i2c.h

I2C总线LINUX驱动程序

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;
};

/* Internal numbers to terminate lists */
#define I2C_CLIENT_END 0xfffe

/* The numbers to use to set I2C bus address */
#define ANY_I2C_BUS 0xffff

/* The length of the option lists */
#define I2C_CLIENT_MAX_OPTS 48


/* ----- functions exported by i2c.o */

/* administration...
 */
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);

extern int i2c_add_driver(struct i2c_driver *);
extern int i2c_del_driver(struct i2c_driver *);

extern int i2c_attach_client(struct i2c_client *);
extern int i2c_detach_client(struct i2c_client *);

/* New function: This is to get an i2c_client-struct for controlling the 
   client either by using i2c_control-function or having the 
   client-module export functions that can be used with the i2c_client
   -struct. */
extern struct i2c_client *i2c_get_client(int driver_id, int adapter_id, 
					struct i2c_client *prev);

/* Should be used with new function
   extern struct i2c_client *i2c_get_client(int,int,struct i2c_client *);
   to make sure that client-struct is valid and that it is okay to access
   the i2c-client. 
   returns -EACCES if client doesn't allow use (default)
   returns -EBUSY if client doesn't allow multiple use (default) and 
   usage_count >0 */
extern int i2c_use_client(struct i2c_client *);
extern int i2c_release_client(struct i2c_client *);

/* returns -EBUSY if address has been taken, 0 if not. Note that the only
   other place at which this is called is within i2c_attach_client; so
   you can cheat by simply not registering. Not recommended, of course! */
extern int i2c_check_addr (struct i2c_adapter *adapter, int addr);

/* Detect function. It iterates over all possible addresses itself.
 * It will only call found_proc if some client is connected at the
 * specific address (unless a 'force' matched);
 */
typedef int i2c_client_found_addr_proc (struct i2c_adapter *adapter,
                                     int addr, unsigned short flags,int kind);

extern int i2c_probe(struct i2c_adapter *adapter, 
		struct i2c_client_address_data *address_data,
		i2c_client_found_addr_proc *found_proc);

static inline int i2c_client_command(struct i2c_client *client,
				     unsigned int cmd, void *arg)
{
	if (client->driver && client->driver->command)
		return client->driver->command(client, cmd, arg);
	else
		return -EINVAL;
}

/* An ioctl like call to set div. parameters of the adapter.
 */
extern int i2c_control(struct i2c_client *,unsigned int, unsigned long);

/* This call returns a unique low identifier for each registered adapter,
 * or -1 if the adapter was not registered. 
 */
extern int i2c_adapter_id(struct i2c_adapter *adap);



/* Return the functionality mask */
extern u32 i2c_get_functionality (struct i2c_adapter *adap);

/* Return 1 if adapter supports everything we need, 0 if not. */
extern int i2c_check_functionality (struct i2c_adapter *adap, u32 func);

/*
 * I2C Message - used for pure i2c transaction, also from /dev interface
 */
struct i2c_msg {
	__u16 addr;	/* slave address			*/
	__u16 flags;		
#define I2C_M_TEN	0x10	/* we have a ten bit chip address	*/
#define I2C_M_RD	0x01
#define I2C_M_NOSTART	0x4000
#define I2C_M_REV_DIR_ADDR	0x2000
#define I2C_M_IGNORE_NAK	0x1000
#define I2C_M_NO_RD_ACK		0x0800
#define I2C_M_RECV_LEN		0x0400 /* length will be first received byte */
#define I2C_M_RECV_PEC		0x0200 /* receive one more than the returned
					  length byte for the PEC */
	__u16 len;		/* msg length				*/
	__u8 *buf;		/* pointer to msg data			*/
};

/* To determine what functionality is present */

#define I2C_FUNC_I2C			0x00000001
#define I2C_FUNC_10BIT_ADDR		0x00000002
#define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_{REV_DIR_ADDR,NOSTART,..} */
#define I2C_FUNC_SMBUS_HWPEC_CALC	0x00000008 /* SMBus 2.0 */
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
#define I2C_FUNC_SMBUS_QUICK		0x00010000 
#define I2C_FUNC_SMBUS_READ_BYTE	0x00020000 
#define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000 
#define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000 
#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000 
#define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000 
#define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000 
#define I2C_FUNC_SMBUS_PROC_CALL	0x00800000 
#define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000 
#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 
#define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
#define I2C_FUNC_SMBUS_READ_I2C_BLOCK_2	 0x10000000 /* I2C-like block xfer  */
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK_2 0x20000000 /* w/ 2-byte reg. addr. */

#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
                             I2C_FUNC_SMBUS_WRITE_BYTE)
#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
                                  I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
                                  I2C_FUNC_SMBUS_WRITE_WORD_DATA)
#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
                                   I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
                                  I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
#define I2C_FUNC_SMBUS_I2C_BLOCK_2 (I2C_FUNC_SMBUS_READ_I2C_BLOCK_2 | \
                                    I2C_FUNC_SMBUS_WRITE_I2C_BLOCK_2)

#define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
                             I2C_FUNC_SMBUS_BYTE | \
                             I2C_FUNC_SMBUS_BYTE_DATA | \
                             I2C_FUNC_SMBUS_WORD_DATA | \
                             I2C_FUNC_SMBUS_PROC_CALL | \
                             I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
                             I2C_FUNC_SMBUS_I2C_BLOCK)

/* 
 * Data for SMBus Messages 
 */
#define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */	
#define I2C_SMBUS_I2C_BLOCK_MAX	32	/* Not specified but we use same structure */
union i2c_smbus_data {
	__u8 byte;
	__u16 word;
	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
	                       /* and one more for user-space compatibility */
};

/* smbus_access read or write markers */
#define I2C_SMBUS_READ	1
#define I2C_SMBUS_WRITE	0

/* SMBus transaction types (size parameter in the above functions) 
   Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
#define I2C_SMBUS_QUICK		    0
#define I2C_SMBUS_BYTE		    1
#define I2C_SMBUS_BYTE_DATA	    2 
#define I2C_SMBUS_WORD_DATA	    3
#define I2C_SMBUS_PROC_CALL	    4
#define I2C_SMBUS_BLOCK_DATA	    5
#define I2C_SMBUS_I2C_BLOCK_DATA    6
#define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */


/* ----- commands for the ioctl like i2c_command call:
 * note that additional calls are defined in the algorithm and hw 
 *	dependent layers - these can be listed here, or see the 
 *	corresponding header files.
 */
				/* -> bit-adapter specific ioctls	*/
#define I2C_RETRIES	0x0701	/* number of times a device address      */
				/* should be polled when not            */
                                /* acknowledging 			*/
#define I2C_TIMEOUT	0x0702	/* set timeout - call with int 		*/


/* this is for i2c-dev.c	*/
#define I2C_SLAVE	0x0703	/* Change slave address			*/
				/* Attn.: Slave address is 7 or 10 bits */
#define I2C_SLAVE_FORCE	0x0706	/* Change slave address			*/
				/* Attn.: Slave address is 7 or 10 bits */
				/* This changes the address, even if it */
				/* is already taken!			*/
#define I2C_TENBIT	0x0704	/* 0 for 7 bit addrs, != 0 for 10 bit	*/

#define I2C_FUNCS	0x0705	/* Get the adapter functionality */
#define I2C_RDWR	0x0707	/* Combined R/W transfer (one stop only)*/
#define I2C_PEC		0x0708	/* != 0 for SMBus PEC                   */

#define I2C_SMBUS	0x0720	/* SMBus-level access */

/* ----- I2C-DEV: char device interface stuff ------------------------- */

#define I2C_MAJOR	89		/* Device major number		*/

/* These defines are used for probing i2c client addresses */
/* Default fill of many variables */
#define I2C_CLIENT_DEFAULTS {I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END}

/* This is ugly. We need to evaluate I2C_CLIENT_MAX_OPTS before it is 
   stringified */
#define I2C_CLIENT_MODPARM_AUX1(x) "1-" #x "h"
#define I2C_CLIENT_MODPARM_AUX(x) I2C_CLIENT_MODPARM_AUX1(x)
#define I2C_CLIENT_MODPARM I2C_CLIENT_MODPARM_AUX(I2C_CLIENT_MAX_OPTS)

/* I2C_CLIENT_MODULE_PARM creates a module parameter, and puts it in the
   module header */

#define I2C_CLIENT_MODULE_PARM(var,desc) \
  static unsigned short var[I2C_CLIENT_MAX_OPTS] = I2C_CLIENT_DEFAULTS; \
  MODULE_PARM(var,I2C_CLIENT_MODPARM); \
  MODULE_PARM_DESC(var,desc)

/* This is the one you want to use in your own modules */
#define I2C_CLIENT_INSMOD \
  I2C_CLIENT_MODULE_PARM(probe, \
                      "List of adapter,address pairs to scan additionally"); \
  I2C_CLIENT_MODULE_PARM(probe_range, \
                      "List of adapter,start-addr,end-addr triples to scan " \
                      "additionally"); \
  I2C_CLIENT_MODULE_PARM(ignore, \
                      "List of adapter,address pairs not to scan"); \
  I2C_CLIENT_MODULE_PARM(ignore_range, \
                      "List of adapter,start-addr,end-addr triples not to " \
                      "scan"); \
  I2C_CLIENT_MODULE_PARM(force, \
                      "List of adapter,address pairs to boldly assume " \
                      "to be present"); \
  static struct i2c_client_address_data addr_data = \
                                       {normal_i2c, normal_i2c_range, \
                                        probe, probe_range, \
                                        ignore, ignore_range, \
                                        force}

/* Detect whether we are on the isa bus. If this returns true, all i2c
   access will fail! */
#define i2c_is_isa_client(clientptr) \
        ((clientptr)->adapter->algo->id == I2C_ALGO_ISA)
#define i2c_is_isa_adapter(adapptr) \
        ((adapptr)->algo->id == I2C_ALGO_ISA)

/* Tiny delay function used by the i2c bus drivers */
static inline void i2c_delay(signed long timeout)
{
	set_current_state(TASK_INTERRUPTIBLE);
	schedule_timeout(timeout);
}

#endif /* _LINUX_I2C_H */