833 lines
30 KiB
C
833 lines
30 KiB
C
/* ------------------------------------------------------------------------- */
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/* */
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/* i2c.h - definitions for the i2c-bus interface */
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/* */
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/* ------------------------------------------------------------------------- */
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/* Copyright (C) 1995-2000 Simon G. Vogl
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301 USA. */
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/* ------------------------------------------------------------------------- */
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/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
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Frodo Looijaard <frodol@dds.nl> */
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#ifndef _LINUX_I2C_H
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#define _LINUX_I2C_H
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#include <linux/mod_devicetable.h>
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#include <linux/device.h> /* for struct device */
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#include <linux/sched.h> /* for completion */
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#include <linux/mutex.h>
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#include <linux/of.h> /* for struct device_node */
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#include <linux/swab.h> /* for swab16 */
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#include <uapi/linux/i2c.h>
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extern struct bus_type i2c_bus_type;
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extern struct device_type i2c_adapter_type;
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/* --- General options ------------------------------------------------ */
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struct i2c_msg;
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struct i2c_algorithm;
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struct i2c_adapter;
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struct i2c_client;
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struct i2c_driver;
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union i2c_smbus_data;
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struct i2c_board_info;
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enum i2c_slave_event;
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typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event,
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void *);
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struct module;
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#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
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/*
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* The master routines are the ones normally used to transmit data to devices
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* on a bus (or read from them). Apart from two basic transfer functions to
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* transmit one message at a time, a more complex version can be used to
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* transmit an arbitrary number of messages without interruption.
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* @count must be be less than 64k since msg.len is u16.
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*/
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extern int i2c_master_send(const struct i2c_client *client, const char *buf,
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int count);
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extern int i2c_master_recv(const struct i2c_client *client, char *buf,
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int count);
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/* Transfer num messages.
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*/
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extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
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int num);
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/* Unlocked flavor */
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extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
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int num);
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/* Change bus clock rate for i2c adapter */
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extern int i2c_set_adapter_bus_clk_rate(struct i2c_adapter *adap, int bus_rate);
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extern int i2c_get_adapter_bus_clk_rate(struct i2c_adapter *adap);
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/* This is the very generalized SMBus access routine. You probably do not
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want to use this, though; one of the functions below may be much easier,
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and probably just as fast.
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Note that we use i2c_adapter here, because you do not need a specific
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smbus adapter to call this function. */
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extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
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unsigned short flags, char read_write, u8 command,
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int size, union i2c_smbus_data *data);
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/* Now follow the 'nice' access routines. These also document the calling
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conventions of i2c_smbus_xfer. */
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extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
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extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
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extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
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u8 command);
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extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
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u8 command, u8 value);
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extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
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u8 command);
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extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
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u8 command, u16 value);
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static inline s32
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i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
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{
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s32 value = i2c_smbus_read_word_data(client, command);
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return (value < 0) ? value : swab16(value);
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}
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static inline s32
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i2c_smbus_write_word_swapped(const struct i2c_client *client,
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u8 command, u16 value)
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{
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return i2c_smbus_write_word_data(client, command, swab16(value));
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}
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/* Returns the number of read bytes */
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extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
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u8 command, u8 *values);
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extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
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u8 command, u8 length, const u8 *values);
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/* Returns the number of read bytes */
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extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
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u8 command, u8 length, u8 *values);
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extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
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u8 command, u8 length,
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const u8 *values);
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extern s32
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i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
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u8 command, u8 length, u8 *values);
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#endif /* I2C */
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enum i2c_alert_protocol {
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I2C_PROTOCOL_SMBUS_ALERT,
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I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
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};
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/**
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* struct i2c_driver - represent an I2C device driver
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* @class: What kind of i2c device we instantiate (for detect)
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* @attach_adapter: Callback for bus addition (deprecated)
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* @probe: Callback for device binding
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* @remove: Callback for device unbinding
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* @shutdown: Callback for device shutdown
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* @alert: Alert callback, for example for the SMBus alert protocol
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* @command: Callback for bus-wide signaling (optional)
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* @driver: Device driver model driver
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* @id_table: List of I2C devices supported by this driver
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* @detect: Callback for device detection
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* @address_list: The I2C addresses to probe (for detect)
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* @clients: List of detected clients we created (for i2c-core use only)
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*
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* The driver.owner field should be set to the module owner of this driver.
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* The driver.name field should be set to the name of this driver.
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*
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* For automatic device detection, both @detect and @address_list must
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* be defined. @class should also be set, otherwise only devices forced
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* with module parameters will be created. The detect function must
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* fill at least the name field of the i2c_board_info structure it is
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* handed upon successful detection, and possibly also the flags field.
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*
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* If @detect is missing, the driver will still work fine for enumerated
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* devices. Detected devices simply won't be supported. This is expected
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* for the many I2C/SMBus devices which can't be detected reliably, and
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* the ones which can always be enumerated in practice.
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*
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* The i2c_client structure which is handed to the @detect callback is
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* not a real i2c_client. It is initialized just enough so that you can
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* call i2c_smbus_read_byte_data and friends on it. Don't do anything
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* else with it. In particular, calling dev_dbg and friends on it is
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* not allowed.
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*/
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struct i2c_driver {
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unsigned int class;
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/* Notifies the driver that a new bus has appeared. You should avoid
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* using this, it will be removed in a near future.
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*/
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int (*attach_adapter)(struct i2c_adapter *) __deprecated;
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/* Standard driver model interfaces */
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int (*probe)(struct i2c_client *, const struct i2c_device_id *);
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int (*remove)(struct i2c_client *);
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/* driver model interfaces that don't relate to enumeration */
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void (*shutdown)(struct i2c_client *);
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/* Alert callback, for example for the SMBus alert protocol.
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* The format and meaning of the data value depends on the protocol.
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* For the SMBus alert protocol, there is a single bit of data passed
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* as the alert response's low bit ("event flag").
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* For the SMBus Host Notify protocol, the data corresponds to the
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* 16-bit payload data reported by the slave device acting as master.
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*/
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void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
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unsigned int data);
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/* a ioctl like command that can be used to perform specific functions
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* with the device.
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*/
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int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
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struct device_driver driver;
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const struct i2c_device_id *id_table;
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/* Device detection callback for automatic device creation */
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int (*detect)(struct i2c_client *, struct i2c_board_info *);
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const unsigned short *address_list;
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struct list_head clients;
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};
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#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
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/**
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* struct i2c_client - represent an I2C slave device
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* @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
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* I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
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* @addr: Address used on the I2C bus connected to the parent adapter.
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* @name: Indicates the type of the device, usually a chip name that's
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* generic enough to hide second-sourcing and compatible revisions.
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* @adapter: manages the bus segment hosting this I2C device
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* @dev: Driver model device node for the slave.
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* @irq: indicates the IRQ generated by this device (if any)
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* @detected: member of an i2c_driver.clients list or i2c-core's
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* userspace_devices list
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* @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
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* calls it to pass on slave events to the slave driver.
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*
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* An i2c_client identifies a single device (i.e. chip) connected to an
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* i2c bus. The behaviour exposed to Linux is defined by the driver
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* managing the device.
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*/
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struct i2c_client {
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unsigned short flags; /* div., see below */
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unsigned short addr; /* chip address - NOTE: 7bit */
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/* addresses are stored in the */
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/* _LOWER_ 7 bits */
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char name[I2C_NAME_SIZE];
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struct i2c_adapter *adapter; /* the adapter we sit on */
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struct device dev; /* the device structure */
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int irq; /* irq issued by device */
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struct list_head detected;
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#if IS_ENABLED(CONFIG_I2C_SLAVE)
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i2c_slave_cb_t slave_cb; /* callback for slave mode */
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u32 buffer_size; /* slave buffer size */
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#endif
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};
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#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
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extern struct i2c_client *i2c_verify_client(struct device *dev);
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extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
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static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
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{
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struct device * const dev = container_of(kobj, struct device, kobj);
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return to_i2c_client(dev);
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}
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static inline void *i2c_get_clientdata(const struct i2c_client *dev)
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{
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return dev_get_drvdata(&dev->dev);
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}
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static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
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{
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dev_set_drvdata(&dev->dev, data);
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}
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/* I2C slave support */
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#if IS_ENABLED(CONFIG_I2C_SLAVE)
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enum i2c_slave_event {
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I2C_SLAVE_READ_REQUESTED,
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I2C_SLAVE_WRITE_REQUESTED,
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I2C_SLAVE_READ_PROCESSED,
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I2C_SLAVE_WRITE_RECEIVED,
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I2C_SLAVE_READ_BUFFER_REQUESTED,
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I2C_SLAVE_WRITE_BUFFER_REQUESTED,
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I2C_SLAVE_READ_BUFFER_PROCESSED,
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I2C_SLAVE_WRITE_BUFFER_RECEIVED,
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I2C_SLAVE_READ_BUFFER_COUNT,
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I2C_SLAVE_STOP,
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};
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struct i2c_slave_data {
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u8 *buf;
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u32 size;
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};
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extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
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extern int i2c_slave_unregister(struct i2c_client *client);
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static inline int i2c_slave_event(struct i2c_client *client,
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enum i2c_slave_event event, void *val)
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{
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return client->slave_cb(client, event, val);
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}
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#endif
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/**
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* struct i2c_board_info - template for device creation
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* @type: chip type, to initialize i2c_client.name
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* @flags: to initialize i2c_client.flags
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* @addr: stored in i2c_client.addr
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* @platform_data: stored in i2c_client.dev.platform_data
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* @archdata: copied into i2c_client.dev.archdata
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* @of_node: pointer to OpenFirmware device node
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* @fwnode: device node supplied by the platform firmware
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* @irq: stored in i2c_client.irq
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*
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* I2C doesn't actually support hardware probing, although controllers and
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* devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
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* a device at a given address. Drivers commonly need more information than
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* that, such as chip type, configuration, associated IRQ, and so on.
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*
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* i2c_board_info is used to build tables of information listing I2C devices
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* that are present. This information is used to grow the driver model tree.
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* For mainboards this is done statically using i2c_register_board_info();
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* bus numbers identify adapters that aren't yet available. For add-on boards,
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* i2c_new_device() does this dynamically with the adapter already known.
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*/
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struct i2c_board_info {
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char type[I2C_NAME_SIZE];
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unsigned short flags;
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unsigned short addr;
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void *platform_data;
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struct dev_archdata *archdata;
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struct device_node *of_node;
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struct fwnode_handle *fwnode;
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int irq;
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};
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/**
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* I2C_BOARD_INFO - macro used to list an i2c device and its address
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* @dev_type: identifies the device type
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* @dev_addr: the device's address on the bus.
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*
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* This macro initializes essential fields of a struct i2c_board_info,
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* declaring what has been provided on a particular board. Optional
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* fields (such as associated irq, or device-specific platform_data)
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* are provided using conventional syntax.
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*/
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#define I2C_BOARD_INFO(dev_type, dev_addr) \
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.type = dev_type, .addr = (dev_addr)
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#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
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/* Add-on boards should register/unregister their devices; e.g. a board
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* with integrated I2C, a config eeprom, sensors, and a codec that's
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* used in conjunction with the primary hardware.
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*/
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extern struct i2c_client *
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i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
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/* If you don't know the exact address of an I2C device, use this variant
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* instead, which can probe for device presence in a list of possible
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* addresses. The "probe" callback function is optional. If it is provided,
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* it must return 1 on successful probe, 0 otherwise. If it is not provided,
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* a default probing method is used.
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*/
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extern struct i2c_client *
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i2c_new_probed_device(struct i2c_adapter *adap,
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struct i2c_board_info *info,
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unsigned short const *addr_list,
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int (*probe)(struct i2c_adapter *, unsigned short addr));
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/* Common custom probe functions */
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extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
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/* For devices that use several addresses, use i2c_new_dummy() to make
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* client handles for the extra addresses.
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*/
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extern struct i2c_client *
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i2c_new_dummy(struct i2c_adapter *adap, u16 address);
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extern struct i2c_client *
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i2c_new_secondary_device(struct i2c_client *client,
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const char *name,
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u16 default_addr);
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extern void i2c_unregister_device(struct i2c_client *);
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#endif /* I2C */
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/* Mainboard arch_initcall() code should register all its I2C devices.
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* This is done at arch_initcall time, before declaring any i2c adapters.
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* Modules for add-on boards must use other calls.
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*/
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#ifdef CONFIG_I2C_BOARDINFO
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extern int
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i2c_register_board_info(int busnum, struct i2c_board_info const *info,
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unsigned n);
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#else
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static inline int
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i2c_register_board_info(int busnum, struct i2c_board_info const *info,
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unsigned n)
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{
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return 0;
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}
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#endif /* I2C_BOARDINFO */
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/**
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* struct i2c_algorithm - represent I2C transfer method
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* @master_xfer: Issue a set of i2c transactions to the given I2C adapter
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* defined by the msgs array, with num messages available to transfer via
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* the adapter specified by adap.
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* @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
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* is not present, then the bus layer will try and convert the SMBus calls
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* into I2C transfers instead.
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* @functionality: Return the flags that this algorithm/adapter pair supports
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* from the I2C_FUNC_* flags.
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* @reg_slave: Register given client to I2C slave mode of this adapter
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* @unreg_slave: Unregister given client from I2C slave mode of this adapter
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*
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* The following structs are for those who like to implement new bus drivers:
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* i2c_algorithm is the interface to a class of hardware solutions which can
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* be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
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* to name two of the most common.
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*
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* The return codes from the @master_xfer field should indicate the type of
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* error code that occurred during the transfer, as documented in the kernel
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* Documentation file Documentation/i2c/fault-codes.
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*/
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struct i2c_algorithm {
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/* If an adapter algorithm can't do I2C-level access, set master_xfer
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to NULL. If an adapter algorithm can do SMBus access, set
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smbus_xfer. If set to NULL, the SMBus protocol is simulated
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using common I2C messages */
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/* master_xfer should return the number of messages successfully
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processed, or a negative value on error */
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int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
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int num);
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int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
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unsigned short flags, char read_write,
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u8 command, int size, union i2c_smbus_data *data);
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/* To determine what the adapter supports */
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u32 (*functionality) (struct i2c_adapter *);
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#if IS_ENABLED(CONFIG_I2C_SLAVE)
|
|
int (*reg_slave)(struct i2c_client *client);
|
|
int (*unreg_slave)(struct i2c_client *client);
|
|
#endif
|
|
};
|
|
|
|
/**
|
|
* struct i2c_lock_operations - represent I2C locking operations
|
|
* @lock_bus: Get exclusive access to an I2C bus segment
|
|
* @trylock_bus: Try to get exclusive access to an I2C bus segment
|
|
* @unlock_bus: Release exclusive access to an I2C bus segment
|
|
*
|
|
* The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
|
|
*/
|
|
struct i2c_lock_operations {
|
|
void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
|
|
int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
|
|
void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
|
|
};
|
|
|
|
/**
|
|
* struct i2c_timings - I2C timing information
|
|
* @bus_freq_hz: the bus frequency in Hz
|
|
* @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
|
|
* @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
|
|
* @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
|
|
* @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
|
|
*/
|
|
struct i2c_timings {
|
|
u32 bus_freq_hz;
|
|
u32 scl_rise_ns;
|
|
u32 scl_fall_ns;
|
|
u32 scl_int_delay_ns;
|
|
u32 sda_fall_ns;
|
|
};
|
|
|
|
/**
|
|
* struct i2c_bus_recovery_info - I2C bus recovery information
|
|
* @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
|
|
* i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
|
|
* @get_scl: This gets current value of SCL line. Mandatory for generic SCL
|
|
* recovery. Used internally for generic GPIO recovery.
|
|
* @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
|
|
* internally for generic GPIO recovery.
|
|
* @get_sda: This gets current value of SDA line. Optional for generic SCL
|
|
* recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
|
|
* recovery.
|
|
* @prepare_recovery: This will be called before starting recovery. Platform may
|
|
* configure padmux here for SDA/SCL line or something else they want.
|
|
* @unprepare_recovery: This will be called after completing recovery. Platform
|
|
* may configure padmux here for SDA/SCL line or something else they want.
|
|
* @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
|
|
* @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
|
|
*/
|
|
struct i2c_bus_recovery_info {
|
|
int (*recover_bus)(struct i2c_adapter *);
|
|
|
|
int (*get_scl)(struct i2c_adapter *);
|
|
void (*set_scl)(struct i2c_adapter *, int val);
|
|
int (*get_sda)(struct i2c_adapter *);
|
|
|
|
void (*prepare_recovery)(struct i2c_adapter *);
|
|
void (*unprepare_recovery)(struct i2c_adapter *);
|
|
|
|
/* gpio recovery */
|
|
int scl_gpio;
|
|
int sda_gpio;
|
|
};
|
|
|
|
int i2c_recover_bus(struct i2c_adapter *adap);
|
|
|
|
/* Generic recovery routines */
|
|
int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
|
|
int i2c_generic_scl_recovery(struct i2c_adapter *adap);
|
|
|
|
/**
|
|
* struct i2c_adapter_quirks - describe flaws of an i2c adapter
|
|
* @flags: see I2C_AQ_* for possible flags and read below
|
|
* @max_num_msgs: maximum number of messages per transfer
|
|
* @max_write_len: maximum length of a write message
|
|
* @max_read_len: maximum length of a read message
|
|
* @max_comb_1st_msg_len: maximum length of the first msg in a combined message
|
|
* @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
|
|
*
|
|
* Note about combined messages: Some I2C controllers can only send one message
|
|
* per transfer, plus something called combined message or write-then-read.
|
|
* This is (usually) a small write message followed by a read message and
|
|
* barely enough to access register based devices like EEPROMs. There is a flag
|
|
* to support this mode. It implies max_num_msg = 2 and does the length checks
|
|
* with max_comb_*_len because combined message mode usually has its own
|
|
* limitations. Because of HW implementations, some controllers can actually do
|
|
* write-then-anything or other variants. To support that, write-then-read has
|
|
* been broken out into smaller bits like write-first and read-second which can
|
|
* be combined as needed.
|
|
*/
|
|
|
|
struct i2c_adapter_quirks {
|
|
u64 flags;
|
|
int max_num_msgs;
|
|
u16 max_write_len;
|
|
u16 max_read_len;
|
|
u16 max_comb_1st_msg_len;
|
|
u16 max_comb_2nd_msg_len;
|
|
};
|
|
|
|
/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
|
|
#define I2C_AQ_COMB BIT(0)
|
|
/* first combined message must be write */
|
|
#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
|
|
/* second combined message must be read */
|
|
#define I2C_AQ_COMB_READ_SECOND BIT(2)
|
|
/* both combined messages must have the same target address */
|
|
#define I2C_AQ_COMB_SAME_ADDR BIT(3)
|
|
/* convenience macro for typical write-then read case */
|
|
#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
|
|
I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
|
|
/* clock stretching is not supported */
|
|
#define I2C_AQ_NO_CLK_STRETCH BIT(4)
|
|
|
|
/*
|
|
* i2c_adapter is the structure used to identify a physical i2c bus along
|
|
* with the access algorithms necessary to access it.
|
|
*/
|
|
struct i2c_adapter {
|
|
struct module *owner;
|
|
unsigned int class; /* classes to allow probing for */
|
|
const struct i2c_algorithm *algo; /* the algorithm to access the bus */
|
|
void *algo_data;
|
|
|
|
/* data fields that are valid for all devices */
|
|
const struct i2c_lock_operations *lock_ops;
|
|
struct rt_mutex bus_lock;
|
|
struct rt_mutex mux_lock;
|
|
|
|
int timeout; /* in jiffies */
|
|
int retries;
|
|
struct device dev; /* the adapter device */
|
|
|
|
bool atomic_xfer_only;
|
|
bool cancel_xfer_on_shutdown;
|
|
|
|
int nr;
|
|
char name[48];
|
|
struct completion dev_released;
|
|
|
|
struct mutex userspace_clients_lock;
|
|
struct list_head userspace_clients;
|
|
|
|
struct i2c_bus_recovery_info *bus_recovery_info;
|
|
const struct i2c_adapter_quirks *quirks;
|
|
unsigned long bus_clk_rate;
|
|
bool (*is_bus_clk_rate_supported)(void *data,
|
|
unsigned long bus_clk_rate);
|
|
};
|
|
#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
|
|
|
|
static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
|
|
{
|
|
return dev_get_drvdata(&dev->dev);
|
|
}
|
|
|
|
static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
|
|
{
|
|
dev_set_drvdata(&dev->dev, data);
|
|
}
|
|
|
|
static inline struct i2c_adapter *
|
|
i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
|
|
{
|
|
#if IS_ENABLED(CONFIG_I2C_MUX)
|
|
struct device *parent = NULL;
|
|
|
|
if (adapter)
|
|
parent = adapter->dev.parent;
|
|
|
|
if (parent != NULL && parent->type == &i2c_adapter_type)
|
|
return to_i2c_adapter(parent);
|
|
else
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
|
|
|
|
/* Adapter locking functions, exported for shared pin cases */
|
|
#define I2C_LOCK_ROOT_ADAPTER BIT(0)
|
|
#define I2C_LOCK_SEGMENT BIT(1)
|
|
|
|
/**
|
|
* i2c_lock_bus - Get exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
|
|
* locks only this branch in the adapter tree
|
|
*/
|
|
static inline void
|
|
i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
|
|
{
|
|
adapter->lock_ops->lock_bus(adapter, flags);
|
|
}
|
|
|
|
/**
|
|
* i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
|
|
* I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
|
|
*
|
|
* Return: true if the I2C bus segment is locked, false otherwise
|
|
*/
|
|
static inline int
|
|
i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
|
|
{
|
|
return adapter->lock_ops->trylock_bus(adapter, flags);
|
|
}
|
|
|
|
/**
|
|
* i2c_unlock_bus - Release exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
|
|
* unlocks only this branch in the adapter tree
|
|
*/
|
|
static inline void
|
|
i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
|
|
{
|
|
adapter->lock_ops->unlock_bus(adapter, flags);
|
|
}
|
|
|
|
static inline void
|
|
i2c_lock_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
|
|
}
|
|
|
|
static inline void
|
|
i2c_unlock_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
|
|
}
|
|
|
|
void i2c_shutdown_adapter(struct i2c_adapter *adapter);
|
|
void i2c_shutdown_clear_adapter(struct i2c_adapter *adapter);
|
|
|
|
/*flags for the client struct: */
|
|
#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
|
|
#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
|
|
/* Must equal I2C_M_TEN below */
|
|
#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
|
|
#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
|
|
#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
|
|
/* Must match I2C_M_STOP|IGNORE_NAK */
|
|
|
|
/* i2c adapter classes (bitmask) */
|
|
#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
|
|
#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
|
|
#define I2C_CLASS_SPD (1<<7) /* Memory modules */
|
|
#define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
|
|
|
|
/* Internal numbers to terminate lists */
|
|
#define I2C_CLIENT_END 0xfffeU
|
|
|
|
/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
|
|
#define I2C_ADDRS(addr, addrs...) \
|
|
((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
|
|
|
|
|
|
/* ----- functions exported by i2c.o */
|
|
|
|
/* administration...
|
|
*/
|
|
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
|
|
extern int i2c_add_adapter(struct i2c_adapter *);
|
|
extern void i2c_del_adapter(struct i2c_adapter *);
|
|
extern int i2c_add_numbered_adapter(struct i2c_adapter *);
|
|
|
|
extern int i2c_register_driver(struct module *, struct i2c_driver *);
|
|
extern void i2c_del_driver(struct i2c_driver *);
|
|
|
|
/* use a define to avoid include chaining to get THIS_MODULE */
|
|
#define i2c_add_driver(driver) \
|
|
i2c_register_driver(THIS_MODULE, driver)
|
|
|
|
extern struct i2c_client *i2c_use_client(struct i2c_client *client);
|
|
extern void i2c_release_client(struct i2c_client *client);
|
|
|
|
/* call the i2c_client->command() of all attached clients with
|
|
* the given arguments */
|
|
extern void i2c_clients_command(struct i2c_adapter *adap,
|
|
unsigned int cmd, void *arg);
|
|
|
|
extern struct i2c_adapter *i2c_get_adapter(int nr);
|
|
extern void i2c_put_adapter(struct i2c_adapter *adap);
|
|
extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
|
|
|
|
void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
|
|
|
|
/* Return the functionality mask */
|
|
static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
|
|
{
|
|
return adap->algo->functionality(adap);
|
|
}
|
|
|
|
/* Return 1 if adapter supports everything we need, 0 if not. */
|
|
static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
|
|
{
|
|
return (func & i2c_get_functionality(adap)) == func;
|
|
}
|
|
|
|
/**
|
|
* i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
|
|
* @adap: i2c adapter
|
|
* @quirks: quirk flags
|
|
*
|
|
* Return: true if the adapter has all the specified quirk flags, false if not
|
|
*/
|
|
static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
|
|
{
|
|
if (!adap->quirks)
|
|
return false;
|
|
return (adap->quirks->flags & quirks) == quirks;
|
|
}
|
|
|
|
/* Return the adapter number for a specific adapter */
|
|
static inline int i2c_adapter_id(struct i2c_adapter *adap)
|
|
{
|
|
return adap->nr;
|
|
}
|
|
|
|
static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
|
|
{
|
|
return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
|
|
}
|
|
|
|
/**
|
|
* module_i2c_driver() - Helper macro for registering a modular I2C driver
|
|
* @__i2c_driver: i2c_driver struct
|
|
*
|
|
* Helper macro for I2C drivers which do not do anything special in module
|
|
* init/exit. This eliminates a lot of boilerplate. Each module may only
|
|
* use this macro once, and calling it replaces module_init() and module_exit()
|
|
*/
|
|
#define module_i2c_driver(__i2c_driver) \
|
|
module_driver(__i2c_driver, i2c_add_driver, \
|
|
i2c_del_driver)
|
|
|
|
/**
|
|
* builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
|
|
* @__i2c_driver: i2c_driver struct
|
|
*
|
|
* Helper macro for I2C drivers which do not do anything special in their
|
|
* init. This eliminates a lot of boilerplate. Each driver may only
|
|
* use this macro once, and calling it replaces device_initcall().
|
|
*/
|
|
#define builtin_i2c_driver(__i2c_driver) \
|
|
builtin_driver(__i2c_driver, i2c_add_driver)
|
|
|
|
#endif /* I2C */
|
|
|
|
#if IS_ENABLED(CONFIG_OF)
|
|
/* must call put_device() when done with returned i2c_client device */
|
|
extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
|
|
|
|
/* must call put_device() when done with returned i2c_adapter device */
|
|
extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
|
|
|
|
/* must call i2c_put_adapter() when done with returned i2c_adapter device */
|
|
struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
|
|
|
|
#else
|
|
|
|
static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_OF */
|
|
|
|
#if IS_ENABLED(CONFIG_ACPI)
|
|
u32 i2c_acpi_find_bus_speed(struct device *dev);
|
|
#else
|
|
static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_ACPI */
|
|
|
|
#endif /* _LINUX_I2C_H */
|