cpufreq_dt.c revision 1.2
1 /* $NetBSD: cpufreq_dt.c,v 1.2 2017/10/05 01:28:01 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2015-2017 Jared McNeill <jmcneill (at) invisible.ca> 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 __KERNEL_RCSID(0, "$NetBSD: cpufreq_dt.c,v 1.2 2017/10/05 01:28:01 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/device.h> 35 #include <sys/kmem.h> 36 #include <sys/bus.h> 37 #include <sys/atomic.h> 38 #include <sys/xcall.h> 39 #include <sys/sysctl.h> 40 41 #include <dev/fdt/fdtvar.h> 42 43 struct cpufreq_dt_opp { 44 u_int freq_khz; 45 u_int voltage_uv; 46 }; 47 48 struct cpufreq_dt_softc { 49 device_t sc_dev; 50 int sc_phandle; 51 struct clk *sc_clk; 52 struct fdtbus_regulator *sc_supply; 53 54 struct cpufreq_dt_opp *sc_opp; 55 ssize_t sc_nopp; 56 int sc_latency; 57 58 u_int sc_freq_target; 59 bool sc_freq_throttle; 60 61 u_int sc_busy; 62 63 char *sc_freq_available; 64 int sc_node_target; 65 int sc_node_current; 66 int sc_node_available; 67 }; 68 69 static void 70 cpufreq_dt_change_cb(void *arg1, void *arg2) 71 { 72 #if notyet 73 struct cpu_info *ci = curcpu(); 74 ci->ci_data.cpu_cc_freq = cpufreq_get_rate() * 1000000; 75 #endif 76 } 77 78 static int 79 cpufreq_dt_set_rate(struct cpufreq_dt_softc *sc, u_int freq_khz) 80 { 81 struct cpufreq_dt_opp *opp = NULL; 82 u_int old_rate, new_rate, old_uv, new_uv; 83 uint64_t xc; 84 int error; 85 ssize_t n; 86 87 for (n = 0; n < sc->sc_nopp; n++) 88 if (sc->sc_opp[n].freq_khz == freq_khz) { 89 opp = &sc->sc_opp[n]; 90 break; 91 } 92 if (opp == NULL) 93 return EINVAL; 94 95 old_rate = clk_get_rate(sc->sc_clk); 96 new_rate = freq_khz * 1000; 97 98 if (old_rate == new_rate) 99 return 0; 100 101 error = fdtbus_regulator_get_voltage(sc->sc_supply, &old_uv); 102 if (error != 0) 103 return error; 104 new_uv = opp->voltage_uv; 105 106 if (new_uv > old_uv) { 107 error = fdtbus_regulator_set_voltage(sc->sc_supply, 108 new_uv, new_uv); 109 if (error != 0) 110 return error; 111 } 112 113 error = clk_set_rate(sc->sc_clk, new_rate); 114 if (error != 0) 115 return error; 116 117 if (new_uv < old_uv) { 118 error = fdtbus_regulator_set_voltage(sc->sc_supply, 119 new_uv, new_uv); 120 if (error != 0) 121 return error; 122 } 123 124 if (error == 0) { 125 xc = xc_broadcast(0, cpufreq_dt_change_cb, sc, NULL); 126 xc_wait(xc); 127 128 pmf_event_inject(NULL, PMFE_SPEED_CHANGED); 129 } 130 131 return 0; 132 } 133 134 static void 135 cpufreq_dt_throttle_enable(device_t dev) 136 { 137 struct cpufreq_dt_softc * const sc = device_private(dev); 138 139 if (sc->sc_freq_throttle) 140 return; 141 142 const u_int freq_khz = sc->sc_opp[sc->sc_nopp - 1].freq_khz; 143 144 while (atomic_cas_uint(&sc->sc_busy, 0, 1) != 0) 145 kpause("throttle", false, 1, NULL); 146 147 if (cpufreq_dt_set_rate(sc, freq_khz) == 0) { 148 aprint_debug_dev(sc->sc_dev, "throttle enabled (%u.%03u MHz)\n", 149 freq_khz / 1000, freq_khz % 1000); 150 sc->sc_freq_throttle = true; 151 if (sc->sc_freq_target == 0) 152 sc->sc_freq_target = clk_get_rate(sc->sc_clk) / 1000000; 153 } 154 155 atomic_dec_uint(&sc->sc_busy); 156 } 157 158 static void 159 cpufreq_dt_throttle_disable(device_t dev) 160 { 161 struct cpufreq_dt_softc * const sc = device_private(dev); 162 163 if (!sc->sc_freq_throttle) 164 return; 165 166 while (atomic_cas_uint(&sc->sc_busy, 0, 1) != 0) 167 kpause("throttle", false, 1, NULL); 168 169 const u_int freq_khz = sc->sc_freq_target * 1000; 170 171 if (cpufreq_dt_set_rate(sc, freq_khz) == 0) { 172 aprint_debug_dev(sc->sc_dev, "throttle disabled (%u.%03u MHz)\n", 173 freq_khz / 1000, freq_khz % 1000); 174 sc->sc_freq_throttle = false; 175 } 176 177 atomic_dec_uint(&sc->sc_busy); 178 } 179 180 static int 181 cpufreq_dt_sysctl_helper(SYSCTLFN_ARGS) 182 { 183 struct cpufreq_dt_softc * const sc = rnode->sysctl_data; 184 struct sysctlnode node; 185 u_int fq, oldfq = 0; 186 int error, n; 187 188 node = *rnode; 189 node.sysctl_data = &fq; 190 191 if (rnode->sysctl_num == sc->sc_node_target) { 192 if (sc->sc_freq_target == 0) 193 sc->sc_freq_target = clk_get_rate(sc->sc_clk) / 1000000; 194 fq = sc->sc_freq_target; 195 } else 196 fq = clk_get_rate(sc->sc_clk) / 1000000; 197 198 if (rnode->sysctl_num == sc->sc_node_target) 199 oldfq = fq; 200 201 if (sc->sc_freq_target == 0) 202 sc->sc_freq_target = fq; 203 204 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 205 if (error || newp == NULL) 206 return error; 207 208 if (fq == oldfq || rnode->sysctl_num != sc->sc_node_target) 209 return 0; 210 211 for (n = 0; n < sc->sc_nopp; n++) 212 if (sc->sc_opp[n].freq_khz / 1000 == fq) 213 break; 214 if (n == sc->sc_nopp) 215 return EINVAL; 216 217 if (atomic_cas_uint(&sc->sc_busy, 0, 1) != 0) 218 return EBUSY; 219 220 sc->sc_freq_target = fq; 221 222 if (sc->sc_freq_throttle) 223 error = 0; 224 else 225 error = cpufreq_dt_set_rate(sc, fq * 1000); 226 227 atomic_dec_uint(&sc->sc_busy); 228 229 return error; 230 } 231 232 static void 233 cpufreq_dt_init_sysctl(struct cpufreq_dt_softc *sc) 234 { 235 const struct sysctlnode *node, *cpunode, *freqnode; 236 struct sysctllog *cpufreq_log = NULL; 237 int error, i; 238 239 sc->sc_freq_available = kmem_zalloc(strlen("XXXX ") * sc->sc_nopp, KM_SLEEP); 240 for (i = 0; i < sc->sc_nopp; i++) { 241 char buf[6]; 242 snprintf(buf, sizeof(buf), i ? " %u" : "%u", sc->sc_opp[i].freq_khz / 1000); 243 strcat(sc->sc_freq_available, buf); 244 } 245 246 error = sysctl_createv(&cpufreq_log, 0, NULL, &node, 247 CTLFLAG_PERMANENT, CTLTYPE_NODE, "machdep", NULL, 248 NULL, 0, NULL, 0, CTL_MACHDEP, CTL_EOL); 249 if (error) 250 goto sysctl_failed; 251 error = sysctl_createv(&cpufreq_log, 0, &node, &cpunode, 252 0, CTLTYPE_NODE, "cpu", NULL, 253 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL); 254 if (error) 255 goto sysctl_failed; 256 error = sysctl_createv(&cpufreq_log, 0, &cpunode, &freqnode, 257 0, CTLTYPE_NODE, "frequency", NULL, 258 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL); 259 if (error) 260 goto sysctl_failed; 261 262 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node, 263 CTLFLAG_READWRITE, CTLTYPE_INT, "target", NULL, 264 cpufreq_dt_sysctl_helper, 0, (void *)sc, 0, 265 CTL_CREATE, CTL_EOL); 266 if (error) 267 goto sysctl_failed; 268 sc->sc_node_target = node->sysctl_num; 269 270 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node, 271 CTLFLAG_READWRITE, CTLTYPE_INT, "current", NULL, 272 cpufreq_dt_sysctl_helper, 0, (void *)sc, 0, 273 CTL_CREATE, CTL_EOL); 274 if (error) 275 goto sysctl_failed; 276 sc->sc_node_current = node->sysctl_num; 277 278 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node, 279 0, CTLTYPE_STRING, "available", NULL, 280 NULL, 0, sc->sc_freq_available, 0, 281 CTL_CREATE, CTL_EOL); 282 if (error) 283 goto sysctl_failed; 284 sc->sc_node_available = node->sysctl_num; 285 286 return; 287 288 sysctl_failed: 289 aprint_error_dev(sc->sc_dev, "couldn't create sysctl nodes: %d\n", error); 290 sysctl_teardown(&cpufreq_log); 291 } 292 293 static int 294 cpufreq_dt_parse(struct cpufreq_dt_softc *sc) 295 { 296 const int phandle = sc->sc_phandle; 297 const u_int *opp; 298 int len, i; 299 u_int lat; 300 301 sc->sc_supply = fdtbus_regulator_acquire(phandle, "cpu-supply"); 302 if (sc->sc_supply == NULL) { 303 aprint_error_dev(sc->sc_dev, "couldn't acquire cpu-supply\n"); 304 return ENXIO; 305 } 306 sc->sc_clk = fdtbus_clock_get_index(phandle, 0); 307 if (sc->sc_clk == NULL) { 308 aprint_error_dev(sc->sc_dev, "couldn't acquire clock\n"); 309 return ENXIO; 310 } 311 312 opp = fdtbus_get_prop(phandle, "operating-points", &len); 313 if (len < 8) 314 return ENXIO; 315 316 sc->sc_nopp = len / 8; 317 sc->sc_opp = kmem_zalloc(sizeof(*sc->sc_opp) * sc->sc_nopp, KM_SLEEP); 318 for (i = 0; i < sc->sc_nopp; i++, opp += 2) { 319 sc->sc_opp[i].freq_khz = be32toh(opp[0]); 320 sc->sc_opp[i].voltage_uv = be32toh(opp[1]); 321 322 aprint_verbose_dev(sc->sc_dev, "%u.%03u MHz, %u uV\n", 323 sc->sc_opp[i].freq_khz / 1000, 324 sc->sc_opp[i].freq_khz % 1000, 325 sc->sc_opp[i].voltage_uv); 326 } 327 328 if (of_getprop_uint32(phandle, "clock-latency", &lat) == 0) 329 sc->sc_latency = lat; 330 else 331 sc->sc_latency = -1; 332 333 return 0; 334 } 335 336 static int 337 cpufreq_dt_match(device_t parent, cfdata_t cf, void *aux) 338 { 339 struct fdt_attach_args * const faa = aux; 340 const int phandle = faa->faa_phandle; 341 bus_addr_t addr; 342 343 if (fdtbus_get_reg(phandle, 0, &addr, NULL) != 0) 344 return 0; 345 /* Generic DT cpufreq driver properties must be defined under /cpus/cpu@0 */ 346 if (addr != 0) 347 return 0; 348 349 if (!of_hasprop(phandle, "operating-points") || 350 !of_hasprop(phandle, "clocks") || 351 !of_hasprop(phandle, "cpu-supply")) 352 return 0; 353 354 return 1; 355 } 356 357 static void 358 cpufreq_dt_init(device_t self) 359 { 360 struct cpufreq_dt_softc * const sc = device_private(self); 361 int error; 362 363 if ((error = cpufreq_dt_parse(sc)) != 0) 364 return; 365 366 cpufreq_dt_init_sysctl(sc); 367 } 368 369 static void 370 cpufreq_dt_attach(device_t parent, device_t self, void *aux) 371 { 372 struct cpufreq_dt_softc * const sc = device_private(self); 373 struct fdt_attach_args * const faa = aux; 374 375 sc->sc_dev = self; 376 sc->sc_phandle = faa->faa_phandle; 377 378 aprint_naive("\n"); 379 aprint_normal("\n"); 380 381 pmf_event_register(self, PMFE_THROTTLE_ENABLE, cpufreq_dt_throttle_enable, true); 382 pmf_event_register(self, PMFE_THROTTLE_DISABLE, cpufreq_dt_throttle_disable, true); 383 384 config_interrupts(self, cpufreq_dt_init); 385 } 386 387 CFATTACH_DECL_NEW(cpufreq_dt, sizeof(struct cpufreq_dt_softc), 388 cpufreq_dt_match, cpufreq_dt_attach, NULL, NULL); 389
Indexes created Thu Sep 25 16:09:42 GMT 2025