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i2c_io.h revision 1.2 
      1 /*	$NetBSD: i2c_io.h,v 1.2 2005/12/11 12:21:22 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2003 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed for the NetBSD Project by
     20  *      Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 #ifndef _DEV_I2C_I2C_IO_H_
     39 #define	_DEV_I2C_I2C_IO_H_
     40 
     41 #include <sys/ioccom.h>
     42 
     43 /* I2C bus address. */
     44 typedef uint16_t i2c_addr_t;
     45 
     46 /* High-level I2C operations. */
     47 typedef enum {
     48 	I2C_OP_READ		= 0,
     49 	I2C_OP_READ_WITH_STOP	= 1,
     50 	I2C_OP_WRITE		= 2,
     51 	I2C_OP_WRITE_WITH_STOP	= 3,
     52 } i2c_op_t;
     53 
     54 #define	I2C_OP_READ_P(x)	(((int)(x) & 2) == 0)
     55 #define	I2C_OP_WRITE_P(x)	(! I2C_OP_READ_P(x))
     56 #define	I2C_OP_STOP_P(x)	(((int)(x) & 1) != 0)
     57 
     58 /*
     59  * This structure describes a single I2C control script fragment.
     60  *
     61  * Note that use of this scripted API allows for support of automated
     62  * SMBus controllers.  The following table maps SMBus operations to
     63  * script fragment configuration:
     64  *
     65  *	SMBus "write byte":		I2C_OP_WRITE_WITH_STOP
     66  *					cmdlen = 1
     67  *
     68  *	SMBus "read byte":		I2C_OP_READ_WITH_STOP
     69  *					cmdlen = 1
     70  *
     71  *	SMBus "receive byte":		I2C_OP_READ_WITH_STOP
     72  *					cmdlen = 0
     73  *
     74  * Note that while each of these 3 SMBus operations implies a STOP
     75  * (which an automated controller will likely perform automatically),
     76  * non-SMBus clients may continue to function even if they issue
     77  * I2C_OP_WRITE and I2C_OP_READ.
     78  */
     79 
     80 /*
     81  * I2C_IOCTL_EXEC:
     82  *
     83  *	User ioctl to execute an i2c operation.
     84  */
     85 typedef struct i2c_ioctl_exec {
     86 	i2c_op_t iie_op;		/* operation to perform */
     87 	i2c_addr_t iie_addr;		/* address of device */
     88 	const void *iie_cmd;		/* pointer to command */
     89 	size_t iie_cmdlen;		/* length of command */
     90 	void *iie_buf;			/* pointer to data buffer */
     91 	size_t iie_buflen;		/* length of data buffer */
     92 } i2c_ioctl_exec_t;
     93 #define	I2C_EXEC_MAX_CMDLEN	32
     94 #define	I2C_EXEC_MAX_BUFLEN	32
     95 
     96 #define	I2C_IOCTL_EXEC		 _IOW('I', 0, i2c_ioctl_exec_t)
     97 
     98 #endif /* _DEV_I2C_I2C_IO_H_ */
     99