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];
314 unsigned long type = resource_type(r);
316 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
322 EXPORT_SYMBOL_GPL(platform_device_add);
325 * platform_device_del - remove a platform-level device
326 * @pdev: platform device we're removing
328 * Note that this function will also release all memory- and port-based
329 * resources owned by the device (@dev->resource). This function must
330 * _only_ be externally called in error cases. All other usage is a bug.
332 void platform_device_del(struct platform_device *pdev)
337 device_del(&pdev->dev);
339 for (i = 0; i < pdev->num_resources; i++) {
340 struct resource *r = &pdev->resource[i];
341 unsigned long type = resource_type(r);
343 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
348 EXPORT_SYMBOL_GPL(platform_device_del);
351 * platform_device_register - add a platform-level device
352 * @pdev: platform device we're adding
354 int platform_device_register(struct platform_device *pdev)
356 device_initialize(&pdev->dev);
357 arch_setup_pdev_archdata(pdev);
358 return platform_device_add(pdev);
360 EXPORT_SYMBOL_GPL(platform_device_register);
363 * platform_device_unregister - unregister a platform-level device
364 * @pdev: platform device we're unregistering
366 * Unregistration is done in 2 steps. First we release all resources
367 * and remove it from the subsystem, then we drop reference count by
368 * calling platform_device_put().
370 void platform_device_unregister(struct platform_device *pdev)
372 platform_device_del(pdev);
373 platform_device_put(pdev);
375 EXPORT_SYMBOL_GPL(platform_device_unregister);
378 * platform_device_register_resndata - add a platform-level device with
379 * resources and platform-specific data
381 * @parent: parent device for the device we're adding
382 * @name: base name of the device we're adding
384 * @res: set of resources that needs to be allocated for the device
385 * @num: number of resources
386 * @data: platform specific data for this platform device
387 * @size: size of platform specific data
389 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
391 struct platform_device *platform_device_register_resndata(
392 struct device *parent,
393 const char *name, int id,
394 const struct resource *res, unsigned int num,
395 const void *data, size_t size)
398 struct platform_device *pdev;
400 pdev = platform_device_alloc(name, id);
404 pdev->dev.parent = parent;
406 ret = platform_device_add_resources(pdev, res, num);
410 ret = platform_device_add_data(pdev, data, size);
414 ret = platform_device_add(pdev);
417 platform_device_put(pdev);
423 EXPORT_SYMBOL_GPL(platform_device_register_resndata);
425 static int platform_drv_probe(struct device *_dev)
427 struct platform_driver *drv = to_platform_driver(_dev->driver);
428 struct platform_device *dev = to_platform_device(_dev);
430 return drv->probe(dev);
433 static int platform_drv_probe_fail(struct device *_dev)
438 static int platform_drv_remove(struct device *_dev)
440 struct platform_driver *drv = to_platform_driver(_dev->driver);
441 struct platform_device *dev = to_platform_device(_dev);
443 return drv->remove(dev);
446 static void platform_drv_shutdown(struct device *_dev)
448 struct platform_driver *drv = to_platform_driver(_dev->driver);
449 struct platform_device *dev = to_platform_device(_dev);
455 * platform_driver_register - register a driver for platform-level devices
456 * @drv: platform driver structure
458 int platform_driver_register(struct platform_driver *drv)
460 drv->driver.bus = &platform_bus_type;
462 drv->driver.probe = platform_drv_probe;
464 drv->driver.remove = platform_drv_remove;
466 drv->driver.shutdown = platform_drv_shutdown;
468 return driver_register(&drv->driver);
470 EXPORT_SYMBOL_GPL(platform_driver_register);
473 * platform_driver_unregister - unregister a driver for platform-level devices
474 * @drv: platform driver structure
476 void platform_driver_unregister(struct platform_driver *drv)
478 driver_unregister(&drv->driver);
480 EXPORT_SYMBOL_GPL(platform_driver_unregister);
483 * platform_driver_probe - register driver for non-hotpluggable device
484 * @drv: platform driver structure
485 * @probe: the driver probe routine, probably from an __init section
487 * Use this instead of platform_driver_register() when you know the device
488 * is not hotpluggable and has already been registered, and you want to
489 * remove its run-once probe() infrastructure from memory after the driver
490 * has bound to the device.
492 * One typical use for this would be with drivers for controllers integrated
493 * into system-on-chip processors, where the controller devices have been
494 * configured as part of board setup.
496 * Returns zero if the driver registered and bound to a device, else returns
497 * a negative error code and with the driver not registered.
499 int __init_or_module platform_driver_probe(struct platform_driver *drv,
500 int (*probe)(struct platform_device *))
504 /* make sure driver won't have bind/unbind attributes */
505 drv->driver.suppress_bind_attrs = true;
507 /* temporary section violation during probe() */
509 retval = code = platform_driver_register(drv);
512 * Fixup that section violation, being paranoid about code scanning
513 * the list of drivers in order to probe new devices. Check to see
514 * if the probe was successful, and make sure any forced probes of
517 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
519 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
521 drv->driver.probe = platform_drv_probe_fail;
522 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
525 platform_driver_unregister(drv);
528 EXPORT_SYMBOL_GPL(platform_driver_probe);
531 * platform_create_bundle - register driver and create corresponding device
532 * @driver: platform driver structure
533 * @probe: the driver probe routine, probably from an __init section
534 * @res: set of resources that needs to be allocated for the device
535 * @n_res: number of resources
536 * @data: platform specific data for this platform device
537 * @size: size of platform specific data
539 * Use this in legacy-style modules that probe hardware directly and
540 * register a single platform device and corresponding platform driver.
542 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
544 struct platform_device * __init_or_module platform_create_bundle(
545 struct platform_driver *driver,
546 int (*probe)(struct platform_device *),
547 struct resource *res, unsigned int n_res,
548 const void *data, size_t size)
550 struct platform_device *pdev;
553 pdev = platform_device_alloc(driver->driver.name, -1);
559 error = platform_device_add_resources(pdev, res, n_res);
563 error = platform_device_add_data(pdev, data, size);
567 error = platform_device_add(pdev);
571 error = platform_driver_probe(driver, probe);
578 platform_device_del(pdev);
580 platform_device_put(pdev);
582 return ERR_PTR(error);
584 EXPORT_SYMBOL_GPL(platform_create_bundle);
586 /* modalias support enables more hands-off userspace setup:
587 * (a) environment variable lets new-style hotplug events work once system is
588 * fully running: "modprobe $MODALIAS"
589 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
590 * mishandled before system is fully running: "modprobe $(cat modalias)"
592 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
595 struct platform_device *pdev = to_platform_device(dev);
596 int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
598 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
601 static struct device_attribute platform_dev_attrs[] = {
606 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
608 struct platform_device *pdev = to_platform_device(dev);
611 /* Some devices have extra OF data and an OF-style MODALIAS */
612 rc = of_device_uevent(dev,env);
616 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
617 (pdev->id_entry) ? pdev->id_entry->name : pdev->name);
621 static const struct platform_device_id *platform_match_id(
622 const struct platform_device_id *id,
623 struct platform_device *pdev)
625 while (id->name[0]) {
626 if (strcmp(pdev->name, id->name) == 0) {
636 * platform_match - bind platform device to platform driver.
640 * Platform device IDs are assumed to be encoded like this:
641 * "<name><instance>", where <name> is a short description of the type of
642 * device, like "pci" or "floppy", and <instance> is the enumerated
643 * instance of the device, like '0' or '42'. Driver IDs are simply
644 * "<name>". So, extract the <name> from the platform_device structure,
645 * and compare it against the name of the driver. Return whether they match
648 static int platform_match(struct device *dev, struct device_driver *drv)
650 struct platform_device *pdev = to_platform_device(dev);
651 struct platform_driver *pdrv = to_platform_driver(drv);
653 /* Attempt an OF style match first */
654 if (of_driver_match_device(dev, drv))
657 /* Then try to match against the id table */
659 return platform_match_id(pdrv->id_table, pdev) != NULL;
661 /* fall-back to driver name match */
662 return (strcmp(pdev->name, drv->name) == 0);
665 #ifdef CONFIG_PM_SLEEP
667 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
669 struct platform_driver *pdrv = to_platform_driver(dev->driver);
670 struct platform_device *pdev = to_platform_device(dev);
673 if (dev->driver && pdrv->suspend)
674 ret = pdrv->suspend(pdev, mesg);
679 static int platform_legacy_resume(struct device *dev)
681 struct platform_driver *pdrv = to_platform_driver(dev->driver);
682 struct platform_device *pdev = to_platform_device(dev);
685 if (dev->driver && pdrv->resume)
686 ret = pdrv->resume(pdev);
691 int platform_pm_prepare(struct device *dev)
693 struct device_driver *drv = dev->driver;
696 if (drv && drv->pm && drv->pm->prepare)
697 ret = drv->pm->prepare(dev);
702 void platform_pm_complete(struct device *dev)
704 struct device_driver *drv = dev->driver;
706 if (drv && drv->pm && drv->pm->complete)
707 drv->pm->complete(dev);
710 #endif /* CONFIG_PM_SLEEP */
712 #ifdef CONFIG_SUSPEND
714 int platform_pm_suspend(struct device *dev)
716 struct device_driver *drv = dev->driver;
723 if (drv->pm->suspend)
724 ret = drv->pm->suspend(dev);
726 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
732 int platform_pm_suspend_noirq(struct device *dev)
734 struct device_driver *drv = dev->driver;
741 if (drv->pm->suspend_noirq)
742 ret = drv->pm->suspend_noirq(dev);
748 int platform_pm_resume(struct device *dev)
750 struct device_driver *drv = dev->driver;
758 ret = drv->pm->resume(dev);
760 ret = platform_legacy_resume(dev);
766 int platform_pm_resume_noirq(struct device *dev)
768 struct device_driver *drv = dev->driver;
775 if (drv->pm->resume_noirq)
776 ret = drv->pm->resume_noirq(dev);
782 #endif /* CONFIG_SUSPEND */
784 #ifdef CONFIG_HIBERNATE_CALLBACKS
786 int platform_pm_freeze(struct device *dev)
788 struct device_driver *drv = dev->driver;
796 ret = drv->pm->freeze(dev);
798 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
804 int platform_pm_freeze_noirq(struct device *dev)
806 struct device_driver *drv = dev->driver;
813 if (drv->pm->freeze_noirq)
814 ret = drv->pm->freeze_noirq(dev);
820 int platform_pm_thaw(struct device *dev)
822 struct device_driver *drv = dev->driver;
830 ret = drv->pm->thaw(dev);
832 ret = platform_legacy_resume(dev);
838 int platform_pm_thaw_noirq(struct device *dev)
840 struct device_driver *drv = dev->driver;
847 if (drv->pm->thaw_noirq)
848 ret = drv->pm->thaw_noirq(dev);
854 int platform_pm_poweroff(struct device *dev)
856 struct device_driver *drv = dev->driver;
863 if (drv->pm->poweroff)
864 ret = drv->pm->poweroff(dev);
866 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
872 int platform_pm_poweroff_noirq(struct device *dev)
874 struct device_driver *drv = dev->driver;
881 if (drv->pm->poweroff_noirq)
882 ret = drv->pm->poweroff_noirq(dev);
888 int platform_pm_restore(struct device *dev)
890 struct device_driver *drv = dev->driver;
897 if (drv->pm->restore)
898 ret = drv->pm->restore(dev);
900 ret = platform_legacy_resume(dev);
906 int platform_pm_restore_noirq(struct device *dev)
908 struct device_driver *drv = dev->driver;
915 if (drv->pm->restore_noirq)
916 ret = drv->pm->restore_noirq(dev);
922 #endif /* CONFIG_HIBERNATE_CALLBACKS */
924 static const struct dev_pm_ops platform_dev_pm_ops = {
925 .runtime_suspend = pm_generic_runtime_suspend,
926 .runtime_resume = pm_generic_runtime_resume,
927 .runtime_idle = pm_generic_runtime_idle,
928 USE_PLATFORM_PM_SLEEP_OPS
931 struct bus_type platform_bus_type = {
933 .dev_attrs = platform_dev_attrs,
934 .match = platform_match,
935 .uevent = platform_uevent,
936 .pm = &platform_dev_pm_ops,
938 EXPORT_SYMBOL_GPL(platform_bus_type);
940 int __init platform_bus_init(void)
944 early_platform_cleanup();
946 error = device_register(&platform_bus);
949 error = bus_register(&platform_bus_type);
951 device_unregister(&platform_bus);
955 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
956 u64 dma_get_required_mask(struct device *dev)
958 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
959 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
962 if (!high_totalram) {
963 /* convert to mask just covering totalram */
964 low_totalram = (1 << (fls(low_totalram) - 1));
965 low_totalram += low_totalram - 1;
968 high_totalram = (1 << (fls(high_totalram) - 1));
969 high_totalram += high_totalram - 1;
970 mask = (((u64)high_totalram) << 32) + 0xffffffff;
974 EXPORT_SYMBOL_GPL(dma_get_required_mask);
977 static __initdata LIST_HEAD(early_platform_driver_list);
978 static __initdata LIST_HEAD(early_platform_device_list);
981 * early_platform_driver_register - register early platform driver
982 * @epdrv: early_platform driver structure
983 * @buf: string passed from early_param()
985 * Helper function for early_platform_init() / early_platform_init_buffer()
987 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
993 /* Simply add the driver to the end of the global list.
994 * Drivers will by default be put on the list in compiled-in order.
996 if (!epdrv->list.next) {
997 INIT_LIST_HEAD(&epdrv->list);
998 list_add_tail(&epdrv->list, &early_platform_driver_list);
1001 /* If the user has specified device then make sure the driver
1002 * gets prioritized. The driver of the last device specified on
1003 * command line will be put first on the list.
1005 n = strlen(epdrv->pdrv->driver.name);
1006 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1007 list_move(&epdrv->list, &early_platform_driver_list);
1009 /* Allow passing parameters after device name */
1010 if (buf[n] == '\0' || buf[n] == ',')
1011 epdrv->requested_id = -1;
1013 epdrv->requested_id = simple_strtoul(&buf[n + 1],
1016 if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1017 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1020 n += strcspn(&buf[n + 1], ",") + 1;
1026 if (epdrv->bufsize) {
1027 memcpy(epdrv->buffer, &buf[n],
1028 min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1029 epdrv->buffer[epdrv->bufsize - 1] = '\0';
1037 * early_platform_add_devices - adds a number of early platform devices
1038 * @devs: array of early platform devices to add
1039 * @num: number of early platform devices in array
1041 * Used by early architecture code to register early platform devices and
1042 * their platform data.
1044 void __init early_platform_add_devices(struct platform_device **devs, int num)
1049 /* simply add the devices to list */
1050 for (i = 0; i < num; i++) {
1051 dev = &devs[i]->dev;
1053 if (!dev->devres_head.next) {
1054 INIT_LIST_HEAD(&dev->devres_head);
1055 list_add_tail(&dev->devres_head,
1056 &early_platform_device_list);
1062 * early_platform_driver_register_all - register early platform drivers
1063 * @class_str: string to identify early platform driver class
1065 * Used by architecture code to register all early platform drivers
1066 * for a certain class. If omitted then only early platform drivers
1067 * with matching kernel command line class parameters will be registered.
1069 void __init early_platform_driver_register_all(char *class_str)
1071 /* The "class_str" parameter may or may not be present on the kernel
1072 * command line. If it is present then there may be more than one
1073 * matching parameter.
1075 * Since we register our early platform drivers using early_param()
1076 * we need to make sure that they also get registered in the case
1077 * when the parameter is missing from the kernel command line.
1079 * We use parse_early_options() to make sure the early_param() gets
1080 * called at least once. The early_param() may be called more than
1081 * once since the name of the preferred device may be specified on
1082 * the kernel command line. early_platform_driver_register() handles
1085 parse_early_options(class_str);
1089 * early_platform_match - find early platform device matching driver
1090 * @epdrv: early platform driver structure
1091 * @id: id to match against
1093 static __init struct platform_device *
1094 early_platform_match(struct early_platform_driver *epdrv, int id)
1096 struct platform_device *pd;
1098 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1099 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1107 * early_platform_left - check if early platform driver has matching devices
1108 * @epdrv: early platform driver structure
1109 * @id: return true if id or above exists
1111 static __init int early_platform_left(struct early_platform_driver *epdrv,
1114 struct platform_device *pd;
1116 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1117 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1125 * early_platform_driver_probe_id - probe drivers matching class_str and id
1126 * @class_str: string to identify early platform driver class
1127 * @id: id to match against
1128 * @nr_probe: number of platform devices to successfully probe before exiting
1130 static int __init early_platform_driver_probe_id(char *class_str,
1134 struct early_platform_driver *epdrv;
1135 struct platform_device *match;
1140 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1141 /* only use drivers matching our class_str */
1142 if (strcmp(class_str, epdrv->class_str))
1146 match_id = epdrv->requested_id;
1151 left += early_platform_left(epdrv, id);
1153 /* skip requested id */
1154 switch (epdrv->requested_id) {
1155 case EARLY_PLATFORM_ID_ERROR:
1156 case EARLY_PLATFORM_ID_UNSET:
1159 if (epdrv->requested_id == id)
1160 match_id = EARLY_PLATFORM_ID_UNSET;
1165 case EARLY_PLATFORM_ID_ERROR:
1166 pr_warning("%s: unable to parse %s parameter\n",
1167 class_str, epdrv->pdrv->driver.name);
1169 case EARLY_PLATFORM_ID_UNSET:
1173 match = early_platform_match(epdrv, match_id);
1178 * Set up a sensible init_name to enable
1179 * dev_name() and others to be used before the
1180 * rest of the driver core is initialized.
1182 if (!match->dev.init_name && slab_is_available()) {
1183 if (match->id != -1)
1184 match->dev.init_name =
1185 kasprintf(GFP_KERNEL, "%s.%d",
1189 match->dev.init_name =
1190 kasprintf(GFP_KERNEL, "%s",
1193 if (!match->dev.init_name)
1197 if (epdrv->pdrv->probe(match))
1198 pr_warning("%s: unable to probe %s early.\n",
1199 class_str, match->name);
1215 * early_platform_driver_probe - probe a class of registered drivers
1216 * @class_str: string to identify early platform driver class
1217 * @nr_probe: number of platform devices to successfully probe before exiting
1218 * @user_only: only probe user specified early platform devices
1220 * Used by architecture code to probe registered early platform drivers
1221 * within a certain class. For probe to happen a registered early platform
1222 * device matching a registered early platform driver is needed.
1224 int __init early_platform_driver_probe(char *class_str,
1231 for (i = -2; n < nr_probe; i++) {
1232 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1247 * early_platform_cleanup - clean up early platform code
1249 void __init early_platform_cleanup(void)
1251 struct platform_device *pd, *pd2;
1253 /* clean up the devres list used to chain devices */
1254 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1256 list_del(&pd->dev.devres_head);
1257 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));