1 // SPDX-License-Identifier: GPL-2.0
3 * platform.c - platform 'pseudo' bus for legacy devices
5 * Copyright (c) 2002-3 Patrick Mochel
6 * Copyright (c) 2002-3 Open Source Development Labs
8 * Please see Documentation/driver-api/driver-model/platform.rst for more
12 #include <linux/string.h>
13 #include <linux/platform_device.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/memblock.h>
20 #include <linux/err.h>
21 #include <linux/slab.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/pm_domain.h>
24 #include <linux/idr.h>
25 #include <linux/acpi.h>
26 #include <linux/clk/clk-conf.h>
27 #include <linux/limits.h>
28 #include <linux/property.h>
29 #include <linux/kmemleak.h>
30 #include <linux/types.h>
33 #include "power/power.h"
35 /* For automatically allocated device IDs */
36 static DEFINE_IDA(platform_devid_ida);
38 struct device platform_bus = {
39 .init_name = "platform",
41 EXPORT_SYMBOL_GPL(platform_bus);
44 * platform_get_resource - get a resource for a device
45 * @dev: platform device
46 * @type: resource type
47 * @num: resource index
49 struct resource *platform_get_resource(struct platform_device *dev,
50 unsigned int type, unsigned int num)
54 for (i = 0; i < dev->num_resources; i++) {
55 struct resource *r = &dev->resource[i];
57 if (type == resource_type(r) && num-- == 0)
62 EXPORT_SYMBOL_GPL(platform_get_resource);
64 #ifdef CONFIG_HAS_IOMEM
66 * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
67 * platform device and get resource
69 * @pdev: platform device to use both for memory resource lookup as well as
71 * @index: resource index
72 * @res: optional output parameter to store a pointer to the obtained resource.
75 devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
76 unsigned int index, struct resource **res)
80 r = platform_get_resource(pdev, IORESOURCE_MEM, index);
83 return devm_ioremap_resource(&pdev->dev, r);
85 EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
88 * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
91 * @pdev: platform device to use both for memory resource lookup as well as
93 * @index: resource index
95 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
98 return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
100 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
103 * devm_platform_ioremap_resource_wc - write-combined variant of
104 * devm_platform_ioremap_resource()
106 * @pdev: platform device to use both for memory resource lookup as well as
107 * resource management
108 * @index: resource index
110 void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
113 struct resource *res;
115 res = platform_get_resource(pdev, IORESOURCE_MEM, index);
116 return devm_ioremap_resource_wc(&pdev->dev, res);
120 * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
121 * a platform device, retrieve the
124 * @pdev: platform device to use both for memory resource lookup as well as
125 * resource management
126 * @name: name of the resource
129 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
132 struct resource *res;
134 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
135 return devm_ioremap_resource(&pdev->dev, res);
137 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
138 #endif /* CONFIG_HAS_IOMEM */
141 * platform_get_irq_optional - get an optional IRQ for a device
142 * @dev: platform device
143 * @num: IRQ number index
145 * Gets an IRQ for a platform device. Device drivers should check the return
146 * value for errors so as to not pass a negative integer value to the
147 * request_irq() APIs. This is the same as platform_get_irq(), except that it
148 * does not print an error message if an IRQ can not be obtained.
152 * int irq = platform_get_irq_optional(pdev, 0);
156 * Return: IRQ number on success, negative error number on failure.
158 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
161 /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
162 if (!dev || num >= dev->archdata.num_irqs)
164 return dev->archdata.irqs[num];
169 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
170 ret = of_irq_get(dev->dev.of_node, num);
171 if (ret > 0 || ret == -EPROBE_DEFER)
175 r = platform_get_resource(dev, IORESOURCE_IRQ, num);
176 if (has_acpi_companion(&dev->dev)) {
177 if (r && r->flags & IORESOURCE_DISABLED) {
178 ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
185 * The resources may pass trigger flags to the irqs that need
186 * to be set up. It so happens that the trigger flags for
187 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
190 if (r && r->flags & IORESOURCE_BITS) {
191 struct irq_data *irqd;
193 irqd = irq_get_irq_data(r->start);
196 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
203 * For the index 0 interrupt, allow falling back to GpioInt
204 * resources. While a device could have both Interrupt and GpioInt
205 * resources, making this fallback ambiguous, in many common cases
206 * the device will only expose one IRQ, and this fallback
207 * allows a common code path across either kind of resource.
209 if (num == 0 && has_acpi_companion(&dev->dev)) {
210 ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
211 /* Our callers expect -ENXIO for missing IRQs. */
212 if (ret >= 0 || ret == -EPROBE_DEFER)
219 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
222 * platform_get_irq - get an IRQ for a device
223 * @dev: platform device
224 * @num: IRQ number index
226 * Gets an IRQ for a platform device and prints an error message if finding the
227 * IRQ fails. Device drivers should check the return value for errors so as to
228 * not pass a negative integer value to the request_irq() APIs.
232 * int irq = platform_get_irq(pdev, 0);
236 * Return: IRQ number on success, negative error number on failure.
238 int platform_get_irq(struct platform_device *dev, unsigned int num)
242 ret = platform_get_irq_optional(dev, num);
243 if (ret < 0 && ret != -EPROBE_DEFER)
244 dev_err(&dev->dev, "IRQ index %u not found\n", num);
248 EXPORT_SYMBOL_GPL(platform_get_irq);
251 * platform_irq_count - Count the number of IRQs a platform device uses
252 * @dev: platform device
254 * Return: Number of IRQs a platform device uses or EPROBE_DEFER
256 int platform_irq_count(struct platform_device *dev)
260 while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
263 if (ret == -EPROBE_DEFER)
268 EXPORT_SYMBOL_GPL(platform_irq_count);
271 * platform_get_resource_byname - get a resource for a device by name
272 * @dev: platform device
273 * @type: resource type
274 * @name: resource name
276 struct resource *platform_get_resource_byname(struct platform_device *dev,
282 for (i = 0; i < dev->num_resources; i++) {
283 struct resource *r = &dev->resource[i];
285 if (unlikely(!r->name))
288 if (type == resource_type(r) && !strcmp(r->name, name))
293 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
295 static int __platform_get_irq_byname(struct platform_device *dev,
301 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
302 ret = of_irq_get_byname(dev->dev.of_node, name);
303 if (ret > 0 || ret == -EPROBE_DEFER)
307 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
315 * platform_get_irq_byname - get an IRQ for a device by name
316 * @dev: platform device
319 * Get an IRQ like platform_get_irq(), but then by name rather then by index.
321 * Return: IRQ number on success, negative error number on failure.
323 int platform_get_irq_byname(struct platform_device *dev, const char *name)
327 ret = __platform_get_irq_byname(dev, name);
328 if (ret < 0 && ret != -EPROBE_DEFER)
329 dev_err(&dev->dev, "IRQ %s not found\n", name);
333 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
336 * platform_get_irq_byname_optional - get an optional IRQ for a device by name
337 * @dev: platform device
340 * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
341 * does not print an error message if an IRQ can not be obtained.
343 * Return: IRQ number on success, negative error number on failure.
345 int platform_get_irq_byname_optional(struct platform_device *dev,
348 return __platform_get_irq_byname(dev, name);
350 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
353 * platform_add_devices - add a numbers of platform devices
354 * @devs: array of platform devices to add
355 * @num: number of platform devices in array
357 int platform_add_devices(struct platform_device **devs, int num)
361 for (i = 0; i < num; i++) {
362 ret = platform_device_register(devs[i]);
365 platform_device_unregister(devs[i]);
372 EXPORT_SYMBOL_GPL(platform_add_devices);
374 struct platform_object {
375 struct platform_device pdev;
380 * Set up default DMA mask for platform devices if the they weren't
381 * previously set by the architecture / DT.
383 static void setup_pdev_dma_masks(struct platform_device *pdev)
385 pdev->dev.dma_parms = &pdev->dma_parms;
387 if (!pdev->dev.coherent_dma_mask)
388 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
389 if (!pdev->dev.dma_mask) {
390 pdev->platform_dma_mask = DMA_BIT_MASK(32);
391 pdev->dev.dma_mask = &pdev->platform_dma_mask;
396 * platform_device_put - destroy a platform device
397 * @pdev: platform device to free
399 * Free all memory associated with a platform device. This function must
400 * _only_ be externally called in error cases. All other usage is a bug.
402 void platform_device_put(struct platform_device *pdev)
404 if (!IS_ERR_OR_NULL(pdev))
405 put_device(&pdev->dev);
407 EXPORT_SYMBOL_GPL(platform_device_put);
409 static void platform_device_release(struct device *dev)
411 struct platform_object *pa = container_of(dev, struct platform_object,
414 of_device_node_put(&pa->pdev.dev);
415 kfree(pa->pdev.dev.platform_data);
416 kfree(pa->pdev.mfd_cell);
417 kfree(pa->pdev.resource);
418 kfree(pa->pdev.driver_override);
423 * platform_device_alloc - create a platform device
424 * @name: base name of the device we're adding
427 * Create a platform device object which can have other objects attached
428 * to it, and which will have attached objects freed when it is released.
430 struct platform_device *platform_device_alloc(const char *name, int id)
432 struct platform_object *pa;
434 pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
436 strcpy(pa->name, name);
437 pa->pdev.name = pa->name;
439 device_initialize(&pa->pdev.dev);
440 pa->pdev.dev.release = platform_device_release;
441 setup_pdev_dma_masks(&pa->pdev);
444 return pa ? &pa->pdev : NULL;
446 EXPORT_SYMBOL_GPL(platform_device_alloc);
449 * platform_device_add_resources - add resources to a platform device
450 * @pdev: platform device allocated by platform_device_alloc to add resources to
451 * @res: set of resources that needs to be allocated for the device
452 * @num: number of resources
454 * Add a copy of the resources to the platform device. The memory
455 * associated with the resources will be freed when the platform device is
458 int platform_device_add_resources(struct platform_device *pdev,
459 const struct resource *res, unsigned int num)
461 struct resource *r = NULL;
464 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
469 kfree(pdev->resource);
471 pdev->num_resources = num;
474 EXPORT_SYMBOL_GPL(platform_device_add_resources);
477 * platform_device_add_data - add platform-specific data to a platform device
478 * @pdev: platform device allocated by platform_device_alloc to add resources to
479 * @data: platform specific data for this platform device
480 * @size: size of platform specific data
482 * Add a copy of platform specific data to the platform device's
483 * platform_data pointer. The memory associated with the platform data
484 * will be freed when the platform device is released.
486 int platform_device_add_data(struct platform_device *pdev, const void *data,
492 d = kmemdup(data, size, GFP_KERNEL);
497 kfree(pdev->dev.platform_data);
498 pdev->dev.platform_data = d;
501 EXPORT_SYMBOL_GPL(platform_device_add_data);
504 * platform_device_add_properties - add built-in properties to a platform device
505 * @pdev: platform device to add properties to
506 * @properties: null terminated array of properties to add
508 * The function will take deep copy of @properties and attach the copy to the
509 * platform device. The memory associated with properties will be freed when the
510 * platform device is released.
512 int platform_device_add_properties(struct platform_device *pdev,
513 const struct property_entry *properties)
515 return device_add_properties(&pdev->dev, properties);
517 EXPORT_SYMBOL_GPL(platform_device_add_properties);
520 * platform_device_add - add a platform device to device hierarchy
521 * @pdev: platform device we're adding
523 * This is part 2 of platform_device_register(), though may be called
524 * separately _iff_ pdev was allocated by platform_device_alloc().
526 int platform_device_add(struct platform_device *pdev)
534 if (!pdev->dev.parent)
535 pdev->dev.parent = &platform_bus;
537 pdev->dev.bus = &platform_bus_type;
541 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
543 case PLATFORM_DEVID_NONE:
544 dev_set_name(&pdev->dev, "%s", pdev->name);
546 case PLATFORM_DEVID_AUTO:
548 * Automatically allocated device ID. We mark it as such so
549 * that we remember it must be freed, and we append a suffix
550 * to avoid namespace collision with explicit IDs.
552 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
556 pdev->id_auto = true;
557 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
561 for (i = 0; i < pdev->num_resources; i++) {
562 struct resource *p, *r = &pdev->resource[i];
565 r->name = dev_name(&pdev->dev);
569 if (resource_type(r) == IORESOURCE_MEM)
571 else if (resource_type(r) == IORESOURCE_IO)
572 p = &ioport_resource;
576 ret = insert_resource(p, r);
578 dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
584 pr_debug("Registering platform device '%s'. Parent at %s\n",
585 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
587 ret = device_add(&pdev->dev);
593 ida_simple_remove(&platform_devid_ida, pdev->id);
594 pdev->id = PLATFORM_DEVID_AUTO;
598 struct resource *r = &pdev->resource[i];
606 EXPORT_SYMBOL_GPL(platform_device_add);
609 * platform_device_del - remove a platform-level device
610 * @pdev: platform device we're removing
612 * Note that this function will also release all memory- and port-based
613 * resources owned by the device (@dev->resource). This function must
614 * _only_ be externally called in error cases. All other usage is a bug.
616 void platform_device_del(struct platform_device *pdev)
620 if (!IS_ERR_OR_NULL(pdev)) {
621 device_del(&pdev->dev);
624 ida_simple_remove(&platform_devid_ida, pdev->id);
625 pdev->id = PLATFORM_DEVID_AUTO;
628 for (i = 0; i < pdev->num_resources; i++) {
629 struct resource *r = &pdev->resource[i];
635 EXPORT_SYMBOL_GPL(platform_device_del);
638 * platform_device_register - add a platform-level device
639 * @pdev: platform device we're adding
641 int platform_device_register(struct platform_device *pdev)
643 device_initialize(&pdev->dev);
644 setup_pdev_dma_masks(pdev);
645 return platform_device_add(pdev);
647 EXPORT_SYMBOL_GPL(platform_device_register);
650 * platform_device_unregister - unregister a platform-level device
651 * @pdev: platform device we're unregistering
653 * Unregistration is done in 2 steps. First we release all resources
654 * and remove it from the subsystem, then we drop reference count by
655 * calling platform_device_put().
657 void platform_device_unregister(struct platform_device *pdev)
659 platform_device_del(pdev);
660 platform_device_put(pdev);
662 EXPORT_SYMBOL_GPL(platform_device_unregister);
665 * platform_device_register_full - add a platform-level device with
666 * resources and platform-specific data
668 * @pdevinfo: data used to create device
670 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
672 struct platform_device *platform_device_register_full(
673 const struct platform_device_info *pdevinfo)
676 struct platform_device *pdev;
678 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
680 return ERR_PTR(-ENOMEM);
682 pdev->dev.parent = pdevinfo->parent;
683 pdev->dev.fwnode = pdevinfo->fwnode;
684 pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
685 pdev->dev.of_node_reused = pdevinfo->of_node_reused;
687 if (pdevinfo->dma_mask) {
688 pdev->platform_dma_mask = pdevinfo->dma_mask;
689 pdev->dev.dma_mask = &pdev->platform_dma_mask;
690 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
693 ret = platform_device_add_resources(pdev,
694 pdevinfo->res, pdevinfo->num_res);
698 ret = platform_device_add_data(pdev,
699 pdevinfo->data, pdevinfo->size_data);
703 if (pdevinfo->properties) {
704 ret = platform_device_add_properties(pdev,
705 pdevinfo->properties);
710 ret = platform_device_add(pdev);
713 ACPI_COMPANION_SET(&pdev->dev, NULL);
714 platform_device_put(pdev);
720 EXPORT_SYMBOL_GPL(platform_device_register_full);
722 static int platform_drv_probe(struct device *_dev)
724 struct platform_driver *drv = to_platform_driver(_dev->driver);
725 struct platform_device *dev = to_platform_device(_dev);
728 ret = of_clk_set_defaults(_dev->of_node, false);
732 ret = dev_pm_domain_attach(_dev, true);
737 ret = drv->probe(dev);
739 dev_pm_domain_detach(_dev, true);
743 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
744 dev_warn(_dev, "probe deferral not supported\n");
751 static int platform_drv_probe_fail(struct device *_dev)
756 static int platform_drv_remove(struct device *_dev)
758 struct platform_driver *drv = to_platform_driver(_dev->driver);
759 struct platform_device *dev = to_platform_device(_dev);
763 ret = drv->remove(dev);
764 dev_pm_domain_detach(_dev, true);
769 static void platform_drv_shutdown(struct device *_dev)
771 struct platform_driver *drv = to_platform_driver(_dev->driver);
772 struct platform_device *dev = to_platform_device(_dev);
779 * __platform_driver_register - register a driver for platform-level devices
780 * @drv: platform driver structure
781 * @owner: owning module/driver
783 int __platform_driver_register(struct platform_driver *drv,
784 struct module *owner)
786 drv->driver.owner = owner;
787 drv->driver.bus = &platform_bus_type;
788 drv->driver.probe = platform_drv_probe;
789 drv->driver.remove = platform_drv_remove;
790 drv->driver.shutdown = platform_drv_shutdown;
792 return driver_register(&drv->driver);
794 EXPORT_SYMBOL_GPL(__platform_driver_register);
797 * platform_driver_unregister - unregister a driver for platform-level devices
798 * @drv: platform driver structure
800 void platform_driver_unregister(struct platform_driver *drv)
802 driver_unregister(&drv->driver);
804 EXPORT_SYMBOL_GPL(platform_driver_unregister);
807 * __platform_driver_probe - register driver for non-hotpluggable device
808 * @drv: platform driver structure
809 * @probe: the driver probe routine, probably from an __init section
810 * @module: module which will be the owner of the driver
812 * Use this instead of platform_driver_register() when you know the device
813 * is not hotpluggable and has already been registered, and you want to
814 * remove its run-once probe() infrastructure from memory after the driver
815 * has bound to the device.
817 * One typical use for this would be with drivers for controllers integrated
818 * into system-on-chip processors, where the controller devices have been
819 * configured as part of board setup.
821 * Note that this is incompatible with deferred probing.
823 * Returns zero if the driver registered and bound to a device, else returns
824 * a negative error code and with the driver not registered.
826 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
827 int (*probe)(struct platform_device *), struct module *module)
831 if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
832 pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
833 drv->driver.name, __func__);
838 * We have to run our probes synchronously because we check if
839 * we find any devices to bind to and exit with error if there
842 drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
845 * Prevent driver from requesting probe deferral to avoid further
846 * futile probe attempts.
848 drv->prevent_deferred_probe = true;
850 /* make sure driver won't have bind/unbind attributes */
851 drv->driver.suppress_bind_attrs = true;
853 /* temporary section violation during probe() */
855 retval = code = __platform_driver_register(drv, module);
858 * Fixup that section violation, being paranoid about code scanning
859 * the list of drivers in order to probe new devices. Check to see
860 * if the probe was successful, and make sure any forced probes of
863 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
865 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
867 drv->driver.probe = platform_drv_probe_fail;
868 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
871 platform_driver_unregister(drv);
874 EXPORT_SYMBOL_GPL(__platform_driver_probe);
877 * __platform_create_bundle - register driver and create corresponding device
878 * @driver: platform driver structure
879 * @probe: the driver probe routine, probably from an __init section
880 * @res: set of resources that needs to be allocated for the device
881 * @n_res: number of resources
882 * @data: platform specific data for this platform device
883 * @size: size of platform specific data
884 * @module: module which will be the owner of the driver
886 * Use this in legacy-style modules that probe hardware directly and
887 * register a single platform device and corresponding platform driver.
889 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
891 struct platform_device * __init_or_module __platform_create_bundle(
892 struct platform_driver *driver,
893 int (*probe)(struct platform_device *),
894 struct resource *res, unsigned int n_res,
895 const void *data, size_t size, struct module *module)
897 struct platform_device *pdev;
900 pdev = platform_device_alloc(driver->driver.name, -1);
906 error = platform_device_add_resources(pdev, res, n_res);
910 error = platform_device_add_data(pdev, data, size);
914 error = platform_device_add(pdev);
918 error = __platform_driver_probe(driver, probe, module);
925 platform_device_del(pdev);
927 platform_device_put(pdev);
929 return ERR_PTR(error);
931 EXPORT_SYMBOL_GPL(__platform_create_bundle);
934 * __platform_register_drivers - register an array of platform drivers
935 * @drivers: an array of drivers to register
936 * @count: the number of drivers to register
937 * @owner: module owning the drivers
939 * Registers platform drivers specified by an array. On failure to register a
940 * driver, all previously registered drivers will be unregistered. Callers of
941 * this API should use platform_unregister_drivers() to unregister drivers in
944 * Returns: 0 on success or a negative error code on failure.
946 int __platform_register_drivers(struct platform_driver * const *drivers,
947 unsigned int count, struct module *owner)
952 for (i = 0; i < count; i++) {
953 pr_debug("registering platform driver %ps\n", drivers[i]);
955 err = __platform_driver_register(drivers[i], owner);
957 pr_err("failed to register platform driver %ps: %d\n",
967 pr_debug("unregistering platform driver %ps\n", drivers[i]);
968 platform_driver_unregister(drivers[i]);
973 EXPORT_SYMBOL_GPL(__platform_register_drivers);
976 * platform_unregister_drivers - unregister an array of platform drivers
977 * @drivers: an array of drivers to unregister
978 * @count: the number of drivers to unregister
980 * Unegisters platform drivers specified by an array. This is typically used
981 * to complement an earlier call to platform_register_drivers(). Drivers are
982 * unregistered in the reverse order in which they were registered.
984 void platform_unregister_drivers(struct platform_driver * const *drivers,
988 pr_debug("unregistering platform driver %ps\n", drivers[count]);
989 platform_driver_unregister(drivers[count]);
992 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
994 /* modalias support enables more hands-off userspace setup:
995 * (a) environment variable lets new-style hotplug events work once system is
996 * fully running: "modprobe $MODALIAS"
997 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
998 * mishandled before system is fully running: "modprobe $(cat modalias)"
1000 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
1003 struct platform_device *pdev = to_platform_device(dev);
1006 len = of_device_modalias(dev, buf, PAGE_SIZE);
1010 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
1014 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
1016 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
1018 static DEVICE_ATTR_RO(modalias);
1020 static ssize_t driver_override_store(struct device *dev,
1021 struct device_attribute *attr,
1022 const char *buf, size_t count)
1024 struct platform_device *pdev = to_platform_device(dev);
1025 char *driver_override, *old, *cp;
1027 /* We need to keep extra room for a newline */
1028 if (count >= (PAGE_SIZE - 1))
1031 driver_override = kstrndup(buf, count, GFP_KERNEL);
1032 if (!driver_override)
1035 cp = strchr(driver_override, '\n');
1040 old = pdev->driver_override;
1041 if (strlen(driver_override)) {
1042 pdev->driver_override = driver_override;
1044 kfree(driver_override);
1045 pdev->driver_override = NULL;
1054 static ssize_t driver_override_show(struct device *dev,
1055 struct device_attribute *attr, char *buf)
1057 struct platform_device *pdev = to_platform_device(dev);
1061 len = sprintf(buf, "%s\n", pdev->driver_override);
1065 static DEVICE_ATTR_RW(driver_override);
1068 static struct attribute *platform_dev_attrs[] = {
1069 &dev_attr_modalias.attr,
1070 &dev_attr_driver_override.attr,
1073 ATTRIBUTE_GROUPS(platform_dev);
1075 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1077 struct platform_device *pdev = to_platform_device(dev);
1080 /* Some devices have extra OF data and an OF-style MODALIAS */
1081 rc = of_device_uevent_modalias(dev, env);
1085 rc = acpi_device_uevent_modalias(dev, env);
1089 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1094 static const struct platform_device_id *platform_match_id(
1095 const struct platform_device_id *id,
1096 struct platform_device *pdev)
1098 while (id->name[0]) {
1099 if (strcmp(pdev->name, id->name) == 0) {
1100 pdev->id_entry = id;
1109 * platform_match - bind platform device to platform driver.
1113 * Platform device IDs are assumed to be encoded like this:
1114 * "<name><instance>", where <name> is a short description of the type of
1115 * device, like "pci" or "floppy", and <instance> is the enumerated
1116 * instance of the device, like '0' or '42'. Driver IDs are simply
1117 * "<name>". So, extract the <name> from the platform_device structure,
1118 * and compare it against the name of the driver. Return whether they match
1121 static int platform_match(struct device *dev, struct device_driver *drv)
1123 struct platform_device *pdev = to_platform_device(dev);
1124 struct platform_driver *pdrv = to_platform_driver(drv);
1126 /* When driver_override is set, only bind to the matching driver */
1127 if (pdev->driver_override)
1128 return !strcmp(pdev->driver_override, drv->name);
1130 /* Attempt an OF style match first */
1131 if (of_driver_match_device(dev, drv))
1134 /* Then try ACPI style match */
1135 if (acpi_driver_match_device(dev, drv))
1138 /* Then try to match against the id table */
1140 return platform_match_id(pdrv->id_table, pdev) != NULL;
1142 /* fall-back to driver name match */
1143 return (strcmp(pdev->name, drv->name) == 0);
1146 #ifdef CONFIG_PM_SLEEP
1148 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1150 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1151 struct platform_device *pdev = to_platform_device(dev);
1154 if (dev->driver && pdrv->suspend)
1155 ret = pdrv->suspend(pdev, mesg);
1160 static int platform_legacy_resume(struct device *dev)
1162 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1163 struct platform_device *pdev = to_platform_device(dev);
1166 if (dev->driver && pdrv->resume)
1167 ret = pdrv->resume(pdev);
1172 #endif /* CONFIG_PM_SLEEP */
1174 #ifdef CONFIG_SUSPEND
1176 int platform_pm_suspend(struct device *dev)
1178 struct device_driver *drv = dev->driver;
1185 if (drv->pm->suspend)
1186 ret = drv->pm->suspend(dev);
1188 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1194 int platform_pm_resume(struct device *dev)
1196 struct device_driver *drv = dev->driver;
1203 if (drv->pm->resume)
1204 ret = drv->pm->resume(dev);
1206 ret = platform_legacy_resume(dev);
1212 #endif /* CONFIG_SUSPEND */
1214 #ifdef CONFIG_HIBERNATE_CALLBACKS
1216 int platform_pm_freeze(struct device *dev)
1218 struct device_driver *drv = dev->driver;
1225 if (drv->pm->freeze)
1226 ret = drv->pm->freeze(dev);
1228 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1234 int platform_pm_thaw(struct device *dev)
1236 struct device_driver *drv = dev->driver;
1244 ret = drv->pm->thaw(dev);
1246 ret = platform_legacy_resume(dev);
1252 int platform_pm_poweroff(struct device *dev)
1254 struct device_driver *drv = dev->driver;
1261 if (drv->pm->poweroff)
1262 ret = drv->pm->poweroff(dev);
1264 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1270 int platform_pm_restore(struct device *dev)
1272 struct device_driver *drv = dev->driver;
1279 if (drv->pm->restore)
1280 ret = drv->pm->restore(dev);
1282 ret = platform_legacy_resume(dev);
1288 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1290 int platform_dma_configure(struct device *dev)
1292 enum dev_dma_attr attr;
1296 ret = of_dma_configure(dev, dev->of_node, true);
1297 } else if (has_acpi_companion(dev)) {
1298 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1299 ret = acpi_dma_configure(dev, attr);
1305 static const struct dev_pm_ops platform_dev_pm_ops = {
1306 .runtime_suspend = pm_generic_runtime_suspend,
1307 .runtime_resume = pm_generic_runtime_resume,
1308 USE_PLATFORM_PM_SLEEP_OPS
1311 struct bus_type platform_bus_type = {
1313 .dev_groups = platform_dev_groups,
1314 .match = platform_match,
1315 .uevent = platform_uevent,
1316 .dma_configure = platform_dma_configure,
1317 .pm = &platform_dev_pm_ops,
1319 EXPORT_SYMBOL_GPL(platform_bus_type);
1321 static inline int __platform_match(struct device *dev, const void *drv)
1323 return platform_match(dev, (struct device_driver *)drv);
1327 * platform_find_device_by_driver - Find a platform device with a given
1329 * @start: The device to start the search from.
1330 * @drv: The device driver to look for.
1332 struct device *platform_find_device_by_driver(struct device *start,
1333 const struct device_driver *drv)
1335 return bus_find_device(&platform_bus_type, start, drv,
1338 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1340 void __weak __init early_platform_cleanup(void) { }
1342 int __init platform_bus_init(void)
1346 early_platform_cleanup();
1348 error = device_register(&platform_bus);
1350 put_device(&platform_bus);
1353 error = bus_register(&platform_bus_type);
1355 device_unregister(&platform_bus);
1356 of_platform_register_reconfig_notifier();