freebsd-nq/sys/dev/iicbus/iicbus.h
Ian Lepore 873bf31b2b Restore the ability for i2c slave devices to do IO from their probe method.
r348164 added code to iicbus_request_bus/iicbus_release_bus to automatically
call device_busy()/device_unbusy() as part of aquiring exclusive use of the
bus (so modules can't be unloaded while the bus is exclusively owned and/or
IO is in progress).  That broke the ability to do i2c IO from a slave device
probe method, because the slave isn't attached yet, so calling device_busy()
triggers a sanity-check panic for trying to busy a non-attached device.

Now we check whether the device status is < DS_ATTACHING, and if so we busy
the iicbus rather than the slave device.  I think this leaves a small window
where a module could be unloaded while probing is in progress.  But I think
that's true of all devices, and probably should be fixed by introducing a
DS_PROBING state for devices, and handling that at various points in the
newbus code.
2019-07-08 20:26:56 +00:00

88 lines
2.9 KiB
C

/*-
* 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.
*
* $FreeBSD$
*
*/
#ifndef __IICBUS_H
#define __IICBUS_H
#include <sys/_lock.h>
#include <sys/_mutex.h>
#define IICBUS_IVAR(d) (struct iicbus_ivar *) device_get_ivars(d)
#define IICBUS_SOFTC(d) (struct iicbus_softc *) device_get_softc(d)
struct iicbus_softc
{
device_t dev; /* Myself */
device_t owner; /* iicbus owner device structure */
device_t busydev; /* iicbus_release_bus calls unbusy on this */
u_int owncount; /* iicbus ownership nesting count */
u_char started; /* address of the 'started' slave
* 0 if no start condition succeeded */
u_char strict; /* deny operations that violate the
* I2C protocol */
struct mtx lock;
u_int bus_freq; /* Configured bus Hz. */
};
struct iicbus_ivar
{
uint32_t addr;
struct resource_list rl;
};
enum {
IICBUS_IVAR_ADDR /* Address or base address */
};
#define IICBUS_ACCESSOR(A, B, T) \
__BUS_ACCESSOR(iicbus, A, IICBUS, B, T)
IICBUS_ACCESSOR(addr, ADDR, uint32_t)
#define IICBUS_LOCK(sc) mtx_lock(&(sc)->lock)
#define IICBUS_UNLOCK(sc) mtx_unlock(&(sc)->lock)
#define IICBUS_ASSERT_LOCKED(sc) mtx_assert(&(sc)->lock, MA_OWNED)
#ifdef FDT
#define IICBUS_FDT_PNP_INFO(t) FDTCOMPAT_PNP_INFO(t, iicbus)
#else
#define IICBUS_FDT_PNP_INFO(t)
#endif
int iicbus_generic_intr(device_t dev, int event, char *buf);
void iicbus_init_frequency(device_t dev, u_int bus_freq);
extern driver_t iicbus_driver;
extern devclass_t iicbus_devclass;
extern driver_t ofw_iicbus_driver;
extern devclass_t ofw_iicbus_devclass;
#endif