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 static devclass_t pcr_devclass; 78 DRIVER_MODULE(pcr, cpu, pcr_driver, pcr_devclass, 0, 0); 79 80 /* 81 * States 82 */ 83 84 #define PCR_TO_FREQ(a) ((a >> 17) & 3) 85 86 #define PCR_FULL 0 87 #define PCR_HALF 1 88 #define PCR_QUARTER 2 /* Only on 970MP */ 89 90 #define PSR_RECEIVED (1ULL << 61) 91 #define PSR_COMPLETED (1ULL << 61) 92 93 /* 94 * SCOM addresses 95 */ 96 97 #define SCOM_PCR 0x0aa00100 /* Power Control Register */ 98 #define SCOM_PCR_BIT 0x80000000 /* Data bit for PCR */ 99 #define SCOM_PSR 0x40800100 /* Power Status Register */ 100 101 /* 102 * SCOM Glue 103 */ 104 105 #define SCOMC_READ 0x00008000 106 #define SCOMC_WRITE 0x00000000 107 108 static void 109 write_scom(register_t address, uint64_t value) 110 { 111 register_t msr; 112 #ifndef __powerpc64__ 113 register_t hi, lo, scratch; 114 #endif 115 116 msr = mfmsr(); 117 mtmsr(msr & ~PSL_EE); isync(); 118 119 #ifdef __powerpc64__ 120 mtspr(SPR_SCOMD, value); 121 #else 122 hi = (value >> 32) & 0xffffffff; 123 lo = value & 0xffffffff; 124 mtspr64(SPR_SCOMD, hi, lo, scratch); 125 #endif 126 isync(); 127 mtspr(SPR_SCOMC, address | SCOMC_WRITE); 128 isync(); 129 130 mtmsr(msr); isync(); 131 } 132 133 static uint64_t 134 read_scom(register_t address) 135 { 136 register_t msr; 137 uint64_t ret; 138 139 msr = mfmsr(); 140 mtmsr(msr & ~PSL_EE); isync(); 141 142 mtspr(SPR_SCOMC, address | SCOMC_READ); 143 isync(); 144 145 __asm __volatile ("mfspr %0,%1;" 146 " mr %0+1, %0; srdi %0,%0,32" : "=r" (ret) : "K" (SPR_SCOMD)); 147 148 (void)mfspr(SPR_SCOMC); /* Complete transcation */ 149 150 mtmsr(msr); isync(); 151 152 return (ret); 153 } 154 155 static void 156 pcr_identify(driver_t *driver, device_t parent) 157 { 158 uint16_t vers; 159 vers = mfpvr() >> 16; 160 161 /* Check for an IBM 970-class CPU */ 162 switch (vers) { 163 case IBM970FX: 164 case IBM970GX: 165 case IBM970MP: 166 break; 167 default: 168 return; 169 } 170 171 /* Make sure we're not being doubly invoked. */ 172 if (device_find_child(parent, "pcr", -1) != NULL) 173 return; 174 175 /* 176 * We attach a child for every CPU since settings need to 177 * be performed on every CPU in the SMP case. 178 */ 179 if (BUS_ADD_CHILD(parent, 10, "pcr", -1) == NULL) 180 device_printf(parent, "add pcr child failed\n"); 181 } 182 183 static int 184 pcr_probe(device_t dev) 185 { 186 if (resource_disabled("pcr", 0)) 187 return (ENXIO); 188 189 device_set_desc(dev, "PPC 970 Power Control Register"); 190 return (0); 191 } 192 193 static int 194 pcr_attach(device_t dev) 195 { 196 struct pcr_softc *sc; 197 phandle_t cpu; 198 uint32_t modes[3]; 199 int i; 200 201 sc = device_get_softc(dev); 202 sc->dev = dev; 203 204 cpu = ofw_bus_get_node(device_get_parent(dev)); 205 206 if (cpu <= 0) { 207 device_printf(dev,"No CPU device tree node!\n"); 208 return (ENXIO); 209 } 210 211 if (OF_getproplen(cpu, "power-mode-data") <= 0) { 212 /* Use the first CPU's node */ 213 cpu = OF_child(OF_parent(cpu)); 214 } 215 216 /* 217 * Collect the PCR values for each mode from the device tree. 218 * These include bus timing information, and so cannot be 219 * directly computed. 220 */ 221 sc->nmodes = OF_getproplen(cpu, "power-mode-data"); 222 if (sc->nmodes <= 0 || sc->nmodes > sizeof(sc->pcr_vals)) { 223 device_printf(dev,"No power mode data in device tree!\n"); 224 return (ENXIO); 225 } 226 OF_getprop(cpu, "power-mode-data", modes, sc->nmodes); 227 sc->nmodes /= sizeof(modes[0]); 228 229 /* Sort the modes */ 230 for (i = 0; i < sc->nmodes; i++) 231 sc->pcr_vals[PCR_TO_FREQ(modes[i])] = modes[i]; 232 233 cpufreq_register(dev); 234 return (0); 235 } 236 237 static int 238 pcr_settings(device_t dev, struct cf_setting *sets, int *count) 239 { 240 struct pcr_softc *sc; 241 242 sc = device_get_softc(dev); 243 if (sets == NULL || count == NULL) 244 return (EINVAL); 245 if (*count < sc->nmodes) 246 return (E2BIG); 247 248 /* Return a list of valid settings for this driver. */ 249 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->nmodes); 250 251 sets[0].freq = 10000; sets[0].dev = dev; 252 sets[1].freq = 5000; sets[1].dev = dev; 253 if (sc->nmodes > 2) { 254 sets[2].freq = 2500; 255 sets[2].dev = dev; 256 } 257 *count = sc->nmodes; 258 259 return (0); 260 } 261 262 static int 263 pcr_set(device_t dev, const struct cf_setting *set) 264 { 265 struct pcr_softc *sc; 266 register_t pcr, msr; 267 uint64_t psr; 268 269 if (set == NULL) 270 return (EINVAL); 271 sc = device_get_softc(dev); 272 273 /* Construct the new PCR */ 274 275 pcr = SCOM_PCR_BIT; 276 277 if (set->freq == 10000) 278 pcr |= sc->pcr_vals[0]; 279 else if (set->freq == 5000) 280 pcr |= sc->pcr_vals[1]; 281 else if (set->freq == 2500) 282 pcr |= sc->pcr_vals[2]; 283 284 msr = mfmsr(); 285 mtmsr(msr & ~PSL_EE); isync(); 286 287 /* 970MP requires PCR and PCRH to be cleared first */ 288 289 write_scom(SCOM_PCR,0); /* Clear PCRH */ 290 write_scom(SCOM_PCR,SCOM_PCR_BIT); /* Clear PCR */ 291 292 /* Set PCR */ 293 294 write_scom(SCOM_PCR, pcr); 295 296 /* Wait for completion */ 297 298 do { 299 DELAY(100); 300 psr = read_scom(SCOM_PSR); 301 } while ((psr & PSR_RECEIVED) && !(psr & PSR_COMPLETED)); 302 303 mtmsr(msr); isync(); 304 305 return (0); 306 } 307 308 static int 309 pcr_get(device_t dev, struct cf_setting *set) 310 { 311 uint64_t psr; 312 313 if (set == NULL) 314 return (EINVAL); 315 316 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 317 318 psr = read_scom(SCOM_PSR); 319 320 /* We want bits 6 and 7 */ 321 psr = (psr >> 56) & 3; 322 323 set->freq = 10000; 324 if (psr == PCR_HALF) 325 set->freq = 5000; 326 else if (psr == PCR_QUARTER) 327 set->freq = 2500; 328 329 set->dev = dev; 330 331 return (0); 332 } 333 334 static int 335 pcr_type(device_t dev, int *type) 336 { 337 338 if (type == NULL) 339 return (EINVAL); 340 341 *type = CPUFREQ_TYPE_RELATIVE; 342 return (0); 343 } 344