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)
55 * The master routines are the ones normally used to transmit data to devices
56 * on a bus (or read from them). Apart from two basic transfer functions to
57 * transmit one message at a time, a more complex version can be used to
58 * transmit an arbitrary number of messages without interruption.
59 * @count must be be less than 64k since msg.len is u16.
61 int i2c_transfer_buffer_flags(const struct i2c_client
*client
,
62 char *buf
, int count
, u16 flags
);
65 * i2c_master_recv - issue a single I2C message in master receive mode
66 * @client: Handle to slave device
67 * @buf: Where to store data read from slave
68 * @count: How many bytes to read, must be less than 64k since msg.len is u16
70 * Returns negative errno, or else the number of bytes read.
72 static inline int i2c_master_recv(const struct i2c_client
*client
,
75 return i2c_transfer_buffer_flags(client
, buf
, count
, I2C_M_RD
);
79 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
80 * using a DMA safe buffer
81 * @client: Handle to slave device
82 * @buf: Where to store data read from slave, must be safe to use with DMA
83 * @count: How many bytes to read, must be less than 64k since msg.len is u16
85 * Returns negative errno, or else the number of bytes read.
87 static inline int i2c_master_recv_dmasafe(const struct i2c_client
*client
,
90 return i2c_transfer_buffer_flags(client
, buf
, count
,
91 I2C_M_RD
| I2C_M_DMA_SAFE
);
95 * i2c_master_send - issue a single I2C message in master transmit mode
96 * @client: Handle to slave device
97 * @buf: Data that will be written to the slave
98 * @count: How many bytes to write, must be less than 64k since msg.len is u16
100 * Returns negative errno, or else the number of bytes written.
102 static inline int i2c_master_send(const struct i2c_client
*client
,
103 const char *buf
, int count
)
105 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
, 0);
109 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
110 * using a DMA safe buffer
111 * @client: Handle to slave device
112 * @buf: Data that will be written to the slave, must be safe to use with DMA
113 * @count: How many bytes to write, must be less than 64k since msg.len is u16
115 * Returns negative errno, or else the number of bytes written.
117 static inline int i2c_master_send_dmasafe(const struct i2c_client
*client
,
118 const char *buf
, int count
)
120 return i2c_transfer_buffer_flags(client
, (char *)buf
, count
,
124 /* Transfer num messages.
126 int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
127 /* Unlocked flavor */
128 int __i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
);
130 /* This is the very generalized SMBus access routine. You probably do not
131 want to use this, though; one of the functions below may be much easier,
132 and probably just as fast.
133 Note that we use i2c_adapter here, because you do not need a specific
134 smbus adapter to call this function. */
135 s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
136 unsigned short flags
, char read_write
, u8 command
,
137 int protocol
, union i2c_smbus_data
*data
);
139 /* Unlocked flavor */
140 s32
__i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
141 unsigned short flags
, char read_write
, u8 command
,
142 int protocol
, union i2c_smbus_data
*data
);
144 /* Now follow the 'nice' access routines. These also document the calling
145 conventions of i2c_smbus_xfer. */
147 s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
148 s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
149 s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
, u8 command
);
150 s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
151 u8 command
, u8 value
);
152 s32
i2c_smbus_read_word_data(const struct i2c_client
*client
, u8 command
);
153 s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
154 u8 command
, u16 value
);
157 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
159 s32 value
= i2c_smbus_read_word_data(client
, command
);
161 return (value
< 0) ? value
: swab16(value
);
165 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
166 u8 command
, u16 value
)
168 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
171 /* Returns the number of read bytes */
172 s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
173 u8 command
, u8
*values
);
174 s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
175 u8 command
, u8 length
, const u8
*values
);
176 /* Returns the number of read bytes */
177 s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
178 u8 command
, u8 length
, u8
*values
);
179 s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
180 u8 command
, u8 length
, const u8
*values
);
181 s32
i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client
*client
,
182 u8 command
, u8 length
,
184 int i2c_get_device_id(const struct i2c_client
*client
,
185 struct i2c_device_identity
*id
);
189 * struct i2c_device_identity - i2c client device identification
190 * @manufacturer_id: 0 - 4095, database maintained by NXP
191 * @part_id: 0 - 511, according to manufacturer
192 * @die_revision: 0 - 7, according to manufacturer
194 struct i2c_device_identity
{
196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
197 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
198 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
199 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
200 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
201 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
202 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
203 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
204 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
205 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
206 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
207 #define I2C_DEVICE_ID_FLIR 11
208 #define I2C_DEVICE_ID_O2MICRO 12
209 #define I2C_DEVICE_ID_ATMEL 13
210 #define I2C_DEVICE_ID_NONE 0xffff
215 enum i2c_alert_protocol
{
216 I2C_PROTOCOL_SMBUS_ALERT
,
217 I2C_PROTOCOL_SMBUS_HOST_NOTIFY
,
221 * struct i2c_driver - represent an I2C device driver
222 * @class: What kind of i2c device we instantiate (for detect)
223 * @probe: Callback for device binding - soon to be deprecated
224 * @probe_new: New callback for device binding
225 * @remove: Callback for device unbinding
226 * @shutdown: Callback for device shutdown
227 * @alert: Alert callback, for example for the SMBus alert protocol
228 * @command: Callback for bus-wide signaling (optional)
229 * @driver: Device driver model driver
230 * @id_table: List of I2C devices supported by this driver
231 * @detect: Callback for device detection
232 * @address_list: The I2C addresses to probe (for detect)
233 * @clients: List of detected clients we created (for i2c-core use only)
234 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
236 * The driver.owner field should be set to the module owner of this driver.
237 * The driver.name field should be set to the name of this driver.
239 * For automatic device detection, both @detect and @address_list must
240 * be defined. @class should also be set, otherwise only devices forced
241 * with module parameters will be created. The detect function must
242 * fill at least the name field of the i2c_board_info structure it is
243 * handed upon successful detection, and possibly also the flags field.
245 * If @detect is missing, the driver will still work fine for enumerated
246 * devices. Detected devices simply won't be supported. This is expected
247 * for the many I2C/SMBus devices which can't be detected reliably, and
248 * the ones which can always be enumerated in practice.
250 * The i2c_client structure which is handed to the @detect callback is
251 * not a real i2c_client. It is initialized just enough so that you can
252 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
253 * else with it. In particular, calling dev_dbg and friends on it is
259 /* Standard driver model interfaces */
260 int (*probe
)(struct i2c_client
*client
, const struct i2c_device_id
*id
);
261 int (*remove
)(struct i2c_client
*client
);
263 /* New driver model interface to aid the seamless removal of the
264 * current probe()'s, more commonly unused than used second parameter.
266 int (*probe_new
)(struct i2c_client
*client
);
268 /* driver model interfaces that don't relate to enumeration */
269 void (*shutdown
)(struct i2c_client
*client
);
271 /* Alert callback, for example for the SMBus alert protocol.
272 * The format and meaning of the data value depends on the protocol.
273 * For the SMBus alert protocol, there is a single bit of data passed
274 * as the alert response's low bit ("event flag").
275 * For the SMBus Host Notify protocol, the data corresponds to the
276 * 16-bit payload data reported by the slave device acting as master.
278 void (*alert
)(struct i2c_client
*client
, enum i2c_alert_protocol protocol
,
281 /* a ioctl like command that can be used to perform specific functions
284 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
286 struct device_driver driver
;
287 const struct i2c_device_id
*id_table
;
289 /* Device detection callback for automatic device creation */
290 int (*detect
)(struct i2c_client
*client
, struct i2c_board_info
*info
);
291 const unsigned short *address_list
;
292 struct list_head clients
;
294 bool disable_i2c_core_irq_mapping
;
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.
313 * An i2c_client identifies a single device (i.e. chip) connected to an
314 * i2c bus. The behaviour exposed to Linux is defined by the driver
315 * managing the device.
318 unsigned short flags
; /* div., see below */
319 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
320 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
321 /* Must equal I2C_M_TEN below */
322 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
323 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
324 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
325 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
326 /* Must match I2C_M_STOP|IGNORE_NAK */
328 unsigned short addr
; /* chip address - NOTE: 7bit */
329 /* addresses are stored in the */
331 char name
[I2C_NAME_SIZE
];
332 struct i2c_adapter
*adapter
; /* the adapter we sit on */
333 struct device dev
; /* the device structure */
334 int init_irq
; /* irq set at initialization */
335 int irq
; /* irq issued by device */
336 struct list_head detected
;
337 #if IS_ENABLED(CONFIG_I2C_SLAVE)
338 i2c_slave_cb_t slave_cb
; /* callback for slave mode */
341 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
343 struct i2c_client
*i2c_verify_client(struct device
*dev
);
344 struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
345 const struct i2c_device_id
*i2c_match_id(const struct i2c_device_id
*id
,
346 const struct i2c_client
*client
);
348 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
350 struct device
* const dev
= container_of(kobj
, struct device
, kobj
);
351 return to_i2c_client(dev
);
354 static inline void *i2c_get_clientdata(const struct i2c_client
*dev
)
356 return dev_get_drvdata(&dev
->dev
);
359 static inline void i2c_set_clientdata(struct i2c_client
*dev
, void *data
)
361 dev_set_drvdata(&dev
->dev
, data
);
364 /* I2C slave support */
366 #if IS_ENABLED(CONFIG_I2C_SLAVE)
367 enum i2c_slave_event
{
368 I2C_SLAVE_READ_REQUESTED
,
369 I2C_SLAVE_WRITE_REQUESTED
,
370 I2C_SLAVE_READ_PROCESSED
,
371 I2C_SLAVE_WRITE_RECEIVED
,
375 int i2c_slave_register(struct i2c_client
*client
, i2c_slave_cb_t slave_cb
);
376 int i2c_slave_unregister(struct i2c_client
*client
);
377 bool i2c_detect_slave_mode(struct device
*dev
);
379 static inline int i2c_slave_event(struct i2c_client
*client
,
380 enum i2c_slave_event event
, u8
*val
)
382 return client
->slave_cb(client
, event
, val
);
385 static inline bool i2c_detect_slave_mode(struct device
*dev
) { return false; }
389 * struct i2c_board_info - template for device creation
390 * @type: chip type, to initialize i2c_client.name
391 * @flags: to initialize i2c_client.flags
392 * @addr: stored in i2c_client.addr
393 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
394 * @platform_data: stored in i2c_client.dev.platform_data
395 * @of_node: pointer to OpenFirmware device node
396 * @fwnode: device node supplied by the platform firmware
397 * @properties: additional device properties for the device
398 * @resources: resources associated with the device
399 * @num_resources: number of resources in the @resources array
400 * @irq: stored in i2c_client.irq
402 * I2C doesn't actually support hardware probing, although controllers and
403 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
404 * a device at a given address. Drivers commonly need more information than
405 * that, such as chip type, configuration, associated IRQ, and so on.
407 * i2c_board_info is used to build tables of information listing I2C devices
408 * that are present. This information is used to grow the driver model tree.
409 * For mainboards this is done statically using i2c_register_board_info();
410 * bus numbers identify adapters that aren't yet available. For add-on boards,
411 * i2c_new_device() does this dynamically with the adapter already known.
413 struct i2c_board_info
{
414 char type
[I2C_NAME_SIZE
];
415 unsigned short flags
;
417 const char *dev_name
;
419 struct device_node
*of_node
;
420 struct fwnode_handle
*fwnode
;
421 const struct property_entry
*properties
;
422 const struct resource
*resources
;
423 unsigned int num_resources
;
428 * I2C_BOARD_INFO - macro used to list an i2c device and its address
429 * @dev_type: identifies the device type
430 * @dev_addr: the device's address on the bus.
432 * This macro initializes essential fields of a struct i2c_board_info,
433 * declaring what has been provided on a particular board. Optional
434 * fields (such as associated irq, or device-specific platform_data)
435 * are provided using conventional syntax.
437 #define I2C_BOARD_INFO(dev_type, dev_addr) \
438 .type = dev_type, .addr = (dev_addr)
441 #if IS_ENABLED(CONFIG_I2C)
442 /* Add-on boards should register/unregister their devices; e.g. a board
443 * with integrated I2C, a config eeprom, sensors, and a codec that's
444 * used in conjunction with the primary hardware.
447 i2c_new_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
450 i2c_new_client_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
452 /* If you don't know the exact address of an I2C device, use this variant
453 * instead, which can probe for device presence in a list of possible
454 * addresses. The "probe" callback function is optional. If it is provided,
455 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
456 * a default probing method is used.
459 i2c_new_scanned_device(struct i2c_adapter
*adap
,
460 struct i2c_board_info
*info
,
461 unsigned short const *addr_list
,
462 int (*probe
)(struct i2c_adapter
*adap
, unsigned short addr
));
464 /* Common custom probe functions */
465 int i2c_probe_func_quick_read(struct i2c_adapter
*adap
, unsigned short addr
);
468 i2c_new_dummy_device(struct i2c_adapter
*adapter
, u16 address
);
471 devm_i2c_new_dummy_device(struct device
*dev
, struct i2c_adapter
*adap
, u16 address
);
474 i2c_new_ancillary_device(struct i2c_client
*client
,
478 void i2c_unregister_device(struct i2c_client
*client
);
481 /* Mainboard arch_initcall() code should register all its I2C devices.
482 * This is done at arch_initcall time, before declaring any i2c adapters.
483 * Modules for add-on boards must use other calls.
485 #ifdef CONFIG_I2C_BOARDINFO
487 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
491 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
496 #endif /* I2C_BOARDINFO */
499 * struct i2c_algorithm - represent I2C transfer method
500 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
501 * defined by the msgs array, with num messages available to transfer via
502 * the adapter specified by adap.
503 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
504 * so e.g. PMICs can be accessed very late before shutdown. Optional.
505 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
506 * is not present, then the bus layer will try and convert the SMBus calls
507 * into I2C transfers instead.
508 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
509 * so e.g. PMICs can be accessed very late before shutdown. Optional.
510 * @functionality: Return the flags that this algorithm/adapter pair supports
511 * from the ``I2C_FUNC_*`` flags.
512 * @reg_slave: Register given client to I2C slave mode of this adapter
513 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
515 * The following structs are for those who like to implement new bus drivers:
516 * i2c_algorithm is the interface to a class of hardware solutions which can
517 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
518 * to name two of the most common.
520 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
521 * type of error code that occurred during the transfer, as documented in the
522 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
524 struct i2c_algorithm
{
526 * If an adapter algorithm can't do I2C-level access, set master_xfer
527 * to NULL. If an adapter algorithm can do SMBus access, set
528 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
529 * using common I2C messages.
531 * master_xfer should return the number of messages successfully
532 * processed, or a negative value on error
534 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
536 int (*master_xfer_atomic
)(struct i2c_adapter
*adap
,
537 struct i2c_msg
*msgs
, int num
);
538 int (*smbus_xfer
)(struct i2c_adapter
*adap
, u16 addr
,
539 unsigned short flags
, char read_write
,
540 u8 command
, int size
, union i2c_smbus_data
*data
);
541 int (*smbus_xfer_atomic
)(struct i2c_adapter
*adap
, u16 addr
,
542 unsigned short flags
, char read_write
,
543 u8 command
, int size
, union i2c_smbus_data
*data
);
545 /* To determine what the adapter supports */
546 u32 (*functionality
)(struct i2c_adapter
*adap
);
548 #if IS_ENABLED(CONFIG_I2C_SLAVE)
549 int (*reg_slave
)(struct i2c_client
*client
);
550 int (*unreg_slave
)(struct i2c_client
*client
);
555 * struct i2c_lock_operations - represent I2C locking operations
556 * @lock_bus: Get exclusive access to an I2C bus segment
557 * @trylock_bus: Try to get exclusive access to an I2C bus segment
558 * @unlock_bus: Release exclusive access to an I2C bus segment
560 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
562 struct i2c_lock_operations
{
563 void (*lock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
564 int (*trylock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
565 void (*unlock_bus
)(struct i2c_adapter
*adapter
, unsigned int flags
);
569 * struct i2c_timings - I2C timing information
570 * @bus_freq_hz: the bus frequency in Hz
571 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
572 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
573 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
574 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
575 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
576 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
577 * digital filter can filter out
578 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
585 u32 scl_int_delay_ns
;
588 u32 digital_filter_width_ns
;
589 u32 analog_filter_cutoff_freq_hz
;
593 * struct i2c_bus_recovery_info - I2C bus recovery information
594 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
595 * i2c_generic_scl_recovery().
596 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
597 * recovery. Populated internally for generic GPIO recovery.
598 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
599 * Populated internally for generic GPIO recovery.
600 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
601 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
602 * GPIO, for generic GPIO recovery.
603 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
604 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
605 * for generic GPIO recovery.
606 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
607 * has a more complex internal logic than just reading SDA. Optional.
608 * @prepare_recovery: This will be called before starting recovery. Platform may
609 * configure padmux here for SDA/SCL line or something else they want.
610 * @unprepare_recovery: This will be called after completing recovery. Platform
611 * may configure padmux here for SDA/SCL line or something else they want.
612 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
613 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
615 struct i2c_bus_recovery_info
{
616 int (*recover_bus
)(struct i2c_adapter
*adap
);
618 int (*get_scl
)(struct i2c_adapter
*adap
);
619 void (*set_scl
)(struct i2c_adapter
*adap
, int val
);
620 int (*get_sda
)(struct i2c_adapter
*adap
);
621 void (*set_sda
)(struct i2c_adapter
*adap
, int val
);
622 int (*get_bus_free
)(struct i2c_adapter
*adap
);
624 void (*prepare_recovery
)(struct i2c_adapter
*adap
);
625 void (*unprepare_recovery
)(struct i2c_adapter
*adap
);
628 struct gpio_desc
*scl_gpiod
;
629 struct gpio_desc
*sda_gpiod
;
632 int i2c_recover_bus(struct i2c_adapter
*adap
);
634 /* Generic recovery routines */
635 int i2c_generic_scl_recovery(struct i2c_adapter
*adap
);
638 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
639 * @flags: see I2C_AQ_* for possible flags and read below
640 * @max_num_msgs: maximum number of messages per transfer
641 * @max_write_len: maximum length of a write message
642 * @max_read_len: maximum length of a read message
643 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
644 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
646 * Note about combined messages: Some I2C controllers can only send one message
647 * per transfer, plus something called combined message or write-then-read.
648 * This is (usually) a small write message followed by a read message and
649 * barely enough to access register based devices like EEPROMs. There is a flag
650 * to support this mode. It implies max_num_msg = 2 and does the length checks
651 * with max_comb_*_len because combined message mode usually has its own
652 * limitations. Because of HW implementations, some controllers can actually do
653 * write-then-anything or other variants. To support that, write-then-read has
654 * been broken out into smaller bits like write-first and read-second which can
655 * be combined as needed.
658 struct i2c_adapter_quirks
{
663 u16 max_comb_1st_msg_len
;
664 u16 max_comb_2nd_msg_len
;
667 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
668 #define I2C_AQ_COMB BIT(0)
669 /* first combined message must be write */
670 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
671 /* second combined message must be read */
672 #define I2C_AQ_COMB_READ_SECOND BIT(2)
673 /* both combined messages must have the same target address */
674 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
675 /* convenience macro for typical write-then read case */
676 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
677 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
678 /* clock stretching is not supported */
679 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
680 /* message cannot have length of 0 */
681 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
682 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
683 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
686 * i2c_adapter is the structure used to identify a physical i2c bus along
687 * with the access algorithms necessary to access it.
690 struct module
*owner
;
691 unsigned int class; /* classes to allow probing for */
692 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
695 /* data fields that are valid for all devices */
696 const struct i2c_lock_operations
*lock_ops
;
697 struct rt_mutex bus_lock
;
698 struct rt_mutex mux_lock
;
700 int timeout
; /* in jiffies */
702 struct device dev
; /* the adapter device */
703 unsigned long locked_flags
; /* owned by the I2C core */
704 #define I2C_ALF_IS_SUSPENDED 0
705 #define I2C_ALF_SUSPEND_REPORTED 1
709 struct completion dev_released
;
711 struct mutex userspace_clients_lock
;
712 struct list_head userspace_clients
;
714 struct i2c_bus_recovery_info
*bus_recovery_info
;
715 const struct i2c_adapter_quirks
*quirks
;
717 struct irq_domain
*host_notify_domain
;
719 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
721 static inline void *i2c_get_adapdata(const struct i2c_adapter
*adap
)
723 return dev_get_drvdata(&adap
->dev
);
726 static inline void i2c_set_adapdata(struct i2c_adapter
*adap
, void *data
)
728 dev_set_drvdata(&adap
->dev
, data
);
731 static inline struct i2c_adapter
*
732 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
734 #if IS_ENABLED(CONFIG_I2C_MUX)
735 struct device
*parent
= adapter
->dev
.parent
;
737 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
738 return to_i2c_adapter(parent
);
744 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*dev
, void *data
));
746 /* Adapter locking functions, exported for shared pin cases */
747 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
748 #define I2C_LOCK_SEGMENT BIT(1)
751 * i2c_lock_bus - Get exclusive access to an I2C bus segment
752 * @adapter: Target I2C bus segment
753 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
754 * locks only this branch in the adapter tree
757 i2c_lock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
759 adapter
->lock_ops
->lock_bus(adapter
, flags
);
763 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
764 * @adapter: Target I2C bus segment
765 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
766 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
768 * Return: true if the I2C bus segment is locked, false otherwise
771 i2c_trylock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
773 return adapter
->lock_ops
->trylock_bus(adapter
, flags
);
777 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
778 * @adapter: Target I2C bus segment
779 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
780 * unlocks only this branch in the adapter tree
783 i2c_unlock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
785 adapter
->lock_ops
->unlock_bus(adapter
, flags
);
789 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
790 * @adap: Adapter to mark as suspended
792 * When using this helper to mark an adapter as suspended, the core will reject
793 * further transfers to this adapter. The usage of this helper is optional but
794 * recommended for devices having distinct handlers for system suspend and
795 * runtime suspend. More complex devices are free to implement custom solutions
796 * to reject transfers when suspended.
798 static inline void i2c_mark_adapter_suspended(struct i2c_adapter
*adap
)
800 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
801 set_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
802 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
806 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
807 * @adap: Adapter to mark as resumed
809 * When using this helper to mark an adapter as resumed, the core will allow
810 * further transfers to this adapter. See also further notes to
811 * @i2c_mark_adapter_suspended().
813 static inline void i2c_mark_adapter_resumed(struct i2c_adapter
*adap
)
815 i2c_lock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
816 clear_bit(I2C_ALF_IS_SUSPENDED
, &adap
->locked_flags
);
817 i2c_unlock_bus(adap
, I2C_LOCK_ROOT_ADAPTER
);
820 /* i2c adapter classes (bitmask) */
821 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
822 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
823 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
824 /* Warn users that the adapter doesn't support classes anymore */
825 #define I2C_CLASS_DEPRECATED (1<<8)
827 /* Internal numbers to terminate lists */
828 #define I2C_CLIENT_END 0xfffeU
830 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
831 #define I2C_ADDRS(addr, addrs...) \
832 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
835 /* ----- functions exported by i2c.o */
839 #if IS_ENABLED(CONFIG_I2C)
840 int i2c_add_adapter(struct i2c_adapter
*adap
);
841 void i2c_del_adapter(struct i2c_adapter
*adap
);
842 int i2c_add_numbered_adapter(struct i2c_adapter
*adap
);
844 int i2c_register_driver(struct module
*owner
, struct i2c_driver
*driver
);
845 void i2c_del_driver(struct i2c_driver
*driver
);
847 /* use a define to avoid include chaining to get THIS_MODULE */
848 #define i2c_add_driver(driver) \
849 i2c_register_driver(THIS_MODULE, driver)
851 static inline bool i2c_client_has_driver(struct i2c_client
*client
)
853 return !IS_ERR_OR_NULL(client
) && client
->dev
.driver
;
856 /* call the i2c_client->command() of all attached clients with
857 * the given arguments */
858 void i2c_clients_command(struct i2c_adapter
*adap
,
859 unsigned int cmd
, void *arg
);
861 struct i2c_adapter
*i2c_get_adapter(int nr
);
862 void i2c_put_adapter(struct i2c_adapter
*adap
);
863 unsigned int i2c_adapter_depth(struct i2c_adapter
*adapter
);
865 void i2c_parse_fw_timings(struct device
*dev
, struct i2c_timings
*t
, bool use_defaults
);
867 /* Return the functionality mask */
868 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
870 return adap
->algo
->functionality(adap
);
873 /* Return 1 if adapter supports everything we need, 0 if not. */
874 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
876 return (func
& i2c_get_functionality(adap
)) == func
;
880 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
882 * @quirks: quirk flags
884 * Return: true if the adapter has all the specified quirk flags, false if not
886 static inline bool i2c_check_quirks(struct i2c_adapter
*adap
, u64 quirks
)
890 return (adap
->quirks
->flags
& quirks
) == quirks
;
893 /* Return the adapter number for a specific adapter */
894 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
899 static inline u8
i2c_8bit_addr_from_msg(const struct i2c_msg
*msg
)
901 return (msg
->addr
<< 1) | (msg
->flags
& I2C_M_RD
? 1 : 0);
904 u8
*i2c_get_dma_safe_msg_buf(struct i2c_msg
*msg
, unsigned int threshold
);
905 void i2c_put_dma_safe_msg_buf(u8
*buf
, struct i2c_msg
*msg
, bool xferred
);
907 int i2c_handle_smbus_host_notify(struct i2c_adapter
*adap
, unsigned short addr
);
909 * module_i2c_driver() - Helper macro for registering a modular I2C driver
910 * @__i2c_driver: i2c_driver struct
912 * Helper macro for I2C drivers which do not do anything special in module
913 * init/exit. This eliminates a lot of boilerplate. Each module may only
914 * use this macro once, and calling it replaces module_init() and module_exit()
916 #define module_i2c_driver(__i2c_driver) \
917 module_driver(__i2c_driver, i2c_add_driver, \
921 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
922 * @__i2c_driver: i2c_driver struct
924 * Helper macro for I2C drivers which do not do anything special in their
925 * init. This eliminates a lot of boilerplate. Each driver may only
926 * use this macro once, and calling it replaces device_initcall().
928 #define builtin_i2c_driver(__i2c_driver) \
929 builtin_driver(__i2c_driver, i2c_add_driver)
933 #if IS_ENABLED(CONFIG_OF)
934 /* must call put_device() when done with returned i2c_client device */
935 struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
);
937 /* must call put_device() when done with returned i2c_adapter device */
938 struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
);
940 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
941 struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
);
943 const struct of_device_id
944 *i2c_of_match_device(const struct of_device_id
*matches
,
945 struct i2c_client
*client
);
947 int of_i2c_get_board_info(struct device
*dev
, struct device_node
*node
,
948 struct i2c_board_info
*info
);
952 static inline struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
)
957 static inline struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
)
962 static inline struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
)
967 static inline const struct of_device_id
968 *i2c_of_match_device(const struct of_device_id
*matches
,
969 struct i2c_client
*client
)
974 static inline int of_i2c_get_board_info(struct device
*dev
,
975 struct device_node
*node
,
976 struct i2c_board_info
*info
)
981 #endif /* CONFIG_OF */
983 struct acpi_resource
;
984 struct acpi_resource_i2c_serialbus
;
986 #if IS_ENABLED(CONFIG_ACPI)
987 bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
988 struct acpi_resource_i2c_serialbus
**i2c
);
989 u32
i2c_acpi_find_bus_speed(struct device
*dev
);
990 struct i2c_client
*i2c_acpi_new_device(struct device
*dev
, int index
,
991 struct i2c_board_info
*info
);
992 struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
);
994 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource
*ares
,
995 struct acpi_resource_i2c_serialbus
**i2c
)
999 static inline u32
i2c_acpi_find_bus_speed(struct device
*dev
)
1003 static inline struct i2c_client
*i2c_acpi_new_device(struct device
*dev
,
1004 int index
, struct i2c_board_info
*info
)
1008 static inline struct i2c_adapter
*i2c_acpi_find_adapter_by_handle(acpi_handle handle
)
1012 #endif /* CONFIG_ACPI */
1014 #endif /* _LINUX_I2C_H */