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