1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2018 Justin Hibbits
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 #include <sys/cpu.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34
35 #include <dev/ofw/openfirm.h>
36
37 #include "cpufreq_if.h"
38
39 static int pstate_ids[256];
40 static int pstate_freqs[256];
41 static int npstates;
42
43 static void
parse_pstates(void * dummy __unused)44 parse_pstates(void *dummy __unused)
45 {
46 phandle_t node;
47
48 node = OF_finddevice("/ibm,opal/power-mgt");
49
50 /* If this fails, npstates will remain 0, and any attachment will bail. */
51 if (node == -1)
52 return;
53
54 npstates = OF_getencprop(node, "ibm,pstate-ids", pstate_ids,
55 sizeof(pstate_ids));
56 if (npstates < 0) {
57 npstates = 0;
58 return;
59 }
60
61 if (OF_getencprop(node, "ibm,pstate-frequencies-mhz", pstate_freqs,
62 sizeof(pstate_freqs)) != npstates) {
63 npstates = 0;
64 return;
65 }
66 npstates /= sizeof(cell_t);
67
68 }
69
70 /* Make this a sysinit so it runs before the cpufreq driver attaches. */
71 SYSINIT(parse_pstates, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, parse_pstates, NULL);
72
73 #define PMCR_UPPERPS_MASK 0xff00000000000000UL
74 #define PMCR_UPPERPS_SHIFT 56
75 #define PMCR_LOWERPS_MASK 0x00ff000000000000UL
76 #define PMCR_LOWERPS_SHIFT 48
77 #define PMCR_VERSION_MASK 0x0000000f
78 #define PMCR_VERSION_1 1
79
80 struct pmcr_softc {
81 device_t dev;
82 };
83
84 static void pmcr_identify(driver_t *driver, device_t parent);
85 static int pmcr_probe(device_t dev);
86 static int pmcr_attach(device_t dev);
87 static int pmcr_settings(device_t dev, struct cf_setting *sets, int *count);
88 static int pmcr_set(device_t dev, const struct cf_setting *set);
89 static int pmcr_get(device_t dev, struct cf_setting *set);
90 static int pmcr_type(device_t dev, int *type);
91
92 static device_method_t pmcr_methods[] = {
93 /* Device interface */
94 DEVMETHOD(device_identify, pmcr_identify),
95 DEVMETHOD(device_probe, pmcr_probe),
96 DEVMETHOD(device_attach, pmcr_attach),
97
98 /* cpufreq interface */
99 DEVMETHOD(cpufreq_drv_set, pmcr_set),
100 DEVMETHOD(cpufreq_drv_get, pmcr_get),
101 DEVMETHOD(cpufreq_drv_type, pmcr_type),
102 DEVMETHOD(cpufreq_drv_settings, pmcr_settings),
103 {0, 0}
104 };
105
106 static driver_t pmcr_driver = {
107 "pmcr",
108 pmcr_methods,
109 sizeof(struct pmcr_softc)
110 };
111
112 DRIVER_MODULE(pmcr, cpu, pmcr_driver, 0, 0);
113
114 static void
pmcr_identify(driver_t * driver,device_t parent)115 pmcr_identify(driver_t *driver, device_t parent)
116 {
117
118 /* Make sure we're not being doubly invoked. */
119 if (device_find_child(parent, "pmcr", DEVICE_UNIT_ANY) != NULL)
120 return;
121
122 /*
123 * We attach a child for every CPU since settings need to
124 * be performed on every CPU in the SMP case.
125 */
126 if (BUS_ADD_CHILD(parent, 10, "pmcr", DEVICE_UNIT_ANY) == NULL)
127 device_printf(parent, "add pmcr child failed\n");
128 }
129
130 static int
pmcr_probe(device_t dev)131 pmcr_probe(device_t dev)
132 {
133 if (resource_disabled("pmcr", 0))
134 return (ENXIO);
135
136 if (npstates == 0)
137 return (ENXIO);
138
139 device_set_desc(dev, "Power Management Control Register");
140 return (0);
141 }
142
143 static int
pmcr_attach(device_t dev)144 pmcr_attach(device_t dev)
145 {
146 struct pmcr_softc *sc;
147
148 sc = device_get_softc(dev);
149 sc->dev = dev;
150
151 cpufreq_register(dev);
152 return (0);
153 }
154
155 static int
pmcr_settings(device_t dev,struct cf_setting * sets,int * count)156 pmcr_settings(device_t dev, struct cf_setting *sets, int *count)
157 {
158 int i;
159
160 if (sets == NULL || count == NULL)
161 return (EINVAL);
162 if (*count < npstates)
163 return (E2BIG);
164
165 /* Return a list of valid settings for this driver. */
166 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * npstates);
167
168 for (i = 0; i < npstates; i++) {
169 sets[i].freq = pstate_freqs[i];
170 sets[i].spec[0] = pstate_ids[i];
171 sets[i].spec[1] = i;
172 sets[i].dev = dev;
173 }
174 *count = npstates;
175
176 return (0);
177 }
178
179 static int
pmcr_set(device_t dev,const struct cf_setting * set)180 pmcr_set(device_t dev, const struct cf_setting *set)
181 {
182 register_t pmcr;
183
184 if (set == NULL)
185 return (EINVAL);
186
187 if (set->spec[1] < 0 || set->spec[1] >= npstates)
188 return (EINVAL);
189
190 pmcr = ((long)set->spec[0] << PMCR_LOWERPS_SHIFT) & PMCR_LOWERPS_MASK;
191 pmcr |= ((long)set->spec[0] << PMCR_UPPERPS_SHIFT) & PMCR_UPPERPS_MASK;
192 pmcr |= PMCR_VERSION_1;
193
194 mtspr(SPR_PMCR, pmcr);
195 powerpc_sync(); isync();
196
197 return (0);
198 }
199
200 static int
pmcr_get(device_t dev,struct cf_setting * set)201 pmcr_get(device_t dev, struct cf_setting *set)
202 {
203 register_t pmcr;
204 int i, pstate;
205
206 if (set == NULL)
207 return (EINVAL);
208
209 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
210
211 pmcr = mfspr(SPR_PMCR);
212
213 pstate = (pmcr & PMCR_LOWERPS_MASK) >> PMCR_LOWERPS_SHIFT;
214
215 for (i = 0; i < npstates && pstate_ids[i] != pstate; i++)
216 ;
217
218 if (i == npstates)
219 return (EINVAL);
220
221 set->spec[0] = pstate;
222 set->spec[1] = i;
223 set->freq = pstate_freqs[i];
224
225 set->dev = dev;
226
227 return (0);
228 }
229
230 static int
pmcr_type(device_t dev,int * type)231 pmcr_type(device_t dev, int *type)
232 {
233
234 if (type == NULL)
235 return (EINVAL);
236
237 *type = CPUFREQ_TYPE_ABSOLUTE;
238 return (0);
239 }
240