freebsd-dev/sys/dev/iicbus/iic.h

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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.
*
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* $FreeBSD$
*
*/
#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 */
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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 IIC_RDRW_MAX_MSGS 42
#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 */
Fix numerous issues in iic(4) and iicbus(4): --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)
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#define I2CSADDR _IOW('i', 8, uint8_t) /* set slave address for future I/O */
#endif