a codec that's
449 * used in conjunction with the primary hardware.
452 i2c_new_client_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
454 /* If you don't know the exact address of an I2C device, use this variant
455 * instead, which can probe for device presence in a list of possible
456 * addresses. The "probe" callback function is optional. If it is provided,
457 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
458 * a default probing method is used.
461 i2c_new_scanned_device(struct i2c_adapter
*adap
,
462 struct i2c_board_info
*info
,
463 unsigned short const *addr_list
,
464 int (*probe
)(struct i2c_adapter
*adap
, unsigned short addr
));
466 /* Common custom probe functions */
467 int i2c_probe_func_quick_read(struct i2c_adapter
*adap
, unsigned short addr
);
470 i2c_new_dummy_device(struct i2c_adapter
*adapter
, u16 address
);
473 devm_i2c_new_dummy_device(struct device
*dev
, struct i2c_adapter
*adap
, u16 address
);
476 i2c_new_ancillary_device(struct i2c_client
*client
,
480 void i2c_unregister_device(struct i2c_client
*client
);
482 struct i2c_client
*i2c_verify_client(struct device
*dev
);
484 static inline struct i2c_client
*i2c_verify_client(struct device
*dev
)
490 /* Mainboard arch_initcall() code should register all its I2C devices.
491 * This is done at arch_initcall time, before declaring any i2c adapters.
492 * Modules for add-on boards must use other calls.
494 #ifdef CONFIG_I2C_BOARDINFO
496 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
500 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
505 #endif /* I2C_BOARDINFO */
508 * struct i2c_algorithm - represent I2C transfer method
509 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
510 * defined by the msgs array, with num messages available to transfer via
511 * the adapter specified by adap.
512 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
513 * so e.g. PMICs can be accessed very late before shutdown. Optional.
514 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
515 * is not present, then the bus layer will try and convert the SMBus calls
516 * into I2C transfers instead.
517 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
518 * so e.g. PMICs can be accessed very late before shutdown. Optional.
519 * @functionality: Return the flags that this algorithm/adapter pair supports
520 * from the ``I2C_FUNC_*`` flags.
521 * @reg_slave: Register given client to I2C slave mode of this adapter
522 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
524 * The following structs are for those who like to implement new bus drivers:
525 * i2c_algorithm is the interface to a class of hardware solutions which can
526 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
527 * to name two of the most common.
529 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
530 * type of error code that occurred during the transfer, as documented in the
531 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
533 struct i2c_algorithm
{
535 * If an adapter algorithm can't do I2C-level access, set master_xfer
536 * to NULL. If an adapter algorithm can do SMBus access, set
537 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
538 * using common I2C messages.
540 * master_xfer should return the number of messages successfully
541 * processed, or a negative value on error
543 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
545 int (*master_xfer_atomic
)(struct i2c_adapter
*adap
,
546 struct i2c_msg
*msgs
, int num
);
547 int (*smbus_xfer
)(struct i2c_adapter
*adap
, u16 addr
,
548 unsigned short flags
, char read_write
,
549 u8 command
, int size
, union i2c_smbus_data
*data
);
550 int (*smbus_xfer_atomic
)(struct i2c_adapter
*adap
, u16 addr
,
551 unsigned short flags
, char read_write
,
552 u8 command
, int size
, union i2c_smbus_data
*data
);
554 /* To determine what the adapter supports */
555 u32 (*functionality
)(struct i2c_adapter
*adap
);
557 #if IS_ENABLED(CONFIG_I2C_SLAVE)
558 int (*reg_slave
)(struct i2c_client
*client
);
559 int (*unreg_slave
)(struct i2c_client
*client
);
564 * struct i2c_lock_operations - represent I2C locking operations
565 * @lock_bus: Get exclusive access to an I2C bus segment
566 * @trylock_bus: Try to get exclusive access to an I2C bus segment
567 * @unlock_bus: Release exclusive access to an I2C bus segment
569 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
571 struct i2c_lock_operations
{
572 void (*lock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
573 int (*trylock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
574 void (*unlock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
578 * struct i2c_timings - I2C timing information
579 * @bus_freq_hz: the bus frequency in Hz
580 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
581 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
582 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
583 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
584 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
585 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
586 * digital filter can filter out
587 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
594 u32 scl_int_delay_ns
;
597 u32 digital_filter_width_ns
;
598 u32 analog_filter_cutoff_freq_hz
;
602 * struct i2c_bus_recovery_info - I2C bus recovery information
603 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
604 * i2c_generic_scl_recovery().
605 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
606 * recovery. Populated internally for generic GPIO recovery.
607 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
608 * Populated internally for generic GPIO recovery.
609 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
610 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
611 * GPIO, for generic GPIO recovery.
612 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
613 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
614 * for generic GPIO recovery.
615 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
616 * has a more complex internal logic than just reading SDA. Optional.
617 * @prepare_recovery: This will be called before starting recovery. Platform may
618 * configure padmux here for SDA/SCL line or something else they want.
619 * @unprepare_recovery: This will be called after completing recovery. Platform
620 * may configure padmux here for SDA/SCL line or something else they want.
621 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
622 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
623 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
625 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
626 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
627 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
628 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
629 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
630 * is called "gpio" or "recovery" and pinctrl is valid.
632 struct i2c_bus_recovery_info
{
633 int (*recover_bus
)(struct i2c_adapter
*adap
);
635 int (*get_scl
)(struct i2c_adapter
*adap
);
636 void (*set_scl
)(struct i2c_adapter
*adap
, int val
);
637 int (*get_sda
)(struct i2c_adapter
*adap
);
638 void (*set_sda
)(struct i2c_adapter
*adap
, int val
);
639 int (*get_bus_free
)(struct i2c_adapter
*adap
);
641 void (*prepare_recovery
)(struct i2c_adapter
*adap
);
642 void (*unprepare_recovery
)(struct i2c_adapter
*adap
);
645 struct gpio_desc
*scl_gpiod
;
646 struct gpio_desc
*sda_gpiod
;
647 struct pinctrl
*pinctrl
;
648 struct pinctrl_state
*pins_default
;
649 struct pinctrl_state
*pins_gpio
;
652 int i2c_recover_bus(struct i2c_adapter
*adap
);
654 /* Generic recovery routines */
655 int i2c_generic_scl_recovery(struct i2c_adapter
*adap
);
658 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
659 * @flags: see I2C_AQ_* for possible flags and read below
660 * @max_num_msgs: maximum number of messages per transfer
661 * @max_write_len: maximum length of a write message
662 * @max_read_len: maximum length of a read message
663 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
664 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
666 * Note about combined messages: Some I2C controllers can only send one message
667 * per transfer, plus something called combined message or write-then-read.
668 * This is (usually) a small write message followed by a read message and
669 * barely enough to access register based devices like EEPROMs. There is a flag
670 * to support this mode. It implies max_num_msg = 2 and does the length checks
671 * with max_comb_*_len because combined message mode usually has its own
672 * limitations. Because of HW implementations, some controllers can actually do
673 * write-then-anything or other variants. To support that, write-then-read has
674 * been broken out into smaller bits like write-first and read-second which can
675 * be combined as needed.
678 struct i2c_adapter_quirks
{
683 u16 max_comb_1st_msg_len
;
684 u16 max_comb_2nd_msg_len
;
687 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
688 #define I2C_AQ_COMB BIT(0)
689 /* first combined message must be write */
690 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
691 /* second combined message must be read */
692 #define I2C_AQ_COMB_READ_SECOND BIT(2)
693 /* both combined messages must have the same target address */
694 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
695 /* convenience macro for typical write-then read case */
696 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
697 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
698 /* clock stretching is not supported */
699 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
700 /* message cannot have length of 0 */
701 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
702 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
703 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
704 /* adapter cannot do repeated START */
705 #define I2C_AQ_NO_REP_START BIT(7)
708 * i2c_adapter is the structure used to identify a physical i2c bus along
709 * with the access algorithms necessary to access it.
712 struct module
*owner
;
713 unsigned int class; /* classes to allow probing for */
714 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
717 /* data fields that are valid for all devices */
718 const struct i2c_lock_operations
*lock_ops
;
719 struct rt_mutex bus_lock
;
720 struct rt_mutex mux_lock
;
722 int timeout
; /* in jiffies */
724 struct device dev
; /* the adapter device */
725 unsigned long locked_flags
; /* owned by the I2C core */
726 #define I2C_ALF_IS_SUSPENDED 0
727 #define I2C_ALF_SUSPEND_REPORTED 1
731 struct completion dev_released
;
733 struct mutex userspace_clients_lock
;
734 struct list_head userspace_clients
;
736 struct i2c_bus_recovery_info
*bus_recovery_info
;
737 const struct i2c_adapter_quirks
*quirks
;
739 struct irq_domain
*host_notify_domain
;
740 struct regulator
*bus_regulator
;
742 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
744 static inline void *i2c_get_adapdata(const struct i2c_adapter
*adap
)
746 return dev_get_drvdata(&adap
->dev
);
749 static inline void i2c_set_adapdata(struct i2c_adapter
*adap
, void *data
)
751 dev_set_drvdata(&adap
->dev
, data
);
754 static inline struct i2c_adapter
*
755 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
757 #if IS_ENABLED(CONFIG_I2C_MUX)
758 struct device
*parent
= adapter
->dev
.parent
;
760 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
761 return to_i2c_adapter(parent
);
767 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*dev
, void *data
));
769 /* Adapter locking functions, exported for shared pin cases */
770 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
771 #define I2C_LOCK_SEGMENT BIT(1)
774 * i2c_lock_bus - Get exclusive access to an I2C bus segment
775 * @adapter: Target I2C bus segment
776 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
777 * locks only this branch in the adapter tree
780 i2c_lock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
782 adapter
->lock_ops
->lock_bus(adapter
, flags
);
786 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
787 * @adapter: Target I2C bus segment
788 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
789 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
791 * Return: true if the I2C bus segment is locked, false otherwise
794 i2c_trylock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
796 return adapter
->lock_ops
->trylock_bus(adapter
, flags
);
800 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
801 * @adapter: Target I2C bus segment
802 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
803 * unlocks only this branch in the adapter tree
806 i2c_unlock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
808 adapter
->lock_ops
->unlock_bus(adapter
, flags
);
812 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
813 * @adap: Adapter to mark as suspended
815 * When using this helper to mark an adapter as suspended, the core will reject
816 * further transfers to this adapter. The usage of this helper is optional but
817 * recommended for devices having distinct handlers for system suspend and
818 * runtime suspend. More complex devices are free to implement custom solutions
819 * to reject transfers when suspended.
821 static inline void i2c_mark_adapter_suspended(struct i2c_adapter
*adap
)
823 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
824 set_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
825 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
829 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
830 * @adap: Adapter to mark as resumed
832 * When using this helper to mark an adapter as resumed, the core will allow
833 * further transfers to this adapter. See also further notes to
834 * @i2c_mark_adapter_suspended().
836 static inline void i2c_mark_adapter_resumed(struct i2c_adapter
*adap
)
838 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
839 clear_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
840 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
843 /* i2c adapter classes (bitmask) */
844 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
845 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
846 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
847 /* Warn users that the adapter doesn't support classes anymore */
848 #define I2C_CLASS_DEPRECATED (1<<8)
850 /* Internal numbers to terminate lists */
851 #define I2C_CLIENT_END 0xfffeU
853 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
854 #define I2C_ADDRS(addr, addrs...) \
855 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
858 /* ----- functions exported by i2c.o */
862 #if IS_ENABLED(CONFIG_I2C)
863 int i2c_add_adapter(struct i2c_adapter
*adap
);
864 int devm_i2c_add_adapter(struct device
*dev
, struct i2c_adapter
*adapter
);
865 void i2c_del_adapter(struct i2c_adapter
*adap
);
866 int i2c_add_numbered_adapter(struct i2c_adapter
*adap
);
868 int i2c_register_driver(struct module
*owner
, struct i2c_driver
*driver
);
869 void i2c_del_driver(struct i2c_driver
*driver
);
871 /* use a define to avoid include chaining to get THIS_MODULE */
872 #define i2c_add_driver(driver) \
873 i2c_register_driver(THIS_MODULE, driver)
875 static inline bool i2c_client_has_driver(struct i2c_client
*client
)
877 return !IS_ERR_OR_NULL(client
) && client
->dev
.driver
;
880 /* call the i2c_client->command() of all attached clients with
881 * the given arguments */
882 void i2c_clients_command(struct i2c_adapter
*adap
,
883 unsigned int cmd
, void *arg
);
885 struct i2c_adapter
*i2c_get_adapter(int nr
);
886 void i2c_put_adapter(struct i2c_adapter
*adap
);
887 unsigned int i2c_adapter_depth(struct i2c_adapter
*adapter
);
889 void i2c_parse_fw_timings(struct device
*dev
, struct i2c_timings
*t
, bool use_defaults
);
891 /* Return the functionality mask */
892 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
894 return adap
->algo
->functionality(adap
);
897 /* Return 1 if adapter supports everything we need, 0 if not. */
898 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
900 return (func
& i2c_get_functionality(adap
)) == func
;
904 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
906 * @quirks: quirk flags
908 * Return: true if the adapter has all the specified quirk flags, false if not
910 static inline bool i2c_check_quirks(struct i2c_adapter
*adap
, u64 quirks
)
914 return (adap
->quirks
->flags
& quirks
) == quirks
;
917 /* Return the adapter number for a specific adapter */
918 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
923 static inline u8
i2c_8bit_addr_from_msg(const struct i2c_msg
*msg
)
925 return (msg
->addr
<< 1) | (msg
->flags
& I2C_M_RD
? 1 : 0);
928 u8
*i2c_get_dma_safe_msg_buf(struct i2c_msg
*msg
, unsigned int threshold
);
929 void i2c_put_dma_safe_msg_buf(u8
*buf
, struct i2c_msg
*msg
, bool xferred
);
931 int i2c_handle_smbus_host_notify(struct i2c_adapter
*adap
, unsigned short addr
);
933 * module_i2c_driver() - Helper macro for registering a modular I2C driver
934 * @__i2c_driver: i2c_driver struct
936 * Helper macro for I2C drivers which do not do anything special in module
937 * init/exit. This eliminates a lot of boilerplate. Each module may only
938 * use this macro once, and calling it replaces module_init() and module_exit()
940 #define module_i2c_driver(__i2c_driver) \
941 module_driver(__i2c_driver, i2c_add_driver, \
945 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
946 * @__i2c_driver: i2c_driver struct
948 * Helper macro for I2C drivers which do not do anything special in their
949 * init. This eliminates a lot of boilerplate. Each driver may only
950 * use this macro once, and calling it replaces device_initcall().
952 #define builtin_i2c_driver(__i2c_driver) \
953 builtin_driver(__i2c_driver, i2c_add_driver)
957 #if IS_ENABLED(CONFIG_OF)
958 /* must call put_device() when done with returned i2c_client device */
959 struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
);
961 /* must call put_device() when done with returned i2c_adapter device */
962 struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
);
964 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
965 struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
);
967 const struct of_device_id
968 *i2c_of_match_device(const struct of_device_id
*matches
,
969 struct i2c_client
*client
);
971 int of_i2c_get_board_info(struct device
*dev
, struct device_node
*node
,
972 struct i2c_board_info
*info
);
976 static inline struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
)
981 static inline struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
)
986 static inline struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
)
991 static inline const struct of_device_id
992 *i2c_of_match_device(const struct of_device_id
*matches
,
993 struct i2c_client
*client
)
998 static inline int of_i2c_get_board_info(struct device
*dev
,
999 struct device_node
*node
,
1000 struct i2c_board_info
*info
)
1005 #endif /* CONFIG_OF */
1007 struct acpi_resource
;
1008 struct acpi_resource_i2c_serialbus
;
1010 #if IS_ENABLED(CONFIG_ACPI)
1011 bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
1012 struct acpi_resource_i2c_serialbus
**i2c
);
1013 int i2c_acpi_client_count(struct acpi_device
*adev
);
1014 u32
i2c_acpi_find_bus_speed(struct device
*dev
);
1015 struct i2c_client
*i2c_acpi_new_device(struct device
*dev
, int index
,
1016 struct i2c_board_info
*info
);
1017 struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
);
1019 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
1020 struct acpi_resource_i2c_serialbus
**i2c
)
1024 static inline int i2c_acpi_client_count(struct acpi_device
*adev
)
1028 static inline u32
i2c_acpi_find_bus_speed(struct device
*dev
)
1032 static inline struct i2c_client
*i2c_acpi_new_device(struct device
*dev
,
1033 int index
, struct i2c_board_info
*info
)
1035 return ERR_PTR(-ENODEV
);
1037 static inline struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
)
1041 #endif /* CONFIG_ACPI */
1043 #endif /* _LINUX_I2C_H */