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
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 	for (i = 0; i < hpriv->nports; i++) {
155 		if (!hpriv->target_pwrs[i])
156 			continue;
157 
158 		rc = regulator_enable(hpriv->target_pwrs[i]);
159 		if (rc)
160 			goto disable_target_pwrs;
161 	}
162 
163 	return 0;
164 
165 disable_target_pwrs:
166 	while (--i >= 0)
167 		if (hpriv->target_pwrs[i])
168 			regulator_disable(hpriv->target_pwrs[i]);
169 
170 	return rc;
171 }
172 EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
173 
174 /**
175  * ahci_platform_disable_regulators - Disable regulators
176  * @hpriv: host private area to store config values
177  *
178  * This function disables all regulators found in hpriv->target_pwrs.
179  */
180 void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
181 {
182 	int i;
183 
184 	for (i = 0; i < hpriv->nports; i++) {
185 		if (!hpriv->target_pwrs[i])
186 			continue;
187 		regulator_disable(hpriv->target_pwrs[i]);
188 	}
189 }
190 EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
191 /**
192  * ahci_platform_enable_resources - Enable platform resources
193  * @hpriv: host private area to store config values
194  *
195  * This function enables all ahci_platform managed resources in the
196  * following order:
197  * 1) Regulator
198  * 2) Clocks (through ahci_platform_enable_clks)
199  * 3) Resets
200  * 4) Phys
201  *
202  * If resource enabling fails at any point the previous enabled resources
203  * are disabled in reverse order.
204  *
205  * RETURNS:
206  * 0 on success otherwise a negative error code
207  */
208 int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
209 {
210 	int rc;
211 
212 	rc = ahci_platform_enable_regulators(hpriv);
213 	if (rc)
214 		return rc;
215 
216 	rc = ahci_platform_enable_clks(hpriv);
217 	if (rc)
218 		goto disable_regulator;
219 
220 	rc = reset_control_deassert(hpriv->rsts);
221 	if (rc)
222 		goto disable_clks;
223 
224 	rc = ahci_platform_enable_phys(hpriv);
225 	if (rc)
226 		goto disable_resets;
227 
228 	return 0;
229 
230 disable_resets:
231 	reset_control_assert(hpriv->rsts);
232 
233 disable_clks:
234 	ahci_platform_disable_clks(hpriv);
235 
236 disable_regulator:
237 	ahci_platform_disable_regulators(hpriv);
238 
239 	return rc;
240 }
241 EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
242 
243 /**
244  * ahci_platform_disable_resources - Disable platform resources
245  * @hpriv: host private area to store config values
246  *
247  * This function disables all ahci_platform managed resources in the
248  * following order:
249  * 1) Phys
250  * 2) Clocks (through ahci_platform_disable_clks)
251  * 3) Resets
252  * 4) Regulator
253  */
254 void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
255 {
256 	ahci_platform_disable_phys(hpriv);
257 
258 	reset_control_assert(hpriv->rsts);
259 
260 	ahci_platform_disable_clks(hpriv);
261 
262 	ahci_platform_disable_regulators(hpriv);
263 }
264 EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
265 
266 static void ahci_platform_put_resources(struct device *dev, void *res)
267 {
268 	struct ahci_host_priv *hpriv = res;
269 	int c;
270 
271 	if (hpriv->got_runtime_pm) {
272 		pm_runtime_put_sync(dev);
273 		pm_runtime_disable(dev);
274 	}
275 
276 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
277 		clk_put(hpriv->clks[c]);
278 	/*
279 	 * The regulators are tied to child node device and not to the
280 	 * SATA device itself. So we can't use devm for automatically
281 	 * releasing them. We have to do it manually here.
282 	 */
283 	for (c = 0; c < hpriv->nports; c++)
284 		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
285 			regulator_put(hpriv->target_pwrs[c]);
286 
287 	kfree(hpriv->target_pwrs);
288 }
289 
290 static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
291 				struct device *dev, struct device_node *node)
292 {
293 	int rc;
294 
295 	hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
296 
297 	if (!IS_ERR(hpriv->phys[port]))
298 		return 0;
299 
300 	rc = PTR_ERR(hpriv->phys[port]);
301 	switch (rc) {
302 	case -ENOSYS:
303 		/* No PHY support. Check if PHY is required. */
304 		if (of_find_property(node, "phys", NULL)) {
305 			dev_err(dev,
306 				"couldn't get PHY in node %s: ENOSYS\n",
307 				node->name);
308 			break;
309 		}
310 		/* fall through */
311 	case -ENODEV:
312 		/* continue normally */
313 		hpriv->phys[port] = NULL;
314 		rc = 0;
315 		break;
316 
317 	default:
318 		dev_err(dev,
319 			"couldn't get PHY in node %s: %d\n",
320 			node->name, rc);
321 
322 		break;
323 	}
324 
325 	return rc;
326 }
327 
328 static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
329 				struct device *dev)
330 {
331 	struct regulator *target_pwr;
332 	int rc = 0;
333 
334 	target_pwr = regulator_get_optional(dev, "target");
335 
336 	if (!IS_ERR(target_pwr))
337 		hpriv->target_pwrs[port] = target_pwr;
338 	else
339 		rc = PTR_ERR(target_pwr);
340 
341 	return rc;
342 }
343 
344 /**
345  * ahci_platform_get_resources - Get platform resources
346  * @pdev: platform device to get resources for
347  *
348  * This function allocates an ahci_host_priv struct, and gets the following
349  * resources, storing a reference to them inside the returned struct:
350  *
351  * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
352  * 2) regulator for controlling the targets power (optional)
353  * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
354  *    or for non devicetree enabled platforms a single clock
355  * 4) phys (optional)
356  *
357  * RETURNS:
358  * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
359  */
360 struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
361 {
362 	struct device *dev = &pdev->dev;
363 	struct ahci_host_priv *hpriv;
364 	struct clk *clk;
365 	struct device_node *child;
366 	int i, sz, enabled_ports = 0, rc = -ENOMEM, child_nodes;
367 	u32 mask_port_map = 0;
368 
369 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
370 		return ERR_PTR(-ENOMEM);
371 
372 	hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
373 			     GFP_KERNEL);
374 	if (!hpriv)
375 		goto err_out;
376 
377 	devres_add(dev, hpriv);
378 
379 	hpriv->mmio = devm_ioremap_resource(dev,
380 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
381 	if (IS_ERR(hpriv->mmio)) {
382 		dev_err(dev, "no mmio space\n");
383 		rc = PTR_ERR(hpriv->mmio);
384 		goto err_out;
385 	}
386 
387 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
388 		/*
389 		 * For now we must use clk_get(dev, NULL) for the first clock,
390 		 * because some platforms (da850, spear13xx) are not yet
391 		 * converted to use devicetree for clocks.  For new platforms
392 		 * this is equivalent to of_clk_get(dev->of_node, 0).
393 		 */
394 		if (i == 0)
395 			clk = clk_get(dev, NULL);
396 		else
397 			clk = of_clk_get(dev->of_node, i);
398 
399 		if (IS_ERR(clk)) {
400 			rc = PTR_ERR(clk);
401 			if (rc == -EPROBE_DEFER)
402 				goto err_out;
403 			break;
404 		}
405 		hpriv->clks[i] = clk;
406 	}
407 
408 	hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
409 	if (IS_ERR(hpriv->rsts)) {
410 		rc = PTR_ERR(hpriv->rsts);
411 		goto err_out;
412 	}
413 
414 	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
415 
416 	/*
417 	 * If no sub-node was found, we still need to set nports to
418 	 * one in order to be able to use the
419 	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
420 	 */
421 	if (!child_nodes)
422 		hpriv->nports = 1;
423 
424 	sz = hpriv->nports * sizeof(*hpriv->phys);
425 	hpriv->phys = devm_kzalloc(dev, sz, GFP_KERNEL);
426 	if (!hpriv->phys) {
427 		rc = -ENOMEM;
428 		goto err_out;
429 	}
430 	sz = hpriv->nports * sizeof(*hpriv->target_pwrs);
431 	hpriv->target_pwrs = kzalloc(sz, GFP_KERNEL);
432 	if (!hpriv->target_pwrs) {
433 		rc = -ENOMEM;
434 		goto err_out;
435 	}
436 
437 	if (child_nodes) {
438 		for_each_child_of_node(dev->of_node, child) {
439 			u32 port;
440 			struct platform_device *port_dev __maybe_unused;
441 
442 			if (!of_device_is_available(child))
443 				continue;
444 
445 			if (of_property_read_u32(child, "reg", &port)) {
446 				rc = -EINVAL;
447 				goto err_out;
448 			}
449 
450 			if (port >= hpriv->nports) {
451 				dev_warn(dev, "invalid port number %d\n", port);
452 				continue;
453 			}
454 			mask_port_map |= BIT(port);
455 
456 #ifdef CONFIG_OF_ADDRESS
457 			of_platform_device_create(child, NULL, NULL);
458 
459 			port_dev = of_find_device_by_node(child);
460 
461 			if (port_dev) {
462 				rc = ahci_platform_get_regulator(hpriv, port,
463 								&port_dev->dev);
464 				if (rc == -EPROBE_DEFER)
465 					goto err_out;
466 			}
467 #endif
468 
469 			rc = ahci_platform_get_phy(hpriv, port, dev, child);
470 			if (rc)
471 				goto err_out;
472 
473 			enabled_ports++;
474 		}
475 		if (!enabled_ports) {
476 			dev_warn(dev, "No port enabled\n");
477 			rc = -ENODEV;
478 			goto err_out;
479 		}
480 
481 		if (!hpriv->mask_port_map)
482 			hpriv->mask_port_map = mask_port_map;
483 	} else {
484 		/*
485 		 * If no sub-node was found, keep this for device tree
486 		 * compatibility
487 		 */
488 		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
489 		if (rc)
490 			goto err_out;
491 
492 		rc = ahci_platform_get_regulator(hpriv, 0, dev);
493 		if (rc == -EPROBE_DEFER)
494 			goto err_out;
495 	}
496 	pm_runtime_enable(dev);
497 	pm_runtime_get_sync(dev);
498 	hpriv->got_runtime_pm = true;
499 
500 	devres_remove_group(dev, NULL);
501 	return hpriv;
502 
503 err_out:
504 	devres_release_group(dev, NULL);
505 	return ERR_PTR(rc);
506 }
507 EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
508 
509 /**
510  * ahci_platform_init_host - Bring up an ahci-platform host
511  * @pdev: platform device pointer for the host
512  * @hpriv: ahci-host private data for the host
513  * @pi_template: template for the ata_port_info to use
514  * @sht: scsi_host_template to use when registering
515  *
516  * This function does all the usual steps needed to bring up an
517  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
518  * must be initialized / enabled before calling this.
519  *
520  * RETURNS:
521  * 0 on success otherwise a negative error code
522  */
523 int ahci_platform_init_host(struct platform_device *pdev,
524 			    struct ahci_host_priv *hpriv,
525 			    const struct ata_port_info *pi_template,
526 			    struct scsi_host_template *sht)
527 {
528 	struct device *dev = &pdev->dev;
529 	struct ata_port_info pi = *pi_template;
530 	const struct ata_port_info *ppi[] = { &pi, NULL };
531 	struct ata_host *host;
532 	int i, irq, n_ports, rc;
533 
534 	irq = platform_get_irq(pdev, 0);
535 	if (irq <= 0) {
536 		if (irq != -EPROBE_DEFER)
537 			dev_err(dev, "no irq\n");
538 		return irq;
539 	}
540 
541 	hpriv->irq = irq;
542 
543 	/* prepare host */
544 	pi.private_data = (void *)(unsigned long)hpriv->flags;
545 
546 	ahci_save_initial_config(dev, hpriv);
547 
548 	if (hpriv->cap & HOST_CAP_NCQ)
549 		pi.flags |= ATA_FLAG_NCQ;
550 
551 	if (hpriv->cap & HOST_CAP_PMP)
552 		pi.flags |= ATA_FLAG_PMP;
553 
554 	ahci_set_em_messages(hpriv, &pi);
555 
556 	/* CAP.NP sometimes indicate the index of the last enabled
557 	 * port, at other times, that of the last possible port, so
558 	 * determining the maximum port number requires looking at
559 	 * both CAP.NP and port_map.
560 	 */
561 	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
562 
563 	host = ata_host_alloc_pinfo(dev, ppi, n_ports);
564 	if (!host)
565 		return -ENOMEM;
566 
567 	host->private_data = hpriv;
568 
569 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
570 		host->flags |= ATA_HOST_PARALLEL_SCAN;
571 	else
572 		dev_info(dev, "SSS flag set, parallel bus scan disabled\n");
573 
574 	if (pi.flags & ATA_FLAG_EM)
575 		ahci_reset_em(host);
576 
577 	for (i = 0; i < host->n_ports; i++) {
578 		struct ata_port *ap = host->ports[i];
579 
580 		ata_port_desc(ap, "mmio %pR",
581 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
582 		ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
583 
584 		/* set enclosure management message type */
585 		if (ap->flags & ATA_FLAG_EM)
586 			ap->em_message_type = hpriv->em_msg_type;
587 
588 		/* disabled/not-implemented port */
589 		if (!(hpriv->port_map & (1 << i)))
590 			ap->ops = &ata_dummy_port_ops;
591 	}
592 
593 	if (hpriv->cap & HOST_CAP_64) {
594 		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
595 		if (rc) {
596 			rc = dma_coerce_mask_and_coherent(dev,
597 							  DMA_BIT_MASK(32));
598 			if (rc) {
599 				dev_err(dev, "Failed to enable 64-bit DMA.\n");
600 				return rc;
601 			}
602 			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
603 		}
604 	}
605 
606 	rc = ahci_reset_controller(host);
607 	if (rc)
608 		return rc;
609 
610 	ahci_init_controller(host);
611 	ahci_print_info(host, "platform");
612 
613 	return ahci_host_activate(host, sht);
614 }
615 EXPORT_SYMBOL_GPL(ahci_platform_init_host);
616 
617 static void ahci_host_stop(struct ata_host *host)
618 {
619 	struct ahci_host_priv *hpriv = host->private_data;
620 
621 	ahci_platform_disable_resources(hpriv);
622 }
623 
624 /**
625  * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports
626  * @dev: platform device pointer for the host
627  *
628  * This function is called during system shutdown and performs the minimal
629  * deconfiguration required to ensure that an ahci_platform host cannot
630  * corrupt or otherwise interfere with a new kernel being started with kexec.
631  */
632 void ahci_platform_shutdown(struct platform_device *pdev)
633 {
634 	struct ata_host *host = platform_get_drvdata(pdev);
635 	struct ahci_host_priv *hpriv = host->private_data;
636 	void __iomem *mmio = hpriv->mmio;
637 	int i;
638 
639 	for (i = 0; i < host->n_ports; i++) {
640 		struct ata_port *ap = host->ports[i];
641 
642 		/* Disable port interrupts */
643 		if (ap->ops->freeze)
644 			ap->ops->freeze(ap);
645 
646 		/* Stop the port DMA engines */
647 		if (ap->ops->port_stop)
648 			ap->ops->port_stop(ap);
649 	}
650 
651 	/* Disable and clear host interrupts */
652 	writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL);
653 	readl(mmio + HOST_CTL); /* flush */
654 	writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT);
655 }
656 EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
657 
658 #ifdef CONFIG_PM_SLEEP
659 /**
660  * ahci_platform_suspend_host - Suspend an ahci-platform host
661  * @dev: device pointer for the host
662  *
663  * This function does all the usual steps needed to suspend an
664  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
665  * must be disabled after calling this.
666  *
667  * RETURNS:
668  * 0 on success otherwise a negative error code
669  */
670 int ahci_platform_suspend_host(struct device *dev)
671 {
672 	struct ata_host *host = dev_get_drvdata(dev);
673 	struct ahci_host_priv *hpriv = host->private_data;
674 	void __iomem *mmio = hpriv->mmio;
675 	u32 ctl;
676 
677 	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
678 		dev_err(dev, "firmware update required for suspend/resume\n");
679 		return -EIO;
680 	}
681 
682 	/*
683 	 * AHCI spec rev1.1 section 8.3.3:
684 	 * Software must disable interrupts prior to requesting a
685 	 * transition of the HBA to D3 state.
686 	 */
687 	ctl = readl(mmio + HOST_CTL);
688 	ctl &= ~HOST_IRQ_EN;
689 	writel(ctl, mmio + HOST_CTL);
690 	readl(mmio + HOST_CTL); /* flush */
691 
692 	return ata_host_suspend(host, PMSG_SUSPEND);
693 }
694 EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
695 
696 /**
697  * ahci_platform_resume_host - Resume an ahci-platform host
698  * @dev: device pointer for the host
699  *
700  * This function does all the usual steps needed to resume an ahci-platform
701  * host, note any necessary resources (ie clks, phys, etc.)  must be
702  * initialized / enabled before calling this.
703  *
704  * RETURNS:
705  * 0 on success otherwise a negative error code
706  */
707 int ahci_platform_resume_host(struct device *dev)
708 {
709 	struct ata_host *host = dev_get_drvdata(dev);
710 	int rc;
711 
712 	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
713 		rc = ahci_reset_controller(host);
714 		if (rc)
715 			return rc;
716 
717 		ahci_init_controller(host);
718 	}
719 
720 	ata_host_resume(host);
721 
722 	return 0;
723 }
724 EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
725 
726 /**
727  * ahci_platform_suspend - Suspend an ahci-platform device
728  * @dev: the platform device to suspend
729  *
730  * This function suspends the host associated with the device, followed by
731  * disabling all the resources of the device.
732  *
733  * RETURNS:
734  * 0 on success otherwise a negative error code
735  */
736 int ahci_platform_suspend(struct device *dev)
737 {
738 	struct ata_host *host = dev_get_drvdata(dev);
739 	struct ahci_host_priv *hpriv = host->private_data;
740 	int rc;
741 
742 	rc = ahci_platform_suspend_host(dev);
743 	if (rc)
744 		return rc;
745 
746 	ahci_platform_disable_resources(hpriv);
747 
748 	return 0;
749 }
750 EXPORT_SYMBOL_GPL(ahci_platform_suspend);
751 
752 /**
753  * ahci_platform_resume - Resume an ahci-platform device
754  * @dev: the platform device to resume
755  *
756  * This function enables all the resources of the device followed by
757  * resuming the host associated with the device.
758  *
759  * RETURNS:
760  * 0 on success otherwise a negative error code
761  */
762 int ahci_platform_resume(struct device *dev)
763 {
764 	struct ata_host *host = dev_get_drvdata(dev);
765 	struct ahci_host_priv *hpriv = host->private_data;
766 	int rc;
767 
768 	rc = ahci_platform_enable_resources(hpriv);
769 	if (rc)
770 		return rc;
771 
772 	rc = ahci_platform_resume_host(dev);
773 	if (rc)
774 		goto disable_resources;
775 
776 	/* We resumed so update PM runtime state */
777 	pm_runtime_disable(dev);
778 	pm_runtime_set_active(dev);
779 	pm_runtime_enable(dev);
780 
781 	return 0;
782 
783 disable_resources:
784 	ahci_platform_disable_resources(hpriv);
785 
786 	return rc;
787 }
788 EXPORT_SYMBOL_GPL(ahci_platform_resume);
789 #endif
790 
791 MODULE_DESCRIPTION("AHCI SATA platform library");
792 MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
793 MODULE_LICENSE("GPL");
794