dev/fdt/fdt_reset.c		optional fdt fdt_reset

dev/fdt/fdt_reset_if.m		optional fdt fdt_reset

/*-

 * Copyright (c) 2016 Stanislav Galabov

 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>

 * 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.

 *

 * $FreeBSD$

 */

#include <sys/cdefs.h>

#include <sys/param.h>

#include <sys/kernel.h>

#include <sys/lock.h>

#include <sys/mutex.h>

#include <sys/queue.h>

#include <sys/systm.h>

#include <dev/ofw/ofw_bus.h>

#include <dev/ofw/ofw_bus_subr.h>

#include "fdt_reset_if.h"

#include <dev/fdt/fdt_reset.h>

/*

 * Loop through all the tuples in the resets= property for a device, asserting

 * or deasserting each reset.

 *

 * Be liberal about errors for now: warn about a failure to (de)assert but keep

 * trying with any other resets in the list.  Return ENXIO if any errors were

 * found, and let the caller decide whether the problem is fatal.

 */

static int

assert_deassert_all(device_t consumer, boolean_t assert)

{

	phandle_t rnode;

	device_t resetdev;

	int resetnum, err, i, ncells;

	uint32_t *resets;

	boolean_t anyerrors;

	rnode = ofw_bus_get_node(consumer);

	ncells = OF_getencprop_alloc(rnode, "resets", sizeof(*resets),

	    (void **)&resets);

	if (!assert && ncells < 2) {

		device_printf(consumer, "Warning: No resets specified in fdt "

		    "data; device may not function.");

		return (ENXIO);

	}

	anyerrors = false;

	for (i = 0; i < ncells; i += 2) {

		resetdev = OF_device_from_xref(resets[i]);

		resetnum = resets[i + 1];

		if (resetdev == NULL) {

			if (!assert)

				device_printf(consumer, "Warning: can not find "

				    "driver for reset number %u; device may "

				    "not function\n", resetnum);

			anyerrors = true;

			continue;

		}

		if (assert)

			err = FDT_RESET_ASSERT(resetdev, resetnum);

		else

			err = FDT_RESET_DEASSERT(resetdev, resetnum);

		if (err != 0) {

			if (!assert)

				device_printf(consumer, "Warning: failed to "

				    "deassert reset number %u; device may not "

				    "function\n", resetnum);

			anyerrors = true;

		}

	}

	free(resets, M_OFWPROP);

	return (anyerrors ? ENXIO : 0);

}

int

fdt_reset_assert_all(device_t consumer)

{

	return (assert_deassert_all(consumer, true));

}

int

fdt_reset_deassert_all(device_t consumer)

{

	return (assert_deassert_all(consumer, false));

}

void

fdt_reset_register_provider(device_t provider)

{

	OF_device_register_xref(

	    OF_xref_from_node(ofw_bus_get_node(provider)), provider);

}

void

fdt_reset_unregister_provider(device_t provider)

{

	OF_device_register_xref(OF_xref_from_device(provider), NULL);

}

/*-

 * Copyright (c) 2016 Stanislav Galabov

 * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>

 * 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 ``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 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 DEV_FDT_RESET_H

#define DEV_FDT_RESET_H

#include "fdt_reset_if.h"

/*

 * Look up "resets" property in consumer's fdt data and assert or deassert all

 * configured resets.

 */

int fdt_reset_assert_all(device_t consumer);

int fdt_reset_deassert_all(device_t consumer);

/*

 * [Un]register the given device instance as a driver that implements the

 * fdt_clock interface.

 */

void fdt_reset_register_provider(device_t provider);

void fdt_reset_unregister_provider(device_t provider);

#endif /* DEV_FDT_RESET_H */

#-

# Copyright (c) 2016 Stanislav Galabov

# Copyright (c) 2014 Ian Lepore

# 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.

#

# $FreeBSD$

#

#include <sys/types.h>

#

# This is the interface that fdt_reset drivers provide to other drivers.

# In this context, reset refers to a reset signal provided to some other

# hardware component within the system.  They are most often found within

# embedded processors that have on-chip IO controllers.

#

INTERFACE fdt_reset;

#

# Enable/assert/apply the specified reset.

# Returns 0 on success or a standard errno value.

#

METHOD int assert {

	device_t	provider;

	int		index;

};

#

# Disable/de-assert/remove the specified reset.

# Returns 0 on success or a standard errno value.

#

METHOD int deassert {

	device_t	provider;

	int		index;

};