xref: /freebsd/sys/arm/freescale/imx/imx6_anatop.c (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
5  * Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 /*
32  * Analog PLL and power regulator driver for Freescale i.MX6 family of SoCs.
33  * Also, temperature montoring and cpu frequency control.  It was Freescale who
34  * kitchen-sinked this device, not us. :)
35  *
36  * We don't really do anything with analog PLLs, but the registers for
37  * controlling them belong to the same block as the power regulator registers.
38  * Since the newbus hierarchy makes it hard for anyone other than us to get at
39  * them, we just export a couple public functions to allow the imx6 CCM clock
40  * driver to read and write those registers.
41  *
42  * We also don't do anything about power regulation yet, but when the need
43  * arises, this would be the place for that code to live.
44  *
45  * I have no idea where the "anatop" name comes from.  It's in the standard DTS
46  * source describing i.MX6 SoCs, and in the linux and u-boot code which comes
47  * from Freescale, but it's not in the SoC manual.
48  *
49  * Note that temperature values throughout this code are handled in two types of
50  * units.  Items with '_cnt' in the name use the hardware temperature count
51  * units (higher counts are lower temperatures).  Items with '_val' in the name
52  * are deci-Celsius, which are converted to/from deci-Kelvins in the sysctl
53  * handlers (dK is the standard unit for temperature in sysctl).
54  */
55 
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/callout.h>
59 #include <sys/kernel.h>
60 #include <sys/limits.h>
61 #include <sys/sysctl.h>
62 #include <sys/module.h>
63 #include <sys/bus.h>
64 #include <sys/rman.h>
65 
66 #include <dev/ofw/ofw_bus.h>
67 #include <dev/ofw/ofw_bus_subr.h>
68 
69 #include <machine/bus.h>
70 
71 #include <arm/arm/mpcore_timervar.h>
72 #include <arm/freescale/fsl_ocotpreg.h>
73 #include <arm/freescale/fsl_ocotpvar.h>
74 #include <arm/freescale/imx/imx_ccmvar.h>
75 #include <arm/freescale/imx/imx_machdep.h>
76 #include <arm/freescale/imx/imx6_anatopreg.h>
77 #include <arm/freescale/imx/imx6_anatopvar.h>
78 
79 static struct resource_spec imx6_anatop_spec[] = {
80 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
81 	{ -1, 0 }
82 };
83 #define	MEMRES	0
84 #define	IRQRES	1
85 
86 struct imx6_anatop_softc {
87 	device_t	dev;
88 	struct resource	*res[2];
89 	struct intr_config_hook
90 			intr_setup_hook;
91 	uint32_t	cpu_curmhz;
92 	uint32_t	cpu_curmv;
93 	uint32_t	cpu_minmhz;
94 	uint32_t	cpu_minmv;
95 	uint32_t	cpu_maxmhz;
96 	uint32_t	cpu_maxmv;
97 	uint32_t	cpu_maxmhz_hw;
98 	boolean_t	cpu_overclock_enable;
99 	boolean_t	cpu_init_done;
100 	uint32_t	refosc_mhz;
101 	void		*temp_intrhand;
102 	uint32_t	temp_high_val;
103 	uint32_t	temp_high_cnt;
104 	uint32_t	temp_last_cnt;
105 	uint32_t	temp_room_cnt;
106 	struct callout	temp_throttle_callout;
107 	sbintime_t	temp_throttle_delay;
108 	uint32_t	temp_throttle_reset_cnt;
109 	uint32_t	temp_throttle_trigger_cnt;
110 	uint32_t	temp_throttle_val;
111 };
112 
113 static struct imx6_anatop_softc *imx6_anatop_sc;
114 
115 /*
116  * Table of "operating points".
117  * These are combinations of frequency and voltage blessed by Freescale.
118  * While the datasheet says the ARM voltage can be as low as 925mV at
119  * 396MHz, it also says that the ARM and SOC voltages can't differ by
120  * more than 200mV, and the minimum SOC voltage is 1150mV, so that
121  * dictates the 950mV entry in this table.
122  */
123 static struct oppt {
124 	uint32_t	mhz;
125 	uint32_t	mv;
126 } imx6_oppt_table[] = {
127 	{ 396,	 950},
128 	{ 792,	1150},
129 	{ 852,	1225},
130 	{ 996,	1225},
131 	{1200,	1275},
132 };
133 
134 /*
135  * Table of CPU max frequencies.  This is used to translate the max frequency
136  * value (0-3) from the ocotp CFG3 register into a mhz value that can be looked
137  * up in the operating points table.
138  */
139 static uint32_t imx6_ocotp_mhz_tab[] = {792, 852, 996, 1200};
140 
141 #define	TZ_ZEROC	2731	/* deci-Kelvin <-> deci-Celsius offset. */
142 
143 uint32_t
144 imx6_anatop_read_4(bus_size_t offset)
145 {
146 
147 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_read_4 sc NULL"));
148 
149 	return (bus_read_4(imx6_anatop_sc->res[MEMRES], offset));
150 }
151 
152 void
153 imx6_anatop_write_4(bus_size_t offset, uint32_t value)
154 {
155 
156 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_write_4 sc NULL"));
157 
158 	bus_write_4(imx6_anatop_sc->res[MEMRES], offset, value);
159 }
160 
161 static void
162 vdd_set(struct imx6_anatop_softc *sc, int mv)
163 {
164 	int newtarg, newtargSoc, oldtarg;
165 	uint32_t delay, pmureg;
166 	static boolean_t init_done = false;
167 
168 	/*
169 	 * The datasheet says VDD_PU and VDD_SOC must be equal, and VDD_ARM
170 	 * can't be more than 50mV above or 200mV below them.  We keep them the
171 	 * same except in the case of the lowest operating point, which is
172 	 * handled as a special case below.
173 	 */
174 
175 	pmureg = imx6_anatop_read_4(IMX6_ANALOG_PMU_REG_CORE);
176 	oldtarg = pmureg & IMX6_ANALOG_PMU_REG0_TARG_MASK;
177 
178 	/* Convert mV to target value.  Clamp target to valid range. */
179 	if (mv < 725)
180 		newtarg = 0x00;
181 	else if (mv > 1450)
182 		newtarg = 0x1F;
183 	else
184 		newtarg = (mv - 700) / 25;
185 
186 	/*
187 	 * The SOC voltage can't go below 1150mV, and thus because of the 200mV
188 	 * rule, the ARM voltage can't go below 950mV.  The 950 is encoded in
189 	 * our oppt table, here we handle the SOC 1150 rule as a special case.
190 	 * (1150-700/25=18).
191 	 */
192 	newtargSoc = (newtarg < 18) ? 18 : newtarg;
193 
194 	/*
195 	 * The first time through the 3 voltages might not be equal so use a
196 	 * long conservative delay.  After that we need to delay 3uS for every
197 	 * 25mV step upward; we actually delay 6uS because empirically, it works
198 	 * and the 3uS per step recommended by the docs doesn't (3uS fails when
199 	 * going from 400->1200, but works for smaller changes).
200 	 */
201 	if (init_done) {
202 		if (newtarg == oldtarg)
203 			return;
204 		else if (newtarg > oldtarg)
205 			delay = (newtarg - oldtarg) * 6;
206 		else
207 			delay = 0;
208 	} else {
209 		delay = (700 / 25) * 6;
210 		init_done = true;
211 	}
212 
213 	/*
214 	 * Make the change and wait for it to take effect.
215 	 */
216 	pmureg &= ~(IMX6_ANALOG_PMU_REG0_TARG_MASK |
217 	    IMX6_ANALOG_PMU_REG1_TARG_MASK |
218 	    IMX6_ANALOG_PMU_REG2_TARG_MASK);
219 
220 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG0_TARG_SHIFT;
221 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG1_TARG_SHIFT;
222 	pmureg |= newtargSoc << IMX6_ANALOG_PMU_REG2_TARG_SHIFT;
223 
224 	imx6_anatop_write_4(IMX6_ANALOG_PMU_REG_CORE, pmureg);
225 	DELAY(delay);
226 	sc->cpu_curmv = newtarg * 25 + 700;
227 }
228 
229 static inline uint32_t
230 cpufreq_mhz_from_div(struct imx6_anatop_softc *sc, uint32_t corediv,
231     uint32_t plldiv)
232 {
233 
234 	return ((sc->refosc_mhz * (plldiv / 2)) / (corediv + 1));
235 }
236 
237 static inline void
238 cpufreq_mhz_to_div(struct imx6_anatop_softc *sc, uint32_t cpu_mhz,
239     uint32_t *corediv, uint32_t *plldiv)
240 {
241 
242 	*corediv = (cpu_mhz < 650) ? 1 : 0;
243 	*plldiv = ((*corediv + 1) * cpu_mhz) / (sc->refosc_mhz / 2);
244 }
245 
246 static inline uint32_t
247 cpufreq_actual_mhz(struct imx6_anatop_softc *sc, uint32_t cpu_mhz)
248 {
249 	uint32_t corediv, plldiv;
250 
251 	cpufreq_mhz_to_div(sc, cpu_mhz, &corediv, &plldiv);
252 	return (cpufreq_mhz_from_div(sc, corediv, plldiv));
253 }
254 
255 static struct oppt *
256 cpufreq_nearest_oppt(struct imx6_anatop_softc *sc, uint32_t cpu_newmhz)
257 {
258 	int d, diff, i, nearest;
259 
260 	if (cpu_newmhz > sc->cpu_maxmhz_hw && !sc->cpu_overclock_enable)
261 		cpu_newmhz = sc->cpu_maxmhz_hw;
262 
263 	diff = INT_MAX;
264 	nearest = 0;
265 	for (i = 0; i < nitems(imx6_oppt_table); ++i) {
266 		d = abs((int)cpu_newmhz - (int)imx6_oppt_table[i].mhz);
267 		if (diff > d) {
268 			diff = d;
269 			nearest = i;
270 		}
271 	}
272 	return (&imx6_oppt_table[nearest]);
273 }
274 
275 static void
276 cpufreq_set_clock(struct imx6_anatop_softc * sc, struct oppt *op)
277 {
278 	uint32_t corediv, plldiv, timeout, wrk32;
279 
280 	/* If increasing the frequency, we must first increase the voltage. */
281 	if (op->mhz > sc->cpu_curmhz) {
282 		vdd_set(sc, op->mv);
283 	}
284 
285 	/*
286 	 * I can't find a documented procedure for changing the ARM PLL divisor,
287 	 * but some trial and error came up with this:
288 	 *  - Set the bypass clock source to REF_CLK_24M (source #0).
289 	 *  - Set the PLL into bypass mode; cpu should now be running at 24mhz.
290 	 *  - Change the divisor.
291 	 *  - Wait for the LOCK bit to come on; it takes ~50 loop iterations.
292 	 *  - Turn off bypass mode; cpu should now be running at the new speed.
293 	 */
294 	cpufreq_mhz_to_div(sc, op->mhz, &corediv, &plldiv);
295 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
296 	    IMX6_ANALOG_CCM_PLL_ARM_CLK_SRC_MASK);
297 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_SET,
298 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
299 
300 	wrk32 = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM);
301 	wrk32 &= ~IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
302 	wrk32 |= plldiv;
303 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM, wrk32);
304 
305 	timeout = 10000;
306 	while ((imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
307 	    IMX6_ANALOG_CCM_PLL_ARM_LOCK) == 0)
308 		if (--timeout == 0)
309 			panic("imx6_set_cpu_clock(): PLL never locked");
310 
311 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
312 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
313 	imx_ccm_set_cacrr(corediv);
314 
315 	/* If lowering the frequency, it is now safe to lower the voltage. */
316 	if (op->mhz < sc->cpu_curmhz)
317 		vdd_set(sc, op->mv);
318 	sc->cpu_curmhz = op->mhz;
319 
320 	/* Tell the mpcore timer that its frequency has changed. */
321 	arm_tmr_change_frequency(
322 	    cpufreq_actual_mhz(sc, sc->cpu_curmhz) * 1000000 / 2);
323 }
324 
325 static int
326 cpufreq_sysctl_minmhz(SYSCTL_HANDLER_ARGS)
327 {
328 	struct imx6_anatop_softc *sc;
329 	struct oppt * op;
330 	uint32_t temp;
331 	int err;
332 
333 	sc = arg1;
334 
335 	temp = sc->cpu_minmhz;
336 	err = sysctl_handle_int(oidp, &temp, 0, req);
337 	if (err != 0 || req->newptr == NULL)
338 		return (err);
339 
340 	op = cpufreq_nearest_oppt(sc, temp);
341 	if (op->mhz > sc->cpu_maxmhz)
342 		return (ERANGE);
343 	else if (op->mhz == sc->cpu_minmhz)
344 		return (0);
345 
346 	/*
347 	 * Value changed, update softc.  If the new min is higher than the
348 	 * current speed, raise the current speed to match.
349 	 */
350 	sc->cpu_minmhz = op->mhz;
351 	if (sc->cpu_minmhz > sc->cpu_curmhz) {
352 		cpufreq_set_clock(sc, op);
353 	}
354 	return (err);
355 }
356 
357 static int
358 cpufreq_sysctl_maxmhz(SYSCTL_HANDLER_ARGS)
359 {
360 	struct imx6_anatop_softc *sc;
361 	struct oppt * op;
362 	uint32_t temp;
363 	int err;
364 
365 	sc = arg1;
366 
367 	temp = sc->cpu_maxmhz;
368 	err = sysctl_handle_int(oidp, &temp, 0, req);
369 	if (err != 0 || req->newptr == NULL)
370 		return (err);
371 
372 	op = cpufreq_nearest_oppt(sc, temp);
373 	if (op->mhz < sc->cpu_minmhz)
374 		return (ERANGE);
375 	else if (op->mhz == sc->cpu_maxmhz)
376 		return (0);
377 
378 	/*
379 	 *  Value changed, update softc and hardware.  The hardware update is
380 	 *  unconditional.  We always try to run at max speed, so any change of
381 	 *  the max means we need to change the current speed too, regardless of
382 	 *  whether it is higher or lower than the old max.
383 	 */
384 	sc->cpu_maxmhz = op->mhz;
385 	cpufreq_set_clock(sc, op);
386 
387 	return (err);
388 }
389 
390 static void
391 cpufreq_initialize(struct imx6_anatop_softc *sc)
392 {
393 	uint32_t cfg3speed;
394 	struct oppt * op;
395 
396 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
397 	    OID_AUTO, "cpu_mhz", CTLFLAG_RD, &sc->cpu_curmhz, 0,
398 	    "CPU frequency");
399 
400 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
401 	    OID_AUTO, "cpu_minmhz",
402 	    CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_NEEDGIANT,
403 	    sc, 0, cpufreq_sysctl_minmhz, "IU", "Minimum CPU frequency");
404 
405 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
406 	    OID_AUTO, "cpu_maxmhz",
407 	    CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_NEEDGIANT,
408 	    sc, 0, cpufreq_sysctl_maxmhz, "IU", "Maximum CPU frequency");
409 
410 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
411 	    OID_AUTO, "cpu_maxmhz_hw", CTLFLAG_RD, &sc->cpu_maxmhz_hw, 0,
412 	    "Maximum CPU frequency allowed by hardware");
413 
414 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
415 	    OID_AUTO, "cpu_overclock_enable", CTLFLAG_RWTUN,
416 	    &sc->cpu_overclock_enable, 0,
417 	    "Allow setting CPU frequency higher than cpu_maxmhz_hw");
418 
419 	/*
420 	 * XXX 24mhz shouldn't be hard-coded, should get this from imx6_ccm
421 	 * (even though in the real world it will always be 24mhz).  Oh wait a
422 	 * sec, I never wrote imx6_ccm.
423 	 */
424 	sc->refosc_mhz = 24;
425 
426 	/*
427 	 * Get the maximum speed this cpu can be set to.  The values in the
428 	 * OCOTP CFG3 register are not documented in the reference manual.
429 	 * The following info was in an archived email found via web search:
430 	 *   - 2b'11: 1200000000Hz;
431 	 *   - 2b'10: 996000000Hz;
432 	 *   - 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
433 	 *   - 2b'00: 792000000Hz;
434 	 * The default hardware max speed can be overridden by a tunable.
435 	 */
436 	cfg3speed = (fsl_ocotp_read_4(FSL_OCOTP_CFG3) &
437 	    FSL_OCOTP_CFG3_SPEED_MASK) >> FSL_OCOTP_CFG3_SPEED_SHIFT;
438 	sc->cpu_maxmhz_hw = imx6_ocotp_mhz_tab[cfg3speed];
439 	sc->cpu_maxmhz = sc->cpu_maxmhz_hw;
440 
441 	TUNABLE_INT_FETCH("hw.imx6.cpu_minmhz", &sc->cpu_minmhz);
442 	op = cpufreq_nearest_oppt(sc, sc->cpu_minmhz);
443 	sc->cpu_minmhz = op->mhz;
444 	sc->cpu_minmv = op->mv;
445 
446 	TUNABLE_INT_FETCH("hw.imx6.cpu_maxmhz", &sc->cpu_maxmhz);
447 	op = cpufreq_nearest_oppt(sc, sc->cpu_maxmhz);
448 	sc->cpu_maxmhz = op->mhz;
449 	sc->cpu_maxmv = op->mv;
450 
451 	/*
452 	 * Set the CPU to maximum speed.
453 	 *
454 	 * We won't have thermal throttling until interrupts are enabled, but we
455 	 * want to run at full speed through all the device init stuff.  This
456 	 * basically assumes that a single core can't overheat before interrupts
457 	 * are enabled; empirical testing shows that to be a safe assumption.
458 	 */
459 	cpufreq_set_clock(sc, op);
460 }
461 
462 static inline uint32_t
463 temp_from_count(struct imx6_anatop_softc *sc, uint32_t count)
464 {
465 
466 	return (((sc->temp_high_val - (count - sc->temp_high_cnt) *
467 	    (sc->temp_high_val - 250) /
468 	    (sc->temp_room_cnt - sc->temp_high_cnt))));
469 }
470 
471 static inline uint32_t
472 temp_to_count(struct imx6_anatop_softc *sc, uint32_t temp)
473 {
474 
475 	return ((sc->temp_room_cnt - sc->temp_high_cnt) *
476 	    (sc->temp_high_val - temp) / (sc->temp_high_val - 250) +
477 	    sc->temp_high_cnt);
478 }
479 
480 static void
481 temp_update_count(struct imx6_anatop_softc *sc)
482 {
483 	uint32_t val;
484 
485 	val = imx6_anatop_read_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0);
486 	if (!(val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_VALID))
487 		return;
488 	sc->temp_last_cnt =
489 	    (val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_MASK) >>
490 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_SHIFT;
491 }
492 
493 static int
494 temp_sysctl_handler(SYSCTL_HANDLER_ARGS)
495 {
496 	struct imx6_anatop_softc *sc = arg1;
497 	uint32_t t;
498 
499 	temp_update_count(sc);
500 
501 	t = temp_from_count(sc, sc->temp_last_cnt) + TZ_ZEROC;
502 
503 	return (sysctl_handle_int(oidp, &t, 0, req));
504 }
505 
506 static int
507 temp_throttle_sysctl_handler(SYSCTL_HANDLER_ARGS)
508 {
509 	struct imx6_anatop_softc *sc = arg1;
510 	int err;
511 	uint32_t temp;
512 
513 	temp = sc->temp_throttle_val + TZ_ZEROC;
514 	err = sysctl_handle_int(oidp, &temp, 0, req);
515 	if (temp < TZ_ZEROC)
516 		return (ERANGE);
517 	temp -= TZ_ZEROC;
518 	if (err != 0 || req->newptr == NULL || temp == sc->temp_throttle_val)
519 		return (err);
520 
521 	/* Value changed, update counts in softc and hardware. */
522 	sc->temp_throttle_val = temp;
523 	sc->temp_throttle_trigger_cnt = temp_to_count(sc, sc->temp_throttle_val);
524 	sc->temp_throttle_reset_cnt = temp_to_count(sc, sc->temp_throttle_val - 100);
525 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_CLR,
526 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_MASK);
527 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_SET,
528 	    (sc->temp_throttle_trigger_cnt <<
529 	     IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT));
530 	return (err);
531 }
532 
533 static void
534 tempmon_gofast(struct imx6_anatop_softc *sc)
535 {
536 
537 	if (sc->cpu_curmhz < sc->cpu_maxmhz) {
538 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_maxmhz));
539 	}
540 }
541 
542 static void
543 tempmon_goslow(struct imx6_anatop_softc *sc)
544 {
545 
546 	if (sc->cpu_curmhz > sc->cpu_minmhz) {
547 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_minmhz));
548 	}
549 }
550 
551 static int
552 tempmon_intr(void *arg)
553 {
554 	struct imx6_anatop_softc *sc = arg;
555 
556 	/*
557 	 * XXX Note that this code doesn't currently run (for some mysterious
558 	 * reason we just never get an interrupt), so the real monitoring is
559 	 * done by tempmon_throttle_check().
560 	 */
561 	tempmon_goslow(sc);
562 	/* XXX Schedule callout to speed back up eventually. */
563 	return (FILTER_HANDLED);
564 }
565 
566 static void
567 tempmon_throttle_check(void *arg)
568 {
569 	struct imx6_anatop_softc *sc = arg;
570 
571 	/* Lower counts are higher temperatures. */
572 	if (sc->temp_last_cnt < sc->temp_throttle_trigger_cnt)
573 		tempmon_goslow(sc);
574 	else if (sc->temp_last_cnt > (sc->temp_throttle_reset_cnt))
575 		tempmon_gofast(sc);
576 
577 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
578 		0, tempmon_throttle_check, sc, 0);
579 
580 }
581 
582 static void
583 initialize_tempmon(struct imx6_anatop_softc *sc)
584 {
585 	uint32_t cal;
586 
587 	/*
588 	 * Fetch calibration data: a sensor count at room temperature (25C),
589 	 * a sensor count at a high temperature, and that temperature
590 	 */
591 	cal = fsl_ocotp_read_4(FSL_OCOTP_ANA1);
592 	sc->temp_room_cnt = (cal & 0xFFF00000) >> 20;
593 	sc->temp_high_cnt = (cal & 0x000FFF00) >> 8;
594 	sc->temp_high_val = (cal & 0x000000FF) * 10;
595 
596 	/*
597 	 * Throttle to a lower cpu freq at 10C below the "hot" temperature, and
598 	 * reset back to max cpu freq at 5C below the trigger.
599 	 */
600 	sc->temp_throttle_val = sc->temp_high_val - 100;
601 	sc->temp_throttle_trigger_cnt =
602 	    temp_to_count(sc, sc->temp_throttle_val);
603 	sc->temp_throttle_reset_cnt =
604 	    temp_to_count(sc, sc->temp_throttle_val - 50);
605 
606 	/*
607 	 * Set the sensor to sample automatically at 16Hz (32.768KHz/0x800), set
608 	 * the throttle count, and begin making measurements.
609 	 */
610 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE1, 0x0800);
611 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0,
612 	    (sc->temp_throttle_trigger_cnt <<
613 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT) |
614 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_MEASURE);
615 
616 	/*
617 	 * XXX Note that the alarm-interrupt feature isn't working yet, so
618 	 * we'll use a callout handler to check at 10Hz.  Make sure we have an
619 	 * initial temperature reading before starting up the callouts so we
620 	 * don't get a bogus reading of zero.
621 	 */
622 	while (sc->temp_last_cnt == 0)
623 		temp_update_count(sc);
624 	sc->temp_throttle_delay = 100 * SBT_1MS;
625 	callout_init(&sc->temp_throttle_callout, 0);
626 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
627 	    0, tempmon_throttle_check, sc, 0);
628 
629 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
630 	    OID_AUTO, "temperature",
631 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
632 	    temp_sysctl_handler, "IK", "Current die temperature");
633 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
634 	    OID_AUTO, "throttle_temperature",
635 	    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc,
636 	    0, temp_throttle_sysctl_handler, "IK",
637 	    "Throttle CPU when exceeding this temperature");
638 }
639 
640 static void
641 intr_setup(void *arg)
642 {
643 	int rid;
644 	struct imx6_anatop_softc *sc;
645 
646 	sc = arg;
647 	rid = 0;
648 	sc->res[IRQRES] = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ, &rid,
649 	    RF_ACTIVE);
650 	if (sc->res[IRQRES] != NULL) {
651 		bus_setup_intr(sc->dev, sc->res[IRQRES],
652 		    INTR_TYPE_MISC | INTR_MPSAFE, tempmon_intr, NULL, sc,
653 		    &sc->temp_intrhand);
654 	} else {
655 		device_printf(sc->dev, "Cannot allocate IRQ resource\n");
656 	}
657 	config_intrhook_disestablish(&sc->intr_setup_hook);
658 }
659 
660 static void
661 imx6_anatop_new_pass(device_t dev)
662 {
663 	struct imx6_anatop_softc *sc;
664 	const int cpu_init_pass = BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE;
665 
666 	/*
667 	 * We attach during BUS_PASS_BUS (because some day we will be a
668 	 * simplebus that has regulator devices as children), but some of our
669 	 * init work cannot be done until BUS_PASS_CPU (we rely on other devices
670 	 * that attach on the CPU pass).
671 	 */
672 	sc = device_get_softc(dev);
673 	if (!sc->cpu_init_done && bus_current_pass >= cpu_init_pass) {
674 		sc->cpu_init_done = true;
675 		cpufreq_initialize(sc);
676 		initialize_tempmon(sc);
677 		if (bootverbose) {
678 			device_printf(sc->dev, "CPU %uMHz @ %umV\n",
679 			    sc->cpu_curmhz, sc->cpu_curmv);
680 		}
681 	}
682 	bus_generic_new_pass(dev);
683 }
684 
685 static int
686 imx6_anatop_detach(device_t dev)
687 {
688 
689 	/* This device can never detach. */
690 	return (EBUSY);
691 }
692 
693 static int
694 imx6_anatop_attach(device_t dev)
695 {
696 	struct imx6_anatop_softc *sc;
697 	int err;
698 
699 	sc = device_get_softc(dev);
700 	sc->dev = dev;
701 
702 	/* Allocate bus_space resources. */
703 	if (bus_alloc_resources(dev, imx6_anatop_spec, sc->res)) {
704 		device_printf(dev, "Cannot allocate resources\n");
705 		err = ENXIO;
706 		goto out;
707 	}
708 
709 	sc->intr_setup_hook.ich_func = intr_setup;
710 	sc->intr_setup_hook.ich_arg = sc;
711 	config_intrhook_establish(&sc->intr_setup_hook);
712 
713 	SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
714 	    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev)),
715 	    OID_AUTO, "cpu_voltage", CTLFLAG_RD,
716 	    &sc->cpu_curmv, 0, "Current CPU voltage in millivolts");
717 
718 	imx6_anatop_sc = sc;
719 
720 	/*
721 	 * Other code seen on the net sets this SELFBIASOFF flag around the same
722 	 * time the temperature sensor is set up, although it's unclear how the
723 	 * two are related (if at all).
724 	 */
725 	imx6_anatop_write_4(IMX6_ANALOG_PMU_MISC0_SET,
726 	    IMX6_ANALOG_PMU_MISC0_SELFBIASOFF);
727 
728 	/*
729 	 * Some day, when we're ready to deal with the actual anatop regulators
730 	 * that are described in fdt data as children of this "bus", this would
731 	 * be the place to invoke a simplebus helper routine to instantiate the
732 	 * children from the fdt data.
733 	 */
734 
735 	err = 0;
736 
737 out:
738 
739 	if (err != 0) {
740 		bus_release_resources(dev, imx6_anatop_spec, sc->res);
741 	}
742 
743 	return (err);
744 }
745 
746 uint32_t
747 pll4_configure_output(uint32_t mfi, uint32_t mfn, uint32_t mfd)
748 {
749 	int reg;
750 
751 	/*
752 	 * Audio PLL (PLL4).
753 	 * PLL output frequency = Fref * (DIV_SELECT + NUM/DENOM)
754 	 */
755 
756 	reg = (IMX6_ANALOG_CCM_PLL_AUDIO_ENABLE);
757 	reg &= ~(IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_MASK << \
758 		IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
759 	reg |= (mfi << IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
760 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO, reg);
761 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_NUM, mfn);
762 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_DENOM, mfd);
763 
764 	return (0);
765 }
766 
767 static int
768 imx6_anatop_probe(device_t dev)
769 {
770 
771 	if (!ofw_bus_status_okay(dev))
772 		return (ENXIO);
773 
774 	if (ofw_bus_is_compatible(dev, "fsl,imx6q-anatop") == 0)
775 		return (ENXIO);
776 
777 	device_set_desc(dev, "Freescale i.MX6 Analog PLLs and Power");
778 
779 	return (BUS_PROBE_DEFAULT);
780 }
781 
782 uint32_t
783 imx6_get_cpu_clock(void)
784 {
785 	uint32_t corediv, plldiv;
786 
787 	corediv = imx_ccm_get_cacrr();
788 	plldiv = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
789 	    IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
790 	return (cpufreq_mhz_from_div(imx6_anatop_sc, corediv, plldiv));
791 }
792 
793 static device_method_t imx6_anatop_methods[] = {
794 	/* Device interface */
795 	DEVMETHOD(device_probe,  imx6_anatop_probe),
796 	DEVMETHOD(device_attach, imx6_anatop_attach),
797 	DEVMETHOD(device_detach, imx6_anatop_detach),
798 
799 	/* Bus interface */
800 	DEVMETHOD(bus_new_pass,  imx6_anatop_new_pass),
801 
802 	DEVMETHOD_END
803 };
804 
805 static driver_t imx6_anatop_driver = {
806 	"imx6_anatop",
807 	imx6_anatop_methods,
808 	sizeof(struct imx6_anatop_softc)
809 };
810 
811 EARLY_DRIVER_MODULE(imx6_anatop, simplebus, imx6_anatop_driver, 0, 0,
812     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
813 EARLY_DRIVER_MODULE(imx6_anatop, ofwbus, imx6_anatop_driver, 0, 0,
814     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
815