linux/drivers/leds/leds-lp55xx-common.c
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   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
  28static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
  29{
  30        return container_of(cdev, struct lp55xx_led, cdev);
  31}
  32
  33static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
  34{
  35        return cdev_to_lp55xx_led(dev_get_drvdata(dev));
  36}
  37
  38static 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
  48static 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
  71static 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
  81static 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
  90static 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
 114static 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
 123static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
 124                lp55xx_store_current);
 125static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
 126
 127static struct attribute *lp55xx_led_attributes[] = {
 128        &dev_attr_led_current.attr,
 129        &dev_attr_max_current.attr,
 130        NULL,
 131};
 132
 133static struct attribute_group lp55xx_led_attr_group = {
 134        .attrs = lp55xx_led_attributes
 135};
 136
 137static 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
 146static 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
 205static 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
 224out:
 225        /* firmware should be released for other channel use */
 226        release_firmware(chip->fw);
 227}
 228
 229static 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
 238static 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
 248static 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
 284static 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
 290static 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
 315static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
 316                   lp55xx_show_engine_select, lp55xx_store_engine_select);
 317static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
 318
 319static struct attribute *lp55xx_engine_attributes[] = {
 320        &dev_attr_select_engine.attr,
 321        &dev_attr_run_engine.attr,
 322        NULL,
 323};
 324
 325static const struct attribute_group lp55xx_engine_attr_group = {
 326        .attrs = lp55xx_engine_attributes,
 327};
 328
 329int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
 330{
 331        return i2c_smbus_write_byte_data(chip->cl, reg, val);
 332}
 333EXPORT_SYMBOL_GPL(lp55xx_write);
 334
 335int 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}
 346EXPORT_SYMBOL_GPL(lp55xx_read);
 347
 348int 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}
 362EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 363
 364bool 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
 387use_internal_clk:
 388        dev_info(&chip->cl->dev, "internal clock used\n");
 389        return false;
 390}
 391EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
 392
 393int 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
 446err_post_init:
 447        lp55xx_deinit_device(chip);
 448err:
 449        return ret;
 450}
 451EXPORT_SYMBOL_GPL(lp55xx_init_device);
 452
 453void 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}
 466EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 467
 468int 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
 507err_init_led:
 508        lp55xx_unregister_leds(led, chip);
 509        return ret;
 510}
 511EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 512
 513void 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}
 524EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
 525
 526int 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
 539dev_specific_attrs:
 540        return cfg->dev_attr_group ?
 541                sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
 542}
 543EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 544
 545void 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}
 555EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 556
 557MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 558MODULE_DESCRIPTION("LP55xx Common Driver");
 559MODULE_LICENSE("GPL");
 560
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