drivers/uwb/umc-dev.c

   1 /*
   2  * UWB Multi-interface Controller device management.
   3  *
   4  * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
   5  *
   6  * This file is released under the GNU GPL v2.
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/uwb/umc.h>
  10
  11 static void umc_device_release(struct device *dev)
  12 {
  13         struct umc_dev *umc = to_umc_dev(dev);
  14
  15         kfree(umc);
  16 }
  17
  18 /**
  19  * umc_device_create - allocate a child UMC device
  20  * @parent: parent of the new UMC device.
  21  * @n:      index of the new device.
  22  *
  23  * The new UMC device will have a bus ID of the parent with '-n'
  24  * appended.
  25  */
  26 struct umc_dev *umc_device_create(struct device *parent, int n)
  27 {
  28         struct umc_dev *umc;
  29
  30         umc = kzalloc(sizeof(struct umc_dev), GFP_KERNEL);
  31         if (umc) {
  32                 dev_set_name(&umc->dev, "%s-%d", dev_name(parent), n);
  33                 umc->dev.parent  = parent;
  34                 umc->dev.bus     = &umc_bus_type;
  35                 umc->dev.release = umc_device_release;
  36
  37                 umc->dev.dma_mask = parent->dma_mask;
  38         }
  39         return umc;
  40 }
  41 EXPORT_SYMBOL_GPL(umc_device_create);
  42
  43 /**
  44  * umc_device_register - register a UMC device
  45  * @umc: pointer to the UMC device
  46  *
  47  * The memory resource for the UMC device is acquired and the device
  48  * registered with the system.
  49  */
  50 int umc_device_register(struct umc_dev *umc)
  51 {
  52         int err;
  53
  54         err = request_resource(umc->resource.parent, &umc->resource);
  55         if (err < 0) {
  56                 dev_err(&umc->dev, "can't allocate resource range "
  57                         "%016Lx to %016Lx: %d\n",
  58                         (unsigned long long)umc->resource.start,
  59                         (unsigned long long)umc->resource.end,
  60                         err);
  61                 goto error_request_resource;
  62         }
  63
  64         err = device_register(&umc->dev);
  65         if (err < 0)
  66                 goto error_device_register;
  67         return 0;
  68
  69 error_device_register:
  70         release_resource(&umc->resource);
  71 error_request_resource:
  72         return err;
  73 }
  74 EXPORT_SYMBOL_GPL(umc_device_register);
  75
  76 /**
  77  * umc_device_unregister - unregister a UMC device
  78  * @umc: pointer to the UMC device
  79  *
  80  * First we unregister the device, make sure the driver can do it's
  81  * resource release thing and then we try to release any left over
  82  * resources. We take a ref to the device, to make sure it doesn't
  83  * dissapear under our feet.
  84  */
  85 void umc_device_unregister(struct umc_dev *umc)
  86 {
  87         struct device *dev;
  88         if (!umc)
  89                 return;
  90         dev = get_device(&umc->dev);
  91         device_unregister(&umc->dev);
  92         release_resource(&umc->resource);
  93         put_device(dev);
  94 }
  95 EXPORT_SYMBOL_GPL(umc_device_unregister);