2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2009 Nathan Whitehorn
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #include <sys/sysctl.h>
42 #include <dev/ofw/ofw_bus.h>
43 #include <dev/ofw/openfirm.h>
45 #include <powerpc/powermac/macgpiovar.h>
47 static int vcoregpio_probe(device_t);
48 static int vcoregpio_attach(device_t);
49 static void vcoregpio_pre_change(device_t, const struct cf_level *level);
50 static void vcoregpio_post_change(device_t, const struct cf_level *level);
52 static device_method_t vcoregpio_methods[] = {
53 /* Device interface */
54 DEVMETHOD(device_probe, vcoregpio_probe),
55 DEVMETHOD(device_attach, vcoregpio_attach),
59 static driver_t vcoregpio_driver = {
65 static devclass_t vcoregpio_devclass;
67 DRIVER_MODULE(vcoregpio, macgpio, vcoregpio_driver, vcoregpio_devclass, 0, 0);
70 vcoregpio_probe(device_t dev)
72 const char *name = ofw_bus_get_name(dev);
74 if (strcmp(name, "cpu-vcore-select") != 0)
77 device_set_desc(dev, "CPU Core Voltage Control");
82 vcoregpio_attach(device_t dev)
84 EVENTHANDLER_REGISTER(cpufreq_pre_change, vcoregpio_pre_change, dev,
85 EVENTHANDLER_PRI_ANY);
86 EVENTHANDLER_REGISTER(cpufreq_post_change, vcoregpio_post_change, dev,
87 EVENTHANDLER_PRI_ANY);
93 vcoregpio_pre_change(device_t dev, const struct cf_level *level)
95 if (level->rel_set[0].freq == 10000 /* max */) {
97 * Make sure the CPU voltage is raised before we raise
100 macgpio_write(dev, GPIO_DDR_OUTPUT | 1);
106 vcoregpio_post_change(device_t dev, const struct cf_level *level)
108 if (level->rel_set[0].freq < 10000 /* max */) {
110 /* We are safe to reduce CPU voltage now */
111 macgpio_write(dev, GPIO_DDR_OUTPUT | 0);