1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* ------------------------------------------------------------------------- */
4 /* i2c.h - definitions for the i2c-bus interface */
6 /* ------------------------------------------------------------------------- */
7 /* Copyright (C) 1995-2000 Simon G. Vogl
10 /* ------------------------------------------------------------------------- */
12 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
13 Frodo Looijaard <frodol@dds.nl> */
17 #include <linux/acpi.h> /* for acpi_handle */
18 #include <linux/mod_devicetable.h>
19 #include <linux/device.h> /* for struct device */
20 #include <linux/sched.h> /* for completion */
21 #include <linux/mutex.h>
22 #include <linux/rtmutex.h>
23 #include <linux/irqdomain.h> /* for Host Notify IRQ */
24 #include <linux/of.h> /* for struct device_node */
25 #include <linux/swab.h> /* for swab16 */
26 #include <uapi/linux/i2c.h>
28 extern struct bus_type i2c_bus_type;
29 extern struct device_type i2c_adapter_type;
30 extern struct device_type i2c_client_type;
32 /* --- General options ------------------------------------------------ */
39 struct i2c_device_identity;
41 struct i2c_board_info;
43 typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
44 enum i2c_slave_event event, u8 *val);
47 struct property_entry;
49 #if IS_ENABLED(CONFIG_I2C)
51 * The master routines are the ones normally used to transmit data to devices
52 * on a bus (or read from them). Apart from two basic transfer functions to
53 * transmit one message at a time, a more complex version can be used to
54 * transmit an arbitrary number of messages without interruption.
55 * @count must be be less than 64k since msg.len is u16.
57 extern int i2c_transfer_buffer_flags(const struct i2c_client *client,
58 char *buf, int count, u16 flags);
61 * i2c_master_recv - issue a single I2C message in master receive mode
62 * @client: Handle to slave device
63 * @buf: Where to store data read from slave
64 * @count: How many bytes to read, must be less than 64k since msg.len is u16
66 * Returns negative errno, or else the number of bytes read.
68 static inline int i2c_master_recv(const struct i2c_client *client,
71 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
75 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
76 * using a DMA safe buffer
77 * @client: Handle to slave device
78 * @buf: Where to store data read from slave, must be safe to use with DMA
79 * @count: How many bytes to read, must be less than 64k since msg.len is u16
81 * Returns negative errno, or else the number of bytes read.
83 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
86 return i2c_transfer_buffer_flags(client, buf, count,
87 I2C_M_RD | I2C_M_DMA_SAFE);
91 * i2c_master_send - issue a single I2C message in master transmit mode
92 * @client: Handle to slave device
93 * @buf: Data that will be written to the slave
94 * @count: How many bytes to write, must be less than 64k since msg.len is u16
96 * Returns negative errno, or else the number of bytes written.
98 static inline int i2c_master_send(const struct i2c_client *client,
99 const char *buf, int count)
101 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
105 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
106 * using a DMA safe buffer
107 * @client: Handle to slave device
108 * @buf: Data that will be written to the slave, must be safe to use with DMA
109 * @count: How many bytes to write, must be less than 64k since msg.len is u16
111 * Returns negative errno, or else the number of bytes written.
113 static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
114 const char *buf, int count)
116 return i2c_transfer_buffer_flags(client, (char *)buf, count,
120 /* Transfer num messages.
122 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
124 /* Unlocked flavor */
125 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
128 /* This is the very generalized SMBus access routine. You probably do not
129 want to use this, though; one of the functions below may be much easier,
130 and probably just as fast.
131 Note that we use i2c_adapter here, because you do not need a specific
132 smbus adapter to call this function. */
133 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
134 unsigned short flags, char read_write, u8 command,
135 int protocol, union i2c_smbus_data *data);
137 /* Unlocked flavor */
138 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
139 unsigned short flags, char read_write, u8 command,
140 int protocol, union i2c_smbus_data *data);
142 /* Now follow the 'nice' access routines. These also document the calling
143 conventions of i2c_smbus_xfer. */
145 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
146 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
147 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
149 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
150 u8 command, u8 value);
151 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
153 extern 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 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
173 u8 command, u8 *values);
174 extern 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 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
178 u8 command, u8 length, u8 *values);
179 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
180 u8 command, u8 length,
183 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
184 u8 command, u8 length, u8 *values);
185 int i2c_get_device_id(const struct i2c_client *client,
186 struct i2c_device_identity *id);
190 * struct i2c_device_identity - i2c client device identification
191 * @manufacturer_id: 0 - 4095, database maintained by NXP
192 * @part_id: 0 - 511, according to manufacturer
193 * @die_revision: 0 - 7, according to manufacturer
195 struct i2c_device_identity {
197 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
198 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
199 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
200 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
201 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
202 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
203 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
204 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
205 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
206 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
207 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
208 #define I2C_DEVICE_ID_FLIR 11
209 #define I2C_DEVICE_ID_O2MICRO 12
210 #define I2C_DEVICE_ID_ATMEL 13
211 #define I2C_DEVICE_ID_NONE 0xffff
216 enum i2c_alert_protocol {
217 I2C_PROTOCOL_SMBUS_ALERT,
218 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
222 * struct i2c_driver - represent an I2C device driver
223 * @class: What kind of i2c device we instantiate (for detect)
224 * @probe: Callback for device binding - soon to be deprecated
225 * @probe_new: New callback for device binding
226 * @remove: Callback for device unbinding
227 * @shutdown: Callback for device shutdown
228 * @alert: Alert callback, for example for the SMBus alert protocol
229 * @command: Callback for bus-wide signaling (optional)
230 * @driver: Device driver model driver
231 * @id_table: List of I2C devices supported by this driver
232 * @detect: Callback for device detection
233 * @address_list: The I2C addresses to probe (for detect)
234 * @clients: List of detected clients we created (for i2c-core use only)
235 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
237 * The driver.owner field should be set to the module owner of this driver.
238 * The driver.name field should be set to the name of this driver.
240 * For automatic device detection, both @detect and @address_list must
241 * be defined. @class should also be set, otherwise only devices forced
242 * with module parameters will be created. The detect function must
243 * fill at least the name field of the i2c_board_info structure it is
244 * handed upon successful detection, and possibly also the flags field.
246 * If @detect is missing, the driver will still work fine for enumerated
247 * devices. Detected devices simply won't be supported. This is expected
248 * for the many I2C/SMBus devices which can't be detected reliably, and
249 * the ones which can always be enumerated in practice.
251 * The i2c_client structure which is handed to the @detect callback is
252 * not a real i2c_client. It is initialized just enough so that you can
253 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
254 * else with it. In particular, calling dev_dbg and friends on it is
260 /* Standard driver model interfaces */
261 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
262 int (*remove)(struct i2c_client *client);
264 /* New driver model interface to aid the seamless removal of the
265 * current probe()'s, more commonly unused than used second parameter.
267 int (*probe_new)(struct i2c_client *client);
269 /* driver model interfaces that don't relate to enumeration */
270 void (*shutdown)(struct i2c_client *client);
272 /* Alert callback, for example for the SMBus alert protocol.
273 * The format and meaning of the data value depends on the protocol.
274 * For the SMBus alert protocol, there is a single bit of data passed
275 * as the alert response's low bit ("event flag").
276 * For the SMBus Host Notify protocol, the data corresponds to the
277 * 16-bit payload data reported by the slave device acting as master.
279 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol,
282 /* a ioctl like command that can be used to perform specific functions
285 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
287 struct device_driver driver;
288 const struct i2c_device_id *id_table;
290 /* Device detection callback for automatic device creation */
291 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
292 const unsigned short *address_list;
293 struct list_head clients;
295 bool disable_i2c_core_irq_mapping;
297 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
300 * struct i2c_client - represent an I2C slave device
301 * @flags: see I2C_CLIENT_* for possible flags
302 * @addr: Address used on the I2C bus connected to the parent adapter.
303 * @name: Indicates the type of the device, usually a chip name that's
304 * generic enough to hide second-sourcing and compatible revisions.
305 * @adapter: manages the bus segment hosting this I2C device
306 * @dev: Driver model device node for the slave.
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 extern struct i2c_client *i2c_verify_client(struct device *dev);
344 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
345 extern 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 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
376 extern int i2c_slave_unregister(struct i2c_client *client);
377 extern 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.
446 extern struct i2c_client *
447 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
449 /* If you don't know the exact address of an I2C device, use this variant
450 * instead, which can probe for device presence in a list of possible
451 * addresses. The "probe" callback function is optional. If it is provided,
452 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
453 * a default probing method is used.
455 extern struct i2c_client *
456 i2c_new_probed_device(struct i2c_adapter *adap,
457 struct i2c_board_info *info,
458 unsigned short const *addr_list,
459 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
461 /* Common custom probe functions */
462 extern int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
464 /* For devices that use several addresses, use i2c_new_dummy() to make
465 * client handles for the extra addresses.
467 extern struct i2c_client *
468 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
470 extern struct i2c_client *
471 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
473 extern struct i2c_client *
474 i2c_new_secondary_device(struct i2c_client *client,
478 extern 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.
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
581 u32 scl_int_delay_ns;
587 * struct i2c_bus_recovery_info - I2C bus recovery information
588 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
589 * i2c_generic_scl_recovery().
590 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
591 * recovery. Populated internally for generic GPIO recovery.
592 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
593 * Populated internally for generic GPIO recovery.
594 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
595 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
596 * GPIO, for generic GPIO recovery.
597 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
598 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
599 * for generic GPIO recovery.
600 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
601 * has a more complex internal logic than just reading SDA. Optional.
602 * @prepare_recovery: This will be called before starting recovery. Platform may
603 * configure padmux here for SDA/SCL line or something else they want.
604 * @unprepare_recovery: This will be called after completing recovery. Platform
605 * may configure padmux here for SDA/SCL line or something else they want.
606 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
607 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
609 struct i2c_bus_recovery_info {
610 int (*recover_bus)(struct i2c_adapter *adap);
612 int (*get_scl)(struct i2c_adapter *adap);
613 void (*set_scl)(struct i2c_adapter *adap, int val);
614 int (*get_sda)(struct i2c_adapter *adap);
615 void (*set_sda)(struct i2c_adapter *adap, int val);
616 int (*get_bus_free)(struct i2c_adapter *adap);
618 void (*prepare_recovery)(struct i2c_adapter *adap);
619 void (*unprepare_recovery)(struct i2c_adapter *adap);
622 struct gpio_desc *scl_gpiod;
623 struct gpio_desc *sda_gpiod;
626 int i2c_recover_bus(struct i2c_adapter *adap);
628 /* Generic recovery routines */
629 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
632 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
633 * @flags: see I2C_AQ_* for possible flags and read below
634 * @max_num_msgs: maximum number of messages per transfer
635 * @max_write_len: maximum length of a write message
636 * @max_read_len: maximum length of a read message
637 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
638 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
640 * Note about combined messages: Some I2C controllers can only send one message
641 * per transfer, plus something called combined message or write-then-read.
642 * This is (usually) a small write message followed by a read message and
643 * barely enough to access register based devices like EEPROMs. There is a flag
644 * to support this mode. It implies max_num_msg = 2 and does the length checks
645 * with max_comb_*_len because combined message mode usually has its own
646 * limitations. Because of HW implementations, some controllers can actually do
647 * write-then-anything or other variants. To support that, write-then-read has
648 * been broken out into smaller bits like write-first and read-second which can
649 * be combined as needed.
652 struct i2c_adapter_quirks {
657 u16 max_comb_1st_msg_len;
658 u16 max_comb_2nd_msg_len;
661 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
662 #define I2C_AQ_COMB BIT(0)
663 /* first combined message must be write */
664 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
665 /* second combined message must be read */
666 #define I2C_AQ_COMB_READ_SECOND BIT(2)
667 /* both combined messages must have the same target address */
668 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
669 /* convenience macro for typical write-then read case */
670 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
671 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
672 /* clock stretching is not supported */
673 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
674 /* message cannot have length of 0 */
675 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
676 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
677 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
680 * i2c_adapter is the structure used to identify a physical i2c bus along
681 * with the access algorithms necessary to access it.
684 struct module *owner;
685 unsigned int class; /* classes to allow probing for */
686 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
689 /* data fields that are valid for all devices */
690 const struct i2c_lock_operations *lock_ops;
691 struct rt_mutex bus_lock;
692 struct rt_mutex mux_lock;
694 int timeout; /* in jiffies */
696 struct device dev; /* the adapter device */
697 unsigned long locked_flags; /* owned by the I2C core */
698 #define I2C_ALF_IS_SUSPENDED 0
699 #define I2C_ALF_SUSPEND_REPORTED 1
703 struct completion dev_released;
705 struct mutex userspace_clients_lock;
706 struct list_head userspace_clients;
708 struct i2c_bus_recovery_info *bus_recovery_info;
709 const struct i2c_adapter_quirks *quirks;
711 struct irq_domain *host_notify_domain;
713 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
715 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
717 return dev_get_drvdata(&adap->dev);
720 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
722 dev_set_drvdata(&adap->dev, data);
725 static inline struct i2c_adapter *
726 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
728 #if IS_ENABLED(CONFIG_I2C_MUX)
729 struct device *parent = adapter->dev.parent;
731 if (parent != NULL && parent->type == &i2c_adapter_type)
732 return to_i2c_adapter(parent);
738 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
740 /* Adapter locking functions, exported for shared pin cases */
741 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
742 #define I2C_LOCK_SEGMENT BIT(1)
745 * i2c_lock_bus - Get exclusive access to an I2C bus segment
746 * @adapter: Target I2C bus segment
747 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
748 * locks only this branch in the adapter tree
751 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
753 adapter->lock_ops->lock_bus(adapter, flags);
757 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
758 * @adapter: Target I2C bus segment
759 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
760 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
762 * Return: true if the I2C bus segment is locked, false otherwise
765 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
767 return adapter->lock_ops->trylock_bus(adapter, flags);
771 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
772 * @adapter: Target I2C bus segment
773 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
774 * unlocks only this branch in the adapter tree
777 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
779 adapter->lock_ops->unlock_bus(adapter, flags);
783 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
784 * @adap: Adapter to mark as suspended
786 * When using this helper to mark an adapter as suspended, the core will reject
787 * further transfers to this adapter. The usage of this helper is optional but
788 * recommended for devices having distinct handlers for system suspend and
789 * runtime suspend. More complex devices are free to implement custom solutions
790 * to reject transfers when suspended.
792 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
794 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
795 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
796 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
800 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
801 * @adap: Adapter to mark as resumed
803 * When using this helper to mark an adapter as resumed, the core will allow
804 * further transfers to this adapter. See also further notes to
805 * @i2c_mark_adapter_suspended().
807 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
809 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
810 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
811 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
814 /* i2c adapter classes (bitmask) */
815 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
816 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
817 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
818 /* Warn users that the adapter doesn't support classes anymore */
819 #define I2C_CLASS_DEPRECATED (1<<8)
821 /* Internal numbers to terminate lists */
822 #define I2C_CLIENT_END 0xfffeU
824 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
825 #define I2C_ADDRS(addr, addrs...) \
826 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
829 /* ----- functions exported by i2c.o */
833 #if IS_ENABLED(CONFIG_I2C)
834 extern int i2c_add_adapter(struct i2c_adapter *adap);
835 extern void i2c_del_adapter(struct i2c_adapter *adap);
836 extern int i2c_add_numbered_adapter(struct i2c_adapter *adap);
838 extern int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
839 extern void i2c_del_driver(struct i2c_driver *driver);
841 /* use a define to avoid include chaining to get THIS_MODULE */
842 #define i2c_add_driver(driver) \
843 i2c_register_driver(THIS_MODULE, driver)
845 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
846 extern void i2c_release_client(struct i2c_client *client);
848 /* call the i2c_client->command() of all attached clients with
849 * the given arguments */
850 extern void i2c_clients_command(struct i2c_adapter *adap,
851 unsigned int cmd, void *arg);
853 extern struct i2c_adapter *i2c_get_adapter(int nr);
854 extern void i2c_put_adapter(struct i2c_adapter *adap);
855 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
857 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
859 /* Return the functionality mask */
860 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
862 return adap->algo->functionality(adap);
865 /* Return 1 if adapter supports everything we need, 0 if not. */
866 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
868 return (func & i2c_get_functionality(adap)) == func;
872 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
874 * @quirks: quirk flags
876 * Return: true if the adapter has all the specified quirk flags, false if not
878 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
882 return (adap->quirks->flags & quirks) == quirks;
885 /* Return the adapter number for a specific adapter */
886 static inline int i2c_adapter_id(struct i2c_adapter *adap)
891 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
893 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
896 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
897 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
899 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
901 * module_i2c_driver() - Helper macro for registering a modular I2C driver
902 * @__i2c_driver: i2c_driver struct
904 * Helper macro for I2C drivers which do not do anything special in module
905 * init/exit. This eliminates a lot of boilerplate. Each module may only
906 * use this macro once, and calling it replaces module_init() and module_exit()
908 #define module_i2c_driver(__i2c_driver) \
909 module_driver(__i2c_driver, i2c_add_driver, \
913 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
914 * @__i2c_driver: i2c_driver struct
916 * Helper macro for I2C drivers which do not do anything special in their
917 * init. This eliminates a lot of boilerplate. Each driver may only
918 * use this macro once, and calling it replaces device_initcall().
920 #define builtin_i2c_driver(__i2c_driver) \
921 builtin_driver(__i2c_driver, i2c_add_driver)
925 #if IS_ENABLED(CONFIG_OF)
926 /* must call put_device() when done with returned i2c_client device */
927 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
929 /* must call put_device() when done with returned i2c_adapter device */
930 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
932 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
933 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
935 extern const struct of_device_id
936 *i2c_of_match_device(const struct of_device_id *matches,
937 struct i2c_client *client);
939 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
940 struct i2c_board_info *info);
944 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
949 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
954 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
959 static inline const struct of_device_id
960 *i2c_of_match_device(const struct of_device_id *matches,
961 struct i2c_client *client)
966 static inline int of_i2c_get_board_info(struct device *dev,
967 struct device_node *node,
968 struct i2c_board_info *info)
973 #endif /* CONFIG_OF */
975 struct acpi_resource;
976 struct acpi_resource_i2c_serialbus;
978 #if IS_ENABLED(CONFIG_ACPI)
979 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
980 struct acpi_resource_i2c_serialbus **i2c);
981 u32 i2c_acpi_find_bus_speed(struct device *dev);
982 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
983 struct i2c_board_info *info);
984 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
986 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
987 struct acpi_resource_i2c_serialbus **i2c)
991 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
995 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
996 int index, struct i2c_board_info *info)
1000 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
1004 #endif /* CONFIG_ACPI */
1006 #endif /* _LINUX_I2C_H */