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/of_irq.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/bootmem.h>
21 #include <linux/err.h>
22 #include <linux/slab.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/idr.h>
25 #include <linux/acpi.h>
28 #include "power/power.h"
30 /* For automatically allocated device IDs */
31 static DEFINE_IDA(platform_devid_ida);
33 struct device platform_bus = {
34 .init_name = "platform",
36 EXPORT_SYMBOL_GPL(platform_bus);
39 * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
40 * @pdev: platform device
42 * This is called before platform_device_add() such that any pdev_archdata may
43 * be setup before the platform_notifier is called. So if a user needs to
44 * manipulate any relevant information in the pdev_archdata they can do:
46 * platform_device_alloc()
48 * platform_device_add()
50 * And if they don't care they can just call platform_device_register() and
51 * everything will just work out.
53 void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
58 * platform_get_resource - get a resource for a device
59 * @dev: platform device
60 * @type: resource type
61 * @num: resource index
63 struct resource *platform_get_resource(struct platform_device *dev,
64 unsigned int type, unsigned int num)
68 for (i = 0; i < dev->num_resources; i++) {
69 struct resource *r = &dev->resource[i];
71 if (type == resource_type(r) && num-- == 0)
76 EXPORT_SYMBOL_GPL(platform_get_resource);
79 * platform_get_irq - get an IRQ for a device
80 * @dev: platform device
81 * @num: IRQ number index
83 int platform_get_irq(struct platform_device *dev, unsigned int num)
86 /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
87 if (!dev || num >= dev->archdata.num_irqs)
89 return dev->archdata.irqs[num];
92 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
95 ret = of_irq_get(dev->dev.of_node, num);
96 if (ret >= 0 || ret == -EPROBE_DEFER)
100 r = platform_get_resource(dev, IORESOURCE_IRQ, num);
102 return r ? r->start : -ENXIO;
105 EXPORT_SYMBOL_GPL(platform_get_irq);
108 * platform_get_resource_byname - get a resource for a device by name
109 * @dev: platform device
110 * @type: resource type
111 * @name: resource name
113 struct resource *platform_get_resource_byname(struct platform_device *dev,
119 for (i = 0; i < dev->num_resources; i++) {
120 struct resource *r = &dev->resource[i];
122 if (unlikely(!r->name))
125 if (type == resource_type(r) && !strcmp(r->name, name))
130 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
133 * platform_get_irq_byname - get an IRQ for a device by name
134 * @dev: platform device
137 int platform_get_irq_byname(struct platform_device *dev, const char *name)
141 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
144 ret = of_irq_get_byname(dev->dev.of_node, name);
145 if (ret >= 0 || ret == -EPROBE_DEFER)
149 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
150 return r ? r->start : -ENXIO;
152 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
155 * platform_add_devices - add a numbers of platform devices
156 * @devs: array of platform devices to add
157 * @num: number of platform devices in array
159 int platform_add_devices(struct platform_device **devs, int num)
163 for (i = 0; i < num; i++) {
164 ret = platform_device_register(devs[i]);
167 platform_device_unregister(devs[i]);
174 EXPORT_SYMBOL_GPL(platform_add_devices);
176 struct platform_object {
177 struct platform_device pdev;
182 * platform_device_put - destroy a platform device
183 * @pdev: platform device to free
185 * Free all memory associated with a platform device. This function must
186 * _only_ be externally called in error cases. All other usage is a bug.
188 void platform_device_put(struct platform_device *pdev)
191 put_device(&pdev->dev);
193 EXPORT_SYMBOL_GPL(platform_device_put);
195 static void platform_device_release(struct device *dev)
197 struct platform_object *pa = container_of(dev, struct platform_object,
200 of_device_node_put(&pa->pdev.dev);
201 kfree(pa->pdev.dev.platform_data);
202 kfree(pa->pdev.mfd_cell);
203 kfree(pa->pdev.resource);
208 * platform_device_alloc - create a platform device
209 * @name: base name of the device we're adding
212 * Create a platform device object which can have other objects attached
213 * to it, and which will have attached objects freed when it is released.
215 struct platform_device *platform_device_alloc(const char *name, int id)
217 struct platform_object *pa;
219 pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
221 strcpy(pa->name, name);
222 pa->pdev.name = pa->name;
224 device_initialize(&pa->pdev.dev);
225 pa->pdev.dev.release = platform_device_release;
226 arch_setup_pdev_archdata(&pa->pdev);
229 return pa ? &pa->pdev : NULL;
231 EXPORT_SYMBOL_GPL(platform_device_alloc);
234 * platform_device_add_resources - add resources to a platform device
235 * @pdev: platform device allocated by platform_device_alloc to add resources to
236 * @res: set of resources that needs to be allocated for the device
237 * @num: number of resources
239 * Add a copy of the resources to the platform device. The memory
240 * associated with the resources will be freed when the platform device is
243 int platform_device_add_resources(struct platform_device *pdev,
244 const struct resource *res, unsigned int num)
246 struct resource *r = NULL;
249 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
254 kfree(pdev->resource);
256 pdev->num_resources = num;
259 EXPORT_SYMBOL_GPL(platform_device_add_resources);
262 * platform_device_add_data - add platform-specific data to a platform device
263 * @pdev: platform device allocated by platform_device_alloc to add resources to
264 * @data: platform specific data for this platform device
265 * @size: size of platform specific data
267 * Add a copy of platform specific data to the platform device's
268 * platform_data pointer. The memory associated with the platform data
269 * will be freed when the platform device is released.
271 int platform_device_add_data(struct platform_device *pdev, const void *data,
277 d = kmemdup(data, size, GFP_KERNEL);
282 kfree(pdev->dev.platform_data);
283 pdev->dev.platform_data = d;
286 EXPORT_SYMBOL_GPL(platform_device_add_data);
289 * platform_device_add - add a platform device to device hierarchy
290 * @pdev: platform device we're adding
292 * This is part 2 of platform_device_register(), though may be called
293 * separately _iff_ pdev was allocated by platform_device_alloc().
295 int platform_device_add(struct platform_device *pdev)
302 if (!pdev->dev.parent)
303 pdev->dev.parent = &platform_bus;
305 pdev->dev.bus = &platform_bus_type;
309 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
311 case PLATFORM_DEVID_NONE:
312 dev_set_name(&pdev->dev, "%s", pdev->name);
314 case PLATFORM_DEVID_AUTO:
316 * Automatically allocated device ID. We mark it as such so
317 * that we remember it must be freed, and we append a suffix
318 * to avoid namespace collision with explicit IDs.
320 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
324 pdev->id_auto = true;
325 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
329 for (i = 0; i < pdev->num_resources; i++) {
330 struct resource *p, *r = &pdev->resource[i];
333 r->name = dev_name(&pdev->dev);
337 if (resource_type(r) == IORESOURCE_MEM)
339 else if (resource_type(r) == IORESOURCE_IO)
340 p = &ioport_resource;
343 if (p && insert_resource(p, r)) {
344 dev_err(&pdev->dev, "failed to claim resource %d\n", i);
350 pr_debug("Registering platform device '%s'. Parent at %s\n",
351 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
353 ret = device_add(&pdev->dev);
359 ida_simple_remove(&platform_devid_ida, pdev->id);
360 pdev->id = PLATFORM_DEVID_AUTO;
364 struct resource *r = &pdev->resource[i];
365 unsigned long type = resource_type(r);
367 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
374 EXPORT_SYMBOL_GPL(platform_device_add);
377 * platform_device_del - remove a platform-level device
378 * @pdev: platform device we're removing
380 * Note that this function will also release all memory- and port-based
381 * resources owned by the device (@dev->resource). This function must
382 * _only_ be externally called in error cases. All other usage is a bug.
384 void platform_device_del(struct platform_device *pdev)
389 device_del(&pdev->dev);
392 ida_simple_remove(&platform_devid_ida, pdev->id);
393 pdev->id = PLATFORM_DEVID_AUTO;
396 for (i = 0; i < pdev->num_resources; i++) {
397 struct resource *r = &pdev->resource[i];
398 unsigned long type = resource_type(r);
400 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
405 EXPORT_SYMBOL_GPL(platform_device_del);
408 * platform_device_register - add a platform-level device
409 * @pdev: platform device we're adding
411 int platform_device_register(struct platform_device *pdev)
413 device_initialize(&pdev->dev);
414 arch_setup_pdev_archdata(pdev);
415 return platform_device_add(pdev);
417 EXPORT_SYMBOL_GPL(platform_device_register);
420 * platform_device_unregister - unregister a platform-level device
421 * @pdev: platform device we're unregistering
423 * Unregistration is done in 2 steps. First we release all resources
424 * and remove it from the subsystem, then we drop reference count by
425 * calling platform_device_put().
427 void platform_device_unregister(struct platform_device *pdev)
429 platform_device_del(pdev);
430 platform_device_put(pdev);
432 EXPORT_SYMBOL_GPL(platform_device_unregister);
435 * platform_device_register_full - add a platform-level device with
436 * resources and platform-specific data
438 * @pdevinfo: data used to create device
440 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
442 struct platform_device *platform_device_register_full(
443 const struct platform_device_info *pdevinfo)
446 struct platform_device *pdev;
448 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
452 pdev->dev.parent = pdevinfo->parent;
453 ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion);
455 if (pdevinfo->dma_mask) {
457 * This memory isn't freed when the device is put,
458 * I don't have a nice idea for that though. Conceptually
459 * dma_mask in struct device should not be a pointer.
460 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
463 kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
464 if (!pdev->dev.dma_mask)
467 *pdev->dev.dma_mask = pdevinfo->dma_mask;
468 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
471 ret = platform_device_add_resources(pdev,
472 pdevinfo->res, pdevinfo->num_res);
476 ret = platform_device_add_data(pdev,
477 pdevinfo->data, pdevinfo->size_data);
481 ret = platform_device_add(pdev);
484 ACPI_COMPANION_SET(&pdev->dev, NULL);
485 kfree(pdev->dev.dma_mask);
488 platform_device_put(pdev);
494 EXPORT_SYMBOL_GPL(platform_device_register_full);
496 static int platform_drv_probe(struct device *_dev)
498 struct platform_driver *drv = to_platform_driver(_dev->driver);
499 struct platform_device *dev = to_platform_device(_dev);
502 acpi_dev_pm_attach(_dev, true);
504 ret = drv->probe(dev);
506 acpi_dev_pm_detach(_dev, true);
508 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
509 dev_warn(_dev, "probe deferral not supported\n");
516 static int platform_drv_probe_fail(struct device *_dev)
521 static int platform_drv_remove(struct device *_dev)
523 struct platform_driver *drv = to_platform_driver(_dev->driver);
524 struct platform_device *dev = to_platform_device(_dev);
527 ret = drv->remove(dev);
528 acpi_dev_pm_detach(_dev, true);
533 static void platform_drv_shutdown(struct device *_dev)
535 struct platform_driver *drv = to_platform_driver(_dev->driver);
536 struct platform_device *dev = to_platform_device(_dev);
539 acpi_dev_pm_detach(_dev, true);
543 * __platform_driver_register - register a driver for platform-level devices
544 * @drv: platform driver structure
545 * @owner: owning module/driver
547 int __platform_driver_register(struct platform_driver *drv,
548 struct module *owner)
550 drv->driver.owner = owner;
551 drv->driver.bus = &platform_bus_type;
553 drv->driver.probe = platform_drv_probe;
555 drv->driver.remove = platform_drv_remove;
557 drv->driver.shutdown = platform_drv_shutdown;
559 return driver_register(&drv->driver);
561 EXPORT_SYMBOL_GPL(__platform_driver_register);
564 * platform_driver_unregister - unregister a driver for platform-level devices
565 * @drv: platform driver structure
567 void platform_driver_unregister(struct platform_driver *drv)
569 driver_unregister(&drv->driver);
571 EXPORT_SYMBOL_GPL(platform_driver_unregister);
574 * platform_driver_probe - register driver for non-hotpluggable device
575 * @drv: platform driver structure
576 * @probe: the driver probe routine, probably from an __init section
578 * Use this instead of platform_driver_register() when you know the device
579 * is not hotpluggable and has already been registered, and you want to
580 * remove its run-once probe() infrastructure from memory after the driver
581 * has bound to the device.
583 * One typical use for this would be with drivers for controllers integrated
584 * into system-on-chip processors, where the controller devices have been
585 * configured as part of board setup.
587 * Note that this is incompatible with deferred probing.
589 * Returns zero if the driver registered and bound to a device, else returns
590 * a negative error code and with the driver not registered.
592 int __init_or_module platform_driver_probe(struct platform_driver *drv,
593 int (*probe)(struct platform_device *))
598 * Prevent driver from requesting probe deferral to avoid further
599 * futile probe attempts.
601 drv->prevent_deferred_probe = true;
603 /* make sure driver won't have bind/unbind attributes */
604 drv->driver.suppress_bind_attrs = true;
606 /* temporary section violation during probe() */
608 retval = code = platform_driver_register(drv);
611 * Fixup that section violation, being paranoid about code scanning
612 * the list of drivers in order to probe new devices. Check to see
613 * if the probe was successful, and make sure any forced probes of
616 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
618 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
620 drv->driver.probe = platform_drv_probe_fail;
621 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
624 platform_driver_unregister(drv);
627 EXPORT_SYMBOL_GPL(platform_driver_probe);
630 * platform_create_bundle - register driver and create corresponding device
631 * @driver: platform driver structure
632 * @probe: the driver probe routine, probably from an __init section
633 * @res: set of resources that needs to be allocated for the device
634 * @n_res: number of resources
635 * @data: platform specific data for this platform device
636 * @size: size of platform specific data
638 * Use this in legacy-style modules that probe hardware directly and
639 * register a single platform device and corresponding platform driver.
641 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
643 struct platform_device * __init_or_module platform_create_bundle(
644 struct platform_driver *driver,
645 int (*probe)(struct platform_device *),
646 struct resource *res, unsigned int n_res,
647 const void *data, size_t size)
649 struct platform_device *pdev;
652 pdev = platform_device_alloc(driver->driver.name, -1);
658 error = platform_device_add_resources(pdev, res, n_res);
662 error = platform_device_add_data(pdev, data, size);
666 error = platform_device_add(pdev);
670 error = platform_driver_probe(driver, probe);
677 platform_device_del(pdev);
679 platform_device_put(pdev);
681 return ERR_PTR(error);
683 EXPORT_SYMBOL_GPL(platform_create_bundle);
685 /* modalias support enables more hands-off userspace setup:
686 * (a) environment variable lets new-style hotplug events work once system is
687 * fully running: "modprobe $MODALIAS"
688 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
689 * mishandled before system is fully running: "modprobe $(cat modalias)"
691 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
694 struct platform_device *pdev = to_platform_device(dev);
697 len = of_device_get_modalias(dev, buf, PAGE_SIZE -1);
701 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
705 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
707 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
709 static DEVICE_ATTR_RO(modalias);
711 static struct attribute *platform_dev_attrs[] = {
712 &dev_attr_modalias.attr,
715 ATTRIBUTE_GROUPS(platform_dev);
717 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
719 struct platform_device *pdev = to_platform_device(dev);
722 /* Some devices have extra OF data and an OF-style MODALIAS */
723 rc = of_device_uevent_modalias(dev, env);
727 rc = acpi_device_uevent_modalias(dev, env);
731 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
736 static const struct platform_device_id *platform_match_id(
737 const struct platform_device_id *id,
738 struct platform_device *pdev)
740 while (id->name[0]) {
741 if (strcmp(pdev->name, id->name) == 0) {
751 * platform_match - bind platform device to platform driver.
755 * Platform device IDs are assumed to be encoded like this:
756 * "<name><instance>", where <name> is a short description of the type of
757 * device, like "pci" or "floppy", and <instance> is the enumerated
758 * instance of the device, like '0' or '42'. Driver IDs are simply
759 * "<name>". So, extract the <name> from the platform_device structure,
760 * and compare it against the name of the driver. Return whether they match
763 static int platform_match(struct device *dev, struct device_driver *drv)
765 struct platform_device *pdev = to_platform_device(dev);
766 struct platform_driver *pdrv = to_platform_driver(drv);
768 /* Attempt an OF style match first */
769 if (of_driver_match_device(dev, drv))
772 /* Then try ACPI style match */
773 if (acpi_driver_match_device(dev, drv))
776 /* Then try to match against the id table */
778 return platform_match_id(pdrv->id_table, pdev) != NULL;
780 /* fall-back to driver name match */
781 return (strcmp(pdev->name, drv->name) == 0);
784 #ifdef CONFIG_PM_SLEEP
786 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
788 struct platform_driver *pdrv = to_platform_driver(dev->driver);
789 struct platform_device *pdev = to_platform_device(dev);
792 if (dev->driver && pdrv->suspend)
793 ret = pdrv->suspend(pdev, mesg);
798 static int platform_legacy_resume(struct device *dev)
800 struct platform_driver *pdrv = to_platform_driver(dev->driver);
801 struct platform_device *pdev = to_platform_device(dev);
804 if (dev->driver && pdrv->resume)
805 ret = pdrv->resume(pdev);
810 #endif /* CONFIG_PM_SLEEP */
812 #ifdef CONFIG_SUSPEND
814 int platform_pm_suspend(struct device *dev)
816 struct device_driver *drv = dev->driver;
823 if (drv->pm->suspend)
824 ret = drv->pm->suspend(dev);
826 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
832 int platform_pm_resume(struct device *dev)
834 struct device_driver *drv = dev->driver;
842 ret = drv->pm->resume(dev);
844 ret = platform_legacy_resume(dev);
850 #endif /* CONFIG_SUSPEND */
852 #ifdef CONFIG_HIBERNATE_CALLBACKS
854 int platform_pm_freeze(struct device *dev)
856 struct device_driver *drv = dev->driver;
864 ret = drv->pm->freeze(dev);
866 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
872 int platform_pm_thaw(struct device *dev)
874 struct device_driver *drv = dev->driver;
882 ret = drv->pm->thaw(dev);
884 ret = platform_legacy_resume(dev);
890 int platform_pm_poweroff(struct device *dev)
892 struct device_driver *drv = dev->driver;
899 if (drv->pm->poweroff)
900 ret = drv->pm->poweroff(dev);
902 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
908 int platform_pm_restore(struct device *dev)
910 struct device_driver *drv = dev->driver;
917 if (drv->pm->restore)
918 ret = drv->pm->restore(dev);
920 ret = platform_legacy_resume(dev);
926 #endif /* CONFIG_HIBERNATE_CALLBACKS */
928 static const struct dev_pm_ops platform_dev_pm_ops = {
929 .runtime_suspend = pm_generic_runtime_suspend,
930 .runtime_resume = pm_generic_runtime_resume,
931 USE_PLATFORM_PM_SLEEP_OPS
934 struct bus_type platform_bus_type = {
936 .dev_groups = platform_dev_groups,
937 .match = platform_match,
938 .uevent = platform_uevent,
939 .pm = &platform_dev_pm_ops,
941 EXPORT_SYMBOL_GPL(platform_bus_type);
943 int __init platform_bus_init(void)
947 early_platform_cleanup();
949 error = device_register(&platform_bus);
952 error = bus_register(&platform_bus_type);
954 device_unregister(&platform_bus);
958 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
959 u64 dma_get_required_mask(struct device *dev)
961 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
962 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
965 if (!high_totalram) {
966 /* convert to mask just covering totalram */
967 low_totalram = (1 << (fls(low_totalram) - 1));
968 low_totalram += low_totalram - 1;
971 high_totalram = (1 << (fls(high_totalram) - 1));
972 high_totalram += high_totalram - 1;
973 mask = (((u64)high_totalram) << 32) + 0xffffffff;
977 EXPORT_SYMBOL_GPL(dma_get_required_mask);
980 static __initdata LIST_HEAD(early_platform_driver_list);
981 static __initdata LIST_HEAD(early_platform_device_list);
984 * early_platform_driver_register - register early platform driver
985 * @epdrv: early_platform driver structure
986 * @buf: string passed from early_param()
988 * Helper function for early_platform_init() / early_platform_init_buffer()
990 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
996 /* Simply add the driver to the end of the global list.
997 * Drivers will by default be put on the list in compiled-in order.
999 if (!epdrv->list.next) {
1000 INIT_LIST_HEAD(&epdrv->list);
1001 list_add_tail(&epdrv->list, &early_platform_driver_list);
1004 /* If the user has specified device then make sure the driver
1005 * gets prioritized. The driver of the last device specified on
1006 * command line will be put first on the list.
1008 n = strlen(epdrv->pdrv->driver.name);
1009 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1010 list_move(&epdrv->list, &early_platform_driver_list);
1012 /* Allow passing parameters after device name */
1013 if (buf[n] == '\0' || buf[n] == ',')
1014 epdrv->requested_id = -1;
1016 epdrv->requested_id = simple_strtoul(&buf[n + 1],
1019 if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1020 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1023 n += strcspn(&buf[n + 1], ",") + 1;
1029 if (epdrv->bufsize) {
1030 memcpy(epdrv->buffer, &buf[n],
1031 min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1032 epdrv->buffer[epdrv->bufsize - 1] = '\0';
1040 * early_platform_add_devices - adds a number of early platform devices
1041 * @devs: array of early platform devices to add
1042 * @num: number of early platform devices in array
1044 * Used by early architecture code to register early platform devices and
1045 * their platform data.
1047 void __init early_platform_add_devices(struct platform_device **devs, int num)
1052 /* simply add the devices to list */
1053 for (i = 0; i < num; i++) {
1054 dev = &devs[i]->dev;
1056 if (!dev->devres_head.next) {
1057 pm_runtime_early_init(dev);
1058 INIT_LIST_HEAD(&dev->devres_head);
1059 list_add_tail(&dev->devres_head,
1060 &early_platform_device_list);
1066 * early_platform_driver_register_all - register early platform drivers
1067 * @class_str: string to identify early platform driver class
1069 * Used by architecture code to register all early platform drivers
1070 * for a certain class. If omitted then only early platform drivers
1071 * with matching kernel command line class parameters will be registered.
1073 void __init early_platform_driver_register_all(char *class_str)
1075 /* The "class_str" parameter may or may not be present on the kernel
1076 * command line. If it is present then there may be more than one
1077 * matching parameter.
1079 * Since we register our early platform drivers using early_param()
1080 * we need to make sure that they also get registered in the case
1081 * when the parameter is missing from the kernel command line.
1083 * We use parse_early_options() to make sure the early_param() gets
1084 * called at least once. The early_param() may be called more than
1085 * once since the name of the preferred device may be specified on
1086 * the kernel command line. early_platform_driver_register() handles
1089 parse_early_options(class_str);
1093 * early_platform_match - find early platform device matching driver
1094 * @epdrv: early platform driver structure
1095 * @id: id to match against
1097 static struct platform_device * __init
1098 early_platform_match(struct early_platform_driver *epdrv, int id)
1100 struct platform_device *pd;
1102 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1103 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1111 * early_platform_left - check if early platform driver has matching devices
1112 * @epdrv: early platform driver structure
1113 * @id: return true if id or above exists
1115 static int __init early_platform_left(struct early_platform_driver *epdrv,
1118 struct platform_device *pd;
1120 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1121 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1129 * early_platform_driver_probe_id - probe drivers matching class_str and id
1130 * @class_str: string to identify early platform driver class
1131 * @id: id to match against
1132 * @nr_probe: number of platform devices to successfully probe before exiting
1134 static int __init early_platform_driver_probe_id(char *class_str,
1138 struct early_platform_driver *epdrv;
1139 struct platform_device *match;
1144 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1145 /* only use drivers matching our class_str */
1146 if (strcmp(class_str, epdrv->class_str))
1150 match_id = epdrv->requested_id;
1155 left += early_platform_left(epdrv, id);
1157 /* skip requested id */
1158 switch (epdrv->requested_id) {
1159 case EARLY_PLATFORM_ID_ERROR:
1160 case EARLY_PLATFORM_ID_UNSET:
1163 if (epdrv->requested_id == id)
1164 match_id = EARLY_PLATFORM_ID_UNSET;
1169 case EARLY_PLATFORM_ID_ERROR:
1170 pr_warn("%s: unable to parse %s parameter\n",
1171 class_str, epdrv->pdrv->driver.name);
1173 case EARLY_PLATFORM_ID_UNSET:
1177 match = early_platform_match(epdrv, match_id);
1182 * Set up a sensible init_name to enable
1183 * dev_name() and others to be used before the
1184 * rest of the driver core is initialized.
1186 if (!match->dev.init_name && slab_is_available()) {
1187 if (match->id != -1)
1188 match->dev.init_name =
1189 kasprintf(GFP_KERNEL, "%s.%d",
1193 match->dev.init_name =
1194 kasprintf(GFP_KERNEL, "%s",
1197 if (!match->dev.init_name)
1201 if (epdrv->pdrv->probe(match))
1202 pr_warn("%s: unable to probe %s early.\n",
1203 class_str, match->name);
1219 * early_platform_driver_probe - probe a class of registered drivers
1220 * @class_str: string to identify early platform driver class
1221 * @nr_probe: number of platform devices to successfully probe before exiting
1222 * @user_only: only probe user specified early platform devices
1224 * Used by architecture code to probe registered early platform drivers
1225 * within a certain class. For probe to happen a registered early platform
1226 * device matching a registered early platform driver is needed.
1228 int __init early_platform_driver_probe(char *class_str,
1235 for (i = -2; n < nr_probe; i++) {
1236 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1251 * early_platform_cleanup - clean up early platform code
1253 void __init early_platform_cleanup(void)
1255 struct platform_device *pd, *pd2;
1257 /* clean up the devres list used to chain devices */
1258 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1260 list_del(&pd->dev.devres_head);
1261 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));