25e5e803e7
--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
/*-
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* Copyright (c) 1998 Nicolas Souchu
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*
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*/
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#ifndef __IIC_H
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#define __IIC_H
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#include <sys/ioccom.h>
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/* Designed to be compatible with linux's struct i2c_msg */
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struct iic_msg
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{
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uint16_t slave;
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uint16_t flags;
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#define IIC_M_WR 0 /* Fake flag for write */
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#define IIC_M_RD 0x0001 /* read vs write */
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#define IIC_M_NOSTOP 0x0002 /* do not send a I2C stop after message */
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#define IIC_M_NOSTART 0x0004 /* do not send a I2C start before message */
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uint16_t len; /* msg length */
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uint8_t * buf;
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};
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struct iiccmd {
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u_char slave;
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int count;
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int last;
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char *buf;
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};
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struct iic_rdwr_data {
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struct iic_msg *msgs;
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uint32_t nmsgs;
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};
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#define I2CSTART _IOW('i', 1, struct iiccmd) /* start condition */
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#define I2CSTOP _IO('i', 2) /* stop condition */
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#define I2CRSTCARD _IOW('i', 3, struct iiccmd) /* reset the card */
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#define I2CWRITE _IOW('i', 4, struct iiccmd) /* send data */
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#define I2CREAD _IOW('i', 5, struct iiccmd) /* receive data */
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#define I2CRDWR _IOW('i', 6, struct iic_rdwr_data) /* General read/write interface */
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#define I2CRPTSTART _IOW('i', 7, struct iiccmd) /* repeated start */
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#define I2CSADDR _IOW('i', 8, uint8_t) /* set slave address for future I/O */
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#endif
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