1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011 Justin Hibbits
5 * Copyright (c) 2009 Nathan Whitehorn
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/cpu.h>
34 #include <sys/kernel.h>
35 #include <sys/limits.h>
36 #include <sys/module.h>
37
38 #include <dev/ofw/ofw_bus.h>
39 #include <dev/ofw/openfirm.h>
40
41 #include "cpufreq_if.h"
42 #include "powerpc/powermac/pmuvar.h"
43
44 struct pmufreq_softc {
45 device_t dev;
46 uint32_t minfreq;
47 uint32_t maxfreq;
48 uint32_t curfreq;
49 };
50
51 static void pmufreq_identify(driver_t *driver, device_t parent);
52 static int pmufreq_probe(device_t dev);
53 static int pmufreq_attach(device_t dev);
54 static int pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
55 static int pmufreq_set(device_t dev, const struct cf_setting *set);
56 static int pmufreq_get(device_t dev, struct cf_setting *set);
57 static int pmufreq_type(device_t dev, int *type);
58
59 static device_method_t pmufreq_methods[] = {
60 /* Device interface */
61 DEVMETHOD(device_identify, pmufreq_identify),
62 DEVMETHOD(device_probe, pmufreq_probe),
63 DEVMETHOD(device_attach, pmufreq_attach),
64
65 /* cpufreq interface */
66 DEVMETHOD(cpufreq_drv_set, pmufreq_set),
67 DEVMETHOD(cpufreq_drv_get, pmufreq_get),
68 DEVMETHOD(cpufreq_drv_type, pmufreq_type),
69 DEVMETHOD(cpufreq_drv_settings, pmufreq_settings),
70 {0, 0}
71 };
72
73 static driver_t pmufreq_driver = {
74 "pmufreq",
75 pmufreq_methods,
76 sizeof(struct pmufreq_softc)
77 };
78
79 DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, 0, 0);
80
81 static void
pmufreq_identify(driver_t * driver,device_t parent)82 pmufreq_identify(driver_t *driver, device_t parent)
83 {
84 phandle_t node;
85 uint32_t min_freq;
86
87 node = ofw_bus_get_node(parent);
88 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
89 return;
90
91 /* Make sure we're not being doubly invoked. */
92 if (device_find_child(parent, "pmufreq", -1) != NULL)
93 return;
94
95 /*
96 * We attach a child for every CPU since settings need to
97 * be performed on every CPU in the SMP case.
98 */
99 if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
100 device_printf(parent, "add pmufreq child failed\n");
101 }
102
103 static int
pmufreq_probe(device_t dev)104 pmufreq_probe(device_t dev)
105 {
106 phandle_t node;
107 uint32_t min_freq;
108
109 if (resource_disabled("pmufreq", 0))
110 return (ENXIO);
111
112 node = ofw_bus_get_node(device_get_parent(dev));
113 /*
114 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
115 * properties of the 'cpu' node.
116 */
117 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
118 return (ENXIO);
119 device_set_desc(dev, "PMU-based frequency scaling");
120 return (0);
121 }
122
123 static int
pmufreq_attach(device_t dev)124 pmufreq_attach(device_t dev)
125 {
126 struct pmufreq_softc *sc;
127 phandle_t node;
128
129 sc = device_get_softc(dev);
130 sc->dev = dev;
131
132 node = ofw_bus_get_node(device_get_parent(dev));
133 OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
134 OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
135 OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
136 sc->minfreq /= 1000000;
137 sc->maxfreq /= 1000000;
138 sc->curfreq /= 1000000;
139
140 cpufreq_register(dev);
141 return (0);
142 }
143
144 static int
pmufreq_settings(device_t dev,struct cf_setting * sets,int * count)145 pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
146 {
147 struct pmufreq_softc *sc;
148
149 sc = device_get_softc(dev);
150 if (sets == NULL || count == NULL)
151 return (EINVAL);
152 if (*count < 2)
153 return (E2BIG);
154
155 /* Return a list of valid settings for this driver. */
156 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
157
158 sets[0].freq = sc->maxfreq; sets[0].dev = dev;
159 sets[1].freq = sc->minfreq; sets[1].dev = dev;
160 /* Set high latency for CPU frequency changes, it's a tedious process. */
161 sets[0].lat = INT_MAX;
162 sets[1].lat = INT_MAX;
163 *count = 2;
164
165 return (0);
166 }
167
168 static int
pmufreq_set(device_t dev,const struct cf_setting * set)169 pmufreq_set(device_t dev, const struct cf_setting *set)
170 {
171 struct pmufreq_softc *sc;
172 int error, speed_sel;
173
174 if (set == NULL)
175 return (EINVAL);
176
177 sc = device_get_softc(dev);
178
179 if (set->freq == sc->maxfreq)
180 speed_sel = 0;
181 else
182 speed_sel = 1;
183
184 error = pmu_set_speed(speed_sel);
185 if (error == 0)
186 sc->curfreq = set->freq;
187
188 return (error);
189 }
190
191 static int
pmufreq_get(device_t dev,struct cf_setting * set)192 pmufreq_get(device_t dev, struct cf_setting *set)
193 {
194 struct pmufreq_softc *sc;
195
196 if (set == NULL)
197 return (EINVAL);
198 sc = device_get_softc(dev);
199
200 set->freq = sc->curfreq;
201 set->dev = dev;
202
203 return (0);
204 }
205
206 static int
pmufreq_type(device_t dev,int * type)207 pmufreq_type(device_t dev, int *type)
208 {
209
210 if (type == NULL)
211 return (EINVAL);
212
213 *type = CPUFREQ_TYPE_ABSOLUTE;
214 return (0);
215 }
216