include/linux/i2c.h

1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3  * i2c.h - definitions for the Linux i2c bus interface
4  * Copyright (C) 1995-2000 Simon G. Vogl
5  * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org>
24 #include <uapi/linux/i2c.h>
30 /* --- General options ------------------------------------------------	*/
43 /* I2C Frequency Modes */
61  * transmit one message at a time, a more complex version can be used to
69  * i2c_master_recv - issue a single I2C message in master receive mode
83  * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
99  * i2c_master_send - issue a single I2C message in master transmit mode
113  * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
192 #endif /* I2C */
195  * struct i2c_device_identity - i2c client device identification
196  * @manufacturer_id: 0 - 4095, database maintained by NXP
197  * @part_id: 0 - 511, according to manufacturer
198  * @die_revision: 0 - 7, according to manufacturer
227  * enum i2c_driver_flags - Flags for an I2C device driver
236  * struct i2c_driver - represent an I2C device driver
237  * @class: What kind of i2c device we instantiate (for detect)
242  * @command: Callback for bus-wide signaling (optional)
244  * @id_table: List of I2C devices supported by this driver
246  * @address_list: The I2C addresses to probe (for detect)
247  * @clients: List of detected clients we created (for i2c-core use only)
261  * for the many I2C/SMBus devices which can't be detected reliably, and
286 	 * 16-bit payload data reported by the slave device acting as master.
309  * struct i2c_client - represent an I2C slave device
311  * @addr: Address used on the I2C bus connected to the parent adapter.
313  *	generic enough to hide second-sourcing and compatible revisions.
314  * @adapter: manages the bus segment hosting this I2C device
318  * @detected: member of an i2c_driver.clients list or i2c-core's
320  * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
326  * i2c bus. The behaviour exposed to Linux is defined by the driver
335 #define I2C_CLIENT_HOST_NOTIFY	0x40	/* We want to use I2C host notify */
340 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
370 	return dev_get_drvdata(&client->dev);  in i2c_get_clientdata()
375 	dev_set_drvdata(&client->dev, data);  in i2c_set_clientdata()
378 /* I2C slave support */
399  * struct i2c_board_info - template for device creation
403  * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
412  * I2C doesn't actually support hardware probing, although controllers and
417  * i2c_board_info is used to build tables of information listing I2C devices
420  * bus numbers identify adapters that aren't yet available.  For add-on boards,
438  * I2C_BOARD_INFO - macro used to list an i2c device and its address
444  * fields (such as associated irq, or device-specific platform_data)
453  * Add-on boards should register/unregister their devices; e.g. a board
454  * with integrated I2C, a config eeprom, sensors, and a codec that's
460 /* If you don't know the exact address of an I2C device, use this variant
494 #endif /* I2C */
496 /* Mainboard arch_initcall() code should register all its I2C devices.
497  * This is done at arch_initcall time, before declaring any i2c adapters.
498  * Modules for add-on boards must use other calls.
514  * struct i2c_algorithm - represent I2C transfer methods
519  * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this
521  *   into I2C transfers instead.
535  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
540  * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the
545 	 * If an adapter algorithm can't do I2C-level access, set xfer
548 	 * using common I2C messages.
585  * struct i2c_lock_operations - represent I2C locking operations
586  * @lock_bus: Get exclusive access to an I2C bus segment
587  * @trylock_bus: Try to get exclusive access to an I2C bus segment
588  * @unlock_bus: Release exclusive access to an I2C bus segment
599  * struct i2c_timings - I2C timing information
601  * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
602  * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
603  * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
604  * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
605  * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
606  * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
623  * struct i2c_bus_recovery_info - I2C bus recovery information
630  * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
633  * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
637  *	has a more complex internal logic than just reading SDA. Optional.
639  *	configure padmux here for SDA/SCL line or something else they want.
641  *	may configure padmux here for SDA/SCL line or something else they want.
643  * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
644  * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
646  * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
647  *      to the I2C bus. Optional. Populated internally for GPIO recovery, if
649  * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
679  * struct i2c_adapter_quirks - describe flaws of an i2c adapter
687  * Note about combined messages: Some I2C controllers can only send one message
688  * per transfer, plus something called combined message or write-then-read.
694  * write-then-anything or other variants. To support that, write-then-read has
695  * been broken out into smaller bits like write-first and read-second which can
716 /* convenience macro for typical write-then read case */
729  * i2c_adapter is the structure used to identify a physical i2c bus along
746 	unsigned long locked_flags;	/* owned by the I2C core */
772 	return dev_get_drvdata(&adap->dev);  in i2c_get_adapdata()
777 	dev_set_drvdata(&adap->dev, data);  in i2c_set_adapdata()
784 	struct device *parent = adapter->dev.parent;  in i2c_parent_is_i2c_adapter()
786 	if (parent != NULL && parent->type == &i2c_adapter_type)  in i2c_parent_is_i2c_adapter()
800  * i2c_lock_bus - Get exclusive access to an I2C bus segment
801  * @adapter: Target I2C bus segment
802  * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
808 	adapter->lock_ops->lock_bus(adapter, flags);  in i2c_lock_bus()
812  * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
813  * @adapter: Target I2C bus segment
814  * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
817  * Return: true if the I2C bus segment is locked, false otherwise
822 	return adapter->lock_ops->trylock_bus(adapter, flags);  in i2c_trylock_bus()
826  * i2c_unlock_bus - Release exclusive access to an I2C bus segment
827  * @adapter: Target I2C bus segment
828  * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
834 	adapter->lock_ops->unlock_bus(adapter, flags);  in i2c_unlock_bus()
838  * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
850 	set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);  in i2c_mark_adapter_suspended()
855  * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
865 	clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);  in i2c_mark_adapter_resumed()
869 /* i2c adapter classes (bitmask) */
877 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
882 /* ----- functions exported by i2c.o */
901 	return !IS_ERR_OR_NULL(client) && client->dev.driver;  in i2c_client_has_driver()
904 /* call the i2c_client->command() of all attached clients with
918 	return adap->algo->functionality(adap);  in i2c_get_functionality()
928  * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
929  * @adap: i2c adapter
936 	if (!adap->quirks)  in i2c_check_quirks()
938 	return (adap->quirks->flags & quirks) == quirks;  in i2c_check_quirks()
944 	return adap->nr;  in i2c_adapter_id()
949 	return (msg->addr << 1) | (msg->flags & I2C_M_RD);  in i2c_8bit_addr_from_msg()
957  * module_i2c_driver() - Helper macro for registering a modular I2C driver
960  * Helper macro for I2C drivers which do not do anything special in module
969  * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
972  * Helper macro for I2C drivers which do not do anything special in their
988 #else /* I2C */
1008 #endif /* !I2C */
1064 	return -ENOTSUPP;  in of_i2c_get_board_info()
1074 			       struct acpi_resource_i2c_serialbus **i2c);
1084 					     struct acpi_resource_i2c_serialbus **i2c)  in i2c_acpi_get_i2c_resource()  argument
1100 	return ERR_PTR(-ENODEV);  in i2c_acpi_new_device_by_fwnode()