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>
26 #include <linux/clk/clk-conf.h>
27 #include <linux/limits.h>
30 #include "power/power.h"
32 /* For automatically allocated device IDs */
33 static DEFINE_IDA(platform_devid_ida);
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];
94 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
97 ret = of_irq_get(dev->dev.of_node, num);
98 if (ret >= 0 || ret == -EPROBE_DEFER)
102 r = platform_get_resource(dev, IORESOURCE_IRQ, num);
104 return r ? r->start : -ENXIO;
107 EXPORT_SYMBOL_GPL(platform_get_irq);
110 * platform_get_resource_byname - get a resource for a device by name
111 * @dev: platform device
112 * @type: resource type
113 * @name: resource name
115 struct resource *platform_get_resource_byname(struct platform_device *dev,
121 for (i = 0; i < dev->num_resources; i++) {
122 struct resource *r = &dev->resource[i];
124 if (unlikely(!r->name))
127 if (type == resource_type(r) && !strcmp(r->name, name))
132 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
135 * platform_get_irq_byname - get an IRQ for a device by name
136 * @dev: platform device
139 int platform_get_irq_byname(struct platform_device *dev, const char *name)
143 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
146 ret = of_irq_get_byname(dev->dev.of_node, name);
147 if (ret >= 0 || ret == -EPROBE_DEFER)
151 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
152 return r ? r->start : -ENXIO;
154 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
157 * platform_add_devices - add a numbers of platform devices
158 * @devs: array of platform devices to add
159 * @num: number of platform devices in array
161 int platform_add_devices(struct platform_device **devs, int num)
165 for (i = 0; i < num; i++) {
166 ret = platform_device_register(devs[i]);
169 platform_device_unregister(devs[i]);
176 EXPORT_SYMBOL_GPL(platform_add_devices);
178 struct platform_object {
179 struct platform_device pdev;
184 * platform_device_put - destroy a platform device
185 * @pdev: platform device to free
187 * Free all memory associated with a platform device. This function must
188 * _only_ be externally called in error cases. All other usage is a bug.
190 void platform_device_put(struct platform_device *pdev)
193 put_device(&pdev->dev);
195 EXPORT_SYMBOL_GPL(platform_device_put);
197 static void platform_device_release(struct device *dev)
199 struct platform_object *pa = container_of(dev, struct platform_object,
202 of_device_node_put(&pa->pdev.dev);
203 kfree(pa->pdev.dev.platform_data);
204 kfree(pa->pdev.mfd_cell);
205 kfree(pa->pdev.resource);
206 kfree(pa->pdev.driver_override);
211 * platform_device_alloc - create a platform device
212 * @name: base name of the device we're adding
215 * Create a platform device object which can have other objects attached
216 * to it, and which will have attached objects freed when it is released.
218 struct platform_device *platform_device_alloc(const char *name, int id)
220 struct platform_object *pa;
222 pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
224 strcpy(pa->name, name);
225 pa->pdev.name = pa->name;
227 device_initialize(&pa->pdev.dev);
228 pa->pdev.dev.release = platform_device_release;
229 arch_setup_pdev_archdata(&pa->pdev);
232 return pa ? &pa->pdev : NULL;
234 EXPORT_SYMBOL_GPL(platform_device_alloc);
237 * platform_device_add_resources - add resources to a platform device
238 * @pdev: platform device allocated by platform_device_alloc to add resources to
239 * @res: set of resources that needs to be allocated for the device
240 * @num: number of resources
242 * Add a copy of the resources to the platform device. The memory
243 * associated with the resources will be freed when the platform device is
246 int platform_device_add_resources(struct platform_device *pdev,
247 const struct resource *res, unsigned int num)
249 struct resource *r = NULL;
252 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
257 kfree(pdev->resource);
259 pdev->num_resources = num;
262 EXPORT_SYMBOL_GPL(platform_device_add_resources);
265 * platform_device_add_data - add platform-specific data to a platform device
266 * @pdev: platform device allocated by platform_device_alloc to add resources to
267 * @data: platform specific data for this platform device
268 * @size: size of platform specific data
270 * Add a copy of platform specific data to the platform device's
271 * platform_data pointer. The memory associated with the platform data
272 * will be freed when the platform device is released.
274 int platform_device_add_data(struct platform_device *pdev, const void *data,
280 d = kmemdup(data, size, GFP_KERNEL);
285 kfree(pdev->dev.platform_data);
286 pdev->dev.platform_data = d;
289 EXPORT_SYMBOL_GPL(platform_device_add_data);
292 * platform_device_add - add a platform device to device hierarchy
293 * @pdev: platform device we're adding
295 * This is part 2 of platform_device_register(), though may be called
296 * separately _iff_ pdev was allocated by platform_device_alloc().
298 int platform_device_add(struct platform_device *pdev)
305 if (!pdev->dev.parent)
306 pdev->dev.parent = &platform_bus;
308 pdev->dev.bus = &platform_bus_type;
312 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
314 case PLATFORM_DEVID_NONE:
315 dev_set_name(&pdev->dev, "%s", pdev->name);
317 case PLATFORM_DEVID_AUTO:
319 * Automatically allocated device ID. We mark it as such so
320 * that we remember it must be freed, and we append a suffix
321 * to avoid namespace collision with explicit IDs.
323 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
327 pdev->id_auto = true;
328 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
332 for (i = 0; i < pdev->num_resources; i++) {
333 struct resource *p, *r = &pdev->resource[i];
336 r->name = dev_name(&pdev->dev);
340 if (resource_type(r) == IORESOURCE_MEM)
342 else if (resource_type(r) == IORESOURCE_IO)
343 p = &ioport_resource;
346 if (p && insert_resource(p, r)) {
347 dev_err(&pdev->dev, "failed to claim resource %d\n", i);
353 pr_debug("Registering platform device '%s'. Parent at %s\n",
354 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
356 ret = device_add(&pdev->dev);
362 ida_simple_remove(&platform_devid_ida, pdev->id);
363 pdev->id = PLATFORM_DEVID_AUTO;
367 struct resource *r = &pdev->resource[i];
368 unsigned long type = resource_type(r);
370 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
377 EXPORT_SYMBOL_GPL(platform_device_add);
380 * platform_device_del - remove a platform-level device
381 * @pdev: platform device we're removing
383 * Note that this function will also release all memory- and port-based
384 * resources owned by the device (@dev->resource). This function must
385 * _only_ be externally called in error cases. All other usage is a bug.
387 void platform_device_del(struct platform_device *pdev)
392 device_del(&pdev->dev);
395 ida_simple_remove(&platform_devid_ida, pdev->id);
396 pdev->id = PLATFORM_DEVID_AUTO;
399 for (i = 0; i < pdev->num_resources; i++) {
400 struct resource *r = &pdev->resource[i];
401 unsigned long type = resource_type(r);
403 if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
408 EXPORT_SYMBOL_GPL(platform_device_del);
411 * platform_device_register - add a platform-level device
412 * @pdev: platform device we're adding
414 int platform_device_register(struct platform_device *pdev)
416 device_initialize(&pdev->dev);
417 arch_setup_pdev_archdata(pdev);
418 return platform_device_add(pdev);
420 EXPORT_SYMBOL_GPL(platform_device_register);
423 * platform_device_unregister - unregister a platform-level device
424 * @pdev: platform device we're unregistering
426 * Unregistration is done in 2 steps. First we release all resources
427 * and remove it from the subsystem, then we drop reference count by
428 * calling platform_device_put().
430 void platform_device_unregister(struct platform_device *pdev)
432 platform_device_del(pdev);
433 platform_device_put(pdev);
435 EXPORT_SYMBOL_GPL(platform_device_unregister);
438 * platform_device_register_full - add a platform-level device with
439 * resources and platform-specific data
441 * @pdevinfo: data used to create device
443 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
445 struct platform_device *platform_device_register_full(
446 const struct platform_device_info *pdevinfo)
449 struct platform_device *pdev;
451 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
455 pdev->dev.parent = pdevinfo->parent;
456 ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion);
458 if (pdevinfo->dma_mask) {
460 * This memory isn't freed when the device is put,
461 * I don't have a nice idea for that though. Conceptually
462 * dma_mask in struct device should not be a pointer.
463 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
466 kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
467 if (!pdev->dev.dma_mask)
470 *pdev->dev.dma_mask = pdevinfo->dma_mask;
471 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
474 ret = platform_device_add_resources(pdev,
475 pdevinfo->res, pdevinfo->num_res);
479 ret = platform_device_add_data(pdev,
480 pdevinfo->data, pdevinfo->size_data);
484 ret = platform_device_add(pdev);
487 ACPI_COMPANION_SET(&pdev->dev, NULL);
488 kfree(pdev->dev.dma_mask);
491 platform_device_put(pdev);
497 EXPORT_SYMBOL_GPL(platform_device_register_full);
499 static int platform_drv_probe(struct device *_dev)
501 struct platform_driver *drv = to_platform_driver(_dev->driver);
502 struct platform_device *dev = to_platform_device(_dev);
505 ret = of_clk_set_defaults(_dev->of_node, false);
509 acpi_dev_pm_attach(_dev, true);
511 ret = drv->probe(dev);
513 acpi_dev_pm_detach(_dev, true);
515 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
516 dev_warn(_dev, "probe deferral not supported\n");
523 static int platform_drv_probe_fail(struct device *_dev)
528 static int platform_drv_remove(struct device *_dev)
530 struct platform_driver *drv = to_platform_driver(_dev->driver);
531 struct platform_device *dev = to_platform_device(_dev);
534 ret = drv->remove(dev);
535 acpi_dev_pm_detach(_dev, true);
540 static void platform_drv_shutdown(struct device *_dev)
542 struct platform_driver *drv = to_platform_driver(_dev->driver);
543 struct platform_device *dev = to_platform_device(_dev);
546 acpi_dev_pm_detach(_dev, true);
550 * __platform_driver_register - register a driver for platform-level devices
551 * @drv: platform driver structure
552 * @owner: owning module/driver
554 int __platform_driver_register(struct platform_driver *drv,
555 struct module *owner)
557 drv->driver.owner = owner;
558 drv->driver.bus = &platform_bus_type;
560 drv->driver.probe = platform_drv_probe;
562 drv->driver.remove = platform_drv_remove;
564 drv->driver.shutdown = platform_drv_shutdown;
566 return driver_register(&drv->driver);
568 EXPORT_SYMBOL_GPL(__platform_driver_register);
571 * platform_driver_unregister - unregister a driver for platform-level devices
572 * @drv: platform driver structure
574 void platform_driver_unregister(struct platform_driver *drv)
576 driver_unregister(&drv->driver);
578 EXPORT_SYMBOL_GPL(platform_driver_unregister);
581 * platform_driver_probe - register driver for non-hotpluggable device
582 * @drv: platform driver structure
583 * @probe: the driver probe routine, probably from an __init section
585 * Use this instead of platform_driver_register() when you know the device
586 * is not hotpluggable and has already been registered, and you want to
587 * remove its run-once probe() infrastructure from memory after the driver
588 * has bound to the device.
590 * One typical use for this would be with drivers for controllers integrated
591 * into system-on-chip processors, where the controller devices have been
592 * configured as part of board setup.
594 * Note that this is incompatible with deferred probing.
596 * Returns zero if the driver registered and bound to a device, else returns
597 * a negative error code and with the driver not registered.
599 int __init_or_module platform_driver_probe(struct platform_driver *drv,
600 int (*probe)(struct platform_device *))
605 * Prevent driver from requesting probe deferral to avoid further
606 * futile probe attempts.
608 drv->prevent_deferred_probe = true;
610 /* make sure driver won't have bind/unbind attributes */
611 drv->driver.suppress_bind_attrs = true;
613 /* temporary section violation during probe() */
615 retval = code = platform_driver_register(drv);
618 * Fixup that section violation, being paranoid about code scanning
619 * the list of drivers in order to probe new devices. Check to see
620 * if the probe was successful, and make sure any forced probes of
623 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
625 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
627 drv->driver.probe = platform_drv_probe_fail;
628 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
631 platform_driver_unregister(drv);
634 EXPORT_SYMBOL_GPL(platform_driver_probe);
637 * platform_create_bundle - register driver and create corresponding device
638 * @driver: platform driver structure
639 * @probe: the driver probe routine, probably from an __init section
640 * @res: set of resources that needs to be allocated for the device
641 * @n_res: number of resources
642 * @data: platform specific data for this platform device
643 * @size: size of platform specific data
645 * Use this in legacy-style modules that probe hardware directly and
646 * register a single platform device and corresponding platform driver.
648 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
650 struct platform_device * __init_or_module platform_create_bundle(
651 struct platform_driver *driver,
652 int (*probe)(struct platform_device *),
653 struct resource *res, unsigned int n_res,
654 const void *data, size_t size)
656 struct platform_device *pdev;
659 pdev = platform_device_alloc(driver->driver.name, -1);
665 error = platform_device_add_resources(pdev, res, n_res);
669 error = platform_device_add_data(pdev, data, size);
673 error = platform_device_add(pdev);
677 error = platform_driver_probe(driver, probe);
684 platform_device_del(pdev);
686 platform_device_put(pdev);
688 return ERR_PTR(error);
690 EXPORT_SYMBOL_GPL(platform_create_bundle);
692 /* modalias support enables more hands-off userspace setup:
693 * (a) environment variable lets new-style hotplug events work once system is
694 * fully running: "modprobe $MODALIAS"
695 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
696 * mishandled before system is fully running: "modprobe $(cat modalias)"
698 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
701 struct platform_device *pdev = to_platform_device(dev);
704 len = of_device_get_modalias(dev, buf, PAGE_SIZE -1);
708 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
712 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
714 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
716 static DEVICE_ATTR_RO(modalias);
718 static ssize_t driver_override_store(struct device *dev,
719 struct device_attribute *attr,
720 const char *buf, size_t count)
722 struct platform_device *pdev = to_platform_device(dev);
723 char *driver_override, *old = pdev->driver_override, *cp;
725 if (count > PATH_MAX)
728 driver_override = kstrndup(buf, count, GFP_KERNEL);
729 if (!driver_override)
732 cp = strchr(driver_override, '\n');
736 if (strlen(driver_override)) {
737 pdev->driver_override = driver_override;
739 kfree(driver_override);
740 pdev->driver_override = NULL;
748 static ssize_t driver_override_show(struct device *dev,
749 struct device_attribute *attr, char *buf)
751 struct platform_device *pdev = to_platform_device(dev);
753 return sprintf(buf, "%s\n", pdev->driver_override);
755 static DEVICE_ATTR_RW(driver_override);
758 static struct attribute *platform_dev_attrs[] = {
759 &dev_attr_modalias.attr,
760 &dev_attr_driver_override.attr,
763 ATTRIBUTE_GROUPS(platform_dev);
765 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
767 struct platform_device *pdev = to_platform_device(dev);
770 /* Some devices have extra OF data and an OF-style MODALIAS */
771 rc = of_device_uevent_modalias(dev, env);
775 rc = acpi_device_uevent_modalias(dev, env);
779 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
784 static const struct platform_device_id *platform_match_id(
785 const struct platform_device_id *id,
786 struct platform_device *pdev)
788 while (id->name[0]) {
789 if (strcmp(pdev->name, id->name) == 0) {
799 * platform_match - bind platform device to platform driver.
803 * Platform device IDs are assumed to be encoded like this:
804 * "<name><instance>", where <name> is a short description of the type of
805 * device, like "pci" or "floppy", and <instance> is the enumerated
806 * instance of the device, like '0' or '42'. Driver IDs are simply
807 * "<name>". So, extract the <name> from the platform_device structure,
808 * and compare it against the name of the driver. Return whether they match
811 static int platform_match(struct device *dev, struct device_driver *drv)
813 struct platform_device *pdev = to_platform_device(dev);
814 struct platform_driver *pdrv = to_platform_driver(drv);
816 /* When driver_override is set, only bind to the matching driver */
817 if (pdev->driver_override)
818 return !strcmp(pdev->driver_override, drv->name);
820 /* Attempt an OF style match first */
821 if (of_driver_match_device(dev, drv))
824 /* Then try ACPI style match */
825 if (acpi_driver_match_device(dev, drv))
828 /* Then try to match against the id table */
830 return platform_match_id(pdrv->id_table, pdev) != NULL;
832 /* fall-back to driver name match */
833 return (strcmp(pdev->name, drv->name) == 0);
836 #ifdef CONFIG_PM_SLEEP
838 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
840 struct platform_driver *pdrv = to_platform_driver(dev->driver);
841 struct platform_device *pdev = to_platform_device(dev);
844 if (dev->driver && pdrv->suspend)
845 ret = pdrv->suspend(pdev, mesg);
850 static int platform_legacy_resume(struct device *dev)
852 struct platform_driver *pdrv = to_platform_driver(dev->driver);
853 struct platform_device *pdev = to_platform_device(dev);
856 if (dev->driver && pdrv->resume)
857 ret = pdrv->resume(pdev);
862 #endif /* CONFIG_PM_SLEEP */
864 #ifdef CONFIG_SUSPEND
866 int platform_pm_suspend(struct device *dev)
868 struct device_driver *drv = dev->driver;
875 if (drv->pm->suspend)
876 ret = drv->pm->suspend(dev);
878 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
884 int platform_pm_resume(struct device *dev)
886 struct device_driver *drv = dev->driver;
894 ret = drv->pm->resume(dev);
896 ret = platform_legacy_resume(dev);
902 #endif /* CONFIG_SUSPEND */
904 #ifdef CONFIG_HIBERNATE_CALLBACKS
906 int platform_pm_freeze(struct device *dev)
908 struct device_driver *drv = dev->driver;
916 ret = drv->pm->freeze(dev);
918 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
924 int platform_pm_thaw(struct device *dev)
926 struct device_driver *drv = dev->driver;
934 ret = drv->pm->thaw(dev);
936 ret = platform_legacy_resume(dev);
942 int platform_pm_poweroff(struct device *dev)
944 struct device_driver *drv = dev->driver;
951 if (drv->pm->poweroff)
952 ret = drv->pm->poweroff(dev);
954 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
960 int platform_pm_restore(struct device *dev)
962 struct device_driver *drv = dev->driver;
969 if (drv->pm->restore)
970 ret = drv->pm->restore(dev);
972 ret = platform_legacy_resume(dev);
978 #endif /* CONFIG_HIBERNATE_CALLBACKS */
980 static const struct dev_pm_ops platform_dev_pm_ops = {
981 .runtime_suspend = pm_generic_runtime_suspend,
982 .runtime_resume = pm_generic_runtime_resume,
983 USE_PLATFORM_PM_SLEEP_OPS
986 struct bus_type platform_bus_type = {
988 .dev_groups = platform_dev_groups,
989 .match = platform_match,
990 .uevent = platform_uevent,
991 .pm = &platform_dev_pm_ops,
993 EXPORT_SYMBOL_GPL(platform_bus_type);
995 int __init platform_bus_init(void)
999 early_platform_cleanup();
1001 error = device_register(&platform_bus);
1004 error = bus_register(&platform_bus_type);
1006 device_unregister(&platform_bus);
1010 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
1011 u64 dma_get_required_mask(struct device *dev)
1013 u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
1014 u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
1017 if (!high_totalram) {
1018 /* convert to mask just covering totalram */
1019 low_totalram = (1 << (fls(low_totalram) - 1));
1020 low_totalram += low_totalram - 1;
1021 mask = low_totalram;
1023 high_totalram = (1 << (fls(high_totalram) - 1));
1024 high_totalram += high_totalram - 1;
1025 mask = (((u64)high_totalram) << 32) + 0xffffffff;
1029 EXPORT_SYMBOL_GPL(dma_get_required_mask);
1032 static __initdata LIST_HEAD(early_platform_driver_list);
1033 static __initdata LIST_HEAD(early_platform_device_list);
1036 * early_platform_driver_register - register early platform driver
1037 * @epdrv: early_platform driver structure
1038 * @buf: string passed from early_param()
1040 * Helper function for early_platform_init() / early_platform_init_buffer()
1042 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1048 /* Simply add the driver to the end of the global list.
1049 * Drivers will by default be put on the list in compiled-in order.
1051 if (!epdrv->list.next) {
1052 INIT_LIST_HEAD(&epdrv->list);
1053 list_add_tail(&epdrv->list, &early_platform_driver_list);
1056 /* If the user has specified device then make sure the driver
1057 * gets prioritized. The driver of the last device specified on
1058 * command line will be put first on the list.
1060 n = strlen(epdrv->pdrv->driver.name);
1061 if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1062 list_move(&epdrv->list, &early_platform_driver_list);
1064 /* Allow passing parameters after device name */
1065 if (buf[n] == '\0' || buf[n] == ',')
1066 epdrv->requested_id = -1;
1068 epdrv->requested_id = simple_strtoul(&buf[n + 1],
1071 if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1072 epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1075 n += strcspn(&buf[n + 1], ",") + 1;
1081 if (epdrv->bufsize) {
1082 memcpy(epdrv->buffer, &buf[n],
1083 min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1084 epdrv->buffer[epdrv->bufsize - 1] = '\0';
1092 * early_platform_add_devices - adds a number of early platform devices
1093 * @devs: array of early platform devices to add
1094 * @num: number of early platform devices in array
1096 * Used by early architecture code to register early platform devices and
1097 * their platform data.
1099 void __init early_platform_add_devices(struct platform_device **devs, int num)
1104 /* simply add the devices to list */
1105 for (i = 0; i < num; i++) {
1106 dev = &devs[i]->dev;
1108 if (!dev->devres_head.next) {
1109 pm_runtime_early_init(dev);
1110 INIT_LIST_HEAD(&dev->devres_head);
1111 list_add_tail(&dev->devres_head,
1112 &early_platform_device_list);
1118 * early_platform_driver_register_all - register early platform drivers
1119 * @class_str: string to identify early platform driver class
1121 * Used by architecture code to register all early platform drivers
1122 * for a certain class. If omitted then only early platform drivers
1123 * with matching kernel command line class parameters will be registered.
1125 void __init early_platform_driver_register_all(char *class_str)
1127 /* The "class_str" parameter may or may not be present on the kernel
1128 * command line. If it is present then there may be more than one
1129 * matching parameter.
1131 * Since we register our early platform drivers using early_param()
1132 * we need to make sure that they also get registered in the case
1133 * when the parameter is missing from the kernel command line.
1135 * We use parse_early_options() to make sure the early_param() gets
1136 * called at least once. The early_param() may be called more than
1137 * once since the name of the preferred device may be specified on
1138 * the kernel command line. early_platform_driver_register() handles
1141 parse_early_options(class_str);
1145 * early_platform_match - find early platform device matching driver
1146 * @epdrv: early platform driver structure
1147 * @id: id to match against
1149 static struct platform_device * __init
1150 early_platform_match(struct early_platform_driver *epdrv, int id)
1152 struct platform_device *pd;
1154 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1155 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1163 * early_platform_left - check if early platform driver has matching devices
1164 * @epdrv: early platform driver structure
1165 * @id: return true if id or above exists
1167 static int __init early_platform_left(struct early_platform_driver *epdrv,
1170 struct platform_device *pd;
1172 list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1173 if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1181 * early_platform_driver_probe_id - probe drivers matching class_str and id
1182 * @class_str: string to identify early platform driver class
1183 * @id: id to match against
1184 * @nr_probe: number of platform devices to successfully probe before exiting
1186 static int __init early_platform_driver_probe_id(char *class_str,
1190 struct early_platform_driver *epdrv;
1191 struct platform_device *match;
1196 list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1197 /* only use drivers matching our class_str */
1198 if (strcmp(class_str, epdrv->class_str))
1202 match_id = epdrv->requested_id;
1207 left += early_platform_left(epdrv, id);
1209 /* skip requested id */
1210 switch (epdrv->requested_id) {
1211 case EARLY_PLATFORM_ID_ERROR:
1212 case EARLY_PLATFORM_ID_UNSET:
1215 if (epdrv->requested_id == id)
1216 match_id = EARLY_PLATFORM_ID_UNSET;
1221 case EARLY_PLATFORM_ID_ERROR:
1222 pr_warn("%s: unable to parse %s parameter\n",
1223 class_str, epdrv->pdrv->driver.name);
1225 case EARLY_PLATFORM_ID_UNSET:
1229 match = early_platform_match(epdrv, match_id);
1234 * Set up a sensible init_name to enable
1235 * dev_name() and others to be used before the
1236 * rest of the driver core is initialized.
1238 if (!match->dev.init_name && slab_is_available()) {
1239 if (match->id != -1)
1240 match->dev.init_name =
1241 kasprintf(GFP_KERNEL, "%s.%d",
1245 match->dev.init_name =
1246 kasprintf(GFP_KERNEL, "%s",
1249 if (!match->dev.init_name)
1253 if (epdrv->pdrv->probe(match))
1254 pr_warn("%s: unable to probe %s early.\n",
1255 class_str, match->name);
1271 * early_platform_driver_probe - probe a class of registered drivers
1272 * @class_str: string to identify early platform driver class
1273 * @nr_probe: number of platform devices to successfully probe before exiting
1274 * @user_only: only probe user specified early platform devices
1276 * Used by architecture code to probe registered early platform drivers
1277 * within a certain class. For probe to happen a registered early platform
1278 * device matching a registered early platform driver is needed.
1280 int __init early_platform_driver_probe(char *class_str,
1287 for (i = -2; n < nr_probe; i++) {
1288 k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1303 * early_platform_cleanup - clean up early platform code
1305 void __init early_platform_cleanup(void)
1307 struct platform_device *pd, *pd2;
1309 /* clean up the devres list used to chain devices */
1310 list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1312 list_del(&pd->dev.devres_head);
1313 memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));