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linux-sg2042/include/linux/i2c.h

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/* ------------------------------------------------------------------------- */
/* */
/* i2c.h - definitions for the i2c-bus interface */
/* */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 1995-2000 Simon G. Vogl
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301 USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
Frodo Looijaard <frodol@dds.nl> */
#ifndef _LINUX_I2C_H
#define _LINUX_I2C_H
#include <linux/mod_devicetable.h>
#include <linux/device.h> /* for struct device */
#include <linux/sched.h> /* for completion */
#include <linux/mutex.h>
#include <linux/rtmutex.h>
#include <linux/irqdomain.h> /* for Host Notify IRQ */
#include <linux/of.h> /* for struct device_node */
#include <linux/swab.h> /* for swab16 */
#include <uapi/linux/i2c.h>
extern struct bus_type i2c_bus_type;
extern struct device_type i2c_adapter_type;
extern struct device_type i2c_client_type;
/* --- General options ------------------------------------------------ */
struct i2c_msg;
struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
struct i2c_device_identity;
union i2c_smbus_data;
struct i2c_board_info;
enum i2c_slave_event;
typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *);
struct module;
struct property_entry;
#if IS_ENABLED(CONFIG_I2C)
/*
* The master routines are the ones normally used to transmit data to devices
* on a bus (or read from them). Apart from two basic transfer functions to
* transmit one message at a time, a more complex version can be used to
* transmit an arbitrary number of messages without interruption.
* @count must be be less than 64k since msg.len is u16.
*/
extern int i2c_transfer_buffer_flags(const struct i2c_client *client,
char *buf, int count, u16 flags);
/**
* i2c_master_recv - issue a single I2C message in master receive mode
* @client: Handle to slave device
* @buf: Where to store data read from slave
* @count: How many bytes to read, must be less than 64k since msg.len is u16
*
* Returns negative errno, or else the number of bytes read.
*/
static inline int i2c_master_recv(const struct i2c_client *client,
char *buf, int count)
{
return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
};
/**
* i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
* using a DMA safe buffer
* @client: Handle to slave device
* @buf: Where to store data read from slave, must be safe to use with DMA
* @count: How many bytes to read, must be less than 64k since msg.len is u16
*
* Returns negative errno, or else the number of bytes read.
*/
static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
char *buf, int count)
{
return i2c_transfer_buffer_flags(client, buf, count,
I2C_M_RD | I2C_M_DMA_SAFE);
};
/**
* i2c_master_send - issue a single I2C message in master transmit mode
* @client: Handle to slave device
* @buf: Data that will be written to the slave
* @count: How many bytes to write, must be less than 64k since msg.len is u16
*
* Returns negative errno, or else the number of bytes written.
*/
static inline int i2c_master_send(const struct i2c_client *client,
const char *buf, int count)
{
return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
};
/**
* i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
* using a DMA safe buffer
* @client: Handle to slave device
* @buf: Data that will be written to the slave, must be safe to use with DMA
* @count: How many bytes to write, must be less than 64k since msg.len is u16
*
* Returns negative errno, or else the number of bytes written.
*/
static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
const char *buf, int count)
{
return i2c_transfer_buffer_flags(client, (char *)buf, count,
I2C_M_DMA_SAFE);
};
/* Transfer num messages.
*/
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num);
/* Unlocked flavor */
extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num);
/* This is the very generalized SMBus access routine. You probably do not
want to use this, though; one of the functions below may be much easier,
and probably just as fast.
Note that we use i2c_adapter here, because you do not need a specific
smbus adapter to call this function. */
s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
unsigned short flags, char read_write, u8 command,
int protocol, union i2c_smbus_data *data);
/* Unlocked flavor */
s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
unsigned short flags, char read_write, u8 command,
int protocol, union i2c_smbus_data *data);
/* Now follow the 'nice' access routines. These also document the calling
conventions of i2c_smbus_xfer. */
extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
u8 command);
extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
u8 command, u8 value);
extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
u8 command);
extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
u8 command, u16 value);
static inline s32
i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
{
s32 value = i2c_smbus_read_word_data(client, command);
return (value < 0) ? value : swab16(value);
}
static inline s32
i2c_smbus_write_word_swapped(const struct i2c_client *client,
u8 command, u16 value)
{
return i2c_smbus_write_word_data(client, command, swab16(value));
}
/* Returns the number of read bytes */
extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
u8 command, u8 *values);
extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
u8 command, u8 length, const u8 *values);
/* Returns the number of read bytes */
extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
u8 command, u8 length, u8 *values);
extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
u8 command, u8 length,
const u8 *values);
extern s32
i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
u8 command, u8 length, u8 *values);
int i2c_get_device_id(const struct i2c_client *client,
struct i2c_device_identity *id);
#endif /* I2C */
/**
* struct i2c_device_identity - i2c client device identification
* @manufacturer_id: 0 - 4095, database maintained by NXP
* @part_id: 0 - 511, according to manufacturer
* @die_revision: 0 - 7, according to manufacturer
*/
struct i2c_device_identity {
u16 manufacturer_id;
#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
#define I2C_DEVICE_ID_ANALOG_DEVICES 5
#define I2C_DEVICE_ID_STMICROELECTRONICS 6
#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
#define I2C_DEVICE_ID_FLIR 11
#define I2C_DEVICE_ID_O2MICRO 12
#define I2C_DEVICE_ID_ATMEL 13
#define I2C_DEVICE_ID_NONE 0xffff
u16 part_id;
u8 die_revision;
};
enum i2c_alert_protocol {
I2C_PROTOCOL_SMBUS_ALERT,
I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
};
/**
* struct i2c_driver - represent an I2C device driver
* @class: What kind of i2c device we instantiate (for detect)
* @probe: Callback for device binding - soon to be deprecated
* @probe_new: New callback for device binding
* @remove: Callback for device unbinding
* @shutdown: Callback for device shutdown
* @alert: Alert callback, for example for the SMBus alert protocol
* @command: Callback for bus-wide signaling (optional)
* @driver: Device driver model driver
* @id_table: List of I2C devices supported by this driver
* @detect: Callback for device detection
* @address_list: The I2C addresses to probe (for detect)
* @clients: List of detected clients we created (for i2c-core use only)
* @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
*
* The driver.owner field should be set to the module owner of this driver.
* The driver.name field should be set to the name of this driver.
*
* For automatic device detection, both @detect and @address_list must
* be defined. @class should also be set, otherwise only devices forced
* with module parameters will be created. The detect function must
* fill at least the name field of the i2c_board_info structure it is
* handed upon successful detection, and possibly also the flags field.
*
* If @detect is missing, the driver will still work fine for enumerated
* devices. Detected devices simply won't be supported. This is expected
* for the many I2C/SMBus devices which can't be detected reliably, and
* the ones which can always be enumerated in practice.
*
* The i2c_client structure which is handed to the @detect callback is
* not a real i2c_client. It is initialized just enough so that you can
* call i2c_smbus_read_byte_data and friends on it. Don't do anything
* else with it. In particular, calling dev_dbg and friends on it is
* not allowed.
*/
struct i2c_driver {
unsigned int class;
/* Standard driver model interfaces */
int (*probe)(struct i2c_client *, const struct i2c_device_id *);
int (*remove)(struct i2c_client *);
/* New driver model interface to aid the seamless removal of the
* current probe()'s, more commonly unused than used second parameter.
*/
int (*probe_new)(struct i2c_client *);
/* driver model interfaces that don't relate to enumeration */
void (*shutdown)(struct i2c_client *);
/* Alert callback, for example for the SMBus alert protocol.
* The format and meaning of the data value depends on the protocol.
* For the SMBus alert protocol, there is a single bit of data passed
* as the alert response's low bit ("event flag").
* For the SMBus Host Notify protocol, the data corresponds to the
* 16-bit payload data reported by the slave device acting as master.
*/
void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
unsigned int data);
/* a ioctl like command that can be used to perform specific functions
* with the device.
*/
int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
struct device_driver driver;
const struct i2c_device_id *id_table;
/* Device detection callback for automatic device creation */
int (*detect)(struct i2c_client *, struct i2c_board_info *);
const unsigned short *address_list;
struct list_head clients;
bool disable_i2c_core_irq_mapping;
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
/**
* struct i2c_client - represent an I2C slave device
* @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
* I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
* @addr: Address used on the I2C bus connected to the parent adapter.
* @name: Indicates the type of the device, usually a chip name that's
* generic enough to hide second-sourcing and compatible revisions.
* @adapter: manages the bus segment hosting this I2C device
* @dev: Driver model device node for the slave.
* @irq: indicates the IRQ generated by this device (if any)
* @detected: member of an i2c_driver.clients list or i2c-core's
* userspace_devices list
* @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
* calls it to pass on slave events to the slave driver.
*
* An i2c_client identifies a single device (i.e. chip) connected to an
* i2c bus. The behaviour exposed to Linux is defined by the driver
* managing the device.
*/
struct i2c_client {
unsigned short flags; /* div., see below */
unsigned short addr; /* chip address - NOTE: 7bit */
/* addresses are stored in the */
/* _LOWER_ 7 bits */
char name[I2C_NAME_SIZE];
struct i2c_adapter *adapter; /* the adapter we sit on */
struct device dev; /* the device structure */
int init_irq; /* irq set at initialization */
int irq; /* irq issued by device */
struct list_head detected;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
i2c_slave_cb_t slave_cb; /* callback for slave mode */
#endif
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
extern struct i2c_client *i2c_verify_client(struct device *dev);
extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
const struct i2c_client *client);
static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
{
struct device * const dev = container_of(kobj, struct device, kobj);
return to_i2c_client(dev);
}
static inline void *i2c_get_clientdata(const struct i2c_client *dev)
{
return dev_get_drvdata(&dev->dev);
}
static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
{
dev_set_drvdata(&dev->dev, data);
}
/* I2C slave support */
#if IS_ENABLED(CONFIG_I2C_SLAVE)
enum i2c_slave_event {
I2C_SLAVE_READ_REQUESTED,
I2C_SLAVE_WRITE_REQUESTED,
I2C_SLAVE_READ_PROCESSED,
I2C_SLAVE_WRITE_RECEIVED,
I2C_SLAVE_STOP,
};
extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
extern int i2c_slave_unregister(struct i2c_client *client);
extern bool i2c_detect_slave_mode(struct device *dev);
static inline int i2c_slave_event(struct i2c_client *client,
enum i2c_slave_event event, u8 *val)
{
return client->slave_cb(client, event, val);
}
#else
static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
#endif
/**
* struct i2c_board_info - template for device creation
* @type: chip type, to initialize i2c_client.name
* @flags: to initialize i2c_client.flags
* @addr: stored in i2c_client.addr
* @dev_name: Overrides the default <busnr>-<addr> dev_name if set
* @platform_data: stored in i2c_client.dev.platform_data
* @of_node: pointer to OpenFirmware device node
* @fwnode: device node supplied by the platform firmware
* @properties: additional device properties for the device
* @resources: resources associated with the device
* @num_resources: number of resources in the @resources array
* @irq: stored in i2c_client.irq
*
* I2C doesn't actually support hardware probing, although controllers and
* devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
* a device at a given address. Drivers commonly need more information than
* that, such as chip type, configuration, associated IRQ, and so on.
*
* i2c_board_info is used to build tables of information listing I2C devices
* that are present. This information is used to grow the driver model tree.
* For mainboards this is done statically using i2c_register_board_info();
* bus numbers identify adapters that aren't yet available. For add-on boards,
* i2c_new_device() does this dynamically with the adapter already known.
*/
struct i2c_board_info {
char type[I2C_NAME_SIZE];
unsigned short flags;
unsigned short addr;
const char *dev_name;
void *platform_data;
struct device_node *of_node;
struct fwnode_handle *fwnode;
const struct property_entry *properties;
const struct resource *resources;
unsigned int num_resources;
int irq;
};
/**
* I2C_BOARD_INFO - macro used to list an i2c device and its address
* @dev_type: identifies the device type
* @dev_addr: the device's address on the bus.
*
* This macro initializes essential fields of a struct i2c_board_info,
* declaring what has been provided on a particular board. Optional
* fields (such as associated irq, or device-specific platform_data)
* are provided using conventional syntax.
*/
#define I2C_BOARD_INFO(dev_type, dev_addr) \
.type = dev_type, .addr = (dev_addr)
#if IS_ENABLED(CONFIG_I2C)
/* Add-on boards should register/unregister their devices; e.g. a board
* with integrated I2C, a config eeprom, sensors, and a codec that's
* used in conjunction with the primary hardware.
*/
extern struct i2c_client *
i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
/* If you don't know the exact address of an I2C device, use this variant
* instead, which can probe for device presence in a list of possible
* addresses. The "probe" callback function is optional. If it is provided,
* it must return 1 on successful probe, 0 otherwise. If it is not provided,
* a default probing method is used.
*/
extern struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
struct i2c_board_info *info,
unsigned short const *addr_list,
int (*probe)(struct i2c_adapter *, unsigned short addr));
/* Common custom probe functions */
extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
/* For devices that use several addresses, use i2c_new_dummy() to make
* client handles for the extra addresses.
*/
extern struct i2c_client *
i2c_new_dummy(struct i2c_adapter *adap, u16 address);
extern struct i2c_client *
devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
extern struct i2c_client *
i2c_new_secondary_device(struct i2c_client *client,
const char *name,
u16 default_addr);
extern void i2c_unregister_device(struct i2c_client *);
#endif /* I2C */
/* Mainboard arch_initcall() code should register all its I2C devices.
* This is done at arch_initcall time, before declaring any i2c adapters.
* Modules for add-on boards must use other calls.
*/
#ifdef CONFIG_I2C_BOARDINFO
extern int
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
unsigned n);
#else
static inline int
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
unsigned n)
{
return 0;
}
#endif /* I2C_BOARDINFO */
/**
* struct i2c_algorithm - represent I2C transfer method
* @master_xfer: Issue a set of i2c transactions to the given I2C adapter
* defined by the msgs array, with num messages available to transfer via
* the adapter specified by adap.
* @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
* so e.g. PMICs can be accessed very late before shutdown. Optional.
* @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
* is not present, then the bus layer will try and convert the SMBus calls
* into I2C transfers instead.
* @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
* so e.g. PMICs can be accessed very late before shutdown. Optional.
* @functionality: Return the flags that this algorithm/adapter pair supports
* from the I2C_FUNC_* flags.
* @reg_slave: Register given client to I2C slave mode of this adapter
* @unreg_slave: Unregister given client from I2C slave mode of this adapter
*
* The following structs are for those who like to implement new bus drivers:
* i2c_algorithm is the interface to a class of hardware solutions which can
* be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
* to name two of the most common.
*
* The return codes from the @master_xfer{_atomic} fields should indicate the
* type of error code that occurred during the transfer, as documented in the
* Kernel Documentation file Documentation/i2c/fault-codes.
*/
struct i2c_algorithm {
/*
* If an adapter algorithm can't do I2C-level access, set master_xfer
* to NULL. If an adapter algorithm can do SMBus access, set
* smbus_xfer. If set to NULL, the SMBus protocol is simulated
* using common I2C messages.
*
* master_xfer should return the number of messages successfully
* processed, or a negative value on error
*/
int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num);
int (*master_xfer_atomic)(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num);
int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data);
int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data);
/* To determine what the adapter supports */
u32 (*functionality)(struct i2c_adapter *adap);
#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
* @sda_hold_ns: time IP core additionally needs to hold SDA in ns
*/
struct i2c_timings {
u32 bus_freq_hz;
u32 scl_rise_ns;
u32 scl_fall_ns;
u32 scl_int_delay_ns;
u32 sda_fall_ns;
u32 sda_hold_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().
* @get_scl: This gets current value of SCL line. Mandatory for generic SCL
* recovery. Populated internally for generic GPIO recovery.
* @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
* Populated internally for generic GPIO recovery.
* @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
* for generic SCL recovery. Populated internally, if sda_gpio is a valid
* GPIO, for generic GPIO recovery.
* @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
* generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
* for generic GPIO recovery.
* @get_bus_free: Returns the bus free state as seen from the IP core in case it
* has a more complex internal logic than just reading SDA. Optional.
* @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_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
* @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
*/
struct i2c_bus_recovery_info {
int (*recover_bus)(struct i2c_adapter *adap);
int (*get_scl)(struct i2c_adapter *adap);
void (*set_scl)(struct i2c_adapter *adap, int val);
int (*get_sda)(struct i2c_adapter *adap);
void (*set_sda)(struct i2c_adapter *adap, int val);
int (*get_bus_free)(struct i2c_adapter *adap);
void (*prepare_recovery)(struct i2c_adapter *adap);
void (*unprepare_recovery)(struct i2c_adapter *adap);
/* gpio recovery */
struct gpio_desc *scl_gpiod;
struct gpio_desc *sda_gpiod;
};
int i2c_recover_bus(struct i2c_adapter *adap);
/* Generic recovery routines */
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)
/* message cannot have length of 0 */
#define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
/*
* 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 */
unsigned long locked_flags; /* owned by the I2C core */
#define I2C_ALF_IS_SUSPENDED 0
#define I2C_ALF_SUSPEND_REPORTED 1
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;
struct irq_domain *host_notify_domain;
};
#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 = 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);
}
/**
* i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
* @adap: Adapter to mark as suspended
*
* When using this helper to mark an adapter as suspended, the core will reject
* further transfers to this adapter. The usage of this helper is optional but
* recommended for devices having distinct handlers for system suspend and
* runtime suspend. More complex devices are free to implement custom solutions
* to reject transfers when suspended.
*/
static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
{
i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
}
/**
* i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
* @adap: Adapter to mark as resumed
*
* When using this helper to mark an adapter as resumed, the core will allow
* further transfers to this adapter. See also further notes to
* @i2c_mark_adapter_suspended().
*/
static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
{
i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
i2c_unlock_bus(adap, I2C_LOCK_ROOT_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_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
#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 */
/* Warn users that the adapter doesn't support classes anymore */
#define I2C_CLASS_DEPRECATED (1<<8)
/* 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 IS_ENABLED(CONFIG_I2C)
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);
}
u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
/**
* 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);
extern const struct of_device_id
*i2c_of_match_device(const struct of_device_id *matches,
struct i2c_client *client);
int of_i2c_get_board_info(struct device *dev, struct device_node *node,
struct i2c_board_info *info);
#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;
}
static inline const struct of_device_id
*i2c_of_match_device(const struct of_device_id *matches,
struct i2c_client *client)
{
return NULL;
}
static inline int of_i2c_get_board_info(struct device *dev,
struct device_node *node,
struct i2c_board_info *info)
{
return -ENOTSUPP;
}
#endif /* CONFIG_OF */
struct acpi_resource;
struct acpi_resource_i2c_serialbus;
#if IS_ENABLED(CONFIG_ACPI)
bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
struct acpi_resource_i2c_serialbus **i2c);
u32 i2c_acpi_find_bus_speed(struct device *dev);
struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
struct i2c_board_info *info);
#else
static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
struct acpi_resource_i2c_serialbus **i2c)
{
return false;
}
static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
{
return 0;
}
static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
int index, struct i2c_board_info *info)
{
return NULL;
}
#endif /* CONFIG_ACPI */
#endif /* _LINUX_I2C_H */
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