#ifndef I2C_H#define I2C_H/* * linux i2c interface.  Works a little bit like the scsi subsystem. * There are: * *     i2c          the basic control module        (like scsi_mod) *     bus driver   a driver with a i2c bus         (hostadapter driver) *     chip driver  a driver for a chip connected *                  to a i2c bus                    (cdrom/hd driver) * * A device will be attached to one bus and one chip driver.  Every chip * driver gets a unique ID. * * A chip driver can provide a ioctl-like callback for the * communication with other parts of the kernel (not every i2c chip is * useful without other devices, a TV card tuner for example).  * * "i2c internal" parts of the structs: only the i2c module is allowed to * write to them, for others they are read-only. * */#include <linux/version.h>#define I2C_BUS_MAX       4    /* max # of bus drivers  */#define I2C_DRIVER_MAX    8    /* max # of chip drivers */#define I2C_DEVICE_MAX    8    /* max # if devices per bus/driver */struct i2c_bus;struct i2c_driver;struct i2c_device;#define I2C_DRIVERID_MSP3400    	 1#define I2C_DRIVERID_TUNER      	 2#define I2C_DRIVERID_VIDEOTEXT		 3#define I2C_DRIVERID_VIDEODECODER	 4#define I2C_DRIVERID_VIDEOENCODER	 5#define I2C_BUSID_BT848		1	/* I2C bus on a BT848 */#define I2C_BUSID_PARPORT	2	/* Bit banging on a parallel port */#define I2C_BUSID_BUZ		3#define I2C_BUSID_ZORAN		4#define I2C_BUSID_CYBER2000	5/* * struct for a driver for a i2c chip (tuner, soundprocessor, * videotext, ... ). * * a driver will register within the i2c module.  The i2c module will * callback the driver (i2c_attach) for every device it finds on a i2c * bus at the specified address.  If the driver decides to "accept" * the, device, it must return a struct i2c_device, and NULL * otherwise. * * i2c_detach = i2c_attach ** -1 *  * i2c_command will be used to pass commands to the driver in a * ioctl-line manner. * */struct i2c_driver {    char           name[32];         /* some useful label         */    int            id;               /* device type ID            */    unsigned char  addr_l, addr_h;   /* address range of the chip */    int (*attach)(struct i2c_device *device);    int (*detach)(struct i2c_device *device);    int (*command)(struct i2c_device *device,unsigned int cmd, void *arg);    /* i2c internal */    struct i2c_device   *devices[I2C_DEVICE_MAX];    int                 devcount;};/* * this holds the informations about a i2c bus available in the system. *  * a chip with a i2c bus interface (like bt848) registers the bus within * the i2c module. This struct provides functions to access the i2c bus. *  * One must hold the spinlock to access the i2c bus (XXX: is the irqsave * required? Maybe better use a semaphore?).  * [-AC-] having a spinlock_irqsave is only needed if we have drivers wishing *	  to bang their i2c bus from an interrupt. *  * attach/detach_inform is a callback to inform the bus driver about * attached chip drivers. * *//* needed: unsigned long flags */#if LINUX_VERSION_CODE >= 0x020100# if 0#  define LOCK_FLAGS unsigned long flags;#  define LOCK_I2C_BUS(bus)    spin_lock_irqsave(&(bus->bus_lock),flags);#  define UNLOCK_I2C_BUS(bus)  spin_unlock_irqrestore(&(bus->bus_lock),flags);# else#  define LOCK_FLAGS#  define LOCK_I2C_BUS(bus)    spin_lock(&(bus->bus_lock));#  define UNLOCK_I2C_BUS(bus)  spin_unlock(&(bus->bus_lock));# endif#else# define LOCK_FLAGS unsigned long flags;# define LOCK_I2C_BUS(bus)    { save_flags(flags); cli(); }# define UNLOCK_I2C_BUS(bus)  { restore_flags(flags);     }#endifstruct i2c_bus {	char  name[32];         /* some useful label */	int   id;	void  *data;            /* free for use by the bus driver */#if LINUX_VERSION_CODE >= 0x020100	spinlock_t bus_lock;#endif	/* attach/detach inform callbacks */	void    (*attach_inform)(struct i2c_bus *bus, int id);	void    (*detach_inform)(struct i2c_bus *bus, int id);	/* Software I2C */	void    (*i2c_setlines)(struct i2c_bus *bus, int ctrl, int data);	int     (*i2c_getdataline)(struct i2c_bus *bus);	/* Hardware I2C */	int     (*i2c_read)(struct i2c_bus *bus, unsigned char addr);	int     (*i2c_write)(struct i2c_bus *bus, unsigned char addr,			 unsigned char b1, unsigned char b2, int both);	/* internal data for i2c module */	struct i2c_device   *devices[I2C_DEVICE_MAX];	int                 devcount;};/* *	This holds per-device data for a i2c device */struct i2c_device {	char           name[32];         /* some useful label */	void           *data;            /* free for use by the chip driver */	unsigned char  addr;             /* chip addr */	/* i2c internal */	struct i2c_bus     *bus;	struct i2c_driver  *driver;};/* ------------------------------------------------------------------- *//* i2c module functions                                                *//* register/unregister a i2c bus */int i2c_register_bus(struct i2c_bus *bus);int i2c_unregister_bus(struct i2c_bus *bus);/* register/unregister a chip driver */int i2c_register_driver(struct i2c_driver *driver);int i2c_unregister_driver(struct i2c_driver *driver);/* send a command to a chip using the ioctl-like callback interface */int i2c_control_device(struct i2c_bus *bus, int id,		       unsigned int cmd, void *arg);/* i2c bus access functions */void    i2c_start(struct i2c_bus *bus);void    i2c_stop(struct i2c_bus *bus);void    i2c_one(struct i2c_bus *bus);void    i2c_zero(struct i2c_bus *bus);int     i2c_ack(struct i2c_bus *bus);int     i2c_sendbyte(struct i2c_bus *bus,unsigned char data,int wait_for_ack);unsigned char i2c_readbyte(struct i2c_bus *bus,int last);/* i2c (maybe) hardware functions */int     i2c_read(struct i2c_bus *bus, unsigned char addr);int     i2c_write(struct i2c_bus *bus, unsigned char addr,		  unsigned char b1, unsigned char b2, int both);int	i2c_init(void);#endif /* I2C_H */