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