xref: /dflybsd-src/sys/dev/disk/sili/sili_pm.c (revision b792147d2d9a225bb5c9a0d9ab69d4dbf010979e)
1 /*
2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "sili.h"
36 
37 static void sili_pm_dummy_done(struct ata_xfer *xa);
38 static void sili_pm_empty_done(struct sili_ccb *ccb);
39 
40 /*
41  * This is called for PM attachments and hot-plug insertion events, and
42  * typically not called again until after an unplug/replug sequence.
43  *
44  * We just fall through to the hard-reset code, we don't need to
45  * set up any initial conditions.
46  */
47 int
48 sili_pm_port_init(struct sili_port *ap, struct ata_port *at)
49 {
50 	at->at_probe = ATA_PROBE_NEED_HARD_RESET;
51 	return (0);
52 }
53 
54 /*
55  * This is called from the port hardreset code.
56  */
57 int
58 sili_pm_port_probe(struct sili_port *ap, int orig_error)
59 {
60 	struct ata_port *at;
61 	int error;
62 	int i;
63 
64 	/*
65 	 * Clean up the port state machine
66 	 */
67 	sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_PMA);
68 	sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_INIT);
69 	if (sili_pwait_clr_to(ap, 5000, SILI_PREG_STATUS, SILI_PREG_CTL_INIT)) {
70 		kprintf("%s: PM probe: unable to init port\n",
71 			PORTNAME(ap));
72 		return (EBUSY);
73 	}
74 	if (sili_pwait_set(ap, SILI_PREG_STATUS, SILI_PREG_STATUS_READY)) {
75 		kprintf("%s: PM probe: port will not come ready\n",
76 			PORTNAME(ap));
77 		return (EBUSY);
78 	}
79 
80 	/*
81 	 * Issue a soft-reset of target 15
82 	 */
83 	ap->ap_state = AP_S_NORMAL;
84 	sili_pwrite(ap, SILI_PREG_SERR, -1);
85 	error = sili_pm_softreset(ap, 15);
86 
87 	if (error == 0)
88 		error = sili_pm_identify(ap);
89 
90 	/*
91 	 * Finalize.  If the softreset failed.  Re-init the port
92 	 * state machine again so the normal non-PM softreset does
93 	 * not bog down.
94 	 */
95 	if (error == 0) {
96 		for (i = 0; i < SILI_MAX_PMPORTS; ++i) {
97 			at = &ap->ap_ata[i];
98 			at->at_probe = ATA_PROBE_NEED_INIT;
99 			at->at_features |= ATA_PORT_F_RESCAN;
100 			at->at_features &= ~ATA_PORT_F_READLOG;
101 		}
102 		ap->ap_type = ATA_PORT_T_PM;
103 		return (0);
104 	}
105 
106 	sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_PMA);
107 	sili_port_init(ap);
108 	if (orig_error == 0) {
109 		if (sili_pwait_set_to(ap, 5000, SILI_PREG_STATUS,
110 				      SILI_PREG_STATUS_READY)) {
111 			kprintf("%s: PM probe: port will not come ready\n",
112 				PORTNAME(ap));
113 			orig_error = EBUSY;
114 		}
115 	}
116 	return (orig_error);
117 
118 #if 0
119 	sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESUME);
120 	sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_PMA);
121 	sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_INIT);
122 	if (sili_pwait_clr_to(ap, 5000, SILI_PREG_STATUS, SILI_PREG_CTL_INIT)) {
123 		kprintf("%s: PM probe: unable to init port\n",
124 			PORTNAME(ap));
125 		orig_error = EBUSY;
126 	}
127 	if (sili_pwait_set(ap, SILI_PREG_STATUS, SILI_PREG_STATUS_READY)) {
128 		kprintf("%s: PM probe: port will not come ready\n",
129 			PORTNAME(ap));
130 		orig_error = EBUSY;
131 	}
132 	kprintf("ORIG ERROR %d\n", orig_error);
133 	if (orig_error)
134 		return (orig_error);
135 
136 	/*
137 	 * If we originally detected a device redo the device reset to
138 	 * try to clear the mess.
139 	 */
140 	sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_DEVRESET);
141 	if (sili_pwait_clr(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_DEVRESET)) {
142 		kprintf("%s: PM probe: unable to reset\n", PORTNAME(ap));
143 		orig_error = EBUSY;
144 	}
145 	if (sili_pwait_set(ap, SILI_PREG_STATUS, SILI_PREG_STATUS_READY)) {
146 		kprintf("%s: PM probe: port will not come ready\n",
147 			PORTNAME(ap));
148 		orig_error = EBUSY;
149 	}
150 	return (orig_error);
151 #endif
152 }
153 
154 /*
155  * Identify the port multiplier
156  */
157 int
158 sili_pm_identify(struct sili_port *ap)
159 {
160 	u_int32_t chipid;
161 	u_int32_t rev;
162 	u_int32_t nports;
163 	u_int32_t data1;
164 	u_int32_t data2;
165 
166 	ap->ap_probe = ATA_PROBE_FAILED;
167 	if (sili_pm_read(ap, 15, 0, &chipid))
168 		goto err;
169 	if (sili_pm_read(ap, 15, 1, &rev))
170 		goto err;
171 	if (sili_pm_read(ap, 15, 2, &nports))
172 		goto err;
173 	nports &= 0x0000000F;	/* only the low 4 bits */
174 	ap->ap_probe = ATA_PROBE_GOOD;
175 	kprintf("%s: Port multiplier: chip=%08x rev=0x%b nports=%d\n",
176 		PORTNAME(ap),
177 		chipid,
178 		rev, SATA_PFMT_PM_REV,
179 		nports);
180 	ap->ap_pmcount = nports;
181 
182 	if (sili_pm_read(ap, 15, SATA_PMREG_FEA, &data1)) {
183 		kprintf("%s: Port multiplier: Warning, "
184 			"cannot read feature register\n", PORTNAME(ap));
185 	} else {
186 		kprintf("%s: Port multiplier features: 0x%b\n",
187 			PORTNAME(ap),
188 			data1,
189 			SATA_PFMT_PM_FEA);
190 	}
191 	if (sili_pm_read(ap, 15, SATA_PMREG_FEAEN, &data2) == 0) {
192 		kprintf("%s: Port multiplier defaults: 0x%b\n",
193 			PORTNAME(ap),
194 			data2,
195 			SATA_PFMT_PM_FEA);
196 	}
197 
198 	/*
199 	 * Turn on async notification if we support and the PM supports it.
200 	 * This allows the PM to forward async notification events to us and
201 	 * it will also generate an event for target 15 for hot-plug events
202 	 * (or is supposed to anyway).
203 	 */
204 	if ((ap->ap_sc->sc_flags & SILI_F_SSNTF) &&
205 	    (data1 & SATA_PMFEA_ASYNCNOTIFY)) {
206 		u_int32_t serr_bits = SATA_PM_SERR_DIAG_N |
207 				      SATA_PM_SERR_DIAG_X;
208 		data2 |= SATA_PMFEA_ASYNCNOTIFY;
209 		if (sili_pm_write(ap, 15, SATA_PMREG_FEAEN, data2)) {
210 			kprintf("%s: Port multiplier: AsyncNotify cannot be "
211 				"enabled\n", PORTNAME(ap));
212 		} else if (sili_pm_write(ap, 15, SATA_PMREG_EEENA, serr_bits)) {
213 			kprintf("%s: Port mulltiplier: AsyncNotify unable "
214 				"to enable error info bits\n", PORTNAME(ap));
215 		} else {
216 			kprintf("%s: Port multiplier: AsyncNotify enabled\n",
217 				PORTNAME(ap));
218 		}
219 	}
220 
221 	return (0);
222 err:
223 	kprintf("%s: Port multiplier cannot be identified\n", PORTNAME(ap));
224 	return (EIO);
225 }
226 
227 /*
228  * Do a COMRESET sequence on the target behind a port multiplier.
229  *
230  * If hard is 2 we also cycle the phy on the target.
231  *
232  * This must be done prior to any softreset or probe attempts on
233  * targets behind the port multiplier.
234  *
235  * Returns 0 on success or an error.
236  */
237 int
238 sili_pm_hardreset(struct sili_port *ap, int target, int hard)
239 {
240 	struct ata_port *at;
241 	u_int32_t data;
242 	int loop;
243 	int error = EIO;
244 
245 	at = &ap->ap_ata[target];
246 
247 	/*
248 	 * Turn off power management and kill the phy on the target
249 	 * if requested.  Hold state for 10ms.
250 	 */
251 	data = SATA_PM_SCTL_IPM_DISABLED;
252 	if (hard == 2)
253 		data |= SATA_PM_SCTL_DET_DISABLE;
254 	if (sili_pm_write(ap, target, SATA_PMREG_SERR, -1))
255 		goto err;
256 	if (sili_pm_write(ap, target, SATA_PMREG_SCTL, data))
257 		goto err;
258 	sili_os_sleep(10);
259 
260 	/*
261 	 * Start transmitting COMRESET.  COMRESET must be sent for at
262 	 * least 1ms.
263 	 */
264 	at->at_probe = ATA_PROBE_FAILED;
265 	at->at_type = ATA_PORT_T_NONE;
266 	data = SATA_PM_SCTL_IPM_DISABLED | SATA_PM_SCTL_DET_INIT;
267 	if (SiliForceGen1 & (1 << ap->ap_num)) {
268 		kprintf("%s.%d: Force 1.5GBits\n", PORTNAME(ap), target);
269 		data |= SATA_PM_SCTL_SPD_GEN1;
270 	} else {
271 		data |= SATA_PM_SCTL_SPD_ANY;
272 	}
273 	if (sili_pm_write(ap, target, SATA_PMREG_SCTL, data))
274 		goto err;
275 
276 	/*
277 	 * It takes about 100ms for the DET logic to settle down,
278 	 * from trial and error testing.  If this is too short
279 	 * the softreset code will fail.
280 	 */
281 	sili_os_sleep(100);
282 
283 	if (sili_pm_phy_status(ap, target, &data)) {
284 		kprintf("%s: (A)Cannot clear phy status\n",
285 			ATANAME(ap ,at));
286 	}
287 
288 	/*
289 	 * Flush any status, then clear DET to initiate negotiation.
290 	 *
291 	 * We need to give the phy layer a bit of time to settle down
292 	 * or we may catch a detection glitch instead of the actual
293 	 * device detect.
294 	 */
295 	sili_pm_write(ap, target, SATA_PMREG_SERR, -1);
296 	data = SATA_PM_SCTL_IPM_DISABLED | SATA_PM_SCTL_DET_NONE;
297 	if (sili_pm_write(ap, target, SATA_PMREG_SCTL, data))
298 		goto err;
299 	sili_os_sleep(10);
300 
301 	/*
302 	 * Try to determine if there is a device on the port.
303 	 *
304 	 * Give the device 3/10 second to at least be detected.
305 	 * If we fail clear any pending status since we may have
306 	 * cycled the phy and probably caused another PRCS interrupt.
307 	 */
308 	for (loop = 3; loop; --loop) {
309 		if (sili_pm_read(ap, target, SATA_PMREG_SSTS, &data))
310 			goto err;
311 		if (data & SATA_PM_SSTS_DET)
312 			break;
313 		sili_os_sleep(100);
314 	}
315 	if (loop == 0) {
316 		kprintf("%s.%d: Port appears to be unplugged\n",
317 			PORTNAME(ap), target);
318 		error = ENODEV;
319 		goto err;
320 	}
321 
322 	/*
323 	 * There is something on the port.  Give the device 3 seconds
324 	 * to fully negotiate.
325 	 */
326 	for (loop = 30; loop; --loop) {
327 		if (sili_pm_read(ap, target, SATA_PMREG_SSTS, &data))
328 			goto err;
329 		if ((data & SATA_PM_SSTS_DET) == SATA_PM_SSTS_DET_DEV)
330 			break;
331 		sili_os_sleep(100);
332 	}
333 
334 	/*
335 	 * Device not detected
336 	 */
337 	if (loop == 0) {
338 		kprintf("%s: Device may be powered down\n",
339 			PORTNAME(ap));
340 		error = ENODEV;
341 		goto err;
342 	}
343 
344 	/*
345 	 * Device detected.
346 	 *
347 	 * Wait 200ms to give the device time to send its first D2H FIS.
348 	 * If we do not wait long enough our softreset sequence can collide
349 	 * with the end of the device's reset sequence.
350 	 *
351 	 * XXX how do we poll that particular target's BSY status via the
352 	 *     PM?
353 	 */
354 	kprintf("%s.%d: Device detected data=%08x\n",
355 		PORTNAME(ap), target, data);
356 	sili_os_sleep(200);
357 
358 	error = 0;
359 err:
360 	at->at_probe = error ? ATA_PROBE_FAILED : ATA_PROBE_NEED_SOFT_RESET;
361 	return (error);
362 }
363 
364 /*
365  * SILI soft reset through port multiplier.
366  *
367  * This function keeps port communications intact and attempts to generate
368  * a reset to the connected device using device commands.  Unlike
369  * hard-port operations we can't do fancy stop/starts or stuff like
370  * that without messing up other commands that might be running or
371  * queued.
372  *
373  * The SII chip will do the whole mess for us.
374  */
375 int
376 sili_pm_softreset(struct sili_port *ap, int target)
377 {
378 	struct ata_port		*at;
379 	struct sili_ccb		*ccb;
380 	struct sili_prb		*prb;
381 	int			error;
382 	u_int32_t		data;
383 	u_int32_t		sig;
384 	int			timeout;
385 
386 	error = EIO;
387 	at = &ap->ap_ata[target];
388 
389 	DPRINTF(SILI_D_VERBOSE, "%s: soft reset\n", PORTNAME(ap));
390 
391 	/*
392 	 * Prep the special soft-reset SII command.
393 	 */
394 	ccb = sili_get_err_ccb(ap);
395 	ccb->ccb_done = sili_pm_empty_done;
396 	ccb->ccb_xa.flags = ATA_F_POLL | ATA_F_EXCLUSIVE | ATA_F_AUTOSENSE;
397 	ccb->ccb_xa.complete = sili_pm_dummy_done;
398 	ccb->ccb_xa.at = at;
399 
400 	prb = ccb->ccb_prb;
401 	bzero(&prb->prb_h2d, sizeof(prb->prb_h2d));
402 	prb->prb_h2d.flags = at->at_target;
403 	prb->prb_control = SILI_PRB_CTRL_SOFTRESET;
404 	prb->prb_override = 0;
405 	prb->prb_xfer_count = 0;
406 
407 	ccb->ccb_xa.state = ATA_S_PENDING;
408 
409 	timeout = (target == 15) ? 1000 : 8000;
410 
411 	/*
412 	 * NOTE: Must use sili_quick_timeout() because we hold the err_ccb
413 	 */
414 	if (sili_poll(ccb, timeout, sili_quick_timeout) != ATA_S_COMPLETE) {
415 		if (target != 15) {
416 			kprintf("%s: (PM) Softreset FIS failed\n",
417 				ATANAME(ap, at));
418 		}
419 		sili_put_err_ccb(ccb);
420 		goto err;
421 	}
422 
423 	sig = (prb->prb_d2h.lba_high << 24) |
424 	      (prb->prb_d2h.lba_mid << 16) |
425 	      (prb->prb_d2h.lba_low << 8) |
426 	      (prb->prb_d2h.sector_count);
427 	kprintf("%s: PM SOFTRESET SIGNATURE %08x\n", ATANAME(ap, at), sig);
428 
429 	sili_put_err_ccb(ccb);
430 
431 	/*
432 	 * Clear the phy status of the target so we can get a new event.
433 	 *
434 	 * Target 15 is the PM itself and these registers have
435 	 * different meanings.
436 	 */
437 	if (target != 15) {
438 		if (sili_pm_phy_status(ap, target, &data)) {
439 			kprintf("%s: (C)Cannot clear phy status\n",
440 				ATANAME(ap ,at));
441 		}
442 		sili_pm_write(ap, target, SATA_PMREG_SERR, -1);
443 	}
444 
445 	/*
446 	 * If the softreset is trying to clear a BSY condition after a
447 	 * normal portreset we assign the port type.
448 	 *
449 	 * If the softreset is being run first as part of the ccb error
450 	 * processing code then report if the device signature changed
451 	 * unexpectedly.
452 	 */
453 	if (at->at_type == ATA_PORT_T_NONE) {
454 		at->at_type = sili_port_signature(ap, at, sig);
455 	} else {
456 		if (sili_port_signature(ap, at, sig) != at->at_type) {
457 			kprintf("%s: device signature unexpectedly "
458 				"changed\n", ATANAME(ap, at));
459 			error = EBUSY; /* XXX */
460 		}
461 	}
462 	error = 0;
463 err:
464 	/*
465 	 * Clear error status so we can detect removal.
466 	 *
467 	 * Target 15 is the PM itself and these registers have
468 	 * different meanings.
469 	 */
470 	if (error == 0 && target != 15) {
471 		if (sili_pm_write(ap, target, SATA_PMREG_SERR, -1)) {
472 			kprintf("%s: sili_pm_softreset unable to clear SERR\n",
473 				ATANAME(ap, at));
474 			ap->ap_flags &= ~AP_F_IGNORE_IFS;
475 		}
476 	}
477 
478 	at->at_probe = error ? ATA_PROBE_FAILED : ATA_PROBE_NEED_IDENT;
479 	return (error);
480 }
481 
482 
483 /*
484  * Return the phy status for a target behind a port multiplier and
485  * reset SATA_PMREG_SERR.
486  *
487  * Returned bits follow SILI_PREG_SSTS bits.  The SILI_PREG_SSTS_SPD
488  * bits can be used to determine the link speed and will be 0 if there
489  * is no link.
490  *
491  * 0 is returned if any communications error occurs.
492  */
493 int
494 sili_pm_phy_status(struct sili_port *ap, int target, u_int32_t *datap)
495 {
496 	int error;
497 
498 	error = sili_pm_read(ap, target, SATA_PMREG_SSTS, datap);
499 	if (error == 0)
500 		error = sili_pm_write(ap, target, SATA_PMREG_SERR, -1);
501 	if (error)
502 		*datap = 0;
503 	return(error);
504 }
505 
506 int
507 sili_pm_set_feature(struct sili_port *ap, int feature, int enable)
508 {
509 	struct ata_xfer	*xa;
510 	int error;
511 
512 	xa = sili_ata_get_xfer(ap, &ap->ap_ata[15]);
513 
514 	xa->fis->type = ATA_FIS_TYPE_H2D;
515 	xa->fis->flags = ATA_H2D_FLAGS_CMD | 15;
516 	xa->fis->command = enable ? ATA_C_SATA_FEATURE_ENA :
517 				    ATA_C_SATA_FEATURE_DIS;
518 	xa->fis->sector_count = feature;
519 	xa->fis->control = ATA_FIS_CONTROL_4BIT;
520 
521 	xa->complete = sili_pm_dummy_done;
522 	xa->datalen = 0;
523 	xa->flags = ATA_F_POLL | ATA_F_EXCLUSIVE;
524 	xa->timeout = 1000;
525 
526 	if (sili_ata_cmd(xa) == ATA_S_COMPLETE)
527 		error = 0;
528 	else
529 		error = EIO;
530 	sili_ata_put_xfer(xa);
531 	return(error);
532 }
533 
534 /*
535  * Check that a target is still good.
536  */
537 void
538 sili_pm_check_good(struct sili_port *ap, int target)
539 {
540 	struct ata_port *at;
541 	u_int32_t data;
542 
543 	/*
544 	 * It looks like we might have to read the EINFO register
545 	 * to allow the PM to generate a new event.
546 	 */
547 	if (sili_pm_read(ap, 15, SATA_PMREG_EINFO, &data)) {
548 		kprintf("%s: Port multiplier EINFO could not be read\n",
549 			PORTNAME(ap));
550 	}
551 
552 	if (sili_pm_write(ap, target, SATA_PMREG_SERR, -1)) {
553 		kprintf("%s: Port multiplier: SERR could not be cleared\n",
554 			PORTNAME(ap));
555 	}
556 
557 	if (target == CAM_TARGET_WILDCARD || target >= ap->ap_pmcount)
558 		return;
559 	at = &ap->ap_ata[target];
560 
561 	/*
562 	 * If the device needs an init or hard reset also make sure the
563 	 * PHY is turned on.
564 	 */
565 	if (at->at_probe <= ATA_PROBE_NEED_HARD_RESET) {
566 		/*kprintf("%s DOHARD\n", ATANAME(ap, at));*/
567 		sili_pm_hardreset(ap, target, 1);
568 	}
569 
570 	/*
571 	 * Read the detect status
572 	 */
573 	if (sili_pm_read(ap, target, SATA_PMREG_SSTS, &data)) {
574 		kprintf("%s: Unable to access PM SSTS register target %d\n",
575 			PORTNAME(ap), target);
576 		return;
577 	}
578 	if ((data & SATA_PM_SSTS_DET) != SATA_PM_SSTS_DET_DEV) {
579 		/*kprintf("%s: DETECT %08x\n", ATANAME(ap, at), data);*/
580 		if (at->at_probe != ATA_PROBE_FAILED) {
581 			at->at_probe = ATA_PROBE_FAILED;
582 			at->at_type = ATA_PORT_T_NONE;
583 			at->at_features |= ATA_PORT_F_RESCAN;
584 			kprintf("%s: HOTPLUG (PM) - Device removed\n",
585 				ATANAME(ap, at));
586 		}
587 	} else {
588 		if (at->at_probe == ATA_PROBE_FAILED) {
589 			at->at_probe = ATA_PROBE_NEED_HARD_RESET;
590 			at->at_features |= ATA_PORT_F_RESCAN;
591 			kprintf("%s: HOTPLUG (PM) - Device inserted\n",
592 				ATANAME(ap, at));
593 		}
594 	}
595 }
596 
597 /*
598  * Read a PM register
599  */
600 int
601 sili_pm_read(struct sili_port *ap, int target, int which, u_int32_t *datap)
602 {
603 	struct ata_xfer	*xa;
604 	int error;
605 
606 	xa = sili_ata_get_xfer(ap, &ap->ap_ata[15]);
607 
608 	xa->fis->type = ATA_FIS_TYPE_H2D;
609 	xa->fis->flags = ATA_H2D_FLAGS_CMD | 15;
610 	xa->fis->command = ATA_C_READ_PM;
611 	xa->fis->features = which;
612 	xa->fis->device = target | ATA_H2D_DEVICE_LBA;
613 	xa->fis->control = ATA_FIS_CONTROL_4BIT;
614 
615 	xa->complete = sili_pm_dummy_done;
616 	xa->datalen = 0;
617 	xa->flags = ATA_F_POLL | ATA_F_AUTOSENSE;
618 	xa->timeout = 1000;
619 
620 	if (sili_ata_cmd(xa) == ATA_S_COMPLETE) {
621 		*datap = xa->rfis->sector_count | (xa->rfis->lba_low << 8) |
622 		       (xa->rfis->lba_mid << 16) | (xa->rfis->lba_high << 24);
623 		error = 0;
624 	} else {
625 		kprintf("%s.%d pm_read SCA[%d] failed\n",
626 			PORTNAME(ap), target, which);
627 		*datap = 0;
628 		error = EIO;
629 	}
630 	sili_ata_put_xfer(xa);
631 	return (error);
632 }
633 
634 /*
635  * Write a PM register
636  */
637 int
638 sili_pm_write(struct sili_port *ap, int target, int which, u_int32_t data)
639 {
640 	struct ata_xfer	*xa;
641 	int error;
642 
643 	xa = sili_ata_get_xfer(ap, &ap->ap_ata[15]);
644 
645 	xa->fis->type = ATA_FIS_TYPE_H2D;
646 	xa->fis->flags = ATA_H2D_FLAGS_CMD | 15;
647 	xa->fis->command = ATA_C_WRITE_PM;
648 	xa->fis->features = which;
649 	xa->fis->device = target | ATA_H2D_DEVICE_LBA;
650 	xa->fis->sector_count = (u_int8_t)data;
651 	xa->fis->lba_low = (u_int8_t)(data >> 8);
652 	xa->fis->lba_mid = (u_int8_t)(data >> 16);
653 	xa->fis->lba_high = (u_int8_t)(data >> 24);
654 	xa->fis->control = ATA_FIS_CONTROL_4BIT;
655 
656 	xa->complete = sili_pm_dummy_done;
657 	xa->datalen = 0;
658 	xa->flags = ATA_F_POLL | ATA_F_EXCLUSIVE;
659 	xa->timeout = 1000;
660 
661 	if (sili_ata_cmd(xa) == ATA_S_COMPLETE)
662 		error = 0;
663 	else
664 		error = EIO;
665 	sili_ata_put_xfer(xa);
666 	return(error);
667 }
668 
669 /*
670  * Dummy done callback for xa.
671  */
672 static void
673 sili_pm_dummy_done(struct ata_xfer *xa)
674 {
675 }
676 
677 static void
678 sili_pm_empty_done(struct sili_ccb *ccb)
679 {
680 }
681