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/platform_device.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/bootmem.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
23 #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \
26 struct device platform_bus = {
27 .init_name = "platform",
29 EXPORT_SYMBOL_GPL(platform_bus);
32 * platform_get_resource - get a resource for a device
33 * @dev: platform device
34 * @type: resource type
35 * @num: resource index
37 struct resource *platform_get_resource(struct platform_device *dev,
38 unsigned int type, unsigned int num)
42 for (i = 0; i < dev->num_resources; i++) {
43 struct resource *r = &dev->resource[i];
45 if (type == resource_type(r) && num-- == 0)
50 EXPORT_SYMBOL_GPL(platform_get_resource);
53 * platform_get_irq - get an IRQ for a device
54 * @dev: platform device
55 * @num: IRQ number index
57 int platform_get_irq(struct platform_device *dev, unsigned int num)
59 struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
61 return r ? r->start : -ENXIO;
63 EXPORT_SYMBOL_GPL(platform_get_irq);
66 * platform_get_resource_byname - get a resource for a device by name
67 * @dev: platform device
68 * @type: resource type
69 * @name: resource name
71 struct resource *platform_get_resource_byname(struct platform_device *dev,
77 for (i = 0; i < dev->num_resources; i++) {
78 struct resource *r = &dev->resource[i];
80 if (type == resource_type(r) && !strcmp(r->name, name))
85 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
88 * platform_get_irq - get an IRQ for a device
89 * @dev: platform device
92 int platform_get_irq_byname(struct platform_device *dev, const char *name)
94 struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
97 return r ? r->start : -ENXIO;
99 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
102 * platform_add_devices - add a numbers of platform devices
103 * @devs: array of platform devices to add
104 * @num: number of platform devices in array
106 int platform_add_devices(struct platform_device **devs, int num)
110 for (i = 0; i < num; i++) {
111 ret = platform_device_register(devs[i]);
114 platform_device_unregister(devs[i]);
121 EXPORT_SYMBOL_GPL(platform_add_devices);
123 struct platform_object {
124 struct platform_device pdev;
129 * platform_device_put
130 * @pdev: platform device to free
132 * Free all memory associated with a platform device. This function must
133 * _only_ be externally called in error cases. All other usage is a bug.
135 void platform_device_put(struct platform_device *pdev)
138 put_device(&pdev->dev);
140 EXPORT_SYMBOL_GPL(platform_device_put);
142 static void platform_device_release(struct device *dev)
144 struct platform_object *pa = container_of(dev, struct platform_object,
147 kfree(pa->pdev.dev.platform_data);
148 kfree(pa->pdev.resource);
153 * platform_device_alloc
154 * @name: base name of the device we're adding
157 * Create a platform device object which can have other objects attached
158 * to it, and which will have attached objects freed when it is released.
160 struct platform_device *platform_device_alloc(const char *name, int id)
162 struct platform_object *pa;
164 pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
166 strcpy(pa->name, name);
167 pa->pdev.name = pa->name;
169 device_initialize(&pa->pdev.dev);
170 pa->pdev.dev.release = platform_device_release;
173 return pa ? &pa->pdev : NULL;
175 EXPORT_SYMBOL_GPL(platform_device_alloc);
178 * platform_device_add_resources
179 * @pdev: platform device allocated by platform_device_alloc to add resources to
180 * @res: set of resources that needs to be allocated for the device
181 * @num: number of resources
183 * Add a copy of the resources to the platform device. The memory
184 * associated with the resources will be freed when the platform device is
187 int platform_device_add_resources(struct platform_device *pdev,
188 struct resource *res, unsigned int num)
192 r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL);
194 memcpy(r, res, sizeof(struct resource) * num);
196 pdev->num_resources = num;
198 return r ? 0 : -ENOMEM;
200 EXPORT_SYMBOL_GPL(platform_device_add_resources);
203 * platform_device_add_data
204 * @pdev: platform device allocated by platform_device_alloc to add resources to
205 * @data: platform specific data for this platform device
206 * @size: size of platform specific data
208 * Add a copy of platform specific data to the platform device's
209 * platform_data pointer. The memory associated with the platform data
210 * will be freed when the platform device is released.
212 int platform_device_add_data(struct platform_device *pdev, const void *data,
217 d = kmalloc(size, GFP_KERNEL);
219 memcpy(d, data, size);
220 pdev->dev.platform_data = d;
222 return d ? 0 : -ENOMEM;
224 EXPORT_SYMBOL_GPL(platform_device_add_data);
227 * platform_device_add - add a platform device to device hierarchy
228 * @pdev: platform device we're adding
230 * This is part 2 of platform_device_register(), though may be called
231 * separately _iff_ pdev was allocated by platform_device_alloc().
233 int platform_device_add(struct platform_device *pdev)
240 if (!pdev->dev.parent)
241 pdev->dev.parent = &platform_bus;
243 pdev->dev.bus = &platform_bus_type;
246 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
248 dev_set_name(&pdev->dev, "%s", pdev->name);
250 for (i = 0; i < pdev->num_resources; i++) {
251 struct resource *p, *r = &pdev->resource[i];
254 r->name = dev_name(&pdev->dev);
258 if (resource_type(r) == IORESOURCE_MEM)
260 else if (resource_type(r) == IORESOURCE_IO)
261 p = &ioport_resource;
264 if (p && insert_resource(p, r)) {
266 "%s: failed to claim resource %d\n",
267 dev_name(&pdev->dev), i);
273 pr_debug("Registering platform device '%s'. Parent at %s\n",
274 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
276 ret = device_add(&pdev->dev);
282 struct resource *r = &pdev->resource[i];
283 unsigned long type = resource_type(r);
285 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
291 EXPORT_SYMBOL_GPL(platform_device_add);
294 * platform_device_del - remove a platform-level device
295 * @pdev: platform device we're removing
297 * Note that this function will also release all memory- and port-based
298 * resources owned by the device (@dev->resource). This function must
299 * _only_ be externally called in error cases. All other usage is a bug.
301 void platform_device_del(struct platform_device *pdev)
306 device_del(&pdev->dev);
308 for (i = 0; i < pdev->num_resources; i++) {
309 struct resource *r = &pdev->resource[i];
310 unsigned long type = resource_type(r);
312 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
317 EXPORT_SYMBOL_GPL(platform_device_del);
320 * platform_device_register - add a platform-level device
321 * @pdev: platform device we're adding
323 int platform_device_register(struct platform_device *pdev)
325 device_initialize(&pdev->dev);
326 return platform_device_add(pdev);
328 EXPORT_SYMBOL_GPL(platform_device_register);
331 * platform_device_unregister - unregister a platform-level device
332 * @pdev: platform device we're unregistering
334 * Unregistration is done in 2 steps. First we release all resources
335 * and remove it from the subsystem, then we drop reference count by
336 * calling platform_device_put().
338 void platform_device_unregister(struct platform_device *pdev)
340 platform_device_del(pdev);
341 platform_device_put(pdev);
343 EXPORT_SYMBOL_GPL(platform_device_unregister);
346 * platform_device_register_simple
347 * @name: base name of the device we're adding
349 * @res: set of resources that needs to be allocated for the device
350 * @num: number of resources
352 * This function creates a simple platform device that requires minimal
353 * resource and memory management. Canned release function freeing memory
354 * allocated for the device allows drivers using such devices to be
355 * unloaded without waiting for the last reference to the device to be
358 * This interface is primarily intended for use with legacy drivers which
359 * probe hardware directly. Because such drivers create sysfs device nodes
360 * themselves, rather than letting system infrastructure handle such device
361 * enumeration tasks, they don't fully conform to the Linux driver model.
362 * In particular, when such drivers are built as modules, they can't be
365 struct platform_device *platform_device_register_simple(const char *name,
367 struct resource *res,
370 struct platform_device *pdev;
373 pdev = platform_device_alloc(name, id);
380 retval = platform_device_add_resources(pdev, res, num);
385 retval = platform_device_add(pdev);
392 platform_device_put(pdev);
393 return ERR_PTR(retval);
395 EXPORT_SYMBOL_GPL(platform_device_register_simple);
398 * platform_device_register_data
399 * @parent: parent device for the device we're adding
400 * @name: base name of the device we're adding
402 * @data: platform specific data for this platform device
403 * @size: size of platform specific data
405 * This function creates a simple platform device that requires minimal
406 * resource and memory management. Canned release function freeing memory
407 * allocated for the device allows drivers using such devices to be
408 * unloaded without waiting for the last reference to the device to be
411 struct platform_device *platform_device_register_data(
412 struct device *parent,
413 const char *name, int id,
414 const void *data, size_t size)
416 struct platform_device *pdev;
419 pdev = platform_device_alloc(name, id);
425 pdev->dev.parent = parent;
428 retval = platform_device_add_data(pdev, data, size);
433 retval = platform_device_add(pdev);
440 platform_device_put(pdev);
441 return ERR_PTR(retval);
444 static int platform_drv_probe(struct device *_dev)
446 struct platform_driver *drv = to_platform_driver(_dev->driver);
447 struct platform_device *dev = to_platform_device(_dev);
449 return drv->probe(dev);
452 static int platform_drv_probe_fail(struct device *_dev)
457 static int platform_drv_remove(struct device *_dev)
459 struct platform_driver *drv = to_platform_driver(_dev->driver);
460 struct platform_device *dev = to_platform_device(_dev);
462 return drv->remove(dev);
465 static void platform_drv_shutdown(struct device *_dev)
467 struct platform_driver *drv = to_platform_driver(_dev->driver);
468 struct platform_device *dev = to_platform_device(_dev);
474 * platform_driver_register
475 * @drv: platform driver structure
477 int platform_driver_register(struct platform_driver *drv)
479 drv->driver.bus = &platform_bus_type;
481 drv->driver.probe = platform_drv_probe;
483 drv->driver.remove = platform_drv_remove;
485 drv->driver.shutdown = platform_drv_shutdown;
486 if (drv->suspend || drv->resume)
487 pr_warning("Platform driver '%s' needs updating - please use "
488 "dev_pm_ops\n", drv->driver.name);
490 return driver_register(&drv->driver);
492 EXPORT_SYMBOL_GPL(platform_driver_register);
495 * platform_driver_unregister
496 * @drv: platform driver structure
498 void platform_driver_unregister(struct platform_driver *drv)
500 driver_unregister(&drv->driver);
502 EXPORT_SYMBOL_GPL(platform_driver_unregister);
505 * platform_driver_probe - register driver for non-hotpluggable device
506 * @drv: platform driver structure
507 * @probe: the driver probe routine, probably from an __init section
509 * Use this instead of platform_driver_register() when you know the device
510 * is not hotpluggable and has already been registered, and you want to
511 * remove its run-once probe() infrastructure from memory after the driver
512 * has bound to the device.
514 * One typical use for this would be with drivers for controllers integrated
515 * into system-on-chip processors, where the controller devices have been
516 * configured as part of board setup.
518 * Returns zero if the driver registered and bound to a device, else returns
519 * a negative error code and with the driver not registered.
521 int __init_or_module platform_driver_probe(struct platform_driver *drv,
522 int (*probe)(struct platform_device *))
526 /* temporary section violation during probe() */
528 retval = code = platform_driver_register(drv);
530 /* Fixup that section violation, being paranoid about code scanning
531 * the list of drivers in order to probe new devices. Check to see
532 * if the probe was successful, and make sure any forced probes of
535 spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
537 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
539 drv->driver.probe = platform_drv_probe_fail;
540 spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
543 platform_driver_unregister(drv);
546 EXPORT_SYMBOL_GPL(platform_driver_probe);
548 /* modalias support enables more hands-off userspace setup:
549 * (a) environment variable lets new-style hotplug events work once system is
550 * fully running: "modprobe $MODALIAS"
551 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
552 * mishandled before system is fully running: "modprobe $(cat modalias)"
554 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
557 struct platform_device *pdev = to_platform_device(dev);
558 int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
560 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
563 static struct device_attribute platform_dev_attrs[] = {
568 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
570 struct platform_device *pdev = to_platform_device(dev);
572 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
573 (pdev->id_entry) ? pdev->id_entry->name : pdev->name);
577 static const struct platform_device_id *platform_match_id(
578 struct platform_device_id *id,
579 struct platform_device *pdev)
581 while (id->name[0]) {
582 if (strcmp(pdev->name, id->name) == 0) {
592 * platform_match - bind platform device to platform driver.
596 * Platform device IDs are assumed to be encoded like this:
597 * "<name><instance>", where <name> is a short description of the type of
598 * device, like "pci" or "floppy", and <instance> is the enumerated
599 * instance of the device, like '0' or '42'. Driver IDs are simply
600 * "<name>". So, extract the <name> from the platform_device structure,
601 * and compare it against the name of the driver. Return whether they match
604 static int platform_match(struct device *dev, struct device_driver *drv)
606 struct platform_device *pdev = to_platform_device(dev);
607 struct platform_driver *pdrv = to_platform_driver(drv);
609 /* match against the id table first */
611 return platform_match_id(pdrv->id_table, pdev) != NULL;
613 /* fall-back to driver name match */
614 return (strcmp(pdev->name, drv->name) == 0);
617 #ifdef CONFIG_PM_SLEEP
619 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
621 struct platform_driver *pdrv = to_platform_driver(dev->driver);
622 struct platform_device *pdev = to_platform_device(dev);
625 if (dev->driver && pdrv->suspend)
626 ret = pdrv->suspend(pdev, mesg);
631 static int platform_legacy_suspend_late(struct device *dev, pm_message_t mesg)
633 struct platform_driver *pdrv = to_platform_driver(dev->driver);
634 struct platform_device *pdev = to_platform_device(dev);
637 if (dev->driver && pdrv->suspend_late)
638 ret = pdrv->suspend_late(pdev, mesg);
643 static int platform_legacy_resume_early(struct device *dev)
645 struct platform_driver *pdrv = to_platform_driver(dev->driver);
646 struct platform_device *pdev = to_platform_device(dev);
649 if (dev->driver && pdrv->resume_early)
650 ret = pdrv->resume_early(pdev);
655 static int platform_legacy_resume(struct device *dev)
657 struct platform_driver *pdrv = to_platform_driver(dev->driver);
658 struct platform_device *pdev = to_platform_device(dev);
661 if (dev->driver && pdrv->resume)
662 ret = pdrv->resume(pdev);
667 static int platform_pm_prepare(struct device *dev)
669 struct device_driver *drv = dev->driver;
672 if (drv && drv->pm && drv->pm->prepare)
673 ret = drv->pm->prepare(dev);
678 static void platform_pm_complete(struct device *dev)
680 struct device_driver *drv = dev->driver;
682 if (drv && drv->pm && drv->pm->complete)
683 drv->pm->complete(dev);
686 #ifdef CONFIG_SUSPEND
688 static int platform_pm_suspend(struct device *dev)
690 struct device_driver *drv = dev->driver;
697 if (drv->pm->suspend)
698 ret = drv->pm->suspend(dev);
700 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
706 static int platform_pm_suspend_noirq(struct device *dev)
708 struct device_driver *drv = dev->driver;
715 if (drv->pm->suspend_noirq)
716 ret = drv->pm->suspend_noirq(dev);
718 ret = platform_legacy_suspend_late(dev, PMSG_SUSPEND);
724 static int platform_pm_resume(struct device *dev)
726 struct device_driver *drv = dev->driver;
734 ret = drv->pm->resume(dev);
736 ret = platform_legacy_resume(dev);
742 static int platform_pm_resume_noirq(struct device *dev)
744 struct device_driver *drv = dev->driver;
751 if (drv->pm->resume_noirq)
752 ret = drv->pm->resume_noirq(dev);
754 ret = platform_legacy_resume_early(dev);
760 #else /* !CONFIG_SUSPEND */
762 #define platform_pm_suspend NULL
763 #define platform_pm_resume NULL
764 #define platform_pm_suspend_noirq NULL
765 #define platform_pm_resume_noirq NULL
767 #endif /* !CONFIG_SUSPEND */
769 #ifdef CONFIG_HIBERNATION
771 static int platform_pm_freeze(struct device *dev)
773 struct device_driver *drv = dev->driver;
781 ret = drv->pm->freeze(dev);
783 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
789 static int platform_pm_freeze_noirq(struct device *dev)
791 struct device_driver *drv = dev->driver;
798 if (drv->pm->freeze_noirq)
799 ret = drv->pm->freeze_noirq(dev);
801 ret = platform_legacy_suspend_late(dev, PMSG_FREEZE);
807 static int platform_pm_thaw(struct device *dev)
809 struct device_driver *drv = dev->driver;
817 ret = drv->pm->thaw(dev);
819 ret = platform_legacy_resume(dev);
825 static int platform_pm_thaw_noirq(struct device *dev)
827 struct device_driver *drv = dev->driver;
834 if (drv->pm->thaw_noirq)
835 ret = drv->pm->thaw_noirq(dev);
837 ret = platform_legacy_resume_early(dev);
843 static int platform_pm_poweroff(struct device *dev)
845 struct device_driver *drv = dev->driver;
852 if (drv->pm->poweroff)
853 ret = drv->pm->poweroff(dev);
855 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
861 static int platform_pm_poweroff_noirq(struct device *dev)
863 struct device_driver *drv = dev->driver;
870 if (drv->pm->poweroff_noirq)
871 ret = drv->pm->poweroff_noirq(dev);
873 ret = platform_legacy_suspend_late(dev, PMSG_HIBERNATE);
879 static int platform_pm_restore(struct device *dev)
881 struct device_driver *drv = dev->driver;
888 if (drv->pm->restore)
889 ret = drv->pm->restore(dev);
891 ret = platform_legacy_resume(dev);
897 static int platform_pm_restore_noirq(struct device *dev)
899 struct device_driver *drv = dev->driver;
906 if (drv->pm->restore_noirq)
907 ret = drv->pm->restore_noirq(dev);
909 ret = platform_legacy_resume_early(dev);
915 #else /* !CONFIG_HIBERNATION */
917 #define platform_pm_freeze NULL
918 #define platform_pm_thaw NULL
919 #define platform_pm_poweroff NULL
920 #define platform_pm_restore NULL
921 #define platform_pm_freeze_noirq NULL
922 #define platform_pm_thaw_noirq NULL
923 #define platform_pm_poweroff_noirq NULL
924 #define platform_pm_restore_noirq NULL
926 #endif /* !CONFIG_HIBERNATION */
928 static struct dev_pm_ops platform_dev_pm_ops = {
929 .prepare = platform_pm_prepare,
930 .complete = platform_pm_complete,
931 .suspend = platform_pm_suspend,
932 .resume = platform_pm_resume,
933 .freeze = platform_pm_freeze,
934 .thaw = platform_pm_thaw,
935 .poweroff = platform_pm_poweroff,
936 .restore = platform_pm_restore,
937 .suspend_noirq = platform_pm_suspend_noirq,
938 .resume_noirq = platform_pm_resume_noirq,
939 .freeze_noirq = platform_pm_freeze_noirq,
940 .thaw_noirq = platform_pm_thaw_noirq,
941 .poweroff_noirq = platform_pm_poweroff_noirq,
942 .restore_noirq = platform_pm_restore_noirq,
945 #define PLATFORM_PM_OPS_PTR (&platform_dev_pm_ops)
947 #else /* !CONFIG_PM_SLEEP */
949 #define PLATFORM_PM_OPS_PTR NULL
951 #endif /* !CONFIG_PM_SLEEP */
953 struct bus_type platform_bus_type = {
955 .dev_attrs = platform_dev_attrs,
956 .match = platform_match,
957 .uevent = platform_uevent,
958 .pm = PLATFORM_PM_OPS_PTR,
960 EXPORT_SYMBOL_GPL(platform_bus_type);
962 int __init platform_bus_init(void)
966 early_platform_cleanup();
968 error = device_register(&platform_bus);
971 error = bus_register(&platform_bus_type);
973 device_unregister(&platform_bus);
977 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
978 u64 dma_get_required_mask(struct device *dev)
980 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
981 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
984 if (!high_totalram) {
985 /* convert to mask just covering totalram */
986 low_totalram = (1 << (fls(low_totalram) - 1));
987 low_totalram += low_totalram - 1;
990 high_totalram = (1 << (fls(high_totalram) - 1));
991 high_totalram += high_totalram - 1;
992 mask = (((u64)high_totalram) << 32) + 0xffffffff;
996 EXPORT_SYMBOL_GPL(dma_get_required_mask);
999 static __initdata LIST_HEAD(early_platform_driver_list);
1000 static __initdata LIST_HEAD(early_platform_device_list);
1003 * early_platform_driver_register
1004 * @epdrv: early_platform driver structure
1005 * @buf: string passed from early_param()
1007 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1010 unsigned long index;
1013 /* Simply add the driver to the end of the global list.
1014 * Drivers will by default be put on the list in compiled-in order.
1016 if (!epdrv->list.next) {
1017 INIT_LIST_HEAD(&epdrv->list);
1018 list_add_tail(&epdrv->list, &early_platform_driver_list);
1021 /* If the user has specified device then make sure the driver
1022 * gets prioritized. The driver of the last device specified on
1023 * command line will be put first on the list.
1025 n = strlen(epdrv->pdrv->driver.name);
1026 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1027 list_move(&epdrv->list, &early_platform_driver_list);
1029 if (!strcmp(buf, epdrv->pdrv->driver.name))
1030 epdrv->requested_id = -1;
1031 else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
1033 epdrv->requested_id = index;
1035 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1042 * early_platform_add_devices - add a numbers of early platform devices
1043 * @devs: array of early platform devices to add
1044 * @num: number of early platform devices in array
1046 void __init early_platform_add_devices(struct platform_device **devs, int num)
1051 /* simply add the devices to list */
1052 for (i = 0; i < num; i++) {
1053 dev = &devs[i]->dev;
1055 if (!dev->devres_head.next) {
1056 INIT_LIST_HEAD(&dev->devres_head);
1057 list_add_tail(&dev->devres_head,
1058 &early_platform_device_list);
1064 * early_platform_driver_register_all
1065 * @class_str: string to identify early platform driver class
1067 void __init early_platform_driver_register_all(char *class_str)
1069 /* The "class_str" parameter may or may not be present on the kernel
1070 * command line. If it is present then there may be more than one
1071 * matching parameter.
1073 * Since we register our early platform drivers using early_param()
1074 * we need to make sure that they also get registered in the case
1075 * when the parameter is missing from the kernel command line.
1077 * We use parse_early_options() to make sure the early_param() gets
1078 * called at least once. The early_param() may be called more than
1079 * once since the name of the preferred device may be specified on
1080 * the kernel command line. early_platform_driver_register() handles
1083 parse_early_options(class_str);
1087 * early_platform_match
1088 * @epdrv: early platform driver structure
1089 * @id: id to match against
1091 static __init struct platform_device *
1092 early_platform_match(struct early_platform_driver *epdrv, int id)
1094 struct platform_device *pd;
1096 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1097 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1105 * early_platform_left
1106 * @epdrv: early platform driver structure
1107 * @id: return true if id or above exists
1109 static __init int early_platform_left(struct early_platform_driver *epdrv,
1112 struct platform_device *pd;
1114 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1115 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1123 * early_platform_driver_probe_id
1124 * @class_str: string to identify early platform driver class
1125 * @id: id to match against
1126 * @nr_probe: number of platform devices to successfully probe before exiting
1128 static int __init early_platform_driver_probe_id(char *class_str,
1132 struct early_platform_driver *epdrv;
1133 struct platform_device *match;
1138 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1139 /* only use drivers matching our class_str */
1140 if (strcmp(class_str, epdrv->class_str))
1144 match_id = epdrv->requested_id;
1149 left += early_platform_left(epdrv, id);
1151 /* skip requested id */
1152 switch (epdrv->requested_id) {
1153 case EARLY_PLATFORM_ID_ERROR:
1154 case EARLY_PLATFORM_ID_UNSET:
1157 if (epdrv->requested_id == id)
1158 match_id = EARLY_PLATFORM_ID_UNSET;
1163 case EARLY_PLATFORM_ID_ERROR:
1164 pr_warning("%s: unable to parse %s parameter\n",
1165 class_str, epdrv->pdrv->driver.name);
1167 case EARLY_PLATFORM_ID_UNSET:
1171 match = early_platform_match(epdrv, match_id);
1175 if (epdrv->pdrv->probe(match))
1176 pr_warning("%s: unable to probe %s early.\n",
1177 class_str, match->name);
1193 * early_platform_driver_probe
1194 * @class_str: string to identify early platform driver class
1195 * @nr_probe: number of platform devices to successfully probe before exiting
1196 * @user_only: only probe user specified early platform devices
1198 int __init early_platform_driver_probe(char *class_str,
1205 for (i = -2; n < nr_probe; i++) {
1206 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1221 * early_platform_cleanup - clean up early platform code
1223 void __init early_platform_cleanup(void)
1225 struct platform_device *pd, *pd2;
1227 /* clean up the devres list used to chain devices */
1228 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1230 list_del(&pd->dev.devres_head);
1231 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));