freebsd-dev/sys/powerpc/cpufreq/pmufreq.c

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2011 Justin Hibbits
* Copyright (c) 2009 Nathan Whitehorn
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/openfirm.h>
#include "cpufreq_if.h"
#include "powerpc/powermac/pmuvar.h"
struct pmufreq_softc {
device_t dev;
uint32_t minfreq;
uint32_t maxfreq;
uint32_t curfreq;
};
static void pmufreq_identify(driver_t *driver, device_t parent);
static int pmufreq_probe(device_t dev);
static int pmufreq_attach(device_t dev);
static int pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
static int pmufreq_set(device_t dev, const struct cf_setting *set);
static int pmufreq_get(device_t dev, struct cf_setting *set);
static int pmufreq_type(device_t dev, int *type);
static device_method_t pmufreq_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, pmufreq_identify),
DEVMETHOD(device_probe, pmufreq_probe),
DEVMETHOD(device_attach, pmufreq_attach),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, pmufreq_set),
DEVMETHOD(cpufreq_drv_get, pmufreq_get),
DEVMETHOD(cpufreq_drv_type, pmufreq_type),
DEVMETHOD(cpufreq_drv_settings, pmufreq_settings),
{0, 0}
};
static driver_t pmufreq_driver = {
"pmufreq",
pmufreq_methods,
sizeof(struct pmufreq_softc)
};
static devclass_t pmufreq_devclass;
DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, pmufreq_devclass, 0, 0);
static void
pmufreq_identify(driver_t *driver, device_t parent)
{
phandle_t node;
uint32_t min_freq;
node = ofw_bus_get_node(parent);
if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
return;
/* Make sure we're not being doubly invoked. */
if (device_find_child(parent, "pmufreq", -1) != NULL)
return;
/*
* We attach a child for every CPU since settings need to
* be performed on every CPU in the SMP case.
*/
if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
device_printf(parent, "add pmufreq child failed\n");
}
static int
pmufreq_probe(device_t dev)
{
struct pmufreq_softc *sc;
phandle_t node;
uint32_t min_freq;
if (resource_disabled("pmufreq", 0))
return (ENXIO);
sc = device_get_softc(dev);
node = ofw_bus_get_node(device_get_parent(dev));
/*
* A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
* properties of the 'cpu' node.
*/
if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
return (ENXIO);
device_set_desc(dev, "PMU-based frequency scaling");
return (0);
}
static int
pmufreq_attach(device_t dev)
{
struct pmufreq_softc *sc;
phandle_t node;
sc = device_get_softc(dev);
sc->dev = dev;
node = ofw_bus_get_node(device_get_parent(dev));
OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
sc->minfreq /= 1000000;
sc->maxfreq /= 1000000;
sc->curfreq /= 1000000;
cpufreq_register(dev);
return (0);
}
static int
pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
{
struct pmufreq_softc *sc;
sc = device_get_softc(dev);
if (sets == NULL || count == NULL)
return (EINVAL);
if (*count < 2)
return (E2BIG);
/* Return a list of valid settings for this driver. */
memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
sets[0].freq = sc->maxfreq; sets[0].dev = dev;
sets[1].freq = sc->minfreq; sets[1].dev = dev;
/* Set high latency for CPU frequency changes, it's a tedious process. */
sets[0].lat = INT_MAX;
sets[1].lat = INT_MAX;
*count = 2;
return (0);
}
static int
pmufreq_set(device_t dev, const struct cf_setting *set)
{
struct pmufreq_softc *sc;
int error, speed_sel;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
if (set->freq == sc->maxfreq)
speed_sel = 0;
else
speed_sel = 1;
error = pmu_set_speed(speed_sel);
if (error == 0)
sc->curfreq = set->freq;
return (error);
}
static int
pmufreq_get(device_t dev, struct cf_setting *set)
{
struct pmufreq_softc *sc;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
set->freq = sc->curfreq;
set->dev = dev;
return (0);
}
static int
pmufreq_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_ABSOLUTE;
return (0);
}