xref: /freebsd/sys/powerpc/powermac/smu.c (revision a3cf0ef5a295c885c895fabfd56470c0d1db322d)
1 /*-
2  * Copyright (c) 2009 Nathan Whitehorn
3  * All rights reserved.
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  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/systm.h>
34 #include <sys/module.h>
35 #include <sys/conf.h>
36 #include <sys/cpu.h>
37 #include <sys/clock.h>
38 #include <sys/ctype.h>
39 #include <sys/kernel.h>
40 #include <sys/kthread.h>
41 #include <sys/reboot.h>
42 #include <sys/rman.h>
43 #include <sys/sysctl.h>
44 #include <sys/unistd.h>
45 
46 #include <machine/bus.h>
47 #include <machine/intr_machdep.h>
48 #include <machine/md_var.h>
49 
50 #include <dev/iicbus/iicbus.h>
51 #include <dev/iicbus/iiconf.h>
52 #include <dev/led/led.h>
53 #include <dev/ofw/openfirm.h>
54 #include <dev/ofw/ofw_bus.h>
55 #include <dev/ofw/ofw_bus_subr.h>
56 #include <powerpc/powermac/macgpiovar.h>
57 
58 #include "clock_if.h"
59 #include "iicbus_if.h"
60 
61 struct smu_cmd {
62 	volatile uint8_t cmd;
63 	uint8_t		len;
64 	uint8_t		data[254];
65 
66 	STAILQ_ENTRY(smu_cmd) cmd_q;
67 };
68 
69 STAILQ_HEAD(smu_cmdq, smu_cmd);
70 
71 struct smu_fan {
72 	cell_t	reg;
73 	cell_t	min_rpm;
74 	cell_t	max_rpm;
75 	cell_t	unmanaged_rpm;
76 	char	location[32];
77 
78 	int	old_style;
79 	int	setpoint;
80 };
81 
82 struct smu_sensor {
83 	cell_t	reg;
84 	char	location[32];
85 	enum {
86 		SMU_CURRENT_SENSOR,
87 		SMU_VOLTAGE_SENSOR,
88 		SMU_POWER_SENSOR,
89 		SMU_TEMP_SENSOR
90 	} type;
91 };
92 
93 struct smu_softc {
94 	device_t	sc_dev;
95 	struct mtx	sc_mtx;
96 
97 	struct resource	*sc_memr;
98 	int		sc_memrid;
99 	int		sc_u3;
100 
101 	bus_dma_tag_t	sc_dmatag;
102 	bus_space_tag_t	sc_bt;
103 	bus_space_handle_t sc_mailbox;
104 
105 	struct smu_cmd	*sc_cmd, *sc_cur_cmd;
106 	bus_addr_t	sc_cmd_phys;
107 	bus_dmamap_t	sc_cmd_dmamap;
108 	struct smu_cmdq	sc_cmdq;
109 
110 	struct smu_fan	*sc_fans;
111 	int		sc_nfans;
112 	struct smu_sensor *sc_sensors;
113 	int		sc_nsensors;
114 
115 	int		sc_doorbellirqid;
116 	struct resource	*sc_doorbellirq;
117 	void		*sc_doorbellirqcookie;
118 
119 	struct proc	*sc_fanmgt_proc;
120 	time_t		sc_lastuserchange;
121 
122 	/* Calibration data */
123 	uint16_t	sc_cpu_diode_scale;
124 	int16_t		sc_cpu_diode_offset;
125 
126 	uint16_t	sc_cpu_volt_scale;
127 	int16_t		sc_cpu_volt_offset;
128 	uint16_t	sc_cpu_curr_scale;
129 	int16_t		sc_cpu_curr_offset;
130 
131 	uint16_t	sc_slots_pow_scale;
132 	int16_t		sc_slots_pow_offset;
133 
134 	/* Thermal management parameters */
135 	int		sc_target_temp;		/* Default 55 C */
136 	int		sc_critical_temp;	/* Default 90 C */
137 
138 	struct cdev 	*sc_leddev;
139 };
140 
141 /* regular bus attachment functions */
142 
143 static int	smu_probe(device_t);
144 static int	smu_attach(device_t);
145 static const struct ofw_bus_devinfo *
146     smu_get_devinfo(device_t bus, device_t dev);
147 
148 /* cpufreq notification hooks */
149 
150 static void	smu_cpufreq_pre_change(device_t, const struct cf_level *level);
151 static void	smu_cpufreq_post_change(device_t, const struct cf_level *level);
152 
153 /* clock interface */
154 static int	smu_gettime(device_t dev, struct timespec *ts);
155 static int	smu_settime(device_t dev, struct timespec *ts);
156 
157 /* utility functions */
158 static int	smu_run_cmd(device_t dev, struct smu_cmd *cmd, int wait);
159 static int	smu_get_datablock(device_t dev, int8_t id, uint8_t *buf,
160 		    size_t len);
161 static void	smu_attach_i2c(device_t dev, phandle_t i2croot);
162 static void	smu_attach_fans(device_t dev, phandle_t fanroot);
163 static void	smu_attach_sensors(device_t dev, phandle_t sensroot);
164 static void	smu_fan_management_proc(void *xdev);
165 static void	smu_manage_fans(device_t smu);
166 static void	smu_set_sleepled(void *xdev, int onoff);
167 static int	smu_server_mode(SYSCTL_HANDLER_ARGS);
168 static void	smu_doorbell_intr(void *xdev);
169 static void	smu_shutdown(void *xdev, int howto);
170 
171 /* where to find the doorbell GPIO */
172 
173 static device_t	smu_doorbell = NULL;
174 
175 static device_method_t  smu_methods[] = {
176 	/* Device interface */
177 	DEVMETHOD(device_probe,		smu_probe),
178 	DEVMETHOD(device_attach,	smu_attach),
179 
180 	/* Clock interface */
181 	DEVMETHOD(clock_gettime,	smu_gettime),
182 	DEVMETHOD(clock_settime,	smu_settime),
183 
184 	/* ofw_bus interface */
185 	DEVMETHOD(bus_child_pnpinfo_str,ofw_bus_gen_child_pnpinfo_str),
186 	DEVMETHOD(ofw_bus_get_devinfo,	smu_get_devinfo),
187 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
188 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
189 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
190 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
191 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
192 
193 	{ 0, 0 },
194 };
195 
196 static driver_t smu_driver = {
197 	"smu",
198 	smu_methods,
199 	sizeof(struct smu_softc)
200 };
201 
202 static devclass_t smu_devclass;
203 
204 DRIVER_MODULE(smu, nexus, smu_driver, smu_devclass, 0, 0);
205 MALLOC_DEFINE(M_SMU, "smu", "SMU Sensor Information");
206 
207 #define SMU_MAILBOX		0x8000860c
208 #define SMU_FANMGT_INTERVAL	1000 /* ms */
209 
210 /* Command types */
211 #define SMU_ADC			0xd8
212 #define SMU_FAN			0x4a
213 #define SMU_I2C			0x9a
214 #define  SMU_I2C_SIMPLE		0x00
215 #define  SMU_I2C_NORMAL		0x01
216 #define  SMU_I2C_COMBINED	0x02
217 #define SMU_MISC		0xee
218 #define  SMU_MISC_GET_DATA	0x02
219 #define  SMU_MISC_LED_CTRL	0x04
220 #define SMU_POWER		0xaa
221 #define SMU_POWER_EVENTS	0x8f
222 #define  SMU_PWR_GET_POWERUP	0x00
223 #define  SMU_PWR_SET_POWERUP	0x01
224 #define  SMU_PWR_CLR_POWERUP	0x02
225 #define SMU_RTC			0x8e
226 #define  SMU_RTC_GET		0x81
227 #define  SMU_RTC_SET		0x80
228 
229 /* Power event types */
230 #define SMU_WAKEUP_KEYPRESS	0x01
231 #define SMU_WAKEUP_AC_INSERT	0x02
232 #define SMU_WAKEUP_AC_CHANGE	0x04
233 #define SMU_WAKEUP_RING		0x10
234 
235 /* Data blocks */
236 #define SMU_CPUTEMP_CAL		0x18
237 #define SMU_CPUVOLT_CAL		0x21
238 #define SMU_SLOTPW_CAL		0x78
239 
240 /* Partitions */
241 #define SMU_PARTITION		0x3e
242 #define SMU_PARTITION_LATEST	0x01
243 #define SMU_PARTITION_BASE	0x02
244 #define SMU_PARTITION_UPDATE	0x03
245 
246 static int
247 smu_probe(device_t dev)
248 {
249 	const char *name = ofw_bus_get_name(dev);
250 
251 	if (strcmp(name, "smu") != 0)
252 		return (ENXIO);
253 
254 	device_set_desc(dev, "Apple System Management Unit");
255 	return (0);
256 }
257 
258 static void
259 smu_phys_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
260 {
261 	struct smu_softc *sc = xsc;
262 
263 	sc->sc_cmd_phys = segs[0].ds_addr;
264 }
265 
266 static int
267 smu_attach(device_t dev)
268 {
269 	struct smu_softc *sc;
270 	phandle_t	node, child;
271 	uint8_t		data[12];
272 
273 	sc = device_get_softc(dev);
274 
275 	mtx_init(&sc->sc_mtx, "smu", NULL, MTX_DEF);
276 	sc->sc_cur_cmd = NULL;
277 	sc->sc_doorbellirqid = -1;
278 
279 	sc->sc_u3 = 0;
280 	if (OF_finddevice("/u3") != -1)
281 		sc->sc_u3 = 1;
282 
283 	/*
284 	 * Map the mailbox area. This should be determined from firmware,
285 	 * but I have not found a simple way to do that.
286 	 */
287 	bus_dma_tag_create(NULL, 16, 0, BUS_SPACE_MAXADDR_32BIT,
288 	    BUS_SPACE_MAXADDR, NULL, NULL, PAGE_SIZE, 1, PAGE_SIZE, 0, NULL,
289 	    NULL, &(sc->sc_dmatag));
290 	sc->sc_bt = &bs_le_tag;
291 	bus_space_map(sc->sc_bt, SMU_MAILBOX, 4, 0, &sc->sc_mailbox);
292 
293 	/*
294 	 * Allocate the command buffer. This can be anywhere in the low 4 GB
295 	 * of memory.
296 	 */
297 	bus_dmamem_alloc(sc->sc_dmatag, (void **)&sc->sc_cmd, BUS_DMA_WAITOK |
298 	    BUS_DMA_ZERO, &sc->sc_cmd_dmamap);
299 	bus_dmamap_load(sc->sc_dmatag, sc->sc_cmd_dmamap,
300 	    sc->sc_cmd, PAGE_SIZE, smu_phys_callback, sc, 0);
301 	STAILQ_INIT(&sc->sc_cmdq);
302 
303 	/*
304 	 * Set up handlers to change CPU voltage when CPU frequency is changed.
305 	 */
306 	EVENTHANDLER_REGISTER(cpufreq_pre_change, smu_cpufreq_pre_change, dev,
307 	    EVENTHANDLER_PRI_ANY);
308 	EVENTHANDLER_REGISTER(cpufreq_post_change, smu_cpufreq_post_change, dev,
309 	    EVENTHANDLER_PRI_ANY);
310 
311 	/*
312 	 * Detect and attach child devices.
313 	 */
314 	node = ofw_bus_get_node(dev);
315 	for (child = OF_child(node); child != 0; child = OF_peer(child)) {
316 		char name[32];
317 		memset(name, 0, sizeof(name));
318 		OF_getprop(child, "name", name, sizeof(name));
319 
320 		if (strncmp(name, "rpm-fans", 9) == 0 ||
321 		    strncmp(name, "fans", 5) == 0)
322 			smu_attach_fans(dev, child);
323 
324 		if (strncmp(name, "sensors", 8) == 0)
325 			smu_attach_sensors(dev, child);
326 
327 		if (strncmp(name, "smu-i2c-control", 15) == 0)
328 			smu_attach_i2c(dev, child);
329 	}
330 
331 	/* Some SMUs have the I2C children directly under the bus. */
332 	smu_attach_i2c(dev, node);
333 
334 	/*
335 	 * Collect calibration constants.
336 	 */
337 	smu_get_datablock(dev, SMU_CPUTEMP_CAL, data, sizeof(data));
338 	sc->sc_cpu_diode_scale = (data[4] << 8) + data[5];
339 	sc->sc_cpu_diode_offset = (data[6] << 8) + data[7];
340 
341 	smu_get_datablock(dev, SMU_CPUVOLT_CAL, data, sizeof(data));
342 	sc->sc_cpu_volt_scale = (data[4] << 8) + data[5];
343 	sc->sc_cpu_volt_offset = (data[6] << 8) + data[7];
344 	sc->sc_cpu_curr_scale = (data[8] << 8) + data[9];
345 	sc->sc_cpu_curr_offset = (data[10] << 8) + data[11];
346 
347 	smu_get_datablock(dev, SMU_SLOTPW_CAL, data, sizeof(data));
348 	sc->sc_slots_pow_scale = (data[4] << 8) + data[5];
349 	sc->sc_slots_pow_offset = (data[6] << 8) + data[7];
350 
351 	/*
352 	 * Set up simple-minded thermal management.
353 	 */
354 	sc->sc_target_temp = 55;
355 	sc->sc_critical_temp = 90;
356 
357 	SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
358 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
359 	    "target_temp", CTLTYPE_INT | CTLFLAG_RW, &sc->sc_target_temp,
360 	    sizeof(int), "Target temperature (C)");
361 	SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
362 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
363 	    "critical_temp", CTLTYPE_INT | CTLFLAG_RW,
364 	    &sc->sc_critical_temp, sizeof(int), "Critical temperature (C)");
365 
366 	kproc_create(smu_fan_management_proc, dev, &sc->sc_fanmgt_proc,
367 	    RFHIGHPID, 0, "smu_thermal");
368 
369 	/*
370 	 * Set up LED interface
371 	 */
372 	sc->sc_leddev = led_create(smu_set_sleepled, dev, "sleepled");
373 
374 	/*
375 	 * Reset on power loss behavior
376 	 */
377 
378 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
379             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
380 	    "server_mode", CTLTYPE_INT | CTLFLAG_RW, dev, 0,
381 	    smu_server_mode, "I", "Enable reboot after power failure");
382 
383 	/*
384 	 * Set up doorbell interrupt.
385 	 */
386 	sc->sc_doorbellirqid = 0;
387 	sc->sc_doorbellirq = bus_alloc_resource_any(smu_doorbell, SYS_RES_IRQ,
388 	    &sc->sc_doorbellirqid, RF_ACTIVE);
389 	bus_setup_intr(smu_doorbell, sc->sc_doorbellirq,
390 	    INTR_TYPE_MISC | INTR_MPSAFE, NULL, smu_doorbell_intr, dev,
391 	    &sc->sc_doorbellirqcookie);
392 	powerpc_config_intr(rman_get_start(sc->sc_doorbellirq),
393 	    INTR_TRIGGER_EDGE, INTR_POLARITY_LOW);
394 
395 	/*
396 	 * Connect RTC interface.
397 	 */
398 	clock_register(dev, 1000);
399 
400 	/*
401 	 * Learn about shutdown events
402 	 */
403 	EVENTHANDLER_REGISTER(shutdown_final, smu_shutdown, dev,
404 	    SHUTDOWN_PRI_LAST);
405 
406 	return (bus_generic_attach(dev));
407 }
408 
409 static const struct ofw_bus_devinfo *
410 smu_get_devinfo(device_t bus, device_t dev)
411 {
412 
413 	return (device_get_ivars(dev));
414 }
415 
416 static void
417 smu_send_cmd(device_t dev, struct smu_cmd *cmd)
418 {
419 	struct smu_softc *sc;
420 
421 	sc = device_get_softc(dev);
422 
423 	mtx_assert(&sc->sc_mtx, MA_OWNED);
424 
425 	if (sc->sc_u3)
426 		powerpc_pow_enabled = 0; /* SMU cannot work if we go to NAP */
427 
428 	sc->sc_cur_cmd = cmd;
429 
430 	/* Copy the command to the mailbox */
431 	sc->sc_cmd->cmd = cmd->cmd;
432 	sc->sc_cmd->len = cmd->len;
433 	memcpy(sc->sc_cmd->data, cmd->data, sizeof(cmd->data));
434 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cmd_dmamap, BUS_DMASYNC_PREWRITE);
435 	bus_space_write_4(sc->sc_bt, sc->sc_mailbox, 0, sc->sc_cmd_phys);
436 
437 	/* Flush the cacheline it is in -- SMU bypasses the cache */
438 	__asm __volatile("sync; dcbf 0,%0; sync" :: "r"(sc->sc_cmd): "memory");
439 
440 	/* Ring SMU doorbell */
441 	macgpio_write(smu_doorbell, GPIO_DDR_OUTPUT);
442 }
443 
444 static void
445 smu_doorbell_intr(void *xdev)
446 {
447 	device_t smu;
448 	struct smu_softc *sc;
449 	int doorbell_ack;
450 
451 	smu = xdev;
452 	doorbell_ack = macgpio_read(smu_doorbell);
453 	sc = device_get_softc(smu);
454 
455 	if (doorbell_ack != (GPIO_DDR_OUTPUT | GPIO_LEVEL_RO | GPIO_DATA))
456 		return;
457 
458 	mtx_lock(&sc->sc_mtx);
459 
460 	if (sc->sc_cur_cmd == NULL)	/* spurious */
461 		goto done;
462 
463 	/* Check result. First invalidate the cache again... */
464 	__asm __volatile("dcbf 0,%0; sync" :: "r"(sc->sc_cmd) : "memory");
465 
466 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cmd_dmamap, BUS_DMASYNC_POSTREAD);
467 
468 	sc->sc_cur_cmd->cmd = sc->sc_cmd->cmd;
469 	sc->sc_cur_cmd->len = sc->sc_cmd->len;
470 	memcpy(sc->sc_cur_cmd->data, sc->sc_cmd->data,
471 	    sizeof(sc->sc_cmd->data));
472 	wakeup(sc->sc_cur_cmd);
473 	sc->sc_cur_cmd = NULL;
474 	if (sc->sc_u3)
475 		powerpc_pow_enabled = 1;
476 
477     done:
478 	/* Queue next command if one is pending */
479 	if (STAILQ_FIRST(&sc->sc_cmdq) != NULL) {
480 		sc->sc_cur_cmd = STAILQ_FIRST(&sc->sc_cmdq);
481 		STAILQ_REMOVE_HEAD(&sc->sc_cmdq, cmd_q);
482 		smu_send_cmd(smu, sc->sc_cur_cmd);
483 	}
484 
485 	mtx_unlock(&sc->sc_mtx);
486 }
487 
488 static int
489 smu_run_cmd(device_t dev, struct smu_cmd *cmd, int wait)
490 {
491 	struct smu_softc *sc;
492 	uint8_t cmd_code;
493 	int error;
494 
495 	sc = device_get_softc(dev);
496 	cmd_code = cmd->cmd;
497 
498 	mtx_lock(&sc->sc_mtx);
499 	if (sc->sc_cur_cmd != NULL) {
500 		STAILQ_INSERT_TAIL(&sc->sc_cmdq, cmd, cmd_q);
501 	} else
502 		smu_send_cmd(dev, cmd);
503 	mtx_unlock(&sc->sc_mtx);
504 
505 	if (!wait)
506 		return (0);
507 
508 	if (sc->sc_doorbellirqid < 0) {
509 		/* Poll if the IRQ has not been set up yet */
510 		do {
511 			DELAY(50);
512 			smu_doorbell_intr(dev);
513 		} while (sc->sc_cur_cmd != NULL);
514 	} else {
515 		/* smu_doorbell_intr will wake us when the command is ACK'ed */
516 		error = tsleep(cmd, 0, "smu", 800 * hz / 1000);
517 		if (error != 0)
518 			smu_doorbell_intr(dev);	/* One last chance */
519 
520 		if (error != 0) {
521 		    mtx_lock(&sc->sc_mtx);
522 		    if (cmd->cmd == cmd_code) {	/* Never processed */
523 			/* Abort this command if we timed out */
524 			if (sc->sc_cur_cmd == cmd)
525 				sc->sc_cur_cmd = NULL;
526 			else
527 				STAILQ_REMOVE(&sc->sc_cmdq, cmd, smu_cmd,
528 				    cmd_q);
529 			mtx_unlock(&sc->sc_mtx);
530 			return (error);
531 		    }
532 		    error = 0;
533 		    mtx_unlock(&sc->sc_mtx);
534 		}
535 	}
536 
537 	/* SMU acks the command by inverting the command bits */
538 	if (cmd->cmd == ((~cmd_code) & 0xff))
539 		error = 0;
540 	else
541 		error = EIO;
542 
543 	return (error);
544 }
545 
546 static int
547 smu_get_datablock(device_t dev, int8_t id, uint8_t *buf, size_t len)
548 {
549 	struct smu_cmd cmd;
550 	uint8_t addr[4];
551 
552 	cmd.cmd = SMU_PARTITION;
553 	cmd.len = 2;
554 	cmd.data[0] = SMU_PARTITION_LATEST;
555 	cmd.data[1] = id;
556 
557 	smu_run_cmd(dev, &cmd, 1);
558 
559 	addr[0] = addr[1] = 0;
560 	addr[2] = cmd.data[0];
561 	addr[3] = cmd.data[1];
562 
563 	cmd.cmd = SMU_MISC;
564 	cmd.len = 7;
565 	cmd.data[0] = SMU_MISC_GET_DATA;
566 	cmd.data[1] = sizeof(addr);
567 	memcpy(&cmd.data[2], addr, sizeof(addr));
568 	cmd.data[6] = len;
569 
570 	smu_run_cmd(dev, &cmd, 1);
571 	memcpy(buf, cmd.data, len);
572 	return (0);
573 }
574 
575 static void
576 smu_slew_cpu_voltage(device_t dev, int to)
577 {
578 	struct smu_cmd cmd;
579 
580 	cmd.cmd = SMU_POWER;
581 	cmd.len = 8;
582 	cmd.data[0] = 'V';
583 	cmd.data[1] = 'S';
584 	cmd.data[2] = 'L';
585 	cmd.data[3] = 'E';
586 	cmd.data[4] = 'W';
587 	cmd.data[5] = 0xff;
588 	cmd.data[6] = 1;
589 	cmd.data[7] = to;
590 
591 	smu_run_cmd(dev, &cmd, 1);
592 }
593 
594 static void
595 smu_cpufreq_pre_change(device_t dev, const struct cf_level *level)
596 {
597 	/*
598 	 * Make sure the CPU voltage is raised before we raise
599 	 * the clock.
600 	 */
601 
602 	if (level->rel_set[0].freq == 10000 /* max */)
603 		smu_slew_cpu_voltage(dev, 0);
604 }
605 
606 static void
607 smu_cpufreq_post_change(device_t dev, const struct cf_level *level)
608 {
609 	/* We are safe to reduce CPU voltage after a downward transition */
610 
611 	if (level->rel_set[0].freq < 10000 /* max */)
612 		smu_slew_cpu_voltage(dev, 1); /* XXX: 1/4 voltage for 970MP? */
613 }
614 
615 /* Routines for probing the SMU doorbell GPIO */
616 static int doorbell_probe(device_t dev);
617 static int doorbell_attach(device_t dev);
618 
619 static device_method_t  doorbell_methods[] = {
620 	/* Device interface */
621 	DEVMETHOD(device_probe,		doorbell_probe),
622 	DEVMETHOD(device_attach,	doorbell_attach),
623 	{ 0, 0 },
624 };
625 
626 static driver_t doorbell_driver = {
627 	"smudoorbell",
628 	doorbell_methods,
629 	0
630 };
631 
632 static devclass_t doorbell_devclass;
633 
634 DRIVER_MODULE(smudoorbell, macgpio, doorbell_driver, doorbell_devclass, 0, 0);
635 
636 static int
637 doorbell_probe(device_t dev)
638 {
639 	const char *name = ofw_bus_get_name(dev);
640 
641 	if (strcmp(name, "smu-doorbell") != 0)
642 		return (ENXIO);
643 
644 	device_set_desc(dev, "SMU Doorbell GPIO");
645 	device_quiet(dev);
646 	return (0);
647 }
648 
649 static int
650 doorbell_attach(device_t dev)
651 {
652 	smu_doorbell = dev;
653 	return (0);
654 }
655 
656 /*
657  * Sensor and fan management
658  */
659 
660 static int
661 smu_fan_set_rpm(device_t smu, struct smu_fan *fan, int rpm)
662 {
663 	struct smu_cmd cmd;
664 	int error;
665 
666 	cmd.cmd = SMU_FAN;
667 	error = EIO;
668 
669 	/* Clamp to allowed range */
670 	rpm = max(fan->min_rpm, rpm);
671 	rpm = min(fan->max_rpm, rpm);
672 
673 	/*
674 	 * Apple has two fan control mechanisms. We can't distinguish
675 	 * them except by seeing if the new one fails. If the new one
676 	 * fails, use the old one.
677 	 */
678 
679 	if (!fan->old_style) {
680 		cmd.len = 4;
681 		cmd.data[0] = 0x30;
682 		cmd.data[1] = fan->reg;
683 		cmd.data[2] = (rpm >> 8) & 0xff;
684 		cmd.data[3] = rpm & 0xff;
685 
686 		error = smu_run_cmd(smu, &cmd, 1);
687 		if (error)
688 			fan->old_style = 1;
689 	}
690 
691 	if (fan->old_style) {
692 		cmd.len = 14;
693 		cmd.data[0] = 0;
694 		cmd.data[1] = 1 << fan->reg;
695 		cmd.data[2 + 2*fan->reg] = (rpm >> 8) & 0xff;
696 		cmd.data[3 + 2*fan->reg] = rpm & 0xff;
697 		error = smu_run_cmd(smu, &cmd, 1);
698 	}
699 
700 	if (error == 0)
701 		fan->setpoint = rpm;
702 
703 	return (error);
704 }
705 
706 static int
707 smu_fan_read_rpm(device_t smu, struct smu_fan *fan)
708 {
709 	struct smu_cmd cmd;
710 	int rpm, error;
711 
712 	if (!fan->old_style) {
713 		cmd.cmd = SMU_FAN;
714 		cmd.len = 2;
715 		cmd.data[0] = 0x31;
716 		cmd.data[1] = fan->reg;
717 
718 		error = smu_run_cmd(smu, &cmd, 1);
719 		if (error)
720 			fan->old_style = 1;
721 
722 		rpm = (cmd.data[0] << 8) | cmd.data[1];
723 	}
724 
725 	if (fan->old_style) {
726 		cmd.cmd = SMU_FAN;
727 		cmd.len = 1;
728 		cmd.data[0] = 1;
729 
730 		error = smu_run_cmd(smu, &cmd, 1);
731 		if (error)
732 			return (error);
733 
734 		rpm = (cmd.data[fan->reg*2+1] << 8) | cmd.data[fan->reg*2+2];
735 	}
736 
737 	return (rpm);
738 }
739 
740 static int
741 smu_fanrpm_sysctl(SYSCTL_HANDLER_ARGS)
742 {
743 	device_t smu;
744 	struct smu_softc *sc;
745 	struct smu_fan *fan;
746 	int rpm, error;
747 
748 	smu = arg1;
749 	sc = device_get_softc(smu);
750 	fan = &sc->sc_fans[arg2];
751 
752 	rpm = smu_fan_read_rpm(smu, fan);
753 	if (rpm < 0)
754 		return (rpm);
755 
756 	error = sysctl_handle_int(oidp, &rpm, 0, req);
757 
758 	if (error || !req->newptr)
759 		return (error);
760 
761 	sc->sc_lastuserchange = time_uptime;
762 
763 	return (smu_fan_set_rpm(smu, fan, rpm));
764 }
765 
766 static void
767 smu_attach_fans(device_t dev, phandle_t fanroot)
768 {
769 	struct smu_fan *fan;
770 	struct smu_softc *sc;
771 	struct sysctl_oid *oid, *fanroot_oid;
772 	struct sysctl_ctx_list *ctx;
773 	phandle_t child;
774 	char type[32], sysctl_name[32];
775 	int i;
776 
777 	sc = device_get_softc(dev);
778 	sc->sc_nfans = 0;
779 
780 	for (child = OF_child(fanroot); child != 0; child = OF_peer(child))
781 		sc->sc_nfans++;
782 
783 	if (sc->sc_nfans == 0) {
784 		device_printf(dev, "WARNING: No fans detected!\n");
785 		return;
786 	}
787 
788 	sc->sc_fans = malloc(sc->sc_nfans * sizeof(struct smu_fan), M_SMU,
789 	    M_WAITOK | M_ZERO);
790 
791 	fan = sc->sc_fans;
792 	sc->sc_nfans = 0;
793 
794 	ctx = device_get_sysctl_ctx(dev);
795 	fanroot_oid = SYSCTL_ADD_NODE(ctx,
796 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "fans",
797 	    CTLFLAG_RD, 0, "SMU Fan Information");
798 
799 	for (child = OF_child(fanroot); child != 0; child = OF_peer(child)) {
800 		OF_getprop(child, "device_type", type, sizeof(type));
801 		if (strcmp(type, "fan-rpm-control") != 0)
802 			continue;
803 
804 		fan->old_style = 0;
805 		OF_getprop(child, "reg", &fan->reg, sizeof(cell_t));
806 		OF_getprop(child, "min-value", &fan->min_rpm, sizeof(cell_t));
807 		OF_getprop(child, "max-value", &fan->max_rpm, sizeof(cell_t));
808 
809 		if (OF_getprop(child, "unmanaged-value", &fan->unmanaged_rpm,
810 		    sizeof(cell_t)) != sizeof(cell_t))
811 			fan->unmanaged_rpm = fan->max_rpm;
812 
813 		fan->setpoint = smu_fan_read_rpm(dev, fan);
814 
815 		OF_getprop(child, "location", fan->location,
816 		    sizeof(fan->location));
817 
818 		/* Add sysctls */
819 		for (i = 0; i < strlen(fan->location); i++) {
820 			sysctl_name[i] = tolower(fan->location[i]);
821 			if (isspace(sysctl_name[i]))
822 				sysctl_name[i] = '_';
823 		}
824 		sysctl_name[i] = 0;
825 
826 		oid = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(fanroot_oid),
827 		    OID_AUTO, sysctl_name, CTLFLAG_RD, 0, "Fan Information");
828 		SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "minrpm",
829 		    CTLTYPE_INT | CTLFLAG_RD, &fan->min_rpm, sizeof(cell_t),
830 		    "Minimum allowed RPM");
831 		SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "maxrpm",
832 		    CTLTYPE_INT | CTLFLAG_RD, &fan->max_rpm, sizeof(cell_t),
833 		    "Maximum allowed RPM");
834 		SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "rpm",
835 		    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, dev,
836 		    sc->sc_nfans, smu_fanrpm_sysctl, "I", "Fan RPM");
837 
838 		fan++;
839 		sc->sc_nfans++;
840 	}
841 }
842 
843 static int
844 smu_sensor_read(device_t smu, struct smu_sensor *sens, int *val)
845 {
846 	struct smu_cmd cmd;
847 	struct smu_softc *sc;
848 	int64_t value;
849 	int error;
850 
851 	cmd.cmd = SMU_ADC;
852 	cmd.len = 1;
853 	cmd.data[0] = sens->reg;
854 	error = 0;
855 
856 	error = smu_run_cmd(smu, &cmd, 1);
857 	if (error != 0)
858 		return (error);
859 
860 	sc = device_get_softc(smu);
861 	value = (cmd.data[0] << 8) | cmd.data[1];
862 
863 	switch (sens->type) {
864 	case SMU_TEMP_SENSOR:
865 		value *= sc->sc_cpu_diode_scale;
866 		value >>= 3;
867 		value += ((int64_t)sc->sc_cpu_diode_offset) << 9;
868 		value <<= 1;
869 
870 		/* Convert from 16.16 fixed point degC into integer C. */
871 		value >>= 16;
872 		break;
873 	case SMU_VOLTAGE_SENSOR:
874 		value *= sc->sc_cpu_volt_scale;
875 		value += sc->sc_cpu_volt_offset;
876 		value <<= 4;
877 
878 		/* Convert from 16.16 fixed point V into mV. */
879 		value *= 15625;
880 		value /= 1024;
881 		value /= 1000;
882 		break;
883 	case SMU_CURRENT_SENSOR:
884 		value *= sc->sc_cpu_curr_scale;
885 		value += sc->sc_cpu_curr_offset;
886 		value <<= 4;
887 
888 		/* Convert from 16.16 fixed point A into mA. */
889 		value *= 15625;
890 		value /= 1024;
891 		value /= 1000;
892 		break;
893 	case SMU_POWER_SENSOR:
894 		value *= sc->sc_slots_pow_scale;
895 		value += sc->sc_slots_pow_offset;
896 		value <<= 4;
897 
898 		/* Convert from 16.16 fixed point W into mW. */
899 		value *= 15625;
900 		value /= 1024;
901 		value /= 1000;
902 		break;
903 	}
904 
905 	*val = value;
906 	return (0);
907 }
908 
909 static int
910 smu_sensor_sysctl(SYSCTL_HANDLER_ARGS)
911 {
912 	device_t smu;
913 	struct smu_softc *sc;
914 	struct smu_sensor *sens;
915 	int value, error;
916 
917 	smu = arg1;
918 	sc = device_get_softc(smu);
919 	sens = &sc->sc_sensors[arg2];
920 
921 	error = smu_sensor_read(smu, sens, &value);
922 	if (error != 0)
923 		return (error);
924 
925 	error = sysctl_handle_int(oidp, &value, 0, req);
926 
927 	return (error);
928 }
929 
930 static void
931 smu_attach_sensors(device_t dev, phandle_t sensroot)
932 {
933 	struct smu_sensor *sens;
934 	struct smu_softc *sc;
935 	struct sysctl_oid *sensroot_oid;
936 	struct sysctl_ctx_list *ctx;
937 	phandle_t child;
938 	char type[32];
939 	int i;
940 
941 	sc = device_get_softc(dev);
942 	sc->sc_nsensors = 0;
943 
944 	for (child = OF_child(sensroot); child != 0; child = OF_peer(child))
945 		sc->sc_nsensors++;
946 
947 	if (sc->sc_nsensors == 0) {
948 		device_printf(dev, "WARNING: No sensors detected!\n");
949 		return;
950 	}
951 
952 	sc->sc_sensors = malloc(sc->sc_nsensors * sizeof(struct smu_sensor),
953 	    M_SMU, M_WAITOK | M_ZERO);
954 
955 	sens = sc->sc_sensors;
956 	sc->sc_nsensors = 0;
957 
958 	ctx = device_get_sysctl_ctx(dev);
959 	sensroot_oid = SYSCTL_ADD_NODE(ctx,
960 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "sensors",
961 	    CTLFLAG_RD, 0, "SMU Sensor Information");
962 
963 	for (child = OF_child(sensroot); child != 0; child = OF_peer(child)) {
964 		char sysctl_name[40], sysctl_desc[40];
965 		const char *units;
966 
967 		OF_getprop(child, "device_type", type, sizeof(type));
968 
969 		if (strcmp(type, "current-sensor") == 0) {
970 			sens->type = SMU_CURRENT_SENSOR;
971 			units = "mA";
972 		} else if (strcmp(type, "temp-sensor") == 0) {
973 			sens->type = SMU_TEMP_SENSOR;
974 			units = "C";
975 		} else if (strcmp(type, "voltage-sensor") == 0) {
976 			sens->type = SMU_VOLTAGE_SENSOR;
977 			units = "mV";
978 		} else if (strcmp(type, "power-sensor") == 0) {
979 			sens->type = SMU_POWER_SENSOR;
980 			units = "mW";
981 		} else {
982 			continue;
983 		}
984 
985 		OF_getprop(child, "reg", &sens->reg, sizeof(cell_t));
986 		OF_getprop(child, "location", sens->location,
987 		    sizeof(sens->location));
988 
989 		for (i = 0; i < strlen(sens->location); i++) {
990 			sysctl_name[i] = tolower(sens->location[i]);
991 			if (isspace(sysctl_name[i]))
992 				sysctl_name[i] = '_';
993 		}
994 		sysctl_name[i] = 0;
995 
996 		sprintf(sysctl_desc,"%s (%s)", sens->location, units);
997 
998 		SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(sensroot_oid), OID_AUTO,
999 		    sysctl_name, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
1000 		    dev, sc->sc_nsensors, smu_sensor_sysctl, "I", sysctl_desc);
1001 
1002 		sens++;
1003 		sc->sc_nsensors++;
1004 	}
1005 }
1006 
1007 static void
1008 smu_fan_management_proc(void *xdev)
1009 {
1010 	device_t smu = xdev;
1011 
1012 	while(1) {
1013 		smu_manage_fans(smu);
1014 		pause("smu", SMU_FANMGT_INTERVAL * hz / 1000);
1015 	}
1016 }
1017 
1018 static void
1019 smu_manage_fans(device_t smu)
1020 {
1021 	struct smu_softc *sc;
1022 	int i, maxtemp, temp, factor, error;
1023 
1024 	sc = device_get_softc(smu);
1025 
1026 	maxtemp = 0;
1027 	for (i = 0; i < sc->sc_nsensors; i++) {
1028 		if (sc->sc_sensors[i].type != SMU_TEMP_SENSOR)
1029 			continue;
1030 
1031 		error = smu_sensor_read(smu, &sc->sc_sensors[i], &temp);
1032 		if (error == 0 && temp > maxtemp)
1033 			maxtemp = temp;
1034 	}
1035 
1036 	if (maxtemp > sc->sc_critical_temp) {
1037 		device_printf(smu, "WARNING: Current system temperature (%d C) "
1038 		    "exceeds critical temperature (%d C)! Shutting down!\n",
1039 		    maxtemp, sc->sc_critical_temp);
1040 		shutdown_nice(RB_POWEROFF);
1041 	}
1042 
1043 	if (maxtemp - sc->sc_target_temp > 20)
1044 		device_printf(smu, "WARNING: Current system temperature (%d C) "
1045 		    "more than 20 degrees over target temperature (%d C)!\n",
1046 		    maxtemp, sc->sc_target_temp);
1047 
1048 	if (time_uptime - sc->sc_lastuserchange < 3) {
1049 		/*
1050 		 * If we have heard from a user process in the last 3 seconds,
1051 		 * go away.
1052 		 */
1053 
1054 		return;
1055 	}
1056 
1057 	if (maxtemp < 10) { /* Bail if no good sensors */
1058 		for (i = 0; i < sc->sc_nfans; i++)
1059 			smu_fan_set_rpm(smu, &sc->sc_fans[i],
1060 			    sc->sc_fans[i].unmanaged_rpm);
1061 		return;
1062 	}
1063 
1064 	if (maxtemp - sc->sc_target_temp > 4)
1065 		factor = 110;
1066 	else if (maxtemp - sc->sc_target_temp > 1)
1067 		factor = 105;
1068 	else if (sc->sc_target_temp - maxtemp > 4)
1069 		factor = 90;
1070 	else if (sc->sc_target_temp - maxtemp > 1)
1071 		factor = 95;
1072 	else
1073 		factor = 100;
1074 
1075 	for (i = 0; i < sc->sc_nfans; i++)
1076 		smu_fan_set_rpm(smu, &sc->sc_fans[i],
1077 		    (sc->sc_fans[i].setpoint * factor) / 100);
1078 }
1079 
1080 static void
1081 smu_set_sleepled(void *xdev, int onoff)
1082 {
1083 	static struct smu_cmd cmd;
1084 	device_t smu = xdev;
1085 
1086 	cmd.cmd = SMU_MISC;
1087 	cmd.len = 3;
1088 	cmd.data[0] = SMU_MISC_LED_CTRL;
1089 	cmd.data[1] = 0;
1090 	cmd.data[2] = onoff;
1091 
1092 	smu_run_cmd(smu, &cmd, 0);
1093 }
1094 
1095 static int
1096 smu_server_mode(SYSCTL_HANDLER_ARGS)
1097 {
1098 	struct smu_cmd cmd;
1099 	u_int server_mode;
1100 	device_t smu = arg1;
1101 	int error;
1102 
1103 	cmd.cmd = SMU_POWER_EVENTS;
1104 	cmd.len = 1;
1105 	cmd.data[0] = SMU_PWR_GET_POWERUP;
1106 
1107 	error = smu_run_cmd(smu, &cmd, 1);
1108 
1109 	if (error)
1110 		return (error);
1111 
1112 	server_mode = (cmd.data[1] & SMU_WAKEUP_AC_INSERT) ? 1 : 0;
1113 
1114 	error = sysctl_handle_int(oidp, &server_mode, 0, req);
1115 
1116 	if (error || !req->newptr)
1117 		return (error);
1118 
1119 	if (server_mode == 1)
1120 		cmd.data[0] = SMU_PWR_SET_POWERUP;
1121 	else if (server_mode == 0)
1122 		cmd.data[0] = SMU_PWR_CLR_POWERUP;
1123 	else
1124 		return (EINVAL);
1125 
1126 	cmd.len = 3;
1127 	cmd.data[1] = 0;
1128 	cmd.data[2] = SMU_WAKEUP_AC_INSERT;
1129 
1130 	return (smu_run_cmd(smu, &cmd, 1));
1131 }
1132 
1133 static void
1134 smu_shutdown(void *xdev, int howto)
1135 {
1136 	device_t smu = xdev;
1137 	struct smu_cmd cmd;
1138 
1139 	cmd.cmd = SMU_POWER;
1140 	if (howto & RB_HALT)
1141 		strcpy(cmd.data, "SHUTDOWN");
1142 	else
1143 		strcpy(cmd.data, "RESTART");
1144 
1145 	cmd.len = strlen(cmd.data);
1146 
1147 	smu_run_cmd(smu, &cmd, 1);
1148 
1149 	for (;;);
1150 }
1151 
1152 static int
1153 smu_gettime(device_t dev, struct timespec *ts)
1154 {
1155 	struct smu_cmd cmd;
1156 	struct clocktime ct;
1157 
1158 	cmd.cmd = SMU_RTC;
1159 	cmd.len = 1;
1160 	cmd.data[0] = SMU_RTC_GET;
1161 
1162 	if (smu_run_cmd(dev, &cmd, 1) != 0)
1163 		return (ENXIO);
1164 
1165 	ct.nsec	= 0;
1166 	ct.sec	= bcd2bin(cmd.data[0]);
1167 	ct.min	= bcd2bin(cmd.data[1]);
1168 	ct.hour	= bcd2bin(cmd.data[2]);
1169 	ct.dow	= bcd2bin(cmd.data[3]);
1170 	ct.day	= bcd2bin(cmd.data[4]);
1171 	ct.mon	= bcd2bin(cmd.data[5]);
1172 	ct.year	= bcd2bin(cmd.data[6]) + 2000;
1173 
1174 	return (clock_ct_to_ts(&ct, ts));
1175 }
1176 
1177 static int
1178 smu_settime(device_t dev, struct timespec *ts)
1179 {
1180 	struct smu_cmd cmd;
1181 	struct clocktime ct;
1182 
1183 	cmd.cmd = SMU_RTC;
1184 	cmd.len = 8;
1185 	cmd.data[0] = SMU_RTC_SET;
1186 
1187 	clock_ts_to_ct(ts, &ct);
1188 
1189 	cmd.data[1] = bin2bcd(ct.sec);
1190 	cmd.data[2] = bin2bcd(ct.min);
1191 	cmd.data[3] = bin2bcd(ct.hour);
1192 	cmd.data[4] = bin2bcd(ct.dow);
1193 	cmd.data[5] = bin2bcd(ct.day);
1194 	cmd.data[6] = bin2bcd(ct.mon);
1195 	cmd.data[7] = bin2bcd(ct.year - 2000);
1196 
1197 	return (smu_run_cmd(dev, &cmd, 1));
1198 }
1199 
1200 /* SMU I2C Interface */
1201 
1202 static int smuiic_probe(device_t dev);
1203 static int smuiic_attach(device_t dev);
1204 static int smuiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs);
1205 static phandle_t smuiic_get_node(device_t bus, device_t dev);
1206 
1207 static device_method_t smuiic_methods[] = {
1208 	/* device interface */
1209 	DEVMETHOD(device_probe,         smuiic_probe),
1210 	DEVMETHOD(device_attach,        smuiic_attach),
1211 
1212 	/* iicbus interface */
1213 	DEVMETHOD(iicbus_callback,      iicbus_null_callback),
1214 	DEVMETHOD(iicbus_transfer,      smuiic_transfer),
1215 
1216 	/* ofw_bus interface */
1217 	DEVMETHOD(ofw_bus_get_node,     smuiic_get_node),
1218 
1219 	{ 0, 0 }
1220 };
1221 
1222 struct smuiic_softc {
1223 	struct mtx	sc_mtx;
1224 	volatile int	sc_iic_inuse;
1225 	int		sc_busno;
1226 };
1227 
1228 static driver_t smuiic_driver = {
1229 	"iichb",
1230 	smuiic_methods,
1231 	sizeof(struct smuiic_softc)
1232 };
1233 static devclass_t smuiic_devclass;
1234 
1235 DRIVER_MODULE(smuiic, smu, smuiic_driver, smuiic_devclass, 0, 0);
1236 
1237 static void
1238 smu_attach_i2c(device_t smu, phandle_t i2croot)
1239 {
1240 	phandle_t child;
1241 	device_t cdev;
1242 	struct ofw_bus_devinfo *dinfo;
1243 	char name[32];
1244 
1245 	for (child = OF_child(i2croot); child != 0; child = OF_peer(child)) {
1246 		if (OF_getprop(child, "name", name, sizeof(name)) <= 0)
1247 			continue;
1248 
1249 		if (strcmp(name, "i2c-bus") != 0 && strcmp(name, "i2c") != 0)
1250 			continue;
1251 
1252 		dinfo = malloc(sizeof(struct ofw_bus_devinfo), M_SMU,
1253 		    M_WAITOK | M_ZERO);
1254 		if (ofw_bus_gen_setup_devinfo(dinfo, child) != 0) {
1255 			free(dinfo, M_SMU);
1256 			continue;
1257 		}
1258 
1259 		cdev = device_add_child(smu, NULL, -1);
1260 		if (cdev == NULL) {
1261 			device_printf(smu, "<%s>: device_add_child failed\n",
1262 			    dinfo->obd_name);
1263 			ofw_bus_gen_destroy_devinfo(dinfo);
1264 			free(dinfo, M_SMU);
1265 			continue;
1266 		}
1267 		device_set_ivars(cdev, dinfo);
1268 	}
1269 }
1270 
1271 static int
1272 smuiic_probe(device_t dev)
1273 {
1274 	const char *name;
1275 
1276 	name = ofw_bus_get_name(dev);
1277 	if (name == NULL)
1278 		return (ENXIO);
1279 
1280 	if (strcmp(name, "i2c-bus") == 0 || strcmp(name, "i2c") == 0) {
1281 		device_set_desc(dev, "SMU I2C controller");
1282 		return (0);
1283 	}
1284 
1285 	return (ENXIO);
1286 }
1287 
1288 static int
1289 smuiic_attach(device_t dev)
1290 {
1291 	struct smuiic_softc *sc = device_get_softc(dev);
1292 	mtx_init(&sc->sc_mtx, "smuiic", NULL, MTX_DEF);
1293 	sc->sc_iic_inuse = 0;
1294 
1295 	/* Get our bus number */
1296 	OF_getprop(ofw_bus_get_node(dev), "reg", &sc->sc_busno,
1297 	    sizeof(sc->sc_busno));
1298 
1299 	/* Add the IIC bus layer */
1300 	device_add_child(dev, "iicbus", -1);
1301 
1302 	return (bus_generic_attach(dev));
1303 }
1304 
1305 static int
1306 smuiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
1307 {
1308 	struct smuiic_softc *sc = device_get_softc(dev);
1309 	struct smu_cmd cmd;
1310 	int i, j, error;
1311 
1312 	mtx_lock(&sc->sc_mtx);
1313 	while (sc->sc_iic_inuse)
1314 		mtx_sleep(sc, &sc->sc_mtx, 0, "smuiic", 100);
1315 
1316 	sc->sc_iic_inuse = 1;
1317 	error = 0;
1318 
1319 	for (i = 0; i < nmsgs; i++) {
1320 		cmd.cmd = SMU_I2C;
1321 		cmd.data[0] = sc->sc_busno;
1322 		if (msgs[i].flags & IIC_M_NOSTOP)
1323 			cmd.data[1] = SMU_I2C_COMBINED;
1324 		else
1325 			cmd.data[1] = SMU_I2C_SIMPLE;
1326 
1327 		cmd.data[2] = msgs[i].slave;
1328 		if (msgs[i].flags & IIC_M_RD)
1329 			cmd.data[2] |= 1;
1330 
1331 		if (msgs[i].flags & IIC_M_NOSTOP) {
1332 			KASSERT(msgs[i].len < 4,
1333 			    ("oversize I2C combined message"));
1334 
1335 			cmd.data[3] = min(msgs[i].len, 3);
1336 			memcpy(&cmd.data[4], msgs[i].buf, min(msgs[i].len, 3));
1337 			i++; /* Advance to next part of message */
1338 		} else {
1339 			cmd.data[3] = 0;
1340 			memset(&cmd.data[4], 0, 3);
1341 		}
1342 
1343 		cmd.data[7] = msgs[i].slave;
1344 		if (msgs[i].flags & IIC_M_RD)
1345 			cmd.data[7] |= 1;
1346 
1347 		cmd.data[8] = msgs[i].len;
1348 		if (msgs[i].flags & IIC_M_RD) {
1349 			memset(&cmd.data[9], 0xff, msgs[i].len);
1350 			cmd.len = 9;
1351 		} else {
1352 			memcpy(&cmd.data[9], msgs[i].buf, msgs[i].len);
1353 			cmd.len = 9 + msgs[i].len;
1354 		}
1355 
1356 		mtx_unlock(&sc->sc_mtx);
1357 		smu_run_cmd(device_get_parent(dev), &cmd, 1);
1358 		mtx_lock(&sc->sc_mtx);
1359 
1360 		for (j = 0; j < 10; j++) {
1361 			cmd.cmd = SMU_I2C;
1362 			cmd.len = 1;
1363 			cmd.data[0] = 0;
1364 			memset(&cmd.data[1], 0xff, msgs[i].len);
1365 
1366 			mtx_unlock(&sc->sc_mtx);
1367 			smu_run_cmd(device_get_parent(dev), &cmd, 1);
1368 			mtx_lock(&sc->sc_mtx);
1369 
1370 			if (!(cmd.data[0] & 0x80))
1371 				break;
1372 
1373 			mtx_sleep(sc, &sc->sc_mtx, 0, "smuiic", 10);
1374 		}
1375 
1376 		if (cmd.data[0] & 0x80) {
1377 			error = EIO;
1378 			msgs[i].len = 0;
1379 			goto exit;
1380 		}
1381 		memcpy(msgs[i].buf, &cmd.data[1], msgs[i].len);
1382 		msgs[i].len = cmd.len - 1;
1383 	}
1384 
1385     exit:
1386 	sc->sc_iic_inuse = 0;
1387 	mtx_unlock(&sc->sc_mtx);
1388 	wakeup(sc);
1389 	return (error);
1390 }
1391 
1392 static phandle_t
1393 smuiic_get_node(device_t bus, device_t dev)
1394 {
1395 
1396 	return (ofw_bus_get_node(bus));
1397 }
1398 
1399