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/*-
* 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/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/openfirm.h>
#include <powerpc/powermac/macgpiovar.h>
static int vcoregpio_probe(device_t);
static int vcoregpio_attach(device_t);
static void vcoregpio_pre_change(device_t, const struct cf_level *level);
static void vcoregpio_post_change(device_t, const struct cf_level *level);
static device_method_t vcoregpio_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, vcoregpio_probe),
DEVMETHOD(device_attach, vcoregpio_attach),
{ 0, 0 },
};
static driver_t vcoregpio_driver = {
"vcoregpio",
vcoregpio_methods,
0
};
static devclass_t vcoregpio_devclass;
DRIVER_MODULE(vcoregpio, macgpio, vcoregpio_driver, vcoregpio_devclass, 0, 0);
static int
vcoregpio_probe(device_t dev)
{
const char *name = ofw_bus_get_name(dev);
if (strcmp(name, "cpu-vcore-select") != 0)
return (ENXIO);
device_set_desc(dev, "CPU Core Voltage Control");
return (0);
}
static int
vcoregpio_attach(device_t dev)
{
EVENTHANDLER_REGISTER(cpufreq_pre_change, vcoregpio_pre_change, dev,
EVENTHANDLER_PRI_ANY);
EVENTHANDLER_REGISTER(cpufreq_post_change, vcoregpio_post_change, dev,
EVENTHANDLER_PRI_ANY);
return (0);
}
static void
vcoregpio_pre_change(device_t dev, const struct cf_level *level)
{
if (level->rel_set[0].freq == 10000 /* max */) {
/*
* Make sure the CPU voltage is raised before we raise
* the clock.
*/
macgpio_write(dev, GPIO_DDR_OUTPUT | 1);
DELAY(1000);
}
}
static void
vcoregpio_post_change(device_t dev, const struct cf_level *level)
{
if (level->rel_set[0].freq < 10000 /* max */) {
DELAY(1000);
/* We are safe to reduce CPU voltage now */
macgpio_write(dev, GPIO_DDR_OUTPUT | 0);
}
}
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