xref: /openbmc/linux/drivers/ata/libahci_platform.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
1 /*
2  * AHCI SATA platform library
3  *
4  * Copyright 2004-2005  Red Hat, Inc.
5  *   Jeff Garzik <jgarzik@pobox.com>
6  * Copyright 2010  MontaVista Software, LLC.
7  *   Anton Vorontsov <avorontsov@ru.mvista.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2, or (at your option)
12  * any later version.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/kernel.h>
17 #include <linux/gfp.h>
18 #include <linux/module.h>
19 #include <linux/pm.h>
20 #include <linux/interrupt.h>
21 #include <linux/device.h>
22 #include <linux/platform_device.h>
23 #include <linux/libata.h>
24 #include <linux/ahci_platform.h>
25 #include <linux/phy/phy.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/of_platform.h>
28 #include <linux/reset.h>
29 #include "ahci.h"
30 
31 static void ahci_host_stop(struct ata_host *host);
32 
33 struct ata_port_operations ahci_platform_ops = {
34 	.inherits	= &ahci_ops,
35 	.host_stop	= ahci_host_stop,
36 };
37 EXPORT_SYMBOL_GPL(ahci_platform_ops);
38 
39 /**
40  * ahci_platform_enable_phys - Enable PHYs
41  * @hpriv: host private area to store config values
42  *
43  * This function enables all the PHYs found in hpriv->phys, if any.
44  * If a PHY fails to be enabled, it disables all the PHYs already
45  * enabled in reverse order and returns an error.
46  *
47  * RETURNS:
48  * 0 on success otherwise a negative error code
49  */
50 static int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
51 {
52 	int rc, i;
53 
54 	for (i = 0; i < hpriv->nports; i++) {
55 		rc = phy_init(hpriv->phys[i]);
56 		if (rc)
57 			goto disable_phys;
58 
59 		rc = phy_power_on(hpriv->phys[i]);
60 		if (rc) {
61 			phy_exit(hpriv->phys[i]);
62 			goto disable_phys;
63 		}
64 	}
65 
66 	return 0;
67 
68 disable_phys:
69 	while (--i >= 0) {
70 		phy_power_off(hpriv->phys[i]);
71 		phy_exit(hpriv->phys[i]);
72 	}
73 	return rc;
74 }
75 
76 /**
77  * ahci_platform_disable_phys - Disable PHYs
78  * @hpriv: host private area to store config values
79  *
80  * This function disables all PHYs found in hpriv->phys.
81  */
82 static void ahci_platform_disable_phys(struct ahci_host_priv *hpriv)
83 {
84 	int i;
85 
86 	for (i = 0; i < hpriv->nports; i++) {
87 		phy_power_off(hpriv->phys[i]);
88 		phy_exit(hpriv->phys[i]);
89 	}
90 }
91 
92 /**
93  * ahci_platform_enable_clks - Enable platform clocks
94  * @hpriv: host private area to store config values
95  *
96  * This function enables all the clks found in hpriv->clks, starting at
97  * index 0. If any clk fails to enable it disables all the clks already
98  * enabled in reverse order, and then returns an error.
99  *
100  * RETURNS:
101  * 0 on success otherwise a negative error code
102  */
103 int ahci_platform_enable_clks(struct ahci_host_priv *hpriv)
104 {
105 	int c, rc;
106 
107 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++) {
108 		rc = clk_prepare_enable(hpriv->clks[c]);
109 		if (rc)
110 			goto disable_unprepare_clk;
111 	}
112 	return 0;
113 
114 disable_unprepare_clk:
115 	while (--c >= 0)
116 		clk_disable_unprepare(hpriv->clks[c]);
117 	return rc;
118 }
119 EXPORT_SYMBOL_GPL(ahci_platform_enable_clks);
120 
121 /**
122  * ahci_platform_disable_clks - Disable platform clocks
123  * @hpriv: host private area to store config values
124  *
125  * This function disables all the clks found in hpriv->clks, in reverse
126  * order of ahci_platform_enable_clks (starting at the end of the array).
127  */
128 void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
129 {
130 	int c;
131 
132 	for (c = AHCI_MAX_CLKS - 1; c >= 0; c--)
133 		if (hpriv->clks[c])
134 			clk_disable_unprepare(hpriv->clks[c]);
135 }
136 EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
137 
138 /**
139  * ahci_platform_enable_regulators - Enable regulators
140  * @hpriv: host private area to store config values
141  *
142  * This function enables all the regulators found in controller and
143  * hpriv->target_pwrs, if any.  If a regulator fails to be enabled, it
144  * disables all the regulators already enabled in reverse order and
145  * returns an error.
146  *
147  * RETURNS:
148  * 0 on success otherwise a negative error code
149  */
150 int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
151 {
152 	int rc, i;
153 
154 	if (hpriv->ahci_regulator) {
155 		rc = regulator_enable(hpriv->ahci_regulator);
156 		if (rc)
157 			return rc;
158 	}
159 
160 	if (hpriv->phy_regulator) {
161 		rc = regulator_enable(hpriv->phy_regulator);
162 		if (rc)
163 			goto disable_ahci_pwrs;
164 	}
165 
166 	for (i = 0; i < hpriv->nports; i++) {
167 		if (!hpriv->target_pwrs[i])
168 			continue;
169 
170 		rc = regulator_enable(hpriv->target_pwrs[i]);
171 		if (rc)
172 			goto disable_target_pwrs;
173 	}
174 
175 	return 0;
176 
177 disable_target_pwrs:
178 	while (--i >= 0)
179 		if (hpriv->target_pwrs[i])
180 			regulator_disable(hpriv->target_pwrs[i]);
181 
182 	if (hpriv->phy_regulator)
183 		regulator_disable(hpriv->phy_regulator);
184 disable_ahci_pwrs:
185 	if (hpriv->ahci_regulator)
186 		regulator_disable(hpriv->ahci_regulator);
187 	return rc;
188 }
189 EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
190 
191 /**
192  * ahci_platform_disable_regulators - Disable regulators
193  * @hpriv: host private area to store config values
194  *
195  * This function disables all regulators found in hpriv->target_pwrs and
196  * AHCI controller.
197  */
198 void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
199 {
200 	int i;
201 
202 	for (i = 0; i < hpriv->nports; i++) {
203 		if (!hpriv->target_pwrs[i])
204 			continue;
205 		regulator_disable(hpriv->target_pwrs[i]);
206 	}
207 
208 	if (hpriv->ahci_regulator)
209 		regulator_disable(hpriv->ahci_regulator);
210 	if (hpriv->phy_regulator)
211 		regulator_disable(hpriv->phy_regulator);
212 }
213 EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
214 /**
215  * ahci_platform_enable_resources - Enable platform resources
216  * @hpriv: host private area to store config values
217  *
218  * This function enables all ahci_platform managed resources in the
219  * following order:
220  * 1) Regulator
221  * 2) Clocks (through ahci_platform_enable_clks)
222  * 3) Resets
223  * 4) Phys
224  *
225  * If resource enabling fails at any point the previous enabled resources
226  * are disabled in reverse order.
227  *
228  * RETURNS:
229  * 0 on success otherwise a negative error code
230  */
231 int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
232 {
233 	int rc;
234 
235 	rc = ahci_platform_enable_regulators(hpriv);
236 	if (rc)
237 		return rc;
238 
239 	rc = ahci_platform_enable_clks(hpriv);
240 	if (rc)
241 		goto disable_regulator;
242 
243 	rc = reset_control_deassert(hpriv->rsts);
244 	if (rc)
245 		goto disable_clks;
246 
247 	rc = ahci_platform_enable_phys(hpriv);
248 	if (rc)
249 		goto disable_resets;
250 
251 	return 0;
252 
253 disable_resets:
254 	reset_control_assert(hpriv->rsts);
255 
256 disable_clks:
257 	ahci_platform_disable_clks(hpriv);
258 
259 disable_regulator:
260 	ahci_platform_disable_regulators(hpriv);
261 
262 	return rc;
263 }
264 EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
265 
266 /**
267  * ahci_platform_disable_resources - Disable platform resources
268  * @hpriv: host private area to store config values
269  *
270  * This function disables all ahci_platform managed resources in the
271  * following order:
272  * 1) Phys
273  * 2) Resets
274  * 3) Clocks (through ahci_platform_disable_clks)
275  * 4) Regulator
276  */
277 void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
278 {
279 	ahci_platform_disable_phys(hpriv);
280 
281 	reset_control_assert(hpriv->rsts);
282 
283 	ahci_platform_disable_clks(hpriv);
284 
285 	ahci_platform_disable_regulators(hpriv);
286 }
287 EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
288 
289 static void ahci_platform_put_resources(struct device *dev, void *res)
290 {
291 	struct ahci_host_priv *hpriv = res;
292 	int c;
293 
294 	if (hpriv->got_runtime_pm) {
295 		pm_runtime_put_sync(dev);
296 		pm_runtime_disable(dev);
297 	}
298 
299 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
300 		clk_put(hpriv->clks[c]);
301 	/*
302 	 * The regulators are tied to child node device and not to the
303 	 * SATA device itself. So we can't use devm for automatically
304 	 * releasing them. We have to do it manually here.
305 	 */
306 	for (c = 0; c < hpriv->nports; c++)
307 		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
308 			regulator_put(hpriv->target_pwrs[c]);
309 
310 	kfree(hpriv->target_pwrs);
311 }
312 
313 static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
314 				struct device *dev, struct device_node *node)
315 {
316 	int rc;
317 
318 	hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
319 
320 	if (!IS_ERR(hpriv->phys[port]))
321 		return 0;
322 
323 	rc = PTR_ERR(hpriv->phys[port]);
324 	switch (rc) {
325 	case -ENOSYS:
326 		/* No PHY support. Check if PHY is required. */
327 		if (of_find_property(node, "phys", NULL)) {
328 			dev_err(dev,
329 				"couldn't get PHY in node %pOFn: ENOSYS\n",
330 				node);
331 			break;
332 		}
333 		/* fall through */
334 	case -ENODEV:
335 		/* continue normally */
336 		hpriv->phys[port] = NULL;
337 		rc = 0;
338 		break;
339 
340 	default:
341 		dev_err(dev,
342 			"couldn't get PHY in node %pOFn: %d\n",
343 			node, rc);
344 
345 		break;
346 	}
347 
348 	return rc;
349 }
350 
351 static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
352 				struct device *dev)
353 {
354 	struct regulator *target_pwr;
355 	int rc = 0;
356 
357 	target_pwr = regulator_get_optional(dev, "target");
358 
359 	if (!IS_ERR(target_pwr))
360 		hpriv->target_pwrs[port] = target_pwr;
361 	else
362 		rc = PTR_ERR(target_pwr);
363 
364 	return rc;
365 }
366 
367 /**
368  * ahci_platform_get_resources - Get platform resources
369  * @pdev: platform device to get resources for
370  * @flags: bitmap representing the resource to get
371  *
372  * This function allocates an ahci_host_priv struct, and gets the following
373  * resources, storing a reference to them inside the returned struct:
374  *
375  * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
376  * 2) regulator for controlling the targets power (optional)
377  *    regulator for controlling the AHCI controller (optional)
378  * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
379  *    or for non devicetree enabled platforms a single clock
380  * 4) resets, if flags has AHCI_PLATFORM_GET_RESETS (optional)
381  * 5) phys (optional)
382  *
383  * RETURNS:
384  * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
385  */
386 struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
387 						   unsigned int flags)
388 {
389 	struct device *dev = &pdev->dev;
390 	struct ahci_host_priv *hpriv;
391 	struct clk *clk;
392 	struct device_node *child;
393 	int i, enabled_ports = 0, rc = -ENOMEM, child_nodes;
394 	u32 mask_port_map = 0;
395 
396 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
397 		return ERR_PTR(-ENOMEM);
398 
399 	hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
400 			     GFP_KERNEL);
401 	if (!hpriv)
402 		goto err_out;
403 
404 	devres_add(dev, hpriv);
405 
406 	hpriv->mmio = devm_ioremap_resource(dev,
407 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
408 	if (IS_ERR(hpriv->mmio)) {
409 		dev_err(dev, "no mmio space\n");
410 		rc = PTR_ERR(hpriv->mmio);
411 		goto err_out;
412 	}
413 
414 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
415 		/*
416 		 * For now we must use clk_get(dev, NULL) for the first clock,
417 		 * because some platforms (da850, spear13xx) are not yet
418 		 * converted to use devicetree for clocks.  For new platforms
419 		 * this is equivalent to of_clk_get(dev->of_node, 0).
420 		 */
421 		if (i == 0)
422 			clk = clk_get(dev, NULL);
423 		else
424 			clk = of_clk_get(dev->of_node, i);
425 
426 		if (IS_ERR(clk)) {
427 			rc = PTR_ERR(clk);
428 			if (rc == -EPROBE_DEFER)
429 				goto err_out;
430 			break;
431 		}
432 		hpriv->clks[i] = clk;
433 	}
434 
435 	hpriv->ahci_regulator = devm_regulator_get_optional(dev, "ahci");
436 	if (IS_ERR(hpriv->ahci_regulator)) {
437 		rc = PTR_ERR(hpriv->ahci_regulator);
438 		if (rc == -EPROBE_DEFER)
439 			goto err_out;
440 		rc = 0;
441 		hpriv->ahci_regulator = NULL;
442 	}
443 
444 	hpriv->phy_regulator = devm_regulator_get_optional(dev, "phy");
445 	if (IS_ERR(hpriv->phy_regulator)) {
446 		rc = PTR_ERR(hpriv->phy_regulator);
447 		if (rc == -EPROBE_DEFER)
448 			goto err_out;
449 		rc = 0;
450 		hpriv->phy_regulator = NULL;
451 	}
452 
453 	if (flags & AHCI_PLATFORM_GET_RESETS) {
454 		hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
455 		if (IS_ERR(hpriv->rsts)) {
456 			rc = PTR_ERR(hpriv->rsts);
457 			goto err_out;
458 		}
459 	}
460 
461 	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
462 
463 	/*
464 	 * If no sub-node was found, we still need to set nports to
465 	 * one in order to be able to use the
466 	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
467 	 */
468 	if (!child_nodes)
469 		hpriv->nports = 1;
470 
471 	hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);
472 	if (!hpriv->phys) {
473 		rc = -ENOMEM;
474 		goto err_out;
475 	}
476 	/*
477 	 * We cannot use devm_ here, since ahci_platform_put_resources() uses
478 	 * target_pwrs after devm_ have freed memory
479 	 */
480 	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
481 	if (!hpriv->target_pwrs) {
482 		rc = -ENOMEM;
483 		goto err_out;
484 	}
485 
486 	if (child_nodes) {
487 		for_each_child_of_node(dev->of_node, child) {
488 			u32 port;
489 			struct platform_device *port_dev __maybe_unused;
490 
491 			if (!of_device_is_available(child))
492 				continue;
493 
494 			if (of_property_read_u32(child, "reg", &port)) {
495 				rc = -EINVAL;
496 				goto err_out;
497 			}
498 
499 			if (port >= hpriv->nports) {
500 				dev_warn(dev, "invalid port number %d\n", port);
501 				continue;
502 			}
503 			mask_port_map |= BIT(port);
504 
505 #ifdef CONFIG_OF_ADDRESS
506 			of_platform_device_create(child, NULL, NULL);
507 
508 			port_dev = of_find_device_by_node(child);
509 
510 			if (port_dev) {
511 				rc = ahci_platform_get_regulator(hpriv, port,
512 								&port_dev->dev);
513 				if (rc == -EPROBE_DEFER)
514 					goto err_out;
515 			}
516 #endif
517 
518 			rc = ahci_platform_get_phy(hpriv, port, dev, child);
519 			if (rc)
520 				goto err_out;
521 
522 			enabled_ports++;
523 		}
524 		if (!enabled_ports) {
525 			dev_warn(dev, "No port enabled\n");
526 			rc = -ENODEV;
527 			goto err_out;
528 		}
529 
530 		if (!hpriv->mask_port_map)
531 			hpriv->mask_port_map = mask_port_map;
532 	} else {
533 		/*
534 		 * If no sub-node was found, keep this for device tree
535 		 * compatibility
536 		 */
537 		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
538 		if (rc)
539 			goto err_out;
540 
541 		rc = ahci_platform_get_regulator(hpriv, 0, dev);
542 		if (rc == -EPROBE_DEFER)
543 			goto err_out;
544 	}
545 	pm_runtime_enable(dev);
546 	pm_runtime_get_sync(dev);
547 	hpriv->got_runtime_pm = true;
548 
549 	devres_remove_group(dev, NULL);
550 	return hpriv;
551 
552 err_out:
553 	devres_release_group(dev, NULL);
554 	return ERR_PTR(rc);
555 }
556 EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
557 
558 /**
559  * ahci_platform_init_host - Bring up an ahci-platform host
560  * @pdev: platform device pointer for the host
561  * @hpriv: ahci-host private data for the host
562  * @pi_template: template for the ata_port_info to use
563  * @sht: scsi_host_template to use when registering
564  *
565  * This function does all the usual steps needed to bring up an
566  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
567  * must be initialized / enabled before calling this.
568  *
569  * RETURNS:
570  * 0 on success otherwise a negative error code
571  */
572 int ahci_platform_init_host(struct platform_device *pdev,
573 			    struct ahci_host_priv *hpriv,
574 			    const struct ata_port_info *pi_template,
575 			    struct scsi_host_template *sht)
576 {
577 	struct device *dev = &pdev->dev;
578 	struct ata_port_info pi = *pi_template;
579 	const struct ata_port_info *ppi[] = { &pi, NULL };
580 	struct ata_host *host;
581 	int i, irq, n_ports, rc;
582 
583 	irq = platform_get_irq(pdev, 0);
584 	if (irq <= 0) {
585 		if (irq != -EPROBE_DEFER)
586 			dev_err(dev, "no irq\n");
587 		return irq;
588 	}
589 
590 	hpriv->irq = irq;
591 
592 	/* prepare host */
593 	pi.private_data = (void *)(unsigned long)hpriv->flags;
594 
595 	ahci_save_initial_config(dev, hpriv);
596 
597 	if (hpriv->cap & HOST_CAP_NCQ)
598 		pi.flags |= ATA_FLAG_NCQ;
599 
600 	if (hpriv->cap & HOST_CAP_PMP)
601 		pi.flags |= ATA_FLAG_PMP;
602 
603 	ahci_set_em_messages(hpriv, &pi);
604 
605 	/* CAP.NP sometimes indicate the index of the last enabled
606 	 * port, at other times, that of the last possible port, so
607 	 * determining the maximum port number requires looking at
608 	 * both CAP.NP and port_map.
609 	 */
610 	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
611 
612 	host = ata_host_alloc_pinfo(dev, ppi, n_ports);
613 	if (!host)
614 		return -ENOMEM;
615 
616 	host->private_data = hpriv;
617 
618 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
619 		host->flags |= ATA_HOST_PARALLEL_SCAN;
620 	else
621 		dev_info(dev, "SSS flag set, parallel bus scan disabled\n");
622 
623 	if (pi.flags & ATA_FLAG_EM)
624 		ahci_reset_em(host);
625 
626 	for (i = 0; i < host->n_ports; i++) {
627 		struct ata_port *ap = host->ports[i];
628 
629 		ata_port_desc(ap, "mmio %pR",
630 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
631 		ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
632 
633 		/* set enclosure management message type */
634 		if (ap->flags & ATA_FLAG_EM)
635 			ap->em_message_type = hpriv->em_msg_type;
636 
637 		/* disabled/not-implemented port */
638 		if (!(hpriv->port_map & (1 << i)))
639 			ap->ops = &ata_dummy_port_ops;
640 	}
641 
642 	if (hpriv->cap & HOST_CAP_64) {
643 		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
644 		if (rc) {
645 			rc = dma_coerce_mask_and_coherent(dev,
646 							  DMA_BIT_MASK(32));
647 			if (rc) {
648 				dev_err(dev, "Failed to enable 64-bit DMA.\n");
649 				return rc;
650 			}
651 			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
652 		}
653 	}
654 
655 	rc = ahci_reset_controller(host);
656 	if (rc)
657 		return rc;
658 
659 	ahci_init_controller(host);
660 	ahci_print_info(host, "platform");
661 
662 	return ahci_host_activate(host, sht);
663 }
664 EXPORT_SYMBOL_GPL(ahci_platform_init_host);
665 
666 static void ahci_host_stop(struct ata_host *host)
667 {
668 	struct ahci_host_priv *hpriv = host->private_data;
669 
670 	ahci_platform_disable_resources(hpriv);
671 }
672 
673 /**
674  * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports
675  * @pdev: platform device pointer for the host
676  *
677  * This function is called during system shutdown and performs the minimal
678  * deconfiguration required to ensure that an ahci_platform host cannot
679  * corrupt or otherwise interfere with a new kernel being started with kexec.
680  */
681 void ahci_platform_shutdown(struct platform_device *pdev)
682 {
683 	struct ata_host *host = platform_get_drvdata(pdev);
684 	struct ahci_host_priv *hpriv = host->private_data;
685 	void __iomem *mmio = hpriv->mmio;
686 	int i;
687 
688 	for (i = 0; i < host->n_ports; i++) {
689 		struct ata_port *ap = host->ports[i];
690 
691 		/* Disable port interrupts */
692 		if (ap->ops->freeze)
693 			ap->ops->freeze(ap);
694 
695 		/* Stop the port DMA engines */
696 		if (ap->ops->port_stop)
697 			ap->ops->port_stop(ap);
698 	}
699 
700 	/* Disable and clear host interrupts */
701 	writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL);
702 	readl(mmio + HOST_CTL); /* flush */
703 	writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT);
704 }
705 EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
706 
707 #ifdef CONFIG_PM_SLEEP
708 /**
709  * ahci_platform_suspend_host - Suspend an ahci-platform host
710  * @dev: device pointer for the host
711  *
712  * This function does all the usual steps needed to suspend an
713  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
714  * must be disabled after calling this.
715  *
716  * RETURNS:
717  * 0 on success otherwise a negative error code
718  */
719 int ahci_platform_suspend_host(struct device *dev)
720 {
721 	struct ata_host *host = dev_get_drvdata(dev);
722 	struct ahci_host_priv *hpriv = host->private_data;
723 	void __iomem *mmio = hpriv->mmio;
724 	u32 ctl;
725 
726 	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
727 		dev_err(dev, "firmware update required for suspend/resume\n");
728 		return -EIO;
729 	}
730 
731 	/*
732 	 * AHCI spec rev1.1 section 8.3.3:
733 	 * Software must disable interrupts prior to requesting a
734 	 * transition of the HBA to D3 state.
735 	 */
736 	ctl = readl(mmio + HOST_CTL);
737 	ctl &= ~HOST_IRQ_EN;
738 	writel(ctl, mmio + HOST_CTL);
739 	readl(mmio + HOST_CTL); /* flush */
740 
741 	return ata_host_suspend(host, PMSG_SUSPEND);
742 }
743 EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
744 
745 /**
746  * ahci_platform_resume_host - Resume an ahci-platform host
747  * @dev: device pointer for the host
748  *
749  * This function does all the usual steps needed to resume an ahci-platform
750  * host, note any necessary resources (ie clks, phys, etc.)  must be
751  * initialized / enabled before calling this.
752  *
753  * RETURNS:
754  * 0 on success otherwise a negative error code
755  */
756 int ahci_platform_resume_host(struct device *dev)
757 {
758 	struct ata_host *host = dev_get_drvdata(dev);
759 	int rc;
760 
761 	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
762 		rc = ahci_reset_controller(host);
763 		if (rc)
764 			return rc;
765 
766 		ahci_init_controller(host);
767 	}
768 
769 	ata_host_resume(host);
770 
771 	return 0;
772 }
773 EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
774 
775 /**
776  * ahci_platform_suspend - Suspend an ahci-platform device
777  * @dev: the platform device to suspend
778  *
779  * This function suspends the host associated with the device, followed by
780  * disabling all the resources of the device.
781  *
782  * RETURNS:
783  * 0 on success otherwise a negative error code
784  */
785 int ahci_platform_suspend(struct device *dev)
786 {
787 	struct ata_host *host = dev_get_drvdata(dev);
788 	struct ahci_host_priv *hpriv = host->private_data;
789 	int rc;
790 
791 	rc = ahci_platform_suspend_host(dev);
792 	if (rc)
793 		return rc;
794 
795 	ahci_platform_disable_resources(hpriv);
796 
797 	return 0;
798 }
799 EXPORT_SYMBOL_GPL(ahci_platform_suspend);
800 
801 /**
802  * ahci_platform_resume - Resume an ahci-platform device
803  * @dev: the platform device to resume
804  *
805  * This function enables all the resources of the device followed by
806  * resuming the host associated with the device.
807  *
808  * RETURNS:
809  * 0 on success otherwise a negative error code
810  */
811 int ahci_platform_resume(struct device *dev)
812 {
813 	struct ata_host *host = dev_get_drvdata(dev);
814 	struct ahci_host_priv *hpriv = host->private_data;
815 	int rc;
816 
817 	rc = ahci_platform_enable_resources(hpriv);
818 	if (rc)
819 		return rc;
820 
821 	rc = ahci_platform_resume_host(dev);
822 	if (rc)
823 		goto disable_resources;
824 
825 	/* We resumed so update PM runtime state */
826 	pm_runtime_disable(dev);
827 	pm_runtime_set_active(dev);
828 	pm_runtime_enable(dev);
829 
830 	return 0;
831 
832 disable_resources:
833 	ahci_platform_disable_resources(hpriv);
834 
835 	return rc;
836 }
837 EXPORT_SYMBOL_GPL(ahci_platform_resume);
838 #endif
839 
840 MODULE_DESCRIPTION("AHCI SATA platform library");
841 MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
842 MODULE_LICENSE("GPL");
843