drivers/leds/flash/leds-aat1290.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *      LED Flash class driver for the AAT1290
   4  *      1.5A Step-Up Current Regulator for Flash LEDs
   5  *
   6  *      Copyright (C) 2015, Samsung Electronics Co., Ltd.
   7  *      Author: Jacek Anaszewski <j.anaszewski@samsung.com>
   8  */
   9
  10 #include <linux/cleanup.h>
  11 #include <linux/delay.h>
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/led-class-flash.h>
  14 #include <linux/leds.h>
  15 #include <linux/module.h>
  16 #include <linux/mutex.h>
  17 #include <linux/of.h>
  18 #include <linux/pinctrl/consumer.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/slab.h>
  21 #include <media/v4l2-flash-led-class.h>
  22
  23 #define AAT1290_MOVIE_MODE_CURRENT_ADDR 17
  24 #define AAT1290_MAX_MM_CURR_PERCENT_0   16
  25 #define AAT1290_MAX_MM_CURR_PERCENT_100 1
  26
  27 #define AAT1290_FLASH_SAFETY_TIMER_ADDR 18
  28
  29 #define AAT1290_MOVIE_MODE_CONFIG_ADDR  19
  30 #define AAT1290_MOVIE_MODE_OFF          1
  31 #define AAT1290_MOVIE_MODE_ON           3
  32
  33 #define AAT1290_MM_CURRENT_RATIO_ADDR   20
  34 #define AAT1290_MM_TO_FL_1_92           1
  35
  36 #define AAT1290_MM_TO_FL_RATIO          1000 / 1920
  37 #define AAT1290_MAX_MM_CURRENT(fl_max)  (fl_max * AAT1290_MM_TO_FL_RATIO)
  38
  39 #define AAT1290_LATCH_TIME_MIN_US       500
  40 #define AAT1290_LATCH_TIME_MAX_US       1000
  41 #define AAT1290_EN_SET_TICK_TIME_US     1
  42 #define AAT1290_FLEN_OFF_DELAY_TIME_US  10
  43 #define AAT1290_FLASH_TM_NUM_LEVELS     16
  44 #define AAT1290_MM_CURRENT_SCALE_SIZE   15
  45
  46 #define AAT1290_NAME                    "aat1290"
  47
  48
  49 struct aat1290_led_config_data {
  50         /* maximum LED current in movie mode */
  51         u32 max_mm_current;
  52         /* maximum LED current in flash mode */
  53         u32 max_flash_current;
  54         /* maximum flash timeout */
  55         u32 max_flash_tm;
  56         /* external strobe capability */
  57         bool has_external_strobe;
  58         /* max LED brightness level */
  59         enum led_brightness max_brightness;
  60 };
  61
  62 struct aat1290_led {
  63         /* platform device data */
  64         struct platform_device *pdev;
  65         /* secures access to the device */
  66         struct mutex lock;
  67
  68         /* corresponding LED Flash class device */
  69         struct led_classdev_flash fled_cdev;
  70         /* V4L2 Flash device */
  71         struct v4l2_flash *v4l2_flash;
  72
  73         /* FLEN pin */
  74         struct gpio_desc *gpio_fl_en;
  75         /* EN|SET pin  */
  76         struct gpio_desc *gpio_en_set;
  77         /* movie mode current scale */
  78         int *mm_current_scale;
  79         /* device mode */
  80         bool movie_mode;
  81 };
  82
  83 static struct aat1290_led *fled_cdev_to_led(
  84                                 struct led_classdev_flash *fled_cdev)
  85 {
  86         return container_of(fled_cdev, struct aat1290_led, fled_cdev);
  87 }
  88
  89 static struct led_classdev_flash *led_cdev_to_fled_cdev(
  90                                 struct led_classdev *led_cdev)
  91 {
  92         return container_of(led_cdev, struct led_classdev_flash, led_cdev);
  93 }
  94
  95 static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value)
  96 {
  97         int i;
  98
  99         gpiod_direction_output(led->gpio_fl_en, 0);
 100         gpiod_direction_output(led->gpio_en_set, 0);
 101
 102         udelay(AAT1290_FLEN_OFF_DELAY_TIME_US);
 103
 104         /* write address */
 105         for (i = 0; i < addr; ++i) {
 106                 udelay(AAT1290_EN_SET_TICK_TIME_US);
 107                 gpiod_direction_output(led->gpio_en_set, 0);
 108                 udelay(AAT1290_EN_SET_TICK_TIME_US);
 109                 gpiod_direction_output(led->gpio_en_set, 1);
 110         }
 111
 112         usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
 113
 114         /* write data */
 115         for (i = 0; i < value; ++i) {
 116                 udelay(AAT1290_EN_SET_TICK_TIME_US);
 117                 gpiod_direction_output(led->gpio_en_set, 0);
 118                 udelay(AAT1290_EN_SET_TICK_TIME_US);
 119                 gpiod_direction_output(led->gpio_en_set, 1);
 120         }
 121
 122         usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US);
 123 }
 124
 125 static void aat1290_set_flash_safety_timer(struct aat1290_led *led,
 126                                         unsigned int micro_sec)
 127 {
 128         struct led_classdev_flash *fled_cdev = &led->fled_cdev;
 129         struct led_flash_setting *flash_tm = &fled_cdev->timeout;
 130         int flash_tm_reg = AAT1290_FLASH_TM_NUM_LEVELS -
 131                                 (micro_sec / flash_tm->step) + 1;
 132
 133         aat1290_as2cwire_write(led, AAT1290_FLASH_SAFETY_TIMER_ADDR,
 134                                                         flash_tm_reg);
 135 }
 136
 137 /* LED subsystem callbacks */
 138
 139 static int aat1290_led_brightness_set(struct led_classdev *led_cdev,
 140                                         enum led_brightness brightness)
 141 {
 142         struct led_classdev_flash *fled_cdev = led_cdev_to_fled_cdev(led_cdev);
 143         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
 144
 145         mutex_lock(&led->lock);
 146
 147         if (brightness == 0) {
 148                 gpiod_direction_output(led->gpio_fl_en, 0);
 149                 gpiod_direction_output(led->gpio_en_set, 0);
 150                 led->movie_mode = false;
 151         } else {
 152                 if (!led->movie_mode) {
 153                         aat1290_as2cwire_write(led,
 154                                 AAT1290_MM_CURRENT_RATIO_ADDR,
 155                                 AAT1290_MM_TO_FL_1_92);
 156                         led->movie_mode = true;
 157                 }
 158
 159                 aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CURRENT_ADDR,
 160                                 AAT1290_MAX_MM_CURR_PERCENT_0 - brightness);
 161                 aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR,
 162                                 AAT1290_MOVIE_MODE_ON);
 163         }
 164
 165         mutex_unlock(&led->lock);
 166
 167         return 0;
 168 }
 169
 170 static int aat1290_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
 171                                          bool state)
 172
 173 {
 174         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
 175         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
 176         struct led_flash_setting *timeout = &fled_cdev->timeout;
 177
 178         mutex_lock(&led->lock);
 179
 180         if (state) {
 181                 aat1290_set_flash_safety_timer(led, timeout->val);
 182                 gpiod_direction_output(led->gpio_fl_en, 1);
 183         } else {
 184                 gpiod_direction_output(led->gpio_fl_en, 0);
 185                 gpiod_direction_output(led->gpio_en_set, 0);
 186         }
 187
 188         /*
 189          * To reenter movie mode after a flash event the part must be cycled
 190          * off and back on to reset the movie mode and reprogrammed via the
 191          * AS2Cwire. Therefore the brightness and movie_mode properties needs
 192          * to be updated here to reflect the actual state.
 193          */
 194         led_cdev->brightness = 0;
 195         led->movie_mode = false;
 196
 197         mutex_unlock(&led->lock);
 198
 199         return 0;
 200 }
 201
 202 static int aat1290_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
 203                                                 u32 timeout)
 204 {
 205         /*
 206          * Don't do anything - flash timeout is cached in the led-class-flash
 207          * core and will be applied in the strobe_set op, as writing the
 208          * safety timer register spuriously turns the torch mode on.
 209          */
 210
 211         return 0;
 212 }
 213
 214 static int aat1290_led_parse_dt(struct aat1290_led *led,
 215                         struct aat1290_led_config_data *cfg,
 216                         struct device_node **sub_node)
 217 {
 218         struct device *dev = &led->pdev->dev;
 219 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 220         struct pinctrl *pinctrl;
 221 #endif
 222         int ret = 0;
 223
 224         led->gpio_fl_en = devm_gpiod_get(dev, "flen", GPIOD_ASIS);
 225         if (IS_ERR(led->gpio_fl_en)) {
 226                 ret = PTR_ERR(led->gpio_fl_en);
 227                 dev_err(dev, "Unable to claim gpio \"flen\".\n");
 228                 return ret;
 229         }
 230
 231         led->gpio_en_set = devm_gpiod_get(dev, "enset", GPIOD_ASIS);
 232         if (IS_ERR(led->gpio_en_set)) {
 233                 ret = PTR_ERR(led->gpio_en_set);
 234                 dev_err(dev, "Unable to claim gpio \"enset\".\n");
 235                 return ret;
 236         }
 237
 238 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 239         pinctrl = devm_pinctrl_get_select_default(&led->pdev->dev);
 240         if (IS_ERR(pinctrl)) {
 241                 cfg->has_external_strobe = false;
 242                 dev_info(dev,
 243                          "No support for external strobe detected.\n");
 244         } else {
 245                 cfg->has_external_strobe = true;
 246         }
 247 #endif
 248
 249         struct device_node *child_node __free(device_node) =
 250                 of_get_next_available_child(dev_of_node(dev), NULL);
 251         if (!child_node) {
 252                 dev_err(dev, "No DT child node found for connected LED.\n");
 253                 return -EINVAL;
 254         }
 255
 256         ret = of_property_read_u32(child_node, "led-max-microamp",
 257                                 &cfg->max_mm_current);
 258         /*
 259          * led-max-microamp will default to 1/20 of flash-max-microamp
 260          * in case it is missing.
 261          */
 262         if (ret < 0)
 263                 dev_warn(dev,
 264                         "led-max-microamp DT property missing\n");
 265
 266         ret = of_property_read_u32(child_node, "flash-max-microamp",
 267                                 &cfg->max_flash_current);
 268         if (ret < 0) {
 269                 dev_err(dev,
 270                         "flash-max-microamp DT property missing\n");
 271                 return ret;
 272         }
 273
 274         ret = of_property_read_u32(child_node, "flash-max-timeout-us",
 275                                 &cfg->max_flash_tm);
 276         if (ret < 0) {
 277                 dev_err(dev,
 278                         "flash-max-timeout-us DT property missing\n");
 279                 return ret;
 280         }
 281
 282         *sub_node = child_node;
 283
 284         return 0;
 285 }
 286
 287 static void aat1290_led_validate_mm_current(struct aat1290_led *led,
 288                                         struct aat1290_led_config_data *cfg)
 289 {
 290         int i, b = 0, e = AAT1290_MM_CURRENT_SCALE_SIZE;
 291
 292         while (e - b > 1) {
 293                 i = b + (e - b) / 2;
 294                 if (cfg->max_mm_current < led->mm_current_scale[i])
 295                         e = i;
 296                 else
 297                         b = i;
 298         }
 299
 300         cfg->max_mm_current = led->mm_current_scale[b];
 301         cfg->max_brightness = b + 1;
 302 }
 303
 304 static int init_mm_current_scale(struct aat1290_led *led,
 305                         struct aat1290_led_config_data *cfg)
 306 {
 307         static const int max_mm_current_percent[] = {
 308                 20, 22, 25, 28, 32, 36, 40, 45, 50, 56,
 309                 63, 71, 79, 89, 100
 310         };
 311         int i, max_mm_current =
 312                         AAT1290_MAX_MM_CURRENT(cfg->max_flash_current);
 313
 314         led->mm_current_scale = devm_kzalloc(&led->pdev->dev,
 315                                         sizeof(max_mm_current_percent),
 316                                         GFP_KERNEL);
 317         if (!led->mm_current_scale)
 318                 return -ENOMEM;
 319
 320         for (i = 0; i < AAT1290_MM_CURRENT_SCALE_SIZE; ++i)
 321                 led->mm_current_scale[i] = max_mm_current *
 322                                           max_mm_current_percent[i] / 100;
 323
 324         return 0;
 325 }
 326
 327 static int aat1290_led_get_configuration(struct aat1290_led *led,
 328                                         struct aat1290_led_config_data *cfg,
 329                                         struct device_node **sub_node)
 330 {
 331         int ret;
 332
 333         ret = aat1290_led_parse_dt(led, cfg, sub_node);
 334         if (ret < 0)
 335                 return ret;
 336         /*
 337          * Init non-linear movie mode current scale basing
 338          * on the max flash current from led configuration.
 339          */
 340         ret = init_mm_current_scale(led, cfg);
 341         if (ret < 0)
 342                 return ret;
 343
 344         aat1290_led_validate_mm_current(led, cfg);
 345
 346 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 347 #else
 348         devm_kfree(&led->pdev->dev, led->mm_current_scale);
 349 #endif
 350
 351         return 0;
 352 }
 353
 354 static void aat1290_init_flash_timeout(struct aat1290_led *led,
 355                                 struct aat1290_led_config_data *cfg)
 356 {
 357         struct led_classdev_flash *fled_cdev = &led->fled_cdev;
 358         struct led_flash_setting *setting;
 359
 360         /* Init flash timeout setting */
 361         setting = &fled_cdev->timeout;
 362         setting->min = cfg->max_flash_tm / AAT1290_FLASH_TM_NUM_LEVELS;
 363         setting->max = cfg->max_flash_tm;
 364         setting->step = setting->min;
 365         setting->val = setting->max;
 366 }
 367
 368 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 369 static enum led_brightness aat1290_intensity_to_brightness(
 370                                         struct v4l2_flash *v4l2_flash,
 371                                         s32 intensity)
 372 {
 373         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
 374         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
 375         int i;
 376
 377         for (i = AAT1290_MM_CURRENT_SCALE_SIZE - 1; i >= 0; --i)
 378                 if (intensity >= led->mm_current_scale[i])
 379                         return i + 1;
 380
 381         return 1;
 382 }
 383
 384 static s32 aat1290_brightness_to_intensity(struct v4l2_flash *v4l2_flash,
 385                                         enum led_brightness brightness)
 386 {
 387         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
 388         struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
 389
 390         return led->mm_current_scale[brightness - 1];
 391 }
 392
 393 static int aat1290_led_external_strobe_set(struct v4l2_flash *v4l2_flash,
 394                                                 bool enable)
 395 {
 396         struct aat1290_led *led = fled_cdev_to_led(v4l2_flash->fled_cdev);
 397         struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
 398         struct led_classdev *led_cdev = &fled_cdev->led_cdev;
 399         struct pinctrl *pinctrl;
 400
 401         gpiod_direction_output(led->gpio_fl_en, 0);
 402         gpiod_direction_output(led->gpio_en_set, 0);
 403
 404         led->movie_mode = false;
 405         led_cdev->brightness = 0;
 406
 407         pinctrl = devm_pinctrl_get_select(&led->pdev->dev,
 408                                                 enable ? "isp" : "host");
 409         if (IS_ERR(pinctrl)) {
 410                 dev_warn(&led->pdev->dev, "Unable to switch strobe source.\n");
 411                 return PTR_ERR(pinctrl);
 412         }
 413
 414         return 0;
 415 }
 416
 417 static void aat1290_init_v4l2_flash_config(struct aat1290_led *led,
 418                                         struct aat1290_led_config_data *led_cfg,
 419                                         struct v4l2_flash_config *v4l2_sd_cfg)
 420 {
 421         struct led_classdev *led_cdev = &led->fled_cdev.led_cdev;
 422         struct led_flash_setting *s;
 423
 424         strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
 425                 sizeof(v4l2_sd_cfg->dev_name));
 426
 427         s = &v4l2_sd_cfg->intensity;
 428         s->min = led->mm_current_scale[0];
 429         s->max = led_cfg->max_mm_current;
 430         s->step = 1;
 431         s->val = s->max;
 432
 433         v4l2_sd_cfg->has_external_strobe = led_cfg->has_external_strobe;
 434 }
 435
 436 static const struct v4l2_flash_ops v4l2_flash_ops = {
 437         .external_strobe_set = aat1290_led_external_strobe_set,
 438         .intensity_to_led_brightness = aat1290_intensity_to_brightness,
 439         .led_brightness_to_intensity = aat1290_brightness_to_intensity,
 440 };
 441 #else
 442 static inline void aat1290_init_v4l2_flash_config(struct aat1290_led *led,
 443                                 struct aat1290_led_config_data *led_cfg,
 444                                 struct v4l2_flash_config *v4l2_sd_cfg)
 445 {
 446 }
 447 static const struct v4l2_flash_ops v4l2_flash_ops;
 448 #endif
 449
 450 static const struct led_flash_ops flash_ops = {
 451         .strobe_set = aat1290_led_flash_strobe_set,
 452         .timeout_set = aat1290_led_flash_timeout_set,
 453 };
 454
 455 static int aat1290_led_probe(struct platform_device *pdev)
 456 {
 457         struct device *dev = &pdev->dev;
 458         struct device_node *sub_node = NULL;
 459         struct aat1290_led *led;
 460         struct led_classdev *led_cdev;
 461         struct led_classdev_flash *fled_cdev;
 462         struct led_init_data init_data = {};
 463         struct aat1290_led_config_data led_cfg = {};
 464         struct v4l2_flash_config v4l2_sd_cfg = {};
 465         int ret;
 466
 467         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 468         if (!led)
 469                 return -ENOMEM;
 470
 471         led->pdev = pdev;
 472         platform_set_drvdata(pdev, led);
 473
 474         fled_cdev = &led->fled_cdev;
 475         fled_cdev->ops = &flash_ops;
 476         led_cdev = &fled_cdev->led_cdev;
 477
 478         ret = aat1290_led_get_configuration(led, &led_cfg, &sub_node);
 479         if (ret < 0)
 480                 return ret;
 481
 482         mutex_init(&led->lock);
 483
 484         /* Initialize LED Flash class device */
 485         led_cdev->brightness_set_blocking = aat1290_led_brightness_set;
 486         led_cdev->max_brightness = led_cfg.max_brightness;
 487         led_cdev->flags |= LED_DEV_CAP_FLASH;
 488
 489         aat1290_init_flash_timeout(led, &led_cfg);
 490
 491         init_data.fwnode = of_fwnode_handle(sub_node);
 492         init_data.devicename = AAT1290_NAME;
 493
 494         /* Register LED Flash class device */
 495         ret = led_classdev_flash_register_ext(&pdev->dev, fled_cdev,
 496                                               &init_data);
 497         if (ret < 0)
 498                 goto err_flash_register;
 499
 500         aat1290_init_v4l2_flash_config(led, &led_cfg, &v4l2_sd_cfg);
 501
 502         /* Create V4L2 Flash subdev. */
 503         led->v4l2_flash = v4l2_flash_init(dev, of_fwnode_handle(sub_node),
 504                                           fled_cdev, &v4l2_flash_ops,
 505                                           &v4l2_sd_cfg);
 506         if (IS_ERR(led->v4l2_flash)) {
 507                 ret = PTR_ERR(led->v4l2_flash);
 508                 goto error_v4l2_flash_init;
 509         }
 510
 511         return 0;
 512
 513 error_v4l2_flash_init:
 514         led_classdev_flash_unregister(fled_cdev);
 515 err_flash_register:
 516         mutex_destroy(&led->lock);
 517
 518         return ret;
 519 }
 520
 521 static void aat1290_led_remove(struct platform_device *pdev)
 522 {
 523         struct aat1290_led *led = platform_get_drvdata(pdev);
 524
 525         v4l2_flash_release(led->v4l2_flash);
 526         led_classdev_flash_unregister(&led->fled_cdev);
 527
 528         mutex_destroy(&led->lock);
 529 }
 530
 531 static const struct of_device_id aat1290_led_dt_match[] = {
 532         { .compatible = "skyworks,aat1290" },
 533         {},
 534 };
 535 MODULE_DEVICE_TABLE(of, aat1290_led_dt_match);
 536
 537 static struct platform_driver aat1290_led_driver = {
 538         .probe          = aat1290_led_probe,
 539         .remove         = aat1290_led_remove,
 540         .driver         = {
 541                 .name   = "aat1290",
 542                 .of_match_table = aat1290_led_dt_match,
 543         },
 544 };
 545
 546 module_platform_driver(aat1290_led_driver);
 547
 548 MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
 549 MODULE_DESCRIPTION("Skyworks Current Regulator for Flash LEDs");
 550 MODULE_LICENSE("GPL v2");