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platform.c

/*
 * 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/platform_device.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 "base.h"

#define to_platform_driver(drv)     (container_of((drv), struct platform_driver, driver))

struct device platform_bus = {
      .bus_id           = "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 ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
                         IORESOURCE_IRQ|IORESOURCE_DMA))
                == type)
                  if (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,
                  char *name)
{
      int i;

      for (i = 0; i < dev->num_resources; i++) {
            struct resource *r = &dev->resource[i];

            if ((r->flags & (IORESOURCE_IO|IORESOURCE_MEM|
                         IORESOURCE_IRQ|IORESOURCE_DMA)) == type)
                  if (!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, 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;

      d = kmalloc(size, GFP_KERNEL);
      if (d) {
            memcpy(d, data, size);
            pdev->dev.platform_data = d;
      }
      return d ? 0 : -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)
            snprintf(pdev->dev.bus_id, BUS_ID_SIZE, "%s.%d", pdev->name,
                   pdev->id);
      else
            strlcpy(pdev->dev.bus_id, pdev->name, BUS_ID_SIZE);

      for (i = 0; i < pdev->num_resources; i++) {
            struct resource *p, *r = &pdev->resource[i];

            if (r->name == NULL)
                  r->name = pdev->dev.bus_id;

            p = r->parent;
            if (!p) {
                  if (r->flags & IORESOURCE_MEM)
                        p = &iomem_resource;
                  else if (r->flags & IORESOURCE_IO)
                        p = &ioport_resource;
            }

            if (p && insert_resource(p, r)) {
                  printk(KERN_ERR
                         "%s: failed to claim resource %d\n",
                         pdev->dev.bus_id, i);
                  ret = -EBUSY;
                  goto failed;
            }
      }

      pr_debug("Registering platform device '%s'. Parent at %s\n",
             pdev->dev.bus_id, pdev->dev.parent->bus_id);

      ret = device_add(&pdev->dev);
      if (ret == 0)
            return ret;

 failed:
      while (--i >= 0)
            if (pdev->resource[i].flags & (IORESOURCE_MEM|IORESOURCE_IO))
                  release_resource(&pdev->resource[i]);
      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];
                  if (r->flags & (IORESOURCE_MEM|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(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);

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);
}

static int platform_drv_suspend(struct device *_dev, pm_message_t state)
{
      struct platform_driver *drv = to_platform_driver(_dev->driver);
      struct platform_device *dev = to_platform_device(_dev);

      return drv->suspend(dev, state);
}

static int platform_drv_resume(struct device *_dev)
{
      struct platform_driver *drv = to_platform_driver(_dev->driver);
      struct platform_device *dev = to_platform_device(_dev);

      return drv->resume(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;
      if (drv->suspend)
            drv->driver.suspend = platform_drv_suspend;
      if (drv->resume)
            drv->driver.resume = platform_drv_resume;
      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;

      /* 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.klist_drivers.k_lock);
      drv->probe = NULL;
      if (code == 0 && list_empty(&drv->driver.klist_devices.k_list))
            retval = -ENODEV;
      drv->driver.probe = platform_drv_probe_fail;
      spin_unlock(&platform_bus_type.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=platform:%s", pdev->name);
      return 0;
}


/**
 *    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 = container_of(dev, struct platform_device, dev);

      return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0);
}

static int platform_suspend(struct device *dev, pm_message_t mesg)
{
      int ret = 0;

      if (dev->driver && dev->driver->suspend)
            ret = dev->driver->suspend(dev, mesg);

      return ret;
}

static int platform_suspend_late(struct device *dev, pm_message_t mesg)
{
      struct platform_driver *drv = to_platform_driver(dev->driver);
      struct platform_device *pdev = container_of(dev, struct platform_device, dev);
      int ret = 0;

      if (dev->driver && drv->suspend_late)
            ret = drv->suspend_late(pdev, mesg);

      return ret;
}

static int platform_resume_early(struct device *dev)
{
      struct platform_driver *drv = to_platform_driver(dev->driver);
      struct platform_device *pdev = container_of(dev, struct platform_device, dev);
      int ret = 0;

      if (dev->driver && drv->resume_early)
            ret = drv->resume_early(pdev);

      return ret;
}

static int platform_resume(struct device * dev)
{
      int ret = 0;

      if (dev->driver && dev->driver->resume)
            ret = dev->driver->resume(dev);

      return ret;
}

struct bus_type platform_bus_type = {
      .name       = "platform",
      .dev_attrs  = platform_dev_attrs,
      .match            = platform_match,
      .uevent           = platform_uevent,
      .suspend    = platform_suspend,
      .suspend_late     = platform_suspend_late,
      .resume_early     = platform_resume_early,
      .resume           = platform_resume,
};
EXPORT_SYMBOL_GPL(platform_bus_type);

int __init platform_bus_init(void)
{
      int error;

      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 & *dev->dma_mask;
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
#endif

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