2 * platform.c - platform 'pseudo' bus for legacy devices
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
7 * This file is released under the GPLv2
9 * Please see Documentation/driver-model/platform.txt for more
13 #include <linux/string.h>
14 #include <linux/platform_device.h>
15 #include <linux/of_device.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/bootmem.h>
20 #include <linux/err.h>
21 #include <linux/slab.h>
22 #include <linux/pm_runtime.h>
26 #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \
29 struct device platform_bus = {
30 .init_name = "platform",
32 EXPORT_SYMBOL_GPL(platform_bus);
35 * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
36 * @pdev: platform device
38 * This is called before platform_device_add() such that any pdev_archdata may
39 * be setup before the platform_notifier is called. So if a user needs to
40 * manipulate any relevant information in the pdev_archdata they can do:
42 * platform_devic_alloc()
44 * platform_device_add()
46 * And if they don't care they can just call platform_device_register() and
47 * everything will just work out.
49 void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
54 * platform_get_resource - get a resource for a device
55 * @dev: platform device
56 * @type: resource type
57 * @num: resource index
59 struct resource *platform_get_resource(struct platform_device *dev,
60 unsigned int type, unsigned int num)
64 for (i = 0; i < dev->num_resources; i++) {
65 struct resource *r = &dev->resource[i];
67 if (type == resource_type(r) && num-- == 0)
72 EXPORT_SYMBOL_GPL(platform_get_resource);
75 * platform_get_irq - get an IRQ for a device
76 * @dev: platform device
77 * @num: IRQ number index
79 int platform_get_irq(struct platform_device *dev, unsigned int num)
81 struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
83 return r ? r->start : -ENXIO;
85 EXPORT_SYMBOL_GPL(platform_get_irq);
88 * platform_get_resource_byname - get a resource for a device by name
89 * @dev: platform device
90 * @type: resource type
91 * @name: resource name
93 struct resource *platform_get_resource_byname(struct platform_device *dev,
99 for (i = 0; i < dev->num_resources; i++) {
100 struct resource *r = &dev->resource[i];
102 if (type == resource_type(r) && !strcmp(r->name, name))
107 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
110 * platform_get_irq - get an IRQ for a device
111 * @dev: platform device
114 int platform_get_irq_byname(struct platform_device *dev, const char *name)
116 struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
119 return r ? r->start : -ENXIO;
121 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
124 * platform_add_devices - add a numbers of platform devices
125 * @devs: array of platform devices to add
126 * @num: number of platform devices in array
128 int platform_add_devices(struct platform_device **devs, int num)
132 for (i = 0; i < num; i++) {
133 ret = platform_device_register(devs[i]);
136 platform_device_unregister(devs[i]);
143 EXPORT_SYMBOL_GPL(platform_add_devices);
145 struct platform_object {
146 struct platform_device pdev;
151 * platform_device_put - destroy a platform device
152 * @pdev: platform device to free
154 * Free all memory associated with a platform device. This function must
155 * _only_ be externally called in error cases. All other usage is a bug.
157 void platform_device_put(struct platform_device *pdev)
160 put_device(&pdev->dev);
162 EXPORT_SYMBOL_GPL(platform_device_put);
164 static void platform_device_release(struct device *dev)
166 struct platform_object *pa = container_of(dev, struct platform_object,
169 of_device_node_put(&pa->pdev.dev);
170 kfree(pa->pdev.dev.platform_data);
171 kfree(pa->pdev.mfd_cell);
172 kfree(pa->pdev.resource);
177 * platform_device_alloc - create a platform device
178 * @name: base name of the device we're adding
181 * Create a platform device object which can have other objects attached
182 * to it, and which will have attached objects freed when it is released.
184 struct platform_device *platform_device_alloc(const char *name, int id)
186 struct platform_object *pa;
188 pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
190 strcpy(pa->name, name);
191 pa->pdev.name = pa->name;
193 device_initialize(&pa->pdev.dev);
194 pa->pdev.dev.release = platform_device_release;
195 arch_setup_pdev_archdata(&pa->pdev);
198 return pa ? &pa->pdev : NULL;
200 EXPORT_SYMBOL_GPL(platform_device_alloc);
203 * platform_device_add_resources - add resources to a platform device
204 * @pdev: platform device allocated by platform_device_alloc to add resources to
205 * @res: set of resources that needs to be allocated for the device
206 * @num: number of resources
208 * Add a copy of the resources to the platform device. The memory
209 * associated with the resources will be freed when the platform device is
212 int platform_device_add_resources(struct platform_device *pdev,
213 const struct resource *res, unsigned int num)
215 struct resource *r = NULL;
218 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
223 kfree(pdev->resource);
225 pdev->num_resources = num;
228 EXPORT_SYMBOL_GPL(platform_device_add_resources);
231 * platform_device_add_data - add platform-specific data to a platform device
232 * @pdev: platform device allocated by platform_device_alloc to add resources to
233 * @data: platform specific data for this platform device
234 * @size: size of platform specific data
236 * Add a copy of platform specific data to the platform device's
237 * platform_data pointer. The memory associated with the platform data
238 * will be freed when the platform device is released.
240 int platform_device_add_data(struct platform_device *pdev, const void *data,
246 d = kmemdup(data, size, GFP_KERNEL);
251 kfree(pdev->dev.platform_data);
252 pdev->dev.platform_data = d;
255 EXPORT_SYMBOL_GPL(platform_device_add_data);
258 * platform_device_add - add a platform device to device hierarchy
259 * @pdev: platform device we're adding
261 * This is part 2 of platform_device_register(), though may be called
262 * separately _iff_ pdev was allocated by platform_device_alloc().
264 int platform_device_add(struct platform_device *pdev)
271 if (!pdev->dev.parent)
272 pdev->dev.parent = &platform_bus;
274 pdev->dev.bus = &platform_bus_type;
277 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
279 dev_set_name(&pdev->dev, "%s", pdev->name);
281 for (i = 0; i < pdev->num_resources; i++) {
282 struct resource *p, *r = &pdev->resource[i];
285 r->name = dev_name(&pdev->dev);
289 if (resource_type(r) == IORESOURCE_MEM)
291 else if (resource_type(r) == IORESOURCE_IO)
292 p = &ioport_resource;
295 if (p && insert_resource(p, r)) {
297 "%s: failed to claim resource %d\n",
298 dev_name(&pdev->dev), i);
304 pr_debug("Registering platform device '%s'. Parent at %s\n",
305 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
307 ret = device_add(&pdev->dev);
313 struct resource *r = &pdev->resource[i];
320 EXPORT_SYMBOL_GPL(platform_device_add);
323 * platform_device_del - remove a platform-level device
324 * @pdev: platform device we're removing
326 * Note that this function will also release all memory- and port-based
327 * resources owned by the device (@dev->resource). This function must
328 * _only_ be externally called in error cases. All other usage is a bug.
330 void platform_device_del(struct platform_device *pdev)
335 device_del(&pdev->dev);
337 for (i = 0; i < pdev->num_resources; i++) {
338 struct resource *r = &pdev->resource[i];
344 EXPORT_SYMBOL_GPL(platform_device_del);
347 * platform_device_register - add a platform-level device
348 * @pdev: platform device we're adding
350 int platform_device_register(struct platform_device *pdev)
352 device_initialize(&pdev->dev);
353 arch_setup_pdev_archdata(pdev);
354 return platform_device_add(pdev);
356 EXPORT_SYMBOL_GPL(platform_device_register);
359 * platform_device_unregister - unregister a platform-level device
360 * @pdev: platform device we're unregistering
362 * Unregistration is done in 2 steps. First we release all resources
363 * and remove it from the subsystem, then we drop reference count by
364 * calling platform_device_put().
366 void platform_device_unregister(struct platform_device *pdev)
368 platform_device_del(pdev);
369 platform_device_put(pdev);
371 EXPORT_SYMBOL_GPL(platform_device_unregister);
374 * platform_device_register_full - add a platform-level device with
375 * resources and platform-specific data
377 * @pdevinfo: data used to create device
379 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
381 struct platform_device *platform_device_register_full(
382 struct platform_device_info *pdevinfo)
385 struct platform_device *pdev;
387 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
391 pdev->dev.parent = pdevinfo->parent;
393 if (pdevinfo->dma_mask) {
395 * This memory isn't freed when the device is put,
396 * I don't have a nice idea for that though. Conceptually
397 * dma_mask in struct device should not be a pointer.
398 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
401 kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
402 if (!pdev->dev.dma_mask)
405 *pdev->dev.dma_mask = pdevinfo->dma_mask;
406 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
409 ret = platform_device_add_resources(pdev,
410 pdevinfo->res, pdevinfo->num_res);
414 ret = platform_device_add_data(pdev,
415 pdevinfo->data, pdevinfo->size_data);
419 ret = platform_device_add(pdev);
422 kfree(pdev->dev.dma_mask);
425 platform_device_put(pdev);
431 EXPORT_SYMBOL_GPL(platform_device_register_full);
433 static int platform_drv_probe(struct device *_dev)
435 struct platform_driver *drv = to_platform_driver(_dev->driver);
436 struct platform_device *dev = to_platform_device(_dev);
438 return drv->probe(dev);
441 static int platform_drv_probe_fail(struct device *_dev)
446 static int platform_drv_remove(struct device *_dev)
448 struct platform_driver *drv = to_platform_driver(_dev->driver);
449 struct platform_device *dev = to_platform_device(_dev);
451 return drv->remove(dev);
454 static void platform_drv_shutdown(struct device *_dev)
456 struct platform_driver *drv = to_platform_driver(_dev->driver);
457 struct platform_device *dev = to_platform_device(_dev);
463 * platform_driver_register - register a driver for platform-level devices
464 * @drv: platform driver structure
466 int platform_driver_register(struct platform_driver *drv)
468 drv->driver.bus = &platform_bus_type;
470 drv->driver.probe = platform_drv_probe;
472 drv->driver.remove = platform_drv_remove;
474 drv->driver.shutdown = platform_drv_shutdown;
476 return driver_register(&drv->driver);
478 EXPORT_SYMBOL_GPL(platform_driver_register);
481 * platform_driver_unregister - unregister a driver for platform-level devices
482 * @drv: platform driver structure
484 void platform_driver_unregister(struct platform_driver *drv)
486 driver_unregister(&drv->driver);
488 EXPORT_SYMBOL_GPL(platform_driver_unregister);
491 * platform_driver_probe - register driver for non-hotpluggable device
492 * @drv: platform driver structure
493 * @probe: the driver probe routine, probably from an __init section
495 * Use this instead of platform_driver_register() when you know the device
496 * is not hotpluggable and has already been registered, and you want to
497 * remove its run-once probe() infrastructure from memory after the driver
498 * has bound to the device.
500 * One typical use for this would be with drivers for controllers integrated
501 * into system-on-chip processors, where the controller devices have been
502 * configured as part of board setup.
504 * Returns zero if the driver registered and bound to a device, else returns
505 * a negative error code and with the driver not registered.
507 int __init_or_module platform_driver_probe(struct platform_driver *drv,
508 int (*probe)(struct platform_device *))
512 /* make sure driver won't have bind/unbind attributes */
513 drv->driver.suppress_bind_attrs = true;
515 /* temporary section violation during probe() */
517 retval = code = platform_driver_register(drv);
520 * Fixup that section violation, being paranoid about code scanning
521 * the list of drivers in order to probe new devices. Check to see
522 * if the probe was successful, and make sure any forced probes of
525 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
527 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
529 drv->driver.probe = platform_drv_probe_fail;
530 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
533 platform_driver_unregister(drv);
536 EXPORT_SYMBOL_GPL(platform_driver_probe);
539 * platform_create_bundle - register driver and create corresponding device
540 * @driver: platform driver structure
541 * @probe: the driver probe routine, probably from an __init section
542 * @res: set of resources that needs to be allocated for the device
543 * @n_res: number of resources
544 * @data: platform specific data for this platform device
545 * @size: size of platform specific data
547 * Use this in legacy-style modules that probe hardware directly and
548 * register a single platform device and corresponding platform driver.
550 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
552 struct platform_device * __init_or_module platform_create_bundle(
553 struct platform_driver *driver,
554 int (*probe)(struct platform_device *),
555 struct resource *res, unsigned int n_res,
556 const void *data, size_t size)
558 struct platform_device *pdev;
561 pdev = platform_device_alloc(driver->driver.name, -1);
567 error = platform_device_add_resources(pdev, res, n_res);
571 error = platform_device_add_data(pdev, data, size);
575 error = platform_device_add(pdev);
579 error = platform_driver_probe(driver, probe);
586 platform_device_del(pdev);
588 platform_device_put(pdev);
590 return ERR_PTR(error);
592 EXPORT_SYMBOL_GPL(platform_create_bundle);
594 /* modalias support enables more hands-off userspace setup:
595 * (a) environment variable lets new-style hotplug events work once system is
596 * fully running: "modprobe $MODALIAS"
597 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
598 * mishandled before system is fully running: "modprobe $(cat modalias)"
600 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
603 struct platform_device *pdev = to_platform_device(dev);
604 int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
606 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
609 static struct device_attribute platform_dev_attrs[] = {
614 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
616 struct platform_device *pdev = to_platform_device(dev);
619 /* Some devices have extra OF data and an OF-style MODALIAS */
620 rc = of_device_uevent(dev,env);
624 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
629 static const struct platform_device_id *platform_match_id(
630 const struct platform_device_id *id,
631 struct platform_device *pdev)
633 while (id->name[0]) {
634 if (strcmp(pdev->name, id->name) == 0) {
644 * platform_match - bind platform device to platform driver.
648 * Platform device IDs are assumed to be encoded like this:
649 * "<name><instance>", where <name> is a short description of the type of
650 * device, like "pci" or "floppy", and <instance> is the enumerated
651 * instance of the device, like '0' or '42'. Driver IDs are simply
652 * "<name>". So, extract the <name> from the platform_device structure,
653 * and compare it against the name of the driver. Return whether they match
656 static int platform_match(struct device *dev, struct device_driver *drv)
658 struct platform_device *pdev = to_platform_device(dev);
659 struct platform_driver *pdrv = to_platform_driver(drv);
661 /* Attempt an OF style match first */
662 if (of_driver_match_device(dev, drv))
665 /* Then try to match against the id table */
667 return platform_match_id(pdrv->id_table, pdev) != NULL;
669 /* fall-back to driver name match */
670 return (strcmp(pdev->name, drv->name) == 0);
673 #ifdef CONFIG_PM_SLEEP
675 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
677 struct platform_driver *pdrv = to_platform_driver(dev->driver);
678 struct platform_device *pdev = to_platform_device(dev);
681 if (dev->driver && pdrv->suspend)
682 ret = pdrv->suspend(pdev, mesg);
687 static int platform_legacy_resume(struct device *dev)
689 struct platform_driver *pdrv = to_platform_driver(dev->driver);
690 struct platform_device *pdev = to_platform_device(dev);
693 if (dev->driver && pdrv->resume)
694 ret = pdrv->resume(pdev);
699 int platform_pm_prepare(struct device *dev)
701 struct device_driver *drv = dev->driver;
704 if (drv && drv->pm && drv->pm->prepare)
705 ret = drv->pm->prepare(dev);
710 void platform_pm_complete(struct device *dev)
712 struct device_driver *drv = dev->driver;
714 if (drv && drv->pm && drv->pm->complete)
715 drv->pm->complete(dev);
718 #endif /* CONFIG_PM_SLEEP */
720 #ifdef CONFIG_SUSPEND
722 int platform_pm_suspend(struct device *dev)
724 struct device_driver *drv = dev->driver;
731 if (drv->pm->suspend)
732 ret = drv->pm->suspend(dev);
734 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
740 int platform_pm_suspend_noirq(struct device *dev)
742 struct device_driver *drv = dev->driver;
749 if (drv->pm->suspend_noirq)
750 ret = drv->pm->suspend_noirq(dev);
756 int platform_pm_resume(struct device *dev)
758 struct device_driver *drv = dev->driver;
766 ret = drv->pm->resume(dev);
768 ret = platform_legacy_resume(dev);
774 int platform_pm_resume_noirq(struct device *dev)
776 struct device_driver *drv = dev->driver;
783 if (drv->pm->resume_noirq)
784 ret = drv->pm->resume_noirq(dev);
790 #endif /* CONFIG_SUSPEND */
792 #ifdef CONFIG_HIBERNATE_CALLBACKS
794 int platform_pm_freeze(struct device *dev)
796 struct device_driver *drv = dev->driver;
804 ret = drv->pm->freeze(dev);
806 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
812 int platform_pm_freeze_noirq(struct device *dev)
814 struct device_driver *drv = dev->driver;
821 if (drv->pm->freeze_noirq)
822 ret = drv->pm->freeze_noirq(dev);
828 int platform_pm_thaw(struct device *dev)
830 struct device_driver *drv = dev->driver;
838 ret = drv->pm->thaw(dev);
840 ret = platform_legacy_resume(dev);
846 int platform_pm_thaw_noirq(struct device *dev)
848 struct device_driver *drv = dev->driver;
855 if (drv->pm->thaw_noirq)
856 ret = drv->pm->thaw_noirq(dev);
862 int platform_pm_poweroff(struct device *dev)
864 struct device_driver *drv = dev->driver;
871 if (drv->pm->poweroff)
872 ret = drv->pm->poweroff(dev);
874 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
880 int platform_pm_poweroff_noirq(struct device *dev)
882 struct device_driver *drv = dev->driver;
889 if (drv->pm->poweroff_noirq)
890 ret = drv->pm->poweroff_noirq(dev);
896 int platform_pm_restore(struct device *dev)
898 struct device_driver *drv = dev->driver;
905 if (drv->pm->restore)
906 ret = drv->pm->restore(dev);
908 ret = platform_legacy_resume(dev);
914 int platform_pm_restore_noirq(struct device *dev)
916 struct device_driver *drv = dev->driver;
923 if (drv->pm->restore_noirq)
924 ret = drv->pm->restore_noirq(dev);
930 #endif /* CONFIG_HIBERNATE_CALLBACKS */
932 static const struct dev_pm_ops platform_dev_pm_ops = {
933 .runtime_suspend = pm_generic_runtime_suspend,
934 .runtime_resume = pm_generic_runtime_resume,
935 .runtime_idle = pm_generic_runtime_idle,
936 USE_PLATFORM_PM_SLEEP_OPS
939 struct bus_type platform_bus_type = {
941 .dev_attrs = platform_dev_attrs,
942 .match = platform_match,
943 .uevent = platform_uevent,
944 .pm = &platform_dev_pm_ops,
946 EXPORT_SYMBOL_GPL(platform_bus_type);
948 int __init platform_bus_init(void)
952 early_platform_cleanup();
954 error = device_register(&platform_bus);
957 error = bus_register(&platform_bus_type);
959 device_unregister(&platform_bus);
963 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
964 u64 dma_get_required_mask(struct device *dev)
966 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
967 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
970 if (!high_totalram) {
971 /* convert to mask just covering totalram */
972 low_totalram = (1 << (fls(low_totalram) - 1));
973 low_totalram += low_totalram - 1;
976 high_totalram = (1 << (fls(high_totalram) - 1));
977 high_totalram += high_totalram - 1;
978 mask = (((u64)high_totalram) << 32) + 0xffffffff;
982 EXPORT_SYMBOL_GPL(dma_get_required_mask);
985 static __initdata LIST_HEAD(early_platform_driver_list);
986 static __initdata LIST_HEAD(early_platform_device_list);
989 * early_platform_driver_register - register early platform driver
990 * @epdrv: early_platform driver structure
991 * @buf: string passed from early_param()
993 * Helper function for early_platform_init() / early_platform_init_buffer()
995 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1001 /* Simply add the driver to the end of the global list.
1002 * Drivers will by default be put on the list in compiled-in order.
1004 if (!epdrv->list.next) {
1005 INIT_LIST_HEAD(&epdrv->list);
1006 list_add_tail(&epdrv->list, &early_platform_driver_list);
1009 /* If the user has specified device then make sure the driver
1010 * gets prioritized. The driver of the last device specified on
1011 * command line will be put first on the list.
1013 n = strlen(epdrv->pdrv->driver.name);
1014 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1015 list_move(&epdrv->list, &early_platform_driver_list);
1017 /* Allow passing parameters after device name */
1018 if (buf[n] == '\0' || buf[n] == ',')
1019 epdrv->requested_id = -1;
1021 epdrv->requested_id = simple_strtoul(&buf[n + 1],
1024 if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1025 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1028 n += strcspn(&buf[n + 1], ",") + 1;
1034 if (epdrv->bufsize) {
1035 memcpy(epdrv->buffer, &buf[n],
1036 min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1037 epdrv->buffer[epdrv->bufsize - 1] = '\0';
1045 * early_platform_add_devices - adds a number of early platform devices
1046 * @devs: array of early platform devices to add
1047 * @num: number of early platform devices in array
1049 * Used by early architecture code to register early platform devices and
1050 * their platform data.
1052 void __init early_platform_add_devices(struct platform_device **devs, int num)
1057 /* simply add the devices to list */
1058 for (i = 0; i < num; i++) {
1059 dev = &devs[i]->dev;
1061 if (!dev->devres_head.next) {
1062 INIT_LIST_HEAD(&dev->devres_head);
1063 list_add_tail(&dev->devres_head,
1064 &early_platform_device_list);
1070 * early_platform_driver_register_all - register early platform drivers
1071 * @class_str: string to identify early platform driver class
1073 * Used by architecture code to register all early platform drivers
1074 * for a certain class. If omitted then only early platform drivers
1075 * with matching kernel command line class parameters will be registered.
1077 void __init early_platform_driver_register_all(char *class_str)
1079 /* The "class_str" parameter may or may not be present on the kernel
1080 * command line. If it is present then there may be more than one
1081 * matching parameter.
1083 * Since we register our early platform drivers using early_param()
1084 * we need to make sure that they also get registered in the case
1085 * when the parameter is missing from the kernel command line.
1087 * We use parse_early_options() to make sure the early_param() gets
1088 * called at least once. The early_param() may be called more than
1089 * once since the name of the preferred device may be specified on
1090 * the kernel command line. early_platform_driver_register() handles
1093 parse_early_options(class_str);
1097 * early_platform_match - find early platform device matching driver
1098 * @epdrv: early platform driver structure
1099 * @id: id to match against
1101 static __init struct platform_device *
1102 early_platform_match(struct early_platform_driver *epdrv, int id)
1104 struct platform_device *pd;
1106 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1107 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1115 * early_platform_left - check if early platform driver has matching devices
1116 * @epdrv: early platform driver structure
1117 * @id: return true if id or above exists
1119 static __init int early_platform_left(struct early_platform_driver *epdrv,
1122 struct platform_device *pd;
1124 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1125 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1133 * early_platform_driver_probe_id - probe drivers matching class_str and id
1134 * @class_str: string to identify early platform driver class
1135 * @id: id to match against
1136 * @nr_probe: number of platform devices to successfully probe before exiting
1138 static int __init early_platform_driver_probe_id(char *class_str,
1142 struct early_platform_driver *epdrv;
1143 struct platform_device *match;
1148 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1149 /* only use drivers matching our class_str */
1150 if (strcmp(class_str, epdrv->class_str))
1154 match_id = epdrv->requested_id;
1159 left += early_platform_left(epdrv, id);
1161 /* skip requested id */
1162 switch (epdrv->requested_id) {
1163 case EARLY_PLATFORM_ID_ERROR:
1164 case EARLY_PLATFORM_ID_UNSET:
1167 if (epdrv->requested_id == id)
1168 match_id = EARLY_PLATFORM_ID_UNSET;
1173 case EARLY_PLATFORM_ID_ERROR:
1174 pr_warning("%s: unable to parse %s parameter\n",
1175 class_str, epdrv->pdrv->driver.name);
1177 case EARLY_PLATFORM_ID_UNSET:
1181 match = early_platform_match(epdrv, match_id);
1186 * Set up a sensible init_name to enable
1187 * dev_name() and others to be used before the
1188 * rest of the driver core is initialized.
1190 if (!match->dev.init_name && slab_is_available()) {
1191 if (match->id != -1)
1192 match->dev.init_name =
1193 kasprintf(GFP_KERNEL, "%s.%d",
1197 match->dev.init_name =
1198 kasprintf(GFP_KERNEL, "%s",
1201 if (!match->dev.init_name)
1205 if (epdrv->pdrv->probe(match))
1206 pr_warning("%s: unable to probe %s early.\n",
1207 class_str, match->name);
1223 * early_platform_driver_probe - probe a class of registered drivers
1224 * @class_str: string to identify early platform driver class
1225 * @nr_probe: number of platform devices to successfully probe before exiting
1226 * @user_only: only probe user specified early platform devices
1228 * Used by architecture code to probe registered early platform drivers
1229 * within a certain class. For probe to happen a registered early platform
1230 * device matching a registered early platform driver is needed.
1232 int __init early_platform_driver_probe(char *class_str,
1239 for (i = -2; n < nr_probe; i++) {
1240 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1255 * early_platform_cleanup - clean up early platform code
1257 void __init early_platform_cleanup(void)
1259 struct platform_device *pd, *pd2;
1261 /* clean up the devres list used to chain devices */
1262 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1264 list_del(&pd->dev.devres_head);
1265 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));