xref: /openbmc/linux/drivers/base/platform.c (revision 68198dca)
1 /*
2  * platform.c - platform 'pseudo' bus for legacy devices
3  *
4  * Copyright (c) 2002-3 Patrick Mochel
5  * Copyright (c) 2002-3 Open Source Development Labs
6  *
7  * This file is released under the GPLv2
8  *
9  * Please see Documentation/driver-model/platform.txt for more
10  * information.
11  */
12 
13 #include <linux/string.h>
14 #include <linux/platform_device.h>
15 #include <linux/of_device.h>
16 #include <linux/of_irq.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/bootmem.h>
21 #include <linux/err.h>
22 #include <linux/slab.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pm_domain.h>
25 #include <linux/idr.h>
26 #include <linux/acpi.h>
27 #include <linux/clk/clk-conf.h>
28 #include <linux/limits.h>
29 #include <linux/property.h>
30 
31 #include "base.h"
32 #include "power/power.h"
33 
34 /* For automatically allocated device IDs */
35 static DEFINE_IDA(platform_devid_ida);
36 
37 struct device platform_bus = {
38 	.init_name	= "platform",
39 };
40 EXPORT_SYMBOL_GPL(platform_bus);
41 
42 /**
43  * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
44  * @pdev: platform device
45  *
46  * This is called before platform_device_add() such that any pdev_archdata may
47  * be setup before the platform_notifier is called.  So if a user needs to
48  * manipulate any relevant information in the pdev_archdata they can do:
49  *
50  *	platform_device_alloc()
51  *	... manipulate ...
52  *	platform_device_add()
53  *
54  * And if they don't care they can just call platform_device_register() and
55  * everything will just work out.
56  */
57 void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
58 {
59 }
60 
61 /**
62  * platform_get_resource - get a resource for a device
63  * @dev: platform device
64  * @type: resource type
65  * @num: resource index
66  */
67 struct resource *platform_get_resource(struct platform_device *dev,
68 				       unsigned int type, unsigned int num)
69 {
70 	int i;
71 
72 	for (i = 0; i < dev->num_resources; i++) {
73 		struct resource *r = &dev->resource[i];
74 
75 		if (type == resource_type(r) && num-- == 0)
76 			return r;
77 	}
78 	return NULL;
79 }
80 EXPORT_SYMBOL_GPL(platform_get_resource);
81 
82 /**
83  * platform_get_irq - get an IRQ for a device
84  * @dev: platform device
85  * @num: IRQ number index
86  */
87 int platform_get_irq(struct platform_device *dev, unsigned int num)
88 {
89 #ifdef CONFIG_SPARC
90 	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
91 	if (!dev || num >= dev->archdata.num_irqs)
92 		return -ENXIO;
93 	return dev->archdata.irqs[num];
94 #else
95 	struct resource *r;
96 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
97 		int ret;
98 
99 		ret = of_irq_get(dev->dev.of_node, num);
100 		if (ret > 0 || ret == -EPROBE_DEFER)
101 			return ret;
102 	}
103 
104 	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
105 	if (has_acpi_companion(&dev->dev)) {
106 		if (r && r->flags & IORESOURCE_DISABLED) {
107 			int ret;
108 
109 			ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
110 			if (ret)
111 				return ret;
112 		}
113 	}
114 
115 	/*
116 	 * The resources may pass trigger flags to the irqs that need
117 	 * to be set up. It so happens that the trigger flags for
118 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
119 	 * settings.
120 	 */
121 	if (r && r->flags & IORESOURCE_BITS) {
122 		struct irq_data *irqd;
123 
124 		irqd = irq_get_irq_data(r->start);
125 		if (!irqd)
126 			return -ENXIO;
127 		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
128 	}
129 
130 	return r ? r->start : -ENXIO;
131 #endif
132 }
133 EXPORT_SYMBOL_GPL(platform_get_irq);
134 
135 /**
136  * platform_irq_count - Count the number of IRQs a platform device uses
137  * @dev: platform device
138  *
139  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
140  */
141 int platform_irq_count(struct platform_device *dev)
142 {
143 	int ret, nr = 0;
144 
145 	while ((ret = platform_get_irq(dev, nr)) >= 0)
146 		nr++;
147 
148 	if (ret == -EPROBE_DEFER)
149 		return ret;
150 
151 	return nr;
152 }
153 EXPORT_SYMBOL_GPL(platform_irq_count);
154 
155 /**
156  * platform_get_resource_byname - get a resource for a device by name
157  * @dev: platform device
158  * @type: resource type
159  * @name: resource name
160  */
161 struct resource *platform_get_resource_byname(struct platform_device *dev,
162 					      unsigned int type,
163 					      const char *name)
164 {
165 	int i;
166 
167 	for (i = 0; i < dev->num_resources; i++) {
168 		struct resource *r = &dev->resource[i];
169 
170 		if (unlikely(!r->name))
171 			continue;
172 
173 		if (type == resource_type(r) && !strcmp(r->name, name))
174 			return r;
175 	}
176 	return NULL;
177 }
178 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
179 
180 /**
181  * platform_get_irq_byname - get an IRQ for a device by name
182  * @dev: platform device
183  * @name: IRQ name
184  */
185 int platform_get_irq_byname(struct platform_device *dev, const char *name)
186 {
187 	struct resource *r;
188 
189 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
190 		int ret;
191 
192 		ret = of_irq_get_byname(dev->dev.of_node, name);
193 		if (ret > 0 || ret == -EPROBE_DEFER)
194 			return ret;
195 	}
196 
197 	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
198 	return r ? r->start : -ENXIO;
199 }
200 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
201 
202 /**
203  * platform_add_devices - add a numbers of platform devices
204  * @devs: array of platform devices to add
205  * @num: number of platform devices in array
206  */
207 int platform_add_devices(struct platform_device **devs, int num)
208 {
209 	int i, ret = 0;
210 
211 	for (i = 0; i < num; i++) {
212 		ret = platform_device_register(devs[i]);
213 		if (ret) {
214 			while (--i >= 0)
215 				platform_device_unregister(devs[i]);
216 			break;
217 		}
218 	}
219 
220 	return ret;
221 }
222 EXPORT_SYMBOL_GPL(platform_add_devices);
223 
224 struct platform_object {
225 	struct platform_device pdev;
226 	char name[];
227 };
228 
229 /**
230  * platform_device_put - destroy a platform device
231  * @pdev: platform device to free
232  *
233  * Free all memory associated with a platform device.  This function must
234  * _only_ be externally called in error cases.  All other usage is a bug.
235  */
236 void platform_device_put(struct platform_device *pdev)
237 {
238 	if (pdev)
239 		put_device(&pdev->dev);
240 }
241 EXPORT_SYMBOL_GPL(platform_device_put);
242 
243 static void platform_device_release(struct device *dev)
244 {
245 	struct platform_object *pa = container_of(dev, struct platform_object,
246 						  pdev.dev);
247 
248 	of_device_node_put(&pa->pdev.dev);
249 	kfree(pa->pdev.dev.platform_data);
250 	kfree(pa->pdev.mfd_cell);
251 	kfree(pa->pdev.resource);
252 	kfree(pa->pdev.driver_override);
253 	kfree(pa);
254 }
255 
256 /**
257  * platform_device_alloc - create a platform device
258  * @name: base name of the device we're adding
259  * @id: instance id
260  *
261  * Create a platform device object which can have other objects attached
262  * to it, and which will have attached objects freed when it is released.
263  */
264 struct platform_device *platform_device_alloc(const char *name, int id)
265 {
266 	struct platform_object *pa;
267 
268 	pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
269 	if (pa) {
270 		strcpy(pa->name, name);
271 		pa->pdev.name = pa->name;
272 		pa->pdev.id = id;
273 		device_initialize(&pa->pdev.dev);
274 		pa->pdev.dev.release = platform_device_release;
275 		arch_setup_pdev_archdata(&pa->pdev);
276 	}
277 
278 	return pa ? &pa->pdev : NULL;
279 }
280 EXPORT_SYMBOL_GPL(platform_device_alloc);
281 
282 /**
283  * platform_device_add_resources - add resources to a platform device
284  * @pdev: platform device allocated by platform_device_alloc to add resources to
285  * @res: set of resources that needs to be allocated for the device
286  * @num: number of resources
287  *
288  * Add a copy of the resources to the platform device.  The memory
289  * associated with the resources will be freed when the platform device is
290  * released.
291  */
292 int platform_device_add_resources(struct platform_device *pdev,
293 				  const struct resource *res, unsigned int num)
294 {
295 	struct resource *r = NULL;
296 
297 	if (res) {
298 		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
299 		if (!r)
300 			return -ENOMEM;
301 	}
302 
303 	kfree(pdev->resource);
304 	pdev->resource = r;
305 	pdev->num_resources = num;
306 	return 0;
307 }
308 EXPORT_SYMBOL_GPL(platform_device_add_resources);
309 
310 /**
311  * platform_device_add_data - add platform-specific data to a platform device
312  * @pdev: platform device allocated by platform_device_alloc to add resources to
313  * @data: platform specific data for this platform device
314  * @size: size of platform specific data
315  *
316  * Add a copy of platform specific data to the platform device's
317  * platform_data pointer.  The memory associated with the platform data
318  * will be freed when the platform device is released.
319  */
320 int platform_device_add_data(struct platform_device *pdev, const void *data,
321 			     size_t size)
322 {
323 	void *d = NULL;
324 
325 	if (data) {
326 		d = kmemdup(data, size, GFP_KERNEL);
327 		if (!d)
328 			return -ENOMEM;
329 	}
330 
331 	kfree(pdev->dev.platform_data);
332 	pdev->dev.platform_data = d;
333 	return 0;
334 }
335 EXPORT_SYMBOL_GPL(platform_device_add_data);
336 
337 /**
338  * platform_device_add_properties - add built-in properties to a platform device
339  * @pdev: platform device to add properties to
340  * @properties: null terminated array of properties to add
341  *
342  * The function will take deep copy of @properties and attach the copy to the
343  * platform device. The memory associated with properties will be freed when the
344  * platform device is released.
345  */
346 int platform_device_add_properties(struct platform_device *pdev,
347 				   const struct property_entry *properties)
348 {
349 	return device_add_properties(&pdev->dev, properties);
350 }
351 EXPORT_SYMBOL_GPL(platform_device_add_properties);
352 
353 /**
354  * platform_device_add - add a platform device to device hierarchy
355  * @pdev: platform device we're adding
356  *
357  * This is part 2 of platform_device_register(), though may be called
358  * separately _iff_ pdev was allocated by platform_device_alloc().
359  */
360 int platform_device_add(struct platform_device *pdev)
361 {
362 	int i, ret;
363 
364 	if (!pdev)
365 		return -EINVAL;
366 
367 	if (!pdev->dev.parent)
368 		pdev->dev.parent = &platform_bus;
369 
370 	pdev->dev.bus = &platform_bus_type;
371 
372 	switch (pdev->id) {
373 	default:
374 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
375 		break;
376 	case PLATFORM_DEVID_NONE:
377 		dev_set_name(&pdev->dev, "%s", pdev->name);
378 		break;
379 	case PLATFORM_DEVID_AUTO:
380 		/*
381 		 * Automatically allocated device ID. We mark it as such so
382 		 * that we remember it must be freed, and we append a suffix
383 		 * to avoid namespace collision with explicit IDs.
384 		 */
385 		ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
386 		if (ret < 0)
387 			goto err_out;
388 		pdev->id = ret;
389 		pdev->id_auto = true;
390 		dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
391 		break;
392 	}
393 
394 	for (i = 0; i < pdev->num_resources; i++) {
395 		struct resource *p, *r = &pdev->resource[i];
396 
397 		if (r->name == NULL)
398 			r->name = dev_name(&pdev->dev);
399 
400 		p = r->parent;
401 		if (!p) {
402 			if (resource_type(r) == IORESOURCE_MEM)
403 				p = &iomem_resource;
404 			else if (resource_type(r) == IORESOURCE_IO)
405 				p = &ioport_resource;
406 		}
407 
408 		if (p && insert_resource(p, r)) {
409 			dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
410 			ret = -EBUSY;
411 			goto failed;
412 		}
413 	}
414 
415 	pr_debug("Registering platform device '%s'. Parent at %s\n",
416 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
417 
418 	ret = device_add(&pdev->dev);
419 	if (ret == 0)
420 		return ret;
421 
422  failed:
423 	if (pdev->id_auto) {
424 		ida_simple_remove(&platform_devid_ida, pdev->id);
425 		pdev->id = PLATFORM_DEVID_AUTO;
426 	}
427 
428 	while (--i >= 0) {
429 		struct resource *r = &pdev->resource[i];
430 		if (r->parent)
431 			release_resource(r);
432 	}
433 
434  err_out:
435 	return ret;
436 }
437 EXPORT_SYMBOL_GPL(platform_device_add);
438 
439 /**
440  * platform_device_del - remove a platform-level device
441  * @pdev: platform device we're removing
442  *
443  * Note that this function will also release all memory- and port-based
444  * resources owned by the device (@dev->resource).  This function must
445  * _only_ be externally called in error cases.  All other usage is a bug.
446  */
447 void platform_device_del(struct platform_device *pdev)
448 {
449 	int i;
450 
451 	if (pdev) {
452 		device_remove_properties(&pdev->dev);
453 		device_del(&pdev->dev);
454 
455 		if (pdev->id_auto) {
456 			ida_simple_remove(&platform_devid_ida, pdev->id);
457 			pdev->id = PLATFORM_DEVID_AUTO;
458 		}
459 
460 		for (i = 0; i < pdev->num_resources; i++) {
461 			struct resource *r = &pdev->resource[i];
462 			if (r->parent)
463 				release_resource(r);
464 		}
465 	}
466 }
467 EXPORT_SYMBOL_GPL(platform_device_del);
468 
469 /**
470  * platform_device_register - add a platform-level device
471  * @pdev: platform device we're adding
472  */
473 int platform_device_register(struct platform_device *pdev)
474 {
475 	device_initialize(&pdev->dev);
476 	arch_setup_pdev_archdata(pdev);
477 	return platform_device_add(pdev);
478 }
479 EXPORT_SYMBOL_GPL(platform_device_register);
480 
481 /**
482  * platform_device_unregister - unregister a platform-level device
483  * @pdev: platform device we're unregistering
484  *
485  * Unregistration is done in 2 steps. First we release all resources
486  * and remove it from the subsystem, then we drop reference count by
487  * calling platform_device_put().
488  */
489 void platform_device_unregister(struct platform_device *pdev)
490 {
491 	platform_device_del(pdev);
492 	platform_device_put(pdev);
493 }
494 EXPORT_SYMBOL_GPL(platform_device_unregister);
495 
496 /**
497  * platform_device_register_full - add a platform-level device with
498  * resources and platform-specific data
499  *
500  * @pdevinfo: data used to create device
501  *
502  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
503  */
504 struct platform_device *platform_device_register_full(
505 		const struct platform_device_info *pdevinfo)
506 {
507 	int ret = -ENOMEM;
508 	struct platform_device *pdev;
509 
510 	pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
511 	if (!pdev)
512 		goto err_alloc;
513 
514 	pdev->dev.parent = pdevinfo->parent;
515 	pdev->dev.fwnode = pdevinfo->fwnode;
516 
517 	if (pdevinfo->dma_mask) {
518 		/*
519 		 * This memory isn't freed when the device is put,
520 		 * I don't have a nice idea for that though.  Conceptually
521 		 * dma_mask in struct device should not be a pointer.
522 		 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
523 		 */
524 		pdev->dev.dma_mask =
525 			kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
526 		if (!pdev->dev.dma_mask)
527 			goto err;
528 
529 		*pdev->dev.dma_mask = pdevinfo->dma_mask;
530 		pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
531 	}
532 
533 	ret = platform_device_add_resources(pdev,
534 			pdevinfo->res, pdevinfo->num_res);
535 	if (ret)
536 		goto err;
537 
538 	ret = platform_device_add_data(pdev,
539 			pdevinfo->data, pdevinfo->size_data);
540 	if (ret)
541 		goto err;
542 
543 	if (pdevinfo->properties) {
544 		ret = platform_device_add_properties(pdev,
545 						     pdevinfo->properties);
546 		if (ret)
547 			goto err;
548 	}
549 
550 	ret = platform_device_add(pdev);
551 	if (ret) {
552 err:
553 		ACPI_COMPANION_SET(&pdev->dev, NULL);
554 		kfree(pdev->dev.dma_mask);
555 
556 err_alloc:
557 		platform_device_put(pdev);
558 		return ERR_PTR(ret);
559 	}
560 
561 	return pdev;
562 }
563 EXPORT_SYMBOL_GPL(platform_device_register_full);
564 
565 static int platform_drv_probe(struct device *_dev)
566 {
567 	struct platform_driver *drv = to_platform_driver(_dev->driver);
568 	struct platform_device *dev = to_platform_device(_dev);
569 	int ret;
570 
571 	ret = of_clk_set_defaults(_dev->of_node, false);
572 	if (ret < 0)
573 		return ret;
574 
575 	ret = dev_pm_domain_attach(_dev, true);
576 	if (ret != -EPROBE_DEFER) {
577 		if (drv->probe) {
578 			ret = drv->probe(dev);
579 			if (ret)
580 				dev_pm_domain_detach(_dev, true);
581 		} else {
582 			/* don't fail if just dev_pm_domain_attach failed */
583 			ret = 0;
584 		}
585 	}
586 
587 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
588 		dev_warn(_dev, "probe deferral not supported\n");
589 		ret = -ENXIO;
590 	}
591 
592 	return ret;
593 }
594 
595 static int platform_drv_probe_fail(struct device *_dev)
596 {
597 	return -ENXIO;
598 }
599 
600 static int platform_drv_remove(struct device *_dev)
601 {
602 	struct platform_driver *drv = to_platform_driver(_dev->driver);
603 	struct platform_device *dev = to_platform_device(_dev);
604 	int ret = 0;
605 
606 	if (drv->remove)
607 		ret = drv->remove(dev);
608 	dev_pm_domain_detach(_dev, true);
609 
610 	return ret;
611 }
612 
613 static void platform_drv_shutdown(struct device *_dev)
614 {
615 	struct platform_driver *drv = to_platform_driver(_dev->driver);
616 	struct platform_device *dev = to_platform_device(_dev);
617 
618 	if (drv->shutdown)
619 		drv->shutdown(dev);
620 }
621 
622 /**
623  * __platform_driver_register - register a driver for platform-level devices
624  * @drv: platform driver structure
625  * @owner: owning module/driver
626  */
627 int __platform_driver_register(struct platform_driver *drv,
628 				struct module *owner)
629 {
630 	drv->driver.owner = owner;
631 	drv->driver.bus = &platform_bus_type;
632 	drv->driver.probe = platform_drv_probe;
633 	drv->driver.remove = platform_drv_remove;
634 	drv->driver.shutdown = platform_drv_shutdown;
635 
636 	return driver_register(&drv->driver);
637 }
638 EXPORT_SYMBOL_GPL(__platform_driver_register);
639 
640 /**
641  * platform_driver_unregister - unregister a driver for platform-level devices
642  * @drv: platform driver structure
643  */
644 void platform_driver_unregister(struct platform_driver *drv)
645 {
646 	driver_unregister(&drv->driver);
647 }
648 EXPORT_SYMBOL_GPL(platform_driver_unregister);
649 
650 /**
651  * __platform_driver_probe - register driver for non-hotpluggable device
652  * @drv: platform driver structure
653  * @probe: the driver probe routine, probably from an __init section
654  * @module: module which will be the owner of the driver
655  *
656  * Use this instead of platform_driver_register() when you know the device
657  * is not hotpluggable and has already been registered, and you want to
658  * remove its run-once probe() infrastructure from memory after the driver
659  * has bound to the device.
660  *
661  * One typical use for this would be with drivers for controllers integrated
662  * into system-on-chip processors, where the controller devices have been
663  * configured as part of board setup.
664  *
665  * Note that this is incompatible with deferred probing.
666  *
667  * Returns zero if the driver registered and bound to a device, else returns
668  * a negative error code and with the driver not registered.
669  */
670 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
671 		int (*probe)(struct platform_device *), struct module *module)
672 {
673 	int retval, code;
674 
675 	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
676 		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
677 			 drv->driver.name, __func__);
678 		return -EINVAL;
679 	}
680 
681 	/*
682 	 * We have to run our probes synchronously because we check if
683 	 * we find any devices to bind to and exit with error if there
684 	 * are any.
685 	 */
686 	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
687 
688 	/*
689 	 * Prevent driver from requesting probe deferral to avoid further
690 	 * futile probe attempts.
691 	 */
692 	drv->prevent_deferred_probe = true;
693 
694 	/* make sure driver won't have bind/unbind attributes */
695 	drv->driver.suppress_bind_attrs = true;
696 
697 	/* temporary section violation during probe() */
698 	drv->probe = probe;
699 	retval = code = __platform_driver_register(drv, module);
700 
701 	/*
702 	 * Fixup that section violation, being paranoid about code scanning
703 	 * the list of drivers in order to probe new devices.  Check to see
704 	 * if the probe was successful, and make sure any forced probes of
705 	 * new devices fail.
706 	 */
707 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
708 	drv->probe = NULL;
709 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
710 		retval = -ENODEV;
711 	drv->driver.probe = platform_drv_probe_fail;
712 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
713 
714 	if (code != retval)
715 		platform_driver_unregister(drv);
716 	return retval;
717 }
718 EXPORT_SYMBOL_GPL(__platform_driver_probe);
719 
720 /**
721  * __platform_create_bundle - register driver and create corresponding device
722  * @driver: platform driver structure
723  * @probe: the driver probe routine, probably from an __init section
724  * @res: set of resources that needs to be allocated for the device
725  * @n_res: number of resources
726  * @data: platform specific data for this platform device
727  * @size: size of platform specific data
728  * @module: module which will be the owner of the driver
729  *
730  * Use this in legacy-style modules that probe hardware directly and
731  * register a single platform device and corresponding platform driver.
732  *
733  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
734  */
735 struct platform_device * __init_or_module __platform_create_bundle(
736 			struct platform_driver *driver,
737 			int (*probe)(struct platform_device *),
738 			struct resource *res, unsigned int n_res,
739 			const void *data, size_t size, struct module *module)
740 {
741 	struct platform_device *pdev;
742 	int error;
743 
744 	pdev = platform_device_alloc(driver->driver.name, -1);
745 	if (!pdev) {
746 		error = -ENOMEM;
747 		goto err_out;
748 	}
749 
750 	error = platform_device_add_resources(pdev, res, n_res);
751 	if (error)
752 		goto err_pdev_put;
753 
754 	error = platform_device_add_data(pdev, data, size);
755 	if (error)
756 		goto err_pdev_put;
757 
758 	error = platform_device_add(pdev);
759 	if (error)
760 		goto err_pdev_put;
761 
762 	error = __platform_driver_probe(driver, probe, module);
763 	if (error)
764 		goto err_pdev_del;
765 
766 	return pdev;
767 
768 err_pdev_del:
769 	platform_device_del(pdev);
770 err_pdev_put:
771 	platform_device_put(pdev);
772 err_out:
773 	return ERR_PTR(error);
774 }
775 EXPORT_SYMBOL_GPL(__platform_create_bundle);
776 
777 /**
778  * __platform_register_drivers - register an array of platform drivers
779  * @drivers: an array of drivers to register
780  * @count: the number of drivers to register
781  * @owner: module owning the drivers
782  *
783  * Registers platform drivers specified by an array. On failure to register a
784  * driver, all previously registered drivers will be unregistered. Callers of
785  * this API should use platform_unregister_drivers() to unregister drivers in
786  * the reverse order.
787  *
788  * Returns: 0 on success or a negative error code on failure.
789  */
790 int __platform_register_drivers(struct platform_driver * const *drivers,
791 				unsigned int count, struct module *owner)
792 {
793 	unsigned int i;
794 	int err;
795 
796 	for (i = 0; i < count; i++) {
797 		pr_debug("registering platform driver %ps\n", drivers[i]);
798 
799 		err = __platform_driver_register(drivers[i], owner);
800 		if (err < 0) {
801 			pr_err("failed to register platform driver %ps: %d\n",
802 			       drivers[i], err);
803 			goto error;
804 		}
805 	}
806 
807 	return 0;
808 
809 error:
810 	while (i--) {
811 		pr_debug("unregistering platform driver %ps\n", drivers[i]);
812 		platform_driver_unregister(drivers[i]);
813 	}
814 
815 	return err;
816 }
817 EXPORT_SYMBOL_GPL(__platform_register_drivers);
818 
819 /**
820  * platform_unregister_drivers - unregister an array of platform drivers
821  * @drivers: an array of drivers to unregister
822  * @count: the number of drivers to unregister
823  *
824  * Unegisters platform drivers specified by an array. This is typically used
825  * to complement an earlier call to platform_register_drivers(). Drivers are
826  * unregistered in the reverse order in which they were registered.
827  */
828 void platform_unregister_drivers(struct platform_driver * const *drivers,
829 				 unsigned int count)
830 {
831 	while (count--) {
832 		pr_debug("unregistering platform driver %ps\n", drivers[count]);
833 		platform_driver_unregister(drivers[count]);
834 	}
835 }
836 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
837 
838 /* modalias support enables more hands-off userspace setup:
839  * (a) environment variable lets new-style hotplug events work once system is
840  *     fully running:  "modprobe $MODALIAS"
841  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
842  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
843  */
844 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
845 			     char *buf)
846 {
847 	struct platform_device	*pdev = to_platform_device(dev);
848 	int len;
849 
850 	len = of_device_modalias(dev, buf, PAGE_SIZE);
851 	if (len != -ENODEV)
852 		return len;
853 
854 	len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
855 	if (len != -ENODEV)
856 		return len;
857 
858 	len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
859 
860 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
861 }
862 static DEVICE_ATTR_RO(modalias);
863 
864 static ssize_t driver_override_store(struct device *dev,
865 				     struct device_attribute *attr,
866 				     const char *buf, size_t count)
867 {
868 	struct platform_device *pdev = to_platform_device(dev);
869 	char *driver_override, *old, *cp;
870 
871 	/* We need to keep extra room for a newline */
872 	if (count >= (PAGE_SIZE - 1))
873 		return -EINVAL;
874 
875 	driver_override = kstrndup(buf, count, GFP_KERNEL);
876 	if (!driver_override)
877 		return -ENOMEM;
878 
879 	cp = strchr(driver_override, '\n');
880 	if (cp)
881 		*cp = '\0';
882 
883 	device_lock(dev);
884 	old = pdev->driver_override;
885 	if (strlen(driver_override)) {
886 		pdev->driver_override = driver_override;
887 	} else {
888 		kfree(driver_override);
889 		pdev->driver_override = NULL;
890 	}
891 	device_unlock(dev);
892 
893 	kfree(old);
894 
895 	return count;
896 }
897 
898 static ssize_t driver_override_show(struct device *dev,
899 				    struct device_attribute *attr, char *buf)
900 {
901 	struct platform_device *pdev = to_platform_device(dev);
902 	ssize_t len;
903 
904 	device_lock(dev);
905 	len = sprintf(buf, "%s\n", pdev->driver_override);
906 	device_unlock(dev);
907 	return len;
908 }
909 static DEVICE_ATTR_RW(driver_override);
910 
911 
912 static struct attribute *platform_dev_attrs[] = {
913 	&dev_attr_modalias.attr,
914 	&dev_attr_driver_override.attr,
915 	NULL,
916 };
917 ATTRIBUTE_GROUPS(platform_dev);
918 
919 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
920 {
921 	struct platform_device	*pdev = to_platform_device(dev);
922 	int rc;
923 
924 	/* Some devices have extra OF data and an OF-style MODALIAS */
925 	rc = of_device_uevent_modalias(dev, env);
926 	if (rc != -ENODEV)
927 		return rc;
928 
929 	rc = acpi_device_uevent_modalias(dev, env);
930 	if (rc != -ENODEV)
931 		return rc;
932 
933 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
934 			pdev->name);
935 	return 0;
936 }
937 
938 static const struct platform_device_id *platform_match_id(
939 			const struct platform_device_id *id,
940 			struct platform_device *pdev)
941 {
942 	while (id->name[0]) {
943 		if (strcmp(pdev->name, id->name) == 0) {
944 			pdev->id_entry = id;
945 			return id;
946 		}
947 		id++;
948 	}
949 	return NULL;
950 }
951 
952 /**
953  * platform_match - bind platform device to platform driver.
954  * @dev: device.
955  * @drv: driver.
956  *
957  * Platform device IDs are assumed to be encoded like this:
958  * "<name><instance>", where <name> is a short description of the type of
959  * device, like "pci" or "floppy", and <instance> is the enumerated
960  * instance of the device, like '0' or '42'.  Driver IDs are simply
961  * "<name>".  So, extract the <name> from the platform_device structure,
962  * and compare it against the name of the driver. Return whether they match
963  * or not.
964  */
965 static int platform_match(struct device *dev, struct device_driver *drv)
966 {
967 	struct platform_device *pdev = to_platform_device(dev);
968 	struct platform_driver *pdrv = to_platform_driver(drv);
969 
970 	/* When driver_override is set, only bind to the matching driver */
971 	if (pdev->driver_override)
972 		return !strcmp(pdev->driver_override, drv->name);
973 
974 	/* Attempt an OF style match first */
975 	if (of_driver_match_device(dev, drv))
976 		return 1;
977 
978 	/* Then try ACPI style match */
979 	if (acpi_driver_match_device(dev, drv))
980 		return 1;
981 
982 	/* Then try to match against the id table */
983 	if (pdrv->id_table)
984 		return platform_match_id(pdrv->id_table, pdev) != NULL;
985 
986 	/* fall-back to driver name match */
987 	return (strcmp(pdev->name, drv->name) == 0);
988 }
989 
990 #ifdef CONFIG_PM_SLEEP
991 
992 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
993 {
994 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
995 	struct platform_device *pdev = to_platform_device(dev);
996 	int ret = 0;
997 
998 	if (dev->driver && pdrv->suspend)
999 		ret = pdrv->suspend(pdev, mesg);
1000 
1001 	return ret;
1002 }
1003 
1004 static int platform_legacy_resume(struct device *dev)
1005 {
1006 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1007 	struct platform_device *pdev = to_platform_device(dev);
1008 	int ret = 0;
1009 
1010 	if (dev->driver && pdrv->resume)
1011 		ret = pdrv->resume(pdev);
1012 
1013 	return ret;
1014 }
1015 
1016 #endif /* CONFIG_PM_SLEEP */
1017 
1018 #ifdef CONFIG_SUSPEND
1019 
1020 int platform_pm_suspend(struct device *dev)
1021 {
1022 	struct device_driver *drv = dev->driver;
1023 	int ret = 0;
1024 
1025 	if (!drv)
1026 		return 0;
1027 
1028 	if (drv->pm) {
1029 		if (drv->pm->suspend)
1030 			ret = drv->pm->suspend(dev);
1031 	} else {
1032 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1033 	}
1034 
1035 	return ret;
1036 }
1037 
1038 int platform_pm_resume(struct device *dev)
1039 {
1040 	struct device_driver *drv = dev->driver;
1041 	int ret = 0;
1042 
1043 	if (!drv)
1044 		return 0;
1045 
1046 	if (drv->pm) {
1047 		if (drv->pm->resume)
1048 			ret = drv->pm->resume(dev);
1049 	} else {
1050 		ret = platform_legacy_resume(dev);
1051 	}
1052 
1053 	return ret;
1054 }
1055 
1056 #endif /* CONFIG_SUSPEND */
1057 
1058 #ifdef CONFIG_HIBERNATE_CALLBACKS
1059 
1060 int platform_pm_freeze(struct device *dev)
1061 {
1062 	struct device_driver *drv = dev->driver;
1063 	int ret = 0;
1064 
1065 	if (!drv)
1066 		return 0;
1067 
1068 	if (drv->pm) {
1069 		if (drv->pm->freeze)
1070 			ret = drv->pm->freeze(dev);
1071 	} else {
1072 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1073 	}
1074 
1075 	return ret;
1076 }
1077 
1078 int platform_pm_thaw(struct device *dev)
1079 {
1080 	struct device_driver *drv = dev->driver;
1081 	int ret = 0;
1082 
1083 	if (!drv)
1084 		return 0;
1085 
1086 	if (drv->pm) {
1087 		if (drv->pm->thaw)
1088 			ret = drv->pm->thaw(dev);
1089 	} else {
1090 		ret = platform_legacy_resume(dev);
1091 	}
1092 
1093 	return ret;
1094 }
1095 
1096 int platform_pm_poweroff(struct device *dev)
1097 {
1098 	struct device_driver *drv = dev->driver;
1099 	int ret = 0;
1100 
1101 	if (!drv)
1102 		return 0;
1103 
1104 	if (drv->pm) {
1105 		if (drv->pm->poweroff)
1106 			ret = drv->pm->poweroff(dev);
1107 	} else {
1108 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1109 	}
1110 
1111 	return ret;
1112 }
1113 
1114 int platform_pm_restore(struct device *dev)
1115 {
1116 	struct device_driver *drv = dev->driver;
1117 	int ret = 0;
1118 
1119 	if (!drv)
1120 		return 0;
1121 
1122 	if (drv->pm) {
1123 		if (drv->pm->restore)
1124 			ret = drv->pm->restore(dev);
1125 	} else {
1126 		ret = platform_legacy_resume(dev);
1127 	}
1128 
1129 	return ret;
1130 }
1131 
1132 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1133 
1134 static const struct dev_pm_ops platform_dev_pm_ops = {
1135 	.runtime_suspend = pm_generic_runtime_suspend,
1136 	.runtime_resume = pm_generic_runtime_resume,
1137 	USE_PLATFORM_PM_SLEEP_OPS
1138 };
1139 
1140 struct bus_type platform_bus_type = {
1141 	.name		= "platform",
1142 	.dev_groups	= platform_dev_groups,
1143 	.match		= platform_match,
1144 	.uevent		= platform_uevent,
1145 	.pm		= &platform_dev_pm_ops,
1146 	.force_dma	= true,
1147 };
1148 EXPORT_SYMBOL_GPL(platform_bus_type);
1149 
1150 int __init platform_bus_init(void)
1151 {
1152 	int error;
1153 
1154 	early_platform_cleanup();
1155 
1156 	error = device_register(&platform_bus);
1157 	if (error)
1158 		return error;
1159 	error =  bus_register(&platform_bus_type);
1160 	if (error)
1161 		device_unregister(&platform_bus);
1162 	of_platform_register_reconfig_notifier();
1163 	return error;
1164 }
1165 
1166 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
1167 u64 dma_get_required_mask(struct device *dev)
1168 {
1169 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
1170 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
1171 	u64 mask;
1172 
1173 	if (!high_totalram) {
1174 		/* convert to mask just covering totalram */
1175 		low_totalram = (1 << (fls(low_totalram) - 1));
1176 		low_totalram += low_totalram - 1;
1177 		mask = low_totalram;
1178 	} else {
1179 		high_totalram = (1 << (fls(high_totalram) - 1));
1180 		high_totalram += high_totalram - 1;
1181 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
1182 	}
1183 	return mask;
1184 }
1185 EXPORT_SYMBOL_GPL(dma_get_required_mask);
1186 #endif
1187 
1188 static __initdata LIST_HEAD(early_platform_driver_list);
1189 static __initdata LIST_HEAD(early_platform_device_list);
1190 
1191 /**
1192  * early_platform_driver_register - register early platform driver
1193  * @epdrv: early_platform driver structure
1194  * @buf: string passed from early_param()
1195  *
1196  * Helper function for early_platform_init() / early_platform_init_buffer()
1197  */
1198 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1199 					  char *buf)
1200 {
1201 	char *tmp;
1202 	int n;
1203 
1204 	/* Simply add the driver to the end of the global list.
1205 	 * Drivers will by default be put on the list in compiled-in order.
1206 	 */
1207 	if (!epdrv->list.next) {
1208 		INIT_LIST_HEAD(&epdrv->list);
1209 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1210 	}
1211 
1212 	/* If the user has specified device then make sure the driver
1213 	 * gets prioritized. The driver of the last device specified on
1214 	 * command line will be put first on the list.
1215 	 */
1216 	n = strlen(epdrv->pdrv->driver.name);
1217 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1218 		list_move(&epdrv->list, &early_platform_driver_list);
1219 
1220 		/* Allow passing parameters after device name */
1221 		if (buf[n] == '\0' || buf[n] == ',')
1222 			epdrv->requested_id = -1;
1223 		else {
1224 			epdrv->requested_id = simple_strtoul(&buf[n + 1],
1225 							     &tmp, 10);
1226 
1227 			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1228 				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1229 				n = 0;
1230 			} else
1231 				n += strcspn(&buf[n + 1], ",") + 1;
1232 		}
1233 
1234 		if (buf[n] == ',')
1235 			n++;
1236 
1237 		if (epdrv->bufsize) {
1238 			memcpy(epdrv->buffer, &buf[n],
1239 			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1240 			epdrv->buffer[epdrv->bufsize - 1] = '\0';
1241 		}
1242 	}
1243 
1244 	return 0;
1245 }
1246 
1247 /**
1248  * early_platform_add_devices - adds a number of early platform devices
1249  * @devs: array of early platform devices to add
1250  * @num: number of early platform devices in array
1251  *
1252  * Used by early architecture code to register early platform devices and
1253  * their platform data.
1254  */
1255 void __init early_platform_add_devices(struct platform_device **devs, int num)
1256 {
1257 	struct device *dev;
1258 	int i;
1259 
1260 	/* simply add the devices to list */
1261 	for (i = 0; i < num; i++) {
1262 		dev = &devs[i]->dev;
1263 
1264 		if (!dev->devres_head.next) {
1265 			pm_runtime_early_init(dev);
1266 			INIT_LIST_HEAD(&dev->devres_head);
1267 			list_add_tail(&dev->devres_head,
1268 				      &early_platform_device_list);
1269 		}
1270 	}
1271 }
1272 
1273 /**
1274  * early_platform_driver_register_all - register early platform drivers
1275  * @class_str: string to identify early platform driver class
1276  *
1277  * Used by architecture code to register all early platform drivers
1278  * for a certain class. If omitted then only early platform drivers
1279  * with matching kernel command line class parameters will be registered.
1280  */
1281 void __init early_platform_driver_register_all(char *class_str)
1282 {
1283 	/* The "class_str" parameter may or may not be present on the kernel
1284 	 * command line. If it is present then there may be more than one
1285 	 * matching parameter.
1286 	 *
1287 	 * Since we register our early platform drivers using early_param()
1288 	 * we need to make sure that they also get registered in the case
1289 	 * when the parameter is missing from the kernel command line.
1290 	 *
1291 	 * We use parse_early_options() to make sure the early_param() gets
1292 	 * called at least once. The early_param() may be called more than
1293 	 * once since the name of the preferred device may be specified on
1294 	 * the kernel command line. early_platform_driver_register() handles
1295 	 * this case for us.
1296 	 */
1297 	parse_early_options(class_str);
1298 }
1299 
1300 /**
1301  * early_platform_match - find early platform device matching driver
1302  * @epdrv: early platform driver structure
1303  * @id: id to match against
1304  */
1305 static struct platform_device * __init
1306 early_platform_match(struct early_platform_driver *epdrv, int id)
1307 {
1308 	struct platform_device *pd;
1309 
1310 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1311 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1312 			if (pd->id == id)
1313 				return pd;
1314 
1315 	return NULL;
1316 }
1317 
1318 /**
1319  * early_platform_left - check if early platform driver has matching devices
1320  * @epdrv: early platform driver structure
1321  * @id: return true if id or above exists
1322  */
1323 static int __init early_platform_left(struct early_platform_driver *epdrv,
1324 				       int id)
1325 {
1326 	struct platform_device *pd;
1327 
1328 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1329 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1330 			if (pd->id >= id)
1331 				return 1;
1332 
1333 	return 0;
1334 }
1335 
1336 /**
1337  * early_platform_driver_probe_id - probe drivers matching class_str and id
1338  * @class_str: string to identify early platform driver class
1339  * @id: id to match against
1340  * @nr_probe: number of platform devices to successfully probe before exiting
1341  */
1342 static int __init early_platform_driver_probe_id(char *class_str,
1343 						 int id,
1344 						 int nr_probe)
1345 {
1346 	struct early_platform_driver *epdrv;
1347 	struct platform_device *match;
1348 	int match_id;
1349 	int n = 0;
1350 	int left = 0;
1351 
1352 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1353 		/* only use drivers matching our class_str */
1354 		if (strcmp(class_str, epdrv->class_str))
1355 			continue;
1356 
1357 		if (id == -2) {
1358 			match_id = epdrv->requested_id;
1359 			left = 1;
1360 
1361 		} else {
1362 			match_id = id;
1363 			left += early_platform_left(epdrv, id);
1364 
1365 			/* skip requested id */
1366 			switch (epdrv->requested_id) {
1367 			case EARLY_PLATFORM_ID_ERROR:
1368 			case EARLY_PLATFORM_ID_UNSET:
1369 				break;
1370 			default:
1371 				if (epdrv->requested_id == id)
1372 					match_id = EARLY_PLATFORM_ID_UNSET;
1373 			}
1374 		}
1375 
1376 		switch (match_id) {
1377 		case EARLY_PLATFORM_ID_ERROR:
1378 			pr_warn("%s: unable to parse %s parameter\n",
1379 				class_str, epdrv->pdrv->driver.name);
1380 			/* fall-through */
1381 		case EARLY_PLATFORM_ID_UNSET:
1382 			match = NULL;
1383 			break;
1384 		default:
1385 			match = early_platform_match(epdrv, match_id);
1386 		}
1387 
1388 		if (match) {
1389 			/*
1390 			 * Set up a sensible init_name to enable
1391 			 * dev_name() and others to be used before the
1392 			 * rest of the driver core is initialized.
1393 			 */
1394 			if (!match->dev.init_name && slab_is_available()) {
1395 				if (match->id != -1)
1396 					match->dev.init_name =
1397 						kasprintf(GFP_KERNEL, "%s.%d",
1398 							  match->name,
1399 							  match->id);
1400 				else
1401 					match->dev.init_name =
1402 						kasprintf(GFP_KERNEL, "%s",
1403 							  match->name);
1404 
1405 				if (!match->dev.init_name)
1406 					return -ENOMEM;
1407 			}
1408 
1409 			if (epdrv->pdrv->probe(match))
1410 				pr_warn("%s: unable to probe %s early.\n",
1411 					class_str, match->name);
1412 			else
1413 				n++;
1414 		}
1415 
1416 		if (n >= nr_probe)
1417 			break;
1418 	}
1419 
1420 	if (left)
1421 		return n;
1422 	else
1423 		return -ENODEV;
1424 }
1425 
1426 /**
1427  * early_platform_driver_probe - probe a class of registered drivers
1428  * @class_str: string to identify early platform driver class
1429  * @nr_probe: number of platform devices to successfully probe before exiting
1430  * @user_only: only probe user specified early platform devices
1431  *
1432  * Used by architecture code to probe registered early platform drivers
1433  * within a certain class. For probe to happen a registered early platform
1434  * device matching a registered early platform driver is needed.
1435  */
1436 int __init early_platform_driver_probe(char *class_str,
1437 				       int nr_probe,
1438 				       int user_only)
1439 {
1440 	int k, n, i;
1441 
1442 	n = 0;
1443 	for (i = -2; n < nr_probe; i++) {
1444 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1445 
1446 		if (k < 0)
1447 			break;
1448 
1449 		n += k;
1450 
1451 		if (user_only)
1452 			break;
1453 	}
1454 
1455 	return n;
1456 }
1457 
1458 /**
1459  * early_platform_cleanup - clean up early platform code
1460  */
1461 void __init early_platform_cleanup(void)
1462 {
1463 	struct platform_device *pd, *pd2;
1464 
1465 	/* clean up the devres list used to chain devices */
1466 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1467 				 dev.devres_head) {
1468 		list_del(&pd->dev.devres_head);
1469 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1470 	}
1471 }
1472 
1473