xref: /linux/drivers/ata/libahci_platform.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AHCI SATA platform library
4  *
5  * Copyright 2004-2005  Red Hat, Inc.
6  *   Jeff Garzik <jgarzik@pobox.com>
7  * Copyright 2010  MontaVista Software, LLC.
8  *   Anton Vorontsov <avorontsov@ru.mvista.com>
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/kernel.h>
13 #include <linux/gfp.h>
14 #include <linux/module.h>
15 #include <linux/pm.h>
16 #include <linux/interrupt.h>
17 #include <linux/device.h>
18 #include <linux/platform_device.h>
19 #include <linux/libata.h>
20 #include <linux/ahci_platform.h>
21 #include <linux/phy/phy.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/of_platform.h>
24 #include <linux/reset.h>
25 #include "ahci.h"
26 
27 static void ahci_host_stop(struct ata_host *host);
28 
29 struct ata_port_operations ahci_platform_ops = {
30 	.inherits	= &ahci_ops,
31 	.host_stop	= ahci_host_stop,
32 };
33 EXPORT_SYMBOL_GPL(ahci_platform_ops);
34 
35 /**
36  * ahci_platform_enable_phys - Enable PHYs
37  * @hpriv: host private area to store config values
38  *
39  * This function enables all the PHYs found in hpriv->phys, if any.
40  * If a PHY fails to be enabled, it disables all the PHYs already
41  * enabled in reverse order and returns an error.
42  *
43  * RETURNS:
44  * 0 on success otherwise a negative error code
45  */
46 int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
47 {
48 	int rc, i;
49 
50 	for (i = 0; i < hpriv->nports; i++) {
51 		rc = phy_init(hpriv->phys[i]);
52 		if (rc)
53 			goto disable_phys;
54 
55 		rc = phy_set_mode(hpriv->phys[i], PHY_MODE_SATA);
56 		if (rc) {
57 			phy_exit(hpriv->phys[i]);
58 			goto disable_phys;
59 		}
60 
61 		rc = phy_power_on(hpriv->phys[i]);
62 		if (rc) {
63 			phy_exit(hpriv->phys[i]);
64 			goto disable_phys;
65 		}
66 	}
67 
68 	return 0;
69 
70 disable_phys:
71 	while (--i >= 0) {
72 		phy_power_off(hpriv->phys[i]);
73 		phy_exit(hpriv->phys[i]);
74 	}
75 	return rc;
76 }
77 EXPORT_SYMBOL_GPL(ahci_platform_enable_phys);
78 
79 /**
80  * ahci_platform_disable_phys - Disable PHYs
81  * @hpriv: host private area to store config values
82  *
83  * This function disables all PHYs found in hpriv->phys.
84  */
85 void ahci_platform_disable_phys(struct ahci_host_priv *hpriv)
86 {
87 	int i;
88 
89 	for (i = 0; i < hpriv->nports; i++) {
90 		phy_power_off(hpriv->phys[i]);
91 		phy_exit(hpriv->phys[i]);
92 	}
93 }
94 EXPORT_SYMBOL_GPL(ahci_platform_disable_phys);
95 
96 /**
97  * ahci_platform_enable_clks - Enable platform clocks
98  * @hpriv: host private area to store config values
99  *
100  * This function enables all the clks found in hpriv->clks, starting at
101  * index 0. If any clk fails to enable it disables all the clks already
102  * enabled in reverse order, and then returns an error.
103  *
104  * RETURNS:
105  * 0 on success otherwise a negative error code
106  */
107 int ahci_platform_enable_clks(struct ahci_host_priv *hpriv)
108 {
109 	int c, rc;
110 
111 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++) {
112 		rc = clk_prepare_enable(hpriv->clks[c]);
113 		if (rc)
114 			goto disable_unprepare_clk;
115 	}
116 	return 0;
117 
118 disable_unprepare_clk:
119 	while (--c >= 0)
120 		clk_disable_unprepare(hpriv->clks[c]);
121 	return rc;
122 }
123 EXPORT_SYMBOL_GPL(ahci_platform_enable_clks);
124 
125 /**
126  * ahci_platform_disable_clks - Disable platform clocks
127  * @hpriv: host private area to store config values
128  *
129  * This function disables all the clks found in hpriv->clks, in reverse
130  * order of ahci_platform_enable_clks (starting at the end of the array).
131  */
132 void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
133 {
134 	int c;
135 
136 	for (c = AHCI_MAX_CLKS - 1; c >= 0; c--)
137 		if (hpriv->clks[c])
138 			clk_disable_unprepare(hpriv->clks[c]);
139 }
140 EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
141 
142 /**
143  * ahci_platform_enable_regulators - Enable regulators
144  * @hpriv: host private area to store config values
145  *
146  * This function enables all the regulators found in controller and
147  * hpriv->target_pwrs, if any.  If a regulator fails to be enabled, it
148  * disables all the regulators already enabled in reverse order and
149  * returns an error.
150  *
151  * RETURNS:
152  * 0 on success otherwise a negative error code
153  */
154 int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
155 {
156 	int rc, i;
157 
158 	rc = regulator_enable(hpriv->ahci_regulator);
159 	if (rc)
160 		return rc;
161 
162 	rc = regulator_enable(hpriv->phy_regulator);
163 	if (rc)
164 		goto disable_ahci_pwrs;
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 	regulator_disable(hpriv->phy_regulator);
183 disable_ahci_pwrs:
184 	regulator_disable(hpriv->ahci_regulator);
185 	return rc;
186 }
187 EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
188 
189 /**
190  * ahci_platform_disable_regulators - Disable regulators
191  * @hpriv: host private area to store config values
192  *
193  * This function disables all regulators found in hpriv->target_pwrs and
194  * AHCI controller.
195  */
196 void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
197 {
198 	int i;
199 
200 	for (i = 0; i < hpriv->nports; i++) {
201 		if (!hpriv->target_pwrs[i])
202 			continue;
203 		regulator_disable(hpriv->target_pwrs[i]);
204 	}
205 
206 	regulator_disable(hpriv->ahci_regulator);
207 	regulator_disable(hpriv->phy_regulator);
208 }
209 EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
210 /**
211  * ahci_platform_enable_resources - Enable platform resources
212  * @hpriv: host private area to store config values
213  *
214  * This function enables all ahci_platform managed resources in the
215  * following order:
216  * 1) Regulator
217  * 2) Clocks (through ahci_platform_enable_clks)
218  * 3) Resets
219  * 4) Phys
220  *
221  * If resource enabling fails at any point the previous enabled resources
222  * are disabled in reverse order.
223  *
224  * RETURNS:
225  * 0 on success otherwise a negative error code
226  */
227 int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
228 {
229 	int rc;
230 
231 	rc = ahci_platform_enable_regulators(hpriv);
232 	if (rc)
233 		return rc;
234 
235 	rc = ahci_platform_enable_clks(hpriv);
236 	if (rc)
237 		goto disable_regulator;
238 
239 	rc = reset_control_deassert(hpriv->rsts);
240 	if (rc)
241 		goto disable_clks;
242 
243 	rc = ahci_platform_enable_phys(hpriv);
244 	if (rc)
245 		goto disable_resets;
246 
247 	return 0;
248 
249 disable_resets:
250 	reset_control_assert(hpriv->rsts);
251 
252 disable_clks:
253 	ahci_platform_disable_clks(hpriv);
254 
255 disable_regulator:
256 	ahci_platform_disable_regulators(hpriv);
257 
258 	return rc;
259 }
260 EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
261 
262 /**
263  * ahci_platform_disable_resources - Disable platform resources
264  * @hpriv: host private area to store config values
265  *
266  * This function disables all ahci_platform managed resources in the
267  * following order:
268  * 1) Phys
269  * 2) Resets
270  * 3) Clocks (through ahci_platform_disable_clks)
271  * 4) Regulator
272  */
273 void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
274 {
275 	ahci_platform_disable_phys(hpriv);
276 
277 	reset_control_assert(hpriv->rsts);
278 
279 	ahci_platform_disable_clks(hpriv);
280 
281 	ahci_platform_disable_regulators(hpriv);
282 }
283 EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
284 
285 static void ahci_platform_put_resources(struct device *dev, void *res)
286 {
287 	struct ahci_host_priv *hpriv = res;
288 	int c;
289 
290 	if (hpriv->got_runtime_pm) {
291 		pm_runtime_put_sync(dev);
292 		pm_runtime_disable(dev);
293 	}
294 
295 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
296 		clk_put(hpriv->clks[c]);
297 	/*
298 	 * The regulators are tied to child node device and not to the
299 	 * SATA device itself. So we can't use devm for automatically
300 	 * releasing them. We have to do it manually here.
301 	 */
302 	for (c = 0; c < hpriv->nports; c++)
303 		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
304 			regulator_put(hpriv->target_pwrs[c]);
305 
306 	kfree(hpriv->target_pwrs);
307 }
308 
309 static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
310 				struct device *dev, struct device_node *node)
311 {
312 	int rc;
313 
314 	hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
315 
316 	if (!IS_ERR(hpriv->phys[port]))
317 		return 0;
318 
319 	rc = PTR_ERR(hpriv->phys[port]);
320 	switch (rc) {
321 	case -ENOSYS:
322 		/* No PHY support. Check if PHY is required. */
323 		if (of_find_property(node, "phys", NULL)) {
324 			dev_err(dev,
325 				"couldn't get PHY in node %pOFn: ENOSYS\n",
326 				node);
327 			break;
328 		}
329 		fallthrough;
330 	case -ENODEV:
331 		/* continue normally */
332 		hpriv->phys[port] = NULL;
333 		rc = 0;
334 		break;
335 	case -EPROBE_DEFER:
336 		/* Do not complain yet */
337 		break;
338 
339 	default:
340 		dev_err(dev,
341 			"couldn't get PHY in node %pOFn: %d\n",
342 			node, rc);
343 
344 		break;
345 	}
346 
347 	return rc;
348 }
349 
350 static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
351 				struct device *dev)
352 {
353 	struct regulator *target_pwr;
354 	int rc = 0;
355 
356 	target_pwr = regulator_get(dev, "target");
357 
358 	if (!IS_ERR(target_pwr))
359 		hpriv->target_pwrs[port] = target_pwr;
360 	else
361 		rc = PTR_ERR(target_pwr);
362 
363 	return rc;
364 }
365 
366 /**
367  * ahci_platform_get_resources - Get platform resources
368  * @pdev: platform device to get resources for
369  * @flags: bitmap representing the resource to get
370  *
371  * This function allocates an ahci_host_priv struct, and gets the following
372  * resources, storing a reference to them inside the returned struct:
373  *
374  * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
375  * 2) regulator for controlling the targets power (optional)
376  *    regulator for controlling the AHCI controller (optional)
377  * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
378  *    or for non devicetree enabled platforms a single clock
379  * 4) resets, if flags has AHCI_PLATFORM_GET_RESETS (optional)
380  * 5) phys (optional)
381  *
382  * RETURNS:
383  * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
384  */
385 struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
386 						   unsigned int flags)
387 {
388 	struct device *dev = &pdev->dev;
389 	struct ahci_host_priv *hpriv;
390 	struct clk *clk;
391 	struct device_node *child;
392 	int i, enabled_ports = 0, rc = -ENOMEM, child_nodes;
393 	u32 mask_port_map = 0;
394 
395 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
396 		return ERR_PTR(-ENOMEM);
397 
398 	hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
399 			     GFP_KERNEL);
400 	if (!hpriv)
401 		goto err_out;
402 
403 	devres_add(dev, hpriv);
404 
405 	hpriv->mmio = devm_ioremap_resource(dev,
406 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
407 	if (IS_ERR(hpriv->mmio)) {
408 		rc = PTR_ERR(hpriv->mmio);
409 		goto err_out;
410 	}
411 
412 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
413 		/*
414 		 * For now we must use clk_get(dev, NULL) for the first clock,
415 		 * because some platforms (da850, spear13xx) are not yet
416 		 * converted to use devicetree for clocks.  For new platforms
417 		 * this is equivalent to of_clk_get(dev->of_node, 0).
418 		 */
419 		if (i == 0)
420 			clk = clk_get(dev, NULL);
421 		else
422 			clk = of_clk_get(dev->of_node, i);
423 
424 		if (IS_ERR(clk)) {
425 			rc = PTR_ERR(clk);
426 			if (rc == -EPROBE_DEFER)
427 				goto err_out;
428 			break;
429 		}
430 		hpriv->clks[i] = clk;
431 	}
432 
433 	hpriv->ahci_regulator = devm_regulator_get(dev, "ahci");
434 	if (IS_ERR(hpriv->ahci_regulator)) {
435 		rc = PTR_ERR(hpriv->ahci_regulator);
436 		if (rc != 0)
437 			goto err_out;
438 	}
439 
440 	hpriv->phy_regulator = devm_regulator_get(dev, "phy");
441 	if (IS_ERR(hpriv->phy_regulator)) {
442 		rc = PTR_ERR(hpriv->phy_regulator);
443 		goto err_out;
444 	}
445 
446 	if (flags & AHCI_PLATFORM_GET_RESETS) {
447 		hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
448 		if (IS_ERR(hpriv->rsts)) {
449 			rc = PTR_ERR(hpriv->rsts);
450 			goto err_out;
451 		}
452 	}
453 
454 	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
455 
456 	/*
457 	 * If no sub-node was found, we still need to set nports to
458 	 * one in order to be able to use the
459 	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
460 	 */
461 	if (!child_nodes)
462 		hpriv->nports = 1;
463 
464 	hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);
465 	if (!hpriv->phys) {
466 		rc = -ENOMEM;
467 		goto err_out;
468 	}
469 	/*
470 	 * We cannot use devm_ here, since ahci_platform_put_resources() uses
471 	 * target_pwrs after devm_ have freed memory
472 	 */
473 	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
474 	if (!hpriv->target_pwrs) {
475 		rc = -ENOMEM;
476 		goto err_out;
477 	}
478 
479 	if (child_nodes) {
480 		for_each_child_of_node(dev->of_node, child) {
481 			u32 port;
482 			struct platform_device *port_dev __maybe_unused;
483 
484 			if (!of_device_is_available(child))
485 				continue;
486 
487 			if (of_property_read_u32(child, "reg", &port)) {
488 				rc = -EINVAL;
489 				of_node_put(child);
490 				goto err_out;
491 			}
492 
493 			if (port >= hpriv->nports) {
494 				dev_warn(dev, "invalid port number %d\n", port);
495 				continue;
496 			}
497 			mask_port_map |= BIT(port);
498 
499 #ifdef CONFIG_OF_ADDRESS
500 			of_platform_device_create(child, NULL, NULL);
501 
502 			port_dev = of_find_device_by_node(child);
503 
504 			if (port_dev) {
505 				rc = ahci_platform_get_regulator(hpriv, port,
506 								&port_dev->dev);
507 				if (rc == -EPROBE_DEFER) {
508 					of_node_put(child);
509 					goto err_out;
510 				}
511 			}
512 #endif
513 
514 			rc = ahci_platform_get_phy(hpriv, port, dev, child);
515 			if (rc) {
516 				of_node_put(child);
517 				goto err_out;
518 			}
519 
520 			enabled_ports++;
521 		}
522 		if (!enabled_ports) {
523 			dev_warn(dev, "No port enabled\n");
524 			rc = -ENODEV;
525 			goto err_out;
526 		}
527 
528 		if (!hpriv->mask_port_map)
529 			hpriv->mask_port_map = mask_port_map;
530 	} else {
531 		/*
532 		 * If no sub-node was found, keep this for device tree
533 		 * compatibility
534 		 */
535 		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
536 		if (rc)
537 			goto err_out;
538 
539 		rc = ahci_platform_get_regulator(hpriv, 0, dev);
540 		if (rc == -EPROBE_DEFER)
541 			goto err_out;
542 	}
543 	pm_runtime_enable(dev);
544 	pm_runtime_get_sync(dev);
545 	hpriv->got_runtime_pm = true;
546 
547 	devres_remove_group(dev, NULL);
548 	return hpriv;
549 
550 err_out:
551 	devres_release_group(dev, NULL);
552 	return ERR_PTR(rc);
553 }
554 EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
555 
556 /**
557  * ahci_platform_init_host - Bring up an ahci-platform host
558  * @pdev: platform device pointer for the host
559  * @hpriv: ahci-host private data for the host
560  * @pi_template: template for the ata_port_info to use
561  * @sht: scsi_host_template to use when registering
562  *
563  * This function does all the usual steps needed to bring up an
564  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
565  * must be initialized / enabled before calling this.
566  *
567  * RETURNS:
568  * 0 on success otherwise a negative error code
569  */
570 int ahci_platform_init_host(struct platform_device *pdev,
571 			    struct ahci_host_priv *hpriv,
572 			    const struct ata_port_info *pi_template,
573 			    struct scsi_host_template *sht)
574 {
575 	struct device *dev = &pdev->dev;
576 	struct ata_port_info pi = *pi_template;
577 	const struct ata_port_info *ppi[] = { &pi, NULL };
578 	struct ata_host *host;
579 	int i, irq, n_ports, rc;
580 
581 	irq = platform_get_irq(pdev, 0);
582 	if (irq < 0)
583 		return irq;
584 	if (!irq)
585 		return -EINVAL;
586 
587 	hpriv->irq = irq;
588 
589 	/* prepare host */
590 	pi.private_data = (void *)(unsigned long)hpriv->flags;
591 
592 	ahci_save_initial_config(dev, hpriv);
593 
594 	if (hpriv->cap & HOST_CAP_NCQ)
595 		pi.flags |= ATA_FLAG_NCQ;
596 
597 	if (hpriv->cap & HOST_CAP_PMP)
598 		pi.flags |= ATA_FLAG_PMP;
599 
600 	ahci_set_em_messages(hpriv, &pi);
601 
602 	/* CAP.NP sometimes indicate the index of the last enabled
603 	 * port, at other times, that of the last possible port, so
604 	 * determining the maximum port number requires looking at
605 	 * both CAP.NP and port_map.
606 	 */
607 	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
608 
609 	host = ata_host_alloc_pinfo(dev, ppi, n_ports);
610 	if (!host)
611 		return -ENOMEM;
612 
613 	host->private_data = hpriv;
614 
615 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
616 		host->flags |= ATA_HOST_PARALLEL_SCAN;
617 	else
618 		dev_info(dev, "SSS flag set, parallel bus scan disabled\n");
619 
620 	if (pi.flags & ATA_FLAG_EM)
621 		ahci_reset_em(host);
622 
623 	for (i = 0; i < host->n_ports; i++) {
624 		struct ata_port *ap = host->ports[i];
625 
626 		ata_port_desc(ap, "mmio %pR",
627 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
628 		ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
629 
630 		/* set enclosure management message type */
631 		if (ap->flags & ATA_FLAG_EM)
632 			ap->em_message_type = hpriv->em_msg_type;
633 
634 		/* disabled/not-implemented port */
635 		if (!(hpriv->port_map & (1 << i)))
636 			ap->ops = &ata_dummy_port_ops;
637 	}
638 
639 	if (hpriv->cap & HOST_CAP_64) {
640 		rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
641 		if (rc) {
642 			dev_err(dev, "Failed to enable 64-bit DMA.\n");
643 			return rc;
644 		}
645 	}
646 
647 	rc = ahci_reset_controller(host);
648 	if (rc)
649 		return rc;
650 
651 	ahci_init_controller(host);
652 	ahci_print_info(host, "platform");
653 
654 	return ahci_host_activate(host, sht);
655 }
656 EXPORT_SYMBOL_GPL(ahci_platform_init_host);
657 
658 static void ahci_host_stop(struct ata_host *host)
659 {
660 	struct ahci_host_priv *hpriv = host->private_data;
661 
662 	ahci_platform_disable_resources(hpriv);
663 }
664 
665 /**
666  * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports
667  * @pdev: platform device pointer for the host
668  *
669  * This function is called during system shutdown and performs the minimal
670  * deconfiguration required to ensure that an ahci_platform host cannot
671  * corrupt or otherwise interfere with a new kernel being started with kexec.
672  */
673 void ahci_platform_shutdown(struct platform_device *pdev)
674 {
675 	struct ata_host *host = platform_get_drvdata(pdev);
676 	struct ahci_host_priv *hpriv = host->private_data;
677 	void __iomem *mmio = hpriv->mmio;
678 	int i;
679 
680 	for (i = 0; i < host->n_ports; i++) {
681 		struct ata_port *ap = host->ports[i];
682 
683 		/* Disable port interrupts */
684 		if (ap->ops->freeze)
685 			ap->ops->freeze(ap);
686 
687 		/* Stop the port DMA engines */
688 		if (ap->ops->port_stop)
689 			ap->ops->port_stop(ap);
690 	}
691 
692 	/* Disable and clear host interrupts */
693 	writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL);
694 	readl(mmio + HOST_CTL); /* flush */
695 	writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT);
696 }
697 EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
698 
699 #ifdef CONFIG_PM_SLEEP
700 /**
701  * ahci_platform_suspend_host - Suspend an ahci-platform host
702  * @dev: device pointer for the host
703  *
704  * This function does all the usual steps needed to suspend an
705  * ahci-platform host, note any necessary resources (ie clks, phys, etc.)
706  * must be disabled after calling this.
707  *
708  * RETURNS:
709  * 0 on success otherwise a negative error code
710  */
711 int ahci_platform_suspend_host(struct device *dev)
712 {
713 	struct ata_host *host = dev_get_drvdata(dev);
714 	struct ahci_host_priv *hpriv = host->private_data;
715 	void __iomem *mmio = hpriv->mmio;
716 	u32 ctl;
717 
718 	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
719 		dev_err(dev, "firmware update required for suspend/resume\n");
720 		return -EIO;
721 	}
722 
723 	/*
724 	 * AHCI spec rev1.1 section 8.3.3:
725 	 * Software must disable interrupts prior to requesting a
726 	 * transition of the HBA to D3 state.
727 	 */
728 	ctl = readl(mmio + HOST_CTL);
729 	ctl &= ~HOST_IRQ_EN;
730 	writel(ctl, mmio + HOST_CTL);
731 	readl(mmio + HOST_CTL); /* flush */
732 
733 	if (hpriv->flags & AHCI_HFLAG_SUSPEND_PHYS)
734 		ahci_platform_disable_phys(hpriv);
735 
736 	ata_host_suspend(host, PMSG_SUSPEND);
737 	return 0;
738 }
739 EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
740 
741 /**
742  * ahci_platform_resume_host - Resume an ahci-platform host
743  * @dev: device pointer for the host
744  *
745  * This function does all the usual steps needed to resume an ahci-platform
746  * host, note any necessary resources (ie clks, phys, etc.)  must be
747  * initialized / enabled before calling this.
748  *
749  * RETURNS:
750  * 0 on success otherwise a negative error code
751  */
752 int ahci_platform_resume_host(struct device *dev)
753 {
754 	struct ata_host *host = dev_get_drvdata(dev);
755 	struct ahci_host_priv *hpriv = host->private_data;
756 	int rc;
757 
758 	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
759 		rc = ahci_reset_controller(host);
760 		if (rc)
761 			return rc;
762 
763 		ahci_init_controller(host);
764 	}
765 
766 	if (hpriv->flags & AHCI_HFLAG_SUSPEND_PHYS)
767 		ahci_platform_enable_phys(hpriv);
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