drivers/gpio/devres.c

   1 /*
   2  * drivers/gpio/devres.c - managed gpio resources
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2
   6  * as published by the Free Software Foundation.
   7  *
   8  * You should have received a copy of the GNU General Public License
   9  * along with this program; if not, write to the Free Software
  10  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  11  *
  12  * This file is based on kernel/irq/devres.c
  13  *
  14  * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/err.h>
  19 #include <linux/gpio.h>
  20 #include <linux/gpio/consumer.h>
  21 #include <linux/device.h>
  22 #include <linux/gfp.h>
  23
  24 static void devm_gpiod_release(struct device *dev, void *res)
  25 {
  26         struct gpio_desc **desc = res;
  27
  28         gpiod_put(*desc);
  29 }
  30
  31 static int devm_gpiod_match(struct device *dev, void *res, void *data)
  32 {
  33         struct gpio_desc **this = res, **gpio = data;
  34
  35         return *this == *gpio;
  36 }
  37
  38 static void devm_gpiod_release_array(struct device *dev, void *res)
  39 {
  40         struct gpio_descs **descs = res;
  41
  42         gpiod_put_array(*descs);
  43 }
  44
  45 static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
  46 {
  47         struct gpio_descs **this = res, **gpios = data;
  48
  49         return *this == *gpios;
  50 }
  51
  52 /**
  53  * devm_gpiod_get - Resource-managed gpiod_get()
  54  * @dev:        GPIO consumer
  55  * @con_id:     function within the GPIO consumer
  56  * @flags:      optional GPIO initialization flags
  57  *
  58  * Managed gpiod_get(). GPIO descriptors returned from this function are
  59  * automatically disposed on driver detach. See gpiod_get() for detailed
  60  * information about behavior and return values.
  61  */
  62 struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
  63                                               const char *con_id,
  64                                               enum gpiod_flags flags)
  65 {
  66         return devm_gpiod_get_index(dev, con_id, 0, flags);
  67 }
  68 EXPORT_SYMBOL(devm_gpiod_get);
  69
  70 /**
  71  * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
  72  * @dev: GPIO consumer
  73  * @con_id: function within the GPIO consumer
  74  * @flags: optional GPIO initialization flags
  75  *
  76  * Managed gpiod_get_optional(). GPIO descriptors returned from this function
  77  * are automatically disposed on driver detach. See gpiod_get_optional() for
  78  * detailed information about behavior and return values.
  79  */
  80 struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
  81                                                        const char *con_id,
  82                                                        enum gpiod_flags flags)
  83 {
  84         return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
  85 }
  86 EXPORT_SYMBOL(devm_gpiod_get_optional);
  87
  88 /**
  89  * devm_gpiod_get_index - Resource-managed gpiod_get_index()
  90  * @dev:        GPIO consumer
  91  * @con_id:     function within the GPIO consumer
  92  * @idx:        index of the GPIO to obtain in the consumer
  93  * @flags:      optional GPIO initialization flags
  94  *
  95  * Managed gpiod_get_index(). GPIO descriptors returned from this function are
  96  * automatically disposed on driver detach. See gpiod_get_index() for detailed
  97  * information about behavior and return values.
  98  */
  99 struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 100                                                     const char *con_id,
 101                                                     unsigned int idx,
 102                                                     enum gpiod_flags flags)
 103 {
 104         struct gpio_desc **dr;
 105         struct gpio_desc *desc;
 106
 107         dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
 108                           GFP_KERNEL);
 109         if (!dr)
 110                 return ERR_PTR(-ENOMEM);
 111
 112         desc = gpiod_get_index(dev, con_id, idx, flags);
 113         if (IS_ERR(desc)) {
 114                 devres_free(dr);
 115                 return desc;
 116         }
 117
 118         *dr = desc;
 119         devres_add(dev, dr);
 120
 121         return desc;
 122 }
 123 EXPORT_SYMBOL(devm_gpiod_get_index);
 124
 125 /**
 126  * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
 127  * @dev:        GPIO consumer
 128  * @con_id:     function within the GPIO consumer
 129  * @child:      firmware node (child of @dev)
 130  *
 131  * GPIO descriptors returned from this function are automatically disposed on
 132  * driver detach.
 133  */
 134 struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
 135                                             const char *con_id,
 136                                             struct fwnode_handle *child)
 137 {
 138         static const char * const suffixes[] = { "gpios", "gpio" };
 139         char prop_name[32]; /* 32 is max size of property name */
 140         struct gpio_desc **dr;
 141         struct gpio_desc *desc;
 142         unsigned int i;
 143
 144         dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
 145                           GFP_KERNEL);
 146         if (!dr)
 147                 return ERR_PTR(-ENOMEM);
 148
 149         for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
 150                 if (con_id)
 151                         snprintf(prop_name, sizeof(prop_name), "%s-%s",
 152                                             con_id, suffixes[i]);
 153                 else
 154                         snprintf(prop_name, sizeof(prop_name), "%s",
 155                                                                suffixes[i]);
 156
 157                 desc = fwnode_get_named_gpiod(child, prop_name);
 158                 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
 159                         break;
 160         }
 161         if (IS_ERR(desc)) {
 162                 devres_free(dr);
 163                 return desc;
 164         }
 165
 166         *dr = desc;
 167         devres_add(dev, dr);
 168
 169         return desc;
 170 }
 171 EXPORT_SYMBOL(devm_get_gpiod_from_child);
 172
 173 /**
 174  * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
 175  * @dev: GPIO consumer
 176  * @con_id: function within the GPIO consumer
 177  * @index: index of the GPIO to obtain in the consumer
 178  * @flags: optional GPIO initialization flags
 179  *
 180  * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
 181  * function are automatically disposed on driver detach. See
 182  * gpiod_get_index_optional() for detailed information about behavior and
 183  * return values.
 184  */
 185 struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
 186                                                              const char *con_id,
 187                                                              unsigned int index,
 188                                                              enum gpiod_flags flags)
 189 {
 190         struct gpio_desc *desc;
 191
 192         desc = devm_gpiod_get_index(dev, con_id, index, flags);
 193         if (IS_ERR(desc)) {
 194                 if (PTR_ERR(desc) == -ENOENT)
 195                         return NULL;
 196         }
 197
 198         return desc;
 199 }
 200 EXPORT_SYMBOL(devm_gpiod_get_index_optional);
 201
 202 /**
 203  * devm_gpiod_get_array - Resource-managed gpiod_get_array()
 204  * @dev:        GPIO consumer
 205  * @con_id:     function within the GPIO consumer
 206  * @flags:      optional GPIO initialization flags
 207  *
 208  * Managed gpiod_get_array(). GPIO descriptors returned from this function are
 209  * automatically disposed on driver detach. See gpiod_get_array() for detailed
 210  * information about behavior and return values.
 211  */
 212 struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
 213                                                      const char *con_id,
 214                                                      enum gpiod_flags flags)
 215 {
 216         struct gpio_descs **dr;
 217         struct gpio_descs *descs;
 218
 219         dr = devres_alloc(devm_gpiod_release_array,
 220                           sizeof(struct gpio_descs *), GFP_KERNEL);
 221         if (!dr)
 222                 return ERR_PTR(-ENOMEM);
 223
 224         descs = gpiod_get_array(dev, con_id, flags);
 225         if (IS_ERR(descs)) {
 226                 devres_free(dr);
 227                 return descs;
 228         }
 229
 230         *dr = descs;
 231         devres_add(dev, dr);
 232
 233         return descs;
 234 }
 235 EXPORT_SYMBOL(devm_gpiod_get_array);
 236
 237 /**
 238  * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
 239  * @dev:        GPIO consumer
 240  * @con_id:     function within the GPIO consumer
 241  * @flags:      optional GPIO initialization flags
 242  *
 243  * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
 244  * function are automatically disposed on driver detach.
 245  * See gpiod_get_array_optional() for detailed information about behavior and
 246  * return values.
 247  */
 248 struct gpio_descs *__must_check
 249 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
 250                               enum gpiod_flags flags)
 251 {
 252         struct gpio_descs *descs;
 253
 254         descs = devm_gpiod_get_array(dev, con_id, flags);
 255         if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
 256                 return NULL;
 257
 258         return descs;
 259 }
 260 EXPORT_SYMBOL(devm_gpiod_get_array_optional);
 261
 262 /**
 263  * devm_gpiod_put - Resource-managed gpiod_put()
 264  * @desc:       GPIO descriptor to dispose of
 265  *
 266  * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
 267  * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
 268  * will be disposed of by the resource management code.
 269  */
 270 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
 271 {
 272         WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
 273                 &desc));
 274 }
 275 EXPORT_SYMBOL(devm_gpiod_put);
 276
 277 /**
 278  * devm_gpiod_put_array - Resource-managed gpiod_put_array()
 279  * @descs:      GPIO descriptor array to dispose of
 280  *
 281  * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
 282  * Normally this function will not be called as the GPIOs will be disposed of
 283  * by the resource management code.
 284  */
 285 void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
 286 {
 287         WARN_ON(devres_release(dev, devm_gpiod_release_array,
 288                                devm_gpiod_match_array, &descs));
 289 }
 290 EXPORT_SYMBOL(devm_gpiod_put_array);
 291
 292
 293
 294
 295 static void devm_gpio_release(struct device *dev, void *res)
 296 {
 297         unsigned *gpio = res;
 298
 299         gpio_free(*gpio);
 300 }
 301
 302 static int devm_gpio_match(struct device *dev, void *res, void *data)
 303 {
 304         unsigned *this = res, *gpio = data;
 305
 306         return *this == *gpio;
 307 }
 308
 309 /**
 310  *      devm_gpio_request - request a GPIO for a managed device
 311  *      @dev: device to request the GPIO for
 312  *      @gpio: GPIO to allocate
 313  *      @label: the name of the requested GPIO
 314  *
 315  *      Except for the extra @dev argument, this function takes the
 316  *      same arguments and performs the same function as
 317  *      gpio_request().  GPIOs requested with this function will be
 318  *      automatically freed on driver detach.
 319  *
 320  *      If an GPIO allocated with this function needs to be freed
 321  *      separately, devm_gpio_free() must be used.
 322  */
 323
 324 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
 325 {
 326         unsigned *dr;
 327         int rc;
 328
 329         dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
 330         if (!dr)
 331                 return -ENOMEM;
 332
 333         rc = gpio_request(gpio, label);
 334         if (rc) {
 335                 devres_free(dr);
 336                 return rc;
 337         }
 338
 339         *dr = gpio;
 340         devres_add(dev, dr);
 341
 342         return 0;
 343 }
 344 EXPORT_SYMBOL(devm_gpio_request);
 345
 346 /**
 347  *      devm_gpio_request_one - request a single GPIO with initial setup
 348  *      @dev:   device to request for
 349  *      @gpio:  the GPIO number
 350  *      @flags: GPIO configuration as specified by GPIOF_*
 351  *      @label: a literal description string of this GPIO
 352  */
 353 int devm_gpio_request_one(struct device *dev, unsigned gpio,
 354                           unsigned long flags, const char *label)
 355 {
 356         unsigned *dr;
 357         int rc;
 358
 359         dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
 360         if (!dr)
 361                 return -ENOMEM;
 362
 363         rc = gpio_request_one(gpio, flags, label);
 364         if (rc) {
 365                 devres_free(dr);
 366                 return rc;
 367         }
 368
 369         *dr = gpio;
 370         devres_add(dev, dr);
 371
 372         return 0;
 373 }
 374 EXPORT_SYMBOL(devm_gpio_request_one);
 375
 376 /**
 377  *      devm_gpio_free - free a GPIO
 378  *      @dev: device to free GPIO for
 379  *      @gpio: GPIO to free
 380  *
 381  *      Except for the extra @dev argument, this function takes the
 382  *      same arguments and performs the same function as gpio_free().
 383  *      This function instead of gpio_free() should be used to manually
 384  *      free GPIOs allocated with devm_gpio_request().
 385  */
 386 void devm_gpio_free(struct device *dev, unsigned int gpio)
 387 {
 388
 389         WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
 390                 &gpio));
 391 }
 392 EXPORT_SYMBOL(devm_gpio_free);