Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / base / platform.c
diff --git a/kernel/drivers/base/platform.c b/kernel/drivers/base/platform.c
new file mode 100644 (file)
index 0000000..ebf034b
--- /dev/null
@@ -0,0 +1,1330 @@
+/*
+ * 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 <linux/string.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/bootmem.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/idr.h>
+#include <linux/acpi.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/limits.h>
+
+#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);
+
+/**
+ * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
+ * @pdev: platform device
+ *
+ * This is called before platform_device_add() such that any pdev_archdata may
+ * be setup before the platform_notifier is called.  So if a user needs to
+ * manipulate any relevant information in the pdev_archdata they can do:
+ *
+ *     platform_device_alloc()
+ *     ... manipulate ...
+ *     platform_device_add()
+ *
+ * And if they don't care they can just call platform_device_register() and
+ * everything will just work out.
+ */
+void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
+{
+}
+
+/**
+ * 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)
+{
+#ifdef CONFIG_SPARC
+       /* sparc does not have irqs represented as IORESOURCE_IRQ resources */
+       if (!dev || num >= dev->archdata.num_irqs)
+               return -ENXIO;
+       return dev->archdata.irqs[num];
+#else
+       struct resource *r;
+       if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
+               int ret;
+
+               ret = of_irq_get(dev->dev.of_node, num);
+               if (ret >= 0 || ret == -EPROBE_DEFER)
+                       return ret;
+       }
+
+       r = platform_get_resource(dev, IORESOURCE_IRQ, num);
+       /*
+        * 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)
+               irqd_set_trigger_type(irq_get_irq_data(r->start),
+                                     r->flags & IORESOURCE_BITS);
+
+       return r ? r->start : -ENXIO;
+#endif
+}
+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 (unlikely(!r->name))
+                       continue;
+
+               if (type == resource_type(r) && !strcmp(r->name, name))
+                       return r;
+       }
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(platform_get_resource_byname);
+
+/**
+ * platform_get_irq_byname - get an IRQ for a device by name
+ * @dev: platform device
+ * @name: IRQ name
+ */
+int platform_get_irq_byname(struct platform_device *dev, const char *name)
+{
+       struct resource *r;
+
+       if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
+               int ret;
+
+               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);
+       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[];
+};
+
+/**
+ * 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 (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;
+               arch_setup_pdev_archdata(&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 - 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;
+
+       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_simple_get(&platform_devid_ida, 0, 0, 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 && insert_resource(p, r)) {
+                       dev_err(&pdev->dev, "failed to claim resource %d\n", 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:
+       if (pdev->id_auto) {
+               ida_simple_remove(&platform_devid_ida, pdev->id);
+               pdev->id = PLATFORM_DEVID_AUTO;
+       }
+
+       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);
+       }
+
+ 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)
+{
+       int i;
+
+       if (pdev) {
+               device_del(&pdev->dev);
+
+               if (pdev->id_auto) {
+                       ida_simple_remove(&platform_devid_ida, pdev->id);
+                       pdev->id = PLATFORM_DEVID_AUTO;
+               }
+
+               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);
+       arch_setup_pdev_archdata(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 = -ENOMEM;
+       struct platform_device *pdev;
+
+       pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
+       if (!pdev)
+               goto err_alloc;
+
+       pdev->dev.parent = pdevinfo->parent;
+       pdev->dev.fwnode = pdevinfo->fwnode;
+
+       if (pdevinfo->dma_mask) {
+               /*
+                * This memory isn't freed when the device is put,
+                * I don't have a nice idea for that though.  Conceptually
+                * dma_mask in struct device should not be a pointer.
+                * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
+                */
+               pdev->dev.dma_mask =
+                       kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
+               if (!pdev->dev.dma_mask)
+                       goto err;
+
+               *pdev->dev.dma_mask = pdevinfo->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;
+
+       ret = platform_device_add(pdev);
+       if (ret) {
+err:
+               ACPI_COMPANION_SET(&pdev->dev, NULL);
+               kfree(pdev->dev.dma_mask);
+
+err_alloc:
+               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 != -EPROBE_DEFER) {
+               ret = drv->probe(dev);
+               if (ret)
+                       dev_pm_domain_detach(_dev, true);
+       }
+
+       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;
+
+       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);
+
+       drv->shutdown(dev);
+       dev_pm_domain_detach(_dev, true);
+}
+
+/**
+ * __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;
+       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 - 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;
+
+       /*
+        * 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);
+
+       /*
+        * 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);
+
+/* 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_get_modalias(dev, buf, PAGE_SIZE -1);
+       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 = pdev->driver_override, *cp;
+
+       if (count > PATH_MAX)
+               return -EINVAL;
+
+       driver_override = kstrndup(buf, count, GFP_KERNEL);
+       if (!driver_override)
+               return -ENOMEM;
+
+       cp = strchr(driver_override, '\n');
+       if (cp)
+               *cp = '\0';
+
+       if (strlen(driver_override)) {
+               pdev->driver_override = driver_override;
+       } else {
+               kfree(driver_override);
+               pdev->driver_override = NULL;
+       }
+
+       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);
+
+       return sprintf(buf, "%s\n", pdev->driver_override);
+}
+static DEVICE_ATTR_RW(driver_override);
+
+
+static struct attribute *platform_dev_attrs[] = {
+       &dev_attr_modalias.attr,
+       &dev_attr_driver_override.attr,
+       NULL,
+};
+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:
+ * "<name><instance>", where <name> is a short description of the type of
+ * device, like "pci" or "floppy", and <instance> is the enumerated
+ * instance of the device, like '0' or '42'.  Driver IDs are simply
+ * "<name>".  So, extract the <name> 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 */
+
+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,
+       .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);
+       of_platform_register_reconfig_notifier();
+       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 - register early platform driver
+ * @epdrv: early_platform driver structure
+ * @buf: string passed from early_param()
+ *
+ * Helper function for early_platform_init() / early_platform_init_buffer()
+ */
+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 - adds a number of early platform devices
+ * @devs: array of early platform devices to add
+ * @num: number of early platform devices in array
+ *
+ * Used by early architecture code to register early platform devices and
+ * their platform data.
+ */
+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) {
+                       pm_runtime_early_init(dev);
+                       INIT_LIST_HEAD(&dev->devres_head);
+                       list_add_tail(&dev->devres_head,
+                                     &early_platform_device_list);
+               }
+       }
+}
+
+/**
+ * early_platform_driver_register_all - register early platform drivers
+ * @class_str: string to identify early platform driver class
+ *
+ * Used by architecture code to register all early platform drivers
+ * for a certain class. If omitted then only early platform drivers
+ * with matching kernel command line class parameters will be registered.
+ */
+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 - find early platform device matching driver
+ * @epdrv: early platform driver structure
+ * @id: id to match against
+ */
+static struct platform_device * __init
+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 - check if early platform driver has matching devices
+ * @epdrv: early platform driver structure
+ * @id: return true if id or above exists
+ */
+static int __init 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 - probe drivers matching class_str and 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_warn("%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) {
+                       /*
+                        * Set up a sensible init_name to enable
+                        * dev_name() and others to be used before the
+                        * rest of the driver core is initialized.
+                        */
+                       if (!match->dev.init_name && slab_is_available()) {
+                               if (match->id != -1)
+                                       match->dev.init_name =
+                                               kasprintf(GFP_KERNEL, "%s.%d",
+                                                         match->name,
+                                                         match->id);
+                               else
+                                       match->dev.init_name =
+                                               kasprintf(GFP_KERNEL, "%s",
+                                                         match->name);
+
+                               if (!match->dev.init_name)
+                                       return -ENOMEM;
+                       }
+
+                       if (epdrv->pdrv->probe(match))
+                               pr_warn("%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 - probe a class of registered drivers
+ * @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
+ *
+ * Used by architecture code to probe registered early platform drivers
+ * within a certain class. For probe to happen a registered early platform
+ * device matching a registered early platform driver is needed.
+ */
+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));
+       }
+}
+