xref: /freebsd/sys/dev/cpufreq/cpufreq_dt.c (revision 9768746ba83efa02837c5b9c66348db6e900208f)
1 /*-
2  * Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.Org>
3  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * Generic DT based cpufreq driver
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/rman.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/cpu.h>
43 #include <sys/cpuset.h>
44 #include <sys/smp.h>
45 
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include <dev/extres/clk/clk.h>
50 #include <dev/extres/regulator/regulator.h>
51 
52 #include "cpufreq_if.h"
53 
54 #if 0
55 #define DPRINTF(dev, msg...) device_printf(dev, "cpufreq_dt: " msg);
56 #else
57 #define DPRINTF(dev, msg...)
58 #endif
59 
60 enum opp_version {
61 	OPP_V1 = 1,
62 	OPP_V2,
63 };
64 
65 struct cpufreq_dt_opp {
66 	uint64_t	freq;
67 	uint32_t	uvolt_target;
68 	uint32_t	uvolt_min;
69 	uint32_t	uvolt_max;
70 	uint32_t	uamps;
71 	uint32_t	clk_latency;
72 	bool		turbo_mode;
73 	bool		opp_suspend;
74 };
75 
76 #define	CPUFREQ_DT_HAVE_REGULATOR(sc)	((sc)->reg != NULL)
77 
78 struct cpufreq_dt_softc {
79 	device_t dev;
80 	clk_t clk;
81 	regulator_t reg;
82 
83 	struct cpufreq_dt_opp *opp;
84 	ssize_t nopp;
85 
86 	int cpu;
87 	cpuset_t cpus;
88 };
89 
90 static void
91 cpufreq_dt_notify(device_t dev, uint64_t freq)
92 {
93 	struct cpufreq_dt_softc *sc;
94 	struct pcpu *pc;
95 	int cpu;
96 
97 	sc = device_get_softc(dev);
98 
99 	CPU_FOREACH(cpu) {
100 		if (CPU_ISSET(cpu, &sc->cpus)) {
101 			pc = pcpu_find(cpu);
102 			pc->pc_clock = freq;
103 		}
104 	}
105 }
106 
107 static const struct cpufreq_dt_opp *
108 cpufreq_dt_find_opp(device_t dev, uint64_t freq)
109 {
110 	struct cpufreq_dt_softc *sc;
111 	ssize_t n;
112 
113 	sc = device_get_softc(dev);
114 
115 	DPRINTF(dev, "Looking for freq %ju\n", freq);
116 	for (n = 0; n < sc->nopp; n++)
117 		if (CPUFREQ_CMP(sc->opp[n].freq, freq))
118 			return (&sc->opp[n]);
119 
120 	DPRINTF(dev, "Couldn't find one\n");
121 	return (NULL);
122 }
123 
124 static void
125 cpufreq_dt_opp_to_setting(device_t dev, const struct cpufreq_dt_opp *opp,
126     struct cf_setting *set)
127 {
128 
129 	memset(set, 0, sizeof(*set));
130 	set->freq = opp->freq / 1000000;
131 	set->volts = opp->uvolt_target / 1000;
132 	set->power = CPUFREQ_VAL_UNKNOWN;
133 	set->lat = opp->clk_latency;
134 	set->dev = dev;
135 }
136 
137 static int
138 cpufreq_dt_get(device_t dev, struct cf_setting *set)
139 {
140 	struct cpufreq_dt_softc *sc;
141 	const struct cpufreq_dt_opp *opp;
142 	uint64_t freq;
143 
144 	sc = device_get_softc(dev);
145 
146 	DPRINTF(dev, "cpufreq_dt_get\n");
147 	if (clk_get_freq(sc->clk, &freq) != 0)
148 		return (ENXIO);
149 
150 	opp = cpufreq_dt_find_opp(dev, freq);
151 	if (opp == NULL) {
152 		device_printf(dev, "Can't find the current freq in opp\n");
153 		return (ENOENT);
154 	}
155 
156 	cpufreq_dt_opp_to_setting(dev, opp, set);
157 
158 	DPRINTF(dev, "Current freq %dMhz\n", set->freq);
159 	return (0);
160 }
161 
162 static int
163 cpufreq_dt_set(device_t dev, const struct cf_setting *set)
164 {
165 	struct cpufreq_dt_softc *sc;
166 	const struct cpufreq_dt_opp *opp, *copp;
167 	uint64_t freq;
168 	int uvolt, error;
169 
170 	sc = device_get_softc(dev);
171 
172 	DPRINTF(dev, "Working on cpu %d\n", sc->cpu);
173 	DPRINTF(dev, "We have %d cpu on this dev\n", CPU_COUNT(&sc->cpus));
174 	if (!CPU_ISSET(sc->cpu, &sc->cpus)) {
175 		DPRINTF(dev, "Not for this CPU\n");
176 		return (0);
177 	}
178 
179 	if (clk_get_freq(sc->clk, &freq) != 0) {
180 		device_printf(dev, "Can't get current clk freq\n");
181 		return (ENXIO);
182 	}
183 
184 	/*
185 	 * Only do the regulator work if it's required.
186 	 */
187 	if (CPUFREQ_DT_HAVE_REGULATOR(sc)) {
188 		/* Try to get current valtage by using regulator first. */
189 		error = regulator_get_voltage(sc->reg, &uvolt);
190 		if (error != 0) {
191 			/*
192 			 * Try oppoints table as backup way. However,
193 			 * this is insufficient because the actual processor
194 			 * frequency may not be in the table. PLL frequency
195 			 * granularity can be different that granularity of
196 			 * oppoint table.
197 			 */
198 			copp = cpufreq_dt_find_opp(sc->dev, freq);
199 			if (copp == NULL) {
200 				device_printf(dev,
201 				    "Can't find the current freq in opp\n");
202 				return (ENOENT);
203 			}
204 			uvolt = copp->uvolt_target;
205 		}
206 	} else
207 		uvolt = 0;
208 
209 	opp = cpufreq_dt_find_opp(sc->dev, set->freq * 1000000);
210 	if (opp == NULL) {
211 		device_printf(dev, "Couldn't find an opp for this freq\n");
212 		return (EINVAL);
213 	}
214 	DPRINTF(sc->dev, "Current freq %ju, uvolt: %d\n", freq, uvolt);
215 	DPRINTF(sc->dev, "Target freq %ju, , uvolt: %d\n",
216 	    opp->freq, opp->uvolt_target);
217 
218 	if (CPUFREQ_DT_HAVE_REGULATOR(sc) && (uvolt < opp->uvolt_target)) {
219 		DPRINTF(dev, "Changing regulator from %u to %u\n",
220 		    uvolt, opp->uvolt_target);
221 		error = regulator_set_voltage(sc->reg,
222 		    opp->uvolt_min,
223 		    opp->uvolt_max);
224 		if (error != 0) {
225 			DPRINTF(dev, "Failed, backout\n");
226 			return (ENXIO);
227 		}
228 	}
229 
230 	DPRINTF(dev, "Setting clk to %ju\n", opp->freq);
231 	error = clk_set_freq(sc->clk, opp->freq, CLK_SET_ROUND_DOWN);
232 	if (error != 0) {
233 		DPRINTF(dev, "Failed, backout\n");
234 		/* Restore previous voltage (best effort) */
235 		if (CPUFREQ_DT_HAVE_REGULATOR(sc))
236 			error = regulator_set_voltage(sc->reg,
237 			    copp->uvolt_min,
238 			    copp->uvolt_max);
239 		return (ENXIO);
240 	}
241 
242 	if (CPUFREQ_DT_HAVE_REGULATOR(sc) && (uvolt > opp->uvolt_target)) {
243 		DPRINTF(dev, "Changing regulator from %u to %u\n",
244 		    uvolt, opp->uvolt_target);
245 		error = regulator_set_voltage(sc->reg,
246 		    opp->uvolt_min,
247 		    opp->uvolt_max);
248 		if (error != 0) {
249 			DPRINTF(dev, "Failed to switch regulator to %d\n",
250 			    opp->uvolt_target);
251 			/* Restore previous CPU frequency (best effort) */
252 			(void)clk_set_freq(sc->clk, copp->freq, 0);
253 			return (ENXIO);
254 		}
255 	}
256 
257 	if (clk_get_freq(sc->clk, &freq) == 0)
258 		cpufreq_dt_notify(dev, freq);
259 
260 	return (0);
261 }
262 
263 static int
264 cpufreq_dt_type(device_t dev, int *type)
265 {
266 	if (type == NULL)
267 		return (EINVAL);
268 
269 	*type = CPUFREQ_TYPE_ABSOLUTE;
270 	return (0);
271 }
272 
273 static int
274 cpufreq_dt_settings(device_t dev, struct cf_setting *sets, int *count)
275 {
276 	struct cpufreq_dt_softc *sc;
277 	ssize_t n;
278 
279 	DPRINTF(dev, "cpufreq_dt_settings\n");
280 	if (sets == NULL || count == NULL)
281 		return (EINVAL);
282 
283 	sc = device_get_softc(dev);
284 
285 	if (*count < sc->nopp) {
286 		*count = (int)sc->nopp;
287 		return (E2BIG);
288 	}
289 
290 	for (n = 0; n < sc->nopp; n++)
291 		cpufreq_dt_opp_to_setting(dev, &sc->opp[n], &sets[n]);
292 
293 	*count = (int)sc->nopp;
294 
295 	return (0);
296 }
297 
298 static void
299 cpufreq_dt_identify(driver_t *driver, device_t parent)
300 {
301 	phandle_t node;
302 
303 	/* Properties must be listed under node /cpus/cpu@0 */
304 	node = ofw_bus_get_node(parent);
305 
306 	/* The cpu@0 node must have the following properties */
307 	if (!OF_hasprop(node, "clocks"))
308 		return;
309 
310 	if (!OF_hasprop(node, "operating-points") &&
311 	    !OF_hasprop(node, "operating-points-v2"))
312 		return;
313 
314 	if (device_find_child(parent, "cpufreq_dt", -1) != NULL)
315 		return;
316 
317 	if (BUS_ADD_CHILD(parent, 0, "cpufreq_dt", device_get_unit(parent))
318 	    == NULL)
319 		device_printf(parent, "add cpufreq_dt child failed\n");
320 }
321 
322 static int
323 cpufreq_dt_probe(device_t dev)
324 {
325 	phandle_t node;
326 
327 	node = ofw_bus_get_node(device_get_parent(dev));
328 
329 	/*
330 	 * Note - supply isn't required here for probe; we'll check
331 	 * it out in more detail during attach.
332 	 */
333 	if (!OF_hasprop(node, "clocks"))
334 		return (ENXIO);
335 
336 	if (!OF_hasprop(node, "operating-points") &&
337 	  !OF_hasprop(node, "operating-points-v2"))
338 		return (ENXIO);
339 
340 	device_set_desc(dev, "Generic cpufreq driver");
341 	return (BUS_PROBE_GENERIC);
342 }
343 
344 static int
345 cpufreq_dt_oppv1_parse(struct cpufreq_dt_softc *sc, phandle_t node)
346 {
347 	uint32_t *opp, lat;
348 	ssize_t n;
349 
350 	sc->nopp = OF_getencprop_alloc_multi(node, "operating-points",
351 	    sizeof(uint32_t) * 2, (void **)&opp);
352 	if (sc->nopp == -1)
353 		return (ENXIO);
354 
355 	if (OF_getencprop(node, "clock-latency", &lat, sizeof(lat)) == -1)
356 		lat = CPUFREQ_VAL_UNKNOWN;
357 
358 	sc->opp = malloc(sizeof(*sc->opp) * sc->nopp, M_DEVBUF, M_WAITOK);
359 
360 	for (n = 0; n < sc->nopp; n++) {
361 		sc->opp[n].freq = opp[n * 2 + 0] * 1000;
362 		sc->opp[n].uvolt_min = opp[n * 2 + 1];
363 		sc->opp[n].uvolt_max = sc->opp[n].uvolt_min;
364 		sc->opp[n].uvolt_target = sc->opp[n].uvolt_min;
365 		sc->opp[n].clk_latency = lat;
366 
367 		if (bootverbose)
368 			device_printf(sc->dev, "%ju.%03ju MHz, %u uV\n",
369 			    sc->opp[n].freq / 1000000,
370 			    sc->opp[n].freq % 1000000,
371 			    sc->opp[n].uvolt_target);
372 	}
373 	free(opp, M_OFWPROP);
374 
375 	return (0);
376 }
377 
378 static int
379 cpufreq_dt_oppv2_parse(struct cpufreq_dt_softc *sc, phandle_t node)
380 {
381 	phandle_t opp, opp_table, opp_xref;
382 	pcell_t cell[2];
383 	uint32_t *volts, lat;
384 	int nvolt, i;
385 
386 	/*
387 	 * operating-points-v2 does not require the voltage entries
388 	 * and a regulator.  So, it's OK if they're not there.
389 	 */
390 	if (OF_getencprop(node, "operating-points-v2", &opp_xref,
391 	    sizeof(opp_xref)) == -1) {
392 		device_printf(sc->dev, "Cannot get xref to oppv2 table\n");
393 		return (ENXIO);
394 	}
395 
396 	opp_table = OF_node_from_xref(opp_xref);
397 	if (opp_table == opp_xref)
398 		return (ENXIO);
399 
400 	if (!OF_hasprop(opp_table, "opp-shared")) {
401 		device_printf(sc->dev, "Only opp-shared is supported\n");
402 		return (ENXIO);
403 	}
404 
405 	for (opp = OF_child(opp_table); opp > 0; opp = OF_peer(opp))
406 		sc->nopp += 1;
407 
408 	sc->opp = malloc(sizeof(*sc->opp) * sc->nopp, M_DEVBUF, M_WAITOK);
409 
410 	for (i = 0, opp_table = OF_child(opp_table); opp_table > 0;
411 	     opp_table = OF_peer(opp_table), i++) {
412 		/* opp-hz is a required property */
413 		if (OF_getencprop(opp_table, "opp-hz", cell,
414 		    sizeof(cell)) == -1)
415 			continue;
416 
417 		sc->opp[i].freq = cell[0];
418 		sc->opp[i].freq <<= 32;
419 		sc->opp[i].freq |= cell[1];
420 
421 		if (OF_getencprop(opp_table, "clock-latency", &lat,
422 		    sizeof(lat)) == -1)
423 			sc->opp[i].clk_latency = CPUFREQ_VAL_UNKNOWN;
424 		else
425 			sc->opp[i].clk_latency = (int)lat;
426 
427 		if (OF_hasprop(opp_table, "turbo-mode"))
428 			sc->opp[i].turbo_mode = true;
429 		if (OF_hasprop(opp_table, "opp-suspend"))
430 			sc->opp[i].opp_suspend = true;
431 
432 		if (CPUFREQ_DT_HAVE_REGULATOR(sc)) {
433 			nvolt = OF_getencprop_alloc_multi(opp_table,
434 			    "opp-microvolt", sizeof(*volts), (void **)&volts);
435 			if (nvolt == 1) {
436 				sc->opp[i].uvolt_target = volts[0];
437 				sc->opp[i].uvolt_min = volts[0];
438 				sc->opp[i].uvolt_max = volts[0];
439 			} else if (nvolt == 3) {
440 				sc->opp[i].uvolt_target = volts[0];
441 				sc->opp[i].uvolt_min = volts[1];
442 				sc->opp[i].uvolt_max = volts[2];
443 			} else {
444 				device_printf(sc->dev,
445 				    "Wrong count of opp-microvolt property\n");
446 				OF_prop_free(volts);
447 				free(sc->opp, M_DEVBUF);
448 				return (ENXIO);
449 			}
450 			OF_prop_free(volts);
451 		} else {
452 			/* No regulator required; don't add anything */
453 			sc->opp[i].uvolt_target = 0;
454 			sc->opp[i].uvolt_min = 0;
455 			sc->opp[i].uvolt_max = 0;
456 		}
457 
458 		if (bootverbose)
459 			device_printf(sc->dev, "%ju.%03ju Mhz (%u uV)\n",
460 			    sc->opp[i].freq / 1000000,
461 			    sc->opp[i].freq % 1000000,
462 			    sc->opp[i].uvolt_target);
463 	}
464 	return (0);
465 }
466 
467 static int
468 cpufreq_dt_attach(device_t dev)
469 {
470 	struct cpufreq_dt_softc *sc;
471 	phandle_t node;
472 	phandle_t cnode, opp, copp;
473 	int cpu;
474 	uint64_t freq;
475 	int rv = 0;
476 	char device_type[16];
477 	enum opp_version version;
478 
479 	sc = device_get_softc(dev);
480 	sc->dev = dev;
481 	node = ofw_bus_get_node(device_get_parent(dev));
482 	sc->cpu = device_get_unit(device_get_parent(dev));
483 	sc->reg = NULL;
484 
485 	DPRINTF(dev, "cpu=%d\n", sc->cpu);
486 	if (sc->cpu >= mp_ncpus) {
487 		device_printf(dev, "Not attaching as cpu is not present\n");
488 		rv = ENXIO;
489 		goto error;
490 	}
491 
492 	/*
493 	 * Cache if we have the regulator supply but don't error out
494 	 * quite yet.  If it's operating-points-v2 then regulator
495 	 * and voltage entries are optional.
496 	 */
497 	if (regulator_get_by_ofw_property(dev, node, "cpu-supply",
498 	    &sc->reg) == 0)
499 		device_printf(dev, "Found cpu-supply\n");
500 	else if (regulator_get_by_ofw_property(dev, node, "cpu0-supply",
501 	    &sc->reg) == 0)
502 		device_printf(dev, "Found cpu0-supply\n");
503 
504 	/*
505 	 * Determine which operating mode we're in.  Error out if we expect
506 	 * a regulator but we're not getting it.
507 	 */
508 	if (OF_hasprop(node, "operating-points"))
509 		version = OPP_V1;
510 	else if (OF_hasprop(node, "operating-points-v2"))
511 		version = OPP_V2;
512 	else {
513 		device_printf(dev,
514 		    "didn't find a valid operating-points or v2 node\n");
515 		rv = ENXIO;
516 		goto error;
517 	}
518 
519 	/*
520 	 * Now, we only enforce needing a regulator for v1.
521 	 */
522 	if ((version == OPP_V1) && !CPUFREQ_DT_HAVE_REGULATOR(sc)) {
523 		device_printf(dev, "no regulator for %s\n",
524 		    ofw_bus_get_name(device_get_parent(dev)));
525 		rv = ENXIO;
526 		goto error;
527 	}
528 
529 	if (clk_get_by_ofw_index(dev, node, 0, &sc->clk) != 0) {
530 		device_printf(dev, "no clock for %s\n",
531 		    ofw_bus_get_name(device_get_parent(dev)));
532 		rv = ENXIO;
533 		goto error;
534 	}
535 
536 	if (version == OPP_V1) {
537 		rv = cpufreq_dt_oppv1_parse(sc, node);
538 		if (rv != 0) {
539 			device_printf(dev, "Failed to parse opp-v1 table\n");
540 			goto error;
541 		}
542 		OF_getencprop(node, "operating-points", &opp,
543 		    sizeof(opp));
544 	} else if (version == OPP_V2) {
545 		rv = cpufreq_dt_oppv2_parse(sc, node);
546 		if (rv != 0) {
547 			device_printf(dev, "Failed to parse opp-v2 table\n");
548 			goto error;
549 		}
550 		OF_getencprop(node, "operating-points-v2", &opp,
551 		    sizeof(opp));
552 	} else {
553 		device_printf(dev, "operating points version is incorrect\n");
554 		goto error;
555 	}
556 
557 	/*
558 	 * Find all CPUs that share the same opp table
559 	 */
560 	CPU_ZERO(&sc->cpus);
561 	cnode = OF_parent(node);
562 	for (cpu = 0, cnode = OF_child(cnode); cnode > 0; cnode = OF_peer(cnode)) {
563 		if (OF_getprop(cnode, "device_type", device_type, sizeof(device_type)) <= 0)
564 			continue;
565 		if (strcmp(device_type, "cpu") != 0)
566 			continue;
567 		if (cpu == sc->cpu) {
568 			DPRINTF(dev, "Skipping our cpu\n");
569 			CPU_SET(cpu, &sc->cpus);
570 			cpu++;
571 			continue;
572 		}
573 		DPRINTF(dev, "Testing CPU %d\n", cpu);
574 		copp = -1;
575 		if (version == OPP_V1)
576 			OF_getencprop(cnode, "operating-points", &copp,
577 			    sizeof(copp));
578 		else if (version == OPP_V2)
579 			OF_getencprop(cnode, "operating-points-v2",
580 			    &copp, sizeof(copp));
581 		if (opp == copp) {
582 			DPRINTF(dev, "CPU %d is using the same opp as this one (%d)\n",
583 			    cpu, sc->cpu);
584 			CPU_SET(cpu, &sc->cpus);
585 		}
586 		cpu++;
587 	}
588 
589 	if (clk_get_freq(sc->clk, &freq) == 0)
590 		cpufreq_dt_notify(dev, freq);
591 
592 	cpufreq_register(dev);
593 
594 	return (0);
595 error:
596 	if (CPUFREQ_DT_HAVE_REGULATOR(sc))
597 		regulator_release(sc->reg);
598 	return (rv);
599 }
600 
601 static device_method_t cpufreq_dt_methods[] = {
602 	/* Device interface */
603 	DEVMETHOD(device_identify,	cpufreq_dt_identify),
604 	DEVMETHOD(device_probe,		cpufreq_dt_probe),
605 	DEVMETHOD(device_attach,	cpufreq_dt_attach),
606 
607 	/* cpufreq interface */
608 	DEVMETHOD(cpufreq_drv_get,	cpufreq_dt_get),
609 	DEVMETHOD(cpufreq_drv_set,	cpufreq_dt_set),
610 	DEVMETHOD(cpufreq_drv_type,	cpufreq_dt_type),
611 	DEVMETHOD(cpufreq_drv_settings,	cpufreq_dt_settings),
612 
613 	DEVMETHOD_END
614 };
615 
616 static driver_t cpufreq_dt_driver = {
617 	"cpufreq_dt",
618 	cpufreq_dt_methods,
619 	sizeof(struct cpufreq_dt_softc),
620 };
621 
622 DRIVER_MODULE(cpufreq_dt, cpu, cpufreq_dt_driver, 0, 0);
623 MODULE_VERSION(cpufreq_dt, 1);
624