minix/sys/dev/i2c/i2c_io.h
Thomas Cort 437177b028 i2c: increase BUFLEN/CMDLEN to 128, add page flag.
128 byte reads are much more common than 32 byte reads. The message
passing + setup/teardown for a read is much more expensive, in terms
of time, than the reading itself. A slightly bigger struct is well
worth the time savings. This reduces read times for /dev/eeprom
from 57 seconds per 4KB to 14 seconds.

Additionally, make sending the page address in the eeprom driver
and utility optional. This can save a little time when reading
within the same page and allows support for smaller devices that
don't support pages (example: chips containing EDID).

Change-Id: Ie48087caee40c11fa241d1555fce9309ddd27b43
2013-07-27 08:21:37 -04:00

106 lines
3.9 KiB
C

/* $NetBSD: i2c_io.h,v 1.3 2012/04/22 14:10:36 pgoyette Exp $ */
/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Jason R. Thorpe for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _DEV_I2C_I2C_IO_H_
#define _DEV_I2C_I2C_IO_H_
#include <sys/ioccom.h>
/* I2C bus address. */
typedef uint16_t i2c_addr_t;
/* High-level I2C operations. */
#define I2C_OPMASK_STOP 1
#define I2C_OPMASK_WRITE 2
#define I2C_OPMASK_BLKMODE 4
#define I2C_OP_STOP_P(x) (((int)(x) & I2C_OPMASK_STOP) != 0)
#define I2C_OP_WRITE_P(x) (((int)(x) & I2C_OPMASK_WRITE) != 0)
#define I2C_OP_READ_P(x) (!I2C_OP_WRITE_P(x))
#define I2C_OP_BLKMODE_P(x) (((int)(x) & I2C_OPMASK_BLKMODE) != 0)
typedef enum {
I2C_OP_READ = 0,
I2C_OP_READ_WITH_STOP = I2C_OPMASK_STOP,
I2C_OP_WRITE = I2C_OPMASK_WRITE,
I2C_OP_WRITE_WITH_STOP = I2C_OPMASK_WRITE | I2C_OPMASK_STOP,
I2C_OP_READ_BLOCK = I2C_OPMASK_BLKMODE | I2C_OPMASK_STOP,
I2C_OP_WRITE_BLOCK = I2C_OPMASK_BLKMODE | I2C_OPMASK_WRITE |
I2C_OPMASK_STOP,
} i2c_op_t;
/*
* This structure describes a single I2C control script fragment.
*
* Note that use of this scripted API allows for support of automated
* SMBus controllers. The following table maps SMBus operations to
* script fragment configuration:
*
* SMBus "write byte": I2C_OP_WRITE_WITH_STOP
* cmdlen = 1
*
* SMBus "read byte": I2C_OP_READ_WITH_STOP
* cmdlen = 1
*
* SMBus "receive byte": I2C_OP_READ_WITH_STOP
* cmdlen = 0
*
* Note that while each of these 3 SMBus operations implies a STOP
* (which an automated controller will likely perform automatically),
* non-SMBus clients may continue to function even if they issue
* I2C_OP_WRITE and I2C_OP_READ.
*/
/*
* I2C_IOCTL_EXEC:
*
* User ioctl to execute an i2c operation.
*/
typedef struct i2c_ioctl_exec {
i2c_op_t iie_op; /* operation to perform */
i2c_addr_t iie_addr; /* address of device */
const void *iie_cmd; /* pointer to command */
size_t iie_cmdlen; /* length of command */
void *iie_buf; /* pointer to data buffer */
size_t iie_buflen; /* length of data buffer */
} i2c_ioctl_exec_t;
#define I2C_EXEC_MAX_CMDLEN 128
#define I2C_EXEC_MAX_BUFLEN 128
#define I2C_IOCTL_EXEC _IOW('I', 0, i2c_ioctl_exec_t)
#endif /* _DEV_I2C_I2C_IO_H_ */