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)
142 lines
2.9 KiB
Objective-C
142 lines
2.9 KiB
Objective-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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#include <sys/bus.h>
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#include <dev/iicbus/iic.h>
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INTERFACE iicbus;
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CODE {
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static u_int
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iicbus_default_frequency(device_t bus, u_char speed)
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{
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return (100000);
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}
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};
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#
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# Interpret interrupt
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#
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METHOD int intr {
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device_t dev;
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int event;
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char *buf;
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};
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#
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# iicbus callback
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# Request ownership of bus
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# index: IIC_REQUEST_BUS or IIC_RELEASE_BUS
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# data: pointer to int containing IIC_WAIT or IIC_DONTWAIT and either IIC_INTR or IIC_NOINTR
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# This function is allowed to sleep if *data contains IIC_WAIT.
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#
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METHOD int callback {
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device_t dev;
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int index;
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caddr_t data;
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};
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#
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# Send REPEATED_START condition
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#
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METHOD int repeated_start {
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device_t dev;
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u_char slave;
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int timeout;
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};
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#
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# Send START condition
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#
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METHOD int start {
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device_t dev;
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u_char slave;
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int timeout;
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};
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#
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# Send STOP condition
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#
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METHOD int stop {
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device_t dev;
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};
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#
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# Read from I2C bus
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#
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METHOD int read {
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device_t dev;
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char *buf;
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int len;
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int *bytes;
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int last;
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int delay;
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};
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#
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# Write to the I2C bus
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#
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METHOD int write {
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device_t dev;
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const char *buf;
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int len;
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int *bytes;
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int timeout;
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};
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#
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# Reset I2C bus
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#
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METHOD int reset {
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device_t dev;
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u_char speed;
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u_char addr;
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u_char *oldaddr;
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};
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#
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# Generalized Read/Write interface
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#
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METHOD int transfer {
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device_t dev;
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struct iic_msg *msgs;
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uint32_t nmsgs;
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};
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#
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# Return the frequency in Hz for the bus running at the given
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# symbolic speed. Only the IIC_SLOW speed has meaning, it is always
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# 100KHz. The UNKNOWN, FAST, and FASTEST rates all map to the
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# configured bus frequency, or 100KHz when not otherwise configured.
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#
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METHOD u_int get_frequency {
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device_t dev;
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u_char speed;
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} DEFAULT iicbus_default_frequency;
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