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: non-zero IRQ number on success, negative error number on failure.
157 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 ret = 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);
198 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
207 * For the index 0 interrupt, allow falling back to GpioInt
208 * resources. While a device could have both Interrupt and GpioInt
209 * resources, making this fallback ambiguous, in many common cases
210 * the device will only expose one IRQ, and this fallback
211 * allows a common code path across either kind of resource.
213 if (num == 0 && has_acpi_companion(&dev->dev)) {
214 ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
215 /* Our callers expect -ENXIO for missing IRQs. */
216 if (ret >= 0 || ret == -EPROBE_DEFER)
223 WARN(ret == 0, "0 is an invalid IRQ number\n");
226 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
229 * platform_get_irq - get an IRQ for a device
230 * @dev: platform device
231 * @num: IRQ number index
233 * Gets an IRQ for a platform device and prints an error message if finding the
234 * IRQ fails. Device drivers should check the return value for errors so as to
235 * not pass a negative integer value to the request_irq() APIs.
238 * int irq = platform_get_irq(pdev, 0);
242 * Return: non-zero IRQ number on success, negative error number on failure.
244 int platform_get_irq(struct platform_device *dev, unsigned int num)
248 ret = platform_get_irq_optional(dev, num);
249 if (ret < 0 && ret != -EPROBE_DEFER)
250 dev_err(&dev->dev, "IRQ index %u not found\n", num);
254 EXPORT_SYMBOL_GPL(platform_get_irq);
257 * platform_irq_count - Count the number of IRQs a platform device uses
258 * @dev: platform device
260 * Return: Number of IRQs a platform device uses or EPROBE_DEFER
262 int platform_irq_count(struct platform_device *dev)
266 while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
269 if (ret == -EPROBE_DEFER)
274 EXPORT_SYMBOL_GPL(platform_irq_count);
277 * platform_get_resource_byname - get a resource for a device by name
278 * @dev: platform device
279 * @type: resource type
280 * @name: resource name
282 struct resource *platform_get_resource_byname(struct platform_device *dev,
288 for (i = 0; i < dev->num_resources; i++) {
289 struct resource *r = &dev->resource[i];
291 if (unlikely(!r->name))
294 if (type == resource_type(r) && !strcmp(r->name, name))
299 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
301 static int __platform_get_irq_byname(struct platform_device *dev,
307 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
308 ret = of_irq_get_byname(dev->dev.of_node, name);
309 if (ret > 0 || ret == -EPROBE_DEFER)
313 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
315 WARN(r->start == 0, "0 is an invalid IRQ number\n");
323 * platform_get_irq_byname - get an IRQ for a device by name
324 * @dev: platform device
327 * Get an IRQ like platform_get_irq(), but then by name rather then by index.
329 * Return: non-zero IRQ number on success, negative error number on failure.
331 int platform_get_irq_byname(struct platform_device *dev, const char *name)
335 ret = __platform_get_irq_byname(dev, name);
336 if (ret < 0 && ret != -EPROBE_DEFER)
337 dev_err(&dev->dev, "IRQ %s not found\n", name);
341 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
344 * platform_get_irq_byname_optional - get an optional IRQ for a device by name
345 * @dev: platform device
348 * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
349 * does not print an error message if an IRQ can not be obtained.
351 * Return: non-zero IRQ number on success, negative error number on failure.
353 int platform_get_irq_byname_optional(struct platform_device *dev,
356 return __platform_get_irq_byname(dev, name);
358 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
361 * platform_add_devices - add a numbers of platform devices
362 * @devs: array of platform devices to add
363 * @num: number of platform devices in array
365 int platform_add_devices(struct platform_device **devs, int num)
369 for (i = 0; i < num; i++) {
370 ret = platform_device_register(devs[i]);
373 platform_device_unregister(devs[i]);
380 EXPORT_SYMBOL_GPL(platform_add_devices);
382 struct platform_object {
383 struct platform_device pdev;
388 * Set up default DMA mask for platform devices if the they weren't
389 * previously set by the architecture / DT.
391 static void setup_pdev_dma_masks(struct platform_device *pdev)
393 if (!pdev->dev.coherent_dma_mask)
394 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
395 if (!pdev->dev.dma_mask) {
396 pdev->platform_dma_mask = DMA_BIT_MASK(32);
397 pdev->dev.dma_mask = &pdev->platform_dma_mask;
402 * platform_device_put - destroy a platform device
403 * @pdev: platform device to free
405 * Free all memory associated with a platform device. This function must
406 * _only_ be externally called in error cases. All other usage is a bug.
408 void platform_device_put(struct platform_device *pdev)
410 if (!IS_ERR_OR_NULL(pdev))
411 put_device(&pdev->dev);
413 EXPORT_SYMBOL_GPL(platform_device_put);
415 static void platform_device_release(struct device *dev)
417 struct platform_object *pa = container_of(dev, struct platform_object,
420 of_device_node_put(&pa->pdev.dev);
421 kfree(pa->pdev.dev.platform_data);
422 kfree(pa->pdev.mfd_cell);
423 kfree(pa->pdev.resource);
424 kfree(pa->pdev.driver_override);
429 * platform_device_alloc - create a platform device
430 * @name: base name of the device we're adding
433 * Create a platform device object which can have other objects attached
434 * to it, and which will have attached objects freed when it is released.
436 struct platform_device *platform_device_alloc(const char *name, int id)
438 struct platform_object *pa;
440 pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
442 strcpy(pa->name, name);
443 pa->pdev.name = pa->name;
445 device_initialize(&pa->pdev.dev);
446 pa->pdev.dev.release = platform_device_release;
447 setup_pdev_dma_masks(&pa->pdev);
450 return pa ? &pa->pdev : NULL;
452 EXPORT_SYMBOL_GPL(platform_device_alloc);
455 * platform_device_add_resources - add resources to a platform device
456 * @pdev: platform device allocated by platform_device_alloc to add resources to
457 * @res: set of resources that needs to be allocated for the device
458 * @num: number of resources
460 * Add a copy of the resources to the platform device. The memory
461 * associated with the resources will be freed when the platform device is
464 int platform_device_add_resources(struct platform_device *pdev,
465 const struct resource *res, unsigned int num)
467 struct resource *r = NULL;
470 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
475 kfree(pdev->resource);
477 pdev->num_resources = num;
480 EXPORT_SYMBOL_GPL(platform_device_add_resources);
483 * platform_device_add_data - add platform-specific data to a platform device
484 * @pdev: platform device allocated by platform_device_alloc to add resources to
485 * @data: platform specific data for this platform device
486 * @size: size of platform specific data
488 * Add a copy of platform specific data to the platform device's
489 * platform_data pointer. The memory associated with the platform data
490 * will be freed when the platform device is released.
492 int platform_device_add_data(struct platform_device *pdev, const void *data,
498 d = kmemdup(data, size, GFP_KERNEL);
503 kfree(pdev->dev.platform_data);
504 pdev->dev.platform_data = d;
507 EXPORT_SYMBOL_GPL(platform_device_add_data);
510 * platform_device_add_properties - add built-in properties to a platform device
511 * @pdev: platform device to add properties to
512 * @properties: null terminated array of properties to add
514 * The function will take deep copy of @properties and attach the copy to the
515 * platform device. The memory associated with properties will be freed when the
516 * platform device is released.
518 int platform_device_add_properties(struct platform_device *pdev,
519 const struct property_entry *properties)
521 return device_add_properties(&pdev->dev, properties);
523 EXPORT_SYMBOL_GPL(platform_device_add_properties);
526 * platform_device_add - add a platform device to device hierarchy
527 * @pdev: platform device we're adding
529 * This is part 2 of platform_device_register(), though may be called
530 * separately _iff_ pdev was allocated by platform_device_alloc().
532 int platform_device_add(struct platform_device *pdev)
540 if (!pdev->dev.parent)
541 pdev->dev.parent = &platform_bus;
543 pdev->dev.bus = &platform_bus_type;
547 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
549 case PLATFORM_DEVID_NONE:
550 dev_set_name(&pdev->dev, "%s", pdev->name);
552 case PLATFORM_DEVID_AUTO:
554 * Automatically allocated device ID. We mark it as such so
555 * that we remember it must be freed, and we append a suffix
556 * to avoid namespace collision with explicit IDs.
558 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
562 pdev->id_auto = true;
563 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
567 for (i = 0; i < pdev->num_resources; i++) {
568 struct resource *p, *r = &pdev->resource[i];
571 r->name = dev_name(&pdev->dev);
575 if (resource_type(r) == IORESOURCE_MEM)
577 else if (resource_type(r) == IORESOURCE_IO)
578 p = &ioport_resource;
582 ret = insert_resource(p, r);
584 dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
590 pr_debug("Registering platform device '%s'. Parent at %s\n",
591 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
593 ret = device_add(&pdev->dev);
599 ida_simple_remove(&platform_devid_ida, pdev->id);
600 pdev->id = PLATFORM_DEVID_AUTO;
604 struct resource *r = &pdev->resource[i];
612 EXPORT_SYMBOL_GPL(platform_device_add);
615 * platform_device_del - remove a platform-level device
616 * @pdev: platform device we're removing
618 * Note that this function will also release all memory- and port-based
619 * resources owned by the device (@dev->resource). This function must
620 * _only_ be externally called in error cases. All other usage is a bug.
622 void platform_device_del(struct platform_device *pdev)
626 if (!IS_ERR_OR_NULL(pdev)) {
627 device_del(&pdev->dev);
630 ida_simple_remove(&platform_devid_ida, pdev->id);
631 pdev->id = PLATFORM_DEVID_AUTO;
634 for (i = 0; i < pdev->num_resources; i++) {
635 struct resource *r = &pdev->resource[i];
641 EXPORT_SYMBOL_GPL(platform_device_del);
644 * platform_device_register - add a platform-level device
645 * @pdev: platform device we're adding
647 int platform_device_register(struct platform_device *pdev)
649 device_initialize(&pdev->dev);
650 setup_pdev_dma_masks(pdev);
651 return platform_device_add(pdev);
653 EXPORT_SYMBOL_GPL(platform_device_register);
656 * platform_device_unregister - unregister a platform-level device
657 * @pdev: platform device we're unregistering
659 * Unregistration is done in 2 steps. First we release all resources
660 * and remove it from the subsystem, then we drop reference count by
661 * calling platform_device_put().
663 void platform_device_unregister(struct platform_device *pdev)
665 platform_device_del(pdev);
666 platform_device_put(pdev);
668 EXPORT_SYMBOL_GPL(platform_device_unregister);
671 * platform_device_register_full - add a platform-level device with
672 * resources and platform-specific data
674 * @pdevinfo: data used to create device
676 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
678 struct platform_device *platform_device_register_full(
679 const struct platform_device_info *pdevinfo)
682 struct platform_device *pdev;
684 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
686 return ERR_PTR(-ENOMEM);
688 pdev->dev.parent = pdevinfo->parent;
689 pdev->dev.fwnode = pdevinfo->fwnode;
690 pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
691 pdev->dev.of_node_reused = pdevinfo->of_node_reused;
693 if (pdevinfo->dma_mask) {
694 pdev->platform_dma_mask = pdevinfo->dma_mask;
695 pdev->dev.dma_mask = &pdev->platform_dma_mask;
696 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
699 ret = platform_device_add_resources(pdev,
700 pdevinfo->res, pdevinfo->num_res);
704 ret = platform_device_add_data(pdev,
705 pdevinfo->data, pdevinfo->size_data);
709 if (pdevinfo->properties) {
710 ret = platform_device_add_properties(pdev,
711 pdevinfo->properties);
716 ret = platform_device_add(pdev);
719 ACPI_COMPANION_SET(&pdev->dev, NULL);
720 platform_device_put(pdev);
726 EXPORT_SYMBOL_GPL(platform_device_register_full);
728 static int platform_drv_probe(struct device *_dev)
730 struct platform_driver *drv = to_platform_driver(_dev->driver);
731 struct platform_device *dev = to_platform_device(_dev);
734 ret = of_clk_set_defaults(_dev->of_node, false);
738 ret = dev_pm_domain_attach(_dev, true);
743 ret = drv->probe(dev);
745 dev_pm_domain_detach(_dev, true);
749 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
750 dev_warn(_dev, "probe deferral not supported\n");
757 static int platform_drv_probe_fail(struct device *_dev)
762 static int platform_drv_remove(struct device *_dev)
764 struct platform_driver *drv = to_platform_driver(_dev->driver);
765 struct platform_device *dev = to_platform_device(_dev);
769 ret = drv->remove(dev);
770 dev_pm_domain_detach(_dev, true);
775 static void platform_drv_shutdown(struct device *_dev)
777 struct platform_driver *drv = to_platform_driver(_dev->driver);
778 struct platform_device *dev = to_platform_device(_dev);
785 * __platform_driver_register - register a driver for platform-level devices
786 * @drv: platform driver structure
787 * @owner: owning module/driver
789 int __platform_driver_register(struct platform_driver *drv,
790 struct module *owner)
792 drv->driver.owner = owner;
793 drv->driver.bus = &platform_bus_type;
794 drv->driver.probe = platform_drv_probe;
795 drv->driver.remove = platform_drv_remove;
796 drv->driver.shutdown = platform_drv_shutdown;
798 return driver_register(&drv->driver);
800 EXPORT_SYMBOL_GPL(__platform_driver_register);
803 * platform_driver_unregister - unregister a driver for platform-level devices
804 * @drv: platform driver structure
806 void platform_driver_unregister(struct platform_driver *drv)
808 driver_unregister(&drv->driver);
810 EXPORT_SYMBOL_GPL(platform_driver_unregister);
813 * __platform_driver_probe - register driver for non-hotpluggable device
814 * @drv: platform driver structure
815 * @probe: the driver probe routine, probably from an __init section
816 * @module: module which will be the owner of the driver
818 * Use this instead of platform_driver_register() when you know the device
819 * is not hotpluggable and has already been registered, and you want to
820 * remove its run-once probe() infrastructure from memory after the driver
821 * has bound to the device.
823 * One typical use for this would be with drivers for controllers integrated
824 * into system-on-chip processors, where the controller devices have been
825 * configured as part of board setup.
827 * Note that this is incompatible with deferred probing.
829 * Returns zero if the driver registered and bound to a device, else returns
830 * a negative error code and with the driver not registered.
832 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
833 int (*probe)(struct platform_device *), struct module *module)
837 if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
838 pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
839 drv->driver.name, __func__);
844 * We have to run our probes synchronously because we check if
845 * we find any devices to bind to and exit with error if there
848 drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
851 * Prevent driver from requesting probe deferral to avoid further
852 * futile probe attempts.
854 drv->prevent_deferred_probe = true;
856 /* make sure driver won't have bind/unbind attributes */
857 drv->driver.suppress_bind_attrs = true;
859 /* temporary section violation during probe() */
861 retval = code = __platform_driver_register(drv, module);
864 * Fixup that section violation, being paranoid about code scanning
865 * the list of drivers in order to probe new devices. Check to see
866 * if the probe was successful, and make sure any forced probes of
869 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
871 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
873 drv->driver.probe = platform_drv_probe_fail;
874 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
877 platform_driver_unregister(drv);
880 EXPORT_SYMBOL_GPL(__platform_driver_probe);
883 * __platform_create_bundle - register driver and create corresponding device
884 * @driver: platform driver structure
885 * @probe: the driver probe routine, probably from an __init section
886 * @res: set of resources that needs to be allocated for the device
887 * @n_res: number of resources
888 * @data: platform specific data for this platform device
889 * @size: size of platform specific data
890 * @module: module which will be the owner of the driver
892 * Use this in legacy-style modules that probe hardware directly and
893 * register a single platform device and corresponding platform driver.
895 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
897 struct platform_device * __init_or_module __platform_create_bundle(
898 struct platform_driver *driver,
899 int (*probe)(struct platform_device *),
900 struct resource *res, unsigned int n_res,
901 const void *data, size_t size, struct module *module)
903 struct platform_device *pdev;
906 pdev = platform_device_alloc(driver->driver.name, -1);
912 error = platform_device_add_resources(pdev, res, n_res);
916 error = platform_device_add_data(pdev, data, size);
920 error = platform_device_add(pdev);
924 error = __platform_driver_probe(driver, probe, module);
931 platform_device_del(pdev);
933 platform_device_put(pdev);
935 return ERR_PTR(error);
937 EXPORT_SYMBOL_GPL(__platform_create_bundle);
940 * __platform_register_drivers - register an array of platform drivers
941 * @drivers: an array of drivers to register
942 * @count: the number of drivers to register
943 * @owner: module owning the drivers
945 * Registers platform drivers specified by an array. On failure to register a
946 * driver, all previously registered drivers will be unregistered. Callers of
947 * this API should use platform_unregister_drivers() to unregister drivers in
950 * Returns: 0 on success or a negative error code on failure.
952 int __platform_register_drivers(struct platform_driver * const *drivers,
953 unsigned int count, struct module *owner)
958 for (i = 0; i < count; i++) {
959 pr_debug("registering platform driver %ps\n", drivers[i]);
961 err = __platform_driver_register(drivers[i], owner);
963 pr_err("failed to register platform driver %ps: %d\n",
973 pr_debug("unregistering platform driver %ps\n", drivers[i]);
974 platform_driver_unregister(drivers[i]);
979 EXPORT_SYMBOL_GPL(__platform_register_drivers);
982 * platform_unregister_drivers - unregister an array of platform drivers
983 * @drivers: an array of drivers to unregister
984 * @count: the number of drivers to unregister
986 * Unegisters platform drivers specified by an array. This is typically used
987 * to complement an earlier call to platform_register_drivers(). Drivers are
988 * unregistered in the reverse order in which they were registered.
990 void platform_unregister_drivers(struct platform_driver * const *drivers,
994 pr_debug("unregistering platform driver %ps\n", drivers[count]);
995 platform_driver_unregister(drivers[count]);
998 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1000 /* modalias support enables more hands-off userspace setup:
1001 * (a) environment variable lets new-style hotplug events work once system is
1002 * fully running: "modprobe $MODALIAS"
1003 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
1004 * mishandled before system is fully running: "modprobe $(cat modalias)"
1006 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
1009 struct platform_device *pdev = to_platform_device(dev);
1012 len = of_device_modalias(dev, buf, PAGE_SIZE);
1016 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
1020 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
1022 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
1024 static DEVICE_ATTR_RO(modalias);
1026 static ssize_t driver_override_store(struct device *dev,
1027 struct device_attribute *attr,
1028 const char *buf, size_t count)
1030 struct platform_device *pdev = to_platform_device(dev);
1031 char *driver_override, *old, *cp;
1033 /* We need to keep extra room for a newline */
1034 if (count >= (PAGE_SIZE - 1))
1037 driver_override = kstrndup(buf, count, GFP_KERNEL);
1038 if (!driver_override)
1041 cp = strchr(driver_override, '\n');
1046 old = pdev->driver_override;
1047 if (strlen(driver_override)) {
1048 pdev->driver_override = driver_override;
1050 kfree(driver_override);
1051 pdev->driver_override = NULL;
1060 static ssize_t driver_override_show(struct device *dev,
1061 struct device_attribute *attr, char *buf)
1063 struct platform_device *pdev = to_platform_device(dev);
1067 len = sprintf(buf, "%s\n", pdev->driver_override);
1071 static DEVICE_ATTR_RW(driver_override);
1074 static struct attribute *platform_dev_attrs[] = {
1075 &dev_attr_modalias.attr,
1076 &dev_attr_driver_override.attr,
1079 ATTRIBUTE_GROUPS(platform_dev);
1081 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1083 struct platform_device *pdev = to_platform_device(dev);
1086 /* Some devices have extra OF data and an OF-style MODALIAS */
1087 rc = of_device_uevent_modalias(dev, env);
1091 rc = acpi_device_uevent_modalias(dev, env);
1095 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1100 static const struct platform_device_id *platform_match_id(
1101 const struct platform_device_id *id,
1102 struct platform_device *pdev)
1104 while (id->name[0]) {
1105 if (strcmp(pdev->name, id->name) == 0) {
1106 pdev->id_entry = id;
1115 * platform_match - bind platform device to platform driver.
1119 * Platform device IDs are assumed to be encoded like this:
1120 * "<name><instance>", where <name> is a short description of the type of
1121 * device, like "pci" or "floppy", and <instance> is the enumerated
1122 * instance of the device, like '0' or '42'. Driver IDs are simply
1123 * "<name>". So, extract the <name> from the platform_device structure,
1124 * and compare it against the name of the driver. Return whether they match
1127 static int platform_match(struct device *dev, struct device_driver *drv)
1129 struct platform_device *pdev = to_platform_device(dev);
1130 struct platform_driver *pdrv = to_platform_driver(drv);
1132 /* When driver_override is set, only bind to the matching driver */
1133 if (pdev->driver_override)
1134 return !strcmp(pdev->driver_override, drv->name);
1136 /* Attempt an OF style match first */
1137 if (of_driver_match_device(dev, drv))
1140 /* Then try ACPI style match */
1141 if (acpi_driver_match_device(dev, drv))
1144 /* Then try to match against the id table */
1146 return platform_match_id(pdrv->id_table, pdev) != NULL;
1148 /* fall-back to driver name match */
1149 return (strcmp(pdev->name, drv->name) == 0);
1152 #ifdef CONFIG_PM_SLEEP
1154 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1156 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1157 struct platform_device *pdev = to_platform_device(dev);
1160 if (dev->driver && pdrv->suspend)
1161 ret = pdrv->suspend(pdev, mesg);
1166 static int platform_legacy_resume(struct device *dev)
1168 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1169 struct platform_device *pdev = to_platform_device(dev);
1172 if (dev->driver && pdrv->resume)
1173 ret = pdrv->resume(pdev);
1178 #endif /* CONFIG_PM_SLEEP */
1180 #ifdef CONFIG_SUSPEND
1182 int platform_pm_suspend(struct device *dev)
1184 struct device_driver *drv = dev->driver;
1191 if (drv->pm->suspend)
1192 ret = drv->pm->suspend(dev);
1194 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1200 int platform_pm_resume(struct device *dev)
1202 struct device_driver *drv = dev->driver;
1209 if (drv->pm->resume)
1210 ret = drv->pm->resume(dev);
1212 ret = platform_legacy_resume(dev);
1218 #endif /* CONFIG_SUSPEND */
1220 #ifdef CONFIG_HIBERNATE_CALLBACKS
1222 int platform_pm_freeze(struct device *dev)
1224 struct device_driver *drv = dev->driver;
1231 if (drv->pm->freeze)
1232 ret = drv->pm->freeze(dev);
1234 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1240 int platform_pm_thaw(struct device *dev)
1242 struct device_driver *drv = dev->driver;
1250 ret = drv->pm->thaw(dev);
1252 ret = platform_legacy_resume(dev);
1258 int platform_pm_poweroff(struct device *dev)
1260 struct device_driver *drv = dev->driver;
1267 if (drv->pm->poweroff)
1268 ret = drv->pm->poweroff(dev);
1270 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1276 int platform_pm_restore(struct device *dev)
1278 struct device_driver *drv = dev->driver;
1285 if (drv->pm->restore)
1286 ret = drv->pm->restore(dev);
1288 ret = platform_legacy_resume(dev);
1294 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1296 int platform_dma_configure(struct device *dev)
1298 enum dev_dma_attr attr;
1302 ret = of_dma_configure(dev, dev->of_node, true);
1303 } else if (has_acpi_companion(dev)) {
1304 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1305 ret = acpi_dma_configure(dev, attr);
1311 static const struct dev_pm_ops platform_dev_pm_ops = {
1312 .runtime_suspend = pm_generic_runtime_suspend,
1313 .runtime_resume = pm_generic_runtime_resume,
1314 USE_PLATFORM_PM_SLEEP_OPS
1317 struct bus_type platform_bus_type = {
1319 .dev_groups = platform_dev_groups,
1320 .match = platform_match,
1321 .uevent = platform_uevent,
1322 .dma_configure = platform_dma_configure,
1323 .pm = &platform_dev_pm_ops,
1325 EXPORT_SYMBOL_GPL(platform_bus_type);
1327 static inline int __platform_match(struct device *dev, const void *drv)
1329 return platform_match(dev, (struct device_driver *)drv);
1333 * platform_find_device_by_driver - Find a platform device with a given
1335 * @start: The device to start the search from.
1336 * @drv: The device driver to look for.
1338 struct device *platform_find_device_by_driver(struct device *start,
1339 const struct device_driver *drv)
1341 return bus_find_device(&platform_bus_type, start, drv,
1344 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1346 void __weak __init early_platform_cleanup(void) { }
1348 int __init platform_bus_init(void)
1352 early_platform_cleanup();
1354 error = device_register(&platform_bus);
1356 put_device(&platform_bus);
1359 error = bus_register(&platform_bus_type);
1361 device_unregister(&platform_bus);
1362 of_platform_register_reconfig_notifier();