// SPDX-License-Identifier: GPL-2.0 /* * platform.c - platform 'pseudo' bus for legacy devices * * Copyright (c) 2002-3 Patrick Mochel * Copyright (c) 2002-3 Open Source Development Labs * * Please see Documentation/driver-api/driver-model/platform.rst for more * information. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "base.h" #include "power/power.h" /* For automatically allocated device IDs */ static DEFINE_IDA(platform_devid_ida); struct device platform_bus = { .init_name = "platform", }; EXPORT_SYMBOL_GPL(platform_bus); /** * platform_get_resource - get a resource for a device * @dev: platform device * @type: resource type * @num: resource index * * Return: a pointer to the resource or NULL on failure. */ struct resource *platform_get_resource(struct platform_device *dev, unsigned int type, unsigned int num) { u32 i; for (i = 0; i < dev->num_resources; i++) { struct resource *r = &dev->resource[i]; if (type == resource_type(r) && num-- == 0) return r; } return NULL; } EXPORT_SYMBOL_GPL(platform_get_resource); #ifdef CONFIG_HAS_IOMEM /** * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a * platform device and get resource * * @pdev: platform device to use both for memory resource lookup as well as * resource management * @index: resource index * @res: optional output parameter to store a pointer to the obtained resource. * * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code * on failure. */ void __iomem * devm_platform_get_and_ioremap_resource(struct platform_device *pdev, unsigned int index, struct resource **res) { struct resource *r; r = platform_get_resource(pdev, IORESOURCE_MEM, index); if (res) *res = r; return devm_ioremap_resource(&pdev->dev, r); } EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource); /** * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform * device * * @pdev: platform device to use both for memory resource lookup as well as * resource management * @index: resource index * * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code * on failure. */ void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev, unsigned int index) { return devm_platform_get_and_ioremap_resource(pdev, index, NULL); } EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource); /** * devm_platform_ioremap_resource_wc - write-combined variant of * devm_platform_ioremap_resource() * * @pdev: platform device to use both for memory resource lookup as well as * resource management * @index: resource index * * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code * on failure. */ void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev, unsigned int index) { struct resource *res; res = platform_get_resource(pdev, IORESOURCE_MEM, index); return devm_ioremap_resource_wc(&pdev->dev, res); } /** * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for * a platform device, retrieve the * resource by name * * @pdev: platform device to use both for memory resource lookup as well as * resource management * @name: name of the resource * * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code * on failure. */ void __iomem * devm_platform_ioremap_resource_byname(struct platform_device *pdev, const char *name) { struct resource *res; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name); return devm_ioremap_resource(&pdev->dev, res); } EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname); #endif /* CONFIG_HAS_IOMEM */ /** * platform_get_irq_optional - get an optional IRQ for a device * @dev: platform device * @num: IRQ number index * * Gets an IRQ for a platform device. Device drivers should check the return * value for errors so as to not pass a negative integer value to the * request_irq() APIs. This is the same as platform_get_irq(), except that it * does not print an error message if an IRQ can not be obtained. * * For example:: * * int irq = platform_get_irq_optional(pdev, 0); * if (irq < 0) * return irq; * * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) { int ret; #ifdef CONFIG_SPARC /* sparc does not have irqs represented as IORESOURCE_IRQ resources */ if (!dev || num >= dev->archdata.num_irqs) return -ENXIO; ret = dev->archdata.irqs[num]; goto out; #else struct resource *r; if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) { ret = of_irq_get(dev->dev.of_node, num); if (ret > 0 || ret == -EPROBE_DEFER) goto out; } r = platform_get_resource(dev, IORESOURCE_IRQ, num); if (has_acpi_companion(&dev->dev)) { if (r && r->flags & IORESOURCE_DISABLED) { ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r); if (ret) goto out; } } /* * The resources may pass trigger flags to the irqs that need * to be set up. It so happens that the trigger flags for * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER* * settings. */ if (r && r->flags & IORESOURCE_BITS) { struct irq_data *irqd; irqd = irq_get_irq_data(r->start); if (!irqd) { ret = -ENXIO; goto out; } irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); } if (r) { ret = r->start; goto out; } /* * For the index 0 interrupt, allow falling back to GpioInt * resources. While a device could have both Interrupt and GpioInt * resources, making this fallback ambiguous, in many common cases * the device will only expose one IRQ, and this fallback * allows a common code path across either kind of resource. */ if (num == 0 && has_acpi_companion(&dev->dev)) { ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); /* Our callers expect -ENXIO for missing IRQs. */ if (ret >= 0 || ret == -EPROBE_DEFER) goto out; } ret = -ENXIO; #endif out: WARN(ret == 0, "0 is an invalid IRQ number\n"); return ret; } EXPORT_SYMBOL_GPL(platform_get_irq_optional); /** * platform_get_irq - get an IRQ for a device * @dev: platform device * @num: IRQ number index * * Gets an IRQ for a platform device and prints an error message if finding the * IRQ fails. Device drivers should check the return value for errors so as to * not pass a negative integer value to the request_irq() APIs. * * For example:: * * int irq = platform_get_irq(pdev, 0); * if (irq < 0) * return irq; * * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq(struct platform_device *dev, unsigned int num) { int ret; ret = platform_get_irq_optional(dev, num); if (ret < 0 && ret != -EPROBE_DEFER) dev_err(&dev->dev, "IRQ index %u not found\n", num); return ret; } EXPORT_SYMBOL_GPL(platform_get_irq); /** * platform_irq_count - Count the number of IRQs a platform device uses * @dev: platform device * * Return: Number of IRQs a platform device uses or EPROBE_DEFER */ int platform_irq_count(struct platform_device *dev) { int ret, nr = 0; while ((ret = platform_get_irq_optional(dev, nr)) >= 0) nr++; if (ret == -EPROBE_DEFER) return ret; return nr; } EXPORT_SYMBOL_GPL(platform_irq_count); /** * platform_get_resource_byname - get a resource for a device by name * @dev: platform device * @type: resource type * @name: resource name */ struct resource *platform_get_resource_byname(struct platform_device *dev, unsigned int type, const char *name) { u32 i; for (i = 0; i < dev->num_resources; i++) { struct resource *r = &dev->resource[i]; if (unlikely(!r->name)) continue; if (type == resource_type(r) && !strcmp(r->name, name)) return r; } return NULL; } EXPORT_SYMBOL_GPL(platform_get_resource_byname); static int __platform_get_irq_byname(struct platform_device *dev, const char *name) { struct resource *r; int ret; if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) { ret = of_irq_get_byname(dev->dev.of_node, name); if (ret > 0 || ret == -EPROBE_DEFER) return ret; } r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name); if (r) { WARN(r->start == 0, "0 is an invalid IRQ number\n"); return r->start; } return -ENXIO; } /** * platform_get_irq_byname - get an IRQ for a device by name * @dev: platform device * @name: IRQ name * * Get an IRQ like platform_get_irq(), but then by name rather then by index. * * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_byname(struct platform_device *dev, const char *name) { int ret; ret = __platform_get_irq_byname(dev, name); if (ret < 0 && ret != -EPROBE_DEFER) dev_err(&dev->dev, "IRQ %s not found\n", name); return ret; } EXPORT_SYMBOL_GPL(platform_get_irq_byname); /** * platform_get_irq_byname_optional - get an optional IRQ for a device by name * @dev: platform device * @name: IRQ name * * Get an optional IRQ by name like platform_get_irq_byname(). Except that it * does not print an error message if an IRQ can not be obtained. * * Return: non-zero IRQ number on success, negative error number on failure. */ int platform_get_irq_byname_optional(struct platform_device *dev, const char *name) { return __platform_get_irq_byname(dev, name); } EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional); /** * platform_add_devices - add a numbers of platform devices * @devs: array of platform devices to add * @num: number of platform devices in array */ int platform_add_devices(struct platform_device **devs, int num) { int i, ret = 0; for (i = 0; i < num; i++) { ret = platform_device_register(devs[i]); if (ret) { while (--i >= 0) platform_device_unregister(devs[i]); break; } } return ret; } EXPORT_SYMBOL_GPL(platform_add_devices); struct platform_object { struct platform_device pdev; char name[]; }; /* * Set up default DMA mask for platform devices if the they weren't * previously set by the architecture / DT. */ static void setup_pdev_dma_masks(struct platform_device *pdev) { pdev->dev.dma_parms = &pdev->dma_parms; if (!pdev->dev.coherent_dma_mask) pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); if (!pdev->dev.dma_mask) { pdev->platform_dma_mask = DMA_BIT_MASK(32); pdev->dev.dma_mask = &pdev->platform_dma_mask; } }; /** * platform_device_put - destroy a platform device * @pdev: platform device to free * * Free all memory associated with a platform device. This function must * _only_ be externally called in error cases. All other usage is a bug. */ void platform_device_put(struct platform_device *pdev) { if (!IS_ERR_OR_NULL(pdev)) put_device(&pdev->dev); } EXPORT_SYMBOL_GPL(platform_device_put); static void platform_device_release(struct device *dev) { struct platform_object *pa = container_of(dev, struct platform_object, pdev.dev); of_device_node_put(&pa->pdev.dev); kfree(pa->pdev.dev.platform_data); kfree(pa->pdev.mfd_cell); kfree(pa->pdev.resource); kfree(pa->pdev.driver_override); kfree(pa); } /** * platform_device_alloc - create a platform device * @name: base name of the device we're adding * @id: instance id * * Create a platform device object which can have other objects attached * to it, and which will have attached objects freed when it is released. */ struct platform_device *platform_device_alloc(const char *name, int id) { struct platform_object *pa; pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL); if (pa) { strcpy(pa->name, name); pa->pdev.name = pa->name; pa->pdev.id = id; device_initialize(&pa->pdev.dev); pa->pdev.dev.release = platform_device_release; setup_pdev_dma_masks(&pa->pdev); } return pa ? &pa->pdev : NULL; } EXPORT_SYMBOL_GPL(platform_device_alloc); /** * platform_device_add_resources - add resources to a platform device * @pdev: platform device allocated by platform_device_alloc to add resources to * @res: set of resources that needs to be allocated for the device * @num: number of resources * * Add a copy of the resources to the platform device. The memory * associated with the resources will be freed when the platform device is * released. */ int platform_device_add_resources(struct platform_device *pdev, const struct resource *res, unsigned int num) { struct resource *r = NULL; if (res) { r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL); if (!r) return -ENOMEM; } kfree(pdev->resource); pdev->resource = r; pdev->num_resources = num; return 0; } EXPORT_SYMBOL_GPL(platform_device_add_resources); /** * platform_device_add_data - add platform-specific data to a platform device * @pdev: platform device allocated by platform_device_alloc to add resources to * @data: platform specific data for this platform device * @size: size of platform specific data * * Add a copy of platform specific data to the platform device's * platform_data pointer. The memory associated with the platform data * will be freed when the platform device is released. */ int platform_device_add_data(struct platform_device *pdev, const void *data, size_t size) { void *d = NULL; if (data) { d = kmemdup(data, size, GFP_KERNEL); if (!d) return -ENOMEM; } kfree(pdev->dev.platform_data); pdev->dev.platform_data = d; return 0; } EXPORT_SYMBOL_GPL(platform_device_add_data); /** * platform_device_add_properties - add built-in properties to a platform device * @pdev: platform device to add properties to * @properties: null terminated array of properties to add * * The function will take deep copy of @properties and attach the copy to the * platform device. The memory associated with properties will be freed when the * platform device is released. */ int platform_device_add_properties(struct platform_device *pdev, const struct property_entry *properties) { return device_add_properties(&pdev->dev, properties); } EXPORT_SYMBOL_GPL(platform_device_add_properties); /** * platform_device_add - add a platform device to device hierarchy * @pdev: platform device we're adding * * This is part 2 of platform_device_register(), though may be called * separately _iff_ pdev was allocated by platform_device_alloc(). */ int platform_device_add(struct platform_device *pdev) { u32 i; int ret; if (!pdev) return -EINVAL; if (!pdev->dev.parent) pdev->dev.parent = &platform_bus; pdev->dev.bus = &platform_bus_type; switch (pdev->id) { default: dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id); break; case PLATFORM_DEVID_NONE: dev_set_name(&pdev->dev, "%s", pdev->name); break; case PLATFORM_DEVID_AUTO: /* * Automatically allocated device ID. We mark it as such so * that we remember it must be freed, and we append a suffix * to avoid namespace collision with explicit IDs. */ ret = ida_alloc(&platform_devid_ida, GFP_KERNEL); if (ret < 0) goto err_out; pdev->id = ret; pdev->id_auto = true; dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id); break; } for (i = 0; i < pdev->num_resources; i++) { struct resource *p, *r = &pdev->resource[i]; if (r->name == NULL) r->name = dev_name(&pdev->dev); p = r->parent; if (!p) { if (resource_type(r) == IORESOURCE_MEM) p = &iomem_resource; else if (resource_type(r) == IORESOURCE_IO) p = &ioport_resource; } if (p) { ret = insert_resource(p, r); if (ret) { dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r); goto failed; } } } pr_debug("Registering platform device '%s'. Parent at %s\n", dev_name(&pdev->dev), dev_name(pdev->dev.parent)); ret = device_add(&pdev->dev); if (ret == 0) return ret; failed: if (pdev->id_auto) { ida_free(&platform_devid_ida, pdev->id); pdev->id = PLATFORM_DEVID_AUTO; } while (i--) { struct resource *r = &pdev->resource[i]; if (r->parent) release_resource(r); } err_out: return ret; } EXPORT_SYMBOL_GPL(platform_device_add); /** * platform_device_del - remove a platform-level device * @pdev: platform device we're removing * * Note that this function will also release all memory- and port-based * resources owned by the device (@dev->resource). This function must * _only_ be externally called in error cases. All other usage is a bug. */ void platform_device_del(struct platform_device *pdev) { u32 i; if (!IS_ERR_OR_NULL(pdev)) { device_del(&pdev->dev); if (pdev->id_auto) { ida_free(&platform_devid_ida, pdev->id); pdev->id = PLATFORM_DEVID_AUTO; } for (i = 0; i < pdev->num_resources; i++) { struct resource *r = &pdev->resource[i]; if (r->parent) release_resource(r); } } } EXPORT_SYMBOL_GPL(platform_device_del); /** * platform_device_register - add a platform-level device * @pdev: platform device we're adding */ int platform_device_register(struct platform_device *pdev) { device_initialize(&pdev->dev); setup_pdev_dma_masks(pdev); return platform_device_add(pdev); } EXPORT_SYMBOL_GPL(platform_device_register); /** * platform_device_unregister - unregister a platform-level device * @pdev: platform device we're unregistering * * Unregistration is done in 2 steps. First we release all resources * and remove it from the subsystem, then we drop reference count by * calling platform_device_put(). */ void platform_device_unregister(struct platform_device *pdev) { platform_device_del(pdev); platform_device_put(pdev); } EXPORT_SYMBOL_GPL(platform_device_unregister); /** * platform_device_register_full - add a platform-level device with * resources and platform-specific data * * @pdevinfo: data used to create device * * Returns &struct platform_device pointer on success, or ERR_PTR() on error. */ struct platform_device *platform_device_register_full( const struct platform_device_info *pdevinfo) { int ret; struct platform_device *pdev; pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id); if (!pdev) return ERR_PTR(-ENOMEM); pdev->dev.parent = pdevinfo->parent; pdev->dev.fwnode = pdevinfo->fwnode; pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode)); pdev->dev.of_node_reused = pdevinfo->of_node_reused; if (pdevinfo->dma_mask) { pdev->platform_dma_mask = pdevinfo->dma_mask; pdev->dev.dma_mask = &pdev->platform_dma_mask; pdev->dev.coherent_dma_mask = pdevinfo->dma_mask; } ret = platform_device_add_resources(pdev, pdevinfo->res, pdevinfo->num_res); if (ret) goto err; ret = platform_device_add_data(pdev, pdevinfo->data, pdevinfo->size_data); if (ret) goto err; if (pdevinfo->properties) { ret = platform_device_add_properties(pdev, pdevinfo->properties); if (ret) goto err; } ret = platform_device_add(pdev); if (ret) { err: ACPI_COMPANION_SET(&pdev->dev, NULL); platform_device_put(pdev); return ERR_PTR(ret); } return pdev; } EXPORT_SYMBOL_GPL(platform_device_register_full); static int platform_drv_probe(struct device *_dev) { struct platform_driver *drv = to_platform_driver(_dev->driver); struct platform_device *dev = to_platform_device(_dev); int ret; ret = of_clk_set_defaults(_dev->of_node, false); if (ret < 0) return ret; ret = dev_pm_domain_attach(_dev, true); if (ret) goto out; if (drv->probe) { ret = drv->probe(dev); if (ret) dev_pm_domain_detach(_dev, true); } out: if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) { dev_warn(_dev, "probe deferral not supported\n"); ret = -ENXIO; } return ret; } static int platform_drv_probe_fail(struct device *_dev) { return -ENXIO; } static int platform_drv_remove(struct device *_dev) { struct platform_driver *drv = to_platform_driver(_dev->driver); struct platform_device *dev = to_platform_device(_dev); int ret = 0; if (drv->remove) ret = drv->remove(dev); dev_pm_domain_detach(_dev, true); return ret; } static void platform_drv_shutdown(struct device *_dev) { struct platform_driver *drv = to_platform_driver(_dev->driver); struct platform_device *dev = to_platform_device(_dev); if (drv->shutdown) drv->shutdown(dev); } /** * __platform_driver_register - register a driver for platform-level devices * @drv: platform driver structure * @owner: owning module/driver */ int __platform_driver_register(struct platform_driver *drv, struct module *owner) { drv->driver.owner = owner; drv->driver.bus = &platform_bus_type; drv->driver.probe = platform_drv_probe; drv->driver.remove = platform_drv_remove; drv->driver.shutdown = platform_drv_shutdown; return driver_register(&drv->driver); } EXPORT_SYMBOL_GPL(__platform_driver_register); /** * platform_driver_unregister - unregister a driver for platform-level devices * @drv: platform driver structure */ void platform_driver_unregister(struct platform_driver *drv) { driver_unregister(&drv->driver); } EXPORT_SYMBOL_GPL(platform_driver_unregister); /** * __platform_driver_probe - register driver for non-hotpluggable device * @drv: platform driver structure * @probe: the driver probe routine, probably from an __init section * @module: module which will be the owner of the driver * * Use this instead of platform_driver_register() when you know the device * is not hotpluggable and has already been registered, and you want to * remove its run-once probe() infrastructure from memory after the driver * has bound to the device. * * One typical use for this would be with drivers for controllers integrated * into system-on-chip processors, where the controller devices have been * configured as part of board setup. * * Note that this is incompatible with deferred probing. * * Returns zero if the driver registered and bound to a device, else returns * a negative error code and with the driver not registered. */ int __init_or_module __platform_driver_probe(struct platform_driver *drv, int (*probe)(struct platform_device *), struct module *module) { int retval, code; if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) { pr_err("%s: drivers registered with %s can not be probed asynchronously\n", drv->driver.name, __func__); return -EINVAL; } /* * We have to run our probes synchronously because we check if * we find any devices to bind to and exit with error if there * are any. */ drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS; /* * Prevent driver from requesting probe deferral to avoid further * futile probe attempts. */ drv->prevent_deferred_probe = true; /* make sure driver won't have bind/unbind attributes */ drv->driver.suppress_bind_attrs = true; /* temporary section violation during probe() */ drv->probe = probe; retval = code = __platform_driver_register(drv, module); if (retval) return retval; /* * Fixup that section violation, being paranoid about code scanning * the list of drivers in order to probe new devices. Check to see * if the probe was successful, and make sure any forced probes of * new devices fail. */ spin_lock(&drv->driver.bus->p->klist_drivers.k_lock); drv->probe = NULL; if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list)) retval = -ENODEV; drv->driver.probe = platform_drv_probe_fail; spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock); if (code != retval) platform_driver_unregister(drv); return retval; } EXPORT_SYMBOL_GPL(__platform_driver_probe); /** * __platform_create_bundle - register driver and create corresponding device * @driver: platform driver structure * @probe: the driver probe routine, probably from an __init section * @res: set of resources that needs to be allocated for the device * @n_res: number of resources * @data: platform specific data for this platform device * @size: size of platform specific data * @module: module which will be the owner of the driver * * Use this in legacy-style modules that probe hardware directly and * register a single platform device and corresponding platform driver. * * Returns &struct platform_device pointer on success, or ERR_PTR() on error. */ struct platform_device * __init_or_module __platform_create_bundle( struct platform_driver *driver, int (*probe)(struct platform_device *), struct resource *res, unsigned int n_res, const void *data, size_t size, struct module *module) { struct platform_device *pdev; int error; pdev = platform_device_alloc(driver->driver.name, -1); if (!pdev) { error = -ENOMEM; goto err_out; } error = platform_device_add_resources(pdev, res, n_res); if (error) goto err_pdev_put; error = platform_device_add_data(pdev, data, size); if (error) goto err_pdev_put; error = platform_device_add(pdev); if (error) goto err_pdev_put; error = __platform_driver_probe(driver, probe, module); if (error) goto err_pdev_del; return pdev; err_pdev_del: platform_device_del(pdev); err_pdev_put: platform_device_put(pdev); err_out: return ERR_PTR(error); } EXPORT_SYMBOL_GPL(__platform_create_bundle); /** * __platform_register_drivers - register an array of platform drivers * @drivers: an array of drivers to register * @count: the number of drivers to register * @owner: module owning the drivers * * Registers platform drivers specified by an array. On failure to register a * driver, all previously registered drivers will be unregistered. Callers of * this API should use platform_unregister_drivers() to unregister drivers in * the reverse order. * * Returns: 0 on success or a negative error code on failure. */ int __platform_register_drivers(struct platform_driver * const *drivers, unsigned int count, struct module *owner) { unsigned int i; int err; for (i = 0; i < count; i++) { pr_debug("registering platform driver %ps\n", drivers[i]); err = __platform_driver_register(drivers[i], owner); if (err < 0) { pr_err("failed to register platform driver %ps: %d\n", drivers[i], err); goto error; } } return 0; error: while (i--) { pr_debug("unregistering platform driver %ps\n", drivers[i]); platform_driver_unregister(drivers[i]); } return err; } EXPORT_SYMBOL_GPL(__platform_register_drivers); /** * platform_unregister_drivers - unregister an array of platform drivers * @drivers: an array of drivers to unregister * @count: the number of drivers to unregister * * Unregisters platform drivers specified by an array. This is typically used * to complement an earlier call to platform_register_drivers(). Drivers are * unregistered in the reverse order in which they were registered. */ void platform_unregister_drivers(struct platform_driver * const *drivers, unsigned int count) { while (count--) { pr_debug("unregistering platform driver %ps\n", drivers[count]); platform_driver_unregister(drivers[count]); } } EXPORT_SYMBOL_GPL(platform_unregister_drivers); /* modalias support enables more hands-off userspace setup: * (a) environment variable lets new-style hotplug events work once system is * fully running: "modprobe $MODALIAS" * (b) sysfs attribute lets new-style coldplug recover from hotplug events * mishandled before system is fully running: "modprobe $(cat modalias)" */ static ssize_t modalias_show(struct device *dev, struct device_attribute *a, char *buf) { struct platform_device *pdev = to_platform_device(dev); int len; len = of_device_modalias(dev, buf, PAGE_SIZE); if (len != -ENODEV) return len; len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); if (len != -ENODEV) return len; len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name); return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len; } static DEVICE_ATTR_RO(modalias); static ssize_t driver_override_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct platform_device *pdev = to_platform_device(dev); char *driver_override, *old, *cp; /* We need to keep extra room for a newline */ if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL); if (!driver_override) return -ENOMEM; cp = strchr(driver_override, '\n'); if (cp) *cp = '\0'; device_lock(dev); old = pdev->driver_override; if (strlen(driver_override)) { pdev->driver_override = driver_override; } else { kfree(driver_override); pdev->driver_override = NULL; } device_unlock(dev); kfree(old); return count; } static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr, char *buf) { struct platform_device *pdev = to_platform_device(dev); ssize_t len; device_lock(dev); len = sprintf(buf, "%s\n", pdev->driver_override); device_unlock(dev); return len; } static DEVICE_ATTR_RW(driver_override); static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%d\n", dev_to_node(dev)); } static DEVICE_ATTR_RO(numa_node); static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, typeof(*dev), kobj); if (a == &dev_attr_numa_node.attr && dev_to_node(dev) == NUMA_NO_NODE) return 0; return a->mode; } static struct attribute *platform_dev_attrs[] = { &dev_attr_modalias.attr, &dev_attr_numa_node.attr, &dev_attr_driver_override.attr, NULL, }; static struct attribute_group platform_dev_group = { .attrs = platform_dev_attrs, .is_visible = platform_dev_attrs_visible, }; __ATTRIBUTE_GROUPS(platform_dev); static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) { struct platform_device *pdev = to_platform_device(dev); int rc; /* Some devices have extra OF data and an OF-style MODALIAS */ rc = of_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; rc = acpi_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX, pdev->name); return 0; } static const struct platform_device_id *platform_match_id( const struct platform_device_id *id, struct platform_device *pdev) { while (id->name[0]) { if (strcmp(pdev->name, id->name) == 0) { pdev->id_entry = id; return id; } id++; } return NULL; } /** * platform_match - bind platform device to platform driver. * @dev: device. * @drv: driver. * * Platform device IDs are assumed to be encoded like this: * "", where is a short description of the type of * device, like "pci" or "floppy", and is the enumerated * instance of the device, like '0' or '42'. Driver IDs are simply * "". So, extract the from the platform_device structure, * and compare it against the name of the driver. Return whether they match * or not. */ static int platform_match(struct device *dev, struct device_driver *drv) { struct platform_device *pdev = to_platform_device(dev); struct platform_driver *pdrv = to_platform_driver(drv); /* When driver_override is set, only bind to the matching driver */ if (pdev->driver_override) return !strcmp(pdev->driver_override, drv->name); /* Attempt an OF style match first */ if (of_driver_match_device(dev, drv)) return 1; /* Then try ACPI style match */ if (acpi_driver_match_device(dev, drv)) return 1; /* Then try to match against the id table */ if (pdrv->id_table) return platform_match_id(pdrv->id_table, pdev) != NULL; /* fall-back to driver name match */ return (strcmp(pdev->name, drv->name) == 0); } #ifdef CONFIG_PM_SLEEP static int platform_legacy_suspend(struct device *dev, pm_message_t mesg) { struct platform_driver *pdrv = to_platform_driver(dev->driver); struct platform_device *pdev = to_platform_device(dev); int ret = 0; if (dev->driver && pdrv->suspend) ret = pdrv->suspend(pdev, mesg); return ret; } static int platform_legacy_resume(struct device *dev) { struct platform_driver *pdrv = to_platform_driver(dev->driver); struct platform_device *pdev = to_platform_device(dev); int ret = 0; if (dev->driver && pdrv->resume) ret = pdrv->resume(pdev); return ret; } #endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_SUSPEND int platform_pm_suspend(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->suspend) ret = drv->pm->suspend(dev); } else { ret = platform_legacy_suspend(dev, PMSG_SUSPEND); } return ret; } int platform_pm_resume(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->resume) ret = drv->pm->resume(dev); } else { ret = platform_legacy_resume(dev); } return ret; } #endif /* CONFIG_SUSPEND */ #ifdef CONFIG_HIBERNATE_CALLBACKS int platform_pm_freeze(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->freeze) ret = drv->pm->freeze(dev); } else { ret = platform_legacy_suspend(dev, PMSG_FREEZE); } return ret; } int platform_pm_thaw(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->thaw) ret = drv->pm->thaw(dev); } else { ret = platform_legacy_resume(dev); } return ret; } int platform_pm_poweroff(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->poweroff) ret = drv->pm->poweroff(dev); } else { ret = platform_legacy_suspend(dev, PMSG_HIBERNATE); } return ret; } int platform_pm_restore(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->restore) ret = drv->pm->restore(dev); } else { ret = platform_legacy_resume(dev); } return ret; } #endif /* CONFIG_HIBERNATE_CALLBACKS */ int platform_dma_configure(struct device *dev) { enum dev_dma_attr attr; int ret = 0; if (dev->of_node) { ret = of_dma_configure(dev, dev->of_node, true); } else if (has_acpi_companion(dev)) { attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode)); ret = acpi_dma_configure(dev, attr); } return ret; } static const struct dev_pm_ops platform_dev_pm_ops = { .runtime_suspend = pm_generic_runtime_suspend, .runtime_resume = pm_generic_runtime_resume, USE_PLATFORM_PM_SLEEP_OPS }; struct bus_type platform_bus_type = { .name = "platform", .dev_groups = platform_dev_groups, .match = platform_match, .uevent = platform_uevent, .dma_configure = platform_dma_configure, .pm = &platform_dev_pm_ops, }; EXPORT_SYMBOL_GPL(platform_bus_type); static inline int __platform_match(struct device *dev, const void *drv) { return platform_match(dev, (struct device_driver *)drv); } /** * platform_find_device_by_driver - Find a platform device with a given * driver. * @start: The device to start the search from. * @drv: The device driver to look for. */ struct device *platform_find_device_by_driver(struct device *start, const struct device_driver *drv) { return bus_find_device(&platform_bus_type, start, drv, __platform_match); } EXPORT_SYMBOL_GPL(platform_find_device_by_driver); void __weak __init early_platform_cleanup(void) { } int __init platform_bus_init(void) { int error; early_platform_cleanup(); error = device_register(&platform_bus); if (error) { put_device(&platform_bus); return error; } error = bus_register(&platform_bus_type); if (error) device_unregister(&platform_bus); of_platform_register_reconfig_notifier(); return error; }