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