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/cdefs.h> 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/bus.h> 33 #include <sys/cpu.h> 34 #include <sys/kernel.h> 35 #include <sys/module.h> 36 37 #include <dev/ofw/ofw_bus.h> 38 39 #include "cpufreq_if.h" 40 41 struct pcr_softc { 42 device_t dev; 43 uint32_t pcr_vals[3]; 44 int nmodes; 45 }; 46 47 static void pcr_identify(driver_t *driver, device_t parent); 48 static int pcr_probe(device_t dev); 49 static int pcr_attach(device_t dev); 50 static int pcr_settings(device_t dev, struct cf_setting *sets, int *count); 51 static int pcr_set(device_t dev, const struct cf_setting *set); 52 static int pcr_get(device_t dev, struct cf_setting *set); 53 static int pcr_type(device_t dev, int *type); 54 55 static device_method_t pcr_methods[] = { 56 /* Device interface */ 57 DEVMETHOD(device_identify, pcr_identify), 58 DEVMETHOD(device_probe, pcr_probe), 59 DEVMETHOD(device_attach, pcr_attach), 60 61 /* cpufreq interface */ 62 DEVMETHOD(cpufreq_drv_set, pcr_set), 63 DEVMETHOD(cpufreq_drv_get, pcr_get), 64 DEVMETHOD(cpufreq_drv_type, pcr_type), 65 DEVMETHOD(cpufreq_drv_settings, pcr_settings), 66 {0, 0} 67 }; 68 69 static driver_t pcr_driver = { 70 "pcr", 71 pcr_methods, 72 sizeof(struct pcr_softc) 73 }; 74 75 DRIVER_MODULE(pcr, cpu, pcr_driver, 0, 0); 76 77 /* 78 * States 79 */ 80 81 #define PCR_TO_FREQ(a) ((a >> 17) & 3) 82 83 #define PCR_FULL 0 84 #define PCR_HALF 1 85 #define PCR_QUARTER 2 /* Only on 970MP */ 86 87 #define PSR_RECEIVED (1ULL << 61) 88 #define PSR_COMPLETED (1ULL << 61) 89 90 /* 91 * SCOM addresses 92 */ 93 94 #define SCOM_PCR 0x0aa00100 /* Power Control Register */ 95 #define SCOM_PCR_BIT 0x80000000 /* Data bit for PCR */ 96 #define SCOM_PSR 0x40800100 /* Power Status Register */ 97 98 /* 99 * SCOM Glue 100 */ 101 102 #define SCOMC_READ 0x00008000 103 #define SCOMC_WRITE 0x00000000 104 105 static void 106 write_scom(register_t address, uint64_t value) 107 { 108 register_t msr; 109 #ifndef __powerpc64__ 110 register_t hi, lo, scratch; 111 #endif 112 113 msr = mfmsr(); 114 mtmsr(msr & ~PSL_EE); isync(); 115 116 #ifdef __powerpc64__ 117 mtspr(SPR_SCOMD, value); 118 #else 119 hi = (value >> 32) & 0xffffffff; 120 lo = value & 0xffffffff; 121 mtspr64(SPR_SCOMD, hi, lo, scratch); 122 #endif 123 isync(); 124 mtspr(SPR_SCOMC, address | SCOMC_WRITE); 125 isync(); 126 127 mtmsr(msr); isync(); 128 } 129 130 static uint64_t 131 read_scom(register_t address) 132 { 133 register_t msr; 134 uint64_t ret; 135 136 msr = mfmsr(); 137 mtmsr(msr & ~PSL_EE); isync(); 138 139 mtspr(SPR_SCOMC, address | SCOMC_READ); 140 isync(); 141 142 __asm __volatile ("mfspr %0,%1;" 143 " mr %0+1, %0; srdi %0,%0,32" : "=r" (ret) : "K" (SPR_SCOMD)); 144 145 (void)mfspr(SPR_SCOMC); /* Complete transcation */ 146 147 mtmsr(msr); isync(); 148 149 return (ret); 150 } 151 152 static void 153 pcr_identify(driver_t *driver, device_t parent) 154 { 155 uint16_t vers; 156 vers = mfpvr() >> 16; 157 158 /* Check for an IBM 970-class CPU */ 159 switch (vers) { 160 case IBM970FX: 161 case IBM970GX: 162 case IBM970MP: 163 break; 164 default: 165 return; 166 } 167 168 /* Make sure we're not being doubly invoked. */ 169 if (device_find_child(parent, "pcr", -1) != NULL) 170 return; 171 172 /* 173 * We attach a child for every CPU since settings need to 174 * be performed on every CPU in the SMP case. 175 */ 176 if (BUS_ADD_CHILD(parent, 10, "pcr", -1) == NULL) 177 device_printf(parent, "add pcr child failed\n"); 178 } 179 180 static int 181 pcr_probe(device_t dev) 182 { 183 if (resource_disabled("pcr", 0)) 184 return (ENXIO); 185 186 device_set_desc(dev, "PPC 970 Power Control Register"); 187 return (0); 188 } 189 190 static int 191 pcr_attach(device_t dev) 192 { 193 struct pcr_softc *sc; 194 phandle_t cpu; 195 uint32_t modes[3]; 196 int i; 197 198 sc = device_get_softc(dev); 199 sc->dev = dev; 200 201 cpu = ofw_bus_get_node(device_get_parent(dev)); 202 203 if (cpu <= 0) { 204 device_printf(dev,"No CPU device tree node!\n"); 205 return (ENXIO); 206 } 207 208 if (OF_getproplen(cpu, "power-mode-data") <= 0) { 209 /* Use the first CPU's node */ 210 cpu = OF_child(OF_parent(cpu)); 211 } 212 213 /* 214 * Collect the PCR values for each mode from the device tree. 215 * These include bus timing information, and so cannot be 216 * directly computed. 217 */ 218 sc->nmodes = OF_getproplen(cpu, "power-mode-data"); 219 if (sc->nmodes <= 0 || sc->nmodes > sizeof(sc->pcr_vals)) { 220 device_printf(dev,"No power mode data in device tree!\n"); 221 return (ENXIO); 222 } 223 OF_getprop(cpu, "power-mode-data", modes, sc->nmodes); 224 sc->nmodes /= sizeof(modes[0]); 225 226 /* Sort the modes */ 227 for (i = 0; i < sc->nmodes; i++) 228 sc->pcr_vals[PCR_TO_FREQ(modes[i])] = modes[i]; 229 230 cpufreq_register(dev); 231 return (0); 232 } 233 234 static int 235 pcr_settings(device_t dev, struct cf_setting *sets, int *count) 236 { 237 struct pcr_softc *sc; 238 239 sc = device_get_softc(dev); 240 if (sets == NULL || count == NULL) 241 return (EINVAL); 242 if (*count < sc->nmodes) 243 return (E2BIG); 244 245 /* Return a list of valid settings for this driver. */ 246 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->nmodes); 247 248 sets[0].freq = 10000; sets[0].dev = dev; 249 sets[1].freq = 5000; sets[1].dev = dev; 250 if (sc->nmodes > 2) { 251 sets[2].freq = 2500; 252 sets[2].dev = dev; 253 } 254 *count = sc->nmodes; 255 256 return (0); 257 } 258 259 static int 260 pcr_set(device_t dev, const struct cf_setting *set) 261 { 262 struct pcr_softc *sc; 263 register_t pcr, msr; 264 uint64_t psr; 265 266 if (set == NULL) 267 return (EINVAL); 268 sc = device_get_softc(dev); 269 270 /* Construct the new PCR */ 271 272 pcr = SCOM_PCR_BIT; 273 274 if (set->freq == 10000) 275 pcr |= sc->pcr_vals[0]; 276 else if (set->freq == 5000) 277 pcr |= sc->pcr_vals[1]; 278 else if (set->freq == 2500) 279 pcr |= sc->pcr_vals[2]; 280 281 msr = mfmsr(); 282 mtmsr(msr & ~PSL_EE); isync(); 283 284 /* 970MP requires PCR and PCRH to be cleared first */ 285 286 write_scom(SCOM_PCR,0); /* Clear PCRH */ 287 write_scom(SCOM_PCR,SCOM_PCR_BIT); /* Clear PCR */ 288 289 /* Set PCR */ 290 291 write_scom(SCOM_PCR, pcr); 292 293 /* Wait for completion */ 294 295 do { 296 DELAY(100); 297 psr = read_scom(SCOM_PSR); 298 } while ((psr & PSR_RECEIVED) && !(psr & PSR_COMPLETED)); 299 300 mtmsr(msr); isync(); 301 302 return (0); 303 } 304 305 static int 306 pcr_get(device_t dev, struct cf_setting *set) 307 { 308 uint64_t psr; 309 310 if (set == NULL) 311 return (EINVAL); 312 313 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 314 315 psr = read_scom(SCOM_PSR); 316 317 /* We want bits 6 and 7 */ 318 psr = (psr >> 56) & 3; 319 320 set->freq = 10000; 321 if (psr == PCR_HALF) 322 set->freq = 5000; 323 else if (psr == PCR_QUARTER) 324 set->freq = 2500; 325 326 set->dev = dev; 327 328 return (0); 329 } 330 331 static int 332 pcr_type(device_t dev, int *type) 333 { 334 335 if (type == NULL) 336 return (EINVAL); 337 338 *type = CPUFREQ_TYPE_RELATIVE; 339 return (0); 340 } 341