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/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/cpu.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
37 #include <sys/module.h>
38
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/openfirm.h>
41
42 #include "cpufreq_if.h"
43 #include "powerpc/powermac/pmuvar.h"
44
45 struct pmufreq_softc {
46 device_t dev;
47 uint32_t minfreq;
48 uint32_t maxfreq;
49 uint32_t curfreq;
50 };
51
52 static void pmufreq_identify(driver_t *driver, device_t parent);
53 static int pmufreq_probe(device_t dev);
54 static int pmufreq_attach(device_t dev);
55 static int pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
56 static int pmufreq_set(device_t dev, const struct cf_setting *set);
57 static int pmufreq_get(device_t dev, struct cf_setting *set);
58 static int pmufreq_type(device_t dev, int *type);
59
60 static device_method_t pmufreq_methods[] = {
61 /* Device interface */
62 DEVMETHOD(device_identify, pmufreq_identify),
63 DEVMETHOD(device_probe, pmufreq_probe),
64 DEVMETHOD(device_attach, pmufreq_attach),
65
66 /* cpufreq interface */
67 DEVMETHOD(cpufreq_drv_set, pmufreq_set),
68 DEVMETHOD(cpufreq_drv_get, pmufreq_get),
69 DEVMETHOD(cpufreq_drv_type, pmufreq_type),
70 DEVMETHOD(cpufreq_drv_settings, pmufreq_settings),
71 {0, 0}
72 };
73
74 static driver_t pmufreq_driver = {
75 "pmufreq",
76 pmufreq_methods,
77 sizeof(struct pmufreq_softc)
78 };
79
80 DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, 0, 0);
81
82 static void
pmufreq_identify(driver_t * driver,device_t parent)83 pmufreq_identify(driver_t *driver, device_t parent)
84 {
85 phandle_t node;
86 uint32_t min_freq;
87
88 node = ofw_bus_get_node(parent);
89 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
90 return;
91
92 /* Make sure we're not being doubly invoked. */
93 if (device_find_child(parent, "pmufreq", -1) != NULL)
94 return;
95
96 /*
97 * We attach a child for every CPU since settings need to
98 * be performed on every CPU in the SMP case.
99 */
100 if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
101 device_printf(parent, "add pmufreq child failed\n");
102 }
103
104 static int
pmufreq_probe(device_t dev)105 pmufreq_probe(device_t dev)
106 {
107 phandle_t node;
108 uint32_t min_freq;
109
110 if (resource_disabled("pmufreq", 0))
111 return (ENXIO);
112
113 node = ofw_bus_get_node(device_get_parent(dev));
114 /*
115 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
116 * properties of the 'cpu' node.
117 */
118 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
119 return (ENXIO);
120 device_set_desc(dev, "PMU-based frequency scaling");
121 return (0);
122 }
123
124 static int
pmufreq_attach(device_t dev)125 pmufreq_attach(device_t dev)
126 {
127 struct pmufreq_softc *sc;
128 phandle_t node;
129
130 sc = device_get_softc(dev);
131 sc->dev = dev;
132
133 node = ofw_bus_get_node(device_get_parent(dev));
134 OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
135 OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
136 OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
137 sc->minfreq /= 1000000;
138 sc->maxfreq /= 1000000;
139 sc->curfreq /= 1000000;
140
141 cpufreq_register(dev);
142 return (0);
143 }
144
145 static int
pmufreq_settings(device_t dev,struct cf_setting * sets,int * count)146 pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
147 {
148 struct pmufreq_softc *sc;
149
150 sc = device_get_softc(dev);
151 if (sets == NULL || count == NULL)
152 return (EINVAL);
153 if (*count < 2)
154 return (E2BIG);
155
156 /* Return a list of valid settings for this driver. */
157 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
158
159 sets[0].freq = sc->maxfreq; sets[0].dev = dev;
160 sets[1].freq = sc->minfreq; sets[1].dev = dev;
161 /* Set high latency for CPU frequency changes, it's a tedious process. */
162 sets[0].lat = INT_MAX;
163 sets[1].lat = INT_MAX;
164 *count = 2;
165
166 return (0);
167 }
168
169 static int
pmufreq_set(device_t dev,const struct cf_setting * set)170 pmufreq_set(device_t dev, const struct cf_setting *set)
171 {
172 struct pmufreq_softc *sc;
173 int error, speed_sel;
174
175 if (set == NULL)
176 return (EINVAL);
177
178 sc = device_get_softc(dev);
179
180 if (set->freq == sc->maxfreq)
181 speed_sel = 0;
182 else
183 speed_sel = 1;
184
185 error = pmu_set_speed(speed_sel);
186 if (error == 0)
187 sc->curfreq = set->freq;
188
189 return (error);
190 }
191
192 static int
pmufreq_get(device_t dev,struct cf_setting * set)193 pmufreq_get(device_t dev, struct cf_setting *set)
194 {
195 struct pmufreq_softc *sc;
196
197 if (set == NULL)
198 return (EINVAL);
199 sc = device_get_softc(dev);
200
201 set->freq = sc->curfreq;
202 set->dev = dev;
203
204 return (0);
205 }
206
207 static int
pmufreq_type(device_t dev,int * type)208 pmufreq_type(device_t dev, int *type)
209 {
210
211 if (type == NULL)
212 return (EINVAL);
213
214 *type = CPUFREQ_TYPE_ABSOLUTE;
215 return (0);
216 }
217