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 int lp55xx_set_brightness(struct led_classdev *cdev,
 138                              enum led_brightness brightness)
 139 {
 140         struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
 141         struct lp55xx_device_config *cfg = led->chip->cfg;
 142
 143         led->brightness = (u8)brightness;
 144         return cfg->brightness_fn(led);
 145 }
 146
 147 static int lp55xx_init_led(struct lp55xx_led *led,
 148                         struct lp55xx_chip *chip, int chan)
 149 {
 150         struct lp55xx_platform_data *pdata = chip->pdata;
 151         struct lp55xx_device_config *cfg = chip->cfg;
 152         struct device *dev = &chip->cl->dev;
 153         char name[32];
 154         int ret;
 155         int max_channel = cfg->max_channel;
 156
 157         if (chan >= max_channel) {
 158                 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
 159                 return -EINVAL;
 160         }
 161
 162         if (pdata->led_config[chan].led_current == 0)
 163                 return 0;
 164
 165         led->led_current = pdata->led_config[chan].led_current;
 166         led->max_current = pdata->led_config[chan].max_current;
 167         led->chan_nr = pdata->led_config[chan].chan_nr;
 168         led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
 169
 170         if (led->chan_nr >= max_channel) {
 171                 dev_err(dev, "Use channel numbers between 0 and %d\n",
 172                         max_channel - 1);
 173                 return -EINVAL;
 174         }
 175
 176         led->cdev.brightness_set_blocking = lp55xx_set_brightness;
 177         led->cdev.groups = lp55xx_led_groups;
 178
 179         if (pdata->led_config[chan].name) {
 180                 led->cdev.name = pdata->led_config[chan].name;
 181         } else {
 182                 snprintf(name, sizeof(name), "%s:channel%d",
 183                         pdata->label ? : chip->cl->name, chan);
 184                 led->cdev.name = name;
 185         }
 186
 187         ret = led_classdev_register(dev, &led->cdev);
 188         if (ret) {
 189                 dev_err(dev, "led register err: %d\n", ret);
 190                 return ret;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
 197 {
 198         struct lp55xx_chip *chip = context;
 199         struct device *dev = &chip->cl->dev;
 200         enum lp55xx_engine_index idx = chip->engine_idx;
 201
 202         if (!fw) {
 203                 dev_err(dev, "firmware request failed\n");
 204                 return;
 205         }
 206
 207         /* handling firmware data is chip dependent */
 208         mutex_lock(&chip->lock);
 209
 210         chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
 211         chip->fw = fw;
 212         if (chip->cfg->firmware_cb)
 213                 chip->cfg->firmware_cb(chip);
 214
 215         mutex_unlock(&chip->lock);
 216
 217         /* firmware should be released for other channel use */
 218         release_firmware(chip->fw);
 219         chip->fw = NULL;
 220 }
 221
 222 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
 223 {
 224         const char *name = chip->cl->name;
 225         struct device *dev = &chip->cl->dev;
 226
 227         return request_firmware_nowait(THIS_MODULE, false, name, dev,
 228                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
 229 }
 230
 231 static ssize_t lp55xx_show_engine_select(struct device *dev,
 232                             struct device_attribute *attr,
 233                             char *buf)
 234 {
 235         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 236         struct lp55xx_chip *chip = led->chip;
 237
 238         return sprintf(buf, "%d\n", chip->engine_idx);
 239 }
 240
 241 static ssize_t lp55xx_store_engine_select(struct device *dev,
 242                              struct device_attribute *attr,
 243                              const char *buf, size_t len)
 244 {
 245         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 246         struct lp55xx_chip *chip = led->chip;
 247         unsigned long val;
 248         int ret;
 249
 250         if (kstrtoul(buf, 0, &val))
 251                 return -EINVAL;
 252
 253         /* select the engine to be run */
 254
 255         switch (val) {
 256         case LP55XX_ENGINE_1:
 257         case LP55XX_ENGINE_2:
 258         case LP55XX_ENGINE_3:
 259                 mutex_lock(&chip->lock);
 260                 chip->engine_idx = val;
 261                 ret = lp55xx_request_firmware(chip);
 262                 mutex_unlock(&chip->lock);
 263                 break;
 264         default:
 265                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
 266                 return -EINVAL;
 267         }
 268
 269         if (ret) {
 270                 dev_err(dev, "request firmware err: %d\n", ret);
 271                 return ret;
 272         }
 273
 274         return len;
 275 }
 276
 277 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
 278 {
 279         if (chip->cfg->run_engine)
 280                 chip->cfg->run_engine(chip, start);
 281 }
 282
 283 static ssize_t lp55xx_store_engine_run(struct device *dev,
 284                              struct device_attribute *attr,
 285                              const char *buf, size_t len)
 286 {
 287         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 288         struct lp55xx_chip *chip = led->chip;
 289         unsigned long val;
 290
 291         if (kstrtoul(buf, 0, &val))
 292                 return -EINVAL;
 293
 294         /* run or stop the selected engine */
 295
 296         if (val <= 0) {
 297                 lp55xx_run_engine(chip, false);
 298                 return len;
 299         }
 300
 301         mutex_lock(&chip->lock);
 302         lp55xx_run_engine(chip, true);
 303         mutex_unlock(&chip->lock);
 304
 305         return len;
 306 }
 307
 308 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
 309                    lp55xx_show_engine_select, lp55xx_store_engine_select);
 310 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
 311
 312 static struct attribute *lp55xx_engine_attributes[] = {
 313         &dev_attr_select_engine.attr,
 314         &dev_attr_run_engine.attr,
 315         NULL,
 316 };
 317
 318 static const struct attribute_group lp55xx_engine_attr_group = {
 319         .attrs = lp55xx_engine_attributes,
 320 };
 321
 322 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
 323 {
 324         return i2c_smbus_write_byte_data(chip->cl, reg, val);
 325 }
 326 EXPORT_SYMBOL_GPL(lp55xx_write);
 327
 328 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
 329 {
 330         s32 ret;
 331
 332         ret = i2c_smbus_read_byte_data(chip->cl, reg);
 333         if (ret < 0)
 334                 return ret;
 335
 336         *val = ret;
 337         return 0;
 338 }
 339 EXPORT_SYMBOL_GPL(lp55xx_read);
 340
 341 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
 342 {
 343         int ret;
 344         u8 tmp;
 345
 346         ret = lp55xx_read(chip, reg, &tmp);
 347         if (ret)
 348                 return ret;
 349
 350         tmp &= ~mask;
 351         tmp |= val & mask;
 352
 353         return lp55xx_write(chip, reg, tmp);
 354 }
 355 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 356
 357 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
 358 {
 359         struct clk *clk;
 360         int err;
 361
 362         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
 363         if (IS_ERR(clk))
 364                 goto use_internal_clk;
 365
 366         err = clk_prepare_enable(clk);
 367         if (err)
 368                 goto use_internal_clk;
 369
 370         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
 371                 clk_disable_unprepare(clk);
 372                 goto use_internal_clk;
 373         }
 374
 375         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
 376
 377         chip->clk = clk;
 378         return true;
 379
 380 use_internal_clk:
 381         dev_info(&chip->cl->dev, "internal clock used\n");
 382         return false;
 383 }
 384 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
 385
 386 int lp55xx_init_device(struct lp55xx_chip *chip)
 387 {
 388         struct lp55xx_platform_data *pdata;
 389         struct lp55xx_device_config *cfg;
 390         struct device *dev = &chip->cl->dev;
 391         int ret = 0;
 392
 393         WARN_ON(!chip);
 394
 395         pdata = chip->pdata;
 396         cfg = chip->cfg;
 397
 398         if (!pdata || !cfg)
 399                 return -EINVAL;
 400
 401         if (gpio_is_valid(pdata->enable_gpio)) {
 402                 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
 403                                             GPIOF_DIR_OUT, "lp5523_enable");
 404                 if (ret < 0) {
 405                         dev_err(dev, "could not acquire enable gpio (err=%d)\n",
 406                                 ret);
 407                         goto err;
 408                 }
 409
 410                 gpio_set_value(pdata->enable_gpio, 0);
 411                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
 412                 gpio_set_value(pdata->enable_gpio, 1);
 413                 usleep_range(1000, 2000); /* 500us abs min. */
 414         }
 415
 416         lp55xx_reset_device(chip);
 417
 418         /*
 419          * Exact value is not available. 10 - 20ms
 420          * appears to be enough for reset.
 421          */
 422         usleep_range(10000, 20000);
 423
 424         ret = lp55xx_detect_device(chip);
 425         if (ret) {
 426                 dev_err(dev, "device detection err: %d\n", ret);
 427                 goto err;
 428         }
 429
 430         /* chip specific initialization */
 431         ret = lp55xx_post_init_device(chip);
 432         if (ret) {
 433                 dev_err(dev, "post init device err: %d\n", ret);
 434                 goto err_post_init;
 435         }
 436
 437         return 0;
 438
 439 err_post_init:
 440         lp55xx_deinit_device(chip);
 441 err:
 442         return ret;
 443 }
 444 EXPORT_SYMBOL_GPL(lp55xx_init_device);
 445
 446 void lp55xx_deinit_device(struct lp55xx_chip *chip)
 447 {
 448         struct lp55xx_platform_data *pdata = chip->pdata;
 449
 450         if (chip->clk)
 451                 clk_disable_unprepare(chip->clk);
 452
 453         if (gpio_is_valid(pdata->enable_gpio))
 454                 gpio_set_value(pdata->enable_gpio, 0);
 455 }
 456 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 457
 458 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 459 {
 460         struct lp55xx_platform_data *pdata = chip->pdata;
 461         struct lp55xx_device_config *cfg = chip->cfg;
 462         int num_channels = pdata->num_channels;
 463         struct lp55xx_led *each;
 464         u8 led_current;
 465         int ret;
 466         int i;
 467
 468         if (!cfg->brightness_fn) {
 469                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
 470                 return -EINVAL;
 471         }
 472
 473         for (i = 0; i < num_channels; i++) {
 474
 475                 /* do not initialize channels that are not connected */
 476                 if (pdata->led_config[i].led_current == 0)
 477                         continue;
 478
 479                 led_current = pdata->led_config[i].led_current;
 480                 each = led + i;
 481                 ret = lp55xx_init_led(each, chip, i);
 482                 if (ret)
 483                         goto err_init_led;
 484
 485                 chip->num_leds++;
 486                 each->chip = chip;
 487
 488                 /* setting led current at each channel */
 489                 if (cfg->set_led_current)
 490                         cfg->set_led_current(each, led_current);
 491         }
 492
 493         return 0;
 494
 495 err_init_led:
 496         lp55xx_unregister_leds(led, chip);
 497         return ret;
 498 }
 499 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 500
 501 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 502 {
 503         int i;
 504         struct lp55xx_led *each;
 505
 506         for (i = 0; i < chip->num_leds; i++) {
 507                 each = led + i;
 508                 led_classdev_unregister(&each->cdev);
 509         }
 510 }
 511 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
 512
 513 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
 514 {
 515         struct device *dev = &chip->cl->dev;
 516         struct lp55xx_device_config *cfg = chip->cfg;
 517         int ret;
 518
 519         if (!cfg->run_engine || !cfg->firmware_cb)
 520                 goto dev_specific_attrs;
 521
 522         ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
 523         if (ret)
 524                 return ret;
 525
 526 dev_specific_attrs:
 527         return cfg->dev_attr_group ?
 528                 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
 529 }
 530 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 531
 532 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
 533 {
 534         struct device *dev = &chip->cl->dev;
 535         struct lp55xx_device_config *cfg = chip->cfg;
 536
 537         if (cfg->dev_attr_group)
 538                 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
 539
 540         sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
 541 }
 542 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 543
 544 struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
 545                                                       struct device_node *np)
 546 {
 547         struct device_node *child;
 548         struct lp55xx_platform_data *pdata;
 549         struct lp55xx_led_config *cfg;
 550         int num_channels;
 551         int i = 0;
 552
 553         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 554         if (!pdata)
 555                 return ERR_PTR(-ENOMEM);
 556
 557         num_channels = of_get_child_count(np);
 558         if (num_channels == 0) {
 559                 dev_err(dev, "no LED channels\n");
 560                 return ERR_PTR(-EINVAL);
 561         }
 562
 563         cfg = devm_kcalloc(dev, num_channels, sizeof(*cfg), GFP_KERNEL);
 564         if (!cfg)
 565                 return ERR_PTR(-ENOMEM);
 566
 567         pdata->led_config = &cfg[0];
 568         pdata->num_channels = num_channels;
 569
 570         for_each_child_of_node(np, child) {
 571                 cfg[i].chan_nr = i;
 572
 573                 of_property_read_string(child, "chan-name", &cfg[i].name);
 574                 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
 575                 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
 576                 cfg[i].default_trigger =
 577                         of_get_property(child, "linux,default-trigger", NULL);
 578
 579                 i++;
 580         }
 581
 582         of_property_read_string(np, "label", &pdata->label);
 583         of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
 584
 585         pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
 586
 587         /* LP8501 specific */
 588         of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
 589
 590         return pdata;
 591 }
 592 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
 593
 594 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 595 MODULE_DESCRIPTION("LP55xx Common Driver");
 596 MODULE_LICENSE("GPL");