xref: /freebsd/sys/arm/freescale/imx/imx6_anatop.c (revision 43faedc1339a9624c7acedb7f3e5624e64da5b99)
1 /*-
2  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
3  * Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
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-Celcius, 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 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
82 	{ -1, 0 }
83 };
84 #define	MEMRES	0
85 #define	IRQRES	1
86 
87 struct imx6_anatop_softc {
88 	device_t	dev;
89 	struct resource	*res[2];
90 	struct intr_config_hook
91 			intr_setup_hook;
92 	uint32_t	cpu_curmhz;
93 	uint32_t	cpu_curmv;
94 	uint32_t	cpu_minmhz;
95 	uint32_t	cpu_minmv;
96 	uint32_t	cpu_maxmhz;
97 	uint32_t	cpu_maxmv;
98 	uint32_t	cpu_maxmhz_hw;
99 	boolean_t	cpu_overclock_enable;
100 	boolean_t	cpu_init_done;
101 	uint32_t	refosc_mhz;
102 	void		*temp_intrhand;
103 	uint32_t	temp_high_val;
104 	uint32_t	temp_high_cnt;
105 	uint32_t	temp_last_cnt;
106 	uint32_t	temp_room_cnt;
107 	struct callout	temp_throttle_callout;
108 	sbintime_t	temp_throttle_delay;
109 	uint32_t	temp_throttle_reset_cnt;
110 	uint32_t	temp_throttle_trigger_cnt;
111 	uint32_t	temp_throttle_val;
112 };
113 
114 static struct imx6_anatop_softc *imx6_anatop_sc;
115 
116 /*
117  * Table of "operating points".
118  * These are combinations of frequency and voltage blessed by Freescale.
119  * While the datasheet says the ARM voltage can be as low as 925mV at
120  * 396MHz, it also says that the ARM and SOC voltages can't differ by
121  * more than 200mV, and the minimum SOC voltage is 1150mV, so that
122  * dictates the 950mV entry in this table.
123  */
124 static struct oppt {
125 	uint32_t	mhz;
126 	uint32_t	mv;
127 } imx6_oppt_table[] = {
128 	{ 396,	 950},
129 	{ 792,	1150},
130 	{ 852,	1225},
131 	{ 996,	1225},
132 	{1200,	1275},
133 };
134 
135 /*
136  * Table of CPU max frequencies.  This is used to translate the max frequency
137  * value (0-3) from the ocotp CFG3 register into a mhz value that can be looked
138  * up in the operating points table.
139  */
140 static uint32_t imx6_ocotp_mhz_tab[] = {792, 852, 996, 1200};
141 
142 #define	TZ_ZEROC	2732	/* deci-Kelvin <-> deci-Celcius offset. */
143 
144 uint32_t
145 imx6_anatop_read_4(bus_size_t offset)
146 {
147 
148 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_read_4 sc NULL"));
149 
150 	return (bus_read_4(imx6_anatop_sc->res[MEMRES], offset));
151 }
152 
153 void
154 imx6_anatop_write_4(bus_size_t offset, uint32_t value)
155 {
156 
157 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_write_4 sc NULL"));
158 
159 	bus_write_4(imx6_anatop_sc->res[MEMRES], offset, value);
160 }
161 
162 static void
163 vdd_set(struct imx6_anatop_softc *sc, int mv)
164 {
165 	int newtarg, newtargSoc, oldtarg;
166 	uint32_t delay, pmureg;
167 	static boolean_t init_done = false;
168 
169 	/*
170 	 * The datasheet says VDD_PU and VDD_SOC must be equal, and VDD_ARM
171 	 * can't be more than 50mV above or 200mV below them.  We keep them the
172 	 * same except in the case of the lowest operating point, which is
173 	 * handled as a special case below.
174 	 */
175 
176 	pmureg = imx6_anatop_read_4(IMX6_ANALOG_PMU_REG_CORE);
177 	oldtarg = pmureg & IMX6_ANALOG_PMU_REG0_TARG_MASK;
178 
179 	/* Convert mV to target value.  Clamp target to valid range. */
180 	if (mv < 725)
181 		newtarg = 0x00;
182 	else if (mv > 1450)
183 		newtarg = 0x1F;
184 	else
185 		newtarg = (mv - 700) / 25;
186 
187 	/*
188 	 * The SOC voltage can't go below 1150mV, and thus because of the 200mV
189 	 * rule, the ARM voltage can't go below 950mV.  The 950 is encoded in
190 	 * our oppt table, here we handle the SOC 1150 rule as a special case.
191 	 * (1150-700/25=18).
192 	 */
193 	newtargSoc = (newtarg < 18) ? 18 : newtarg;
194 
195 	/*
196 	 * The first time through the 3 voltages might not be equal so use a
197 	 * long conservative delay.  After that we need to delay 3uS for every
198 	 * 25mV step upward; we actually delay 6uS because empirically, it works
199 	 * and the 3uS per step recommended by the docs doesn't (3uS fails when
200 	 * going from 400->1200, but works for smaller changes).
201 	 */
202 	if (init_done) {
203 		if (newtarg == oldtarg)
204 			return;
205 		else if (newtarg > oldtarg)
206 			delay = (newtarg - oldtarg) * 6;
207 		else
208 			delay = 0;
209 	} else {
210 		delay = (700 / 25) * 6;
211 		init_done = true;
212 	}
213 
214 	/*
215 	 * Make the change and wait for it to take effect.
216 	 */
217 	pmureg &= ~(IMX6_ANALOG_PMU_REG0_TARG_MASK |
218 	    IMX6_ANALOG_PMU_REG1_TARG_MASK |
219 	    IMX6_ANALOG_PMU_REG2_TARG_MASK);
220 
221 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG0_TARG_SHIFT;
222 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG1_TARG_SHIFT;
223 	pmureg |= newtargSoc << IMX6_ANALOG_PMU_REG2_TARG_SHIFT;
224 
225 	imx6_anatop_write_4(IMX6_ANALOG_PMU_REG_CORE, pmureg);
226 	DELAY(delay);
227 	sc->cpu_curmv = newtarg * 25 + 700;
228 }
229 
230 static inline uint32_t
231 cpufreq_mhz_from_div(struct imx6_anatop_softc *sc, uint32_t corediv,
232     uint32_t plldiv)
233 {
234 
235 	return ((sc->refosc_mhz * (plldiv / 2)) / (corediv + 1));
236 }
237 
238 static inline void
239 cpufreq_mhz_to_div(struct imx6_anatop_softc *sc, uint32_t cpu_mhz,
240     uint32_t *corediv, uint32_t *plldiv)
241 {
242 
243 	*corediv = (cpu_mhz < 650) ? 1 : 0;
244 	*plldiv = ((*corediv + 1) * cpu_mhz) / (sc->refosc_mhz / 2);
245 }
246 
247 static inline uint32_t
248 cpufreq_actual_mhz(struct imx6_anatop_softc *sc, uint32_t cpu_mhz)
249 {
250 	uint32_t corediv, plldiv;
251 
252 	cpufreq_mhz_to_div(sc, cpu_mhz, &corediv, &plldiv);
253 	return (cpufreq_mhz_from_div(sc, corediv, plldiv));
254 }
255 
256 static struct oppt *
257 cpufreq_nearest_oppt(struct imx6_anatop_softc *sc, uint32_t cpu_newmhz)
258 {
259 	int d, diff, i, nearest;
260 
261 	if (cpu_newmhz > sc->cpu_maxmhz_hw && !sc->cpu_overclock_enable)
262 		cpu_newmhz = sc->cpu_maxmhz_hw;
263 
264 	diff = INT_MAX;
265 	nearest = 0;
266 	for (i = 0; i < nitems(imx6_oppt_table); ++i) {
267 		d = abs((int)cpu_newmhz - (int)imx6_oppt_table[i].mhz);
268 		if (diff > d) {
269 			diff = d;
270 			nearest = i;
271 		}
272 	}
273 	return (&imx6_oppt_table[nearest]);
274 }
275 
276 static void
277 cpufreq_set_clock(struct imx6_anatop_softc * sc, struct oppt *op)
278 {
279 	uint32_t corediv, plldiv, timeout, wrk32;
280 
281 	/* If increasing the frequency, we must first increase the voltage. */
282 	if (op->mhz > sc->cpu_curmhz) {
283 		vdd_set(sc, op->mv);
284 	}
285 
286 	/*
287 	 * I can't find a documented procedure for changing the ARM PLL divisor,
288 	 * but some trial and error came up with this:
289 	 *  - Set the bypass clock source to REF_CLK_24M (source #0).
290 	 *  - Set the PLL into bypass mode; cpu should now be running at 24mhz.
291 	 *  - Change the divisor.
292 	 *  - Wait for the LOCK bit to come on; it takes ~50 loop iterations.
293 	 *  - Turn off bypass mode; cpu should now be running at the new speed.
294 	 */
295 	cpufreq_mhz_to_div(sc, op->mhz, &corediv, &plldiv);
296 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
297 	    IMX6_ANALOG_CCM_PLL_ARM_CLK_SRC_MASK);
298 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_SET,
299 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
300 
301 	wrk32 = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM);
302 	wrk32 &= ~IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
303 	wrk32 |= plldiv;
304 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM, wrk32);
305 
306 	timeout = 10000;
307 	while ((imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
308 	    IMX6_ANALOG_CCM_PLL_ARM_LOCK) == 0)
309 		if (--timeout == 0)
310 			panic("imx6_set_cpu_clock(): PLL never locked");
311 
312 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
313 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
314 	imx_ccm_set_cacrr(corediv);
315 
316 	/* If lowering the frequency, it is now safe to lower the voltage. */
317 	if (op->mhz < sc->cpu_curmhz)
318 		vdd_set(sc, op->mv);
319 	sc->cpu_curmhz = op->mhz;
320 
321 	/* Tell the mpcore timer that its frequency has changed. */
322 	arm_tmr_change_frequency(
323 	    cpufreq_actual_mhz(sc, sc->cpu_curmhz) * 1000000 / 2);
324 }
325 
326 static int
327 cpufreq_sysctl_minmhz(SYSCTL_HANDLER_ARGS)
328 {
329 	struct imx6_anatop_softc *sc;
330 	struct oppt * op;
331 	uint32_t temp;
332 	int err;
333 
334 	sc = arg1;
335 
336 	temp = sc->cpu_minmhz;
337 	err = sysctl_handle_int(oidp, &temp, 0, req);
338 	if (err != 0 || req->newptr == NULL)
339 		return (err);
340 
341 	op = cpufreq_nearest_oppt(sc, temp);
342 	if (op->mhz > sc->cpu_maxmhz)
343 		return (ERANGE);
344 	else if (op->mhz == sc->cpu_minmhz)
345 		return (0);
346 
347 	/*
348 	 * Value changed, update softc.  If the new min is higher than the
349 	 * current speed, raise the current speed to match.
350 	 */
351 	sc->cpu_minmhz = op->mhz;
352 	if (sc->cpu_minmhz > sc->cpu_curmhz) {
353 		cpufreq_set_clock(sc, op);
354 	}
355 	return (err);
356 }
357 
358 static int
359 cpufreq_sysctl_maxmhz(SYSCTL_HANDLER_ARGS)
360 {
361 	struct imx6_anatop_softc *sc;
362 	struct oppt * op;
363 	uint32_t temp;
364 	int err;
365 
366 	sc = arg1;
367 
368 	temp = sc->cpu_maxmhz;
369 	err = sysctl_handle_int(oidp, &temp, 0, req);
370 	if (err != 0 || req->newptr == NULL)
371 		return (err);
372 
373 	op = cpufreq_nearest_oppt(sc, temp);
374 	if (op->mhz < sc->cpu_minmhz)
375 		return (ERANGE);
376 	else if (op->mhz == sc->cpu_maxmhz)
377 		return (0);
378 
379 	/*
380 	 *  Value changed, update softc and hardware.  The hardware update is
381 	 *  unconditional.  We always try to run at max speed, so any change of
382 	 *  the max means we need to change the current speed too, regardless of
383 	 *  whether it is higher or lower than the old max.
384 	 */
385 	sc->cpu_maxmhz = op->mhz;
386 	cpufreq_set_clock(sc, op);
387 
388 	return (err);
389 }
390 
391 static void
392 cpufreq_initialize(struct imx6_anatop_softc *sc)
393 {
394 	uint32_t cfg3speed;
395 	struct oppt * op;
396 
397 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
398 	    OID_AUTO, "cpu_mhz", CTLFLAG_RD, &sc->cpu_curmhz, 0,
399 	    "CPU frequency");
400 
401 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
402 	    OID_AUTO, "cpu_minmhz", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
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", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
407 	    sc, 0, cpufreq_sysctl_maxmhz, "IU", "Maximum CPU frequency");
408 
409 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
410 	    OID_AUTO, "cpu_maxmhz_hw", CTLFLAG_RD, &sc->cpu_maxmhz_hw, 0,
411 	    "Maximum CPU frequency allowed by hardware");
412 
413 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
414 	    OID_AUTO, "cpu_overclock_enable", CTLFLAG_RWTUN,
415 	    &sc->cpu_overclock_enable, 0,
416 	    "Allow setting CPU frequency higher than cpu_maxmhz_hw");
417 
418 	/*
419 	 * XXX 24mhz shouldn't be hard-coded, should get this from imx6_ccm
420 	 * (even though in the real world it will always be 24mhz).  Oh wait a
421 	 * sec, I never wrote imx6_ccm.
422 	 */
423 	sc->refosc_mhz = 24;
424 
425 	/*
426 	 * Get the maximum speed this cpu can be set to.  The values in the
427 	 * OCOTP CFG3 register are not documented in the reference manual.
428 	 * The following info was in an archived email found via web search:
429 	 *   - 2b'11: 1200000000Hz;
430 	 *   - 2b'10: 996000000Hz;
431 	 *   - 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
432 	 *   - 2b'00: 792000000Hz;
433 	 * The default hardware max speed can be overridden by a tunable.
434 	 */
435 	cfg3speed = (fsl_ocotp_read_4(FSL_OCOTP_CFG3) &
436 	    FSL_OCOTP_CFG3_SPEED_MASK) >> FSL_OCOTP_CFG3_SPEED_SHIFT;
437 	sc->cpu_maxmhz_hw = imx6_ocotp_mhz_tab[cfg3speed];
438 	sc->cpu_maxmhz = sc->cpu_maxmhz_hw;
439 
440 	TUNABLE_INT_FETCH("hw.imx6.cpu_minmhz", &sc->cpu_minmhz);
441 	op = cpufreq_nearest_oppt(sc, sc->cpu_minmhz);
442 	sc->cpu_minmhz = op->mhz;
443 	sc->cpu_minmv = op->mv;
444 
445 	TUNABLE_INT_FETCH("hw.imx6.cpu_maxmhz", &sc->cpu_maxmhz);
446 	op = cpufreq_nearest_oppt(sc, sc->cpu_maxmhz);
447 	sc->cpu_maxmhz = op->mhz;
448 	sc->cpu_maxmv = op->mv;
449 
450 	/*
451 	 * Set the CPU to maximum speed.
452 	 *
453 	 * We won't have thermal throttling until interrupts are enabled, but we
454 	 * want to run at full speed through all the device init stuff.  This
455 	 * basically assumes that a single core can't overheat before interrupts
456 	 * are enabled; empirical testing shows that to be a safe assumption.
457 	 */
458 	cpufreq_set_clock(sc, op);
459 }
460 
461 static inline uint32_t
462 temp_from_count(struct imx6_anatop_softc *sc, uint32_t count)
463 {
464 
465 	return (((sc->temp_high_val - (count - sc->temp_high_cnt) *
466 	    (sc->temp_high_val - 250) /
467 	    (sc->temp_room_cnt - sc->temp_high_cnt))));
468 }
469 
470 static inline uint32_t
471 temp_to_count(struct imx6_anatop_softc *sc, uint32_t temp)
472 {
473 
474 	return ((sc->temp_room_cnt - sc->temp_high_cnt) *
475 	    (sc->temp_high_val - temp) / (sc->temp_high_val - 250) +
476 	    sc->temp_high_cnt);
477 }
478 
479 static void
480 temp_update_count(struct imx6_anatop_softc *sc)
481 {
482 	uint32_t val;
483 
484 	val = imx6_anatop_read_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0);
485 	if (!(val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_VALID))
486 		return;
487 	sc->temp_last_cnt =
488 	    (val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_MASK) >>
489 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_SHIFT;
490 }
491 
492 static int
493 temp_sysctl_handler(SYSCTL_HANDLER_ARGS)
494 {
495 	struct imx6_anatop_softc *sc = arg1;
496 	uint32_t t;
497 
498 	temp_update_count(sc);
499 
500 	t = temp_from_count(sc, sc->temp_last_cnt) + TZ_ZEROC;
501 
502 	return (sysctl_handle_int(oidp, &t, 0, req));
503 }
504 
505 static int
506 temp_throttle_sysctl_handler(SYSCTL_HANDLER_ARGS)
507 {
508 	struct imx6_anatop_softc *sc = arg1;
509 	int err;
510 	uint32_t temp;
511 
512 	temp = sc->temp_throttle_val + TZ_ZEROC;
513 	err = sysctl_handle_int(oidp, &temp, 0, req);
514 	if (temp < TZ_ZEROC)
515 		return (ERANGE);
516 	temp -= TZ_ZEROC;
517 	if (err != 0 || req->newptr == NULL || temp == sc->temp_throttle_val)
518 		return (err);
519 
520 	/* Value changed, update counts in softc and hardware. */
521 	sc->temp_throttle_val = temp;
522 	sc->temp_throttle_trigger_cnt = temp_to_count(sc, sc->temp_throttle_val);
523 	sc->temp_throttle_reset_cnt = temp_to_count(sc, sc->temp_throttle_val - 100);
524 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_CLR,
525 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_MASK);
526 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_SET,
527 	    (sc->temp_throttle_trigger_cnt <<
528 	     IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT));
529 	return (err);
530 }
531 
532 static void
533 tempmon_gofast(struct imx6_anatop_softc *sc)
534 {
535 
536 	if (sc->cpu_curmhz < sc->cpu_maxmhz) {
537 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_maxmhz));
538 	}
539 }
540 
541 static void
542 tempmon_goslow(struct imx6_anatop_softc *sc)
543 {
544 
545 	if (sc->cpu_curmhz > sc->cpu_minmhz) {
546 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_minmhz));
547 	}
548 }
549 
550 static int
551 tempmon_intr(void *arg)
552 {
553 	struct imx6_anatop_softc *sc = arg;
554 
555 	/*
556 	 * XXX Note that this code doesn't currently run (for some mysterious
557 	 * reason we just never get an interrupt), so the real monitoring is
558 	 * done by tempmon_throttle_check().
559 	 */
560 	tempmon_goslow(sc);
561 	/* XXX Schedule callout to speed back up eventually. */
562 	return (FILTER_HANDLED);
563 }
564 
565 static void
566 tempmon_throttle_check(void *arg)
567 {
568 	struct imx6_anatop_softc *sc = arg;
569 
570 	/* Lower counts are higher temperatures. */
571 	if (sc->temp_last_cnt < sc->temp_throttle_trigger_cnt)
572 		tempmon_goslow(sc);
573 	else if (sc->temp_last_cnt > (sc->temp_throttle_reset_cnt))
574 		tempmon_gofast(sc);
575 
576 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
577 		0, tempmon_throttle_check, sc, 0);
578 
579 }
580 
581 static void
582 initialize_tempmon(struct imx6_anatop_softc *sc)
583 {
584 	uint32_t cal;
585 
586 	/*
587 	 * Fetch calibration data: a sensor count at room temperature (25C),
588 	 * a sensor count at a high temperature, and that temperature
589 	 */
590 	cal = fsl_ocotp_read_4(FSL_OCOTP_ANA1);
591 	sc->temp_room_cnt = (cal & 0xFFF00000) >> 20;
592 	sc->temp_high_cnt = (cal & 0x000FFF00) >> 8;
593 	sc->temp_high_val = (cal & 0x000000FF) * 10;
594 
595 	/*
596 	 * Throttle to a lower cpu freq at 10C below the "hot" temperature, and
597 	 * reset back to max cpu freq at 5C below the trigger.
598 	 */
599 	sc->temp_throttle_val = sc->temp_high_val - 100;
600 	sc->temp_throttle_trigger_cnt =
601 	    temp_to_count(sc, sc->temp_throttle_val);
602 	sc->temp_throttle_reset_cnt =
603 	    temp_to_count(sc, sc->temp_throttle_val - 50);
604 
605 	/*
606 	 * Set the sensor to sample automatically at 16Hz (32.768KHz/0x800), set
607 	 * the throttle count, and begin making measurements.
608 	 */
609 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE1, 0x0800);
610 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0,
611 	    (sc->temp_throttle_trigger_cnt <<
612 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT) |
613 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_MEASURE);
614 
615 	/*
616 	 * XXX Note that the alarm-interrupt feature isn't working yet, so
617 	 * we'll use a callout handler to check at 10Hz.  Make sure we have an
618 	 * initial temperature reading before starting up the callouts so we
619 	 * don't get a bogus reading of zero.
620 	 */
621 	while (sc->temp_last_cnt == 0)
622 		temp_update_count(sc);
623 	sc->temp_throttle_delay = 100 * SBT_1MS;
624 	callout_init(&sc->temp_throttle_callout, 0);
625 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
626 	    0, tempmon_throttle_check, sc, 0);
627 
628 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
629 	    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
630 	    temp_sysctl_handler, "IK", "Current die temperature");
631 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx),
632 	    OID_AUTO, "throttle_temperature", CTLTYPE_INT | CTLFLAG_RW, sc,
633 	    0, temp_throttle_sysctl_handler, "IK",
634 	    "Throttle CPU when exceeding this temperature");
635 }
636 
637 static void
638 intr_setup(void *arg)
639 {
640 	struct imx6_anatop_softc *sc;
641 
642 	sc = arg;
643 	bus_setup_intr(sc->dev, sc->res[IRQRES], INTR_TYPE_MISC | INTR_MPSAFE,
644 	    tempmon_intr, NULL, sc, &sc->temp_intrhand);
645 	config_intrhook_disestablish(&sc->intr_setup_hook);
646 }
647 
648 static void
649 imx6_anatop_new_pass(device_t dev)
650 {
651 	struct imx6_anatop_softc *sc;
652 	const int cpu_init_pass = BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE;
653 
654 	/*
655 	 * We attach during BUS_PASS_BUS (because some day we will be a
656 	 * simplebus that has regulator devices as children), but some of our
657 	 * init work cannot be done until BUS_PASS_CPU (we rely on other devices
658 	 * that attach on the CPU pass).
659 	 */
660 	sc = device_get_softc(dev);
661 	if (!sc->cpu_init_done && bus_current_pass >= cpu_init_pass) {
662 		sc->cpu_init_done = true;
663 		cpufreq_initialize(sc);
664 		initialize_tempmon(sc);
665 		if (bootverbose) {
666 			device_printf(sc->dev, "CPU %uMHz @ %umV\n",
667 			    sc->cpu_curmhz, sc->cpu_curmv);
668 		}
669 	}
670 	bus_generic_new_pass(dev);
671 }
672 
673 static int
674 imx6_anatop_detach(device_t dev)
675 {
676 
677 	/* This device can never detach. */
678 	return (EBUSY);
679 }
680 
681 static int
682 imx6_anatop_attach(device_t dev)
683 {
684 	struct imx6_anatop_softc *sc;
685 	int err;
686 
687 	sc = device_get_softc(dev);
688 	sc->dev = dev;
689 
690 	/* Allocate bus_space resources. */
691 	if (bus_alloc_resources(dev, imx6_anatop_spec, sc->res)) {
692 		device_printf(dev, "Cannot allocate resources\n");
693 		err = ENXIO;
694 		goto out;
695 	}
696 
697 	sc->intr_setup_hook.ich_func = intr_setup;
698 	sc->intr_setup_hook.ich_arg = sc;
699 	config_intrhook_establish(&sc->intr_setup_hook);
700 
701 	SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
702 	    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev)),
703 	    OID_AUTO, "cpu_voltage", CTLFLAG_RD,
704 	    &sc->cpu_curmv, 0, "Current CPU voltage in millivolts");
705 
706 	imx6_anatop_sc = sc;
707 
708 	/*
709 	 * Other code seen on the net sets this SELFBIASOFF flag around the same
710 	 * time the temperature sensor is set up, although it's unclear how the
711 	 * two are related (if at all).
712 	 */
713 	imx6_anatop_write_4(IMX6_ANALOG_PMU_MISC0_SET,
714 	    IMX6_ANALOG_PMU_MISC0_SELFBIASOFF);
715 
716 	/*
717 	 * Some day, when we're ready to deal with the actual anatop regulators
718 	 * that are described in fdt data as children of this "bus", this would
719 	 * be the place to invoke a simplebus helper routine to instantiate the
720 	 * children from the fdt data.
721 	 */
722 
723 	err = 0;
724 
725 out:
726 
727 	if (err != 0) {
728 		bus_release_resources(dev, imx6_anatop_spec, sc->res);
729 	}
730 
731 	return (err);
732 }
733 
734 uint32_t
735 pll4_configure_output(uint32_t mfi, uint32_t mfn, uint32_t mfd)
736 {
737 	int reg;
738 
739 	/*
740 	 * Audio PLL (PLL4).
741 	 * PLL output frequency = Fref * (DIV_SELECT + NUM/DENOM)
742 	 */
743 
744 	reg = (IMX6_ANALOG_CCM_PLL_AUDIO_ENABLE);
745 	reg &= ~(IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_MASK << \
746 		IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
747 	reg |= (mfi << IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
748 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO, reg);
749 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_NUM, mfn);
750 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_DENOM, mfd);
751 
752 	return (0);
753 }
754 
755 static int
756 imx6_anatop_probe(device_t dev)
757 {
758 
759 	if (!ofw_bus_status_okay(dev))
760 		return (ENXIO);
761 
762 	if (ofw_bus_is_compatible(dev, "fsl,imx6q-anatop") == 0)
763 		return (ENXIO);
764 
765 	device_set_desc(dev, "Freescale i.MX6 Analog PLLs and Power");
766 
767 	return (BUS_PROBE_DEFAULT);
768 }
769 
770 uint32_t
771 imx6_get_cpu_clock()
772 {
773 	uint32_t corediv, plldiv;
774 
775 	corediv = imx_ccm_get_cacrr();
776 	plldiv = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
777 	    IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
778 	return (cpufreq_mhz_from_div(imx6_anatop_sc, corediv, plldiv));
779 }
780 
781 static device_method_t imx6_anatop_methods[] = {
782 	/* Device interface */
783 	DEVMETHOD(device_probe,  imx6_anatop_probe),
784 	DEVMETHOD(device_attach, imx6_anatop_attach),
785 	DEVMETHOD(device_detach, imx6_anatop_detach),
786 
787 	/* Bus interface */
788 	DEVMETHOD(bus_new_pass,  imx6_anatop_new_pass),
789 
790 	DEVMETHOD_END
791 };
792 
793 static driver_t imx6_anatop_driver = {
794 	"imx6_anatop",
795 	imx6_anatop_methods,
796 	sizeof(struct imx6_anatop_softc)
797 };
798 
799 static devclass_t imx6_anatop_devclass;
800 
801 EARLY_DRIVER_MODULE(imx6_anatop, simplebus, imx6_anatop_driver,
802     imx6_anatop_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
803 EARLY_DRIVER_MODULE(imx6_anatop, ofwbus, imx6_anatop_driver,
804     imx6_anatop_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
805 
806