📄 i2c.h
字号:
/* ------------------------------------------------------------------------- */
/* */
/* 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Ky鰏ti M鋖kki <kmalkki@cc.hut.fi> and
Frodo Looijaard <frodol@dds.nl> */
/* $Id: i2c.h,v 2.0 2006/09/22 05:27:59 lxw Exp $ */
#ifndef _LINUX_I2C_H
#define _LINUX_I2C_H
#include <linux/module.h>
#include <linux/types.h>
#include <linux/i2c-id.h>
#include <linux/device.h> /* for struct device */
#include <asm/semaphore.h>
/* --- General options ------------------------------------------------ */
struct i2c_msg;
struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
struct i2c_client_address_data;
union i2c_smbus_data;
/*
* 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.
*/
extern int i2c_master_send(struct i2c_client *,const char* ,int);
extern int i2c_master_recv(struct i2c_client *,char* ,int);
/* Transfer num messages.
*/
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
/*
* Some adapter types (i.e. PCF 8584 based ones) may support slave behaviuor.
* This is not tested/implemented yet and will change in the future.
*/
extern int i2c_slave_send(struct i2c_client *,char*,int);
extern int i2c_slave_recv(struct i2c_client *,char*,int);
/* 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. */
extern s32 i2c_smbus_xfer (struct i2c_adapter * adapter, u16 addr,
unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data * data);
/* Now follow the 'nice' access routines. These also document the calling
conventions of smbus_access. */
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte(struct i2c_client * client);
extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command);
extern s32 i2c_smbus_write_byte_data(struct i2c_client * client,
u8 command, u8 value);
extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
u8 command, u16 value);
/* Returns the number of bytes transferred */
extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
u8 command, u8 length,
u8 *values);
extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client * client,
u8 command, u8 *values);
/*
* A driver is capable of handling one or more physical devices present on
* I2C adapters. This information is used to inform the driver of adapter
* events.
*/
struct i2c_driver {
struct module *owner;
char name[32];
int id;
unsigned int class;
unsigned int flags; /* div., see below */
/* Notifies the driver that a new bus has appeared. This routine
* can be used by the driver to test if the bus meets its conditions
* & seek for the presence of the chip(s) it supports. If found, it
* registers the client(s) that are on the bus to the i2c admin. via
* i2c_attach_client.
*/
int (*attach_adapter)(struct i2c_adapter *);
int (*detach_adapter)(struct i2c_adapter *);
/* tells the driver that a client is about to be deleted & gives it
* the chance to remove its private data. Also, if the client struct
* has been dynamically allocated by the driver in the function above,
* it must be freed here.
*/
int (*detach_client)(struct i2c_client *);
/* 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;
struct list_head list;
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
#define I2C_NAME_SIZE 50
/*
* i2c_client identifies a single device (i.e. chip) that is connected to an
* i2c bus. The behaviour is defined by the routines of the driver. This
* function is mainly used for lookup & other admin. functions.
*/
struct i2c_client {
unsigned int flags; /* div., see below */
unsigned int addr; /* chip address - NOTE: 7bit */
/* addresses are stored in the */
/* _LOWER_ 7 bits of this char */
/* addr: unsigned int to make lm_sensors i2c-isa adapter work
more cleanly. It does not take any more memory space, due to
alignment considerations */
struct i2c_adapter *adapter; /* the adapter we sit on */
struct i2c_driver *driver; /* and our access routines */
int usage_count; /* How many accesses currently */
/* to the client */
struct device dev; /* the device structure */
struct list_head list;
char name[I2C_NAME_SIZE];
struct completion released;
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
static inline void *i2c_get_clientdata (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);
}
#define I2C_DEVNAME(str) .name = str
static inline char *i2c_clientname(struct i2c_client *c)
{
return &c->name[0];
}
/*
* 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.
*/
struct i2c_algorithm {
char name[32]; /* textual description */
unsigned int id;
/* 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 */
int (*master_xfer)(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);
/* --- these optional/future use for some adapter types.*/
int (*slave_send)(struct i2c_adapter *,char*,int);
int (*slave_recv)(struct i2c_adapter *,char*,int);
/* --- ioctl like call to set div. parameters. */
int (*algo_control)(struct i2c_adapter *, unsigned int, unsigned long);
/* To determine what the adapter supports */
u32 (*functionality) (struct i2c_adapter *);
};
/*
* 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 id;/* == is algo->id | hwdep.struct->id, */
/* for registered values see below */
unsigned int class;
struct i2c_algorithm *algo;/* the algorithm to access the bus */
void *algo_data;
/* --- administration stuff. */
int (*client_register)(struct i2c_client *);
int (*client_unregister)(struct i2c_client *);
/* data fields that are valid for all devices */
struct semaphore bus_lock;
struct semaphore clist_lock;
int timeout;
int retries;
struct device dev; /* the adapter device */
struct class_device class_dev; /* the class device */
#ifdef CONFIG_PROC_FS
/* No need to set this when you initialize the adapter */
int inode;
#endif /* def CONFIG_PROC_FS */
int nr;
struct list_head clients;
struct list_head list;
char name[I2C_NAME_SIZE];
struct completion dev_released;
struct completion class_dev_released;
};
#define dev_to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
#define class_dev_to_i2c_adapter(d) container_of(d, struct i2c_adapter, class_dev)
static inline void *i2c_get_adapdata (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);
}
/*flags for the driver struct: */
#define I2C_DF_NOTIFY 0x01 /* notify on bus (de/a)ttaches */
#if 0
/* this flag is gone -- there is a (optional) driver->detach_adapter
* callback now which can be used instead */
# define I2C_DF_DUMMY 0x02
#endif
/*flags for the client struct: */
#define I2C_CLIENT_ALLOW_USE 0x01 /* Client allows access */
#define I2C_CLIENT_ALLOW_MULTIPLE_USE 0x02 /* Allow multiple access-locks */
/* on an i2c_client */
#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 */
/* i2c adapter classes (bitmask) */
#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
#define I2C_CLASS_TV_ANALOG (1<<1) /* bttv + friends */
#define I2C_CLASS_TV_DIGITAL (1<<2) /* dvb cards */
#define I2C_CLASS_DDC (1<<3) /* i2c-matroxfb ? */
#define I2C_CLASS_CAM_ANALOG (1<<4) /* camera with analog CCD */
#define I2C_CLASS_CAM_DIGITAL (1<<5) /* most webcams */
#define I2C_CLASS_SOUND (1<<6) /* sound devices */
#define I2C_CLASS_ALL (UINT_MAX) /* all of the above */
/* i2c_client_address_data is the struct for holding default client
* addresses for a driver and for the parameters supplied on the
* command line
*/
struct i2c_client_address_data {
unsigned short *normal_i2c;
unsigned short *normal_i2c_range;
unsigned short *probe;
unsigned short *probe_range;
unsigned short *ignore;
unsigned short *ignore_range;
unsigned short *force;
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -