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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
37 #include "cpufreq_if.h"
44 static void dfs_identify(driver_t *driver, device_t parent);
45 static int dfs_probe(device_t dev);
46 static int dfs_attach(device_t dev);
47 static int dfs_settings(device_t dev, struct cf_setting *sets, int *count);
48 static int dfs_set(device_t dev, const struct cf_setting *set);
49 static int dfs_get(device_t dev, struct cf_setting *set);
50 static int dfs_type(device_t dev, int *type);
52 static device_method_t dfs_methods[] = {
53 /* Device interface */
54 DEVMETHOD(device_identify, dfs_identify),
55 DEVMETHOD(device_probe, dfs_probe),
56 DEVMETHOD(device_attach, dfs_attach),
58 /* cpufreq interface */
59 DEVMETHOD(cpufreq_drv_set, dfs_set),
60 DEVMETHOD(cpufreq_drv_get, dfs_get),
61 DEVMETHOD(cpufreq_drv_type, dfs_type),
62 DEVMETHOD(cpufreq_drv_settings, dfs_settings),
67 static driver_t dfs_driver = {
70 sizeof(struct dfs_softc)
73 static devclass_t dfs_devclass;
74 DRIVER_MODULE(dfs, cpu, dfs_driver, dfs_devclass, 0, 0);
77 * Bits of the HID1 register to enable DFS. See page 2-24 of "MPC7450
78 * RISC Microprocessor Family Reference Manual", rev. 5.
81 #define HID1_DFS2 (1UL << 22)
82 #define HID1_DFS4 (1UL << 23)
85 dfs_identify(driver_t *driver, device_t parent)
90 /* Check for an MPC 7447A or 7448 CPU */
99 /* Make sure we're not being doubly invoked. */
100 if (device_find_child(parent, "dfs", -1) != NULL)
104 * We attach a child for every CPU since settings need to
105 * be performed on every CPU in the SMP case.
107 if (BUS_ADD_CHILD(parent, 10, "dfs", -1) == NULL)
108 device_printf(parent, "add dfs child failed\n");
112 dfs_probe(device_t dev)
114 if (resource_disabled("dfs", 0))
117 device_set_desc(dev, "Dynamic Frequency Switching");
122 dfs_attach(device_t dev)
124 struct dfs_softc *sc;
127 sc = device_get_softc(dev);
130 vers = mfpvr() >> 16;
132 /* The 7448 supports divide-by-four as well */
136 cpufreq_register(dev);
141 dfs_settings(device_t dev, struct cf_setting *sets, int *count)
143 struct dfs_softc *sc;
146 sc = device_get_softc(dev);
147 states = sc->dfs4 ? 3 : 2;
148 if (sets == NULL || count == NULL)
153 /* Return a list of valid settings for this driver. */
154 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * states);
156 sets[0].freq = 10000; sets[0].dev = dev;
157 sets[1].freq = 5000; sets[1].dev = dev;
159 sets[2].freq = 2500; sets[2].dev = dev;
166 dfs_set(device_t dev, const struct cf_setting *set)
173 hid1 = mfspr(SPR_HID1);
174 hid1 &= ~(HID1_DFS2 | HID1_DFS4);
176 if (set->freq == 5000)
178 else if (set->freq == 2500)
182 * Now set the HID1 register with new values. Calling sequence
183 * taken from page 2-26 of the MPC7450 family CPU manual.
187 mtspr(SPR_HID1, hid1);
188 powerpc_sync(); isync();
194 dfs_get(device_t dev, struct cf_setting *set)
196 struct dfs_softc *sc;
201 sc = device_get_softc(dev);
203 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
205 hid1 = mfspr(SPR_HID1);
208 if (hid1 & HID1_DFS2)
210 else if (sc->dfs4 && (hid1 & HID1_DFS4))
219 dfs_type(device_t dev, int *type)
225 *type = CPUFREQ_TYPE_RELATIVE;