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