kernel/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 #include <linux/slab.h>
  23 #include <linux/gpio.h>
  24 #include <linux/of_gpio.h>
  25
  26 #include "leds-lp55xx-common.h"
  27
  28 /* External clock rate */
  29 #define LP55XX_CLK_32K                  32768
  30
  31 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
  32 {
  33         return container_of(cdev, struct lp55xx_led, cdev);
  34 }
  35
  36 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
  37 {
  38         return cdev_to_lp55xx_led(dev_get_drvdata(dev));
  39 }
  40
  41 static void lp55xx_reset_device(struct lp55xx_chip *chip)
  42 {
  43         struct lp55xx_device_config *cfg = chip->cfg;
  44         u8 addr = cfg->reset.addr;
  45         u8 val  = cfg->reset.val;
  46
  47         /* no error checking here because no ACK from the device after reset */
  48         lp55xx_write(chip, addr, val);
  49 }
  50
  51 static int lp55xx_detect_device(struct lp55xx_chip *chip)
  52 {
  53         struct lp55xx_device_config *cfg = chip->cfg;
  54         u8 addr = cfg->enable.addr;
  55         u8 val  = cfg->enable.val;
  56         int ret;
  57
  58         ret = lp55xx_write(chip, addr, val);
  59         if (ret)
  60                 return ret;
  61
  62         usleep_range(1000, 2000);
  63
  64         ret = lp55xx_read(chip, addr, &val);
  65         if (ret)
  66                 return ret;
  67
  68         if (val != cfg->enable.val)
  69                 return -ENODEV;
  70
  71         return 0;
  72 }
  73
  74 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
  75 {
  76         struct lp55xx_device_config *cfg = chip->cfg;
  77
  78         if (!cfg->post_init_device)
  79                 return 0;
  80
  81         return cfg->post_init_device(chip);
  82 }
  83
  84 static ssize_t lp55xx_show_current(struct device *dev,
  85                             struct device_attribute *attr,
  86                             char *buf)
  87 {
  88         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
  89
  90         return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
  91 }
  92
  93 static ssize_t lp55xx_store_current(struct device *dev,
  94                              struct device_attribute *attr,
  95                              const char *buf, size_t len)
  96 {
  97         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
  98         struct lp55xx_chip *chip = led->chip;
  99         unsigned long curr;
 100
 101         if (kstrtoul(buf, 0, &curr))
 102                 return -EINVAL;
 103
 104         if (curr > led->max_current)
 105                 return -EINVAL;
 106
 107         if (!chip->cfg->set_led_current)
 108                 return len;
 109
 110         mutex_lock(&chip->lock);
 111         chip->cfg->set_led_current(led, (u8)curr);
 112         mutex_unlock(&chip->lock);
 113
 114         return len;
 115 }
 116
 117 static ssize_t lp55xx_show_max_current(struct device *dev,
 118                             struct device_attribute *attr,
 119                             char *buf)
 120 {
 121         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
 122
 123         return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
 124 }
 125
 126 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
 127                 lp55xx_store_current);
 128 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
 129
 130 static struct attribute *lp55xx_led_attrs[] = {
 131         &dev_attr_led_current.attr,
 132         &dev_attr_max_current.attr,
 133         NULL,
 134 };
 135 ATTRIBUTE_GROUPS(lp55xx_led);
 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         led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
 168
 169         if (led->chan_nr >= max_channel) {
 170                 dev_err(dev, "Use channel numbers between 0 and %d\n",
 171                         max_channel - 1);
 172                 return -EINVAL;
 173         }
 174
 175         led->cdev.brightness_set = lp55xx_set_brightness;
 176         led->cdev.groups = lp55xx_led_groups;
 177
 178         if (pdata->led_config[chan].name) {
 179                 led->cdev.name = pdata->led_config[chan].name;
 180         } else {
 181                 snprintf(name, sizeof(name), "%s:channel%d",
 182                         pdata->label ? : chip->cl->name, chan);
 183                 led->cdev.name = name;
 184         }
 185
 186         ret = led_classdev_register(dev, &led->cdev);
 187         if (ret) {
 188                 dev_err(dev, "led register err: %d\n", ret);
 189                 return ret;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
 196 {
 197         struct lp55xx_chip *chip = context;
 198         struct device *dev = &chip->cl->dev;
 199         enum lp55xx_engine_index idx = chip->engine_idx;
 200
 201         if (!fw) {
 202                 dev_err(dev, "firmware request failed\n");
 203                 goto out;
 204         }
 205
 206         /* handling firmware data is chip dependent */
 207         mutex_lock(&chip->lock);
 208
 209         chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
 210         chip->fw = fw;
 211         if (chip->cfg->firmware_cb)
 212                 chip->cfg->firmware_cb(chip);
 213
 214         mutex_unlock(&chip->lock);
 215
 216 out:
 217         /* firmware should be released for other channel use */
 218         release_firmware(chip->fw);
 219 }
 220
 221 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
 222 {
 223         const char *name = chip->cl->name;
 224         struct device *dev = &chip->cl->dev;
 225
 226         return request_firmware_nowait(THIS_MODULE, true, name, dev,
 227                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
 228 }
 229
 230 static ssize_t lp55xx_show_engine_select(struct device *dev,
 231                             struct device_attribute *attr,
 232                             char *buf)
 233 {
 234         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 235         struct lp55xx_chip *chip = led->chip;
 236
 237         return sprintf(buf, "%d\n", chip->engine_idx);
 238 }
 239
 240 static ssize_t lp55xx_store_engine_select(struct device *dev,
 241                              struct device_attribute *attr,
 242                              const char *buf, size_t len)
 243 {
 244         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 245         struct lp55xx_chip *chip = led->chip;
 246         unsigned long val;
 247         int ret;
 248
 249         if (kstrtoul(buf, 0, &val))
 250                 return -EINVAL;
 251
 252         /* select the engine to be run */
 253
 254         switch (val) {
 255         case LP55XX_ENGINE_1:
 256         case LP55XX_ENGINE_2:
 257         case LP55XX_ENGINE_3:
 258                 mutex_lock(&chip->lock);
 259                 chip->engine_idx = val;
 260                 ret = lp55xx_request_firmware(chip);
 261                 mutex_unlock(&chip->lock);
 262                 break;
 263         default:
 264                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
 265                 return -EINVAL;
 266         }
 267
 268         if (ret) {
 269                 dev_err(dev, "request firmware err: %d\n", ret);
 270                 return ret;
 271         }
 272
 273         return len;
 274 }
 275
 276 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
 277 {
 278         if (chip->cfg->run_engine)
 279                 chip->cfg->run_engine(chip, start);
 280 }
 281
 282 static ssize_t lp55xx_store_engine_run(struct device *dev,
 283                              struct device_attribute *attr,
 284                              const char *buf, size_t len)
 285 {
 286         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 287         struct lp55xx_chip *chip = led->chip;
 288         unsigned long val;
 289
 290         if (kstrtoul(buf, 0, &val))
 291                 return -EINVAL;
 292
 293         /* run or stop the selected engine */
 294
 295         if (val <= 0) {
 296                 lp55xx_run_engine(chip, false);
 297                 return len;
 298         }
 299
 300         mutex_lock(&chip->lock);
 301         lp55xx_run_engine(chip, true);
 302         mutex_unlock(&chip->lock);
 303
 304         return len;
 305 }
 306
 307 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
 308                    lp55xx_show_engine_select, lp55xx_store_engine_select);
 309 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
 310
 311 static struct attribute *lp55xx_engine_attributes[] = {
 312         &dev_attr_select_engine.attr,
 313         &dev_attr_run_engine.attr,
 314         NULL,
 315 };
 316
 317 static const struct attribute_group lp55xx_engine_attr_group = {
 318         .attrs = lp55xx_engine_attributes,
 319 };
 320
 321 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
 322 {
 323         return i2c_smbus_write_byte_data(chip->cl, reg, val);
 324 }
 325 EXPORT_SYMBOL_GPL(lp55xx_write);
 326
 327 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
 328 {
 329         s32 ret;
 330
 331         ret = i2c_smbus_read_byte_data(chip->cl, reg);
 332         if (ret < 0)
 333                 return ret;
 334
 335         *val = ret;
 336         return 0;
 337 }
 338 EXPORT_SYMBOL_GPL(lp55xx_read);
 339
 340 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
 341 {
 342         int ret;
 343         u8 tmp;
 344
 345         ret = lp55xx_read(chip, reg, &tmp);
 346         if (ret)
 347                 return ret;
 348
 349         tmp &= ~mask;
 350         tmp |= val & mask;
 351
 352         return lp55xx_write(chip, reg, tmp);
 353 }
 354 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 355
 356 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
 357 {
 358         struct clk *clk;
 359         int err;
 360
 361         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
 362         if (IS_ERR(clk))
 363                 goto use_internal_clk;
 364
 365         err = clk_prepare_enable(clk);
 366         if (err)
 367                 goto use_internal_clk;
 368
 369         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
 370                 clk_disable_unprepare(clk);
 371                 goto use_internal_clk;
 372         }
 373
 374         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
 375
 376         chip->clk = clk;
 377         return true;
 378
 379 use_internal_clk:
 380         dev_info(&chip->cl->dev, "internal clock used\n");
 381         return false;
 382 }
 383 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
 384
 385 int lp55xx_init_device(struct lp55xx_chip *chip)
 386 {
 387         struct lp55xx_platform_data *pdata;
 388         struct lp55xx_device_config *cfg;
 389         struct device *dev = &chip->cl->dev;
 390         int ret = 0;
 391
 392         WARN_ON(!chip);
 393
 394         pdata = chip->pdata;
 395         cfg = chip->cfg;
 396
 397         if (!pdata || !cfg)
 398                 return -EINVAL;
 399
 400         if (gpio_is_valid(pdata->enable_gpio)) {
 401                 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
 402                                             GPIOF_DIR_OUT, "lp5523_enable");
 403                 if (ret < 0) {
 404                         dev_err(dev, "could not acquire enable gpio (err=%d)\n",
 405                                 ret);
 406                         goto err;
 407                 }
 408
 409                 gpio_set_value(pdata->enable_gpio, 0);
 410                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
 411                 gpio_set_value(pdata->enable_gpio, 1);
 412                 usleep_range(1000, 2000); /* 500us abs min. */
 413         }
 414
 415         lp55xx_reset_device(chip);
 416
 417         /*
 418          * Exact value is not available. 10 - 20ms
 419          * appears to be enough for reset.
 420          */
 421         usleep_range(10000, 20000);
 422
 423         ret = lp55xx_detect_device(chip);
 424         if (ret) {
 425                 dev_err(dev, "device detection err: %d\n", ret);
 426                 goto err;
 427         }
 428
 429         /* chip specific initialization */
 430         ret = lp55xx_post_init_device(chip);
 431         if (ret) {
 432                 dev_err(dev, "post init device err: %d\n", ret);
 433                 goto err_post_init;
 434         }
 435
 436         return 0;
 437
 438 err_post_init:
 439         lp55xx_deinit_device(chip);
 440 err:
 441         return ret;
 442 }
 443 EXPORT_SYMBOL_GPL(lp55xx_init_device);
 444
 445 void lp55xx_deinit_device(struct lp55xx_chip *chip)
 446 {
 447         struct lp55xx_platform_data *pdata = chip->pdata;
 448
 449         if (chip->clk)
 450                 clk_disable_unprepare(chip->clk);
 451
 452         if (gpio_is_valid(pdata->enable_gpio))
 453                 gpio_set_value(pdata->enable_gpio, 0);
 454 }
 455 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 456
 457 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 458 {
 459         struct lp55xx_platform_data *pdata = chip->pdata;
 460         struct lp55xx_device_config *cfg = chip->cfg;
 461         int num_channels = pdata->num_channels;
 462         struct lp55xx_led *each;
 463         u8 led_current;
 464         int ret;
 465         int i;
 466
 467         if (!cfg->brightness_work_fn) {
 468                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
 469                 return -EINVAL;
 470         }
 471
 472         for (i = 0; i < num_channels; i++) {
 473
 474                 /* do not initialize channels that are not connected */
 475                 if (pdata->led_config[i].led_current == 0)
 476                         continue;
 477
 478                 led_current = pdata->led_config[i].led_current;
 479                 each = led + i;
 480                 ret = lp55xx_init_led(each, chip, i);
 481                 if (ret)
 482                         goto err_init_led;
 483
 484                 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
 485
 486                 chip->num_leds++;
 487                 each->chip = chip;
 488
 489                 /* setting led current at each channel */
 490                 if (cfg->set_led_current)
 491                         cfg->set_led_current(each, led_current);
 492         }
 493
 494         return 0;
 495
 496 err_init_led:
 497         lp55xx_unregister_leds(led, chip);
 498         return ret;
 499 }
 500 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 501
 502 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 503 {
 504         int i;
 505         struct lp55xx_led *each;
 506
 507         for (i = 0; i < chip->num_leds; i++) {
 508                 each = led + i;
 509                 led_classdev_unregister(&each->cdev);
 510                 flush_work(&each->brightness_work);
 511         }
 512 }
 513 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
 514
 515 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
 516 {
 517         struct device *dev = &chip->cl->dev;
 518         struct lp55xx_device_config *cfg = chip->cfg;
 519         int ret;
 520
 521         if (!cfg->run_engine || !cfg->firmware_cb)
 522                 goto dev_specific_attrs;
 523
 524         ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
 525         if (ret)
 526                 return ret;
 527
 528 dev_specific_attrs:
 529         return cfg->dev_attr_group ?
 530                 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
 531 }
 532 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 533
 534 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
 535 {
 536         struct device *dev = &chip->cl->dev;
 537         struct lp55xx_device_config *cfg = chip->cfg;
 538
 539         if (cfg->dev_attr_group)
 540                 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
 541
 542         sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
 543 }
 544 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 545
 546 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
 547 {
 548         struct device_node *child;
 549         struct lp55xx_platform_data *pdata;
 550         struct lp55xx_led_config *cfg;
 551         int num_channels;
 552         int i = 0;
 553
 554         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 555         if (!pdata)
 556                 return -ENOMEM;
 557
 558         num_channels = of_get_child_count(np);
 559         if (num_channels == 0) {
 560                 dev_err(dev, "no LED channels\n");
 561                 return -EINVAL;
 562         }
 563
 564         cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
 565         if (!cfg)
 566                 return -ENOMEM;
 567
 568         pdata->led_config = &cfg[0];
 569         pdata->num_channels = num_channels;
 570
 571         for_each_child_of_node(np, child) {
 572                 cfg[i].chan_nr = i;
 573
 574                 of_property_read_string(child, "chan-name", &cfg[i].name);
 575                 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
 576                 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
 577                 cfg[i].default_trigger =
 578                         of_get_property(child, "linux,default-trigger", NULL);
 579
 580                 i++;
 581         }
 582
 583         of_property_read_string(np, "label", &pdata->label);
 584         of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
 585
 586         pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
 587
 588         /* LP8501 specific */
 589         of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
 590
 591         dev->platform_data = pdata;
 592
 593         return 0;
 594 }
 595 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
 596
 597 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 598 MODULE_DESCRIPTION("LP55xx Common Driver");
 599 MODULE_LICENSE("GPL");