1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * platform.c - platform 'pseudo' bus for legacy devices
4  *
5  * Copyright (c) 2002-3 Patrick Mochel
6  * Copyright (c) 2002-3 Open Source Development Labs
7  *
8  * Please see Documentation/driver-api/driver-model/platform.rst for more
9  * information.
10  */
11 
12 #include <linux/string.h>
13 #include <linux/platform_device.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/ioport.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/memblock.h>
22 #include <linux/err.h>
23 #include <linux/slab.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/pm_domain.h>
26 #include <linux/idr.h>
27 #include <linux/acpi.h>
28 #include <linux/clk/clk-conf.h>
29 #include <linux/limits.h>
30 #include <linux/property.h>
31 #include <linux/kmemleak.h>
32 #include <linux/types.h>
33 #include <linux/iommu.h>
34 #include <linux/dma-map-ops.h>
35 
36 #include "base.h"
37 #include "power/power.h"
38 
39 /* For automatically allocated device IDs */
40 static DEFINE_IDA(platform_devid_ida);
41 
42 struct device platform_bus = {
43 	.init_name	= "platform",
44 };
45 EXPORT_SYMBOL_GPL(platform_bus);
46 
47 /**
48  * platform_get_resource - get a resource for a device
49  * @dev: platform device
50  * @type: resource type
51  * @num: resource index
52  *
53  * Return: a pointer to the resource or NULL on failure.
54  */
platform_get_resource(struct platform_device * dev,unsigned int type,unsigned int num)55 struct resource *platform_get_resource(struct platform_device *dev,
56 				       unsigned int type, unsigned int num)
57 {
58 	u32 i;
59 
60 	for (i = 0; i < dev->num_resources; i++) {
61 		struct resource *r = &dev->resource[i];
62 
63 		if (type == resource_type(r) && num-- == 0)
64 			return r;
65 	}
66 	return NULL;
67 }
68 EXPORT_SYMBOL_GPL(platform_get_resource);
69 
platform_get_mem_or_io(struct platform_device * dev,unsigned int num)70 struct resource *platform_get_mem_or_io(struct platform_device *dev,
71 					unsigned int num)
72 {
73 	u32 i;
74 
75 	for (i = 0; i < dev->num_resources; i++) {
76 		struct resource *r = &dev->resource[i];
77 
78 		if ((resource_type(r) & (IORESOURCE_MEM|IORESOURCE_IO)) && num-- == 0)
79 			return r;
80 	}
81 	return NULL;
82 }
83 EXPORT_SYMBOL_GPL(platform_get_mem_or_io);
84 
85 #ifdef CONFIG_HAS_IOMEM
86 /**
87  * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
88  *					    platform device and get resource
89  *
90  * @pdev: platform device to use both for memory resource lookup as well as
91  *        resource management
92  * @index: resource index
93  * @res: optional output parameter to store a pointer to the obtained resource.
94  *
95  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
96  * on failure.
97  */
98 void __iomem *
devm_platform_get_and_ioremap_resource(struct platform_device * pdev,unsigned int index,struct resource ** res)99 devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
100 				unsigned int index, struct resource **res)
101 {
102 	struct resource *r;
103 
104 	r = platform_get_resource(pdev, IORESOURCE_MEM, index);
105 	if (res)
106 		*res = r;
107 	return devm_ioremap_resource(&pdev->dev, r);
108 }
109 EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
110 
111 /**
112  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
113  *				    device
114  *
115  * @pdev: platform device to use both for memory resource lookup as well as
116  *        resource management
117  * @index: resource index
118  *
119  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
120  * on failure.
121  */
devm_platform_ioremap_resource(struct platform_device * pdev,unsigned int index)122 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
123 					     unsigned int index)
124 {
125 	return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
126 }
127 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
128 
129 /**
130  * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
131  *					   a platform device, retrieve the
132  *					   resource by name
133  *
134  * @pdev: platform device to use both for memory resource lookup as well as
135  *	  resource management
136  * @name: name of the resource
137  *
138  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
139  * on failure.
140  */
141 void __iomem *
devm_platform_ioremap_resource_byname(struct platform_device * pdev,const char * name)142 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
143 				      const char *name)
144 {
145 	struct resource *res;
146 
147 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
148 	return devm_ioremap_resource(&pdev->dev, res);
149 }
150 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
151 #endif /* CONFIG_HAS_IOMEM */
152 
153 /**
154  * platform_get_irq_optional - get an optional IRQ for a device
155  * @dev: platform device
156  * @num: IRQ number index
157  *
158  * Gets an IRQ for a platform device. Device drivers should check the return
159  * value for errors so as to not pass a negative integer value to the
160  * request_irq() APIs. This is the same as platform_get_irq(), except that it
161  * does not print an error message if an IRQ can not be obtained.
162  *
163  * For example::
164  *
165  *		int irq = platform_get_irq_optional(pdev, 0);
166  *		if (irq < 0)
167  *			return irq;
168  *
169  * Return: non-zero IRQ number on success, negative error number on failure.
170  */
platform_get_irq_optional(struct platform_device * dev,unsigned int num)171 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
172 {
173 	int ret;
174 #ifdef CONFIG_SPARC
175 	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
176 	if (!dev || num >= dev->archdata.num_irqs)
177 		goto out_not_found;
178 	ret = dev->archdata.irqs[num];
179 	goto out;
180 #else
181 	struct resource *r;
182 
183 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
184 		ret = of_irq_get(dev->dev.of_node, num);
185 		if (ret > 0 || ret == -EPROBE_DEFER)
186 			goto out;
187 	}
188 
189 	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
190 	if (has_acpi_companion(&dev->dev)) {
191 		if (r && r->flags & IORESOURCE_DISABLED) {
192 			ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
193 			if (ret)
194 				goto out;
195 		}
196 	}
197 
198 	/*
199 	 * The resources may pass trigger flags to the irqs that need
200 	 * to be set up. It so happens that the trigger flags for
201 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
202 	 * settings.
203 	 */
204 	if (r && r->flags & IORESOURCE_BITS) {
205 		struct irq_data *irqd;
206 
207 		irqd = irq_get_irq_data(r->start);
208 		if (!irqd)
209 			goto out_not_found;
210 		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
211 	}
212 
213 	if (r) {
214 		ret = r->start;
215 		goto out;
216 	}
217 
218 	/*
219 	 * For the index 0 interrupt, allow falling back to GpioInt
220 	 * resources. While a device could have both Interrupt and GpioInt
221 	 * resources, making this fallback ambiguous, in many common cases
222 	 * the device will only expose one IRQ, and this fallback
223 	 * allows a common code path across either kind of resource.
224 	 */
225 	if (num == 0 && has_acpi_companion(&dev->dev)) {
226 		ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
227 		/* Our callers expect -ENXIO for missing IRQs. */
228 		if (ret >= 0 || ret == -EPROBE_DEFER)
229 			goto out;
230 	}
231 
232 #endif
233 out_not_found:
234 	ret = -ENXIO;
235 out:
236 	if (WARN(!ret, "0 is an invalid IRQ number\n"))
237 		return -EINVAL;
238 	return ret;
239 }
240 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
241 
242 /**
243  * platform_get_irq - get an IRQ for a device
244  * @dev: platform device
245  * @num: IRQ number index
246  *
247  * Gets an IRQ for a platform device and prints an error message if finding the
248  * IRQ fails. Device drivers should check the return value for errors so as to
249  * not pass a negative integer value to the request_irq() APIs.
250  *
251  * For example::
252  *
253  *		int irq = platform_get_irq(pdev, 0);
254  *		if (irq < 0)
255  *			return irq;
256  *
257  * Return: non-zero IRQ number on success, negative error number on failure.
258  */
platform_get_irq(struct platform_device * dev,unsigned int num)259 int platform_get_irq(struct platform_device *dev, unsigned int num)
260 {
261 	int ret;
262 
263 	ret = platform_get_irq_optional(dev, num);
264 	if (ret < 0)
265 		return dev_err_probe(&dev->dev, ret,
266 				     "IRQ index %u not found\n", num);
267 
268 	return ret;
269 }
270 EXPORT_SYMBOL_GPL(platform_get_irq);
271 
272 /**
273  * platform_irq_count - Count the number of IRQs a platform device uses
274  * @dev: platform device
275  *
276  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
277  */
platform_irq_count(struct platform_device * dev)278 int platform_irq_count(struct platform_device *dev)
279 {
280 	int ret, nr = 0;
281 
282 	while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
283 		nr++;
284 
285 	if (ret == -EPROBE_DEFER)
286 		return ret;
287 
288 	return nr;
289 }
290 EXPORT_SYMBOL_GPL(platform_irq_count);
291 
292 struct irq_affinity_devres {
293 	unsigned int count;
294 	unsigned int irq[];
295 };
296 
platform_disable_acpi_irq(struct platform_device * pdev,int index)297 static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
298 {
299 	struct resource *r;
300 
301 	r = platform_get_resource(pdev, IORESOURCE_IRQ, index);
302 	if (r)
303 		irqresource_disabled(r, 0);
304 }
305 
devm_platform_get_irqs_affinity_release(struct device * dev,void * res)306 static void devm_platform_get_irqs_affinity_release(struct device *dev,
307 						    void *res)
308 {
309 	struct irq_affinity_devres *ptr = res;
310 	int i;
311 
312 	for (i = 0; i < ptr->count; i++) {
313 		irq_dispose_mapping(ptr->irq[i]);
314 
315 		if (has_acpi_companion(dev))
316 			platform_disable_acpi_irq(to_platform_device(dev), i);
317 	}
318 }
319 
320 /**
321  * devm_platform_get_irqs_affinity - devm method to get a set of IRQs for a
322  *				device using an interrupt affinity descriptor
323  * @dev: platform device pointer
324  * @affd: affinity descriptor
325  * @minvec: minimum count of interrupt vectors
326  * @maxvec: maximum count of interrupt vectors
327  * @irqs: pointer holder for IRQ numbers
328  *
329  * Gets a set of IRQs for a platform device, and updates IRQ afffinty according
330  * to the passed affinity descriptor
331  *
332  * Return: Number of vectors on success, negative error number on failure.
333  */
devm_platform_get_irqs_affinity(struct platform_device * dev,struct irq_affinity * affd,unsigned int minvec,unsigned int maxvec,int ** irqs)334 int devm_platform_get_irqs_affinity(struct platform_device *dev,
335 				    struct irq_affinity *affd,
336 				    unsigned int minvec,
337 				    unsigned int maxvec,
338 				    int **irqs)
339 {
340 	struct irq_affinity_devres *ptr;
341 	struct irq_affinity_desc *desc;
342 	size_t size;
343 	int i, ret, nvec;
344 
345 	if (!affd)
346 		return -EPERM;
347 
348 	if (maxvec < minvec)
349 		return -ERANGE;
350 
351 	nvec = platform_irq_count(dev);
352 	if (nvec < 0)
353 		return nvec;
354 
355 	if (nvec < minvec)
356 		return -ENOSPC;
357 
358 	nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
359 	if (nvec < minvec)
360 		return -ENOSPC;
361 
362 	if (nvec > maxvec)
363 		nvec = maxvec;
364 
365 	size = sizeof(*ptr) + sizeof(unsigned int) * nvec;
366 	ptr = devres_alloc(devm_platform_get_irqs_affinity_release, size,
367 			   GFP_KERNEL);
368 	if (!ptr)
369 		return -ENOMEM;
370 
371 	ptr->count = nvec;
372 
373 	for (i = 0; i < nvec; i++) {
374 		int irq = platform_get_irq(dev, i);
375 		if (irq < 0) {
376 			ret = irq;
377 			goto err_free_devres;
378 		}
379 		ptr->irq[i] = irq;
380 	}
381 
382 	desc = irq_create_affinity_masks(nvec, affd);
383 	if (!desc) {
384 		ret = -ENOMEM;
385 		goto err_free_devres;
386 	}
387 
388 	for (i = 0; i < nvec; i++) {
389 		ret = irq_update_affinity_desc(ptr->irq[i], &desc[i]);
390 		if (ret) {
391 			dev_err(&dev->dev, "failed to update irq%d affinity descriptor (%d)\n",
392 				ptr->irq[i], ret);
393 			goto err_free_desc;
394 		}
395 	}
396 
397 	devres_add(&dev->dev, ptr);
398 
399 	kfree(desc);
400 
401 	*irqs = ptr->irq;
402 
403 	return nvec;
404 
405 err_free_desc:
406 	kfree(desc);
407 err_free_devres:
408 	devres_free(ptr);
409 	return ret;
410 }
411 EXPORT_SYMBOL_GPL(devm_platform_get_irqs_affinity);
412 
413 /**
414  * platform_get_resource_byname - get a resource for a device by name
415  * @dev: platform device
416  * @type: resource type
417  * @name: resource name
418  */
platform_get_resource_byname(struct platform_device * dev,unsigned int type,const char * name)419 struct resource *platform_get_resource_byname(struct platform_device *dev,
420 					      unsigned int type,
421 					      const char *name)
422 {
423 	u32 i;
424 
425 	for (i = 0; i < dev->num_resources; i++) {
426 		struct resource *r = &dev->resource[i];
427 
428 		if (unlikely(!r->name))
429 			continue;
430 
431 		if (type == resource_type(r) && !strcmp(r->name, name))
432 			return r;
433 	}
434 	return NULL;
435 }
436 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
437 
__platform_get_irq_byname(struct platform_device * dev,const char * name)438 static int __platform_get_irq_byname(struct platform_device *dev,
439 				     const char *name)
440 {
441 	struct resource *r;
442 	int ret;
443 
444 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
445 		ret = of_irq_get_byname(dev->dev.of_node, name);
446 		if (ret > 0 || ret == -EPROBE_DEFER)
447 			return ret;
448 	}
449 
450 	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
451 	if (r) {
452 		if (WARN(!r->start, "0 is an invalid IRQ number\n"))
453 			return -EINVAL;
454 		return r->start;
455 	}
456 
457 	return -ENXIO;
458 }
459 
460 /**
461  * platform_get_irq_byname - get an IRQ for a device by name
462  * @dev: platform device
463  * @name: IRQ name
464  *
465  * Get an IRQ like platform_get_irq(), but then by name rather then by index.
466  *
467  * Return: non-zero IRQ number on success, negative error number on failure.
468  */
platform_get_irq_byname(struct platform_device * dev,const char * name)469 int platform_get_irq_byname(struct platform_device *dev, const char *name)
470 {
471 	int ret;
472 
473 	ret = __platform_get_irq_byname(dev, name);
474 	if (ret < 0)
475 		return dev_err_probe(&dev->dev, ret, "IRQ %s not found\n",
476 				     name);
477 	return ret;
478 }
479 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
480 
481 /**
482  * platform_get_irq_byname_optional - get an optional IRQ for a device by name
483  * @dev: platform device
484  * @name: IRQ name
485  *
486  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
487  * does not print an error message if an IRQ can not be obtained.
488  *
489  * Return: non-zero IRQ number on success, negative error number on failure.
490  */
platform_get_irq_byname_optional(struct platform_device * dev,const char * name)491 int platform_get_irq_byname_optional(struct platform_device *dev,
492 				     const char *name)
493 {
494 	return __platform_get_irq_byname(dev, name);
495 }
496 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
497 
498 /**
499  * platform_add_devices - add a numbers of platform devices
500  * @devs: array of platform devices to add
501  * @num: number of platform devices in array
502  */
platform_add_devices(struct platform_device ** devs,int num)503 int platform_add_devices(struct platform_device **devs, int num)
504 {
505 	int i, ret = 0;
506 
507 	for (i = 0; i < num; i++) {
508 		ret = platform_device_register(devs[i]);
509 		if (ret) {
510 			while (--i >= 0)
511 				platform_device_unregister(devs[i]);
512 			break;
513 		}
514 	}
515 
516 	return ret;
517 }
518 EXPORT_SYMBOL_GPL(platform_add_devices);
519 
520 struct platform_object {
521 	struct platform_device pdev;
522 	char name[];
523 };
524 
525 /*
526  * Set up default DMA mask for platform devices if the they weren't
527  * previously set by the architecture / DT.
528  */
setup_pdev_dma_masks(struct platform_device * pdev)529 static void setup_pdev_dma_masks(struct platform_device *pdev)
530 {
531 	pdev->dev.dma_parms = &pdev->dma_parms;
532 
533 	if (!pdev->dev.coherent_dma_mask)
534 		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
535 	if (!pdev->dev.dma_mask) {
536 		pdev->platform_dma_mask = DMA_BIT_MASK(32);
537 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
538 	}
539 };
540 
541 /**
542  * platform_device_put - destroy a platform device
543  * @pdev: platform device to free
544  *
545  * Free all memory associated with a platform device.  This function must
546  * _only_ be externally called in error cases.  All other usage is a bug.
547  */
platform_device_put(struct platform_device * pdev)548 void platform_device_put(struct platform_device *pdev)
549 {
550 	if (!IS_ERR_OR_NULL(pdev))
551 		put_device(&pdev->dev);
552 }
553 EXPORT_SYMBOL_GPL(platform_device_put);
554 
platform_device_release(struct device * dev)555 static void platform_device_release(struct device *dev)
556 {
557 	struct platform_object *pa = container_of(dev, struct platform_object,
558 						  pdev.dev);
559 
560 	of_node_put(pa->pdev.dev.of_node);
561 	kfree(pa->pdev.dev.platform_data);
562 	kfree(pa->pdev.mfd_cell);
563 	kfree(pa->pdev.resource);
564 	kfree(pa->pdev.driver_override);
565 	kfree(pa);
566 }
567 
568 /**
569  * platform_device_alloc - create a platform device
570  * @name: base name of the device we're adding
571  * @id: instance id
572  *
573  * Create a platform device object which can have other objects attached
574  * to it, and which will have attached objects freed when it is released.
575  */
platform_device_alloc(const char * name,int id)576 struct platform_device *platform_device_alloc(const char *name, int id)
577 {
578 	struct platform_object *pa;
579 
580 	pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
581 	if (pa) {
582 		strcpy(pa->name, name);
583 		pa->pdev.name = pa->name;
584 		pa->pdev.id = id;
585 		device_initialize(&pa->pdev.dev);
586 		pa->pdev.dev.release = platform_device_release;
587 		setup_pdev_dma_masks(&pa->pdev);
588 	}
589 
590 	return pa ? &pa->pdev : NULL;
591 }
592 EXPORT_SYMBOL_GPL(platform_device_alloc);
593 
594 /**
595  * platform_device_add_resources - add resources to a platform device
596  * @pdev: platform device allocated by platform_device_alloc to add resources to
597  * @res: set of resources that needs to be allocated for the device
598  * @num: number of resources
599  *
600  * Add a copy of the resources to the platform device.  The memory
601  * associated with the resources will be freed when the platform device is
602  * released.
603  */
platform_device_add_resources(struct platform_device * pdev,const struct resource * res,unsigned int num)604 int platform_device_add_resources(struct platform_device *pdev,
605 				  const struct resource *res, unsigned int num)
606 {
607 	struct resource *r = NULL;
608 
609 	if (res) {
610 		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
611 		if (!r)
612 			return -ENOMEM;
613 	}
614 
615 	kfree(pdev->resource);
616 	pdev->resource = r;
617 	pdev->num_resources = num;
618 	return 0;
619 }
620 EXPORT_SYMBOL_GPL(platform_device_add_resources);
621 
622 /**
623  * platform_device_add_data - add platform-specific data to a platform device
624  * @pdev: platform device allocated by platform_device_alloc to add resources to
625  * @data: platform specific data for this platform device
626  * @size: size of platform specific data
627  *
628  * Add a copy of platform specific data to the platform device's
629  * platform_data pointer.  The memory associated with the platform data
630  * will be freed when the platform device is released.
631  */
platform_device_add_data(struct platform_device * pdev,const void * data,size_t size)632 int platform_device_add_data(struct platform_device *pdev, const void *data,
633 			     size_t size)
634 {
635 	void *d = NULL;
636 
637 	if (data) {
638 		d = kmemdup(data, size, GFP_KERNEL);
639 		if (!d)
640 			return -ENOMEM;
641 	}
642 
643 	kfree(pdev->dev.platform_data);
644 	pdev->dev.platform_data = d;
645 	return 0;
646 }
647 EXPORT_SYMBOL_GPL(platform_device_add_data);
648 
649 /**
650  * platform_device_add - add a platform device to device hierarchy
651  * @pdev: platform device we're adding
652  *
653  * This is part 2 of platform_device_register(), though may be called
654  * separately _iff_ pdev was allocated by platform_device_alloc().
655  */
platform_device_add(struct platform_device * pdev)656 int platform_device_add(struct platform_device *pdev)
657 {
658 	u32 i;
659 	int ret;
660 
661 	if (!pdev)
662 		return -EINVAL;
663 
664 	if (!pdev->dev.parent)
665 		pdev->dev.parent = &platform_bus;
666 
667 	pdev->dev.bus = &platform_bus_type;
668 
669 	switch (pdev->id) {
670 	default:
671 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
672 		break;
673 	case PLATFORM_DEVID_NONE:
674 		dev_set_name(&pdev->dev, "%s", pdev->name);
675 		break;
676 	case PLATFORM_DEVID_AUTO:
677 		/*
678 		 * Automatically allocated device ID. We mark it as such so
679 		 * that we remember it must be freed, and we append a suffix
680 		 * to avoid namespace collision with explicit IDs.
681 		 */
682 		ret = ida_alloc(&platform_devid_ida, GFP_KERNEL);
683 		if (ret < 0)
684 			goto err_out;
685 		pdev->id = ret;
686 		pdev->id_auto = true;
687 		dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
688 		break;
689 	}
690 
691 	for (i = 0; i < pdev->num_resources; i++) {
692 		struct resource *p, *r = &pdev->resource[i];
693 
694 		if (r->name == NULL)
695 			r->name = dev_name(&pdev->dev);
696 
697 		p = r->parent;
698 		if (!p) {
699 			if (resource_type(r) == IORESOURCE_MEM)
700 				p = &iomem_resource;
701 			else if (resource_type(r) == IORESOURCE_IO)
702 				p = &ioport_resource;
703 		}
704 
705 		if (p) {
706 			ret = insert_resource(p, r);
707 			if (ret) {
708 				dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
709 				goto failed;
710 			}
711 		}
712 	}
713 
714 	pr_debug("Registering platform device '%s'. Parent at %s\n",
715 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
716 
717 	ret = device_add(&pdev->dev);
718 	if (ret == 0)
719 		return ret;
720 
721  failed:
722 	if (pdev->id_auto) {
723 		ida_free(&platform_devid_ida, pdev->id);
724 		pdev->id = PLATFORM_DEVID_AUTO;
725 	}
726 
727 	while (i--) {
728 		struct resource *r = &pdev->resource[i];
729 		if (r->parent)
730 			release_resource(r);
731 	}
732 
733  err_out:
734 	return ret;
735 }
736 EXPORT_SYMBOL_GPL(platform_device_add);
737 
738 /**
739  * platform_device_del - remove a platform-level device
740  * @pdev: platform device we're removing
741  *
742  * Note that this function will also release all memory- and port-based
743  * resources owned by the device (@dev->resource).  This function must
744  * _only_ be externally called in error cases.  All other usage is a bug.
745  */
platform_device_del(struct platform_device * pdev)746 void platform_device_del(struct platform_device *pdev)
747 {
748 	u32 i;
749 
750 	if (!IS_ERR_OR_NULL(pdev)) {
751 		device_del(&pdev->dev);
752 
753 		if (pdev->id_auto) {
754 			ida_free(&platform_devid_ida, pdev->id);
755 			pdev->id = PLATFORM_DEVID_AUTO;
756 		}
757 
758 		for (i = 0; i < pdev->num_resources; i++) {
759 			struct resource *r = &pdev->resource[i];
760 			if (r->parent)
761 				release_resource(r);
762 		}
763 	}
764 }
765 EXPORT_SYMBOL_GPL(platform_device_del);
766 
767 /**
768  * platform_device_register - add a platform-level device
769  * @pdev: platform device we're adding
770  *
771  * NOTE: _Never_ directly free @pdev after calling this function, even if it
772  * returned an error! Always use platform_device_put() to give up the
773  * reference initialised in this function instead.
774  */
platform_device_register(struct platform_device * pdev)775 int platform_device_register(struct platform_device *pdev)
776 {
777 	device_initialize(&pdev->dev);
778 	setup_pdev_dma_masks(pdev);
779 	return platform_device_add(pdev);
780 }
781 EXPORT_SYMBOL_GPL(platform_device_register);
782 
783 /**
784  * platform_device_unregister - unregister a platform-level device
785  * @pdev: platform device we're unregistering
786  *
787  * Unregistration is done in 2 steps. First we release all resources
788  * and remove it from the subsystem, then we drop reference count by
789  * calling platform_device_put().
790  */
platform_device_unregister(struct platform_device * pdev)791 void platform_device_unregister(struct platform_device *pdev)
792 {
793 	platform_device_del(pdev);
794 	platform_device_put(pdev);
795 }
796 EXPORT_SYMBOL_GPL(platform_device_unregister);
797 
798 /**
799  * platform_device_register_full - add a platform-level device with
800  * resources and platform-specific data
801  *
802  * @pdevinfo: data used to create device
803  *
804  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
805  */
platform_device_register_full(const struct platform_device_info * pdevinfo)806 struct platform_device *platform_device_register_full(
807 		const struct platform_device_info *pdevinfo)
808 {
809 	int ret;
810 	struct platform_device *pdev;
811 
812 	pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
813 	if (!pdev)
814 		return ERR_PTR(-ENOMEM);
815 
816 	pdev->dev.parent = pdevinfo->parent;
817 	pdev->dev.fwnode = pdevinfo->fwnode;
818 	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
819 	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
820 
821 	if (pdevinfo->dma_mask) {
822 		pdev->platform_dma_mask = pdevinfo->dma_mask;
823 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
824 		pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
825 	}
826 
827 	ret = platform_device_add_resources(pdev,
828 			pdevinfo->res, pdevinfo->num_res);
829 	if (ret)
830 		goto err;
831 
832 	ret = platform_device_add_data(pdev,
833 			pdevinfo->data, pdevinfo->size_data);
834 	if (ret)
835 		goto err;
836 
837 	if (pdevinfo->properties) {
838 		ret = device_create_managed_software_node(&pdev->dev,
839 							  pdevinfo->properties, NULL);
840 		if (ret)
841 			goto err;
842 	}
843 
844 	ret = platform_device_add(pdev);
845 	if (ret) {
846 err:
847 		ACPI_COMPANION_SET(&pdev->dev, NULL);
848 		platform_device_put(pdev);
849 		return ERR_PTR(ret);
850 	}
851 
852 	return pdev;
853 }
854 EXPORT_SYMBOL_GPL(platform_device_register_full);
855 
856 /**
857  * __platform_driver_register - register a driver for platform-level devices
858  * @drv: platform driver structure
859  * @owner: owning module/driver
860  */
__platform_driver_register(struct platform_driver * drv,struct module * owner)861 int __platform_driver_register(struct platform_driver *drv,
862 				struct module *owner)
863 {
864 	drv->driver.owner = owner;
865 	drv->driver.bus = &platform_bus_type;
866 
867 	return driver_register(&drv->driver);
868 }
869 EXPORT_SYMBOL_GPL(__platform_driver_register);
870 
871 /**
872  * platform_driver_unregister - unregister a driver for platform-level devices
873  * @drv: platform driver structure
874  */
platform_driver_unregister(struct platform_driver * drv)875 void platform_driver_unregister(struct platform_driver *drv)
876 {
877 	driver_unregister(&drv->driver);
878 }
879 EXPORT_SYMBOL_GPL(platform_driver_unregister);
880 
platform_probe_fail(struct platform_device * pdev)881 static int platform_probe_fail(struct platform_device *pdev)
882 {
883 	return -ENXIO;
884 }
885 
886 /**
887  * __platform_driver_probe - register driver for non-hotpluggable device
888  * @drv: platform driver structure
889  * @probe: the driver probe routine, probably from an __init section
890  * @module: module which will be the owner of the driver
891  *
892  * Use this instead of platform_driver_register() when you know the device
893  * is not hotpluggable and has already been registered, and you want to
894  * remove its run-once probe() infrastructure from memory after the driver
895  * has bound to the device.
896  *
897  * One typical use for this would be with drivers for controllers integrated
898  * into system-on-chip processors, where the controller devices have been
899  * configured as part of board setup.
900  *
901  * Note that this is incompatible with deferred probing.
902  *
903  * Returns zero if the driver registered and bound to a device, else returns
904  * a negative error code and with the driver not registered.
905  */
__platform_driver_probe(struct platform_driver * drv,int (* probe)(struct platform_device *),struct module * module)906 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
907 		int (*probe)(struct platform_device *), struct module *module)
908 {
909 	int retval, code;
910 
911 	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
912 		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
913 			 drv->driver.name, __func__);
914 		return -EINVAL;
915 	}
916 
917 	/*
918 	 * We have to run our probes synchronously because we check if
919 	 * we find any devices to bind to and exit with error if there
920 	 * are any.
921 	 */
922 	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
923 
924 	/*
925 	 * Prevent driver from requesting probe deferral to avoid further
926 	 * futile probe attempts.
927 	 */
928 	drv->prevent_deferred_probe = true;
929 
930 	/* make sure driver won't have bind/unbind attributes */
931 	drv->driver.suppress_bind_attrs = true;
932 
933 	/* temporary section violation during probe() */
934 	drv->probe = probe;
935 	retval = code = __platform_driver_register(drv, module);
936 	if (retval)
937 		return retval;
938 
939 	/*
940 	 * Fixup that section violation, being paranoid about code scanning
941 	 * the list of drivers in order to probe new devices.  Check to see
942 	 * if the probe was successful, and make sure any forced probes of
943 	 * new devices fail.
944 	 */
945 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
946 	drv->probe = platform_probe_fail;
947 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
948 		retval = -ENODEV;
949 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
950 
951 	if (code != retval)
952 		platform_driver_unregister(drv);
953 	return retval;
954 }
955 EXPORT_SYMBOL_GPL(__platform_driver_probe);
956 
957 /**
958  * __platform_create_bundle - register driver and create corresponding device
959  * @driver: platform driver structure
960  * @probe: the driver probe routine, probably from an __init section
961  * @res: set of resources that needs to be allocated for the device
962  * @n_res: number of resources
963  * @data: platform specific data for this platform device
964  * @size: size of platform specific data
965  * @module: module which will be the owner of the driver
966  *
967  * Use this in legacy-style modules that probe hardware directly and
968  * register a single platform device and corresponding platform driver.
969  *
970  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
971  */
__platform_create_bundle(struct platform_driver * driver,int (* probe)(struct platform_device *),struct resource * res,unsigned int n_res,const void * data,size_t size,struct module * module)972 struct platform_device * __init_or_module __platform_create_bundle(
973 			struct platform_driver *driver,
974 			int (*probe)(struct platform_device *),
975 			struct resource *res, unsigned int n_res,
976 			const void *data, size_t size, struct module *module)
977 {
978 	struct platform_device *pdev;
979 	int error;
980 
981 	pdev = platform_device_alloc(driver->driver.name, -1);
982 	if (!pdev) {
983 		error = -ENOMEM;
984 		goto err_out;
985 	}
986 
987 	error = platform_device_add_resources(pdev, res, n_res);
988 	if (error)
989 		goto err_pdev_put;
990 
991 	error = platform_device_add_data(pdev, data, size);
992 	if (error)
993 		goto err_pdev_put;
994 
995 	error = platform_device_add(pdev);
996 	if (error)
997 		goto err_pdev_put;
998 
999 	error = __platform_driver_probe(driver, probe, module);
1000 	if (error)
1001 		goto err_pdev_del;
1002 
1003 	return pdev;
1004 
1005 err_pdev_del:
1006 	platform_device_del(pdev);
1007 err_pdev_put:
1008 	platform_device_put(pdev);
1009 err_out:
1010 	return ERR_PTR(error);
1011 }
1012 EXPORT_SYMBOL_GPL(__platform_create_bundle);
1013 
1014 /**
1015  * __platform_register_drivers - register an array of platform drivers
1016  * @drivers: an array of drivers to register
1017  * @count: the number of drivers to register
1018  * @owner: module owning the drivers
1019  *
1020  * Registers platform drivers specified by an array. On failure to register a
1021  * driver, all previously registered drivers will be unregistered. Callers of
1022  * this API should use platform_unregister_drivers() to unregister drivers in
1023  * the reverse order.
1024  *
1025  * Returns: 0 on success or a negative error code on failure.
1026  */
__platform_register_drivers(struct platform_driver * const * drivers,unsigned int count,struct module * owner)1027 int __platform_register_drivers(struct platform_driver * const *drivers,
1028 				unsigned int count, struct module *owner)
1029 {
1030 	unsigned int i;
1031 	int err;
1032 
1033 	for (i = 0; i < count; i++) {
1034 		pr_debug("registering platform driver %ps\n", drivers[i]);
1035 
1036 		err = __platform_driver_register(drivers[i], owner);
1037 		if (err < 0) {
1038 			pr_err("failed to register platform driver %ps: %d\n",
1039 			       drivers[i], err);
1040 			goto error;
1041 		}
1042 	}
1043 
1044 	return 0;
1045 
1046 error:
1047 	while (i--) {
1048 		pr_debug("unregistering platform driver %ps\n", drivers[i]);
1049 		platform_driver_unregister(drivers[i]);
1050 	}
1051 
1052 	return err;
1053 }
1054 EXPORT_SYMBOL_GPL(__platform_register_drivers);
1055 
1056 /**
1057  * platform_unregister_drivers - unregister an array of platform drivers
1058  * @drivers: an array of drivers to unregister
1059  * @count: the number of drivers to unregister
1060  *
1061  * Unregisters platform drivers specified by an array. This is typically used
1062  * to complement an earlier call to platform_register_drivers(). Drivers are
1063  * unregistered in the reverse order in which they were registered.
1064  */
platform_unregister_drivers(struct platform_driver * const * drivers,unsigned int count)1065 void platform_unregister_drivers(struct platform_driver * const *drivers,
1066 				 unsigned int count)
1067 {
1068 	while (count--) {
1069 		pr_debug("unregistering platform driver %ps\n", drivers[count]);
1070 		platform_driver_unregister(drivers[count]);
1071 	}
1072 }
1073 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1074 
platform_match_id(const struct platform_device_id * id,struct platform_device * pdev)1075 static const struct platform_device_id *platform_match_id(
1076 			const struct platform_device_id *id,
1077 			struct platform_device *pdev)
1078 {
1079 	while (id->name[0]) {
1080 		if (strcmp(pdev->name, id->name) == 0) {
1081 			pdev->id_entry = id;
1082 			return id;
1083 		}
1084 		id++;
1085 	}
1086 	return NULL;
1087 }
1088 
1089 #ifdef CONFIG_PM_SLEEP
1090 
platform_legacy_suspend(struct device * dev,pm_message_t mesg)1091 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1092 {
1093 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1094 	struct platform_device *pdev = to_platform_device(dev);
1095 	int ret = 0;
1096 
1097 	if (dev->driver && pdrv->suspend)
1098 		ret = pdrv->suspend(pdev, mesg);
1099 
1100 	return ret;
1101 }
1102 
platform_legacy_resume(struct device * dev)1103 static int platform_legacy_resume(struct device *dev)
1104 {
1105 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1106 	struct platform_device *pdev = to_platform_device(dev);
1107 	int ret = 0;
1108 
1109 	if (dev->driver && pdrv->resume)
1110 		ret = pdrv->resume(pdev);
1111 
1112 	return ret;
1113 }
1114 
1115 #endif /* CONFIG_PM_SLEEP */
1116 
1117 #ifdef CONFIG_SUSPEND
1118 
platform_pm_suspend(struct device * dev)1119 int platform_pm_suspend(struct device *dev)
1120 {
1121 	struct device_driver *drv = dev->driver;
1122 	int ret = 0;
1123 
1124 	if (!drv)
1125 		return 0;
1126 
1127 	if (drv->pm) {
1128 		if (drv->pm->suspend)
1129 			ret = drv->pm->suspend(dev);
1130 	} else {
1131 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1132 	}
1133 
1134 	return ret;
1135 }
1136 
platform_pm_resume(struct device * dev)1137 int platform_pm_resume(struct device *dev)
1138 {
1139 	struct device_driver *drv = dev->driver;
1140 	int ret = 0;
1141 
1142 	if (!drv)
1143 		return 0;
1144 
1145 	if (drv->pm) {
1146 		if (drv->pm->resume)
1147 			ret = drv->pm->resume(dev);
1148 	} else {
1149 		ret = platform_legacy_resume(dev);
1150 	}
1151 
1152 	return ret;
1153 }
1154 
1155 #endif /* CONFIG_SUSPEND */
1156 
1157 #ifdef CONFIG_HIBERNATE_CALLBACKS
1158 
platform_pm_freeze(struct device * dev)1159 int platform_pm_freeze(struct device *dev)
1160 {
1161 	struct device_driver *drv = dev->driver;
1162 	int ret = 0;
1163 
1164 	if (!drv)
1165 		return 0;
1166 
1167 	if (drv->pm) {
1168 		if (drv->pm->freeze)
1169 			ret = drv->pm->freeze(dev);
1170 	} else {
1171 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1172 	}
1173 
1174 	return ret;
1175 }
1176 
platform_pm_thaw(struct device * dev)1177 int platform_pm_thaw(struct device *dev)
1178 {
1179 	struct device_driver *drv = dev->driver;
1180 	int ret = 0;
1181 
1182 	if (!drv)
1183 		return 0;
1184 
1185 	if (drv->pm) {
1186 		if (drv->pm->thaw)
1187 			ret = drv->pm->thaw(dev);
1188 	} else {
1189 		ret = platform_legacy_resume(dev);
1190 	}
1191 
1192 	return ret;
1193 }
1194 
platform_pm_poweroff(struct device * dev)1195 int platform_pm_poweroff(struct device *dev)
1196 {
1197 	struct device_driver *drv = dev->driver;
1198 	int ret = 0;
1199 
1200 	if (!drv)
1201 		return 0;
1202 
1203 	if (drv->pm) {
1204 		if (drv->pm->poweroff)
1205 			ret = drv->pm->poweroff(dev);
1206 	} else {
1207 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1208 	}
1209 
1210 	return ret;
1211 }
1212 
platform_pm_restore(struct device * dev)1213 int platform_pm_restore(struct device *dev)
1214 {
1215 	struct device_driver *drv = dev->driver;
1216 	int ret = 0;
1217 
1218 	if (!drv)
1219 		return 0;
1220 
1221 	if (drv->pm) {
1222 		if (drv->pm->restore)
1223 			ret = drv->pm->restore(dev);
1224 	} else {
1225 		ret = platform_legacy_resume(dev);
1226 	}
1227 
1228 	return ret;
1229 }
1230 
1231 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1232 
1233 /* modalias support enables more hands-off userspace setup:
1234  * (a) environment variable lets new-style hotplug events work once system is
1235  *     fully running:  "modprobe $MODALIAS"
1236  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
1237  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
1238  */
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)1239 static ssize_t modalias_show(struct device *dev,
1240 			     struct device_attribute *attr, char *buf)
1241 {
1242 	struct platform_device *pdev = to_platform_device(dev);
1243 	int len;
1244 
1245 	len = of_device_modalias(dev, buf, PAGE_SIZE);
1246 	if (len != -ENODEV)
1247 		return len;
1248 
1249 	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
1250 	if (len != -ENODEV)
1251 		return len;
1252 
1253 	return sysfs_emit(buf, "platform:%s\n", pdev->name);
1254 }
1255 static DEVICE_ATTR_RO(modalias);
1256 
numa_node_show(struct device * dev,struct device_attribute * attr,char * buf)1257 static ssize_t numa_node_show(struct device *dev,
1258 			      struct device_attribute *attr, char *buf)
1259 {
1260 	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
1261 }
1262 static DEVICE_ATTR_RO(numa_node);
1263 
driver_override_show(struct device * dev,struct device_attribute * attr,char * buf)1264 static ssize_t driver_override_show(struct device *dev,
1265 				    struct device_attribute *attr, char *buf)
1266 {
1267 	struct platform_device *pdev = to_platform_device(dev);
1268 	ssize_t len;
1269 
1270 	device_lock(dev);
1271 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
1272 	device_unlock(dev);
1273 
1274 	return len;
1275 }
1276 
driver_override_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1277 static ssize_t driver_override_store(struct device *dev,
1278 				     struct device_attribute *attr,
1279 				     const char *buf, size_t count)
1280 {
1281 	struct platform_device *pdev = to_platform_device(dev);
1282 	int ret;
1283 
1284 	ret = driver_set_override(dev, &pdev->driver_override, buf, count);
1285 	if (ret)
1286 		return ret;
1287 
1288 	return count;
1289 }
1290 static DEVICE_ATTR_RW(driver_override);
1291 
1292 static struct attribute *platform_dev_attrs[] = {
1293 	&dev_attr_modalias.attr,
1294 	&dev_attr_numa_node.attr,
1295 	&dev_attr_driver_override.attr,
1296 	NULL,
1297 };
1298 
platform_dev_attrs_visible(struct kobject * kobj,struct attribute * a,int n)1299 static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a,
1300 		int n)
1301 {
1302 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
1303 
1304 	if (a == &dev_attr_numa_node.attr &&
1305 			dev_to_node(dev) == NUMA_NO_NODE)
1306 		return 0;
1307 
1308 	return a->mode;
1309 }
1310 
1311 static const struct attribute_group platform_dev_group = {
1312 	.attrs = platform_dev_attrs,
1313 	.is_visible = platform_dev_attrs_visible,
1314 };
1315 __ATTRIBUTE_GROUPS(platform_dev);
1316 
1317 
1318 /**
1319  * platform_match - bind platform device to platform driver.
1320  * @dev: device.
1321  * @drv: driver.
1322  *
1323  * Platform device IDs are assumed to be encoded like this:
1324  * "<name><instance>", where <name> is a short description of the type of
1325  * device, like "pci" or "floppy", and <instance> is the enumerated
1326  * instance of the device, like '0' or '42'.  Driver IDs are simply
1327  * "<name>".  So, extract the <name> from the platform_device structure,
1328  * and compare it against the name of the driver. Return whether they match
1329  * or not.
1330  */
platform_match(struct device * dev,struct device_driver * drv)1331 static int platform_match(struct device *dev, struct device_driver *drv)
1332 {
1333 	struct platform_device *pdev = to_platform_device(dev);
1334 	struct platform_driver *pdrv = to_platform_driver(drv);
1335 
1336 	/* When driver_override is set, only bind to the matching driver */
1337 	if (pdev->driver_override)
1338 		return !strcmp(pdev->driver_override, drv->name);
1339 
1340 	/* Attempt an OF style match first */
1341 	if (of_driver_match_device(dev, drv))
1342 		return 1;
1343 
1344 	/* Then try ACPI style match */
1345 	if (acpi_driver_match_device(dev, drv))
1346 		return 1;
1347 
1348 	/* Then try to match against the id table */
1349 	if (pdrv->id_table)
1350 		return platform_match_id(pdrv->id_table, pdev) != NULL;
1351 
1352 	/* fall-back to driver name match */
1353 	return (strcmp(pdev->name, drv->name) == 0);
1354 }
1355 
platform_uevent(struct device * dev,struct kobj_uevent_env * env)1356 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1357 {
1358 	struct platform_device	*pdev = to_platform_device(dev);
1359 	int rc;
1360 
1361 	/* Some devices have extra OF data and an OF-style MODALIAS */
1362 	rc = of_device_uevent_modalias(dev, env);
1363 	if (rc != -ENODEV)
1364 		return rc;
1365 
1366 	rc = acpi_device_uevent_modalias(dev, env);
1367 	if (rc != -ENODEV)
1368 		return rc;
1369 
1370 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1371 			pdev->name);
1372 	return 0;
1373 }
1374 
platform_probe(struct device * _dev)1375 static int platform_probe(struct device *_dev)
1376 {
1377 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1378 	struct platform_device *dev = to_platform_device(_dev);
1379 	int ret;
1380 
1381 	/*
1382 	 * A driver registered using platform_driver_probe() cannot be bound
1383 	 * again later because the probe function usually lives in __init code
1384 	 * and so is gone. For these drivers .probe is set to
1385 	 * platform_probe_fail in __platform_driver_probe(). Don't even prepare
1386 	 * clocks and PM domains for these to match the traditional behaviour.
1387 	 */
1388 	if (unlikely(drv->probe == platform_probe_fail))
1389 		return -ENXIO;
1390 
1391 	ret = of_clk_set_defaults(_dev->of_node, false);
1392 	if (ret < 0)
1393 		return ret;
1394 
1395 	ret = dev_pm_domain_attach(_dev, true);
1396 	if (ret)
1397 		goto out;
1398 
1399 	if (drv->probe) {
1400 		ret = drv->probe(dev);
1401 		if (ret)
1402 			dev_pm_domain_detach(_dev, true);
1403 	}
1404 
1405 out:
1406 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
1407 		dev_warn(_dev, "probe deferral not supported\n");
1408 		ret = -ENXIO;
1409 	}
1410 
1411 	return ret;
1412 }
1413 
platform_remove(struct device * _dev)1414 static void platform_remove(struct device *_dev)
1415 {
1416 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1417 	struct platform_device *dev = to_platform_device(_dev);
1418 
1419 	if (drv->remove) {
1420 		int ret = drv->remove(dev);
1421 
1422 		if (ret)
1423 			dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n");
1424 	}
1425 	dev_pm_domain_detach(_dev, true);
1426 }
1427 
platform_shutdown(struct device * _dev)1428 static void platform_shutdown(struct device *_dev)
1429 {
1430 	struct platform_device *dev = to_platform_device(_dev);
1431 	struct platform_driver *drv;
1432 
1433 	if (!_dev->driver)
1434 		return;
1435 
1436 	drv = to_platform_driver(_dev->driver);
1437 	if (drv->shutdown)
1438 		drv->shutdown(dev);
1439 }
1440 
platform_dma_configure(struct device * dev)1441 static int platform_dma_configure(struct device *dev)
1442 {
1443 	struct platform_driver *drv = to_platform_driver(dev->driver);
1444 	enum dev_dma_attr attr;
1445 	int ret = 0;
1446 
1447 	if (dev->of_node) {
1448 		ret = of_dma_configure(dev, dev->of_node, true);
1449 	} else if (has_acpi_companion(dev)) {
1450 		attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1451 		ret = acpi_dma_configure(dev, attr);
1452 	}
1453 
1454 	if (!ret && !drv->driver_managed_dma) {
1455 		ret = iommu_device_use_default_domain(dev);
1456 		if (ret)
1457 			arch_teardown_dma_ops(dev);
1458 	}
1459 
1460 	return ret;
1461 }
1462 
platform_dma_cleanup(struct device * dev)1463 static void platform_dma_cleanup(struct device *dev)
1464 {
1465 	struct platform_driver *drv = to_platform_driver(dev->driver);
1466 
1467 	if (!drv->driver_managed_dma)
1468 		iommu_device_unuse_default_domain(dev);
1469 }
1470 
1471 static const struct dev_pm_ops platform_dev_pm_ops = {
1472 	SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL)
1473 	USE_PLATFORM_PM_SLEEP_OPS
1474 };
1475 
1476 struct bus_type platform_bus_type = {
1477 	.name		= "platform",
1478 	.dev_groups	= platform_dev_groups,
1479 	.match		= platform_match,
1480 	.uevent		= platform_uevent,
1481 	.probe		= platform_probe,
1482 	.remove		= platform_remove,
1483 	.shutdown	= platform_shutdown,
1484 	.dma_configure	= platform_dma_configure,
1485 	.dma_cleanup	= platform_dma_cleanup,
1486 	.pm		= &platform_dev_pm_ops,
1487 };
1488 EXPORT_SYMBOL_GPL(platform_bus_type);
1489 
__platform_match(struct device * dev,const void * drv)1490 static inline int __platform_match(struct device *dev, const void *drv)
1491 {
1492 	return platform_match(dev, (struct device_driver *)drv);
1493 }
1494 
1495 /**
1496  * platform_find_device_by_driver - Find a platform device with a given
1497  * driver.
1498  * @start: The device to start the search from.
1499  * @drv: The device driver to look for.
1500  */
platform_find_device_by_driver(struct device * start,const struct device_driver * drv)1501 struct device *platform_find_device_by_driver(struct device *start,
1502 					      const struct device_driver *drv)
1503 {
1504 	return bus_find_device(&platform_bus_type, start, drv,
1505 			       __platform_match);
1506 }
1507 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1508 
early_platform_cleanup(void)1509 void __weak __init early_platform_cleanup(void) { }
1510 
platform_bus_init(void)1511 int __init platform_bus_init(void)
1512 {
1513 	int error;
1514 
1515 	early_platform_cleanup();
1516 
1517 	error = device_register(&platform_bus);
1518 	if (error) {
1519 		put_device(&platform_bus);
1520 		return error;
1521 	}
1522 	error =  bus_register(&platform_bus_type);
1523 	if (error)
1524 		device_unregister(&platform_bus);
1525 	of_platform_register_reconfig_notifier();
1526 	return error;
1527 }
1528