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