9eb9db93da
switching capabilities of the MPC7447A and MPC7448.
113 lines
3.2 KiB
C
113 lines
3.2 KiB
C
/*-
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* Copyright (c) 2009 Nathan Whitehorn
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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 ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* 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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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/module.h>
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#include <sys/bus.h>
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#include <sys/conf.h>
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#include <sys/cpu.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <dev/ofw/ofw_bus.h>
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#include <dev/ofw/openfirm.h>
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#include <powerpc/powermac/macgpiovar.h>
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static int vcoregpio_probe(device_t);
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static int vcoregpio_attach(device_t);
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static void vcoregpio_pre_change(device_t, const struct cf_level *level);
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static void vcoregpio_post_change(device_t, const struct cf_level *level);
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static device_method_t vcoregpio_methods[] = {
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/* Device interface */
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DEVMETHOD(device_probe, vcoregpio_probe),
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DEVMETHOD(device_attach, vcoregpio_attach),
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{ 0, 0 },
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};
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static driver_t vcoregpio_driver = {
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"vcoregpio",
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vcoregpio_methods,
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0
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};
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static devclass_t vcoregpio_devclass;
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DRIVER_MODULE(vcoregpio, macgpio, vcoregpio_driver, vcoregpio_devclass, 0, 0);
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static int
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vcoregpio_probe(device_t dev)
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{
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const char *name = ofw_bus_get_name(dev);
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if (strcmp(name, "cpu-vcore-select") != 0)
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return (ENXIO);
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device_set_desc(dev, "CPU Core Voltage Control");
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return (0);
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}
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static int
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vcoregpio_attach(device_t dev)
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{
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EVENTHANDLER_REGISTER(cpufreq_pre_change, vcoregpio_pre_change, dev,
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EVENTHANDLER_PRI_ANY);
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EVENTHANDLER_REGISTER(cpufreq_post_change, vcoregpio_post_change, dev,
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EVENTHANDLER_PRI_ANY);
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return (0);
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}
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static void
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vcoregpio_pre_change(device_t dev, const struct cf_level *level)
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{
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if (level->rel_set[0].freq == 10000 /* max */) {
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/*
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* Make sure the CPU voltage is raised before we raise
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* the clock.
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*/
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macgpio_write(dev, GPIO_DDR_OUTPUT | 1);
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DELAY(1000);
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}
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}
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static void
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vcoregpio_post_change(device_t dev, const struct cf_level *level)
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{
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if (level->rel_set[0].freq < 10000 /* max */) {
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DELAY(1000);
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/* We are safe to reduce CPU voltage now */
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macgpio_write(dev, GPIO_DDR_OUTPUT | 0);
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}
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}
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