0afebee290
--Allow multiple open iic fds by storing addressing state in cdevpriv
--Fix, as much as possible, the baked-in race conditions in the iic
ioctl interface by requesting bus ownership on I2CSTART, releasing it on
I2CSTOP/I2CRSTCARD, and requiring bus ownership by the current cdevpriv
to use the I/O ioctls
--Reduce internal iic buffer size and remove 1K read/write limit by
iteratively calling iicbus_read/iicbus_write
--Eliminate dynamic allocation in I2CWRITE/I2CREAD
--Move handling of I2CRDWR to separate function and improve error handling
--Add new I2CSADDR ioctl to store address in current cdevpriv so that
I2CSTART is not needed for read(2)/write(2) to work
--Redesign iicbus_request_bus() and iicbus_release_bus():
--iicbus_request_bus() no longer falls through if the bus is already
owned by the requesting device. Multiple threads on the same device may
want exclusive access. Also, iicbus_release_bus() was never
device-recursive anyway.
--Previously, if IICBUS_CALLBACK failed in iicbus_release_bus(), but
the following iicbus_poll() call succeeded, IICBUS_CALLBACK would not be
issued again
--Do not hold iicbus mtx during IICBUS_CALLBACK call. There are
several drivers that may sleep in IICBUS_CALLBACK, if IIC_WAIT is passed.
--Do not loop in iicbus_request_bus if IICBUS_CALLBACK returns
EWOULDBLOCK; instead pass that to the caller so that it can retry if so
desired.
Differential Revision: https://reviews.freebsd.org/D2140
Reviewed by: imp, jhb, loos
Approved by: kib (mentor)
69 lines
2.5 KiB
C
69 lines
2.5 KiB
C
/*-
|
|
* Copyright (c) 1998 Nicolas Souchu
|
|
* All rights reserved.
|
|
*
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
|
|
*
|
|
* $FreeBSD$
|
|
*
|
|
*/
|
|
#ifndef __IIC_H
|
|
#define __IIC_H
|
|
|
|
#include <sys/ioccom.h>
|
|
|
|
/* Designed to be compatible with linux's struct i2c_msg */
|
|
struct iic_msg
|
|
{
|
|
uint16_t slave;
|
|
uint16_t flags;
|
|
#define IIC_M_WR 0 /* Fake flag for write */
|
|
#define IIC_M_RD 0x0001 /* read vs write */
|
|
#define IIC_M_NOSTOP 0x0002 /* do not send a I2C stop after message */
|
|
#define IIC_M_NOSTART 0x0004 /* do not send a I2C start before message */
|
|
uint16_t len; /* msg length */
|
|
uint8_t * buf;
|
|
};
|
|
|
|
struct iiccmd {
|
|
u_char slave;
|
|
int count;
|
|
int last;
|
|
char *buf;
|
|
};
|
|
|
|
struct iic_rdwr_data {
|
|
struct iic_msg *msgs;
|
|
uint32_t nmsgs;
|
|
};
|
|
|
|
#define I2CSTART _IOW('i', 1, struct iiccmd) /* start condition */
|
|
#define I2CSTOP _IO('i', 2) /* stop condition */
|
|
#define I2CRSTCARD _IOW('i', 3, struct iiccmd) /* reset the card */
|
|
#define I2CWRITE _IOW('i', 4, struct iiccmd) /* send data */
|
|
#define I2CREAD _IOW('i', 5, struct iiccmd) /* receive data */
|
|
#define I2CRDWR _IOW('i', 6, struct iic_rdwr_data) /* General read/write interface */
|
|
#define I2CRPTSTART _IOW('i', 7, struct iiccmd) /* repeated start */
|
|
#define I2CSADDR _IOW('i', 8, uint8_t) /* set slave address for future I/O */
|
|
|
|
#endif
|