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