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>
32 #include "power/power.h"
34 /* For automatically allocated device IDs */
35 static DEFINE_IDA(platform_devid_ida);
37 struct device platform_bus = {
38 .init_name = "platform",
40 EXPORT_SYMBOL_GPL(platform_bus);
43 * platform_get_resource - get a resource for a device
44 * @dev: platform device
45 * @type: resource type
46 * @num: resource index
48 struct resource *platform_get_resource(struct platform_device *dev,
49 unsigned int type, unsigned int num)
53 for (i = 0; i < dev->num_resources; i++) {
54 struct resource *r = &dev->resource[i];
56 if (type == resource_type(r) && num-- == 0)
61 EXPORT_SYMBOL_GPL(platform_get_resource);
63 #ifdef CONFIG_HAS_IOMEM
65 * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
68 * @pdev: platform device to use both for memory resource lookup as well as
70 * @index: resource index
72 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
77 res = platform_get_resource(pdev, IORESOURCE_MEM, index);
78 return devm_ioremap_resource(&pdev->dev, res);
80 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
83 * devm_platform_ioremap_resource_wc - write-combined variant of
84 * devm_platform_ioremap_resource()
86 * @pdev: platform device to use both for memory resource lookup as well as
88 * @index: resource index
90 void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
95 res = platform_get_resource(pdev, IORESOURCE_MEM, index);
96 return devm_ioremap_resource_wc(&pdev->dev, res);
100 * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
101 * a platform device, retrieve the
104 * @pdev: platform device to use both for memory resource lookup as well as
105 * resource management
106 * @name: name of the resource
109 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
112 struct resource *res;
114 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
115 return devm_ioremap_resource(&pdev->dev, res);
117 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
118 #endif /* CONFIG_HAS_IOMEM */
121 * platform_get_irq_optional - get an optional IRQ for a device
122 * @dev: platform device
123 * @num: IRQ number index
125 * Gets an IRQ for a platform device. Device drivers should check the return
126 * value for errors so as to not pass a negative integer value to the
127 * request_irq() APIs. This is the same as platform_get_irq(), except that it
128 * does not print an error message if an IRQ can not be obtained.
131 * int irq = platform_get_irq_optional(pdev, 0);
135 * Return: IRQ number on success, negative error number on failure.
137 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
140 /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
141 if (!dev || num >= dev->archdata.num_irqs)
143 return dev->archdata.irqs[num];
148 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
149 ret = of_irq_get(dev->dev.of_node, num);
150 if (ret > 0 || ret == -EPROBE_DEFER)
154 r = platform_get_resource(dev, IORESOURCE_IRQ, num);
155 if (has_acpi_companion(&dev->dev)) {
156 if (r && r->flags & IORESOURCE_DISABLED) {
157 ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
164 * The resources may pass trigger flags to the irqs that need
165 * to be set up. It so happens that the trigger flags for
166 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
169 if (r && r->flags & IORESOURCE_BITS) {
170 struct irq_data *irqd;
172 irqd = irq_get_irq_data(r->start);
175 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
182 * For the index 0 interrupt, allow falling back to GpioInt
183 * resources. While a device could have both Interrupt and GpioInt
184 * resources, making this fallback ambiguous, in many common cases
185 * the device will only expose one IRQ, and this fallback
186 * allows a common code path across either kind of resource.
188 if (num == 0 && has_acpi_companion(&dev->dev)) {
189 ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
190 /* Our callers expect -ENXIO for missing IRQs. */
191 if (ret >= 0 || ret == -EPROBE_DEFER)
198 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
201 * platform_get_irq - get an IRQ for a device
202 * @dev: platform device
203 * @num: IRQ number index
205 * Gets an IRQ for a platform device and prints an error message if finding the
206 * IRQ fails. Device drivers should check the return value for errors so as to
207 * not pass a negative integer value to the request_irq() APIs.
210 * int irq = platform_get_irq(pdev, 0);
214 * Return: IRQ number on success, negative error number on failure.
216 int platform_get_irq(struct platform_device *dev, unsigned int num)
220 ret = platform_get_irq_optional(dev, num);
221 if (ret < 0 && ret != -EPROBE_DEFER)
222 dev_err(&dev->dev, "IRQ index %u not found\n", num);
226 EXPORT_SYMBOL_GPL(platform_get_irq);
229 * platform_irq_count - Count the number of IRQs a platform device uses
230 * @dev: platform device
232 * Return: Number of IRQs a platform device uses or EPROBE_DEFER
234 int platform_irq_count(struct platform_device *dev)
238 while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
241 if (ret == -EPROBE_DEFER)
246 EXPORT_SYMBOL_GPL(platform_irq_count);
249 * platform_get_resource_byname - get a resource for a device by name
250 * @dev: platform device
251 * @type: resource type
252 * @name: resource name
254 struct resource *platform_get_resource_byname(struct platform_device *dev,
260 for (i = 0; i < dev->num_resources; i++) {
261 struct resource *r = &dev->resource[i];
263 if (unlikely(!r->name))
266 if (type == resource_type(r) && !strcmp(r->name, name))
271 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
273 static int __platform_get_irq_byname(struct platform_device *dev,
279 if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
280 ret = of_irq_get_byname(dev->dev.of_node, name);
281 if (ret > 0 || ret == -EPROBE_DEFER)
285 r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
293 * platform_get_irq_byname - get an IRQ for a device by name
294 * @dev: platform device
297 * Get an IRQ like platform_get_irq(), but then by name rather then by index.
299 * Return: IRQ number on success, negative error number on failure.
301 int platform_get_irq_byname(struct platform_device *dev, const char *name)
305 ret = __platform_get_irq_byname(dev, name);
306 if (ret < 0 && ret != -EPROBE_DEFER)
307 dev_err(&dev->dev, "IRQ %s not found\n", name);
311 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
314 * platform_get_irq_byname_optional - get an optional IRQ for a device by name
315 * @dev: platform device
318 * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
319 * does not print an error message if an IRQ can not be obtained.
321 * Return: IRQ number on success, negative error number on failure.
323 int platform_get_irq_byname_optional(struct platform_device *dev,
326 return __platform_get_irq_byname(dev, name);
328 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
331 * platform_add_devices - add a numbers of platform devices
332 * @devs: array of platform devices to add
333 * @num: number of platform devices in array
335 int platform_add_devices(struct platform_device **devs, int num)
339 for (i = 0; i < num; i++) {
340 ret = platform_device_register(devs[i]);
343 platform_device_unregister(devs[i]);
350 EXPORT_SYMBOL_GPL(platform_add_devices);
352 struct platform_object {
353 struct platform_device pdev;
358 * Set up default DMA mask for platform devices if the they weren't
359 * previously set by the architecture / DT.
361 static void setup_pdev_dma_masks(struct platform_device *pdev)
363 if (!pdev->dev.coherent_dma_mask)
364 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
366 pdev->dma_mask = DMA_BIT_MASK(32);
367 if (!pdev->dev.dma_mask)
368 pdev->dev.dma_mask = &pdev->dma_mask;
372 * platform_device_put - destroy a platform device
373 * @pdev: platform device to free
375 * Free all memory associated with a platform device. This function must
376 * _only_ be externally called in error cases. All other usage is a bug.
378 void platform_device_put(struct platform_device *pdev)
380 if (!IS_ERR_OR_NULL(pdev))
381 put_device(&pdev->dev);
383 EXPORT_SYMBOL_GPL(platform_device_put);
385 static void platform_device_release(struct device *dev)
387 struct platform_object *pa = container_of(dev, struct platform_object,
390 of_device_node_put(&pa->pdev.dev);
391 kfree(pa->pdev.dev.platform_data);
392 kfree(pa->pdev.mfd_cell);
393 kfree(pa->pdev.resource);
394 kfree(pa->pdev.driver_override);
399 * platform_device_alloc - create a platform device
400 * @name: base name of the device we're adding
403 * Create a platform device object which can have other objects attached
404 * to it, and which will have attached objects freed when it is released.
406 struct platform_device *platform_device_alloc(const char *name, int id)
408 struct platform_object *pa;
410 pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
412 strcpy(pa->name, name);
413 pa->pdev.name = pa->name;
415 device_initialize(&pa->pdev.dev);
416 pa->pdev.dev.release = platform_device_release;
417 setup_pdev_dma_masks(&pa->pdev);
420 return pa ? &pa->pdev : NULL;
422 EXPORT_SYMBOL_GPL(platform_device_alloc);
425 * platform_device_add_resources - add resources to a platform device
426 * @pdev: platform device allocated by platform_device_alloc to add resources to
427 * @res: set of resources that needs to be allocated for the device
428 * @num: number of resources
430 * Add a copy of the resources to the platform device. The memory
431 * associated with the resources will be freed when the platform device is
434 int platform_device_add_resources(struct platform_device *pdev,
435 const struct resource *res, unsigned int num)
437 struct resource *r = NULL;
440 r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
445 kfree(pdev->resource);
447 pdev->num_resources = num;
450 EXPORT_SYMBOL_GPL(platform_device_add_resources);
453 * platform_device_add_data - add platform-specific data to a platform device
454 * @pdev: platform device allocated by platform_device_alloc to add resources to
455 * @data: platform specific data for this platform device
456 * @size: size of platform specific data
458 * Add a copy of platform specific data to the platform device's
459 * platform_data pointer. The memory associated with the platform data
460 * will be freed when the platform device is released.
462 int platform_device_add_data(struct platform_device *pdev, const void *data,
468 d = kmemdup(data, size, GFP_KERNEL);
473 kfree(pdev->dev.platform_data);
474 pdev->dev.platform_data = d;
477 EXPORT_SYMBOL_GPL(platform_device_add_data);
480 * platform_device_add_properties - add built-in properties to a platform device
481 * @pdev: platform device to add properties to
482 * @properties: null terminated array of properties to add
484 * The function will take deep copy of @properties and attach the copy to the
485 * platform device. The memory associated with properties will be freed when the
486 * platform device is released.
488 int platform_device_add_properties(struct platform_device *pdev,
489 const struct property_entry *properties)
491 return device_add_properties(&pdev->dev, properties);
493 EXPORT_SYMBOL_GPL(platform_device_add_properties);
496 * platform_device_add - add a platform device to device hierarchy
497 * @pdev: platform device we're adding
499 * This is part 2 of platform_device_register(), though may be called
500 * separately _iff_ pdev was allocated by platform_device_alloc().
502 int platform_device_add(struct platform_device *pdev)
509 if (!pdev->dev.parent)
510 pdev->dev.parent = &platform_bus;
512 pdev->dev.bus = &platform_bus_type;
516 dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
518 case PLATFORM_DEVID_NONE:
519 dev_set_name(&pdev->dev, "%s", pdev->name);
521 case PLATFORM_DEVID_AUTO:
523 * Automatically allocated device ID. We mark it as such so
524 * that we remember it must be freed, and we append a suffix
525 * to avoid namespace collision with explicit IDs.
527 ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
531 pdev->id_auto = true;
532 dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
536 for (i = 0; i < pdev->num_resources; i++) {
537 struct resource *p, *r = &pdev->resource[i];
540 r->name = dev_name(&pdev->dev);
544 if (resource_type(r) == IORESOURCE_MEM)
546 else if (resource_type(r) == IORESOURCE_IO)
547 p = &ioport_resource;
551 ret = insert_resource(p, r);
553 dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
559 pr_debug("Registering platform device '%s'. Parent at %s\n",
560 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
562 ret = device_add(&pdev->dev);
568 ida_simple_remove(&platform_devid_ida, pdev->id);
569 pdev->id = PLATFORM_DEVID_AUTO;
573 struct resource *r = &pdev->resource[i];
581 EXPORT_SYMBOL_GPL(platform_device_add);
584 * platform_device_del - remove a platform-level device
585 * @pdev: platform device we're removing
587 * Note that this function will also release all memory- and port-based
588 * resources owned by the device (@dev->resource). This function must
589 * _only_ be externally called in error cases. All other usage is a bug.
591 void platform_device_del(struct platform_device *pdev)
595 if (!IS_ERR_OR_NULL(pdev)) {
596 device_del(&pdev->dev);
599 ida_simple_remove(&platform_devid_ida, pdev->id);
600 pdev->id = PLATFORM_DEVID_AUTO;
603 for (i = 0; i < pdev->num_resources; i++) {
604 struct resource *r = &pdev->resource[i];
610 EXPORT_SYMBOL_GPL(platform_device_del);
613 * platform_device_register - add a platform-level device
614 * @pdev: platform device we're adding
616 int platform_device_register(struct platform_device *pdev)
618 device_initialize(&pdev->dev);
619 setup_pdev_dma_masks(pdev);
620 return platform_device_add(pdev);
622 EXPORT_SYMBOL_GPL(platform_device_register);
625 * platform_device_unregister - unregister a platform-level device
626 * @pdev: platform device we're unregistering
628 * Unregistration is done in 2 steps. First we release all resources
629 * and remove it from the subsystem, then we drop reference count by
630 * calling platform_device_put().
632 void platform_device_unregister(struct platform_device *pdev)
634 platform_device_del(pdev);
635 platform_device_put(pdev);
637 EXPORT_SYMBOL_GPL(platform_device_unregister);
640 * platform_device_register_full - add a platform-level device with
641 * resources and platform-specific data
643 * @pdevinfo: data used to create device
645 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
647 struct platform_device *platform_device_register_full(
648 const struct platform_device_info *pdevinfo)
651 struct platform_device *pdev;
653 pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
655 return ERR_PTR(-ENOMEM);
657 pdev->dev.parent = pdevinfo->parent;
658 pdev->dev.fwnode = pdevinfo->fwnode;
659 pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
660 pdev->dev.of_node_reused = pdevinfo->of_node_reused;
662 if (pdevinfo->dma_mask) {
664 * This memory isn't freed when the device is put,
665 * I don't have a nice idea for that though. Conceptually
666 * dma_mask in struct device should not be a pointer.
667 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
670 kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
671 if (!pdev->dev.dma_mask)
674 kmemleak_ignore(pdev->dev.dma_mask);
676 *pdev->dev.dma_mask = pdevinfo->dma_mask;
677 pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
680 ret = platform_device_add_resources(pdev,
681 pdevinfo->res, pdevinfo->num_res);
685 ret = platform_device_add_data(pdev,
686 pdevinfo->data, pdevinfo->size_data);
690 if (pdevinfo->properties) {
691 ret = platform_device_add_properties(pdev,
692 pdevinfo->properties);
697 ret = platform_device_add(pdev);
700 ACPI_COMPANION_SET(&pdev->dev, NULL);
701 kfree(pdev->dev.dma_mask);
702 platform_device_put(pdev);
708 EXPORT_SYMBOL_GPL(platform_device_register_full);
710 static int platform_drv_probe(struct device *_dev)
712 struct platform_driver *drv = to_platform_driver(_dev->driver);
713 struct platform_device *dev = to_platform_device(_dev);
716 ret = of_clk_set_defaults(_dev->of_node, false);
720 ret = dev_pm_domain_attach(_dev, true);
725 ret = drv->probe(dev);
727 dev_pm_domain_detach(_dev, true);
731 if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
732 dev_warn(_dev, "probe deferral not supported\n");
739 static int platform_drv_probe_fail(struct device *_dev)
744 static int platform_drv_remove(struct device *_dev)
746 struct platform_driver *drv = to_platform_driver(_dev->driver);
747 struct platform_device *dev = to_platform_device(_dev);
751 ret = drv->remove(dev);
752 dev_pm_domain_detach(_dev, true);
757 static void platform_drv_shutdown(struct device *_dev)
759 struct platform_driver *drv = to_platform_driver(_dev->driver);
760 struct platform_device *dev = to_platform_device(_dev);
767 * __platform_driver_register - register a driver for platform-level devices
768 * @drv: platform driver structure
769 * @owner: owning module/driver
771 int __platform_driver_register(struct platform_driver *drv,
772 struct module *owner)
774 drv->driver.owner = owner;
775 drv->driver.bus = &platform_bus_type;
776 drv->driver.probe = platform_drv_probe;
777 drv->driver.remove = platform_drv_remove;
778 drv->driver.shutdown = platform_drv_shutdown;
780 return driver_register(&drv->driver);
782 EXPORT_SYMBOL_GPL(__platform_driver_register);
785 * platform_driver_unregister - unregister a driver for platform-level devices
786 * @drv: platform driver structure
788 void platform_driver_unregister(struct platform_driver *drv)
790 driver_unregister(&drv->driver);
792 EXPORT_SYMBOL_GPL(platform_driver_unregister);
795 * __platform_driver_probe - register driver for non-hotpluggable device
796 * @drv: platform driver structure
797 * @probe: the driver probe routine, probably from an __init section
798 * @module: module which will be the owner of the driver
800 * Use this instead of platform_driver_register() when you know the device
801 * is not hotpluggable and has already been registered, and you want to
802 * remove its run-once probe() infrastructure from memory after the driver
803 * has bound to the device.
805 * One typical use for this would be with drivers for controllers integrated
806 * into system-on-chip processors, where the controller devices have been
807 * configured as part of board setup.
809 * Note that this is incompatible with deferred probing.
811 * Returns zero if the driver registered and bound to a device, else returns
812 * a negative error code and with the driver not registered.
814 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
815 int (*probe)(struct platform_device *), struct module *module)
819 if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
820 pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
821 drv->driver.name, __func__);
826 * We have to run our probes synchronously because we check if
827 * we find any devices to bind to and exit with error if there
830 drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
833 * Prevent driver from requesting probe deferral to avoid further
834 * futile probe attempts.
836 drv->prevent_deferred_probe = true;
838 /* make sure driver won't have bind/unbind attributes */
839 drv->driver.suppress_bind_attrs = true;
841 /* temporary section violation during probe() */
843 retval = code = __platform_driver_register(drv, module);
846 * Fixup that section violation, being paranoid about code scanning
847 * the list of drivers in order to probe new devices. Check to see
848 * if the probe was successful, and make sure any forced probes of
851 spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
853 if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
855 drv->driver.probe = platform_drv_probe_fail;
856 spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
859 platform_driver_unregister(drv);
862 EXPORT_SYMBOL_GPL(__platform_driver_probe);
865 * __platform_create_bundle - register driver and create corresponding device
866 * @driver: platform driver structure
867 * @probe: the driver probe routine, probably from an __init section
868 * @res: set of resources that needs to be allocated for the device
869 * @n_res: number of resources
870 * @data: platform specific data for this platform device
871 * @size: size of platform specific data
872 * @module: module which will be the owner of the driver
874 * Use this in legacy-style modules that probe hardware directly and
875 * register a single platform device and corresponding platform driver.
877 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
879 struct platform_device * __init_or_module __platform_create_bundle(
880 struct platform_driver *driver,
881 int (*probe)(struct platform_device *),
882 struct resource *res, unsigned int n_res,
883 const void *data, size_t size, struct module *module)
885 struct platform_device *pdev;
888 pdev = platform_device_alloc(driver->driver.name, -1);
894 error = platform_device_add_resources(pdev, res, n_res);
898 error = platform_device_add_data(pdev, data, size);
902 error = platform_device_add(pdev);
906 error = __platform_driver_probe(driver, probe, module);
913 platform_device_del(pdev);
915 platform_device_put(pdev);
917 return ERR_PTR(error);
919 EXPORT_SYMBOL_GPL(__platform_create_bundle);
922 * __platform_register_drivers - register an array of platform drivers
923 * @drivers: an array of drivers to register
924 * @count: the number of drivers to register
925 * @owner: module owning the drivers
927 * Registers platform drivers specified by an array. On failure to register a
928 * driver, all previously registered drivers will be unregistered. Callers of
929 * this API should use platform_unregister_drivers() to unregister drivers in
932 * Returns: 0 on success or a negative error code on failure.
934 int __platform_register_drivers(struct platform_driver * const *drivers,
935 unsigned int count, struct module *owner)
940 for (i = 0; i < count; i++) {
941 pr_debug("registering platform driver %ps\n", drivers[i]);
943 err = __platform_driver_register(drivers[i], owner);
945 pr_err("failed to register platform driver %ps: %d\n",
955 pr_debug("unregistering platform driver %ps\n", drivers[i]);
956 platform_driver_unregister(drivers[i]);
961 EXPORT_SYMBOL_GPL(__platform_register_drivers);
964 * platform_unregister_drivers - unregister an array of platform drivers
965 * @drivers: an array of drivers to unregister
966 * @count: the number of drivers to unregister
968 * Unegisters platform drivers specified by an array. This is typically used
969 * to complement an earlier call to platform_register_drivers(). Drivers are
970 * unregistered in the reverse order in which they were registered.
972 void platform_unregister_drivers(struct platform_driver * const *drivers,
976 pr_debug("unregistering platform driver %ps\n", drivers[count]);
977 platform_driver_unregister(drivers[count]);
980 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
982 /* modalias support enables more hands-off userspace setup:
983 * (a) environment variable lets new-style hotplug events work once system is
984 * fully running: "modprobe $MODALIAS"
985 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
986 * mishandled before system is fully running: "modprobe $(cat modalias)"
988 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
991 struct platform_device *pdev = to_platform_device(dev);
994 len = of_device_modalias(dev, buf, PAGE_SIZE);
998 len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
1002 len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
1004 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
1006 static DEVICE_ATTR_RO(modalias);
1008 static ssize_t driver_override_store(struct device *dev,
1009 struct device_attribute *attr,
1010 const char *buf, size_t count)
1012 struct platform_device *pdev = to_platform_device(dev);
1013 char *driver_override, *old, *cp;
1015 /* We need to keep extra room for a newline */
1016 if (count >= (PAGE_SIZE - 1))
1019 driver_override = kstrndup(buf, count, GFP_KERNEL);
1020 if (!driver_override)
1023 cp = strchr(driver_override, '\n');
1028 old = pdev->driver_override;
1029 if (strlen(driver_override)) {
1030 pdev->driver_override = driver_override;
1032 kfree(driver_override);
1033 pdev->driver_override = NULL;
1042 static ssize_t driver_override_show(struct device *dev,
1043 struct device_attribute *attr, char *buf)
1045 struct platform_device *pdev = to_platform_device(dev);
1049 len = sprintf(buf, "%s\n", pdev->driver_override);
1053 static DEVICE_ATTR_RW(driver_override);
1056 static struct attribute *platform_dev_attrs[] = {
1057 &dev_attr_modalias.attr,
1058 &dev_attr_driver_override.attr,
1061 ATTRIBUTE_GROUPS(platform_dev);
1063 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1065 struct platform_device *pdev = to_platform_device(dev);
1068 /* Some devices have extra OF data and an OF-style MODALIAS */
1069 rc = of_device_uevent_modalias(dev, env);
1073 rc = acpi_device_uevent_modalias(dev, env);
1077 add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1082 static const struct platform_device_id *platform_match_id(
1083 const struct platform_device_id *id,
1084 struct platform_device *pdev)
1086 while (id->name[0]) {
1087 if (strcmp(pdev->name, id->name) == 0) {
1088 pdev->id_entry = id;
1097 * platform_match - bind platform device to platform driver.
1101 * Platform device IDs are assumed to be encoded like this:
1102 * "<name><instance>", where <name> is a short description of the type of
1103 * device, like "pci" or "floppy", and <instance> is the enumerated
1104 * instance of the device, like '0' or '42'. Driver IDs are simply
1105 * "<name>". So, extract the <name> from the platform_device structure,
1106 * and compare it against the name of the driver. Return whether they match
1109 static int platform_match(struct device *dev, struct device_driver *drv)
1111 struct platform_device *pdev = to_platform_device(dev);
1112 struct platform_driver *pdrv = to_platform_driver(drv);
1114 /* When driver_override is set, only bind to the matching driver */
1115 if (pdev->driver_override)
1116 return !strcmp(pdev->driver_override, drv->name);
1118 /* Attempt an OF style match first */
1119 if (of_driver_match_device(dev, drv))
1122 /* Then try ACPI style match */
1123 if (acpi_driver_match_device(dev, drv))
1126 /* Then try to match against the id table */
1128 return platform_match_id(pdrv->id_table, pdev) != NULL;
1130 /* fall-back to driver name match */
1131 return (strcmp(pdev->name, drv->name) == 0);
1134 #ifdef CONFIG_PM_SLEEP
1136 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1138 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1139 struct platform_device *pdev = to_platform_device(dev);
1142 if (dev->driver && pdrv->suspend)
1143 ret = pdrv->suspend(pdev, mesg);
1148 static int platform_legacy_resume(struct device *dev)
1150 struct platform_driver *pdrv = to_platform_driver(dev->driver);
1151 struct platform_device *pdev = to_platform_device(dev);
1154 if (dev->driver && pdrv->resume)
1155 ret = pdrv->resume(pdev);
1160 #endif /* CONFIG_PM_SLEEP */
1162 #ifdef CONFIG_SUSPEND
1164 int platform_pm_suspend(struct device *dev)
1166 struct device_driver *drv = dev->driver;
1173 if (drv->pm->suspend)
1174 ret = drv->pm->suspend(dev);
1176 ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1182 int platform_pm_resume(struct device *dev)
1184 struct device_driver *drv = dev->driver;
1191 if (drv->pm->resume)
1192 ret = drv->pm->resume(dev);
1194 ret = platform_legacy_resume(dev);
1200 #endif /* CONFIG_SUSPEND */
1202 #ifdef CONFIG_HIBERNATE_CALLBACKS
1204 int platform_pm_freeze(struct device *dev)
1206 struct device_driver *drv = dev->driver;
1213 if (drv->pm->freeze)
1214 ret = drv->pm->freeze(dev);
1216 ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1222 int platform_pm_thaw(struct device *dev)
1224 struct device_driver *drv = dev->driver;
1232 ret = drv->pm->thaw(dev);
1234 ret = platform_legacy_resume(dev);
1240 int platform_pm_poweroff(struct device *dev)
1242 struct device_driver *drv = dev->driver;
1249 if (drv->pm->poweroff)
1250 ret = drv->pm->poweroff(dev);
1252 ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1258 int platform_pm_restore(struct device *dev)
1260 struct device_driver *drv = dev->driver;
1267 if (drv->pm->restore)
1268 ret = drv->pm->restore(dev);
1270 ret = platform_legacy_resume(dev);
1276 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1278 int platform_dma_configure(struct device *dev)
1280 enum dev_dma_attr attr;
1284 ret = of_dma_configure(dev, dev->of_node, true);
1285 } else if (has_acpi_companion(dev)) {
1286 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1287 ret = acpi_dma_configure(dev, attr);
1293 static const struct dev_pm_ops platform_dev_pm_ops = {
1294 .runtime_suspend = pm_generic_runtime_suspend,
1295 .runtime_resume = pm_generic_runtime_resume,
1296 USE_PLATFORM_PM_SLEEP_OPS
1299 struct bus_type platform_bus_type = {
1301 .dev_groups = platform_dev_groups,
1302 .match = platform_match,
1303 .uevent = platform_uevent,
1304 .dma_configure = platform_dma_configure,
1305 .pm = &platform_dev_pm_ops,
1307 EXPORT_SYMBOL_GPL(platform_bus_type);
1309 static inline int __platform_match(struct device *dev, const void *drv)
1311 return platform_match(dev, (struct device_driver *)drv);
1315 * platform_find_device_by_driver - Find a platform device with a given
1317 * @start: The device to start the search from.
1318 * @drv: The device driver to look for.
1320 struct device *platform_find_device_by_driver(struct device *start,
1321 const struct device_driver *drv)
1323 return bus_find_device(&platform_bus_type, start, drv,
1326 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1328 int __init platform_bus_init(void)
1332 error = device_register(&platform_bus);
1334 put_device(&platform_bus);
1337 error = bus_register(&platform_bus_type);
1339 device_unregister(&platform_bus);
1340 of_platform_register_reconfig_notifier();