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.
151 * int irq = platform_get_irq_optional(pdev, 0);
155 * Return: IRQ number on success, negative error number on failure.
157 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
160 /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
161 if (!dev || num >= dev->archdata.num_irqs)
163 return dev->archdata.irqs[num];
168 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
169 ret = of_irq_get(dev->dev.of_node, num);
170 if (ret > 0 || ret == -EPROBE_DEFER)
174 r = platform_get_resource(dev, IORESOURCE_IRQ, num);
175 if (has_acpi_companion(&dev->dev)) {
176 if (r && r->flags & IORESOURCE_DISABLED) {
177 ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
184 * The resources may pass trigger flags to the irqs that need
185 * to be set up. It so happens that the trigger flags for
186 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
189 if (r && r->flags & IORESOURCE_BITS) {
190 struct irq_data *irqd;
192 irqd = irq_get_irq_data(r->start);
195 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
202 * For the index 0 interrupt, allow falling back to GpioInt
203 * resources. While a device could have both Interrupt and GpioInt
204 * resources, making this fallback ambiguous, in many common cases
205 * the device will only expose one IRQ, and this fallback
206 * allows a common code path across either kind of resource.
208 if (num == 0 && has_acpi_companion(&dev->dev)) {
209 ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
210 /* Our callers expect -ENXIO for missing IRQs. */
211 if (ret >= 0 || ret == -EPROBE_DEFER)
218 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
221 * platform_get_irq - get an IRQ for a device
222 * @dev: platform device
223 * @num: IRQ number index
225 * Gets an IRQ for a platform device and prints an error message if finding the
226 * IRQ fails. Device drivers should check the return value for errors so as to
227 * not pass a negative integer value to the request_irq() APIs.
230 * int irq = platform_get_irq(pdev, 0);
234 * Return: IRQ number on success, negative error number on failure.
236 int platform_get_irq(struct platform_device *dev, unsigned int num)
240 ret = platform_get_irq_optional(dev, num);
241 if (ret < 0 && ret != -EPROBE_DEFER)
242 dev_err(&dev->dev, "IRQ index %u not found\n", num);
246 EXPORT_SYMBOL_GPL(platform_get_irq);
249 * platform_irq_count - Count the number of IRQs a platform device uses
250 * @dev: platform device
252 * Return: Number of IRQs a platform device uses or EPROBE_DEFER
254 int platform_irq_count(struct platform_device *dev)
258 while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
261 if (ret == -EPROBE_DEFER)
266 EXPORT_SYMBOL_GPL(platform_irq_count);
269 * platform_get_resource_byname - get a resource for a device by name
270 * @dev: platform device
271 * @type: resource type
272 * @name: resource name
274 struct resource *platform_get_resource_byname(struct platform_device *dev,
280 for (i = 0; i < dev->num_resources; i++) {
281 struct resource *r = &dev->resource[i];
283 if (unlikely(!r->name))
286 if (type == resource_type(r) && !strcmp(r->name, name))
291 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
293 static int __platform_get_irq_byname(struct platform_device *dev,
299 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
300 ret = of_irq_get_byname(dev->dev.of_node, name);
301 if (ret > 0 || ret == -EPROBE_DEFER)
305 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
313 * platform_get_irq_byname - get an IRQ for a device by name
314 * @dev: platform device
317 * Get an IRQ like platform_get_irq(), but then by name rather then by index.
319 * Return: IRQ number on success, negative error number on failure.
321 int platform_get_irq_byname(struct platform_device *dev, const char *name)
325 ret = __platform_get_irq_byname(dev, name);
326 if (ret < 0 && ret != -EPROBE_DEFER)
327 dev_err(&dev->dev, "IRQ %s not found\n", name);
331 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
334 * platform_get_irq_byname_optional - get an optional IRQ for a device by name
335 * @dev: platform device
338 * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
339 * does not print an error message if an IRQ can not be obtained.
341 * Return: IRQ number on success, negative error number on failure.
343 int platform_get_irq_byname_optional(struct platform_device *dev,
346 return __platform_get_irq_byname(dev, name);
348 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
351 * platform_add_devices - add a numbers of platform devices
352 * @devs: array of platform devices to add
353 * @num: number of platform devices in array
355 int platform_add_devices(struct platform_device **devs, int num)
359 for (i = 0; i < num; i++) {
360 ret = platform_device_register(devs[i]);
363 platform_device_unregister(devs[i]);
370 EXPORT_SYMBOL_GPL(platform_add_devices);
372 struct platform_object {
373 struct platform_device pdev;
378 * Set up default DMA mask for platform devices if the they weren't
379 * previously set by the architecture / DT.
381 static void setup_pdev_dma_masks(struct platform_device *pdev)
383 if (!pdev->dev.coherent_dma_mask)
384 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
385 if (!pdev->dev.dma_mask) {
386 pdev->platform_dma_mask = DMA_BIT_MASK(32);
387 pdev->dev.dma_mask = &pdev->platform_dma_mask;
392 * platform_device_put - destroy a platform device
393 * @pdev: platform device to free
395 * Free all memory associated with a platform device. This function must
396 * _only_ be externally called in error cases. All other usage is a bug.
398 void platform_device_put(struct platform_device *pdev)
400 if (!IS_ERR_OR_NULL(pdev))
401 put_device(&pdev->dev);
403 EXPORT_SYMBOL_GPL(platform_device_put);
405 static void platform_device_release(struct device *dev)
407 struct platform_object *pa = container_of(dev, struct platform_object,
410 of_device_node_put(&pa->pdev.dev);
411 kfree(pa->pdev.dev.platform_data);
412 kfree(pa->pdev.mfd_cell);
413 kfree(pa->pdev.resource);
414 kfree(pa->pdev.driver_override);
419 * platform_device_alloc - create a platform device
420 * @name: base name of the device we're adding
423 * Create a platform device object which can have other objects attached
424 * to it, and which will have attached objects freed when it is released.
426 struct platform_device *platform_device_alloc(const char *name, int id)
428 struct platform_object *pa;
430 pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
432 strcpy(pa->name, name);
433 pa->pdev.name = pa->name;
435 device_initialize(&pa->pdev.dev);
436 pa->pdev.dev.release = platform_device_release;
437 setup_pdev_dma_masks(&pa->pdev);
440 return pa ? &pa->pdev : NULL;
442 EXPORT_SYMBOL_GPL(platform_device_alloc);
445 * platform_device_add_resources - add resources to a platform device
446 * @pdev: platform device allocated by platform_device_alloc to add resources to
447 * @res: set of resources that needs to be allocated for the device
448 * @num: number of resources
450 * Add a copy of the resources to the platform device. The memory
451 * associated with the resources will be freed when the platform device is
454 int platform_device_add_resources(struct platform_device *pdev,
455 const struct resource *res, unsigned int num)
457 struct resource *r = NULL;
460 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
465 kfree(pdev->resource);
467 pdev->num_resources = num;
470 EXPORT_SYMBOL_GPL(platform_device_add_resources);
473 * platform_device_add_data - add platform-specific data to a platform device
474 * @pdev: platform device allocated by platform_device_alloc to add resources to
475 * @data: platform specific data for this platform device
476 * @size: size of platform specific data
478 * Add a copy of platform specific data to the platform device's
479 * platform_data pointer. The memory associated with the platform data
480 * will be freed when the platform device is released.
482 int platform_device_add_data(struct platform_device *pdev, const void *data,
488 d = kmemdup(data, size, GFP_KERNEL);
493 kfree(pdev->dev.platform_data);
494 pdev->dev.platform_data = d;
497 EXPORT_SYMBOL_GPL(platform_device_add_data);
500 * platform_device_add_properties - add built-in properties to a platform device
501 * @pdev: platform device to add properties to
502 * @properties: null terminated array of properties to add
504 * The function will take deep copy of @properties and attach the copy to the
505 * platform device. The memory associated with properties will be freed when the
506 * platform device is released.
508 int platform_device_add_properties(struct platform_device *pdev,
509 const struct property_entry *properties)
511 return device_add_properties(&pdev->dev, properties);
513 EXPORT_SYMBOL_GPL(platform_device_add_properties);
516 * platform_device_add - add a platform device to device hierarchy
517 * @pdev: platform device we're adding
519 * This is part 2 of platform_device_register(), though may be called
520 * separately _iff_ pdev was allocated by platform_device_alloc().
522 int platform_device_add(struct platform_device *pdev)
530 if (!pdev->dev.parent)
531 pdev->dev.parent = &platform_bus;
533 pdev->dev.bus = &platform_bus_type;
537 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
539 case PLATFORM_DEVID_NONE:
540 dev_set_name(&pdev->dev, "%s", pdev->name);
542 case PLATFORM_DEVID_AUTO:
544 * Automatically allocated device ID. We mark it as such so
545 * that we remember it must be freed, and we append a suffix
546 * to avoid namespace collision with explicit IDs.
548 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
552 pdev->id_auto = true;
553 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
557 for (i = 0; i < pdev->num_resources; i++) {
558 struct resource *p, *r = &pdev->resource[i];
561 r->name = dev_name(&pdev->dev);
565 if (resource_type(r) == IORESOURCE_MEM)
567 else if (resource_type(r) == IORESOURCE_IO)
568 p = &ioport_resource;
572 ret = insert_resource(p, r);
574 dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
580 pr_debug("Registering platform device '%s'. Parent at %s\n",
581 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
583 ret = device_add(&pdev->dev);
589 ida_simple_remove(&platform_devid_ida, pdev->id);
590 pdev->id = PLATFORM_DEVID_AUTO;
594 struct resource *r = &pdev->resource[i];
602 EXPORT_SYMBOL_GPL(platform_device_add);
605 * platform_device_del - remove a platform-level device
606 * @pdev: platform device we're removing
608 * Note that this function will also release all memory- and port-based
609 * resources owned by the device (@dev->resource). This function must
610 * _only_ be externally called in error cases. All other usage is a bug.
612 void platform_device_del(struct platform_device *pdev)
616 if (!IS_ERR_OR_NULL(pdev)) {
617 device_del(&pdev->dev);
620 ida_simple_remove(&platform_devid_ida, pdev->id);
621 pdev->id = PLATFORM_DEVID_AUTO;
624 for (i = 0; i < pdev->num_resources; i++) {
625 struct resource *r = &pdev->resource[i];
631 EXPORT_SYMBOL_GPL(platform_device_del);
634 * platform_device_register - add a platform-level device
635 * @pdev: platform device we're adding
637 int platform_device_register(struct platform_device *pdev)
639 device_initialize(&pdev->dev);
640 setup_pdev_dma_masks(pdev);
641 return platform_device_add(pdev);
643 EXPORT_SYMBOL_GPL(platform_device_register);
646 * platform_device_unregister - unregister a platform-level device
647 * @pdev: platform device we're unregistering
649 * Unregistration is done in 2 steps. First we release all resources
650 * and remove it from the subsystem, then we drop reference count by
651 * calling platform_device_put().
653 void platform_device_unregister(struct platform_device *pdev)
655 platform_device_del(pdev);
656 platform_device_put(pdev);
658 EXPORT_SYMBOL_GPL(platform_device_unregister);
661 * platform_device_register_full - add a platform-level device with
662 * resources and platform-specific data
664 * @pdevinfo: data used to create device
666 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
668 struct platform_device *platform_device_register_full(
669 const struct platform_device_info *pdevinfo)
672 struct platform_device *pdev;
674 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
676 return ERR_PTR(-ENOMEM);
678 pdev->dev.parent = pdevinfo->parent;
679 pdev->dev.fwnode = pdevinfo->fwnode;
680 pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
681 pdev->dev.of_node_reused = pdevinfo->of_node_reused;
683 if (pdevinfo->dma_mask) {
684 pdev->platform_dma_mask = pdevinfo->dma_mask;
685 pdev->dev.dma_mask = &pdev->platform_dma_mask;
686 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
689 ret = platform_device_add_resources(pdev,
690 pdevinfo->res, pdevinfo->num_res);
694 ret = platform_device_add_data(pdev,
695 pdevinfo->data, pdevinfo->size_data);
699 if (pdevinfo->properties) {
700 ret = platform_device_add_properties(pdev,
701 pdevinfo->properties);
706 ret = platform_device_add(pdev);
709 ACPI_COMPANION_SET(&pdev->dev, NULL);
710 platform_device_put(pdev);
716 EXPORT_SYMBOL_GPL(platform_device_register_full);
718 static int platform_drv_probe(struct device *_dev)
720 struct platform_driver *drv = to_platform_driver(_dev->driver);
721 struct platform_device *dev = to_platform_device(_dev);
724 ret = of_clk_set_defaults(_dev->of_node, false);
728 ret = dev_pm_domain_attach(_dev, true);
733 ret = drv->probe(dev);
735 dev_pm_domain_detach(_dev, true);
739 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
740 dev_warn(_dev, "probe deferral not supported\n");
747 static int platform_drv_probe_fail(struct device *_dev)
752 static int platform_drv_remove(struct device *_dev)
754 struct platform_driver *drv = to_platform_driver(_dev->driver);
755 struct platform_device *dev = to_platform_device(_dev);
759 ret = drv->remove(dev);
760 dev_pm_domain_detach(_dev, true);
765 static void platform_drv_shutdown(struct device *_dev)
767 struct platform_driver *drv = to_platform_driver(_dev->driver);
768 struct platform_device *dev = to_platform_device(_dev);
775 * __platform_driver_register - register a driver for platform-level devices
776 * @drv: platform driver structure
777 * @owner: owning module/driver
779 int __platform_driver_register(struct platform_driver *drv,
780 struct module *owner)
782 drv->driver.owner = owner;
783 drv->driver.bus = &platform_bus_type;
784 drv->driver.probe = platform_drv_probe;
785 drv->driver.remove = platform_drv_remove;
786 drv->driver.shutdown = platform_drv_shutdown;
788 return driver_register(&drv->driver);
790 EXPORT_SYMBOL_GPL(__platform_driver_register);
793 * platform_driver_unregister - unregister a driver for platform-level devices
794 * @drv: platform driver structure
796 void platform_driver_unregister(struct platform_driver *drv)
798 driver_unregister(&drv->driver);
800 EXPORT_SYMBOL_GPL(platform_driver_unregister);
803 * __platform_driver_probe - register driver for non-hotpluggable device
804 * @drv: platform driver structure
805 * @probe: the driver probe routine, probably from an __init section
806 * @module: module which will be the owner of the driver
808 * Use this instead of platform_driver_register() when you know the device
809 * is not hotpluggable and has already been registered, and you want to
810 * remove its run-once probe() infrastructure from memory after the driver
811 * has bound to the device.
813 * One typical use for this would be with drivers for controllers integrated
814 * into system-on-chip processors, where the controller devices have been
815 * configured as part of board setup.
817 * Note that this is incompatible with deferred probing.
819 * Returns zero if the driver registered and bound to a device, else returns
820 * a negative error code and with the driver not registered.
822 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
823 int (*probe)(struct platform_device *), struct module *module)
827 if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
828 pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
829 drv->driver.name, __func__);
834 * We have to run our probes synchronously because we check if
835 * we find any devices to bind to and exit with error if there
838 drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
841 * Prevent driver from requesting probe deferral to avoid further
842 * futile probe attempts.
844 drv->prevent_deferred_probe = true;
846 /* make sure driver won't have bind/unbind attributes */
847 drv->driver.suppress_bind_attrs = true;
849 /* temporary section violation during probe() */
851 retval = code = __platform_driver_register(drv, module);
854 * Fixup that section violation, being paranoid about code scanning
855 * the list of drivers in order to probe new devices. Check to see
856 * if the probe was successful, and make sure any forced probes of
859 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
861 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
863 drv->driver.probe = platform_drv_probe_fail;
864 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
867 platform_driver_unregister(drv);
870 EXPORT_SYMBOL_GPL(__platform_driver_probe);
873 * __platform_create_bundle - register driver and create corresponding device
874 * @driver: platform driver structure
875 * @probe: the driver probe routine, probably from an __init section
876 * @res: set of resources that needs to be allocated for the device
877 * @n_res: number of resources
878 * @data: platform specific data for this platform device
879 * @size: size of platform specific data
880 * @module: module which will be the owner of the driver
882 * Use this in legacy-style modules that probe hardware directly and
883 * register a single platform device and corresponding platform driver.
885 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
887 struct platform_device * __init_or_module __platform_create_bundle(
888 struct platform_driver *driver,
889 int (*probe)(struct platform_device *),
890 struct resource *res, unsigned int n_res,
891 const void *data, size_t size, struct module *module)
893 struct platform_device *pdev;
896 pdev = platform_device_alloc(driver->driver.name, -1);
902 error = platform_device_add_resources(pdev, res, n_res);
906 error = platform_device_add_data(pdev, data, size);
910 error = platform_device_add(pdev);
914 error = __platform_driver_probe(driver, probe, module);
921 platform_device_del(pdev);
923 platform_device_put(pdev);
925 return ERR_PTR(error);
927 EXPORT_SYMBOL_GPL(__platform_create_bundle);
930 * __platform_register_drivers - register an array of platform drivers
931 * @drivers: an array of drivers to register
932 * @count: the number of drivers to register
933 * @owner: module owning the drivers
935 * Registers platform drivers specified by an array. On failure to register a
936 * driver, all previously registered drivers will be unregistered. Callers of
937 * this API should use platform_unregister_drivers() to unregister drivers in
940 * Returns: 0 on success or a negative error code on failure.
942 int __platform_register_drivers(struct platform_driver * const *drivers,
943 unsigned int count, struct module *owner)
948 for (i = 0; i < count; i++) {
949 pr_debug("registering platform driver %ps\n", drivers[i]);
951 err = __platform_driver_register(drivers[i], owner);
953 pr_err("failed to register platform driver %ps: %d\n",
963 pr_debug("unregistering platform driver %ps\n", drivers[i]);
964 platform_driver_unregister(drivers[i]);
969 EXPORT_SYMBOL_GPL(__platform_register_drivers);
972 * platform_unregister_drivers - unregister an array of platform drivers
973 * @drivers: an array of drivers to unregister
974 * @count: the number of drivers to unregister
976 * Unegisters platform drivers specified by an array. This is typically used
977 * to complement an earlier call to platform_register_drivers(). Drivers are
978 * unregistered in the reverse order in which they were registered.
980 void platform_unregister_drivers(struct platform_driver * const *drivers,
984 pr_debug("unregistering platform driver %ps\n", drivers[count]);
985 platform_driver_unregister(drivers[count]);
988 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
990 /* modalias support enables more hands-off userspace setup:
991 * (a) environment variable lets new-style hotplug events work once system is
992 * fully running: "modprobe $MODALIAS"
993 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
994 * mishandled before system is fully running: "modprobe $(cat modalias)"
996 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
999 struct platform_device *pdev = to_platform_device(dev);
1002 len = of_device_modalias(dev, buf, PAGE_SIZE);
1006 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
1010 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
1012 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
1014 static DEVICE_ATTR_RO(modalias);
1016 static ssize_t driver_override_store(struct device *dev,
1017 struct device_attribute *attr,
1018 const char *buf, size_t count)
1020 struct platform_device *pdev = to_platform_device(dev);
1021 char *driver_override, *old, *cp;
1023 /* We need to keep extra room for a newline */
1024 if (count >= (PAGE_SIZE - 1))
1027 driver_override = kstrndup(buf, count, GFP_KERNEL);
1028 if (!driver_override)
1031 cp = strchr(driver_override, '\n');
1036 old = pdev->driver_override;
1037 if (strlen(driver_override)) {
1038 pdev->driver_override = driver_override;
1040 kfree(driver_override);
1041 pdev->driver_override = NULL;
1050 static ssize_t driver_override_show(struct device *dev,
1051 struct device_attribute *attr, char *buf)
1053 struct platform_device *pdev = to_platform_device(dev);
1057 len = sprintf(buf, "%s\n", pdev->driver_override);
1061 static DEVICE_ATTR_RW(driver_override);
1064 static struct attribute *platform_dev_attrs[] = {
1065 &dev_attr_modalias.attr,
1066 &dev_attr_driver_override.attr,
1069 ATTRIBUTE_GROUPS(platform_dev);
1071 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1073 struct platform_device *pdev = to_platform_device(dev);
1076 /* Some devices have extra OF data and an OF-style MODALIAS */
1077 rc = of_device_uevent_modalias(dev, env);
1081 rc = acpi_device_uevent_modalias(dev, env);
1085 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1090 static const struct platform_device_id *platform_match_id(
1091 const struct platform_device_id *id,
1092 struct platform_device *pdev)
1094 while (id->name[0]) {
1095 if (strcmp(pdev->name, id->name) == 0) {
1096 pdev->id_entry = id;
1105 * platform_match - bind platform device to platform driver.
1109 * Platform device IDs are assumed to be encoded like this:
1110 * "<name><instance>", where <name> is a short description of the type of
1111 * device, like "pci" or "floppy", and <instance> is the enumerated
1112 * instance of the device, like '0' or '42'. Driver IDs are simply
1113 * "<name>". So, extract the <name> from the platform_device structure,
1114 * and compare it against the name of the driver. Return whether they match
1117 static int platform_match(struct device *dev, struct device_driver *drv)
1119 struct platform_device *pdev = to_platform_device(dev);
1120 struct platform_driver *pdrv = to_platform_driver(drv);
1122 /* When driver_override is set, only bind to the matching driver */
1123 if (pdev->driver_override)
1124 return !strcmp(pdev->driver_override, drv->name);
1126 /* Attempt an OF style match first */
1127 if (of_driver_match_device(dev, drv))
1130 /* Then try ACPI style match */
1131 if (acpi_driver_match_device(dev, drv))
1134 /* Then try to match against the id table */
1136 return platform_match_id(pdrv->id_table, pdev) != NULL;
1138 /* fall-back to driver name match */
1139 return (strcmp(pdev->name, drv->name) == 0);
1142 #ifdef CONFIG_PM_SLEEP
1144 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1146 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1147 struct platform_device *pdev = to_platform_device(dev);
1150 if (dev->driver && pdrv->suspend)
1151 ret = pdrv->suspend(pdev, mesg);
1156 static int platform_legacy_resume(struct device *dev)
1158 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1159 struct platform_device *pdev = to_platform_device(dev);
1162 if (dev->driver && pdrv->resume)
1163 ret = pdrv->resume(pdev);
1168 #endif /* CONFIG_PM_SLEEP */
1170 #ifdef CONFIG_SUSPEND
1172 int platform_pm_suspend(struct device *dev)
1174 struct device_driver *drv = dev->driver;
1181 if (drv->pm->suspend)
1182 ret = drv->pm->suspend(dev);
1184 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1190 int platform_pm_resume(struct device *dev)
1192 struct device_driver *drv = dev->driver;
1199 if (drv->pm->resume)
1200 ret = drv->pm->resume(dev);
1202 ret = platform_legacy_resume(dev);
1208 #endif /* CONFIG_SUSPEND */
1210 #ifdef CONFIG_HIBERNATE_CALLBACKS
1212 int platform_pm_freeze(struct device *dev)
1214 struct device_driver *drv = dev->driver;
1221 if (drv->pm->freeze)
1222 ret = drv->pm->freeze(dev);
1224 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1230 int platform_pm_thaw(struct device *dev)
1232 struct device_driver *drv = dev->driver;
1240 ret = drv->pm->thaw(dev);
1242 ret = platform_legacy_resume(dev);
1248 int platform_pm_poweroff(struct device *dev)
1250 struct device_driver *drv = dev->driver;
1257 if (drv->pm->poweroff)
1258 ret = drv->pm->poweroff(dev);
1260 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1266 int platform_pm_restore(struct device *dev)
1268 struct device_driver *drv = dev->driver;
1275 if (drv->pm->restore)
1276 ret = drv->pm->restore(dev);
1278 ret = platform_legacy_resume(dev);
1284 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1286 int platform_dma_configure(struct device *dev)
1288 enum dev_dma_attr attr;
1292 ret = of_dma_configure(dev, dev->of_node, true);
1293 } else if (has_acpi_companion(dev)) {
1294 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1295 ret = acpi_dma_configure(dev, attr);
1301 static const struct dev_pm_ops platform_dev_pm_ops = {
1302 .runtime_suspend = pm_generic_runtime_suspend,
1303 .runtime_resume = pm_generic_runtime_resume,
1304 USE_PLATFORM_PM_SLEEP_OPS
1307 struct bus_type platform_bus_type = {
1309 .dev_groups = platform_dev_groups,
1310 .match = platform_match,
1311 .uevent = platform_uevent,
1312 .dma_configure = platform_dma_configure,
1313 .pm = &platform_dev_pm_ops,
1315 EXPORT_SYMBOL_GPL(platform_bus_type);
1317 static inline int __platform_match(struct device *dev, const void *drv)
1319 return platform_match(dev, (struct device_driver *)drv);
1323 * platform_find_device_by_driver - Find a platform device with a given
1325 * @start: The device to start the search from.
1326 * @drv: The device driver to look for.
1328 struct device *platform_find_device_by_driver(struct device *start,
1329 const struct device_driver *drv)
1331 return bus_find_device(&platform_bus_type, start, drv,
1334 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1336 void __weak __init early_platform_cleanup(void) { }
1338 int __init platform_bus_init(void)
1342 early_platform_cleanup();
1344 error = device_register(&platform_bus);
1346 put_device(&platform_bus);
1349 error = bus_register(&platform_bus_type);
1351 device_unregister(&platform_bus);
1352 of_platform_register_reconfig_notifier();