pmufreq.c revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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__FBSDID("$FreeBSD: stable/11/sys/powerpc/cpufreq/pmufreq.c 330897 2018-03-14 03:19:51Z eadler $"); 32 33#include <sys/param.h> 34#include <sys/systm.h> 35#include <sys/bus.h> 36#include <sys/cpu.h> 37#include <sys/kernel.h> 38#include <sys/limits.h> 39#include <sys/module.h> 40 41#include <dev/ofw/ofw_bus.h> 42#include <dev/ofw/openfirm.h> 43 44#include "cpufreq_if.h" 45#include "powerpc/powermac/pmuvar.h" 46 47struct pmufreq_softc { 48 device_t dev; 49 uint32_t minfreq; 50 uint32_t maxfreq; 51 uint32_t curfreq; 52}; 53 54static void pmufreq_identify(driver_t *driver, device_t parent); 55static int pmufreq_probe(device_t dev); 56static int pmufreq_attach(device_t dev); 57static int pmufreq_settings(device_t dev, struct cf_setting *sets, int *count); 58static int pmufreq_set(device_t dev, const struct cf_setting *set); 59static int pmufreq_get(device_t dev, struct cf_setting *set); 60static int pmufreq_type(device_t dev, int *type); 61 62static device_method_t pmufreq_methods[] = { 63 /* Device interface */ 64 DEVMETHOD(device_identify, pmufreq_identify), 65 DEVMETHOD(device_probe, pmufreq_probe), 66 DEVMETHOD(device_attach, pmufreq_attach), 67 68 /* cpufreq interface */ 69 DEVMETHOD(cpufreq_drv_set, pmufreq_set), 70 DEVMETHOD(cpufreq_drv_get, pmufreq_get), 71 DEVMETHOD(cpufreq_drv_type, pmufreq_type), 72 DEVMETHOD(cpufreq_drv_settings, pmufreq_settings), 73 74 {0, 0} 75}; 76 77static driver_t pmufreq_driver = { 78 "pmufreq", 79 pmufreq_methods, 80 sizeof(struct pmufreq_softc) 81}; 82 83static devclass_t pmufreq_devclass; 84DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, pmufreq_devclass, 0, 0); 85 86static void 87pmufreq_identify(driver_t *driver, device_t parent) 88{ 89 phandle_t node; 90 uint32_t min_freq; 91 92 node = ofw_bus_get_node(parent); 93 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1) 94 return; 95 96 /* Make sure we're not being doubly invoked. */ 97 if (device_find_child(parent, "pmufreq", -1) != NULL) 98 return; 99 100 /* 101 * We attach a child for every CPU since settings need to 102 * be performed on every CPU in the SMP case. 103 */ 104 if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL) 105 device_printf(parent, "add pmufreq child failed\n"); 106} 107 108static int 109pmufreq_probe(device_t dev) 110{ 111 struct pmufreq_softc *sc; 112 phandle_t node; 113 uint32_t min_freq; 114 115 if (resource_disabled("pmufreq", 0)) 116 return (ENXIO); 117 118 sc = device_get_softc(dev); 119 node = ofw_bus_get_node(device_get_parent(dev)); 120 /* 121 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW 122 * properties of the 'cpu' node. 123 */ 124 if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1) 125 return (ENXIO); 126 device_set_desc(dev, "PMU-based frequency scaling"); 127 return (0); 128} 129 130static int 131pmufreq_attach(device_t dev) 132{ 133 struct pmufreq_softc *sc; 134 phandle_t node; 135 136 sc = device_get_softc(dev); 137 sc->dev = dev; 138 139 node = ofw_bus_get_node(device_get_parent(dev)); 140 OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq)); 141 OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq)); 142 OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq)); 143 sc->minfreq /= 1000000; 144 sc->maxfreq /= 1000000; 145 sc->curfreq /= 1000000; 146 147 cpufreq_register(dev); 148 return (0); 149} 150 151static int 152pmufreq_settings(device_t dev, struct cf_setting *sets, int *count) 153{ 154 struct pmufreq_softc *sc; 155 156 sc = device_get_softc(dev); 157 if (sets == NULL || count == NULL) 158 return (EINVAL); 159 if (*count < 2) 160 return (E2BIG); 161 162 /* Return a list of valid settings for this driver. */ 163 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2); 164 165 sets[0].freq = sc->maxfreq; sets[0].dev = dev; 166 sets[1].freq = sc->minfreq; sets[1].dev = dev; 167 /* Set high latency for CPU frequency changes, it's a tedious process. */ 168 sets[0].lat = INT_MAX; 169 sets[1].lat = INT_MAX; 170 *count = 2; 171 172 return (0); 173} 174 175static int 176pmufreq_set(device_t dev, const struct cf_setting *set) 177{ 178 struct pmufreq_softc *sc; 179 int error, speed_sel; 180 181 if (set == NULL) 182 return (EINVAL); 183 184 sc = device_get_softc(dev); 185 186 if (set->freq == sc->maxfreq) 187 speed_sel = 0; 188 else 189 speed_sel = 1; 190 191 error = pmu_set_speed(speed_sel); 192 if (error == 0) 193 sc->curfreq = set->freq; 194 195 return (error); 196} 197 198static int 199pmufreq_get(device_t dev, struct cf_setting *set) 200{ 201 struct pmufreq_softc *sc; 202 203 if (set == NULL) 204 return (EINVAL); 205 sc = device_get_softc(dev); 206 207 set->freq = sc->curfreq; 208 set->dev = dev; 209 210 return (0); 211} 212 213static int 214pmufreq_type(device_t dev, int *type) 215{ 216 217 if (type == NULL) 218 return (EINVAL); 219 220 *type = CPUFREQ_TYPE_ABSOLUTE; 221 return (0); 222} 223 224