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) Resets
251  * 3) Clocks (through ahci_platform_disable_clks)
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  * @flags: bitmap representing the resource to get
348  *
349  * This function allocates an ahci_host_priv struct, and gets the following
350  * resources, storing a reference to them inside the returned struct:
351  *
352  * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
353  * 2) regulator for controlling the targets power (optional)
354  * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
355  *    or for non devicetree enabled platforms a single clock
356  * 4) resets, if flags has AHCI_PLATFORM_GET_RESETS (optional)
357  * 5) phys (optional)
358  *
359  * RETURNS:
360  * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
361  */
362 struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
363 						   unsigned int flags)
364 {
365 	struct device *dev = &pdev->dev;
366 	struct ahci_host_priv *hpriv;
367 	struct clk *clk;
368 	struct device_node *child;
369 	int i, enabled_ports = 0, rc = -ENOMEM, child_nodes;
370 	u32 mask_port_map = 0;
371 
372 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
373 		return ERR_PTR(-ENOMEM);
374 
375 	hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
376 			     GFP_KERNEL);
377 	if (!hpriv)
378 		goto err_out;
379 
380 	devres_add(dev, hpriv);
381 
382 	hpriv->mmio = devm_ioremap_resource(dev,
383 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
384 	if (IS_ERR(hpriv->mmio)) {
385 		dev_err(dev, "no mmio space\n");
386 		rc = PTR_ERR(hpriv->mmio);
387 		goto err_out;
388 	}
389 
390 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
391 		/*
392 		 * For now we must use clk_get(dev, NULL) for the first clock,
393 		 * because some platforms (da850, spear13xx) are not yet
394 		 * converted to use devicetree for clocks.  For new platforms
395 		 * this is equivalent to of_clk_get(dev->of_node, 0).
396 		 */
397 		if (i == 0)
398 			clk = clk_get(dev, NULL);
399 		else
400 			clk = of_clk_get(dev->of_node, i);
401 
402 		if (IS_ERR(clk)) {
403 			rc = PTR_ERR(clk);
404 			if (rc == -EPROBE_DEFER)
405 				goto err_out;
406 			break;
407 		}
408 		hpriv->clks[i] = clk;
409 	}
410 
411 	if (flags & AHCI_PLATFORM_GET_RESETS) {
412 		hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
413 		if (IS_ERR(hpriv->rsts)) {
414 			rc = PTR_ERR(hpriv->rsts);
415 			goto err_out;
416 		}
417 	}
418 
419 	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
420 
421 	/*
422 	 * If no sub-node was found, we still need to set nports to
423 	 * one in order to be able to use the
424 	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
425 	 */
426 	if (!child_nodes)
427 		hpriv->nports = 1;
428 
429 	hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);
430 	if (!hpriv->phys) {
431 		rc = -ENOMEM;
432 		goto err_out;
433 	}
434 	/*
435 	 * We cannot use devm_ here, since ahci_platform_put_resources() uses
436 	 * target_pwrs after devm_ have freed memory
437 	 */
438 	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
439 	if (!hpriv->target_pwrs) {
440 		rc = -ENOMEM;
441 		goto err_out;
442 	}
443 
444 	if (child_nodes) {
445 		for_each_child_of_node(dev->of_node, child) {
446 			u32 port;
447 			struct platform_device *port_dev __maybe_unused;
448 
449 			if (!of_device_is_available(child))
450 				continue;
451 
452 			if (of_property_read_u32(child, "reg", &port)) {
453 				rc = -EINVAL;
454 				goto err_out;
455 			}
456 
457 			if (port >= hpriv->nports) {
458 				dev_warn(dev, "invalid port number %d\n", port);
459 				continue;
460 			}
461 			mask_port_map |= BIT(port);
462 
463 #ifdef CONFIG_OF_ADDRESS
464 			of_platform_device_create(child, NULL, NULL);
465 
466 			port_dev = of_find_device_by_node(child);
467 
468 			if (port_dev) {
469 				rc = ahci_platform_get_regulator(hpriv, port,
470 								&port_dev->dev);
471 				if (rc == -EPROBE_DEFER)
472 					goto err_out;
473 			}
474 #endif
475 
476 			rc = ahci_platform_get_phy(hpriv, port, dev, child);
477 			if (rc)
478 				goto err_out;
479 
480 			enabled_ports++;
481 		}
482 		if (!enabled_ports) {
483 			dev_warn(dev, "No port enabled\n");
484 			rc = -ENODEV;
485 			goto err_out;
486 		}
487 
488 		if (!hpriv->mask_port_map)
489 			hpriv->mask_port_map = mask_port_map;
490 	} else {
491 		/*
492 		 * If no sub-node was found, keep this for device tree
493 		 * compatibility
494 		 */
495 		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
496 		if (rc)
497 			goto err_out;
498 
499 		rc = ahci_platform_get_regulator(hpriv, 0, dev);
500 		if (rc == -EPROBE_DEFER)
501 			goto err_out;
502 	}
503 	pm_runtime_enable(dev);
504 	pm_runtime_get_sync(dev);
505 	hpriv->got_runtime_pm = true;
506 
507 	devres_remove_group(dev, NULL);
508 	return hpriv;
509 
510 err_out:
511 	devres_release_group(dev, NULL);
512 	return ERR_PTR(rc);
513 }
514 EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
515 
516 /**
517  * ahci_platform_init_host - Bring up an ahci-platform host
518  * @pdev: platform device pointer for the host
519  * @hpriv: ahci-host private data for the host
520  * @pi_template: template for the ata_port_info to use
521  * @sht: scsi_host_template to use when registering
522  *
523  * This function does all the usual steps needed to bring up an
524  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
525  * must be initialized / enabled before calling this.
526  *
527  * RETURNS:
528  * 0 on success otherwise a negative error code
529  */
530 int ahci_platform_init_host(struct platform_device *pdev,
531 			    struct ahci_host_priv *hpriv,
532 			    const struct ata_port_info *pi_template,
533 			    struct scsi_host_template *sht)
534 {
535 	struct device *dev = &pdev->dev;
536 	struct ata_port_info pi = *pi_template;
537 	const struct ata_port_info *ppi[] = { &pi, NULL };
538 	struct ata_host *host;
539 	int i, irq, n_ports, rc;
540 
541 	irq = platform_get_irq(pdev, 0);
542 	if (irq <= 0) {
543 		if (irq != -EPROBE_DEFER)
544 			dev_err(dev, "no irq\n");
545 		return irq;
546 	}
547 
548 	hpriv->irq = irq;
549 
550 	/* prepare host */
551 	pi.private_data = (void *)(unsigned long)hpriv->flags;
552 
553 	ahci_save_initial_config(dev, hpriv);
554 
555 	if (hpriv->cap & HOST_CAP_NCQ)
556 		pi.flags |= ATA_FLAG_NCQ;
557 
558 	if (hpriv->cap & HOST_CAP_PMP)
559 		pi.flags |= ATA_FLAG_PMP;
560 
561 	ahci_set_em_messages(hpriv, &pi);
562 
563 	/* CAP.NP sometimes indicate the index of the last enabled
564 	 * port, at other times, that of the last possible port, so
565 	 * determining the maximum port number requires looking at
566 	 * both CAP.NP and port_map.
567 	 */
568 	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
569 
570 	host = ata_host_alloc_pinfo(dev, ppi, n_ports);
571 	if (!host)
572 		return -ENOMEM;
573 
574 	host->private_data = hpriv;
575 
576 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
577 		host->flags |= ATA_HOST_PARALLEL_SCAN;
578 	else
579 		dev_info(dev, "SSS flag set, parallel bus scan disabled\n");
580 
581 	if (pi.flags & ATA_FLAG_EM)
582 		ahci_reset_em(host);
583 
584 	for (i = 0; i < host->n_ports; i++) {
585 		struct ata_port *ap = host->ports[i];
586 
587 		ata_port_desc(ap, "mmio %pR",
588 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
589 		ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
590 
591 		/* set enclosure management message type */
592 		if (ap->flags & ATA_FLAG_EM)
593 			ap->em_message_type = hpriv->em_msg_type;
594 
595 		/* disabled/not-implemented port */
596 		if (!(hpriv->port_map & (1 << i)))
597 			ap->ops = &ata_dummy_port_ops;
598 	}
599 
600 	if (hpriv->cap & HOST_CAP_64) {
601 		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
602 		if (rc) {
603 			rc = dma_coerce_mask_and_coherent(dev,
604 							  DMA_BIT_MASK(32));
605 			if (rc) {
606 				dev_err(dev, "Failed to enable 64-bit DMA.\n");
607 				return rc;
608 			}
609 			dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
610 		}
611 	}
612 
613 	rc = ahci_reset_controller(host);
614 	if (rc)
615 		return rc;
616 
617 	ahci_init_controller(host);
618 	ahci_print_info(host, "platform");
619 
620 	return ahci_host_activate(host, sht);
621 }
622 EXPORT_SYMBOL_GPL(ahci_platform_init_host);
623 
624 static void ahci_host_stop(struct ata_host *host)
625 {
626 	struct ahci_host_priv *hpriv = host->private_data;
627 
628 	ahci_platform_disable_resources(hpriv);
629 }
630 
631 /**
632  * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports
633  * @pdev: platform device pointer for the host
634  *
635  * This function is called during system shutdown and performs the minimal
636  * deconfiguration required to ensure that an ahci_platform host cannot
637  * corrupt or otherwise interfere with a new kernel being started with kexec.
638  */
639 void ahci_platform_shutdown(struct platform_device *pdev)
640 {
641 	struct ata_host *host = platform_get_drvdata(pdev);
642 	struct ahci_host_priv *hpriv = host->private_data;
643 	void __iomem *mmio = hpriv->mmio;
644 	int i;
645 
646 	for (i = 0; i < host->n_ports; i++) {
647 		struct ata_port *ap = host->ports[i];
648 
649 		/* Disable port interrupts */
650 		if (ap->ops->freeze)
651 			ap->ops->freeze(ap);
652 
653 		/* Stop the port DMA engines */
654 		if (ap->ops->port_stop)
655 			ap->ops->port_stop(ap);
656 	}
657 
658 	/* Disable and clear host interrupts */
659 	writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL);
660 	readl(mmio + HOST_CTL); /* flush */
661 	writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT);
662 }
663 EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
664 
665 #ifdef CONFIG_PM_SLEEP
666 /**
667  * ahci_platform_suspend_host - Suspend an ahci-platform host
668  * @dev: device pointer for the host
669  *
670  * This function does all the usual steps needed to suspend an
671  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
672  * must be disabled after calling this.
673  *
674  * RETURNS:
675  * 0 on success otherwise a negative error code
676  */
677 int ahci_platform_suspend_host(struct device *dev)
678 {
679 	struct ata_host *host = dev_get_drvdata(dev);
680 	struct ahci_host_priv *hpriv = host->private_data;
681 	void __iomem *mmio = hpriv->mmio;
682 	u32 ctl;
683 
684 	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
685 		dev_err(dev, "firmware update required for suspend/resume\n");
686 		return -EIO;
687 	}
688 
689 	/*
690 	 * AHCI spec rev1.1 section 8.3.3:
691 	 * Software must disable interrupts prior to requesting a
692 	 * transition of the HBA to D3 state.
693 	 */
694 	ctl = readl(mmio + HOST_CTL);
695 	ctl &= ~HOST_IRQ_EN;
696 	writel(ctl, mmio + HOST_CTL);
697 	readl(mmio + HOST_CTL); /* flush */
698 
699 	return ata_host_suspend(host, PMSG_SUSPEND);
700 }
701 EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
702 
703 /**
704  * ahci_platform_resume_host - Resume an ahci-platform host
705  * @dev: device pointer for the host
706  *
707  * This function does all the usual steps needed to resume an ahci-platform
708  * host, note any necessary resources (ie clks, phys, etc.)  must be
709  * initialized / enabled before calling this.
710  *
711  * RETURNS:
712  * 0 on success otherwise a negative error code
713  */
714 int ahci_platform_resume_host(struct device *dev)
715 {
716 	struct ata_host *host = dev_get_drvdata(dev);
717 	int rc;
718 
719 	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
720 		rc = ahci_reset_controller(host);
721 		if (rc)
722 			return rc;
723 
724 		ahci_init_controller(host);
725 	}
726 
727 	ata_host_resume(host);
728 
729 	return 0;
730 }
731 EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
732 
733 /**
734  * ahci_platform_suspend - Suspend an ahci-platform device
735  * @dev: the platform device to suspend
736  *
737  * This function suspends the host associated with the device, followed by
738  * disabling all the resources of the device.
739  *
740  * RETURNS:
741  * 0 on success otherwise a negative error code
742  */
743 int ahci_platform_suspend(struct device *dev)
744 {
745 	struct ata_host *host = dev_get_drvdata(dev);
746 	struct ahci_host_priv *hpriv = host->private_data;
747 	int rc;
748 
749 	rc = ahci_platform_suspend_host(dev);
750 	if (rc)
751 		return rc;
752 
753 	ahci_platform_disable_resources(hpriv);
754 
755 	return 0;
756 }
757 EXPORT_SYMBOL_GPL(ahci_platform_suspend);
758 
759 /**
760  * ahci_platform_resume - Resume an ahci-platform device
761  * @dev: the platform device to resume
762  *
763  * This function enables all the resources of the device followed by
764  * resuming the host associated with the device.
765  *
766  * RETURNS:
767  * 0 on success otherwise a negative error code
768  */
769 int ahci_platform_resume(struct device *dev)
770 {
771 	struct ata_host *host = dev_get_drvdata(dev);
772 	struct ahci_host_priv *hpriv = host->private_data;
773 	int rc;
774 
775 	rc = ahci_platform_enable_resources(hpriv);
776 	if (rc)
777 		return rc;
778 
779 	rc = ahci_platform_resume_host(dev);
780 	if (rc)
781 		goto disable_resources;
782 
783 	/* We resumed so update PM runtime state */
784 	pm_runtime_disable(dev);
785 	pm_runtime_set_active(dev);
786 	pm_runtime_enable(dev);
787 
788 	return 0;
789 
790 disable_resources:
791 	ahci_platform_disable_resources(hpriv);
792 
793 	return rc;
794 }
795 EXPORT_SYMBOL_GPL(ahci_platform_resume);
796 #endif
797 
798 MODULE_DESCRIPTION("AHCI SATA platform library");
799 MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
800 MODULE_LICENSE("GPL");
801