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_attributes[] = {
 131         &dev_attr_led_current.attr,
 132         &dev_attr_max_current.attr,
 133         NULL,
 134 };
 135
 136 static struct attribute_group lp55xx_led_attr_group = {
 137         .attrs = lp55xx_led_attributes
 138 };
 139
 140 static void lp55xx_set_brightness(struct led_classdev *cdev,
 141                              enum led_brightness brightness)
 142 {
 143         struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
 144
 145         led->brightness = (u8)brightness;
 146         schedule_work(&led->brightness_work);
 147 }
 148
 149 static int lp55xx_init_led(struct lp55xx_led *led,
 150                         struct lp55xx_chip *chip, int chan)
 151 {
 152         struct lp55xx_platform_data *pdata = chip->pdata;
 153         struct lp55xx_device_config *cfg = chip->cfg;
 154         struct device *dev = &chip->cl->dev;
 155         char name[32];
 156         int ret;
 157         int max_channel = cfg->max_channel;
 158
 159         if (chan >= max_channel) {
 160                 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
 161                 return -EINVAL;
 162         }
 163
 164         if (pdata->led_config[chan].led_current == 0)
 165                 return 0;
 166
 167         led->led_current = pdata->led_config[chan].led_current;
 168         led->max_current = pdata->led_config[chan].max_current;
 169         led->chan_nr = pdata->led_config[chan].chan_nr;
 170         led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
 171
 172         if (led->chan_nr >= max_channel) {
 173                 dev_err(dev, "Use channel numbers between 0 and %d\n",
 174                         max_channel - 1);
 175                 return -EINVAL;
 176         }
 177
 178         led->cdev.brightness_set = lp55xx_set_brightness;
 179
 180         if (pdata->led_config[chan].name) {
 181                 led->cdev.name = pdata->led_config[chan].name;
 182         } else {
 183                 snprintf(name, sizeof(name), "%s:channel%d",
 184                         pdata->label ? : chip->cl->name, chan);
 185                 led->cdev.name = name;
 186         }
 187
 188         /*
 189          * register led class device for each channel and
 190          * add device attributes
 191          */
 192
 193         ret = led_classdev_register(dev, &led->cdev);
 194         if (ret) {
 195                 dev_err(dev, "led register err: %d\n", ret);
 196                 return ret;
 197         }
 198
 199         ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group);
 200         if (ret) {
 201                 dev_err(dev, "led sysfs err: %d\n", ret);
 202                 led_classdev_unregister(&led->cdev);
 203                 return ret;
 204         }
 205
 206         return 0;
 207 }
 208
 209 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
 210 {
 211         struct lp55xx_chip *chip = context;
 212         struct device *dev = &chip->cl->dev;
 213         enum lp55xx_engine_index idx = chip->engine_idx;
 214
 215         if (!fw) {
 216                 dev_err(dev, "firmware request failed\n");
 217                 goto out;
 218         }
 219
 220         /* handling firmware data is chip dependent */
 221         mutex_lock(&chip->lock);
 222
 223         chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
 224         chip->fw = fw;
 225         if (chip->cfg->firmware_cb)
 226                 chip->cfg->firmware_cb(chip);
 227
 228         mutex_unlock(&chip->lock);
 229
 230 out:
 231         /* firmware should be released for other channel use */
 232         release_firmware(chip->fw);
 233 }
 234
 235 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
 236 {
 237         const char *name = chip->cl->name;
 238         struct device *dev = &chip->cl->dev;
 239
 240         return request_firmware_nowait(THIS_MODULE, true, name, dev,
 241                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
 242 }
 243
 244 static ssize_t lp55xx_show_engine_select(struct device *dev,
 245                             struct device_attribute *attr,
 246                             char *buf)
 247 {
 248         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 249         struct lp55xx_chip *chip = led->chip;
 250
 251         return sprintf(buf, "%d\n", chip->engine_idx);
 252 }
 253
 254 static ssize_t lp55xx_store_engine_select(struct device *dev,
 255                              struct device_attribute *attr,
 256                              const char *buf, size_t len)
 257 {
 258         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 259         struct lp55xx_chip *chip = led->chip;
 260         unsigned long val;
 261         int ret;
 262
 263         if (kstrtoul(buf, 0, &val))
 264                 return -EINVAL;
 265
 266         /* select the engine to be run */
 267
 268         switch (val) {
 269         case LP55XX_ENGINE_1:
 270         case LP55XX_ENGINE_2:
 271         case LP55XX_ENGINE_3:
 272                 mutex_lock(&chip->lock);
 273                 chip->engine_idx = val;
 274                 ret = lp55xx_request_firmware(chip);
 275                 mutex_unlock(&chip->lock);
 276                 break;
 277         default:
 278                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
 279                 return -EINVAL;
 280         }
 281
 282         if (ret) {
 283                 dev_err(dev, "request firmware err: %d\n", ret);
 284                 return ret;
 285         }
 286
 287         return len;
 288 }
 289
 290 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
 291 {
 292         if (chip->cfg->run_engine)
 293                 chip->cfg->run_engine(chip, start);
 294 }
 295
 296 static ssize_t lp55xx_store_engine_run(struct device *dev,
 297                              struct device_attribute *attr,
 298                              const char *buf, size_t len)
 299 {
 300         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 301         struct lp55xx_chip *chip = led->chip;
 302         unsigned long val;
 303
 304         if (kstrtoul(buf, 0, &val))
 305                 return -EINVAL;
 306
 307         /* run or stop the selected engine */
 308
 309         if (val <= 0) {
 310                 lp55xx_run_engine(chip, false);
 311                 return len;
 312         }
 313
 314         mutex_lock(&chip->lock);
 315         lp55xx_run_engine(chip, true);
 316         mutex_unlock(&chip->lock);
 317
 318         return len;
 319 }
 320
 321 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
 322                    lp55xx_show_engine_select, lp55xx_store_engine_select);
 323 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
 324
 325 static struct attribute *lp55xx_engine_attributes[] = {
 326         &dev_attr_select_engine.attr,
 327         &dev_attr_run_engine.attr,
 328         NULL,
 329 };
 330
 331 static const struct attribute_group lp55xx_engine_attr_group = {
 332         .attrs = lp55xx_engine_attributes,
 333 };
 334
 335 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
 336 {
 337         return i2c_smbus_write_byte_data(chip->cl, reg, val);
 338 }
 339 EXPORT_SYMBOL_GPL(lp55xx_write);
 340
 341 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
 342 {
 343         s32 ret;
 344
 345         ret = i2c_smbus_read_byte_data(chip->cl, reg);
 346         if (ret < 0)
 347                 return ret;
 348
 349         *val = ret;
 350         return 0;
 351 }
 352 EXPORT_SYMBOL_GPL(lp55xx_read);
 353
 354 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
 355 {
 356         int ret;
 357         u8 tmp;
 358
 359         ret = lp55xx_read(chip, reg, &tmp);
 360         if (ret)
 361                 return ret;
 362
 363         tmp &= ~mask;
 364         tmp |= val & mask;
 365
 366         return lp55xx_write(chip, reg, tmp);
 367 }
 368 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 369
 370 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
 371 {
 372         struct clk *clk;
 373         int err;
 374
 375         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
 376         if (IS_ERR(clk))
 377                 goto use_internal_clk;
 378
 379         err = clk_prepare_enable(clk);
 380         if (err)
 381                 goto use_internal_clk;
 382
 383         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
 384                 clk_disable_unprepare(clk);
 385                 goto use_internal_clk;
 386         }
 387
 388         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
 389
 390         chip->clk = clk;
 391         return true;
 392
 393 use_internal_clk:
 394         dev_info(&chip->cl->dev, "internal clock used\n");
 395         return false;
 396 }
 397 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
 398
 399 int lp55xx_init_device(struct lp55xx_chip *chip)
 400 {
 401         struct lp55xx_platform_data *pdata;
 402         struct lp55xx_device_config *cfg;
 403         struct device *dev = &chip->cl->dev;
 404         int ret = 0;
 405
 406         WARN_ON(!chip);
 407
 408         pdata = chip->pdata;
 409         cfg = chip->cfg;
 410
 411         if (!pdata || !cfg)
 412                 return -EINVAL;
 413
 414         if (gpio_is_valid(pdata->enable_gpio)) {
 415                 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
 416                                             GPIOF_DIR_OUT, "lp5523_enable");
 417                 if (ret < 0) {
 418                         dev_err(dev, "could not acquire enable gpio (err=%d)\n",
 419                                 ret);
 420                         goto err;
 421                 }
 422
 423                 gpio_set_value(pdata->enable_gpio, 0);
 424                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
 425                 gpio_set_value(pdata->enable_gpio, 1);
 426                 usleep_range(1000, 2000); /* 500us abs min. */
 427         }
 428
 429         lp55xx_reset_device(chip);
 430
 431         /*
 432          * Exact value is not available. 10 - 20ms
 433          * appears to be enough for reset.
 434          */
 435         usleep_range(10000, 20000);
 436
 437         ret = lp55xx_detect_device(chip);
 438         if (ret) {
 439                 dev_err(dev, "device detection err: %d\n", ret);
 440                 goto err;
 441         }
 442
 443         /* chip specific initialization */
 444         ret = lp55xx_post_init_device(chip);
 445         if (ret) {
 446                 dev_err(dev, "post init device err: %d\n", ret);
 447                 goto err_post_init;
 448         }
 449
 450         return 0;
 451
 452 err_post_init:
 453         lp55xx_deinit_device(chip);
 454 err:
 455         return ret;
 456 }
 457 EXPORT_SYMBOL_GPL(lp55xx_init_device);
 458
 459 void lp55xx_deinit_device(struct lp55xx_chip *chip)
 460 {
 461         struct lp55xx_platform_data *pdata = chip->pdata;
 462
 463         if (chip->clk)
 464                 clk_disable_unprepare(chip->clk);
 465
 466         if (gpio_is_valid(pdata->enable_gpio))
 467                 gpio_set_value(pdata->enable_gpio, 0);
 468 }
 469 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 470
 471 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 472 {
 473         struct lp55xx_platform_data *pdata = chip->pdata;
 474         struct lp55xx_device_config *cfg = chip->cfg;
 475         int num_channels = pdata->num_channels;
 476         struct lp55xx_led *each;
 477         u8 led_current;
 478         int ret;
 479         int i;
 480
 481         if (!cfg->brightness_work_fn) {
 482                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
 483                 return -EINVAL;
 484         }
 485
 486         for (i = 0; i < num_channels; i++) {
 487
 488                 /* do not initialize channels that are not connected */
 489                 if (pdata->led_config[i].led_current == 0)
 490                         continue;
 491
 492                 led_current = pdata->led_config[i].led_current;
 493                 each = led + i;
 494                 ret = lp55xx_init_led(each, chip, i);
 495                 if (ret)
 496                         goto err_init_led;
 497
 498                 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
 499
 500                 chip->num_leds++;
 501                 each->chip = chip;
 502
 503                 /* setting led current at each channel */
 504                 if (cfg->set_led_current)
 505                         cfg->set_led_current(each, led_current);
 506         }
 507
 508         return 0;
 509
 510 err_init_led:
 511         lp55xx_unregister_leds(led, chip);
 512         return ret;
 513 }
 514 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 515
 516 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 517 {
 518         int i;
 519         struct lp55xx_led *each;
 520
 521         for (i = 0; i < chip->num_leds; i++) {
 522                 each = led + i;
 523                 led_classdev_unregister(&each->cdev);
 524                 flush_work(&each->brightness_work);
 525         }
 526 }
 527 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
 528
 529 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
 530 {
 531         struct device *dev = &chip->cl->dev;
 532         struct lp55xx_device_config *cfg = chip->cfg;
 533         int ret;
 534
 535         if (!cfg->run_engine || !cfg->firmware_cb)
 536                 goto dev_specific_attrs;
 537
 538         ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
 539         if (ret)
 540                 return ret;
 541
 542 dev_specific_attrs:
 543         return cfg->dev_attr_group ?
 544                 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
 545 }
 546 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 547
 548 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
 549 {
 550         struct device *dev = &chip->cl->dev;
 551         struct lp55xx_device_config *cfg = chip->cfg;
 552
 553         if (cfg->dev_attr_group)
 554                 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
 555
 556         sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
 557 }
 558 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 559
 560 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
 561 {
 562         struct device_node *child;
 563         struct lp55xx_platform_data *pdata;
 564         struct lp55xx_led_config *cfg;
 565         int num_channels;
 566         int i = 0;
 567
 568         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 569         if (!pdata)
 570                 return -ENOMEM;
 571
 572         num_channels = of_get_child_count(np);
 573         if (num_channels == 0) {
 574                 dev_err(dev, "no LED channels\n");
 575                 return -EINVAL;
 576         }
 577
 578         cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
 579         if (!cfg)
 580                 return -ENOMEM;
 581
 582         pdata->led_config = &cfg[0];
 583         pdata->num_channels = num_channels;
 584
 585         for_each_child_of_node(np, child) {
 586                 cfg[i].chan_nr = i;
 587
 588                 of_property_read_string(child, "chan-name", &cfg[i].name);
 589                 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
 590                 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
 591                 cfg[i].default_trigger =
 592                         of_get_property(child, "linux,default-trigger", NULL);
 593
 594                 i++;
 595         }
 596
 597         of_property_read_string(np, "label", &pdata->label);
 598         of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
 599
 600         pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
 601
 602         /* LP8501 specific */
 603         of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
 604
 605         dev->platform_data = pdata;
 606
 607         return 0;
 608 }
 609 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
 610
 611 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 612 MODULE_DESCRIPTION("LP55xx Common Driver");
 613 MODULE_LICENSE("GPL");