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@the-dreams.de>
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);
43 struct property_entry;
45 #if IS_ENABLED(CONFIG_I2C)
47 * The master routines are the ones normally used to transmit data to devices
48 * on a bus (or read from them). Apart from two basic transfer functions to
49 * transmit one message at a time, a more complex version can be used to
50 * transmit an arbitrary number of messages without interruption.
51 * @count must be be less than 64k since msg.len is u16.
53 int i2c_transfer_buffer_flags(const struct i2c_client *client,
54 char *buf, int count, u16 flags);
57 * i2c_master_recv - issue a single I2C message in master receive mode
58 * @client: Handle to slave device
59 * @buf: Where to store data read from slave
60 * @count: How many bytes to read, must be less than 64k since msg.len is u16
62 * Returns negative errno, or else the number of bytes read.
64 static inline int i2c_master_recv(const struct i2c_client *client,
67 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
71 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
72 * using a DMA safe buffer
73 * @client: Handle to slave device
74 * @buf: Where to store data read from slave, must be safe to use with DMA
75 * @count: How many bytes to read, must be less than 64k since msg.len is u16
77 * Returns negative errno, or else the number of bytes read.
79 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
82 return i2c_transfer_buffer_flags(client, buf, count,
83 I2C_M_RD | I2C_M_DMA_SAFE);
87 * i2c_master_send - issue a single I2C message in master transmit mode
88 * @client: Handle to slave device
89 * @buf: Data that will be written to the slave
90 * @count: How many bytes to write, must be less than 64k since msg.len is u16
92 * Returns negative errno, or else the number of bytes written.
94 static inline int i2c_master_send(const struct i2c_client *client,
95 const char *buf, int count)
97 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
101 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
102 * using a DMA safe buffer
103 * @client: Handle to slave device
104 * @buf: Data that will be written to the slave, must be safe to use with DMA
105 * @count: How many bytes to write, must be less than 64k since msg.len is u16
107 * Returns negative errno, or else the number of bytes written.
109 static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
110 const char *buf, int count)
112 return i2c_transfer_buffer_flags(client, (char *)buf, count,
116 /* Transfer num messages.
118 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
119 /* Unlocked flavor */
120 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
122 /* This is the very generalized SMBus access routine. You probably do not
123 want to use this, though; one of the functions below may be much easier,
124 and probably just as fast.
125 Note that we use i2c_adapter here, because you do not need a specific
126 smbus adapter to call this function. */
127 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
128 unsigned short flags, char read_write, u8 command,
129 int protocol, union i2c_smbus_data *data);
131 /* Unlocked flavor */
132 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
133 unsigned short flags, char read_write, u8 command,
134 int protocol, union i2c_smbus_data *data);
136 /* Now follow the 'nice' access routines. These also document the calling
137 conventions of i2c_smbus_xfer. */
139 s32 i2c_smbus_read_byte(const struct i2c_client *client);
140 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
141 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
142 s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
143 u8 command, u8 value);
144 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
145 s32 i2c_smbus_write_word_data(const struct i2c_client *client,
146 u8 command, u16 value);
149 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
151 s32 value = i2c_smbus_read_word_data(client, command);
153 return (value < 0) ? value : swab16(value);
157 i2c_smbus_write_word_swapped(const struct i2c_client *client,
158 u8 command, u16 value)
160 return i2c_smbus_write_word_data(client, command, swab16(value));
163 /* Returns the number of read bytes */
164 s32 i2c_smbus_read_block_data(const struct i2c_client *client,
165 u8 command, u8 *values);
166 s32 i2c_smbus_write_block_data(const struct i2c_client *client,
167 u8 command, u8 length, const u8 *values);
168 /* Returns the number of read bytes */
169 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
170 u8 command, u8 length, u8 *values);
171 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
172 u8 command, u8 length, const u8 *values);
173 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
174 u8 command, u8 length,
176 int i2c_get_device_id(const struct i2c_client *client,
177 struct i2c_device_identity *id);
181 * struct i2c_device_identity - i2c client device identification
182 * @manufacturer_id: 0 - 4095, database maintained by NXP
183 * @part_id: 0 - 511, according to manufacturer
184 * @die_revision: 0 - 7, according to manufacturer
186 struct i2c_device_identity {
188 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
189 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
190 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
191 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
192 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
193 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
194 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
195 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
196 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
197 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
198 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
199 #define I2C_DEVICE_ID_FLIR 11
200 #define I2C_DEVICE_ID_O2MICRO 12
201 #define I2C_DEVICE_ID_ATMEL 13
202 #define I2C_DEVICE_ID_NONE 0xffff
207 enum i2c_alert_protocol {
208 I2C_PROTOCOL_SMBUS_ALERT,
209 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
213 * struct i2c_driver - represent an I2C device driver
214 * @class: What kind of i2c device we instantiate (for detect)
215 * @probe: Callback for device binding - soon to be deprecated
216 * @probe_new: New callback for device binding
217 * @remove: Callback for device unbinding
218 * @shutdown: Callback for device shutdown
219 * @alert: Alert callback, for example for the SMBus alert protocol
220 * @command: Callback for bus-wide signaling (optional)
221 * @driver: Device driver model driver
222 * @id_table: List of I2C devices supported by this driver
223 * @detect: Callback for device detection
224 * @address_list: The I2C addresses to probe (for detect)
225 * @clients: List of detected clients we created (for i2c-core use only)
226 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
228 * The driver.owner field should be set to the module owner of this driver.
229 * The driver.name field should be set to the name of this driver.
231 * For automatic device detection, both @detect and @address_list must
232 * be defined. @class should also be set, otherwise only devices forced
233 * with module parameters will be created. The detect function must
234 * fill at least the name field of the i2c_board_info structure it is
235 * handed upon successful detection, and possibly also the flags field.
237 * If @detect is missing, the driver will still work fine for enumerated
238 * devices. Detected devices simply won't be supported. This is expected
239 * for the many I2C/SMBus devices which can't be detected reliably, and
240 * the ones which can always be enumerated in practice.
242 * The i2c_client structure which is handed to the @detect callback is
243 * not a real i2c_client. It is initialized just enough so that you can
244 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
245 * else with it. In particular, calling dev_dbg and friends on it is
251 /* Standard driver model interfaces */
252 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
253 int (*remove)(struct i2c_client *client);
255 /* New driver model interface to aid the seamless removal of the
256 * current probe()'s, more commonly unused than used second parameter.
258 int (*probe_new)(struct i2c_client *client);
260 /* driver model interfaces that don't relate to enumeration */
261 void (*shutdown)(struct i2c_client *client);
263 /* Alert callback, for example for the SMBus alert protocol.
264 * The format and meaning of the data value depends on the protocol.
265 * For the SMBus alert protocol, there is a single bit of data passed
266 * as the alert response's low bit ("event flag").
267 * For the SMBus Host Notify protocol, the data corresponds to the
268 * 16-bit payload data reported by the slave device acting as master.
270 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
273 /* a ioctl like command that can be used to perform specific functions
276 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
278 struct device_driver driver;
279 const struct i2c_device_id *id_table;
281 /* Device detection callback for automatic device creation */
282 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
283 const unsigned short *address_list;
284 struct list_head clients;
286 bool disable_i2c_core_irq_mapping;
288 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
291 * struct i2c_client - represent an I2C slave device
292 * @flags: see I2C_CLIENT_* for possible flags
293 * @addr: Address used on the I2C bus connected to the parent adapter.
294 * @name: Indicates the type of the device, usually a chip name that's
295 * generic enough to hide second-sourcing and compatible revisions.
296 * @adapter: manages the bus segment hosting this I2C device
297 * @dev: Driver model device node for the slave.
298 * @init_irq: IRQ that was set at initialization
299 * @irq: indicates the IRQ generated by this device (if any)
300 * @detected: member of an i2c_driver.clients list or i2c-core's
301 * userspace_devices list
302 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
303 * calls it to pass on slave events to the slave driver.
305 * An i2c_client identifies a single device (i.e. chip) connected to an
306 * i2c bus. The behaviour exposed to Linux is defined by the driver
307 * managing the device.
310 unsigned short flags; /* div., see below */
311 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
312 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
313 /* Must equal I2C_M_TEN below */
314 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
315 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
316 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
317 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
318 /* Must match I2C_M_STOP|IGNORE_NAK */
320 unsigned short addr; /* chip address - NOTE: 7bit */
321 /* addresses are stored in the */
323 char name[I2C_NAME_SIZE];
324 struct i2c_adapter *adapter; /* the adapter we sit on */
325 struct device dev; /* the device structure */
326 int init_irq; /* irq set at initialization */
327 int irq; /* irq issued by device */
328 struct list_head detected;
329 #if IS_ENABLED(CONFIG_I2C_SLAVE)
330 i2c_slave_cb_t slave_cb; /* callback for slave mode */
333 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
335 struct i2c_client *i2c_verify_client(struct device *dev);
336 struct i2c_adapter *i2c_verify_adapter(struct device *dev);
337 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
338 const struct i2c_client *client);
340 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
342 struct device * const dev = container_of(kobj, struct device, kobj);
343 return to_i2c_client(dev);
346 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
348 return dev_get_drvdata(&dev->dev);
351 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
353 dev_set_drvdata(&dev->dev, data);
356 /* I2C slave support */
358 #if IS_ENABLED(CONFIG_I2C_SLAVE)
359 enum i2c_slave_event {
360 I2C_SLAVE_READ_REQUESTED,
361 I2C_SLAVE_WRITE_REQUESTED,
362 I2C_SLAVE_READ_PROCESSED,
363 I2C_SLAVE_WRITE_RECEIVED,
367 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
368 int i2c_slave_unregister(struct i2c_client *client);
369 bool i2c_detect_slave_mode(struct device *dev);
371 static inline int i2c_slave_event(struct i2c_client *client,
372 enum i2c_slave_event event, u8 *val)
374 return client->slave_cb(client, event, val);
377 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
381 * struct i2c_board_info - template for device creation
382 * @type: chip type, to initialize i2c_client.name
383 * @flags: to initialize i2c_client.flags
384 * @addr: stored in i2c_client.addr
385 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
386 * @platform_data: stored in i2c_client.dev.platform_data
387 * @of_node: pointer to OpenFirmware device node
388 * @fwnode: device node supplied by the platform firmware
389 * @properties: additional device properties for the device
390 * @resources: resources associated with the device
391 * @num_resources: number of resources in the @resources array
392 * @irq: stored in i2c_client.irq
394 * I2C doesn't actually support hardware probing, although controllers and
395 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
396 * a device at a given address. Drivers commonly need more information than
397 * that, such as chip type, configuration, associated IRQ, and so on.
399 * i2c_board_info is used to build tables of information listing I2C devices
400 * that are present. This information is used to grow the driver model tree.
401 * For mainboards this is done statically using i2c_register_board_info();
402 * bus numbers identify adapters that aren't yet available. For add-on boards,
403 * i2c_new_device() does this dynamically with the adapter already known.
405 struct i2c_board_info {
406 char type[I2C_NAME_SIZE];
407 unsigned short flags;
409 const char *dev_name;
411 struct device_node *of_node;
412 struct fwnode_handle *fwnode;
413 const struct property_entry *properties;
414 const struct resource *resources;
415 unsigned int num_resources;
420 * I2C_BOARD_INFO - macro used to list an i2c device and its address
421 * @dev_type: identifies the device type
422 * @dev_addr: the device's address on the bus.
424 * This macro initializes essential fields of a struct i2c_board_info,
425 * declaring what has been provided on a particular board. Optional
426 * fields (such as associated irq, or device-specific platform_data)
427 * are provided using conventional syntax.
429 #define I2C_BOARD_INFO(dev_type, dev_addr) \
430 .type = dev_type, .addr = (dev_addr)
433 #if IS_ENABLED(CONFIG_I2C)
434 /* Add-on boards should register/unregister their devices; e.g. a board
435 * with integrated I2C, a config eeprom, sensors, and a codec that's
436 * used in conjunction with the primary hardware.
439 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
442 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
444 /* If you don't know the exact address of an I2C device, use this variant
445 * instead, which can probe for device presence in a list of possible
446 * addresses. The "probe" callback function is optional. If it is provided,
447 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
448 * a default probing method is used.
451 i2c_new_scanned_device(struct i2c_adapter *adap,
452 struct i2c_board_info *info,
453 unsigned short const *addr_list,
454 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
457 i2c_new_probed_device(struct i2c_adapter *adap,
458 struct i2c_board_info *info,
459 unsigned short const *addr_list,
460 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
462 /* Common custom probe functions */
463 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
466 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
469 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
472 i2c_new_ancillary_device(struct i2c_client *client,
476 void i2c_unregister_device(struct i2c_client *client);
479 /* Mainboard arch_initcall() code should register all its I2C devices.
480 * This is done at arch_initcall time, before declaring any i2c adapters.
481 * Modules for add-on boards must use other calls.
483 #ifdef CONFIG_I2C_BOARDINFO
485 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
489 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
494 #endif /* I2C_BOARDINFO */
497 * struct i2c_algorithm - represent I2C transfer method
498 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
499 * defined by the msgs array, with num messages available to transfer via
500 * the adapter specified by adap.
501 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
502 * so e.g. PMICs can be accessed very late before shutdown. Optional.
503 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
504 * is not present, then the bus layer will try and convert the SMBus calls
505 * into I2C transfers instead.
506 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
507 * so e.g. PMICs can be accessed very late before shutdown. Optional.
508 * @functionality: Return the flags that this algorithm/adapter pair supports
509 * from the ``I2C_FUNC_*`` flags.
510 * @reg_slave: Register given client to I2C slave mode of this adapter
511 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
513 * The following structs are for those who like to implement new bus drivers:
514 * i2c_algorithm is the interface to a class of hardware solutions which can
515 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
516 * to name two of the most common.
518 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
519 * type of error code that occurred during the transfer, as documented in the
520 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
522 struct i2c_algorithm {
524 * If an adapter algorithm can't do I2C-level access, set master_xfer
525 * to NULL. If an adapter algorithm can do SMBus access, set
526 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
527 * using common I2C messages.
529 * master_xfer should return the number of messages successfully
530 * processed, or a negative value on error
532 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
534 int (*master_xfer_atomic)(struct i2c_adapter *adap,
535 struct i2c_msg *msgs, int num);
536 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
537 unsigned short flags, char read_write,
538 u8 command, int size, union i2c_smbus_data *data);
539 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
540 unsigned short flags, char read_write,
541 u8 command, int size, union i2c_smbus_data *data);
543 /* To determine what the adapter supports */
544 u32 (*functionality)(struct i2c_adapter *adap);
546 #if IS_ENABLED(CONFIG_I2C_SLAVE)
547 int (*reg_slave)(struct i2c_client *client);
548 int (*unreg_slave)(struct i2c_client *client);
553 * struct i2c_lock_operations - represent I2C locking operations
554 * @lock_bus: Get exclusive access to an I2C bus segment
555 * @trylock_bus: Try to get exclusive access to an I2C bus segment
556 * @unlock_bus: Release exclusive access to an I2C bus segment
558 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
560 struct i2c_lock_operations {
561 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
562 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
563 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
567 * struct i2c_timings - I2C timing information
568 * @bus_freq_hz: the bus frequency in Hz
569 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
570 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
571 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
572 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
573 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
574 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
575 * digital filter can filter out
576 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
583 u32 scl_int_delay_ns;
586 u32 digital_filter_width_ns;
587 u32 analog_filter_cutoff_freq_hz;
591 * struct i2c_bus_recovery_info - I2C bus recovery information
592 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
593 * i2c_generic_scl_recovery().
594 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
595 * recovery. Populated internally for generic GPIO recovery.
596 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
597 * Populated internally for generic GPIO recovery.
598 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
599 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
600 * GPIO, for generic GPIO recovery.
601 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
602 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
603 * for generic GPIO recovery.
604 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
605 * has a more complex internal logic than just reading SDA. Optional.
606 * @prepare_recovery: This will be called before starting recovery. Platform may
607 * configure padmux here for SDA/SCL line or something else they want.
608 * @unprepare_recovery: This will be called after completing recovery. Platform
609 * may configure padmux here for SDA/SCL line or something else they want.
610 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
611 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
613 struct i2c_bus_recovery_info {
614 int (*recover_bus)(struct i2c_adapter *adap);
616 int (*get_scl)(struct i2c_adapter *adap);
617 void (*set_scl)(struct i2c_adapter *adap, int val);
618 int (*get_sda)(struct i2c_adapter *adap);
619 void (*set_sda)(struct i2c_adapter *adap, int val);
620 int (*get_bus_free)(struct i2c_adapter *adap);
622 void (*prepare_recovery)(struct i2c_adapter *adap);
623 void (*unprepare_recovery)(struct i2c_adapter *adap);
626 struct gpio_desc *scl_gpiod;
627 struct gpio_desc *sda_gpiod;
630 int i2c_recover_bus(struct i2c_adapter *adap);
632 /* Generic recovery routines */
633 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
636 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
637 * @flags: see I2C_AQ_* for possible flags and read below
638 * @max_num_msgs: maximum number of messages per transfer
639 * @max_write_len: maximum length of a write message
640 * @max_read_len: maximum length of a read message
641 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
642 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
644 * Note about combined messages: Some I2C controllers can only send one message
645 * per transfer, plus something called combined message or write-then-read.
646 * This is (usually) a small write message followed by a read message and
647 * barely enough to access register based devices like EEPROMs. There is a flag
648 * to support this mode. It implies max_num_msg = 2 and does the length checks
649 * with max_comb_*_len because combined message mode usually has its own
650 * limitations. Because of HW implementations, some controllers can actually do
651 * write-then-anything or other variants. To support that, write-then-read has
652 * been broken out into smaller bits like write-first and read-second which can
653 * be combined as needed.
656 struct i2c_adapter_quirks {
661 u16 max_comb_1st_msg_len;
662 u16 max_comb_2nd_msg_len;
665 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
666 #define I2C_AQ_COMB BIT(0)
667 /* first combined message must be write */
668 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
669 /* second combined message must be read */
670 #define I2C_AQ_COMB_READ_SECOND BIT(2)
671 /* both combined messages must have the same target address */
672 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
673 /* convenience macro for typical write-then read case */
674 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
675 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
676 /* clock stretching is not supported */
677 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
678 /* message cannot have length of 0 */
679 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
680 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
681 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
684 * i2c_adapter is the structure used to identify a physical i2c bus along
685 * with the access algorithms necessary to access it.
688 struct module *owner;
689 unsigned int class; /* classes to allow probing for */
690 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
693 /* data fields that are valid for all devices */
694 const struct i2c_lock_operations *lock_ops;
695 struct rt_mutex bus_lock;
696 struct rt_mutex mux_lock;
698 int timeout; /* in jiffies */
700 struct device dev; /* the adapter device */
701 unsigned long locked_flags; /* owned by the I2C core */
702 #define I2C_ALF_IS_SUSPENDED 0
703 #define I2C_ALF_SUSPEND_REPORTED 1
707 struct completion dev_released;
709 struct mutex userspace_clients_lock;
710 struct list_head userspace_clients;
712 struct i2c_bus_recovery_info *bus_recovery_info;
713 const struct i2c_adapter_quirks *quirks;
715 struct irq_domain *host_notify_domain;
717 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
719 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
721 return dev_get_drvdata(&adap->dev);
724 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
726 dev_set_drvdata(&adap->dev, data);
729 static inline struct i2c_adapter *
730 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
732 #if IS_ENABLED(CONFIG_I2C_MUX)
733 struct device *parent = adapter->dev.parent;
735 if (parent != NULL && parent->type == &i2c_adapter_type)
736 return to_i2c_adapter(parent);
742 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
744 /* Adapter locking functions, exported for shared pin cases */
745 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
746 #define I2C_LOCK_SEGMENT BIT(1)
749 * i2c_lock_bus - Get exclusive access to an I2C bus segment
750 * @adapter: Target I2C bus segment
751 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
752 * locks only this branch in the adapter tree
755 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
757 adapter->lock_ops->lock_bus(adapter, flags);
761 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
762 * @adapter: Target I2C bus segment
763 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
764 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
766 * Return: true if the I2C bus segment is locked, false otherwise
769 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
771 return adapter->lock_ops->trylock_bus(adapter, flags);
775 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
776 * @adapter: Target I2C bus segment
777 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
778 * unlocks only this branch in the adapter tree
781 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
783 adapter->lock_ops->unlock_bus(adapter, flags);
787 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
788 * @adap: Adapter to mark as suspended
790 * When using this helper to mark an adapter as suspended, the core will reject
791 * further transfers to this adapter. The usage of this helper is optional but
792 * recommended for devices having distinct handlers for system suspend and
793 * runtime suspend. More complex devices are free to implement custom solutions
794 * to reject transfers when suspended.
796 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
798 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
799 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
800 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
804 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
805 * @adap: Adapter to mark as resumed
807 * When using this helper to mark an adapter as resumed, the core will allow
808 * further transfers to this adapter. See also further notes to
809 * @i2c_mark_adapter_suspended().
811 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
813 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
814 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
815 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
818 /* i2c adapter classes (bitmask) */
819 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
820 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
821 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
822 /* Warn users that the adapter doesn't support classes anymore */
823 #define I2C_CLASS_DEPRECATED (1<<8)
825 /* Internal numbers to terminate lists */
826 #define I2C_CLIENT_END 0xfffeU
828 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
829 #define I2C_ADDRS(addr, addrs...) \
830 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
833 /* ----- functions exported by i2c.o */
837 #if IS_ENABLED(CONFIG_I2C)
838 int i2c_add_adapter(struct i2c_adapter *adap);
839 void i2c_del_adapter(struct i2c_adapter *adap);
840 int i2c_add_numbered_adapter(struct i2c_adapter *adap);
842 int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
843 void i2c_del_driver(struct i2c_driver *driver);
845 /* use a define to avoid include chaining to get THIS_MODULE */
846 #define i2c_add_driver(driver) \
847 i2c_register_driver(THIS_MODULE, driver)
849 static inline bool i2c_client_has_driver(struct i2c_client *client)
851 return !IS_ERR_OR_NULL(client) && client->dev.driver;
854 /* call the i2c_client->command() of all attached clients with
855 * the given arguments */
856 void i2c_clients_command(struct i2c_adapter *adap,
857 unsigned int cmd, void *arg);
859 struct i2c_adapter *i2c_get_adapter(int nr);
860 void i2c_put_adapter(struct i2c_adapter *adap);
861 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
863 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
865 /* Return the functionality mask */
866 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
868 return adap->algo->functionality(adap);
871 /* Return 1 if adapter supports everything we need, 0 if not. */
872 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
874 return (func & i2c_get_functionality(adap)) == func;
878 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
880 * @quirks: quirk flags
882 * Return: true if the adapter has all the specified quirk flags, false if not
884 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
888 return (adap->quirks->flags & quirks) == quirks;
891 /* Return the adapter number for a specific adapter */
892 static inline int i2c_adapter_id(struct i2c_adapter *adap)
897 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
899 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
902 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
903 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
905 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
907 * module_i2c_driver() - Helper macro for registering a modular I2C driver
908 * @__i2c_driver: i2c_driver struct
910 * Helper macro for I2C drivers which do not do anything special in module
911 * init/exit. This eliminates a lot of boilerplate. Each module may only
912 * use this macro once, and calling it replaces module_init() and module_exit()
914 #define module_i2c_driver(__i2c_driver) \
915 module_driver(__i2c_driver, i2c_add_driver, \
919 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
920 * @__i2c_driver: i2c_driver struct
922 * Helper macro for I2C drivers which do not do anything special in their
923 * init. This eliminates a lot of boilerplate. Each driver may only
924 * use this macro once, and calling it replaces device_initcall().
926 #define builtin_i2c_driver(__i2c_driver) \
927 builtin_driver(__i2c_driver, i2c_add_driver)
931 #if IS_ENABLED(CONFIG_OF)
932 /* must call put_device() when done with returned i2c_client device */
933 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
935 /* must call put_device() when done with returned i2c_adapter device */
936 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
938 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
939 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
941 const struct of_device_id
942 *i2c_of_match_device(const struct of_device_id *matches,
943 struct i2c_client *client);
945 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
946 struct i2c_board_info *info);
950 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
955 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
960 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
965 static inline const struct of_device_id
966 *i2c_of_match_device(const struct of_device_id *matches,
967 struct i2c_client *client)
972 static inline int of_i2c_get_board_info(struct device *dev,
973 struct device_node *node,
974 struct i2c_board_info *info)
979 #endif /* CONFIG_OF */
981 struct acpi_resource;
982 struct acpi_resource_i2c_serialbus;
984 #if IS_ENABLED(CONFIG_ACPI)
985 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
986 struct acpi_resource_i2c_serialbus **i2c);
987 u32 i2c_acpi_find_bus_speed(struct device *dev);
988 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
989 struct i2c_board_info *info);
990 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
992 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
993 struct acpi_resource_i2c_serialbus **i2c)
997 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
1001 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
1002 int index, struct i2c_board_info *info)
1006 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1010 #endif /* CONFIG_ACPI */
1012 #endif /* _LINUX_I2C_H */