drivers/leds/leds-lp55xx-common.c

   1 /*
   2  * LP5521/LP5523/LP55231/LP5562 Common Driver
   3  *
   4  * Copyright 2012 Texas Instruments
   5  *
   6  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Derived from leds-lp5521.c, leds-lp5523.c
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/delay.h>
  17 #include <linux/firmware.h>
  18 #include <linux/i2c.h>
  19 #include <linux/leds.h>
  20 #include <linux/module.h>
  21 #include <linux/platform_data/leds-lp55xx.h>
  22
  23 #include "leds-lp55xx-common.h"
  24
  25 /* External clock rate */
  26 #define LP55XX_CLK_32K                  32768
  27
  28 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
  29 {
  30         return container_of(cdev, struct lp55xx_led, cdev);
  31 }
  32
  33 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
  34 {
  35         return cdev_to_lp55xx_led(dev_get_drvdata(dev));
  36 }
  37
  38 static void lp55xx_reset_device(struct lp55xx_chip *chip)
  39 {
  40         struct lp55xx_device_config *cfg = chip->cfg;
  41         u8 addr = cfg->reset.addr;
  42         u8 val  = cfg->reset.val;
  43
  44         /* no error checking here because no ACK from the device after reset */
  45         lp55xx_write(chip, addr, val);
  46 }
  47
  48 static int lp55xx_detect_device(struct lp55xx_chip *chip)
  49 {
  50         struct lp55xx_device_config *cfg = chip->cfg;
  51         u8 addr = cfg->enable.addr;
  52         u8 val  = cfg->enable.val;
  53         int ret;
  54
  55         ret = lp55xx_write(chip, addr, val);
  56         if (ret)
  57                 return ret;
  58
  59         usleep_range(1000, 2000);
  60
  61         ret = lp55xx_read(chip, addr, &val);
  62         if (ret)
  63                 return ret;
  64
  65         if (val != cfg->enable.val)
  66                 return -ENODEV;
  67
  68         return 0;
  69 }
  70
  71 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
  72 {
  73         struct lp55xx_device_config *cfg = chip->cfg;
  74
  75         if (!cfg->post_init_device)
  76                 return 0;
  77
  78         return cfg->post_init_device(chip);
  79 }
  80
  81 static ssize_t lp55xx_show_current(struct device *dev,
  82                             struct device_attribute *attr,
  83                             char *buf)
  84 {
  85         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
  86
  87         return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
  88 }
  89
  90 static ssize_t lp55xx_store_current(struct device *dev,
  91                              struct device_attribute *attr,
  92                              const char *buf, size_t len)
  93 {
  94         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
  95         struct lp55xx_chip *chip = led->chip;
  96         unsigned long curr;
  97
  98         if (kstrtoul(buf, 0, &curr))
  99                 return -EINVAL;
 100
 101         if (curr > led->max_current)
 102                 return -EINVAL;
 103
 104         if (!chip->cfg->set_led_current)
 105                 return len;
 106
 107         mutex_lock(&chip->lock);
 108         chip->cfg->set_led_current(led, (u8)curr);
 109         mutex_unlock(&chip->lock);
 110
 111         return len;
 112 }
 113
 114 static ssize_t lp55xx_show_max_current(struct device *dev,
 115                             struct device_attribute *attr,
 116                             char *buf)
 117 {
 118         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
 119
 120         return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
 121 }
 122
 123 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
 124                 lp55xx_store_current);
 125 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
 126
 127 static struct attribute *lp55xx_led_attributes[] = {
 128         &dev_attr_led_current.attr,
 129         &dev_attr_max_current.attr,
 130         NULL,
 131 };
 132
 133 static struct attribute_group lp55xx_led_attr_group = {
 134         .attrs = lp55xx_led_attributes
 135 };
 136
 137 static void lp55xx_set_brightness(struct led_classdev *cdev,
 138                              enum led_brightness brightness)
 139 {
 140         struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
 141
 142         led->brightness = (u8)brightness;
 143         schedule_work(&led->brightness_work);
 144 }
 145
 146 static int lp55xx_init_led(struct lp55xx_led *led,
 147                         struct lp55xx_chip *chip, int chan)
 148 {
 149         struct lp55xx_platform_data *pdata = chip->pdata;
 150         struct lp55xx_device_config *cfg = chip->cfg;
 151         struct device *dev = &chip->cl->dev;
 152         char name[32];
 153         int ret;
 154         int max_channel = cfg->max_channel;
 155
 156         if (chan >= max_channel) {
 157                 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
 158                 return -EINVAL;
 159         }
 160
 161         if (pdata->led_config[chan].led_current == 0)
 162                 return 0;
 163
 164         led->led_current = pdata->led_config[chan].led_current;
 165         led->max_current = pdata->led_config[chan].max_current;
 166         led->chan_nr = pdata->led_config[chan].chan_nr;
 167
 168         if (led->chan_nr >= max_channel) {
 169                 dev_err(dev, "Use channel numbers between 0 and %d\n",
 170                         max_channel - 1);
 171                 return -EINVAL;
 172         }
 173
 174         led->cdev.brightness_set = lp55xx_set_brightness;
 175
 176         if (pdata->led_config[chan].name) {
 177                 led->cdev.name = pdata->led_config[chan].name;
 178         } else {
 179                 snprintf(name, sizeof(name), "%s:channel%d",
 180                         pdata->label ? : chip->cl->name, chan);
 181                 led->cdev.name = name;
 182         }
 183
 184         /*
 185          * register led class device for each channel and
 186          * add device attributes
 187          */
 188
 189         ret = led_classdev_register(dev, &led->cdev);
 190         if (ret) {
 191                 dev_err(dev, "led register err: %d\n", ret);
 192                 return ret;
 193         }
 194
 195         ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group);
 196         if (ret) {
 197                 dev_err(dev, "led sysfs err: %d\n", ret);
 198                 led_classdev_unregister(&led->cdev);
 199                 return ret;
 200         }
 201
 202         return 0;
 203 }
 204
 205 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
 206 {
 207         struct lp55xx_chip *chip = context;
 208         struct device *dev = &chip->cl->dev;
 209
 210         if (!fw) {
 211                 dev_err(dev, "firmware request failed\n");
 212                 goto out;
 213         }
 214
 215         /* handling firmware data is chip dependent */
 216         mutex_lock(&chip->lock);
 217
 218         chip->fw = fw;
 219         if (chip->cfg->firmware_cb)
 220                 chip->cfg->firmware_cb(chip);
 221
 222         mutex_unlock(&chip->lock);
 223
 224 out:
 225         /* firmware should be released for other channel use */
 226         release_firmware(chip->fw);
 227 }
 228
 229 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
 230 {
 231         const char *name = chip->cl->name;
 232         struct device *dev = &chip->cl->dev;
 233
 234         return request_firmware_nowait(THIS_MODULE, true, name, dev,
 235                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
 236 }
 237
 238 static ssize_t lp55xx_show_engine_select(struct device *dev,
 239                             struct device_attribute *attr,
 240                             char *buf)
 241 {
 242         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 243         struct lp55xx_chip *chip = led->chip;
 244
 245         return sprintf(buf, "%d\n", chip->engine_idx);
 246 }
 247
 248 static ssize_t lp55xx_store_engine_select(struct device *dev,
 249                              struct device_attribute *attr,
 250                              const char *buf, size_t len)
 251 {
 252         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 253         struct lp55xx_chip *chip = led->chip;
 254         unsigned long val;
 255         int ret;
 256
 257         if (kstrtoul(buf, 0, &val))
 258                 return -EINVAL;
 259
 260         /* select the engine to be run */
 261
 262         switch (val) {
 263         case LP55XX_ENGINE_1:
 264         case LP55XX_ENGINE_2:
 265         case LP55XX_ENGINE_3:
 266                 mutex_lock(&chip->lock);
 267                 chip->engine_idx = val;
 268                 ret = lp55xx_request_firmware(chip);
 269                 mutex_unlock(&chip->lock);
 270                 break;
 271         default:
 272                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
 273                 return -EINVAL;
 274         }
 275
 276         if (ret) {
 277                 dev_err(dev, "request firmware err: %d\n", ret);
 278                 return ret;
 279         }
 280
 281         return len;
 282 }
 283
 284 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
 285 {
 286         if (chip->cfg->run_engine)
 287                 chip->cfg->run_engine(chip, start);
 288 }
 289
 290 static ssize_t lp55xx_store_engine_run(struct device *dev,
 291                              struct device_attribute *attr,
 292                              const char *buf, size_t len)
 293 {
 294         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 295         struct lp55xx_chip *chip = led->chip;
 296         unsigned long val;
 297
 298         if (kstrtoul(buf, 0, &val))
 299                 return -EINVAL;
 300
 301         /* run or stop the selected engine */
 302
 303         if (val <= 0) {
 304                 lp55xx_run_engine(chip, false);
 305                 return len;
 306         }
 307
 308         mutex_lock(&chip->lock);
 309         lp55xx_run_engine(chip, true);
 310         mutex_unlock(&chip->lock);
 311
 312         return len;
 313 }
 314
 315 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
 316                    lp55xx_show_engine_select, lp55xx_store_engine_select);
 317 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
 318
 319 static struct attribute *lp55xx_engine_attributes[] = {
 320         &dev_attr_select_engine.attr,
 321         &dev_attr_run_engine.attr,
 322         NULL,
 323 };
 324
 325 static const struct attribute_group lp55xx_engine_attr_group = {
 326         .attrs = lp55xx_engine_attributes,
 327 };
 328
 329 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
 330 {
 331         return i2c_smbus_write_byte_data(chip->cl, reg, val);
 332 }
 333 EXPORT_SYMBOL_GPL(lp55xx_write);
 334
 335 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
 336 {
 337         s32 ret;
 338
 339         ret = i2c_smbus_read_byte_data(chip->cl, reg);
 340         if (ret < 0)
 341                 return ret;
 342
 343         *val = ret;
 344         return 0;
 345 }
 346 EXPORT_SYMBOL_GPL(lp55xx_read);
 347
 348 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
 349 {
 350         int ret;
 351         u8 tmp;
 352
 353         ret = lp55xx_read(chip, reg, &tmp);
 354         if (ret)
 355                 return ret;
 356
 357         tmp &= ~mask;
 358         tmp |= val & mask;
 359
 360         return lp55xx_write(chip, reg, tmp);
 361 }
 362 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 363
 364 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
 365 {
 366         struct clk *clk;
 367         int err;
 368
 369         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
 370         if (IS_ERR(clk))
 371                 goto use_internal_clk;
 372
 373         err = clk_prepare_enable(clk);
 374         if (err)
 375                 goto use_internal_clk;
 376
 377         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
 378                 clk_disable_unprepare(clk);
 379                 goto use_internal_clk;
 380         }
 381
 382         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
 383
 384         chip->clk = clk;
 385         return true;
 386
 387 use_internal_clk:
 388         dev_info(&chip->cl->dev, "internal clock used\n");
 389         return false;
 390 }
 391 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
 392
 393 int lp55xx_init_device(struct lp55xx_chip *chip)
 394 {
 395         struct lp55xx_platform_data *pdata;
 396         struct lp55xx_device_config *cfg;
 397         struct device *dev = &chip->cl->dev;
 398         int ret = 0;
 399
 400         WARN_ON(!chip);
 401
 402         pdata = chip->pdata;
 403         cfg = chip->cfg;
 404
 405         if (!pdata || !cfg)
 406                 return -EINVAL;
 407
 408         if (pdata->setup_resources) {
 409                 ret = pdata->setup_resources();
 410                 if (ret < 0) {
 411                         dev_err(dev, "setup resoure err: %d\n", ret);
 412                         goto err;
 413                 }
 414         }
 415
 416         if (pdata->enable) {
 417                 pdata->enable(0);
 418                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
 419                 pdata->enable(1);
 420                 usleep_range(1000, 2000); /* 500us abs min. */
 421         }
 422
 423         lp55xx_reset_device(chip);
 424
 425         /*
 426          * Exact value is not available. 10 - 20ms
 427          * appears to be enough for reset.
 428          */
 429         usleep_range(10000, 20000);
 430
 431         ret = lp55xx_detect_device(chip);
 432         if (ret) {
 433                 dev_err(dev, "device detection err: %d\n", ret);
 434                 goto err;
 435         }
 436
 437         /* chip specific initialization */
 438         ret = lp55xx_post_init_device(chip);
 439         if (ret) {
 440                 dev_err(dev, "post init device err: %d\n", ret);
 441                 goto err_post_init;
 442         }
 443
 444         return 0;
 445
 446 err_post_init:
 447         lp55xx_deinit_device(chip);
 448 err:
 449         return ret;
 450 }
 451 EXPORT_SYMBOL_GPL(lp55xx_init_device);
 452
 453 void lp55xx_deinit_device(struct lp55xx_chip *chip)
 454 {
 455         struct lp55xx_platform_data *pdata = chip->pdata;
 456
 457         if (chip->clk)
 458                 clk_disable_unprepare(chip->clk);
 459
 460         if (pdata->enable)
 461                 pdata->enable(0);
 462
 463         if (pdata->release_resources)
 464                 pdata->release_resources();
 465 }
 466 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 467
 468 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 469 {
 470         struct lp55xx_platform_data *pdata = chip->pdata;
 471         struct lp55xx_device_config *cfg = chip->cfg;
 472         int num_channels = pdata->num_channels;
 473         struct lp55xx_led *each;
 474         u8 led_current;
 475         int ret;
 476         int i;
 477
 478         if (!cfg->brightness_work_fn) {
 479                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
 480                 return -EINVAL;
 481         }
 482
 483         for (i = 0; i < num_channels; i++) {
 484
 485                 /* do not initialize channels that are not connected */
 486                 if (pdata->led_config[i].led_current == 0)
 487                         continue;
 488
 489                 led_current = pdata->led_config[i].led_current;
 490                 each = led + i;
 491                 ret = lp55xx_init_led(each, chip, i);
 492                 if (ret)
 493                         goto err_init_led;
 494
 495                 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
 496
 497                 chip->num_leds++;
 498                 each->chip = chip;
 499
 500                 /* setting led current at each channel */
 501                 if (cfg->set_led_current)
 502                         cfg->set_led_current(each, led_current);
 503         }
 504
 505         return 0;
 506
 507 err_init_led:
 508         lp55xx_unregister_leds(led, chip);
 509         return ret;
 510 }
 511 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 512
 513 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 514 {
 515         int i;
 516         struct lp55xx_led *each;
 517
 518         for (i = 0; i < chip->num_leds; i++) {
 519                 each = led + i;
 520                 led_classdev_unregister(&each->cdev);
 521                 flush_work(&each->brightness_work);
 522         }
 523 }
 524 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
 525
 526 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
 527 {
 528         struct device *dev = &chip->cl->dev;
 529         struct lp55xx_device_config *cfg = chip->cfg;
 530         int ret;
 531
 532         if (!cfg->run_engine || !cfg->firmware_cb)
 533                 goto dev_specific_attrs;
 534
 535         ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
 536         if (ret)
 537                 return ret;
 538
 539 dev_specific_attrs:
 540         return cfg->dev_attr_group ?
 541                 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
 542 }
 543 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 544
 545 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
 546 {
 547         struct device *dev = &chip->cl->dev;
 548         struct lp55xx_device_config *cfg = chip->cfg;
 549
 550         if (cfg->dev_attr_group)
 551                 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
 552
 553         sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
 554 }
 555 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 556
 557 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 558 MODULE_DESCRIPTION("LP55xx Common Driver");
 559 MODULE_LICENSE("GPL");