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,
72 unsigned int type, char *name)
76 for (i = 0; i < dev->num_resources; i++) {
77 struct resource *r = &dev->resource[i];
79 if (type == resource_type(r) && !strcmp(r->name, name))
84 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
87 * platform_get_irq - get an IRQ for a device
88 * @dev: platform device
91 int platform_get_irq_byname(struct platform_device *dev, char *name)
93 struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
96 return r ? r->start : -ENXIO;
98 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
101 * platform_add_devices - add a numbers of platform devices
102 * @devs: array of platform devices to add
103 * @num: number of platform devices in array
105 int platform_add_devices(struct platform_device **devs, int num)
109 for (i = 0; i < num; i++) {
110 ret = platform_device_register(devs[i]);
113 platform_device_unregister(devs[i]);
120 EXPORT_SYMBOL_GPL(platform_add_devices);
122 struct platform_object {
123 struct platform_device pdev;
128 * platform_device_put
129 * @pdev: platform device to free
131 * Free all memory associated with a platform device. This function must
132 * _only_ be externally called in error cases. All other usage is a bug.
134 void platform_device_put(struct platform_device *pdev)
137 put_device(&pdev->dev);
139 EXPORT_SYMBOL_GPL(platform_device_put);
141 static void platform_device_release(struct device *dev)
143 struct platform_object *pa = container_of(dev, struct platform_object,
146 kfree(pa->pdev.dev.platform_data);
147 kfree(pa->pdev.resource);
152 * platform_device_alloc
153 * @name: base name of the device we're adding
156 * Create a platform device object which can have other objects attached
157 * to it, and which will have attached objects freed when it is released.
159 struct platform_device *platform_device_alloc(const char *name, int id)
161 struct platform_object *pa;
163 pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
165 strcpy(pa->name, name);
166 pa->pdev.name = pa->name;
168 device_initialize(&pa->pdev.dev);
169 pa->pdev.dev.release = platform_device_release;
172 return pa ? &pa->pdev : NULL;
174 EXPORT_SYMBOL_GPL(platform_device_alloc);
177 * platform_device_add_resources
178 * @pdev: platform device allocated by platform_device_alloc to add resources to
179 * @res: set of resources that needs to be allocated for the device
180 * @num: number of resources
182 * Add a copy of the resources to the platform device. The memory
183 * associated with the resources will be freed when the platform device is
186 int platform_device_add_resources(struct platform_device *pdev,
187 struct resource *res, unsigned int num)
191 r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL);
193 memcpy(r, res, sizeof(struct resource) * num);
195 pdev->num_resources = num;
197 return r ? 0 : -ENOMEM;
199 EXPORT_SYMBOL_GPL(platform_device_add_resources);
202 * platform_device_add_data
203 * @pdev: platform device allocated by platform_device_alloc to add resources to
204 * @data: platform specific data for this platform device
205 * @size: size of platform specific data
207 * Add a copy of platform specific data to the platform device's
208 * platform_data pointer. The memory associated with the platform data
209 * will be freed when the platform device is released.
211 int platform_device_add_data(struct platform_device *pdev, const void *data,
216 d = kmalloc(size, GFP_KERNEL);
218 memcpy(d, data, size);
219 pdev->dev.platform_data = d;
221 return d ? 0 : -ENOMEM;
223 EXPORT_SYMBOL_GPL(platform_device_add_data);
226 * platform_device_add - add a platform device to device hierarchy
227 * @pdev: platform device we're adding
229 * This is part 2 of platform_device_register(), though may be called
230 * separately _iff_ pdev was allocated by platform_device_alloc().
232 int platform_device_add(struct platform_device *pdev)
239 if (!pdev->dev.parent)
240 pdev->dev.parent = &platform_bus;
242 pdev->dev.bus = &platform_bus_type;
245 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
247 dev_set_name(&pdev->dev, pdev->name);
249 for (i = 0; i < pdev->num_resources; i++) {
250 struct resource *p, *r = &pdev->resource[i];
253 r->name = dev_name(&pdev->dev);
257 if (resource_type(r) == IORESOURCE_MEM)
259 else if (resource_type(r) == IORESOURCE_IO)
260 p = &ioport_resource;
263 if (p && insert_resource(p, r)) {
265 "%s: failed to claim resource %d\n",
266 dev_name(&pdev->dev), i);
272 pr_debug("Registering platform device '%s'. Parent at %s\n",
273 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
275 ret = device_add(&pdev->dev);
281 struct resource *r = &pdev->resource[i];
282 unsigned long type = resource_type(r);
284 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
290 EXPORT_SYMBOL_GPL(platform_device_add);
293 * platform_device_del - remove a platform-level device
294 * @pdev: platform device we're removing
296 * Note that this function will also release all memory- and port-based
297 * resources owned by the device (@dev->resource). This function must
298 * _only_ be externally called in error cases. All other usage is a bug.
300 void platform_device_del(struct platform_device *pdev)
305 device_del(&pdev->dev);
307 for (i = 0; i < pdev->num_resources; i++) {
308 struct resource *r = &pdev->resource[i];
309 unsigned long type = resource_type(r);
311 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
316 EXPORT_SYMBOL_GPL(platform_device_del);
319 * platform_device_register - add a platform-level device
320 * @pdev: platform device we're adding
322 int platform_device_register(struct platform_device *pdev)
324 device_initialize(&pdev->dev);
325 return platform_device_add(pdev);
327 EXPORT_SYMBOL_GPL(platform_device_register);
330 * platform_device_unregister - unregister a platform-level device
331 * @pdev: platform device we're unregistering
333 * Unregistration is done in 2 steps. First we release all resources
334 * and remove it from the subsystem, then we drop reference count by
335 * calling platform_device_put().
337 void platform_device_unregister(struct platform_device *pdev)
339 platform_device_del(pdev);
340 platform_device_put(pdev);
342 EXPORT_SYMBOL_GPL(platform_device_unregister);
345 * platform_device_register_simple
346 * @name: base name of the device we're adding
348 * @res: set of resources that needs to be allocated for the device
349 * @num: number of resources
351 * This function creates a simple platform device that requires minimal
352 * resource and memory management. Canned release function freeing memory
353 * allocated for the device allows drivers using such devices to be
354 * unloaded without waiting for the last reference to the device to be
357 * This interface is primarily intended for use with legacy drivers which
358 * probe hardware directly. Because such drivers create sysfs device nodes
359 * themselves, rather than letting system infrastructure handle such device
360 * enumeration tasks, they don't fully conform to the Linux driver model.
361 * In particular, when such drivers are built as modules, they can't be
364 struct platform_device *platform_device_register_simple(const char *name,
366 struct resource *res,
369 struct platform_device *pdev;
372 pdev = platform_device_alloc(name, id);
379 retval = platform_device_add_resources(pdev, res, num);
384 retval = platform_device_add(pdev);
391 platform_device_put(pdev);
392 return ERR_PTR(retval);
394 EXPORT_SYMBOL_GPL(platform_device_register_simple);
397 * platform_device_register_data
398 * @parent: parent device for the device we're adding
399 * @name: base name of the device we're adding
401 * @data: platform specific data for this platform device
402 * @size: size of platform specific data
404 * This function creates a simple platform device that requires minimal
405 * resource and memory management. Canned release function freeing memory
406 * allocated for the device allows drivers using such devices to be
407 * unloaded without waiting for the last reference to the device to be
410 struct platform_device *platform_device_register_data(
411 struct device *parent,
412 const char *name, int id,
413 const void *data, size_t size)
415 struct platform_device *pdev;
418 pdev = platform_device_alloc(name, id);
424 pdev->dev.parent = parent;
427 retval = platform_device_add_data(pdev, data, size);
432 retval = platform_device_add(pdev);
439 platform_device_put(pdev);
440 return ERR_PTR(retval);
443 static int platform_drv_probe(struct device *_dev)
445 struct platform_driver *drv = to_platform_driver(_dev->driver);
446 struct platform_device *dev = to_platform_device(_dev);
448 return drv->probe(dev);
451 static int platform_drv_probe_fail(struct device *_dev)
456 static int platform_drv_remove(struct device *_dev)
458 struct platform_driver *drv = to_platform_driver(_dev->driver);
459 struct platform_device *dev = to_platform_device(_dev);
461 return drv->remove(dev);
464 static void platform_drv_shutdown(struct device *_dev)
466 struct platform_driver *drv = to_platform_driver(_dev->driver);
467 struct platform_device *dev = to_platform_device(_dev);
473 * platform_driver_register
474 * @drv: platform driver structure
476 int platform_driver_register(struct platform_driver *drv)
478 drv->driver.bus = &platform_bus_type;
480 drv->driver.probe = platform_drv_probe;
482 drv->driver.remove = platform_drv_remove;
484 drv->driver.shutdown = platform_drv_shutdown;
485 if (drv->suspend || drv->resume)
486 pr_warning("Platform driver '%s' needs updating - please use "
487 "dev_pm_ops\n", drv->driver.name);
489 return driver_register(&drv->driver);
491 EXPORT_SYMBOL_GPL(platform_driver_register);
494 * platform_driver_unregister
495 * @drv: platform driver structure
497 void platform_driver_unregister(struct platform_driver *drv)
499 driver_unregister(&drv->driver);
501 EXPORT_SYMBOL_GPL(platform_driver_unregister);
504 * platform_driver_probe - register driver for non-hotpluggable device
505 * @drv: platform driver structure
506 * @probe: the driver probe routine, probably from an __init section
508 * Use this instead of platform_driver_register() when you know the device
509 * is not hotpluggable and has already been registered, and you want to
510 * remove its run-once probe() infrastructure from memory after the driver
511 * has bound to the device.
513 * One typical use for this would be with drivers for controllers integrated
514 * into system-on-chip processors, where the controller devices have been
515 * configured as part of board setup.
517 * Returns zero if the driver registered and bound to a device, else returns
518 * a negative error code and with the driver not registered.
520 int __init_or_module platform_driver_probe(struct platform_driver *drv,
521 int (*probe)(struct platform_device *))
525 /* temporary section violation during probe() */
527 retval = code = platform_driver_register(drv);
529 /* Fixup that section violation, being paranoid about code scanning
530 * the list of drivers in order to probe new devices. Check to see
531 * if the probe was successful, and make sure any forced probes of
534 spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
536 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
538 drv->driver.probe = platform_drv_probe_fail;
539 spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
542 platform_driver_unregister(drv);
545 EXPORT_SYMBOL_GPL(platform_driver_probe);
547 /* modalias support enables more hands-off userspace setup:
548 * (a) environment variable lets new-style hotplug events work once system is
549 * fully running: "modprobe $MODALIAS"
550 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
551 * mishandled before system is fully running: "modprobe $(cat modalias)"
553 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
556 struct platform_device *pdev = to_platform_device(dev);
557 int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
559 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
562 static struct device_attribute platform_dev_attrs[] = {
567 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
569 struct platform_device *pdev = to_platform_device(dev);
571 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
572 (pdev->id_entry) ? pdev->id_entry->name : pdev->name);
576 static const struct platform_device_id *platform_match_id(
577 struct platform_device_id *id,
578 struct platform_device *pdev)
580 while (id->name[0]) {
581 if (strcmp(pdev->name, id->name) == 0) {
591 * platform_match - bind platform device to platform driver.
595 * Platform device IDs are assumed to be encoded like this:
596 * "<name><instance>", where <name> is a short description of the type of
597 * device, like "pci" or "floppy", and <instance> is the enumerated
598 * instance of the device, like '0' or '42'. Driver IDs are simply
599 * "<name>". So, extract the <name> from the platform_device structure,
600 * and compare it against the name of the driver. Return whether they match
603 static int platform_match(struct device *dev, struct device_driver *drv)
605 struct platform_device *pdev = to_platform_device(dev);
606 struct platform_driver *pdrv = to_platform_driver(drv);
608 /* match against the id table first */
610 return platform_match_id(pdrv->id_table, pdev) != NULL;
612 /* fall-back to driver name match */
613 return (strcmp(pdev->name, drv->name) == 0);
616 #ifdef CONFIG_PM_SLEEP
618 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
620 struct platform_driver *pdrv = to_platform_driver(dev->driver);
621 struct platform_device *pdev = to_platform_device(dev);
624 if (dev->driver && pdrv->suspend)
625 ret = pdrv->suspend(pdev, mesg);
630 static int platform_legacy_suspend_late(struct device *dev, pm_message_t mesg)
632 struct platform_driver *pdrv = to_platform_driver(dev->driver);
633 struct platform_device *pdev = to_platform_device(dev);
636 if (dev->driver && pdrv->suspend_late)
637 ret = pdrv->suspend_late(pdev, mesg);
642 static int platform_legacy_resume_early(struct device *dev)
644 struct platform_driver *pdrv = to_platform_driver(dev->driver);
645 struct platform_device *pdev = to_platform_device(dev);
648 if (dev->driver && pdrv->resume_early)
649 ret = pdrv->resume_early(pdev);
654 static int platform_legacy_resume(struct device *dev)
656 struct platform_driver *pdrv = to_platform_driver(dev->driver);
657 struct platform_device *pdev = to_platform_device(dev);
660 if (dev->driver && pdrv->resume)
661 ret = pdrv->resume(pdev);
666 static int platform_pm_prepare(struct device *dev)
668 struct device_driver *drv = dev->driver;
671 if (drv && drv->pm && drv->pm->prepare)
672 ret = drv->pm->prepare(dev);
677 static void platform_pm_complete(struct device *dev)
679 struct device_driver *drv = dev->driver;
681 if (drv && drv->pm && drv->pm->complete)
682 drv->pm->complete(dev);
685 #ifdef CONFIG_SUSPEND
687 static int platform_pm_suspend(struct device *dev)
689 struct device_driver *drv = dev->driver;
696 if (drv->pm->suspend)
697 ret = drv->pm->suspend(dev);
699 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
705 static int platform_pm_suspend_noirq(struct device *dev)
707 struct device_driver *drv = dev->driver;
714 if (drv->pm->suspend_noirq)
715 ret = drv->pm->suspend_noirq(dev);
717 ret = platform_legacy_suspend_late(dev, PMSG_SUSPEND);
723 static int platform_pm_resume(struct device *dev)
725 struct device_driver *drv = dev->driver;
733 ret = drv->pm->resume(dev);
735 ret = platform_legacy_resume(dev);
741 static int platform_pm_resume_noirq(struct device *dev)
743 struct device_driver *drv = dev->driver;
750 if (drv->pm->resume_noirq)
751 ret = drv->pm->resume_noirq(dev);
753 ret = platform_legacy_resume_early(dev);
759 #else /* !CONFIG_SUSPEND */
761 #define platform_pm_suspend NULL
762 #define platform_pm_resume NULL
763 #define platform_pm_suspend_noirq NULL
764 #define platform_pm_resume_noirq NULL
766 #endif /* !CONFIG_SUSPEND */
768 #ifdef CONFIG_HIBERNATION
770 static int platform_pm_freeze(struct device *dev)
772 struct device_driver *drv = dev->driver;
780 ret = drv->pm->freeze(dev);
782 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
788 static int platform_pm_freeze_noirq(struct device *dev)
790 struct device_driver *drv = dev->driver;
797 if (drv->pm->freeze_noirq)
798 ret = drv->pm->freeze_noirq(dev);
800 ret = platform_legacy_suspend_late(dev, PMSG_FREEZE);
806 static int platform_pm_thaw(struct device *dev)
808 struct device_driver *drv = dev->driver;
816 ret = drv->pm->thaw(dev);
818 ret = platform_legacy_resume(dev);
824 static int platform_pm_thaw_noirq(struct device *dev)
826 struct device_driver *drv = dev->driver;
833 if (drv->pm->thaw_noirq)
834 ret = drv->pm->thaw_noirq(dev);
836 ret = platform_legacy_resume_early(dev);
842 static int platform_pm_poweroff(struct device *dev)
844 struct device_driver *drv = dev->driver;
851 if (drv->pm->poweroff)
852 ret = drv->pm->poweroff(dev);
854 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
860 static int platform_pm_poweroff_noirq(struct device *dev)
862 struct device_driver *drv = dev->driver;
869 if (drv->pm->poweroff_noirq)
870 ret = drv->pm->poweroff_noirq(dev);
872 ret = platform_legacy_suspend_late(dev, PMSG_HIBERNATE);
878 static int platform_pm_restore(struct device *dev)
880 struct device_driver *drv = dev->driver;
887 if (drv->pm->restore)
888 ret = drv->pm->restore(dev);
890 ret = platform_legacy_resume(dev);
896 static int platform_pm_restore_noirq(struct device *dev)
898 struct device_driver *drv = dev->driver;
905 if (drv->pm->restore_noirq)
906 ret = drv->pm->restore_noirq(dev);
908 ret = platform_legacy_resume_early(dev);
914 #else /* !CONFIG_HIBERNATION */
916 #define platform_pm_freeze NULL
917 #define platform_pm_thaw NULL
918 #define platform_pm_poweroff NULL
919 #define platform_pm_restore NULL
920 #define platform_pm_freeze_noirq NULL
921 #define platform_pm_thaw_noirq NULL
922 #define platform_pm_poweroff_noirq NULL
923 #define platform_pm_restore_noirq NULL
925 #endif /* !CONFIG_HIBERNATION */
927 static struct dev_pm_ops platform_dev_pm_ops = {
928 .prepare = platform_pm_prepare,
929 .complete = platform_pm_complete,
930 .suspend = platform_pm_suspend,
931 .resume = platform_pm_resume,
932 .freeze = platform_pm_freeze,
933 .thaw = platform_pm_thaw,
934 .poweroff = platform_pm_poweroff,
935 .restore = platform_pm_restore,
936 .suspend_noirq = platform_pm_suspend_noirq,
937 .resume_noirq = platform_pm_resume_noirq,
938 .freeze_noirq = platform_pm_freeze_noirq,
939 .thaw_noirq = platform_pm_thaw_noirq,
940 .poweroff_noirq = platform_pm_poweroff_noirq,
941 .restore_noirq = platform_pm_restore_noirq,
944 #define PLATFORM_PM_OPS_PTR (&platform_dev_pm_ops)
946 #else /* !CONFIG_PM_SLEEP */
948 #define PLATFORM_PM_OPS_PTR NULL
950 #endif /* !CONFIG_PM_SLEEP */
952 struct bus_type platform_bus_type = {
954 .dev_attrs = platform_dev_attrs,
955 .match = platform_match,
956 .uevent = platform_uevent,
957 .pm = PLATFORM_PM_OPS_PTR,
959 EXPORT_SYMBOL_GPL(platform_bus_type);
961 int __init platform_bus_init(void)
965 early_platform_cleanup();
967 error = device_register(&platform_bus);
970 error = bus_register(&platform_bus_type);
972 device_unregister(&platform_bus);
976 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
977 u64 dma_get_required_mask(struct device *dev)
979 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
980 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
983 if (!high_totalram) {
984 /* convert to mask just covering totalram */
985 low_totalram = (1 << (fls(low_totalram) - 1));
986 low_totalram += low_totalram - 1;
989 high_totalram = (1 << (fls(high_totalram) - 1));
990 high_totalram += high_totalram - 1;
991 mask = (((u64)high_totalram) << 32) + 0xffffffff;
995 EXPORT_SYMBOL_GPL(dma_get_required_mask);
998 static __initdata LIST_HEAD(early_platform_driver_list);
999 static __initdata LIST_HEAD(early_platform_device_list);
1002 * early_platform_driver_register
1003 * @epdrv: early_platform driver structure
1004 * @buf: string passed from early_param()
1006 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1009 unsigned long index;
1012 /* Simply add the driver to the end of the global list.
1013 * Drivers will by default be put on the list in compiled-in order.
1015 if (!epdrv->list.next) {
1016 INIT_LIST_HEAD(&epdrv->list);
1017 list_add_tail(&epdrv->list, &early_platform_driver_list);
1020 /* If the user has specified device then make sure the driver
1021 * gets prioritized. The driver of the last device specified on
1022 * command line will be put first on the list.
1024 n = strlen(epdrv->pdrv->driver.name);
1025 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1026 list_move(&epdrv->list, &early_platform_driver_list);
1028 if (!strcmp(buf, epdrv->pdrv->driver.name))
1029 epdrv->requested_id = -1;
1030 else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
1032 epdrv->requested_id = index;
1034 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1041 * early_platform_add_devices - add a numbers of early platform devices
1042 * @devs: array of early platform devices to add
1043 * @num: number of early platform devices in array
1045 void __init early_platform_add_devices(struct platform_device **devs, int num)
1050 /* simply add the devices to list */
1051 for (i = 0; i < num; i++) {
1052 dev = &devs[i]->dev;
1054 if (!dev->devres_head.next) {
1055 INIT_LIST_HEAD(&dev->devres_head);
1056 list_add_tail(&dev->devres_head,
1057 &early_platform_device_list);
1063 * early_platform_driver_register_all
1064 * @class_str: string to identify early platform driver class
1066 void __init early_platform_driver_register_all(char *class_str)
1068 /* The "class_str" parameter may or may not be present on the kernel
1069 * command line. If it is present then there may be more than one
1070 * matching parameter.
1072 * Since we register our early platform drivers using early_param()
1073 * we need to make sure that they also get registered in the case
1074 * when the parameter is missing from the kernel command line.
1076 * We use parse_early_options() to make sure the early_param() gets
1077 * called at least once. The early_param() may be called more than
1078 * once since the name of the preferred device may be specified on
1079 * the kernel command line. early_platform_driver_register() handles
1082 parse_early_options(class_str);
1086 * early_platform_match
1087 * @epdrv: early platform driver structure
1088 * @id: id to match against
1090 static __init struct platform_device *
1091 early_platform_match(struct early_platform_driver *epdrv, int id)
1093 struct platform_device *pd;
1095 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1096 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1104 * early_platform_left
1105 * @epdrv: early platform driver structure
1106 * @id: return true if id or above exists
1108 static __init int early_platform_left(struct early_platform_driver *epdrv,
1111 struct platform_device *pd;
1113 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1114 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1122 * early_platform_driver_probe_id
1123 * @class_str: string to identify early platform driver class
1124 * @id: id to match against
1125 * @nr_probe: number of platform devices to successfully probe before exiting
1127 static int __init early_platform_driver_probe_id(char *class_str,
1131 struct early_platform_driver *epdrv;
1132 struct platform_device *match;
1137 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1138 /* only use drivers matching our class_str */
1139 if (strcmp(class_str, epdrv->class_str))
1143 match_id = epdrv->requested_id;
1148 left += early_platform_left(epdrv, id);
1150 /* skip requested id */
1151 switch (epdrv->requested_id) {
1152 case EARLY_PLATFORM_ID_ERROR:
1153 case EARLY_PLATFORM_ID_UNSET:
1156 if (epdrv->requested_id == id)
1157 match_id = EARLY_PLATFORM_ID_UNSET;
1162 case EARLY_PLATFORM_ID_ERROR:
1163 pr_warning("%s: unable to parse %s parameter\n",
1164 class_str, epdrv->pdrv->driver.name);
1166 case EARLY_PLATFORM_ID_UNSET:
1170 match = early_platform_match(epdrv, match_id);
1174 if (epdrv->pdrv->probe(match))
1175 pr_warning("%s: unable to probe %s early.\n",
1176 class_str, match->name);
1192 * early_platform_driver_probe
1193 * @class_str: string to identify early platform driver class
1194 * @nr_probe: number of platform devices to successfully probe before exiting
1195 * @user_only: only probe user specified early platform devices
1197 int __init early_platform_driver_probe(char *class_str,
1204 for (i = -2; n < nr_probe; i++) {
1205 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1220 * early_platform_cleanup - clean up early platform code
1222 void __init early_platform_cleanup(void)
1224 struct platform_device *pd, *pd2;
1226 /* clean up the devres list used to chain devices */
1227 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1229 list_del(&pd->dev.devres_head);
1230 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));