root/drivers/staging/uwb/pal.c

DEFINITIONS

1. uwb_pal_init
2. uwb_pal_register
3. find_rc
4. uwb_rc_class_device_exists
5. uwb_pal_unregister
6. uwb_rc_pal_init

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * UWB PAL support.
   4  *
   5  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/export.h>
  10 
  11 #include "uwb.h"
  12 #include "uwb-internal.h"
  13 
  14 /**
  15  * uwb_pal_init - initialize a UWB PAL
  16  * @pal: the PAL to initialize
  17  */
  18 void uwb_pal_init(struct uwb_pal *pal)
  19 {
  20         INIT_LIST_HEAD(&pal->node);
  21 }
  22 EXPORT_SYMBOL_GPL(uwb_pal_init);
  23 
  24 /**
  25  * uwb_pal_register - register a UWB PAL
  26  * @pal: the PAL
  27  *
  28  * The PAL must be initialized with uwb_pal_init().
  29  */
  30 int uwb_pal_register(struct uwb_pal *pal)
  31 {
  32         struct uwb_rc *rc = pal->rc;
  33         int ret;
  34 
  35         if (pal->device) {
  36                 /* create a link to the uwb_rc in the PAL device's directory. */
  37                 ret = sysfs_create_link(&pal->device->kobj,
  38                                         &rc->uwb_dev.dev.kobj, "uwb_rc");
  39                 if (ret < 0)
  40                         return ret;
  41                 /* create a link to the PAL in the UWB device's directory. */
  42                 ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
  43                                         &pal->device->kobj, pal->name);
  44                 if (ret < 0) {
  45                         sysfs_remove_link(&pal->device->kobj, "uwb_rc");
  46                         return ret;
  47                 }
  48         }
  49 
  50         pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);
  51 
  52         mutex_lock(&rc->uwb_dev.mutex);
  53         list_add(&pal->node, &rc->pals);
  54         mutex_unlock(&rc->uwb_dev.mutex);
  55 
  56         return 0;
  57 }
  58 EXPORT_SYMBOL_GPL(uwb_pal_register);
  59 
  60 static int find_rc(struct device *dev, const void *data)
  61 {
  62         const struct uwb_rc *target_rc = data;
  63         struct uwb_rc *rc = dev_get_drvdata(dev);
  64 
  65         if (rc == NULL) {
  66                 WARN_ON(1);
  67                 return 0;
  68         }
  69         if (rc == target_rc) {
  70                 if (rc->ready == 0)
  71                         return 0;
  72                 else
  73                         return 1;
  74         }
  75         return 0;
  76 }
  77 
  78 /**
  79  * Given a radio controller descriptor see if it is registered.
  80  *
  81  * @returns false if the rc does not exist or is quiescing; true otherwise.
  82  */
  83 static bool uwb_rc_class_device_exists(struct uwb_rc *target_rc)
  84 {
  85         struct device *dev;
  86 
  87         dev = class_find_device(&uwb_rc_class, NULL, target_rc, find_rc);
  88 
  89         put_device(dev);
  90 
  91         return (dev != NULL);
  92 }
  93 
  94 /**
  95  * uwb_pal_unregister - unregister a UWB PAL
  96  * @pal: the PAL
  97  */
  98 void uwb_pal_unregister(struct uwb_pal *pal)
  99 {
 100         struct uwb_rc *rc = pal->rc;
 101 
 102         uwb_radio_stop(pal);
 103 
 104         mutex_lock(&rc->uwb_dev.mutex);
 105         list_del(&pal->node);
 106         mutex_unlock(&rc->uwb_dev.mutex);
 107 
 108         debugfs_remove(pal->debugfs_dir);
 109 
 110         if (pal->device) {
 111                 /* remove link to the PAL in the UWB device's directory. */
 112                 if (uwb_rc_class_device_exists(rc))
 113                         sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
 114 
 115                 /* remove link to uwb_rc in the PAL device's directory. */
 116                 sysfs_remove_link(&pal->device->kobj, "uwb_rc");
 117         }
 118 }
 119 EXPORT_SYMBOL_GPL(uwb_pal_unregister);
 120 
 121 /**
 122  * uwb_rc_pal_init - initialize the PAL related parts of a radio controller
 123  * @rc: the radio controller
 124  */
 125 void uwb_rc_pal_init(struct uwb_rc *rc)
 126 {
 127         INIT_LIST_HEAD(&rc->pals);
 128 }