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>
23 #include <linux/idr.h>
24 #include <linux/acpi.h>
27 #include "power/power.h"
29 /* For automatically allocated device IDs */
30 static DEFINE_IDA(platform_devid_ida);
32 #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \
35 struct device platform_bus = {
36 .init_name = "platform",
38 EXPORT_SYMBOL_GPL(platform_bus);
41 * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
42 * @pdev: platform device
44 * This is called before platform_device_add() such that any pdev_archdata may
45 * be setup before the platform_notifier is called. So if a user needs to
46 * manipulate any relevant information in the pdev_archdata they can do:
48 * platform_device_alloc()
50 * platform_device_add()
52 * And if they don't care they can just call platform_device_register() and
53 * everything will just work out.
55 void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
60 * platform_get_resource - get a resource for a device
61 * @dev: platform device
62 * @type: resource type
63 * @num: resource index
65 struct resource *platform_get_resource(struct platform_device *dev,
66 unsigned int type, unsigned int num)
70 for (i = 0; i < dev->num_resources; i++) {
71 struct resource *r = &dev->resource[i];
73 if (type == resource_type(r) && num-- == 0)
78 EXPORT_SYMBOL_GPL(platform_get_resource);
81 * platform_get_irq - get an IRQ for a device
82 * @dev: platform device
83 * @num: IRQ number index
85 int platform_get_irq(struct platform_device *dev, unsigned int num)
88 /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
89 if (!dev || num >= dev->archdata.num_irqs)
91 return dev->archdata.irqs[num];
93 struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
95 return r ? r->start : -ENXIO;
98 EXPORT_SYMBOL_GPL(platform_get_irq);
101 * platform_get_resource_byname - get a resource for a device by name
102 * @dev: platform device
103 * @type: resource type
104 * @name: resource name
106 struct resource *platform_get_resource_byname(struct platform_device *dev,
112 for (i = 0; i < dev->num_resources; i++) {
113 struct resource *r = &dev->resource[i];
115 if (unlikely(!r->name))
118 if (type == resource_type(r) && !strcmp(r->name, name))
123 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
126 * platform_get_irq_byname - get an IRQ for a device by name
127 * @dev: platform device
130 int platform_get_irq_byname(struct platform_device *dev, const char *name)
132 struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
135 return r ? r->start : -ENXIO;
137 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
140 * platform_add_devices - add a numbers of platform devices
141 * @devs: array of platform devices to add
142 * @num: number of platform devices in array
144 int platform_add_devices(struct platform_device **devs, int num)
148 for (i = 0; i < num; i++) {
149 ret = platform_device_register(devs[i]);
152 platform_device_unregister(devs[i]);
159 EXPORT_SYMBOL_GPL(platform_add_devices);
161 struct platform_object {
162 struct platform_device pdev;
167 * platform_device_put - destroy a platform device
168 * @pdev: platform device to free
170 * Free all memory associated with a platform device. This function must
171 * _only_ be externally called in error cases. All other usage is a bug.
173 void platform_device_put(struct platform_device *pdev)
176 put_device(&pdev->dev);
178 EXPORT_SYMBOL_GPL(platform_device_put);
180 static void platform_device_release(struct device *dev)
182 struct platform_object *pa = container_of(dev, struct platform_object,
185 of_device_node_put(&pa->pdev.dev);
186 kfree(pa->pdev.dev.platform_data);
187 kfree(pa->pdev.mfd_cell);
188 kfree(pa->pdev.resource);
193 * platform_device_alloc - create a platform device
194 * @name: base name of the device we're adding
197 * Create a platform device object which can have other objects attached
198 * to it, and which will have attached objects freed when it is released.
200 struct platform_device *platform_device_alloc(const char *name, int id)
202 struct platform_object *pa;
204 pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
206 strcpy(pa->name, name);
207 pa->pdev.name = pa->name;
209 device_initialize(&pa->pdev.dev);
210 pa->pdev.dev.release = platform_device_release;
211 arch_setup_pdev_archdata(&pa->pdev);
214 return pa ? &pa->pdev : NULL;
216 EXPORT_SYMBOL_GPL(platform_device_alloc);
219 * platform_device_add_resources - add resources to a platform device
220 * @pdev: platform device allocated by platform_device_alloc to add resources to
221 * @res: set of resources that needs to be allocated for the device
222 * @num: number of resources
224 * Add a copy of the resources to the platform device. The memory
225 * associated with the resources will be freed when the platform device is
228 int platform_device_add_resources(struct platform_device *pdev,
229 const struct resource *res, unsigned int num)
231 struct resource *r = NULL;
234 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
239 kfree(pdev->resource);
241 pdev->num_resources = num;
244 EXPORT_SYMBOL_GPL(platform_device_add_resources);
247 * platform_device_add_data - add platform-specific data to a platform device
248 * @pdev: platform device allocated by platform_device_alloc to add resources to
249 * @data: platform specific data for this platform device
250 * @size: size of platform specific data
252 * Add a copy of platform specific data to the platform device's
253 * platform_data pointer. The memory associated with the platform data
254 * will be freed when the platform device is released.
256 int platform_device_add_data(struct platform_device *pdev, const void *data,
262 d = kmemdup(data, size, GFP_KERNEL);
267 kfree(pdev->dev.platform_data);
268 pdev->dev.platform_data = d;
271 EXPORT_SYMBOL_GPL(platform_device_add_data);
274 * platform_device_add - add a platform device to device hierarchy
275 * @pdev: platform device we're adding
277 * This is part 2 of platform_device_register(), though may be called
278 * separately _iff_ pdev was allocated by platform_device_alloc().
280 int platform_device_add(struct platform_device *pdev)
287 if (!pdev->dev.parent)
288 pdev->dev.parent = &platform_bus;
290 pdev->dev.bus = &platform_bus_type;
294 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
296 case PLATFORM_DEVID_NONE:
297 dev_set_name(&pdev->dev, "%s", pdev->name);
299 case PLATFORM_DEVID_AUTO:
301 * Automatically allocated device ID. We mark it as such so
302 * that we remember it must be freed, and we append a suffix
303 * to avoid namespace collision with explicit IDs.
305 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
309 pdev->id_auto = true;
310 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
314 for (i = 0; i < pdev->num_resources; i++) {
315 struct resource *p, *r = &pdev->resource[i];
318 r->name = dev_name(&pdev->dev);
322 if (resource_type(r) == IORESOURCE_MEM)
324 else if (resource_type(r) == IORESOURCE_IO)
325 p = &ioport_resource;
328 if (p && insert_resource(p, r)) {
330 "%s: failed to claim resource %d\n",
331 dev_name(&pdev->dev), i);
337 pr_debug("Registering platform device '%s'. Parent at %s\n",
338 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
340 ret = device_add(&pdev->dev);
346 ida_simple_remove(&platform_devid_ida, pdev->id);
347 pdev->id = PLATFORM_DEVID_AUTO;
351 struct resource *r = &pdev->resource[i];
352 unsigned long type = resource_type(r);
354 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
361 EXPORT_SYMBOL_GPL(platform_device_add);
364 * platform_device_del - remove a platform-level device
365 * @pdev: platform device we're removing
367 * Note that this function will also release all memory- and port-based
368 * resources owned by the device (@dev->resource). This function must
369 * _only_ be externally called in error cases. All other usage is a bug.
371 void platform_device_del(struct platform_device *pdev)
376 device_del(&pdev->dev);
379 ida_simple_remove(&platform_devid_ida, pdev->id);
380 pdev->id = PLATFORM_DEVID_AUTO;
383 for (i = 0; i < pdev->num_resources; i++) {
384 struct resource *r = &pdev->resource[i];
385 unsigned long type = resource_type(r);
387 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
392 EXPORT_SYMBOL_GPL(platform_device_del);
395 * platform_device_register - add a platform-level device
396 * @pdev: platform device we're adding
398 int platform_device_register(struct platform_device *pdev)
400 device_initialize(&pdev->dev);
401 arch_setup_pdev_archdata(pdev);
402 return platform_device_add(pdev);
404 EXPORT_SYMBOL_GPL(platform_device_register);
407 * platform_device_unregister - unregister a platform-level device
408 * @pdev: platform device we're unregistering
410 * Unregistration is done in 2 steps. First we release all resources
411 * and remove it from the subsystem, then we drop reference count by
412 * calling platform_device_put().
414 void platform_device_unregister(struct platform_device *pdev)
416 platform_device_del(pdev);
417 platform_device_put(pdev);
419 EXPORT_SYMBOL_GPL(platform_device_unregister);
422 * platform_device_register_full - add a platform-level device with
423 * resources and platform-specific data
425 * @pdevinfo: data used to create device
427 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
429 struct platform_device *platform_device_register_full(
430 const struct platform_device_info *pdevinfo)
433 struct platform_device *pdev;
435 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
439 pdev->dev.parent = pdevinfo->parent;
440 ACPI_HANDLE_SET(&pdev->dev, pdevinfo->acpi_node.handle);
442 if (pdevinfo->dma_mask) {
444 * This memory isn't freed when the device is put,
445 * I don't have a nice idea for that though. Conceptually
446 * dma_mask in struct device should not be a pointer.
447 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
450 kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
451 if (!pdev->dev.dma_mask)
454 *pdev->dev.dma_mask = pdevinfo->dma_mask;
455 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
458 ret = platform_device_add_resources(pdev,
459 pdevinfo->res, pdevinfo->num_res);
463 ret = platform_device_add_data(pdev,
464 pdevinfo->data, pdevinfo->size_data);
468 ret = platform_device_add(pdev);
471 ACPI_HANDLE_SET(&pdev->dev, NULL);
472 kfree(pdev->dev.dma_mask);
475 platform_device_put(pdev);
481 EXPORT_SYMBOL_GPL(platform_device_register_full);
483 static int platform_drv_probe(struct device *_dev)
485 struct platform_driver *drv = to_platform_driver(_dev->driver);
486 struct platform_device *dev = to_platform_device(_dev);
489 if (ACPI_HANDLE(_dev))
490 acpi_dev_pm_attach(_dev, true);
492 ret = drv->probe(dev);
493 if (ret && ACPI_HANDLE(_dev))
494 acpi_dev_pm_detach(_dev, true);
499 static int platform_drv_probe_fail(struct device *_dev)
504 static int platform_drv_remove(struct device *_dev)
506 struct platform_driver *drv = to_platform_driver(_dev->driver);
507 struct platform_device *dev = to_platform_device(_dev);
510 ret = drv->remove(dev);
511 if (ACPI_HANDLE(_dev))
512 acpi_dev_pm_detach(_dev, true);
517 static void platform_drv_shutdown(struct device *_dev)
519 struct platform_driver *drv = to_platform_driver(_dev->driver);
520 struct platform_device *dev = to_platform_device(_dev);
523 if (ACPI_HANDLE(_dev))
524 acpi_dev_pm_detach(_dev, true);
528 * platform_driver_register - register a driver for platform-level devices
529 * @drv: platform driver structure
531 int platform_driver_register(struct platform_driver *drv)
533 drv->driver.bus = &platform_bus_type;
535 drv->driver.probe = platform_drv_probe;
537 drv->driver.remove = platform_drv_remove;
539 drv->driver.shutdown = platform_drv_shutdown;
541 return driver_register(&drv->driver);
543 EXPORT_SYMBOL_GPL(platform_driver_register);
546 * platform_driver_unregister - unregister a driver for platform-level devices
547 * @drv: platform driver structure
549 void platform_driver_unregister(struct platform_driver *drv)
551 driver_unregister(&drv->driver);
553 EXPORT_SYMBOL_GPL(platform_driver_unregister);
556 * platform_driver_probe - register driver for non-hotpluggable device
557 * @drv: platform driver structure
558 * @probe: the driver probe routine, probably from an __init section
560 * Use this instead of platform_driver_register() when you know the device
561 * is not hotpluggable and has already been registered, and you want to
562 * remove its run-once probe() infrastructure from memory after the driver
563 * has bound to the device.
565 * One typical use for this would be with drivers for controllers integrated
566 * into system-on-chip processors, where the controller devices have been
567 * configured as part of board setup.
569 * Returns zero if the driver registered and bound to a device, else returns
570 * a negative error code and with the driver not registered.
572 int __init_or_module platform_driver_probe(struct platform_driver *drv,
573 int (*probe)(struct platform_device *))
577 /* make sure driver won't have bind/unbind attributes */
578 drv->driver.suppress_bind_attrs = true;
580 /* temporary section violation during probe() */
582 retval = code = platform_driver_register(drv);
585 * Fixup that section violation, being paranoid about code scanning
586 * the list of drivers in order to probe new devices. Check to see
587 * if the probe was successful, and make sure any forced probes of
590 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
592 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
594 drv->driver.probe = platform_drv_probe_fail;
595 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
598 platform_driver_unregister(drv);
601 EXPORT_SYMBOL_GPL(platform_driver_probe);
604 * platform_create_bundle - register driver and create corresponding device
605 * @driver: platform driver structure
606 * @probe: the driver probe routine, probably from an __init section
607 * @res: set of resources that needs to be allocated for the device
608 * @n_res: number of resources
609 * @data: platform specific data for this platform device
610 * @size: size of platform specific data
612 * Use this in legacy-style modules that probe hardware directly and
613 * register a single platform device and corresponding platform driver.
615 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
617 struct platform_device * __init_or_module platform_create_bundle(
618 struct platform_driver *driver,
619 int (*probe)(struct platform_device *),
620 struct resource *res, unsigned int n_res,
621 const void *data, size_t size)
623 struct platform_device *pdev;
626 pdev = platform_device_alloc(driver->driver.name, -1);
632 error = platform_device_add_resources(pdev, res, n_res);
636 error = platform_device_add_data(pdev, data, size);
640 error = platform_device_add(pdev);
644 error = platform_driver_probe(driver, probe);
651 platform_device_del(pdev);
653 platform_device_put(pdev);
655 return ERR_PTR(error);
657 EXPORT_SYMBOL_GPL(platform_create_bundle);
659 /* modalias support enables more hands-off userspace setup:
660 * (a) environment variable lets new-style hotplug events work once system is
661 * fully running: "modprobe $MODALIAS"
662 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
663 * mishandled before system is fully running: "modprobe $(cat modalias)"
665 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
668 struct platform_device *pdev = to_platform_device(dev);
669 int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
671 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
674 static struct device_attribute platform_dev_attrs[] = {
679 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
681 struct platform_device *pdev = to_platform_device(dev);
684 /* Some devices have extra OF data and an OF-style MODALIAS */
685 rc = of_device_uevent_modalias(dev,env);
689 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
694 static const struct platform_device_id *platform_match_id(
695 const struct platform_device_id *id,
696 struct platform_device *pdev)
698 while (id->name[0]) {
699 if (strcmp(pdev->name, id->name) == 0) {
709 * platform_match - bind platform device to platform driver.
713 * Platform device IDs are assumed to be encoded like this:
714 * "<name><instance>", where <name> is a short description of the type of
715 * device, like "pci" or "floppy", and <instance> is the enumerated
716 * instance of the device, like '0' or '42'. Driver IDs are simply
717 * "<name>". So, extract the <name> from the platform_device structure,
718 * and compare it against the name of the driver. Return whether they match
721 static int platform_match(struct device *dev, struct device_driver *drv)
723 struct platform_device *pdev = to_platform_device(dev);
724 struct platform_driver *pdrv = to_platform_driver(drv);
726 /* Attempt an OF style match first */
727 if (of_driver_match_device(dev, drv))
730 /* Then try ACPI style match */
731 if (acpi_driver_match_device(dev, drv))
734 /* Then try to match against the id table */
736 return platform_match_id(pdrv->id_table, pdev) != NULL;
738 /* fall-back to driver name match */
739 return (strcmp(pdev->name, drv->name) == 0);
742 #ifdef CONFIG_PM_SLEEP
744 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
746 struct platform_driver *pdrv = to_platform_driver(dev->driver);
747 struct platform_device *pdev = to_platform_device(dev);
750 if (dev->driver && pdrv->suspend)
751 ret = pdrv->suspend(pdev, mesg);
756 static int platform_legacy_resume(struct device *dev)
758 struct platform_driver *pdrv = to_platform_driver(dev->driver);
759 struct platform_device *pdev = to_platform_device(dev);
762 if (dev->driver && pdrv->resume)
763 ret = pdrv->resume(pdev);
768 #endif /* CONFIG_PM_SLEEP */
770 #ifdef CONFIG_SUSPEND
772 int platform_pm_suspend(struct device *dev)
774 struct device_driver *drv = dev->driver;
781 if (drv->pm->suspend)
782 ret = drv->pm->suspend(dev);
784 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
790 int platform_pm_resume(struct device *dev)
792 struct device_driver *drv = dev->driver;
800 ret = drv->pm->resume(dev);
802 ret = platform_legacy_resume(dev);
808 #endif /* CONFIG_SUSPEND */
810 #ifdef CONFIG_HIBERNATE_CALLBACKS
812 int platform_pm_freeze(struct device *dev)
814 struct device_driver *drv = dev->driver;
822 ret = drv->pm->freeze(dev);
824 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
830 int platform_pm_thaw(struct device *dev)
832 struct device_driver *drv = dev->driver;
840 ret = drv->pm->thaw(dev);
842 ret = platform_legacy_resume(dev);
848 int platform_pm_poweroff(struct device *dev)
850 struct device_driver *drv = dev->driver;
857 if (drv->pm->poweroff)
858 ret = drv->pm->poweroff(dev);
860 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
866 int platform_pm_restore(struct device *dev)
868 struct device_driver *drv = dev->driver;
875 if (drv->pm->restore)
876 ret = drv->pm->restore(dev);
878 ret = platform_legacy_resume(dev);
884 #endif /* CONFIG_HIBERNATE_CALLBACKS */
886 static const struct dev_pm_ops platform_dev_pm_ops = {
887 .runtime_suspend = pm_generic_runtime_suspend,
888 .runtime_resume = pm_generic_runtime_resume,
889 .runtime_idle = pm_generic_runtime_idle,
890 USE_PLATFORM_PM_SLEEP_OPS
893 struct bus_type platform_bus_type = {
895 .dev_attrs = platform_dev_attrs,
896 .match = platform_match,
897 .uevent = platform_uevent,
898 .pm = &platform_dev_pm_ops,
900 EXPORT_SYMBOL_GPL(platform_bus_type);
902 int __init platform_bus_init(void)
906 early_platform_cleanup();
908 error = device_register(&platform_bus);
911 error = bus_register(&platform_bus_type);
913 device_unregister(&platform_bus);
917 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
918 u64 dma_get_required_mask(struct device *dev)
920 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
921 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
924 if (!high_totalram) {
925 /* convert to mask just covering totalram */
926 low_totalram = (1 << (fls(low_totalram) - 1));
927 low_totalram += low_totalram - 1;
930 high_totalram = (1 << (fls(high_totalram) - 1));
931 high_totalram += high_totalram - 1;
932 mask = (((u64)high_totalram) << 32) + 0xffffffff;
936 EXPORT_SYMBOL_GPL(dma_get_required_mask);
939 static __initdata LIST_HEAD(early_platform_driver_list);
940 static __initdata LIST_HEAD(early_platform_device_list);
943 * early_platform_driver_register - register early platform driver
944 * @epdrv: early_platform driver structure
945 * @buf: string passed from early_param()
947 * Helper function for early_platform_init() / early_platform_init_buffer()
949 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
955 /* Simply add the driver to the end of the global list.
956 * Drivers will by default be put on the list in compiled-in order.
958 if (!epdrv->list.next) {
959 INIT_LIST_HEAD(&epdrv->list);
960 list_add_tail(&epdrv->list, &early_platform_driver_list);
963 /* If the user has specified device then make sure the driver
964 * gets prioritized. The driver of the last device specified on
965 * command line will be put first on the list.
967 n = strlen(epdrv->pdrv->driver.name);
968 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
969 list_move(&epdrv->list, &early_platform_driver_list);
971 /* Allow passing parameters after device name */
972 if (buf[n] == '\0' || buf[n] == ',')
973 epdrv->requested_id = -1;
975 epdrv->requested_id = simple_strtoul(&buf[n + 1],
978 if (buf[n] != '.' || (tmp == &buf[n + 1])) {
979 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
982 n += strcspn(&buf[n + 1], ",") + 1;
988 if (epdrv->bufsize) {
989 memcpy(epdrv->buffer, &buf[n],
990 min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
991 epdrv->buffer[epdrv->bufsize - 1] = '\0';
999 * early_platform_add_devices - adds a number of early platform devices
1000 * @devs: array of early platform devices to add
1001 * @num: number of early platform devices in array
1003 * Used by early architecture code to register early platform devices and
1004 * their platform data.
1006 void __init early_platform_add_devices(struct platform_device **devs, int num)
1011 /* simply add the devices to list */
1012 for (i = 0; i < num; i++) {
1013 dev = &devs[i]->dev;
1015 if (!dev->devres_head.next) {
1016 pm_runtime_early_init(dev);
1017 INIT_LIST_HEAD(&dev->devres_head);
1018 list_add_tail(&dev->devres_head,
1019 &early_platform_device_list);
1025 * early_platform_driver_register_all - register early platform drivers
1026 * @class_str: string to identify early platform driver class
1028 * Used by architecture code to register all early platform drivers
1029 * for a certain class. If omitted then only early platform drivers
1030 * with matching kernel command line class parameters will be registered.
1032 void __init early_platform_driver_register_all(char *class_str)
1034 /* The "class_str" parameter may or may not be present on the kernel
1035 * command line. If it is present then there may be more than one
1036 * matching parameter.
1038 * Since we register our early platform drivers using early_param()
1039 * we need to make sure that they also get registered in the case
1040 * when the parameter is missing from the kernel command line.
1042 * We use parse_early_options() to make sure the early_param() gets
1043 * called at least once. The early_param() may be called more than
1044 * once since the name of the preferred device may be specified on
1045 * the kernel command line. early_platform_driver_register() handles
1048 parse_early_options(class_str);
1052 * early_platform_match - find early platform device matching driver
1053 * @epdrv: early platform driver structure
1054 * @id: id to match against
1056 static __init struct platform_device *
1057 early_platform_match(struct early_platform_driver *epdrv, int id)
1059 struct platform_device *pd;
1061 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1062 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1070 * early_platform_left - check if early platform driver has matching devices
1071 * @epdrv: early platform driver structure
1072 * @id: return true if id or above exists
1074 static __init int early_platform_left(struct early_platform_driver *epdrv,
1077 struct platform_device *pd;
1079 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1080 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1088 * early_platform_driver_probe_id - probe drivers matching class_str and id
1089 * @class_str: string to identify early platform driver class
1090 * @id: id to match against
1091 * @nr_probe: number of platform devices to successfully probe before exiting
1093 static int __init early_platform_driver_probe_id(char *class_str,
1097 struct early_platform_driver *epdrv;
1098 struct platform_device *match;
1103 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1104 /* only use drivers matching our class_str */
1105 if (strcmp(class_str, epdrv->class_str))
1109 match_id = epdrv->requested_id;
1114 left += early_platform_left(epdrv, id);
1116 /* skip requested id */
1117 switch (epdrv->requested_id) {
1118 case EARLY_PLATFORM_ID_ERROR:
1119 case EARLY_PLATFORM_ID_UNSET:
1122 if (epdrv->requested_id == id)
1123 match_id = EARLY_PLATFORM_ID_UNSET;
1128 case EARLY_PLATFORM_ID_ERROR:
1129 pr_warning("%s: unable to parse %s parameter\n",
1130 class_str, epdrv->pdrv->driver.name);
1132 case EARLY_PLATFORM_ID_UNSET:
1136 match = early_platform_match(epdrv, match_id);
1141 * Set up a sensible init_name to enable
1142 * dev_name() and others to be used before the
1143 * rest of the driver core is initialized.
1145 if (!match->dev.init_name && slab_is_available()) {
1146 if (match->id != -1)
1147 match->dev.init_name =
1148 kasprintf(GFP_KERNEL, "%s.%d",
1152 match->dev.init_name =
1153 kasprintf(GFP_KERNEL, "%s",
1156 if (!match->dev.init_name)
1160 if (epdrv->pdrv->probe(match))
1161 pr_warning("%s: unable to probe %s early.\n",
1162 class_str, match->name);
1178 * early_platform_driver_probe - probe a class of registered drivers
1179 * @class_str: string to identify early platform driver class
1180 * @nr_probe: number of platform devices to successfully probe before exiting
1181 * @user_only: only probe user specified early platform devices
1183 * Used by architecture code to probe registered early platform drivers
1184 * within a certain class. For probe to happen a registered early platform
1185 * device matching a registered early platform driver is needed.
1187 int __init early_platform_driver_probe(char *class_str,
1194 for (i = -2; n < nr_probe; i++) {
1195 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1210 * early_platform_cleanup - clean up early platform code
1212 void __init early_platform_cleanup(void)
1214 struct platform_device *pd, *pd2;
1216 /* clean up the devres list used to chain devices */
1217 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1219 list_del(&pd->dev.devres_head);
1220 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));