drivers/extcon/devres.c

   1 /*
   2  * drivers/extcon/devres.c - EXTCON device's resource management
   3  *
   4  * Copyright (C) 2016 Samsung Electronics
   5  * Author: Chanwoo Choi <cw00.choi@samsung.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include "extcon.h"
  18
  19 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
  20 {
  21         struct extcon_dev **r = res;
  22
  23         if (WARN_ON(!r || !*r))
  24                 return 0;
  25
  26         return *r == data;
  27 }
  28
  29 static void devm_extcon_dev_release(struct device *dev, void *res)
  30 {
  31         extcon_dev_free(*(struct extcon_dev **)res);
  32 }
  33
  34
  35 static void devm_extcon_dev_unreg(struct device *dev, void *res)
  36 {
  37         extcon_dev_unregister(*(struct extcon_dev **)res);
  38 }
  39
  40 struct extcon_dev_notifier_devres {
  41         struct extcon_dev *edev;
  42         unsigned int id;
  43         struct notifier_block *nb;
  44 };
  45
  46 static void devm_extcon_dev_notifier_unreg(struct device *dev, void *res)
  47 {
  48         struct extcon_dev_notifier_devres *this = res;
  49
  50         extcon_unregister_notifier(this->edev, this->id, this->nb);
  51 }
  52
  53 static void devm_extcon_dev_notifier_all_unreg(struct device *dev, void *res)
  54 {
  55         struct extcon_dev_notifier_devres *this = res;
  56
  57         extcon_unregister_notifier_all(this->edev, this->nb);
  58 }
  59
  60 /**
  61  * devm_extcon_dev_allocate - Allocate managed extcon device
  62  * @dev:                the device owning the extcon device being created
  63  * @supported_cable:    the array of the supported external connectors
  64  *                      ending with EXTCON_NONE.
  65  *
  66  * This function manages automatically the memory of extcon device using device
  67  * resource management and simplify the control of freeing the memory of extcon
  68  * device.
  69  *
  70  * Returns the pointer memory of allocated extcon_dev if success
  71  * or ERR_PTR(err) if fail
  72  */
  73 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
  74                                         const unsigned int *supported_cable)
  75 {
  76         struct extcon_dev **ptr, *edev;
  77
  78         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
  79         if (!ptr)
  80                 return ERR_PTR(-ENOMEM);
  81
  82         edev = extcon_dev_allocate(supported_cable);
  83         if (IS_ERR(edev)) {
  84                 devres_free(ptr);
  85                 return edev;
  86         }
  87
  88         edev->dev.parent = dev;
  89
  90         *ptr = edev;
  91         devres_add(dev, ptr);
  92
  93         return edev;
  94 }
  95 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
  96
  97 /**
  98  * devm_extcon_dev_free() - Resource-managed extcon_dev_unregister()
  99  * @dev:        the device owning the extcon device being created
 100  * @edev:       the extcon device to be freed
 101  *
 102  * Free the memory that is allocated with devm_extcon_dev_allocate()
 103  * function.
 104  */
 105 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 106 {
 107         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 108                                devm_extcon_dev_match, edev));
 109 }
 110 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 111
 112 /**
 113  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 114  * @dev:        the device owning the extcon device being created
 115  * @edev:       the extcon device to be registered
 116  *
 117  * this function, that extcon device is automatically unregistered on driver
 118  * detach. Internally this function calls extcon_dev_register() function.
 119  * To get more information, refer that function.
 120  *
 121  * If extcon device is registered with this function and the device needs to be
 122  * unregistered separately, devm_extcon_dev_unregister() should be used.
 123  *
 124  * Returns 0 if success or negaive error number if failure.
 125  */
 126 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
 127 {
 128         struct extcon_dev **ptr;
 129         int ret;
 130
 131         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
 132         if (!ptr)
 133                 return -ENOMEM;
 134
 135         ret = extcon_dev_register(edev);
 136         if (ret) {
 137                 devres_free(ptr);
 138                 return ret;
 139         }
 140
 141         *ptr = edev;
 142         devres_add(dev, ptr);
 143
 144         return 0;
 145 }
 146 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
 147
 148 /**
 149  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
 150  * @dev:        the device owning the extcon device being created
 151  * @edev:       the extcon device to unregistered
 152  *
 153  * Unregister extcon device that is registered with devm_extcon_dev_register()
 154  * function.
 155  */
 156 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
 157 {
 158         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
 159                                devm_extcon_dev_match, edev));
 160 }
 161 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
 162
 163 /**
 164  * devm_extcon_register_notifier() - Resource-managed extcon_register_notifier()
 165  * @dev:        the device owning the extcon device being created
 166  * @edev:       the extcon device
 167  * @id:         the unique id among the extcon enumeration
 168  * @nb:         a notifier block to be registered
 169  *
 170  * This function manages automatically the notifier of extcon device using
 171  * device resource management and simplify the control of unregistering
 172  * the notifier of extcon device.
 173  *
 174  * Note that the second parameter given to the callback of nb (val) is
 175  * "old_state", not the current state. The current state can be retrieved
 176  * by looking at the third pameter (edev pointer)'s state value.
 177  *
 178  * Returns 0 if success or negaive error number if failure.
 179  */
 180 int devm_extcon_register_notifier(struct device *dev, struct extcon_dev *edev,
 181                                 unsigned int id, struct notifier_block *nb)
 182 {
 183         struct extcon_dev_notifier_devres *ptr;
 184         int ret;
 185
 186         ptr = devres_alloc(devm_extcon_dev_notifier_unreg, sizeof(*ptr),
 187                                 GFP_KERNEL);
 188         if (!ptr)
 189                 return -ENOMEM;
 190
 191         ret = extcon_register_notifier(edev, id, nb);
 192         if (ret) {
 193                 devres_free(ptr);
 194                 return ret;
 195         }
 196
 197         ptr->edev = edev;
 198         ptr->id = id;
 199         ptr->nb = nb;
 200         devres_add(dev, ptr);
 201
 202         return 0;
 203 }
 204 EXPORT_SYMBOL(devm_extcon_register_notifier);
 205
 206 /**
 207  * devm_extcon_unregister_notifier()
 208                         - Resource-managed extcon_unregister_notifier()
 209  * @dev:        the device owning the extcon device being created
 210  * @edev:       the extcon device
 211  * @id:         the unique id among the extcon enumeration
 212  * @nb:         a notifier block to be registered
 213  */
 214 void devm_extcon_unregister_notifier(struct device *dev,
 215                                 struct extcon_dev *edev, unsigned int id,
 216                                 struct notifier_block *nb)
 217 {
 218         WARN_ON(devres_release(dev, devm_extcon_dev_notifier_unreg,
 219                                devm_extcon_dev_match, edev));
 220 }
 221 EXPORT_SYMBOL(devm_extcon_unregister_notifier);
 222
 223 /**
 224  * devm_extcon_register_notifier_all()
 225  *              - Resource-managed extcon_register_notifier_all()
 226  * @dev:        the device owning the extcon device being created
 227  * @edev:       the extcon device
 228  * @nb:         a notifier block to be registered
 229  *
 230  * This function manages automatically the notifier of extcon device using
 231  * device resource management and simplify the control of unregistering
 232  * the notifier of extcon device. To get more information, refer that function.
 233  *
 234  * Returns 0 if success or negaive error number if failure.
 235  */
 236 int devm_extcon_register_notifier_all(struct device *dev, struct extcon_dev *edev,
 237                                 struct notifier_block *nb)
 238 {
 239         struct extcon_dev_notifier_devres *ptr;
 240         int ret;
 241
 242         ptr = devres_alloc(devm_extcon_dev_notifier_all_unreg, sizeof(*ptr),
 243                                 GFP_KERNEL);
 244         if (!ptr)
 245                 return -ENOMEM;
 246
 247         ret = extcon_register_notifier_all(edev, nb);
 248         if (ret) {
 249                 devres_free(ptr);
 250                 return ret;
 251         }
 252
 253         ptr->edev = edev;
 254         ptr->nb = nb;
 255         devres_add(dev, ptr);
 256
 257         return 0;
 258 }
 259 EXPORT_SYMBOL(devm_extcon_register_notifier_all);
 260
 261 /**
 262  * devm_extcon_unregister_notifier_all()
 263  *              - Resource-managed extcon_unregister_notifier_all()
 264  * @dev:        the device owning the extcon device being created
 265  * @edev:       the extcon device
 266  * @nb:         a notifier block to be registered
 267  */
 268 void devm_extcon_unregister_notifier_all(struct device *dev,
 269                                 struct extcon_dev *edev,
 270                                 struct notifier_block *nb)
 271 {
 272         WARN_ON(devres_release(dev, devm_extcon_dev_notifier_all_unreg,
 273                                devm_extcon_dev_match, edev));
 274 }
 275 EXPORT_SYMBOL(devm_extcon_unregister_notifier_all);