1 /* ------------------------------------------------------------------------- */
3 /* i2c.h - definitions for the i2c-bus interface */
5 /* ------------------------------------------------------------------------- */
6 /* Copyright (C) 1995-2000 Simon G. Vogl
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 /* ------------------------------------------------------------------------- */
24 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
25 Frodo Looijaard <frodol@dds.nl> */
29 #include <linux/mod_devicetable.h>
30 #include <linux/device.h> /* for struct device */
31 #include <linux/sched.h> /* for completion */
32 #include <linux/mutex.h>
33 #include <linux/rtmutex.h>
34 #include <linux/irqdomain.h> /* for Host Notify IRQ */
35 #include <linux/of.h> /* for struct device_node */
36 #include <linux/swab.h> /* for swab16 */
37 #include <uapi/linux/i2c.h>
39 extern struct bus_type i2c_bus_type
;
40 extern struct device_type i2c_adapter_type
;
42 /* --- General options ------------------------------------------------ */
50 struct i2c_board_info
;
52 typedef int (*i2c_slave_cb_t
)(struct i2c_client
*, enum i2c_slave_event
, u8
*);
55 struct property_entry
;
57 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
59 * The master routines are the ones normally used to transmit data to devices
60 * on a bus (or read from them). Apart from two basic transfer functions to
61 * transmit one message at a time, a more complex version can be used to
62 * transmit an arbitrary number of messages without interruption.
63 * @count must be be less than 64k since msg.len is u16.
65 extern int i2c_master_send(const struct i2c_client
*client
, const char *buf
,
67 extern int i2c_master_recv(const struct i2c_client
*client
, char *buf
,
70 /* Transfer num messages.
72 extern int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
75 extern int __i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
78 /* This is the very generalized SMBus access routine. You probably do not
79 want to use this, though; one of the functions below may be much easier,
80 and probably just as fast.
81 Note that we use i2c_adapter here, because you do not need a specific
82 smbus adapter to call this function. */
83 extern s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
84 unsigned short flags
, char read_write
, u8 command
,
85 int size
, union i2c_smbus_data
*data
);
87 /* Now follow the 'nice' access routines. These also document the calling
88 conventions of i2c_smbus_xfer. */
90 extern s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
91 extern s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
92 extern s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
,
94 extern s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
95 u8 command
, u8 value
);
96 extern s32
i2c_smbus_read_word_data(const struct i2c_client
*client
,
98 extern s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
99 u8 command
, u16 value
);
102 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
104 s32 value
= i2c_smbus_read_word_data(client
, command
);
106 return (value
< 0) ? value
: swab16(value
);
110 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
111 u8 command
, u16 value
)
113 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
116 /* Returns the number of read bytes */
117 extern s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
118 u8 command
, u8
*values
);
119 extern s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
120 u8 command
, u8 length
, const u8
*values
);
121 /* Returns the number of read bytes */
122 extern s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
123 u8 command
, u8 length
, u8
*values
);
124 extern s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
125 u8 command
, u8 length
,
128 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client
*client
,
129 u8 command
, u8 length
, u8
*values
);
132 enum i2c_alert_protocol
{
133 I2C_PROTOCOL_SMBUS_ALERT
,
134 I2C_PROTOCOL_SMBUS_HOST_NOTIFY
,
138 * struct i2c_driver - represent an I2C device driver
139 * @class: What kind of i2c device we instantiate (for detect)
140 * @attach_adapter: Callback for bus addition (deprecated)
141 * @probe: Callback for device binding - soon to be deprecated
142 * @probe_new: New callback for device binding
143 * @remove: Callback for device unbinding
144 * @shutdown: Callback for device shutdown
145 * @alert: Alert callback, for example for the SMBus alert protocol
146 * @command: Callback for bus-wide signaling (optional)
147 * @driver: Device driver model driver
148 * @id_table: List of I2C devices supported by this driver
149 * @detect: Callback for device detection
150 * @address_list: The I2C addresses to probe (for detect)
151 * @clients: List of detected clients we created (for i2c-core use only)
152 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
154 * The driver.owner field should be set to the module owner of this driver.
155 * The driver.name field should be set to the name of this driver.
157 * For automatic device detection, both @detect and @address_list must
158 * be defined. @class should also be set, otherwise only devices forced
159 * with module parameters will be created. The detect function must
160 * fill at least the name field of the i2c_board_info structure it is
161 * handed upon successful detection, and possibly also the flags field.
163 * If @detect is missing, the driver will still work fine for enumerated
164 * devices. Detected devices simply won't be supported. This is expected
165 * for the many I2C/SMBus devices which can't be detected reliably, and
166 * the ones which can always be enumerated in practice.
168 * The i2c_client structure which is handed to the @detect callback is
169 * not a real i2c_client. It is initialized just enough so that you can
170 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
171 * else with it. In particular, calling dev_dbg and friends on it is
177 /* Notifies the driver that a new bus has appeared. You should avoid
178 * using this, it will be removed in a near future.
180 int (*attach_adapter
)(struct i2c_adapter
*) __deprecated
;
182 /* Standard driver model interfaces */
183 int (*probe
)(struct i2c_client
*, const struct i2c_device_id
*);
184 int (*remove
)(struct i2c_client
*);
186 /* New driver model interface to aid the seamless removal of the
187 * current probe()'s, more commonly unused than used second parameter.
189 int (*probe_new
)(struct i2c_client
*);
191 /* driver model interfaces that don't relate to enumeration */
192 void (*shutdown
)(struct i2c_client
*);
194 /* Alert callback, for example for the SMBus alert protocol.
195 * The format and meaning of the data value depends on the protocol.
196 * For the SMBus alert protocol, there is a single bit of data passed
197 * as the alert response's low bit ("event flag").
198 * For the SMBus Host Notify protocol, the data corresponds to the
199 * 16-bit payload data reported by the slave device acting as master.
201 void (*alert
)(struct i2c_client
*, enum i2c_alert_protocol protocol
,
204 /* a ioctl like command that can be used to perform specific functions
207 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
209 struct device_driver driver
;
210 const struct i2c_device_id
*id_table
;
212 /* Device detection callback for automatic device creation */
213 int (*detect
)(struct i2c_client
*, struct i2c_board_info
*);
214 const unsigned short *address_list
;
215 struct list_head clients
;
217 bool disable_i2c_core_irq_mapping
;
219 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
222 * struct i2c_client - represent an I2C slave device
223 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
224 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
225 * @addr: Address used on the I2C bus connected to the parent adapter.
226 * @name: Indicates the type of the device, usually a chip name that's
227 * generic enough to hide second-sourcing and compatible revisions.
228 * @adapter: manages the bus segment hosting this I2C device
229 * @dev: Driver model device node for the slave.
230 * @irq: indicates the IRQ generated by this device (if any)
231 * @detected: member of an i2c_driver.clients list or i2c-core's
232 * userspace_devices list
233 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
234 * calls it to pass on slave events to the slave driver.
236 * An i2c_client identifies a single device (i.e. chip) connected to an
237 * i2c bus. The behaviour exposed to Linux is defined by the driver
238 * managing the device.
241 unsigned short flags
; /* div., see below */
242 unsigned short addr
; /* chip address - NOTE: 7bit */
243 /* addresses are stored in the */
245 char name
[I2C_NAME_SIZE
];
246 struct i2c_adapter
*adapter
; /* the adapter we sit on */
247 struct device dev
; /* the device structure */
248 int irq
; /* irq issued by device */
249 struct list_head detected
;
250 #if IS_ENABLED(CONFIG_I2C_SLAVE)
251 i2c_slave_cb_t slave_cb
; /* callback for slave mode */
254 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
256 extern struct i2c_client
*i2c_verify_client(struct device
*dev
);
257 extern struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
258 extern const struct i2c_device_id
*i2c_match_id(const struct i2c_device_id
*id
,
259 const struct i2c_client
*client
);
261 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
263 struct device
* const dev
= container_of(kobj
, struct device
, kobj
);
264 return to_i2c_client(dev
);
267 static inline void *i2c_get_clientdata(const struct i2c_client
*dev
)
269 return dev_get_drvdata(&dev
->dev
);
272 static inline void i2c_set_clientdata(struct i2c_client
*dev
, void *data
)
274 dev_set_drvdata(&dev
->dev
, data
);
277 /* I2C slave support */
279 #if IS_ENABLED(CONFIG_I2C_SLAVE)
280 enum i2c_slave_event
{
281 I2C_SLAVE_READ_REQUESTED
,
282 I2C_SLAVE_WRITE_REQUESTED
,
283 I2C_SLAVE_READ_PROCESSED
,
284 I2C_SLAVE_WRITE_RECEIVED
,
288 extern int i2c_slave_register(struct i2c_client
*client
, i2c_slave_cb_t slave_cb
);
289 extern int i2c_slave_unregister(struct i2c_client
*client
);
290 extern bool i2c_detect_slave_mode(struct device
*dev
);
292 static inline int i2c_slave_event(struct i2c_client
*client
,
293 enum i2c_slave_event event
, u8
*val
)
295 return client
->slave_cb(client
, event
, val
);
300 * struct i2c_board_info - template for device creation
301 * @type: chip type, to initialize i2c_client.name
302 * @flags: to initialize i2c_client.flags
303 * @addr: stored in i2c_client.addr
304 * @platform_data: stored in i2c_client.dev.platform_data
305 * @archdata: copied into i2c_client.dev.archdata
306 * @of_node: pointer to OpenFirmware device node
307 * @fwnode: device node supplied by the platform firmware
308 * @properties: additional device properties for the device
309 * @irq: stored in i2c_client.irq
311 * I2C doesn't actually support hardware probing, although controllers and
312 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
313 * a device at a given address. Drivers commonly need more information than
314 * that, such as chip type, configuration, associated IRQ, and so on.
316 * i2c_board_info is used to build tables of information listing I2C devices
317 * that are present. This information is used to grow the driver model tree.
318 * For mainboards this is done statically using i2c_register_board_info();
319 * bus numbers identify adapters that aren't yet available. For add-on boards,
320 * i2c_new_device() does this dynamically with the adapter already known.
322 struct i2c_board_info
{
323 char type
[I2C_NAME_SIZE
];
324 unsigned short flags
;
327 struct dev_archdata
*archdata
;
328 struct device_node
*of_node
;
329 struct fwnode_handle
*fwnode
;
330 const struct property_entry
*properties
;
335 * I2C_BOARD_INFO - macro used to list an i2c device and its address
336 * @dev_type: identifies the device type
337 * @dev_addr: the device's address on the bus.
339 * This macro initializes essential fields of a struct i2c_board_info,
340 * declaring what has been provided on a particular board. Optional
341 * fields (such as associated irq, or device-specific platform_data)
342 * are provided using conventional syntax.
344 #define I2C_BOARD_INFO(dev_type, dev_addr) \
345 .type = dev_type, .addr = (dev_addr)
348 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
349 /* Add-on boards should register/unregister their devices; e.g. a board
350 * with integrated I2C, a config eeprom, sensors, and a codec that's
351 * used in conjunction with the primary hardware.
353 extern struct i2c_client
*
354 i2c_new_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
356 /* If you don't know the exact address of an I2C device, use this variant
357 * instead, which can probe for device presence in a list of possible
358 * addresses. The "probe" callback function is optional. If it is provided,
359 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
360 * a default probing method is used.
362 extern struct i2c_client
*
363 i2c_new_probed_device(struct i2c_adapter
*adap
,
364 struct i2c_board_info
*info
,
365 unsigned short const *addr_list
,
366 int (*probe
)(struct i2c_adapter
*, unsigned short addr
));
368 /* Common custom probe functions */
369 extern int i2c_probe_func_quick_read(struct i2c_adapter
*, unsigned short addr
);
371 /* For devices that use several addresses, use i2c_new_dummy() to make
372 * client handles for the extra addresses.
374 extern struct i2c_client
*
375 i2c_new_dummy(struct i2c_adapter
*adap
, u16 address
);
377 extern struct i2c_client
*
378 i2c_new_secondary_device(struct i2c_client
*client
,
382 extern void i2c_unregister_device(struct i2c_client
*);
385 /* Mainboard arch_initcall() code should register all its I2C devices.
386 * This is done at arch_initcall time, before declaring any i2c adapters.
387 * Modules for add-on boards must use other calls.
389 #ifdef CONFIG_I2C_BOARDINFO
391 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
395 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
400 #endif /* I2C_BOARDINFO */
403 * struct i2c_algorithm - represent I2C transfer method
404 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
405 * defined by the msgs array, with num messages available to transfer via
406 * the adapter specified by adap.
407 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
408 * is not present, then the bus layer will try and convert the SMBus calls
409 * into I2C transfers instead.
410 * @functionality: Return the flags that this algorithm/adapter pair supports
411 * from the I2C_FUNC_* flags.
412 * @reg_slave: Register given client to I2C slave mode of this adapter
413 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
415 * The following structs are for those who like to implement new bus drivers:
416 * i2c_algorithm is the interface to a class of hardware solutions which can
417 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
418 * to name two of the most common.
420 * The return codes from the @master_xfer field should indicate the type of
421 * error code that occurred during the transfer, as documented in the kernel
422 * Documentation file Documentation/i2c/fault-codes.
424 struct i2c_algorithm
{
425 /* If an adapter algorithm can't do I2C-level access, set master_xfer
426 to NULL. If an adapter algorithm can do SMBus access, set
427 smbus_xfer. If set to NULL, the SMBus protocol is simulated
428 using common I2C messages */
429 /* master_xfer should return the number of messages successfully
430 processed, or a negative value on error */
431 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
433 int (*smbus_xfer
) (struct i2c_adapter
*adap
, u16 addr
,
434 unsigned short flags
, char read_write
,
435 u8 command
, int size
, union i2c_smbus_data
*data
);
437 /* To determine what the adapter supports */
438 u32 (*functionality
) (struct i2c_adapter
*);
440 #if IS_ENABLED(CONFIG_I2C_SLAVE)
441 int (*reg_slave
)(struct i2c_client
*client
);
442 int (*unreg_slave
)(struct i2c_client
*client
);
447 * struct i2c_lock_operations - represent I2C locking operations
448 * @lock_bus: Get exclusive access to an I2C bus segment
449 * @trylock_bus: Try to get exclusive access to an I2C bus segment
450 * @unlock_bus: Release exclusive access to an I2C bus segment
452 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
454 struct i2c_lock_operations
{
455 void (*lock_bus
)(struct i2c_adapter
*, unsigned int flags
);
456 int (*trylock_bus
)(struct i2c_adapter
*, unsigned int flags
);
457 void (*unlock_bus
)(struct i2c_adapter
*, unsigned int flags
);
461 * struct i2c_timings - I2C timing information
462 * @bus_freq_hz: the bus frequency in Hz
463 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
464 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
465 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
466 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
472 u32 scl_int_delay_ns
;
477 * struct i2c_bus_recovery_info - I2C bus recovery information
478 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
479 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
480 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
481 * recovery. Used internally for generic GPIO recovery.
482 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
483 * internally for generic GPIO recovery.
484 * @get_sda: This gets current value of SDA line. Optional for generic SCL
485 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
487 * @prepare_recovery: This will be called before starting recovery. Platform may
488 * configure padmux here for SDA/SCL line or something else they want.
489 * @unprepare_recovery: This will be called after completing recovery. Platform
490 * may configure padmux here for SDA/SCL line or something else they want.
491 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
492 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
494 struct i2c_bus_recovery_info
{
495 int (*recover_bus
)(struct i2c_adapter
*);
497 int (*get_scl
)(struct i2c_adapter
*);
498 void (*set_scl
)(struct i2c_adapter
*, int val
);
499 int (*get_sda
)(struct i2c_adapter
*);
501 void (*prepare_recovery
)(struct i2c_adapter
*);
502 void (*unprepare_recovery
)(struct i2c_adapter
*);
509 int i2c_recover_bus(struct i2c_adapter
*adap
);
511 /* Generic recovery routines */
512 int i2c_generic_gpio_recovery(struct i2c_adapter
*adap
);
513 int i2c_generic_scl_recovery(struct i2c_adapter
*adap
);
516 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
517 * @flags: see I2C_AQ_* for possible flags and read below
518 * @max_num_msgs: maximum number of messages per transfer
519 * @max_write_len: maximum length of a write message
520 * @max_read_len: maximum length of a read message
521 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
522 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
524 * Note about combined messages: Some I2C controllers can only send one message
525 * per transfer, plus something called combined message or write-then-read.
526 * This is (usually) a small write message followed by a read message and
527 * barely enough to access register based devices like EEPROMs. There is a flag
528 * to support this mode. It implies max_num_msg = 2 and does the length checks
529 * with max_comb_*_len because combined message mode usually has its own
530 * limitations. Because of HW implementations, some controllers can actually do
531 * write-then-anything or other variants. To support that, write-then-read has
532 * been broken out into smaller bits like write-first and read-second which can
533 * be combined as needed.
536 struct i2c_adapter_quirks
{
541 u16 max_comb_1st_msg_len
;
542 u16 max_comb_2nd_msg_len
;
545 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
546 #define I2C_AQ_COMB BIT(0)
547 /* first combined message must be write */
548 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
549 /* second combined message must be read */
550 #define I2C_AQ_COMB_READ_SECOND BIT(2)
551 /* both combined messages must have the same target address */
552 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
553 /* convenience macro for typical write-then read case */
554 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
555 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
556 /* clock stretching is not supported */
557 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
560 * i2c_adapter is the structure used to identify a physical i2c bus along
561 * with the access algorithms necessary to access it.
564 struct module
*owner
;
565 unsigned int class; /* classes to allow probing for */
566 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
569 /* data fields that are valid for all devices */
570 const struct i2c_lock_operations
*lock_ops
;
571 struct rt_mutex bus_lock
;
572 struct rt_mutex mux_lock
;
574 int timeout
; /* in jiffies */
576 struct device dev
; /* the adapter device */
580 struct completion dev_released
;
582 struct mutex userspace_clients_lock
;
583 struct list_head userspace_clients
;
585 struct i2c_bus_recovery_info
*bus_recovery_info
;
586 const struct i2c_adapter_quirks
*quirks
;
588 struct irq_domain
*host_notify_domain
;
590 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
592 static inline void *i2c_get_adapdata(const struct i2c_adapter
*dev
)
594 return dev_get_drvdata(&dev
->dev
);
597 static inline void i2c_set_adapdata(struct i2c_adapter
*dev
, void *data
)
599 dev_set_drvdata(&dev
->dev
, data
);
602 static inline struct i2c_adapter
*
603 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
605 #if IS_ENABLED(CONFIG_I2C_MUX)
606 struct device
*parent
= adapter
->dev
.parent
;
608 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
609 return to_i2c_adapter(parent
);
615 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*, void *));
617 /* Adapter locking functions, exported for shared pin cases */
618 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
619 #define I2C_LOCK_SEGMENT BIT(1)
622 * i2c_lock_bus - Get exclusive access to an I2C bus segment
623 * @adapter: Target I2C bus segment
624 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
625 * locks only this branch in the adapter tree
628 i2c_lock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
630 adapter
->lock_ops
->lock_bus(adapter
, flags
);
634 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
635 * @adapter: Target I2C bus segment
636 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
637 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
639 * Return: true if the I2C bus segment is locked, false otherwise
642 i2c_trylock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
644 return adapter
->lock_ops
->trylock_bus(adapter
, flags
);
648 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
649 * @adapter: Target I2C bus segment
650 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
651 * unlocks only this branch in the adapter tree
654 i2c_unlock_bus(struct i2c_adapter
*adapter
, unsigned int flags
)
656 adapter
->lock_ops
->unlock_bus(adapter
, flags
);
660 i2c_lock_adapter(struct i2c_adapter
*adapter
)
662 i2c_lock_bus(adapter
, I2C_LOCK_ROOT_ADAPTER
);
666 i2c_unlock_adapter(struct i2c_adapter
*adapter
)
668 i2c_unlock_bus(adapter
, I2C_LOCK_ROOT_ADAPTER
);
671 /*flags for the client struct: */
672 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
673 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
674 /* Must equal I2C_M_TEN below */
675 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
676 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
677 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
678 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
679 /* Must match I2C_M_STOP|IGNORE_NAK */
681 /* i2c adapter classes (bitmask) */
682 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
683 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
684 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
685 #define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
687 /* Internal numbers to terminate lists */
688 #define I2C_CLIENT_END 0xfffeU
690 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
691 #define I2C_ADDRS(addr, addrs...) \
692 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
695 /* ----- functions exported by i2c.o */
699 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
700 extern int i2c_add_adapter(struct i2c_adapter
*);
701 extern void i2c_del_adapter(struct i2c_adapter
*);
702 extern int i2c_add_numbered_adapter(struct i2c_adapter
*);
704 extern int i2c_register_driver(struct module
*, struct i2c_driver
*);
705 extern void i2c_del_driver(struct i2c_driver
*);
707 /* use a define to avoid include chaining to get THIS_MODULE */
708 #define i2c_add_driver(driver) \
709 i2c_register_driver(THIS_MODULE, driver)
711 extern struct i2c_client
*i2c_use_client(struct i2c_client
*client
);
712 extern void i2c_release_client(struct i2c_client
*client
);
714 /* call the i2c_client->command() of all attached clients with
715 * the given arguments */
716 extern void i2c_clients_command(struct i2c_adapter
*adap
,
717 unsigned int cmd
, void *arg
);
719 extern struct i2c_adapter
*i2c_get_adapter(int nr
);
720 extern void i2c_put_adapter(struct i2c_adapter
*adap
);
721 extern unsigned int i2c_adapter_depth(struct i2c_adapter
*adapter
);
723 void i2c_parse_fw_timings(struct device
*dev
, struct i2c_timings
*t
, bool use_defaults
);
725 /* Return the functionality mask */
726 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
728 return adap
->algo
->functionality(adap
);
731 /* Return 1 if adapter supports everything we need, 0 if not. */
732 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
734 return (func
& i2c_get_functionality(adap
)) == func
;
738 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
740 * @quirks: quirk flags
742 * Return: true if the adapter has all the specified quirk flags, false if not
744 static inline bool i2c_check_quirks(struct i2c_adapter
*adap
, u64 quirks
)
748 return (adap
->quirks
->flags
& quirks
) == quirks
;
751 /* Return the adapter number for a specific adapter */
752 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
757 static inline u8
i2c_8bit_addr_from_msg(const struct i2c_msg
*msg
)
759 return (msg
->addr
<< 1) | (msg
->flags
& I2C_M_RD
? 1 : 0);
762 int i2c_handle_smbus_host_notify(struct i2c_adapter
*adap
, unsigned short addr
);
764 * module_i2c_driver() - Helper macro for registering a modular I2C driver
765 * @__i2c_driver: i2c_driver struct
767 * Helper macro for I2C drivers which do not do anything special in module
768 * init/exit. This eliminates a lot of boilerplate. Each module may only
769 * use this macro once, and calling it replaces module_init() and module_exit()
771 #define module_i2c_driver(__i2c_driver) \
772 module_driver(__i2c_driver, i2c_add_driver, \
776 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
777 * @__i2c_driver: i2c_driver struct
779 * Helper macro for I2C drivers which do not do anything special in their
780 * init. This eliminates a lot of boilerplate. Each driver may only
781 * use this macro once, and calling it replaces device_initcall().
783 #define builtin_i2c_driver(__i2c_driver) \
784 builtin_driver(__i2c_driver, i2c_add_driver)
788 #if IS_ENABLED(CONFIG_OF)
789 /* must call put_device() when done with returned i2c_client device */
790 extern struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
);
792 /* must call put_device() when done with returned i2c_adapter device */
793 extern struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
);
795 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
796 struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
);
798 extern const struct of_device_id
799 *i2c_of_match_device(const struct of_device_id
*matches
,
800 struct i2c_client
*client
);
804 static inline struct i2c_client
*of_find_i2c_device_by_node(struct device_node
*node
)
809 static inline struct i2c_adapter
*of_find_i2c_adapter_by_node(struct device_node
*node
)
814 static inline struct i2c_adapter
*of_get_i2c_adapter_by_node(struct device_node
*node
)
819 static inline const struct of_device_id
820 *i2c_of_match_device(const struct of_device_id
*matches
,
821 struct i2c_client
*client
)
826 #endif /* CONFIG_OF */
828 #if IS_ENABLED(CONFIG_ACPI)
829 u32
i2c_acpi_find_bus_speed(struct device
*dev
);
830 struct i2c_client
*i2c_acpi_new_device(struct device
*dev
, int index
,
831 struct i2c_board_info
*info
);
833 static inline u32
i2c_acpi_find_bus_speed(struct device
*dev
)
837 static inline struct i2c_client
*i2c_acpi_new_device(struct device
*dev
,
838 int index
, struct i2c_board_info
*info
)
842 #endif /* CONFIG_ACPI */
844 #endif /* _LINUX_I2C_H */