drivers/leds/led-class-flash.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * LED Flash class interface
   4  *
   5  * Copyright (C) 2015 Samsung Electronics Co., Ltd.
   6  * Author: Jacek Anaszewski <[email protected]>
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/init.h>
  11 #include <linux/led-class-flash.h>
  12 #include <linux/leds.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15
  16 #define has_flash_op(fled_cdev, op)                             \
  17         (fled_cdev && fled_cdev->ops->op)
  18
  19 #define call_flash_op(fled_cdev, op, args...)           \
  20         ((has_flash_op(fled_cdev, op)) ?                        \
  21                         (fled_cdev->ops->op(fled_cdev, args)) : \
  22                         -EINVAL)
  23
  24 static const char * const led_flash_fault_names[] = {
  25         "led-over-voltage",
  26         "flash-timeout-exceeded",
  27         "controller-over-temperature",
  28         "controller-short-circuit",
  29         "led-power-supply-over-current",
  30         "indicator-led-fault",
  31         "led-under-voltage",
  32         "controller-under-voltage",
  33         "led-over-temperature",
  34 };
  35
  36 static ssize_t flash_brightness_store(struct device *dev,
  37                 struct device_attribute *attr, const char *buf, size_t size)
  38 {
  39         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  40         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
  41         unsigned long state;
  42         ssize_t ret;
  43
  44         mutex_lock(&led_cdev->led_access);
  45
  46         if (led_sysfs_is_disabled(led_cdev)) {
  47                 ret = -EBUSY;
  48                 goto unlock;
  49         }
  50
  51         ret = kstrtoul(buf, 10, &state);
  52         if (ret)
  53                 goto unlock;
  54
  55         ret = led_set_flash_brightness(fled_cdev, state);
  56         if (ret < 0)
  57                 goto unlock;
  58
  59         ret = size;
  60 unlock:
  61         mutex_unlock(&led_cdev->led_access);
  62         return ret;
  63 }
  64
  65 static ssize_t flash_brightness_show(struct device *dev,
  66                 struct device_attribute *attr, char *buf)
  67 {
  68         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  69         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
  70
  71         /* no lock needed for this */
  72         led_update_flash_brightness(fled_cdev);
  73
  74         return sprintf(buf, "%u\n", fled_cdev->brightness.val);
  75 }
  76 static DEVICE_ATTR_RW(flash_brightness);
  77
  78 static ssize_t max_flash_brightness_show(struct device *dev,
  79                 struct device_attribute *attr, char *buf)
  80 {
  81         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  82         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
  83
  84         return sprintf(buf, "%u\n", fled_cdev->brightness.max);
  85 }
  86 static DEVICE_ATTR_RO(max_flash_brightness);
  87
  88 static ssize_t flash_strobe_store(struct device *dev,
  89                 struct device_attribute *attr, const char *buf, size_t size)
  90 {
  91         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  92         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
  93         unsigned long state;
  94         ssize_t ret = -EBUSY;
  95
  96         mutex_lock(&led_cdev->led_access);
  97
  98         if (led_sysfs_is_disabled(led_cdev))
  99                 goto unlock;
 100
 101         ret = kstrtoul(buf, 10, &state);
 102         if (ret)
 103                 goto unlock;
 104
 105         if (state > 1) {
 106                 ret = -EINVAL;
 107                 goto unlock;
 108         }
 109
 110         ret = led_set_flash_strobe(fled_cdev, state);
 111         if (ret < 0)
 112                 goto unlock;
 113         ret = size;
 114 unlock:
 115         mutex_unlock(&led_cdev->led_access);
 116         return ret;
 117 }
 118
 119 static ssize_t flash_strobe_show(struct device *dev,
 120                 struct device_attribute *attr, char *buf)
 121 {
 122         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 123         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 124         bool state;
 125         int ret;
 126
 127         /* no lock needed for this */
 128         ret = led_get_flash_strobe(fled_cdev, &state);
 129         if (ret < 0)
 130                 return ret;
 131
 132         return sprintf(buf, "%u\n", state);
 133 }
 134 static DEVICE_ATTR_RW(flash_strobe);
 135
 136 static ssize_t flash_timeout_store(struct device *dev,
 137                 struct device_attribute *attr, const char *buf, size_t size)
 138 {
 139         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 140         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 141         unsigned long flash_timeout;
 142         ssize_t ret;
 143
 144         mutex_lock(&led_cdev->led_access);
 145
 146         if (led_sysfs_is_disabled(led_cdev)) {
 147                 ret = -EBUSY;
 148                 goto unlock;
 149         }
 150
 151         ret = kstrtoul(buf, 10, &flash_timeout);
 152         if (ret)
 153                 goto unlock;
 154
 155         ret = led_set_flash_timeout(fled_cdev, flash_timeout);
 156         if (ret < 0)
 157                 goto unlock;
 158
 159         ret = size;
 160 unlock:
 161         mutex_unlock(&led_cdev->led_access);
 162         return ret;
 163 }
 164
 165 static ssize_t flash_timeout_show(struct device *dev,
 166                 struct device_attribute *attr, char *buf)
 167 {
 168         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 169         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 170
 171         return sprintf(buf, "%u\n", fled_cdev->timeout.val);
 172 }
 173 static DEVICE_ATTR_RW(flash_timeout);
 174
 175 static ssize_t max_flash_timeout_show(struct device *dev,
 176                 struct device_attribute *attr, char *buf)
 177 {
 178         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 179         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 180
 181         return sprintf(buf, "%u\n", fled_cdev->timeout.max);
 182 }
 183 static DEVICE_ATTR_RO(max_flash_timeout);
 184
 185 static ssize_t flash_fault_show(struct device *dev,
 186                 struct device_attribute *attr, char *buf)
 187 {
 188         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 189         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 190         u32 fault, mask = 0x1;
 191         char *pbuf = buf;
 192         int i, ret, buf_len;
 193
 194         ret = led_get_flash_fault(fled_cdev, &fault);
 195         if (ret < 0)
 196                 return -EINVAL;
 197
 198         *buf = '\0';
 199
 200         for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) {
 201                 if (fault & mask) {
 202                         buf_len = sprintf(pbuf, "%s ",
 203                                           led_flash_fault_names[i]);
 204                         pbuf += buf_len;
 205                 }
 206                 mask <<= 1;
 207         }
 208
 209         return strlen(strcat(buf, "\n"));
 210 }
 211 static DEVICE_ATTR_RO(flash_fault);
 212
 213 static struct attribute *led_flash_strobe_attrs[] = {
 214         &dev_attr_flash_strobe.attr,
 215         NULL,
 216 };
 217
 218 static struct attribute *led_flash_timeout_attrs[] = {
 219         &dev_attr_flash_timeout.attr,
 220         &dev_attr_max_flash_timeout.attr,
 221         NULL,
 222 };
 223
 224 static struct attribute *led_flash_brightness_attrs[] = {
 225         &dev_attr_flash_brightness.attr,
 226         &dev_attr_max_flash_brightness.attr,
 227         NULL,
 228 };
 229
 230 static struct attribute *led_flash_fault_attrs[] = {
 231         &dev_attr_flash_fault.attr,
 232         NULL,
 233 };
 234
 235 static const struct attribute_group led_flash_strobe_group = {
 236         .attrs = led_flash_strobe_attrs,
 237 };
 238
 239 static const struct attribute_group led_flash_timeout_group = {
 240         .attrs = led_flash_timeout_attrs,
 241 };
 242
 243 static const struct attribute_group led_flash_brightness_group = {
 244         .attrs = led_flash_brightness_attrs,
 245 };
 246
 247 static const struct attribute_group led_flash_fault_group = {
 248         .attrs = led_flash_fault_attrs,
 249 };
 250
 251 static void led_flash_resume(struct led_classdev *led_cdev)
 252 {
 253         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 254
 255         call_flash_op(fled_cdev, flash_brightness_set,
 256                                         fled_cdev->brightness.val);
 257         call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
 258 }
 259
 260 static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
 261 {
 262         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
 263         const struct led_flash_ops *ops = fled_cdev->ops;
 264         const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;
 265
 266         int num_sysfs_groups = 0;
 267
 268         flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;
 269
 270         if (ops->flash_brightness_set)
 271                 flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;
 272
 273         if (ops->timeout_set)
 274                 flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;
 275
 276         if (ops->fault_get)
 277                 flash_groups[num_sysfs_groups++] = &led_flash_fault_group;
 278
 279         led_cdev->groups = flash_groups;
 280 }
 281
 282 int led_classdev_flash_register_ext(struct device *parent,
 283                                     struct led_classdev_flash *fled_cdev,
 284                                     struct led_init_data *init_data)
 285 {
 286         struct led_classdev *led_cdev;
 287         const struct led_flash_ops *ops;
 288         int ret;
 289
 290         if (!fled_cdev)
 291                 return -EINVAL;
 292
 293         led_cdev = &fled_cdev->led_cdev;
 294
 295         if (led_cdev->flags & LED_DEV_CAP_FLASH) {
 296                 if (!led_cdev->brightness_set_blocking)
 297                         return -EINVAL;
 298
 299                 ops = fled_cdev->ops;
 300                 if (!ops || !ops->strobe_set)
 301                         return -EINVAL;
 302
 303                 led_cdev->flash_resume = led_flash_resume;
 304
 305                 /* Select the sysfs attributes to be created for the device */
 306                 led_flash_init_sysfs_groups(fled_cdev);
 307         }
 308
 309         /* Register led class device */
 310         ret = led_classdev_register_ext(parent, led_cdev, init_data);
 311         if (ret < 0)
 312                 return ret;
 313
 314         return 0;
 315 }
 316 EXPORT_SYMBOL_GPL(led_classdev_flash_register_ext);
 317
 318 void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
 319 {
 320         if (!fled_cdev)
 321                 return;
 322
 323         led_classdev_unregister(&fled_cdev->led_cdev);
 324 }
 325 EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
 326
 327 static void devm_led_classdev_flash_release(struct device *dev, void *res)
 328 {
 329         led_classdev_flash_unregister(*(struct led_classdev_flash **)res);
 330 }
 331
 332 int devm_led_classdev_flash_register_ext(struct device *parent,
 333                                      struct led_classdev_flash *fled_cdev,
 334                                      struct led_init_data *init_data)
 335 {
 336         struct led_classdev_flash **dr;
 337         int ret;
 338
 339         dr = devres_alloc(devm_led_classdev_flash_release, sizeof(*dr),
 340                           GFP_KERNEL);
 341         if (!dr)
 342                 return -ENOMEM;
 343
 344         ret = led_classdev_flash_register_ext(parent, fled_cdev, init_data);
 345         if (ret) {
 346                 devres_free(dr);
 347                 return ret;
 348         }
 349
 350         *dr = fled_cdev;
 351         devres_add(parent, dr);
 352
 353         return 0;
 354 }
 355 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_register_ext);
 356
 357 static int devm_led_classdev_flash_match(struct device *dev,
 358                                               void *res, void *data)
 359 {
 360         struct led_classdev_flash **p = res;
 361
 362         if (WARN_ON(!p || !*p))
 363                 return 0;
 364
 365         return *p == data;
 366 }
 367
 368 void devm_led_classdev_flash_unregister(struct device *dev,
 369                                         struct led_classdev_flash *fled_cdev)
 370 {
 371         WARN_ON(devres_release(dev,
 372                                devm_led_classdev_flash_release,
 373                                devm_led_classdev_flash_match, fled_cdev));
 374 }
 375 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_unregister);
 376
 377 static void led_clamp_align(struct led_flash_setting *s)
 378 {
 379         u32 v, offset;
 380
 381         v = s->val + s->step / 2;
 382         v = clamp(v, s->min, s->max);
 383         offset = v - s->min;
 384         offset = s->step * (offset / s->step);
 385         s->val = s->min + offset;
 386 }
 387
 388 int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout)
 389 {
 390         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
 391         struct led_flash_setting *s = &fled_cdev->timeout;
 392
 393         s->val = timeout;
 394         led_clamp_align(s);
 395
 396         if (!(led_cdev->flags & LED_SUSPENDED))
 397                 return call_flash_op(fled_cdev, timeout_set, s->val);
 398
 399         return 0;
 400 }
 401 EXPORT_SYMBOL_GPL(led_set_flash_timeout);
 402
 403 int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
 404 {
 405         return call_flash_op(fled_cdev, fault_get, fault);
 406 }
 407 EXPORT_SYMBOL_GPL(led_get_flash_fault);
 408
 409 int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
 410                                 u32 brightness)
 411 {
 412         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
 413         struct led_flash_setting *s = &fled_cdev->brightness;
 414
 415         s->val = brightness;
 416         led_clamp_align(s);
 417
 418         if (!(led_cdev->flags & LED_SUSPENDED))
 419                 return call_flash_op(fled_cdev, flash_brightness_set, s->val);
 420
 421         return 0;
 422 }
 423 EXPORT_SYMBOL_GPL(led_set_flash_brightness);
 424
 425 int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
 426 {
 427         struct led_flash_setting *s = &fled_cdev->brightness;
 428         u32 brightness;
 429
 430         if (has_flash_op(fled_cdev, flash_brightness_get)) {
 431                 int ret = call_flash_op(fled_cdev, flash_brightness_get,
 432                                                 &brightness);
 433                 if (ret < 0)
 434                         return ret;
 435
 436                 s->val = brightness;
 437         }
 438
 439         return 0;
 440 }
 441 EXPORT_SYMBOL_GPL(led_update_flash_brightness);
 442
 443 MODULE_AUTHOR("Jacek Anaszewski <[email protected]>");
 444 MODULE_DESCRIPTION("LED Flash class interface");
 445 MODULE_LICENSE("GPL v2");