1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/cdefs.h> 29__FBSDID("$FreeBSD$"); 30 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/module.h> 37 38#include <dev/ofw/openfirm.h> 39 40#include "cpufreq_if.h" 41 42static int pstate_ids[256]; 43static int pstate_freqs[256]; 44static int npstates; 45 46static void parse_pstates(void) 47{ 48 phandle_t node; 49 50 node = OF_finddevice("/ibm,opal/power-mgt"); 51 52 /* If this fails, npstates will remain 0, and any attachment will bail. */ 53 if (node == -1) 54 return; 55 56 npstates = OF_getencprop(node, "ibm,pstate-ids", pstate_ids, 57 sizeof(pstate_ids)); 58 if (npstates < 0) { 59 npstates = 0; 60 return; 61 } 62 63 if (OF_getencprop(node, "ibm,pstate-frequencies-mhz", pstate_freqs, 64 sizeof(pstate_freqs)) != npstates) { 65 npstates = 0; 66 return; 67 } 68 npstates /= sizeof(cell_t); 69 70} 71 72/* Make this a sysinit so it runs before the cpufreq driver attaches. */ 73SYSINIT(parse_pstates, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, parse_pstates, NULL); 74 75#define PMCR_UPPERPS_MASK 0xff00000000000000UL 76#define PMCR_UPPERPS_SHIFT 56 77#define PMCR_LOWERPS_MASK 0x00ff000000000000UL 78#define PMCR_LOWERPS_SHIFT 48 79#define PMCR_VERSION_MASK 0x0000000f 80#define PMCR_VERSION_1 1 81 82struct pmcr_softc { 83 device_t dev; 84}; 85 86static void pmcr_identify(driver_t *driver, device_t parent); 87static int pmcr_probe(device_t dev); 88static int pmcr_attach(device_t dev); 89static int pmcr_settings(device_t dev, struct cf_setting *sets, int *count); 90static int pmcr_set(device_t dev, const struct cf_setting *set); 91static int pmcr_get(device_t dev, struct cf_setting *set); 92static int pmcr_type(device_t dev, int *type); 93 94static device_method_t pmcr_methods[] = { 95 /* Device interface */ 96 DEVMETHOD(device_identify, pmcr_identify), 97 DEVMETHOD(device_probe, pmcr_probe), 98 DEVMETHOD(device_attach, pmcr_attach), 99 100 /* cpufreq interface */ 101 DEVMETHOD(cpufreq_drv_set, pmcr_set), 102 DEVMETHOD(cpufreq_drv_get, pmcr_get), 103 DEVMETHOD(cpufreq_drv_type, pmcr_type), 104 DEVMETHOD(cpufreq_drv_settings, pmcr_settings), 105 {0, 0} 106}; 107 108static driver_t pmcr_driver = { 109 "pmcr", 110 pmcr_methods, 111 sizeof(struct pmcr_softc) 112}; 113 114static devclass_t pmcr_devclass; 115DRIVER_MODULE(pmcr, cpu, pmcr_driver, pmcr_devclass, 0, 0); 116 117static void 118pmcr_identify(driver_t *driver, device_t parent) 119{ 120 121 /* Make sure we're not being doubly invoked. */ 122 if (device_find_child(parent, "pmcr", -1) != NULL) 123 return; 124 125 /* 126 * We attach a child for every CPU since settings need to 127 * be performed on every CPU in the SMP case. 128 */ 129 if (BUS_ADD_CHILD(parent, 10, "pmcr", -1) == NULL) 130 device_printf(parent, "add pmcr child failed\n"); 131} 132 133static int 134pmcr_probe(device_t dev) 135{ 136 if (resource_disabled("pmcr", 0)) 137 return (ENXIO); 138 139 if (npstates == 0) 140 return (ENXIO); 141 142 device_set_desc(dev, "Power Management Control Register"); 143 return (0); 144} 145 146static int 147pmcr_attach(device_t dev) 148{ 149 struct pmcr_softc *sc; 150 151 sc = device_get_softc(dev); 152 sc->dev = dev; 153 154 cpufreq_register(dev); 155 return (0); 156} 157 158static int 159pmcr_settings(device_t dev, struct cf_setting *sets, int *count) 160{ 161 struct pmcr_softc *sc; 162 int i; 163 164 sc = device_get_softc(dev); 165 if (sets == NULL || count == NULL) 166 return (EINVAL); 167 if (*count < npstates) 168 return (E2BIG); 169 170 /* Return a list of valid settings for this driver. */ 171 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * npstates); 172 173 for (i = 0; i < npstates; i++) { 174 sets[i].freq = pstate_freqs[i]; 175 sets[i].spec[0] = pstate_ids[i]; 176 sets[i].spec[1] = i; 177 sets[i].dev = dev; 178 } 179 *count = npstates; 180 181 return (0); 182} 183 184static int 185pmcr_set(device_t dev, const struct cf_setting *set) 186{ 187 register_t pmcr; 188 189 if (set == NULL) 190 return (EINVAL); 191 192 if (set->spec[1] < 0 || set->spec[1] >= npstates) 193 return (EINVAL); 194 195 pmcr = ((long)set->spec[0] << PMCR_LOWERPS_SHIFT) & PMCR_LOWERPS_MASK; 196 pmcr |= ((long)set->spec[0] << PMCR_UPPERPS_SHIFT) & PMCR_UPPERPS_MASK; 197 pmcr |= PMCR_VERSION_1; 198 199 mtspr(SPR_PMCR, pmcr); 200 powerpc_sync(); isync(); 201 202 return (0); 203} 204 205static int 206pmcr_get(device_t dev, struct cf_setting *set) 207{ 208 struct pmcr_softc *sc; 209 register_t pmcr; 210 int i, pstate; 211 212 if (set == NULL) 213 return (EINVAL); 214 sc = device_get_softc(dev); 215 216 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 217 218 pmcr = mfspr(SPR_PMCR); 219 220 pstate = (pmcr & PMCR_LOWERPS_MASK) >> PMCR_LOWERPS_SHIFT; 221 222 for (i = 0; i < npstates && pstate_ids[i] != pstate; i++) 223 ; 224 225 if (i == npstates) 226 return (EINVAL); 227 228 set->spec[0] = pstate; 229 set->spec[1] = i; 230 set->freq = pstate_freqs[i]; 231 232 set->dev = dev; 233 234 return (0); 235} 236 237static int 238pmcr_type(device_t dev, int *type) 239{ 240 241 if (type == NULL) 242 return (EINVAL); 243 244 *type = CPUFREQ_TYPE_ABSOLUTE; 245 return (0); 246} 247