1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 30 #include <sys/systm.h> 31 #include <sys/bus.h> 32 #include <sys/cpu.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 36 #include <dev/ofw/ofw_bus.h> 37 38 #include "cpufreq_if.h" 39 40 struct pcr_softc { 41 device_t dev; 42 uint32_t pcr_vals[3]; 43 int nmodes; 44 }; 45 46 static void pcr_identify(driver_t *driver, device_t parent); 47 static int pcr_probe(device_t dev); 48 static int pcr_attach(device_t dev); 49 static int pcr_settings(device_t dev, struct cf_setting *sets, int *count); 50 static int pcr_set(device_t dev, const struct cf_setting *set); 51 static int pcr_get(device_t dev, struct cf_setting *set); 52 static int pcr_type(device_t dev, int *type); 53 54 static device_method_t pcr_methods[] = { 55 /* Device interface */ 56 DEVMETHOD(device_identify, pcr_identify), 57 DEVMETHOD(device_probe, pcr_probe), 58 DEVMETHOD(device_attach, pcr_attach), 59 60 /* cpufreq interface */ 61 DEVMETHOD(cpufreq_drv_set, pcr_set), 62 DEVMETHOD(cpufreq_drv_get, pcr_get), 63 DEVMETHOD(cpufreq_drv_type, pcr_type), 64 DEVMETHOD(cpufreq_drv_settings, pcr_settings), 65 {0, 0} 66 }; 67 68 static driver_t pcr_driver = { 69 "pcr", 70 pcr_methods, 71 sizeof(struct pcr_softc) 72 }; 73 74 DRIVER_MODULE(pcr, cpu, pcr_driver, 0, 0); 75 76 /* 77 * States 78 */ 79 80 #define PCR_TO_FREQ(a) ((a >> 17) & 3) 81 82 #define PCR_FULL 0 83 #define PCR_HALF 1 84 #define PCR_QUARTER 2 /* Only on 970MP */ 85 86 #define PSR_RECEIVED (1ULL << 61) 87 #define PSR_COMPLETED (1ULL << 61) 88 89 /* 90 * SCOM addresses 91 */ 92 93 #define SCOM_PCR 0x0aa00100 /* Power Control Register */ 94 #define SCOM_PCR_BIT 0x80000000 /* Data bit for PCR */ 95 #define SCOM_PSR 0x40800100 /* Power Status Register */ 96 97 /* 98 * SCOM Glue 99 */ 100 101 #define SCOMC_READ 0x00008000 102 #define SCOMC_WRITE 0x00000000 103 104 static void 105 write_scom(register_t address, uint64_t value) 106 { 107 register_t msr; 108 #ifndef __powerpc64__ 109 register_t hi, lo, scratch; 110 #endif 111 112 msr = mfmsr(); 113 mtmsr(msr & ~PSL_EE); isync(); 114 115 #ifdef __powerpc64__ 116 mtspr(SPR_SCOMD, value); 117 #else 118 hi = (value >> 32) & 0xffffffff; 119 lo = value & 0xffffffff; 120 mtspr64(SPR_SCOMD, hi, lo, scratch); 121 #endif 122 isync(); 123 mtspr(SPR_SCOMC, address | SCOMC_WRITE); 124 isync(); 125 126 mtmsr(msr); isync(); 127 } 128 129 static uint64_t 130 read_scom(register_t address) 131 { 132 register_t msr; 133 uint64_t ret; 134 135 msr = mfmsr(); 136 mtmsr(msr & ~PSL_EE); isync(); 137 138 mtspr(SPR_SCOMC, address | SCOMC_READ); 139 isync(); 140 141 __asm __volatile ("mfspr %0,%1;" 142 " mr %0+1, %0; srdi %0,%0,32" : "=r" (ret) : "K" (SPR_SCOMD)); 143 144 (void)mfspr(SPR_SCOMC); /* Complete transcation */ 145 146 mtmsr(msr); isync(); 147 148 return (ret); 149 } 150 151 static void 152 pcr_identify(driver_t *driver, device_t parent) 153 { 154 uint16_t vers; 155 vers = mfpvr() >> 16; 156 157 /* Check for an IBM 970-class CPU */ 158 switch (vers) { 159 case IBM970FX: 160 case IBM970GX: 161 case IBM970MP: 162 break; 163 default: 164 return; 165 } 166 167 /* Make sure we're not being doubly invoked. */ 168 if (device_find_child(parent, "pcr", -1) != NULL) 169 return; 170 171 /* 172 * We attach a child for every CPU since settings need to 173 * be performed on every CPU in the SMP case. 174 */ 175 if (BUS_ADD_CHILD(parent, 10, "pcr", -1) == NULL) 176 device_printf(parent, "add pcr child failed\n"); 177 } 178 179 static int 180 pcr_probe(device_t dev) 181 { 182 if (resource_disabled("pcr", 0)) 183 return (ENXIO); 184 185 device_set_desc(dev, "PPC 970 Power Control Register"); 186 return (0); 187 } 188 189 static int 190 pcr_attach(device_t dev) 191 { 192 struct pcr_softc *sc; 193 phandle_t cpu; 194 uint32_t modes[3]; 195 int i; 196 197 sc = device_get_softc(dev); 198 sc->dev = dev; 199 200 cpu = ofw_bus_get_node(device_get_parent(dev)); 201 202 if (cpu <= 0) { 203 device_printf(dev,"No CPU device tree node!\n"); 204 return (ENXIO); 205 } 206 207 if (OF_getproplen(cpu, "power-mode-data") <= 0) { 208 /* Use the first CPU's node */ 209 cpu = OF_child(OF_parent(cpu)); 210 } 211 212 /* 213 * Collect the PCR values for each mode from the device tree. 214 * These include bus timing information, and so cannot be 215 * directly computed. 216 */ 217 sc->nmodes = OF_getproplen(cpu, "power-mode-data"); 218 if (sc->nmodes <= 0 || sc->nmodes > sizeof(sc->pcr_vals)) { 219 device_printf(dev,"No power mode data in device tree!\n"); 220 return (ENXIO); 221 } 222 OF_getprop(cpu, "power-mode-data", modes, sc->nmodes); 223 sc->nmodes /= sizeof(modes[0]); 224 225 /* Sort the modes */ 226 for (i = 0; i < sc->nmodes; i++) 227 sc->pcr_vals[PCR_TO_FREQ(modes[i])] = modes[i]; 228 229 cpufreq_register(dev); 230 return (0); 231 } 232 233 static int 234 pcr_settings(device_t dev, struct cf_setting *sets, int *count) 235 { 236 struct pcr_softc *sc; 237 238 sc = device_get_softc(dev); 239 if (sets == NULL || count == NULL) 240 return (EINVAL); 241 if (*count < sc->nmodes) 242 return (E2BIG); 243 244 /* Return a list of valid settings for this driver. */ 245 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->nmodes); 246 247 sets[0].freq = 10000; sets[0].dev = dev; 248 sets[1].freq = 5000; sets[1].dev = dev; 249 if (sc->nmodes > 2) { 250 sets[2].freq = 2500; 251 sets[2].dev = dev; 252 } 253 *count = sc->nmodes; 254 255 return (0); 256 } 257 258 static int 259 pcr_set(device_t dev, const struct cf_setting *set) 260 { 261 struct pcr_softc *sc; 262 register_t pcr, msr; 263 uint64_t psr; 264 265 if (set == NULL) 266 return (EINVAL); 267 sc = device_get_softc(dev); 268 269 /* Construct the new PCR */ 270 271 pcr = SCOM_PCR_BIT; 272 273 if (set->freq == 10000) 274 pcr |= sc->pcr_vals[0]; 275 else if (set->freq == 5000) 276 pcr |= sc->pcr_vals[1]; 277 else if (set->freq == 2500) 278 pcr |= sc->pcr_vals[2]; 279 280 msr = mfmsr(); 281 mtmsr(msr & ~PSL_EE); isync(); 282 283 /* 970MP requires PCR and PCRH to be cleared first */ 284 285 write_scom(SCOM_PCR,0); /* Clear PCRH */ 286 write_scom(SCOM_PCR,SCOM_PCR_BIT); /* Clear PCR */ 287 288 /* Set PCR */ 289 290 write_scom(SCOM_PCR, pcr); 291 292 /* Wait for completion */ 293 294 do { 295 DELAY(100); 296 psr = read_scom(SCOM_PSR); 297 } while ((psr & PSR_RECEIVED) && !(psr & PSR_COMPLETED)); 298 299 mtmsr(msr); isync(); 300 301 return (0); 302 } 303 304 static int 305 pcr_get(device_t dev, struct cf_setting *set) 306 { 307 uint64_t psr; 308 309 if (set == NULL) 310 return (EINVAL); 311 312 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 313 314 psr = read_scom(SCOM_PSR); 315 316 /* We want bits 6 and 7 */ 317 psr = (psr >> 56) & 3; 318 319 set->freq = 10000; 320 if (psr == PCR_HALF) 321 set->freq = 5000; 322 else if (psr == PCR_QUARTER) 323 set->freq = 2500; 324 325 set->dev = dev; 326 327 return (0); 328 } 329 330 static int 331 pcr_type(device_t dev, int *type) 332 { 333 334 if (type == NULL) 335 return (EINVAL); 336 337 *type = CPUFREQ_TYPE_RELATIVE; 338 return (0); 339 } 340