target/linux/ipq806x/patches-4.4/009-5-watchdog-Create-watchdog-device-in-watchdog_dev-c.patch

   1 From 32ecc6392654a0db34b310e8924b5b2c3b8bf503 Mon Sep 17 00:00:00 2001
   2 From: Guenter Roeck <linux@roeck-us.net>
   3 Date: Fri, 25 Dec 2015 16:01:40 -0800
   4 Subject: watchdog: Create watchdog device in watchdog_dev.c
   5
   6 The watchdog character device is currently created in watchdog_dev.c,
   7 and the watchdog device in watchdog_core.c. This results in
   8 cross-dependencies, since device creation needs to know the watchdog
   9 character device number as well as the watchdog class, both of which
  10 reside in watchdog_dev.c.
  11
  12 Create the watchdog device in watchdog_dev.c to simplify the code.
  13
  14 Inspired by earlier patch set from Damien Riegel.
  15
  16 Cc: Damien Riegel <damien.riegel@savoirfairelinux.com>
  17 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  18 Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
  19 ---
  20  drivers/watchdog/watchdog_core.c | 33 ++++--------------
  21  drivers/watchdog/watchdog_core.h |  4 +--
  22  drivers/watchdog/watchdog_dev.c  | 73 +++++++++++++++++++++++++++++++++-------
  23  3 files changed, 69 insertions(+), 41 deletions(-)
  24
  25 --- a/drivers/watchdog/watchdog_core.c
  26 +++ b/drivers/watchdog/watchdog_core.c
  27 @@ -42,7 +42,6 @@
  28  #include "watchdog_core.h"     /* For watchdog_dev_register/... */
  29
  30  static DEFINE_IDA(watchdog_ida);
  31 -static struct class *watchdog_class;
  32
  33  /*
  34   * Deferred Registration infrastructure.
  35 @@ -194,7 +193,7 @@ EXPORT_SYMBOL_GPL(watchdog_set_restart_p
  36
  37  static int __watchdog_register_device(struct watchdog_device *wdd)
  38  {
  39 -       int ret, id = -1, devno;
  40 +       int ret, id = -1;
  41
  42         if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
  43                 return -EINVAL;
  44 @@ -247,16 +246,6 @@ static int __watchdog_register_device(st
  45                 }
  46         }
  47
  48 -       devno = wdd->cdev.dev;
  49 -       wdd->dev = device_create(watchdog_class, wdd->parent, devno,
  50 -                                       wdd, "watchdog%d", wdd->id);
  51 -       if (IS_ERR(wdd->dev)) {
  52 -               watchdog_dev_unregister(wdd);
  53 -               ida_simple_remove(&watchdog_ida, id);
  54 -               ret = PTR_ERR(wdd->dev);
  55 -               return ret;
  56 -       }
  57 -
  58         if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
  59                 wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
  60
  61 @@ -265,9 +254,7 @@ static int __watchdog_register_device(st
  62                         dev_err(wdd->dev, "Cannot register reboot notifier (%d)\n",
  63                                 ret);
  64                         watchdog_dev_unregister(wdd);
  65 -                       device_destroy(watchdog_class, devno);
  66                         ida_simple_remove(&watchdog_ida, wdd->id);
  67 -                       wdd->dev = NULL;
  68                         return ret;
  69                 }
  70         }
  71 @@ -311,9 +298,6 @@ EXPORT_SYMBOL_GPL(watchdog_register_devi
  72
  73  static void __watchdog_unregister_device(struct watchdog_device *wdd)
  74  {
  75 -       int ret;
  76 -       int devno;
  77 -
  78         if (wdd == NULL)
  79                 return;
  80
  81 @@ -323,13 +307,8 @@ static void __watchdog_unregister_device
  82         if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status))
  83                 unregister_reboot_notifier(&wdd->reboot_nb);
  84
  85 -       devno = wdd->cdev.dev;
  86 -       ret = watchdog_dev_unregister(wdd);
  87 -       if (ret)
  88 -               pr_err("error unregistering /dev/watchdog (err=%d)\n", ret);
  89 -       device_destroy(watchdog_class, devno);
  90 +       watchdog_dev_unregister(wdd);
  91         ida_simple_remove(&watchdog_ida, wdd->id);
  92 -       wdd->dev = NULL;
  93  }
  94
  95  /**
  96 @@ -370,9 +349,11 @@ static int __init watchdog_deferred_regi
  97
  98  static int __init watchdog_init(void)
  99  {
 100 -       watchdog_class = watchdog_dev_init();
 101 -       if (IS_ERR(watchdog_class))
 102 -               return PTR_ERR(watchdog_class);
 103 +       int err;
 104 +
 105 +       err = watchdog_dev_init();
 106 +       if (err < 0)
 107 +               return err;
 108
 109         watchdog_deferred_registration();
 110         return 0;
 111 --- a/drivers/watchdog/watchdog_core.h
 112 +++ b/drivers/watchdog/watchdog_core.h
 113 @@ -32,6 +32,6 @@
 114   *     Functions/procedures to be called by the core
 115   */
 116  extern int watchdog_dev_register(struct watchdog_device *);
 117 -extern int watchdog_dev_unregister(struct watchdog_device *);
 118 -extern struct class * __init watchdog_dev_init(void);
 119 +extern void watchdog_dev_unregister(struct watchdog_device *);
 120 +extern int __init watchdog_dev_init(void);
 121  extern void __exit watchdog_dev_exit(void);
 122 --- a/drivers/watchdog/watchdog_dev.c
 123 +++ b/drivers/watchdog/watchdog_dev.c
 124 @@ -628,17 +628,18 @@ static struct miscdevice watchdog_miscde
 125  };
 126
 127  /*
 128 - *     watchdog_dev_register: register a watchdog device
 129 + *     watchdog_cdev_register: register watchdog character device
 130   *     @wdd: watchdog device
 131 + *     @devno: character device number
 132   *
 133 - *     Register a watchdog device including handling the legacy
 134 + *     Register a watchdog character device including handling the legacy
 135   *     /dev/watchdog node. /dev/watchdog is actually a miscdevice and
 136   *     thus we set it up like that.
 137   */
 138
 139 -int watchdog_dev_register(struct watchdog_device *wdd)
 140 +static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
 141  {
 142 -       int err, devno;
 143 +       int err;
 144
 145         if (wdd->id == 0) {
 146                 old_wdd = wdd;
 147 @@ -656,7 +657,6 @@ int watchdog_dev_register(struct watchdo
 148         }
 149
 150         /* Fill in the data structures */
 151 -       devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
 152         cdev_init(&wdd->cdev, &watchdog_fops);
 153         wdd->cdev.owner = wdd->ops->owner;
 154
 155 @@ -674,13 +674,14 @@ int watchdog_dev_register(struct watchdo
 156  }
 157
 158  /*
 159 - *     watchdog_dev_unregister: unregister a watchdog device
 160 + *     watchdog_cdev_unregister: unregister watchdog character device
 161   *     @watchdog: watchdog device
 162   *
 163 - *     Unregister the watchdog and if needed the legacy /dev/watchdog device.
 164 + *     Unregister watchdog character device and if needed the legacy
 165 + *     /dev/watchdog device.
 166   */
 167
 168 -int watchdog_dev_unregister(struct watchdog_device *wdd)
 169 +static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 170  {
 171         mutex_lock(&wdd->lock);
 172         set_bit(WDOG_UNREGISTERED, &wdd->status);
 173 @@ -691,7 +692,6 @@ int watchdog_dev_unregister(struct watch
 174                 misc_deregister(&watchdog_miscdev);
 175                 old_wdd = NULL;
 176         }
 177 -       return 0;
 178  }
 179
 180  static struct class watchdog_class = {
 181 @@ -701,29 +701,76 @@ static struct class watchdog_class = {
 182  };
 183
 184  /*
 185 + *     watchdog_dev_register: register a watchdog device
 186 + *     @wdd: watchdog device
 187 + *
 188 + *     Register a watchdog device including handling the legacy
 189 + *     /dev/watchdog node. /dev/watchdog is actually a miscdevice and
 190 + *     thus we set it up like that.
 191 + */
 192 +
 193 +int watchdog_dev_register(struct watchdog_device *wdd)
 194 +{
 195 +       struct device *dev;
 196 +       dev_t devno;
 197 +       int ret;
 198 +
 199 +       devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
 200 +
 201 +       ret = watchdog_cdev_register(wdd, devno);
 202 +       if (ret)
 203 +               return ret;
 204 +
 205 +       dev = device_create(&watchdog_class, wdd->parent, devno, wdd,
 206 +                           "watchdog%d", wdd->id);
 207 +       if (IS_ERR(dev)) {
 208 +               watchdog_cdev_unregister(wdd);
 209 +               return PTR_ERR(dev);
 210 +       }
 211 +       wdd->dev = dev;
 212 +
 213 +       return ret;
 214 +}
 215 +
 216 +/*
 217 + *     watchdog_dev_unregister: unregister a watchdog device
 218 + *     @watchdog: watchdog device
 219 + *
 220 + *     Unregister watchdog device and if needed the legacy
 221 + *     /dev/watchdog device.
 222 + */
 223 +
 224 +void watchdog_dev_unregister(struct watchdog_device *wdd)
 225 +{
 226 +       watchdog_cdev_unregister(wdd);
 227 +       device_destroy(&watchdog_class, wdd->dev->devt);
 228 +       wdd->dev = NULL;
 229 +}
 230 +
 231 +/*
 232   *     watchdog_dev_init: init dev part of watchdog core
 233   *
 234   *     Allocate a range of chardev nodes to use for watchdog devices
 235   */
 236
 237 -struct class * __init watchdog_dev_init(void)
 238 +int __init watchdog_dev_init(void)
 239  {
 240         int err;
 241
 242         err = class_register(&watchdog_class);
 243         if (err < 0) {
 244                 pr_err("couldn't register class\n");
 245 -               return ERR_PTR(err);
 246 +               return err;
 247         }
 248
 249         err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
 250         if (err < 0) {
 251                 pr_err("watchdog: unable to allocate char dev region\n");
 252                 class_unregister(&watchdog_class);
 253 -               return ERR_PTR(err);
 254 +               return err;
 255         }
 256
 257 -       return &watchdog_class;
 258 +       return 0;
 259  }
 260
 261  /*