1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2009 Nathan Whitehorn 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/bus.h> 35 #include <sys/cpu.h> 36 #include <sys/kernel.h> 37 #include <sys/module.h> 38 39 #include <dev/ofw/ofw_bus.h> 40 41 #include "cpufreq_if.h" 42 43 struct pcr_softc { 44 device_t dev; 45 uint32_t pcr_vals[3]; 46 int nmodes; 47 }; 48 49 static void pcr_identify(driver_t *driver, device_t parent); 50 static int pcr_probe(device_t dev); 51 static int pcr_attach(device_t dev); 52 static int pcr_settings(device_t dev, struct cf_setting *sets, int *count); 53 static int pcr_set(device_t dev, const struct cf_setting *set); 54 static int pcr_get(device_t dev, struct cf_setting *set); 55 static int pcr_type(device_t dev, int *type); 56 57 static device_method_t pcr_methods[] = { 58 /* Device interface */ 59 DEVMETHOD(device_identify, pcr_identify), 60 DEVMETHOD(device_probe, pcr_probe), 61 DEVMETHOD(device_attach, pcr_attach), 62 63 /* cpufreq interface */ 64 DEVMETHOD(cpufreq_drv_set, pcr_set), 65 DEVMETHOD(cpufreq_drv_get, pcr_get), 66 DEVMETHOD(cpufreq_drv_type, pcr_type), 67 DEVMETHOD(cpufreq_drv_settings, pcr_settings), 68 {0, 0} 69 }; 70 71 static driver_t pcr_driver = { 72 "pcr", 73 pcr_methods, 74 sizeof(struct pcr_softc) 75 }; 76 77 DRIVER_MODULE(pcr, cpu, pcr_driver, 0, 0); 78 79 /* 80 * States 81 */ 82 83 #define PCR_TO_FREQ(a) ((a >> 17) & 3) 84 85 #define PCR_FULL 0 86 #define PCR_HALF 1 87 #define PCR_QUARTER 2 /* Only on 970MP */ 88 89 #define PSR_RECEIVED (1ULL << 61) 90 #define PSR_COMPLETED (1ULL << 61) 91 92 /* 93 * SCOM addresses 94 */ 95 96 #define SCOM_PCR 0x0aa00100 /* Power Control Register */ 97 #define SCOM_PCR_BIT 0x80000000 /* Data bit for PCR */ 98 #define SCOM_PSR 0x40800100 /* Power Status Register */ 99 100 /* 101 * SCOM Glue 102 */ 103 104 #define SCOMC_READ 0x00008000 105 #define SCOMC_WRITE 0x00000000 106 107 static void 108 write_scom(register_t address, uint64_t value) 109 { 110 register_t msr; 111 #ifndef __powerpc64__ 112 register_t hi, lo, scratch; 113 #endif 114 115 msr = mfmsr(); 116 mtmsr(msr & ~PSL_EE); isync(); 117 118 #ifdef __powerpc64__ 119 mtspr(SPR_SCOMD, value); 120 #else 121 hi = (value >> 32) & 0xffffffff; 122 lo = value & 0xffffffff; 123 mtspr64(SPR_SCOMD, hi, lo, scratch); 124 #endif 125 isync(); 126 mtspr(SPR_SCOMC, address | SCOMC_WRITE); 127 isync(); 128 129 mtmsr(msr); isync(); 130 } 131 132 static uint64_t 133 read_scom(register_t address) 134 { 135 register_t msr; 136 uint64_t ret; 137 138 msr = mfmsr(); 139 mtmsr(msr & ~PSL_EE); isync(); 140 141 mtspr(SPR_SCOMC, address | SCOMC_READ); 142 isync(); 143 144 __asm __volatile ("mfspr %0,%1;" 145 " mr %0+1, %0; srdi %0,%0,32" : "=r" (ret) : "K" (SPR_SCOMD)); 146 147 (void)mfspr(SPR_SCOMC); /* Complete transcation */ 148 149 mtmsr(msr); isync(); 150 151 return (ret); 152 } 153 154 static void 155 pcr_identify(driver_t *driver, device_t parent) 156 { 157 uint16_t vers; 158 vers = mfpvr() >> 16; 159 160 /* Check for an IBM 970-class CPU */ 161 switch (vers) { 162 case IBM970FX: 163 case IBM970GX: 164 case IBM970MP: 165 break; 166 default: 167 return; 168 } 169 170 /* Make sure we're not being doubly invoked. */ 171 if (device_find_child(parent, "pcr", -1) != NULL) 172 return; 173 174 /* 175 * We attach a child for every CPU since settings need to 176 * be performed on every CPU in the SMP case. 177 */ 178 if (BUS_ADD_CHILD(parent, 10, "pcr", -1) == NULL) 179 device_printf(parent, "add pcr child failed\n"); 180 } 181 182 static int 183 pcr_probe(device_t dev) 184 { 185 if (resource_disabled("pcr", 0)) 186 return (ENXIO); 187 188 device_set_desc(dev, "PPC 970 Power Control Register"); 189 return (0); 190 } 191 192 static int 193 pcr_attach(device_t dev) 194 { 195 struct pcr_softc *sc; 196 phandle_t cpu; 197 uint32_t modes[3]; 198 int i; 199 200 sc = device_get_softc(dev); 201 sc->dev = dev; 202 203 cpu = ofw_bus_get_node(device_get_parent(dev)); 204 205 if (cpu <= 0) { 206 device_printf(dev,"No CPU device tree node!\n"); 207 return (ENXIO); 208 } 209 210 if (OF_getproplen(cpu, "power-mode-data") <= 0) { 211 /* Use the first CPU's node */ 212 cpu = OF_child(OF_parent(cpu)); 213 } 214 215 /* 216 * Collect the PCR values for each mode from the device tree. 217 * These include bus timing information, and so cannot be 218 * directly computed. 219 */ 220 sc->nmodes = OF_getproplen(cpu, "power-mode-data"); 221 if (sc->nmodes <= 0 || sc->nmodes > sizeof(sc->pcr_vals)) { 222 device_printf(dev,"No power mode data in device tree!\n"); 223 return (ENXIO); 224 } 225 OF_getprop(cpu, "power-mode-data", modes, sc->nmodes); 226 sc->nmodes /= sizeof(modes[0]); 227 228 /* Sort the modes */ 229 for (i = 0; i < sc->nmodes; i++) 230 sc->pcr_vals[PCR_TO_FREQ(modes[i])] = modes[i]; 231 232 cpufreq_register(dev); 233 return (0); 234 } 235 236 static int 237 pcr_settings(device_t dev, struct cf_setting *sets, int *count) 238 { 239 struct pcr_softc *sc; 240 241 sc = device_get_softc(dev); 242 if (sets == NULL || count == NULL) 243 return (EINVAL); 244 if (*count < sc->nmodes) 245 return (E2BIG); 246 247 /* Return a list of valid settings for this driver. */ 248 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->nmodes); 249 250 sets[0].freq = 10000; sets[0].dev = dev; 251 sets[1].freq = 5000; sets[1].dev = dev; 252 if (sc->nmodes > 2) { 253 sets[2].freq = 2500; 254 sets[2].dev = dev; 255 } 256 *count = sc->nmodes; 257 258 return (0); 259 } 260 261 static int 262 pcr_set(device_t dev, const struct cf_setting *set) 263 { 264 struct pcr_softc *sc; 265 register_t pcr, msr; 266 uint64_t psr; 267 268 if (set == NULL) 269 return (EINVAL); 270 sc = device_get_softc(dev); 271 272 /* Construct the new PCR */ 273 274 pcr = SCOM_PCR_BIT; 275 276 if (set->freq == 10000) 277 pcr |= sc->pcr_vals[0]; 278 else if (set->freq == 5000) 279 pcr |= sc->pcr_vals[1]; 280 else if (set->freq == 2500) 281 pcr |= sc->pcr_vals[2]; 282 283 msr = mfmsr(); 284 mtmsr(msr & ~PSL_EE); isync(); 285 286 /* 970MP requires PCR and PCRH to be cleared first */ 287 288 write_scom(SCOM_PCR,0); /* Clear PCRH */ 289 write_scom(SCOM_PCR,SCOM_PCR_BIT); /* Clear PCR */ 290 291 /* Set PCR */ 292 293 write_scom(SCOM_PCR, pcr); 294 295 /* Wait for completion */ 296 297 do { 298 DELAY(100); 299 psr = read_scom(SCOM_PSR); 300 } while ((psr & PSR_RECEIVED) && !(psr & PSR_COMPLETED)); 301 302 mtmsr(msr); isync(); 303 304 return (0); 305 } 306 307 static int 308 pcr_get(device_t dev, struct cf_setting *set) 309 { 310 uint64_t psr; 311 312 if (set == NULL) 313 return (EINVAL); 314 315 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 316 317 psr = read_scom(SCOM_PSR); 318 319 /* We want bits 6 and 7 */ 320 psr = (psr >> 56) & 3; 321 322 set->freq = 10000; 323 if (psr == PCR_HALF) 324 set->freq = 5000; 325 else if (psr == PCR_QUARTER) 326 set->freq = 2500; 327 328 set->dev = dev; 329 330 return (0); 331 } 332 333 static int 334 pcr_type(device_t dev, int *type) 335 { 336 337 if (type == NULL) 338 return (EINVAL); 339 340 *type = CPUFREQ_TYPE_RELATIVE; 341 return (0); 342 } 343