/* * platform.c - platform 'pseudo' bus for legacy devices * * Copyright (c) 2002-3 Patrick Mochel * Copyright (c) 2002-3 Open Source Development Labs * * This file is released under the GPLv2 * * Please see Documentation/driver-model/platform.txt for more * information. */ #include #include #include #include #include #include #include #include #include #include "base.h" #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \ driver)) 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 */ struct resource *platform_get_resource(struct platform_device *dev, unsigned int type, unsigned int num) { int 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); /** * platform_get_irq - get an IRQ for a device * @dev: platform device * @num: IRQ number index */ int platform_get_irq(struct platform_device *dev, unsigned int num) { struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num); return r ? r->start : -ENXIO; } EXPORT_SYMBOL_GPL(platform_get_irq); /** * 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) { int i; for (i = 0; i < dev->num_resources; i++) { struct resource *r = &dev->resource[i]; if (type == resource_type(r) && !strcmp(r->name, name)) return r; } return NULL; } EXPORT_SYMBOL_GPL(platform_get_resource_byname); /** * platform_get_irq - get an IRQ for a device * @dev: platform device * @name: IRQ name */ int platform_get_irq_byname(struct platform_device *dev, const char *name) { struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name); return r ? r->start : -ENXIO; } EXPORT_SYMBOL_GPL(platform_get_irq_byname); /** * 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[1]; }; /** * platform_device_put * @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 (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); kfree(pa->pdev.dev.platform_data); kfree(pa->pdev.resource); kfree(pa); } /** * platform_device_alloc * @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(struct platform_object) + strlen(name), 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; } return pa ? &pa->pdev : NULL; } EXPORT_SYMBOL_GPL(platform_device_alloc); /** * platform_device_add_resources * @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, struct resource *res, unsigned int num) { struct resource *r; r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL); if (r) { memcpy(r, res, sizeof(struct resource) * num); pdev->resource = r; pdev->num_resources = num; } return r ? 0 : -ENOMEM; } EXPORT_SYMBOL_GPL(platform_device_add_resources); /** * platform_device_add_data * @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 = kmemdup(data, size, GFP_KERNEL); if (d) { pdev->dev.platform_data = d; return 0; } return -ENOMEM; } EXPORT_SYMBOL_GPL(platform_device_add_data); /** * 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) { int i, ret = 0; if (!pdev) return -EINVAL; if (!pdev->dev.parent) pdev->dev.parent = &platform_bus; pdev->dev.bus = &platform_bus_type; if (pdev->id != -1) dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id); else dev_set_name(&pdev->dev, "%s", pdev->name); 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 && insert_resource(p, r)) { printk(KERN_ERR "%s: failed to claim resource %d\n", dev_name(&pdev->dev), i); ret = -EBUSY; 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: while (--i >= 0) { struct resource *r = &pdev->resource[i]; unsigned long type = resource_type(r); if (type == IORESOURCE_MEM || type == IORESOURCE_IO) release_resource(r); } 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) { int i; if (pdev) { device_del(&pdev->dev); for (i = 0; i < pdev->num_resources; i++) { struct resource *r = &pdev->resource[i]; unsigned long type = resource_type(r); if (type == IORESOURCE_MEM || type == IORESOURCE_IO) 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); 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_simple * @name: base name of the device we're adding * @id: instance id * @res: set of resources that needs to be allocated for the device * @num: number of resources * * This function creates a simple platform device that requires minimal * resource and memory management. Canned release function freeing memory * allocated for the device allows drivers using such devices to be * unloaded without waiting for the last reference to the device to be * dropped. * * This interface is primarily intended for use with legacy drivers which * probe hardware directly. Because such drivers create sysfs device nodes * themselves, rather than letting system infrastructure handle such device * enumeration tasks, they don't fully conform to the Linux driver model. * In particular, when such drivers are built as modules, they can't be * "hotplugged". */ struct platform_device *platform_device_register_simple(const char *name, int id, struct resource *res, unsigned int num) { struct platform_device *pdev; int retval; pdev = platform_device_alloc(name, id); if (!pdev) { retval = -ENOMEM; goto error; } if (num) { retval = platform_device_add_resources(pdev, res, num); if (retval) goto error; } retval = platform_device_add(pdev); if (retval) goto error; return pdev; error: platform_device_put(pdev); return ERR_PTR(retval); } EXPORT_SYMBOL_GPL(platform_device_register_simple); /** * platform_device_register_data * @parent: parent device for the device we're adding * @name: base name of the device we're adding * @id: instance id * @data: platform specific data for this platform device * @size: size of platform specific data * * This function creates a simple platform device that requires minimal * resource and memory management. Canned release function freeing memory * allocated for the device allows drivers using such devices to be * unloaded without waiting for the last reference to the device to be * dropped. */ struct platform_device *platform_device_register_data( struct device *parent, const char *name, int id, const void *data, size_t size) { struct platform_device *pdev; int retval; pdev = platform_device_alloc(name, id); if (!pdev) { retval = -ENOMEM; goto error; } pdev->dev.parent = parent; if (size) { retval = platform_device_add_data(pdev, data, size); if (retval) goto error; } retval = platform_device_add(pdev); if (retval) goto error; return pdev; error: platform_device_put(pdev); return ERR_PTR(retval); } EXPORT_SYMBOL_GPL(platform_device_register_data); 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); return drv->probe(dev); } 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); return drv->remove(dev); } 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); drv->shutdown(dev); } /** * platform_driver_register * @drv: platform driver structure */ int platform_driver_register(struct platform_driver *drv) { drv->driver.bus = &platform_bus_type; if (drv->probe) drv->driver.probe = platform_drv_probe; if (drv->remove) drv->driver.remove = platform_drv_remove; if (drv->shutdown) drv->driver.shutdown = platform_drv_shutdown; return driver_register(&drv->driver); } EXPORT_SYMBOL_GPL(platform_driver_register); /** * platform_driver_unregister * @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 * * 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. * * 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 *)) { int retval, code; /* 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); /* * 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(&platform_bus_type.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(&platform_bus_type.p->klist_drivers.k_lock); if (code != retval) platform_driver_unregister(drv); return retval; } EXPORT_SYMBOL_GPL(platform_driver_probe); /* 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 = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name); return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len; } static struct device_attribute platform_dev_attrs[] = { __ATTR_RO(modalias), __ATTR_NULL, }; static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) { struct platform_device *pdev = to_platform_device(dev); add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX, (pdev->id_entry) ? pdev->id_entry->name : pdev->name); return 0; } static const struct platform_device_id *platform_match_id( 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); /* match against the id table first */ 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; } static int platform_pm_prepare(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (drv && drv->pm && drv->pm->prepare) ret = drv->pm->prepare(dev); return ret; } static void platform_pm_complete(struct device *dev) { struct device_driver *drv = dev->driver; if (drv && drv->pm && drv->pm->complete) drv->pm->complete(dev); } #else /* !CONFIG_PM_SLEEP */ #define platform_pm_prepare NULL #define platform_pm_complete NULL #endif /* !CONFIG_PM_SLEEP */ #ifdef CONFIG_SUSPEND static 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; } static int platform_pm_suspend_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->suspend_noirq) ret = drv->pm->suspend_noirq(dev); } return ret; } static 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; } static int platform_pm_resume_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->resume_noirq) ret = drv->pm->resume_noirq(dev); } return ret; } #else /* !CONFIG_SUSPEND */ #define platform_pm_suspend NULL #define platform_pm_resume NULL #define platform_pm_suspend_noirq NULL #define platform_pm_resume_noirq NULL #endif /* !CONFIG_SUSPEND */ #ifdef CONFIG_HIBERNATION static 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; } static int platform_pm_freeze_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->freeze_noirq) ret = drv->pm->freeze_noirq(dev); } return ret; } static 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; } static int platform_pm_thaw_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->thaw_noirq) ret = drv->pm->thaw_noirq(dev); } return ret; } static 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; } static int platform_pm_poweroff_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->poweroff_noirq) ret = drv->pm->poweroff_noirq(dev); } return ret; } static 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; } static int platform_pm_restore_noirq(struct device *dev) { struct device_driver *drv = dev->driver; int ret = 0; if (!drv) return 0; if (drv->pm) { if (drv->pm->restore_noirq) ret = drv->pm->restore_noirq(dev); } return ret; } #else /* !CONFIG_HIBERNATION */ #define platform_pm_freeze NULL #define platform_pm_thaw NULL #define platform_pm_poweroff NULL #define platform_pm_restore NULL #define platform_pm_freeze_noirq NULL #define platform_pm_thaw_noirq NULL #define platform_pm_poweroff_noirq NULL #define platform_pm_restore_noirq NULL #endif /* !CONFIG_HIBERNATION */ #ifdef CONFIG_PM_RUNTIME int __weak platform_pm_runtime_suspend(struct device *dev) { return -ENOSYS; }; int __weak platform_pm_runtime_resume(struct device *dev) { return -ENOSYS; }; int __weak platform_pm_runtime_idle(struct device *dev) { return -ENOSYS; }; #else /* !CONFIG_PM_RUNTIME */ #define platform_pm_runtime_suspend NULL #define platform_pm_runtime_resume NULL #define platform_pm_runtime_idle NULL #endif /* !CONFIG_PM_RUNTIME */ static const struct dev_pm_ops platform_dev_pm_ops = { .prepare = platform_pm_prepare, .complete = platform_pm_complete, .suspend = platform_pm_suspend, .resume = platform_pm_resume, .freeze = platform_pm_freeze, .thaw = platform_pm_thaw, .poweroff = platform_pm_poweroff, .restore = platform_pm_restore, .suspend_noirq = platform_pm_suspend_noirq, .resume_noirq = platform_pm_resume_noirq, .freeze_noirq = platform_pm_freeze_noirq, .thaw_noirq = platform_pm_thaw_noirq, .poweroff_noirq = platform_pm_poweroff_noirq, .restore_noirq = platform_pm_restore_noirq, .runtime_suspend = platform_pm_runtime_suspend, .runtime_resume = platform_pm_runtime_resume, .runtime_idle = platform_pm_runtime_idle, }; struct bus_type platform_bus_type = { .name = "platform", .dev_attrs = platform_dev_attrs, .match = platform_match, .uevent = platform_uevent, .pm = &platform_dev_pm_ops, }; EXPORT_SYMBOL_GPL(platform_bus_type); int __init platform_bus_init(void) { int error; early_platform_cleanup(); error = device_register(&platform_bus); if (error) return error; error = bus_register(&platform_bus_type); if (error) device_unregister(&platform_bus); return error; } #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK u64 dma_get_required_mask(struct device *dev) { u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT); u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT)); u64 mask; if (!high_totalram) { /* convert to mask just covering totalram */ low_totalram = (1 << (fls(low_totalram) - 1)); low_totalram += low_totalram - 1; mask = low_totalram; } else { high_totalram = (1 << (fls(high_totalram) - 1)); high_totalram += high_totalram - 1; mask = (((u64)high_totalram) << 32) + 0xffffffff; } return mask; } EXPORT_SYMBOL_GPL(dma_get_required_mask); #endif static __initdata LIST_HEAD(early_platform_driver_list); static __initdata LIST_HEAD(early_platform_device_list); /** * early_platform_driver_register * @epdrv: early_platform driver structure * @buf: string passed from early_param() */ int __init early_platform_driver_register(struct early_platform_driver *epdrv, char *buf) { char *tmp; int n; /* Simply add the driver to the end of the global list. * Drivers will by default be put on the list in compiled-in order. */ if (!epdrv->list.next) { INIT_LIST_HEAD(&epdrv->list); list_add_tail(&epdrv->list, &early_platform_driver_list); } /* If the user has specified device then make sure the driver * gets prioritized. The driver of the last device specified on * command line will be put first on the list. */ n = strlen(epdrv->pdrv->driver.name); if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) { list_move(&epdrv->list, &early_platform_driver_list); /* Allow passing parameters after device name */ if (buf[n] == '\0' || buf[n] == ',') epdrv->requested_id = -1; else { epdrv->requested_id = simple_strtoul(&buf[n + 1], &tmp, 10); if (buf[n] != '.' || (tmp == &buf[n + 1])) { epdrv->requested_id = EARLY_PLATFORM_ID_ERROR; n = 0; } else n += strcspn(&buf[n + 1], ",") + 1; } if (buf[n] == ',') n++; if (epdrv->bufsize) { memcpy(epdrv->buffer, &buf[n], min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1)); epdrv->buffer[epdrv->bufsize - 1] = '\0'; } } return 0; } /** * early_platform_add_devices - add a numbers of early platform devices * @devs: array of early platform devices to add * @num: number of early platform devices in array */ void __init early_platform_add_devices(struct platform_device **devs, int num) { struct device *dev; int i; /* simply add the devices to list */ for (i = 0; i < num; i++) { dev = &devs[i]->dev; if (!dev->devres_head.next) { INIT_LIST_HEAD(&dev->devres_head); list_add_tail(&dev->devres_head, &early_platform_device_list); } } } /** * early_platform_driver_register_all * @class_str: string to identify early platform driver class */ void __init early_platform_driver_register_all(char *class_str) { /* The "class_str" parameter may or may not be present on the kernel * command line. If it is present then there may be more than one * matching parameter. * * Since we register our early platform drivers using early_param() * we need to make sure that they also get registered in the case * when the parameter is missing from the kernel command line. * * We use parse_early_options() to make sure the early_param() gets * called at least once. The early_param() may be called more than * once since the name of the preferred device may be specified on * the kernel command line. early_platform_driver_register() handles * this case for us. */ parse_early_options(class_str); } /** * early_platform_match * @epdrv: early platform driver structure * @id: id to match against */ static __init struct platform_device * early_platform_match(struct early_platform_driver *epdrv, int id) { struct platform_device *pd; list_for_each_entry(pd, &early_platform_device_list, dev.devres_head) if (platform_match(&pd->dev, &epdrv->pdrv->driver)) if (pd->id == id) return pd; return NULL; } /** * early_platform_left * @epdrv: early platform driver structure * @id: return true if id or above exists */ static __init int early_platform_left(struct early_platform_driver *epdrv, int id) { struct platform_device *pd; list_for_each_entry(pd, &early_platform_device_list, dev.devres_head) if (platform_match(&pd->dev, &epdrv->pdrv->driver)) if (pd->id >= id) return 1; return 0; } /** * early_platform_driver_probe_id * @class_str: string to identify early platform driver class * @id: id to match against * @nr_probe: number of platform devices to successfully probe before exiting */ static int __init early_platform_driver_probe_id(char *class_str, int id, int nr_probe) { struct early_platform_driver *epdrv; struct platform_device *match; int match_id; int n = 0; int left = 0; list_for_each_entry(epdrv, &early_platform_driver_list, list) { /* only use drivers matching our class_str */ if (strcmp(class_str, epdrv->class_str)) continue; if (id == -2) { match_id = epdrv->requested_id; left = 1; } else { match_id = id; left += early_platform_left(epdrv, id); /* skip requested id */ switch (epdrv->requested_id) { case EARLY_PLATFORM_ID_ERROR: case EARLY_PLATFORM_ID_UNSET: break; default: if (epdrv->requested_id == id) match_id = EARLY_PLATFORM_ID_UNSET; } } switch (match_id) { case EARLY_PLATFORM_ID_ERROR: pr_warning("%s: unable to parse %s parameter\n", class_str, epdrv->pdrv->driver.name); /* fall-through */ case EARLY_PLATFORM_ID_UNSET: match = NULL; break; default: match = early_platform_match(epdrv, match_id); } if (match) { if (epdrv->pdrv->probe(match)) pr_warning("%s: unable to probe %s early.\n", class_str, match->name); else n++; } if (n >= nr_probe) break; } if (left) return n; else return -ENODEV; } /** * early_platform_driver_probe * @class_str: string to identify early platform driver class * @nr_probe: number of platform devices to successfully probe before exiting * @user_only: only probe user specified early platform devices */ int __init early_platform_driver_probe(char *class_str, int nr_probe, int user_only) { int k, n, i; n = 0; for (i = -2; n < nr_probe; i++) { k = early_platform_driver_probe_id(class_str, i, nr_probe - n); if (k < 0) break; n += k; if (user_only) break; } return n; } /** * early_platform_cleanup - clean up early platform code */ void __init early_platform_cleanup(void) { struct platform_device *pd, *pd2; /* clean up the devres list used to chain devices */ list_for_each_entry_safe(pd, pd2, &early_platform_device_list, dev.devres_head) { list_del(&pd->dev.devres_head); memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head)); } }