linux/drivers/leds/leds-lp5523.c
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   1/*
   2 * lp5523.c - LP5523 LED Driver
   3 *
   4 * Copyright (C) 2010 Nokia Corporation
   5 * Copyright (C) 2012 Texas Instruments
   6 *
   7 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
   8 *          Milo(Woogyom) Kim <milo.kim@ti.com>
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public License
  12 * version 2 as published by the Free Software Foundation.
  13 *
  14 * This program is distributed in the hope that it will be useful, but
  15 * WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 * General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  22 * 02110-1301 USA
  23 */
  24
  25#include <linux/delay.h>
  26#include <linux/firmware.h>
  27#include <linux/i2c.h>
  28#include <linux/init.h>
  29#include <linux/leds.h>
  30#include <linux/module.h>
  31#include <linux/mutex.h>
  32#include <linux/platform_data/leds-lp55xx.h>
  33#include <linux/slab.h>
  34
  35#include "leds-lp55xx-common.h"
  36
  37#define LP5523_PROGRAM_LENGTH           32
  38#define LP5523_MAX_LEDS                 9
  39
  40/* Registers */
  41#define LP5523_REG_ENABLE               0x00
  42#define LP5523_REG_OP_MODE              0x01
  43#define LP5523_REG_ENABLE_LEDS_MSB      0x04
  44#define LP5523_REG_ENABLE_LEDS_LSB      0x05
  45#define LP5523_REG_LED_PWM_BASE         0x16
  46#define LP5523_REG_LED_CURRENT_BASE     0x26
  47#define LP5523_REG_CONFIG               0x36
  48#define LP5523_REG_STATUS               0x3A
  49#define LP5523_REG_RESET                0x3D
  50#define LP5523_REG_LED_TEST_CTRL        0x41
  51#define LP5523_REG_LED_TEST_ADC         0x42
  52#define LP5523_REG_PROG_PAGE_SEL        0x4F
  53#define LP5523_REG_PROG_MEM             0x50
  54
  55/* Bit description in registers */
  56#define LP5523_ENABLE                   0x40
  57#define LP5523_AUTO_INC                 0x40
  58#define LP5523_PWR_SAVE                 0x20
  59#define LP5523_PWM_PWR_SAVE             0x04
  60#define LP5523_CP_AUTO                  0x18
  61#define LP5523_AUTO_CLK                 0x02
  62
  63#define LP5523_EN_LEDTEST               0x80
  64#define LP5523_LEDTEST_DONE             0x80
  65#define LP5523_RESET                    0xFF
  66#define LP5523_ADC_SHORTCIRC_LIM        80
  67#define LP5523_EXT_CLK_USED             0x08
  68
  69/* Memory Page Selection */
  70#define LP5523_PAGE_ENG1                0
  71#define LP5523_PAGE_ENG2                1
  72#define LP5523_PAGE_ENG3                2
  73
  74/* Program Memory Operations */
  75#define LP5523_MODE_ENG1_M              0x30    /* Operation Mode Register */
  76#define LP5523_MODE_ENG2_M              0x0C
  77#define LP5523_MODE_ENG3_M              0x03
  78#define LP5523_LOAD_ENG1                0x10
  79#define LP5523_LOAD_ENG2                0x04
  80#define LP5523_LOAD_ENG3                0x01
  81
  82#define LP5523_ENG1_IS_LOADING(mode)    \
  83        ((mode & LP5523_MODE_ENG1_M) == LP5523_LOAD_ENG1)
  84#define LP5523_ENG2_IS_LOADING(mode)    \
  85        ((mode & LP5523_MODE_ENG2_M) == LP5523_LOAD_ENG2)
  86#define LP5523_ENG3_IS_LOADING(mode)    \
  87        ((mode & LP5523_MODE_ENG3_M) == LP5523_LOAD_ENG3)
  88
  89#define LP5523_EXEC_ENG1_M              0x30    /* Enable Register */
  90#define LP5523_EXEC_ENG2_M              0x0C
  91#define LP5523_EXEC_ENG3_M              0x03
  92#define LP5523_EXEC_M                   0x3F
  93#define LP5523_RUN_ENG1                 0x20
  94#define LP5523_RUN_ENG2                 0x08
  95#define LP5523_RUN_ENG3                 0x02
  96
  97enum lp5523_chip_id {
  98        LP5523,
  99        LP55231,
 100};
 101
 102static inline void lp5523_wait_opmode_done(void)
 103{
 104        usleep_range(1000, 2000);
 105}
 106
 107static void lp5523_set_led_current(struct lp55xx_led *led, u8 led_current)
 108{
 109        led->led_current = led_current;
 110        lp55xx_write(led->chip, LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
 111                led_current);
 112}
 113
 114static int lp5523_post_init_device(struct lp55xx_chip *chip)
 115{
 116        int ret;
 117
 118        ret = lp55xx_write(chip, LP5523_REG_ENABLE, LP5523_ENABLE);
 119        if (ret)
 120                return ret;
 121
 122        /* Chip startup time is 500 us, 1 - 2 ms gives some margin */
 123        usleep_range(1000, 2000);
 124
 125        ret = lp55xx_write(chip, LP5523_REG_CONFIG,
 126                            LP5523_AUTO_INC | LP5523_PWR_SAVE |
 127                            LP5523_CP_AUTO | LP5523_AUTO_CLK |
 128                            LP5523_PWM_PWR_SAVE);
 129        if (ret)
 130                return ret;
 131
 132        /* turn on all leds */
 133        ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
 134        if (ret)
 135                return ret;
 136
 137        return lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
 138}
 139
 140static void lp5523_load_engine(struct lp55xx_chip *chip)
 141{
 142        enum lp55xx_engine_index idx = chip->engine_idx;
 143        u8 mask[] = {
 144                [LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
 145                [LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
 146                [LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
 147        };
 148
 149        u8 val[] = {
 150                [LP55XX_ENGINE_1] = LP5523_LOAD_ENG1,
 151                [LP55XX_ENGINE_2] = LP5523_LOAD_ENG2,
 152                [LP55XX_ENGINE_3] = LP5523_LOAD_ENG3,
 153        };
 154
 155        u8 page_sel[] = {
 156                [LP55XX_ENGINE_1] = LP5523_PAGE_ENG1,
 157                [LP55XX_ENGINE_2] = LP5523_PAGE_ENG2,
 158                [LP55XX_ENGINE_3] = LP5523_PAGE_ENG3,
 159        };
 160
 161        lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], val[idx]);
 162
 163        lp5523_wait_opmode_done();
 164
 165        lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, page_sel[idx]);
 166}
 167
 168static void lp5523_stop_engine(struct lp55xx_chip *chip)
 169{
 170        lp55xx_write(chip, LP5523_REG_OP_MODE, 0);
 171        lp5523_wait_opmode_done();
 172}
 173
 174static void lp5523_turn_off_channels(struct lp55xx_chip *chip)
 175{
 176        int i;
 177
 178        for (i = 0; i < LP5523_MAX_LEDS; i++)
 179                lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0);
 180}
 181
 182static void lp5523_run_engine(struct lp55xx_chip *chip, bool start)
 183{
 184        int ret;
 185        u8 mode;
 186        u8 exec;
 187
 188        /* stop engine */
 189        if (!start) {
 190                lp5523_stop_engine(chip);
 191                lp5523_turn_off_channels(chip);
 192                return;
 193        }
 194
 195        /*
 196         * To run the engine,
 197         * operation mode and enable register should updated at the same time
 198         */
 199
 200        ret = lp55xx_read(chip, LP5523_REG_OP_MODE, &mode);
 201        if (ret)
 202                return;
 203
 204        ret = lp55xx_read(chip, LP5523_REG_ENABLE, &exec);
 205        if (ret)
 206                return;
 207
 208        /* change operation mode to RUN only when each engine is loading */
 209        if (LP5523_ENG1_IS_LOADING(mode)) {
 210                mode = (mode & ~LP5523_MODE_ENG1_M) | LP5523_RUN_ENG1;
 211                exec = (exec & ~LP5523_EXEC_ENG1_M) | LP5523_RUN_ENG1;
 212        }
 213
 214        if (LP5523_ENG2_IS_LOADING(mode)) {
 215                mode = (mode & ~LP5523_MODE_ENG2_M) | LP5523_RUN_ENG2;
 216                exec = (exec & ~LP5523_EXEC_ENG2_M) | LP5523_RUN_ENG2;
 217        }
 218
 219        if (LP5523_ENG3_IS_LOADING(mode)) {
 220                mode = (mode & ~LP5523_MODE_ENG3_M) | LP5523_RUN_ENG3;
 221                exec = (exec & ~LP5523_EXEC_ENG3_M) | LP5523_RUN_ENG3;
 222        }
 223
 224        lp55xx_write(chip, LP5523_REG_OP_MODE, mode);
 225        lp5523_wait_opmode_done();
 226
 227        lp55xx_update_bits(chip, LP5523_REG_ENABLE, LP5523_EXEC_M, exec);
 228}
 229
 230static int lp5523_update_program_memory(struct lp55xx_chip *chip,
 231                                        const u8 *data, size_t size)
 232{
 233        u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
 234        unsigned cmd;
 235        char c[3];
 236        int update_size;
 237        int nrchars;
 238        int offset = 0;
 239        int ret;
 240        int i;
 241
 242        /* clear program memory before updating */
 243        for (i = 0; i < LP5523_PROGRAM_LENGTH; i++)
 244                lp55xx_write(chip, LP5523_REG_PROG_MEM + i, 0);
 245
 246        i = 0;
 247        while ((offset < size - 1) && (i < LP5523_PROGRAM_LENGTH)) {
 248                /* separate sscanfs because length is working only for %s */
 249                ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 250                if (ret != 1)
 251                        goto err;
 252
 253                ret = sscanf(c, "%2x", &cmd);
 254                if (ret != 1)
 255                        goto err;
 256
 257                pattern[i] = (u8)cmd;
 258                offset += nrchars;
 259                i++;
 260        }
 261
 262        /* Each instruction is 16bit long. Check that length is even */
 263        if (i % 2)
 264                goto err;
 265
 266        update_size = i;
 267        for (i = 0; i < update_size; i++)
 268                lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
 269
 270        return 0;
 271
 272err:
 273        dev_err(&chip->cl->dev, "wrong pattern format\n");
 274        return -EINVAL;
 275}
 276
 277static void lp5523_firmware_loaded(struct lp55xx_chip *chip)
 278{
 279        const struct firmware *fw = chip->fw;
 280
 281        if (fw->size > LP5523_PROGRAM_LENGTH) {
 282                dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 283                        fw->size);
 284                return;
 285        }
 286
 287        /*
 288         * Program momery sequence
 289         *  1) set engine mode to "LOAD"
 290         *  2) write firmware data into program memory
 291         */
 292
 293        lp5523_load_engine(chip);
 294        lp5523_update_program_memory(chip, fw->data, fw->size);
 295}
 296
 297static ssize_t lp5523_selftest(struct device *dev,
 298                               struct device_attribute *attr,
 299                               char *buf)
 300{
 301        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 302        struct lp55xx_chip *chip = led->chip;
 303        struct lp55xx_platform_data *pdata = chip->pdata;
 304        int i, ret, pos = 0;
 305        u8 status, adc, vdd;
 306
 307        mutex_lock(&chip->lock);
 308
 309        ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
 310        if (ret < 0)
 311                goto fail;
 312
 313        /* Check that ext clock is really in use if requested */
 314        if (pdata->clock_mode == LP55XX_CLOCK_EXT) {
 315                if  ((status & LP5523_EXT_CLK_USED) == 0)
 316                        goto fail;
 317        }
 318
 319        /* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
 320        lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16);
 321        usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
 322        ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
 323        if (ret < 0)
 324                goto fail;
 325
 326        if (!(status & LP5523_LEDTEST_DONE))
 327                usleep_range(3000, 6000); /* Was not ready. Wait little bit */
 328
 329        ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &vdd);
 330        if (ret < 0)
 331                goto fail;
 332
 333        vdd--;  /* There may be some fluctuation in measurement */
 334
 335        for (i = 0; i < LP5523_MAX_LEDS; i++) {
 336                /* Skip non-existing channels */
 337                if (pdata->led_config[i].led_current == 0)
 338                        continue;
 339
 340                /* Set default current */
 341                lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
 342                        pdata->led_config[i].led_current);
 343
 344                lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0xff);
 345                /* let current stabilize 2 - 4ms before measurements start */
 346                usleep_range(2000, 4000);
 347                lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL,
 348                             LP5523_EN_LEDTEST | i);
 349                /* ADC conversion time is 2.7 ms typically */
 350                usleep_range(3000, 6000);
 351                ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
 352                if (ret < 0)
 353                        goto fail;
 354
 355                if (!(status & LP5523_LEDTEST_DONE))
 356                        usleep_range(3000, 6000);/* Was not ready. Wait. */
 357
 358                ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &adc);
 359                if (ret < 0)
 360                        goto fail;
 361
 362                if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
 363                        pos += sprintf(buf + pos, "LED %d FAIL\n", i);
 364
 365                lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0x00);
 366
 367                /* Restore current */
 368                lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
 369                        led->led_current);
 370                led++;
 371        }
 372        if (pos == 0)
 373                pos = sprintf(buf, "OK\n");
 374        goto release_lock;
 375fail:
 376        pos = sprintf(buf, "FAIL\n");
 377
 378release_lock:
 379        mutex_unlock(&chip->lock);
 380
 381        return pos;
 382}
 383
 384static void lp5523_led_brightness_work(struct work_struct *work)
 385{
 386        struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 387                                              brightness_work);
 388        struct lp55xx_chip *chip = led->chip;
 389
 390        mutex_lock(&chip->lock);
 391        lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + led->chan_nr,
 392                     led->brightness);
 393        mutex_unlock(&chip->lock);
 394}
 395
 396static DEVICE_ATTR(selftest, S_IRUGO, lp5523_selftest, NULL);
 397
 398static struct attribute *lp5523_attributes[] = {
 399        &dev_attr_selftest.attr,
 400        NULL,
 401};
 402
 403static const struct attribute_group lp5523_group = {
 404        .attrs = lp5523_attributes,
 405};
 406
 407/* Chip specific configurations */
 408static struct lp55xx_device_config lp5523_cfg = {
 409        .reset = {
 410                .addr = LP5523_REG_RESET,
 411                .val  = LP5523_RESET,
 412        },
 413        .enable = {
 414                .addr = LP5523_REG_ENABLE,
 415                .val  = LP5523_ENABLE,
 416        },
 417        .max_channel  = LP5523_MAX_LEDS,
 418        .post_init_device   = lp5523_post_init_device,
 419        .brightness_work_fn = lp5523_led_brightness_work,
 420        .set_led_current    = lp5523_set_led_current,
 421        .firmware_cb        = lp5523_firmware_loaded,
 422        .run_engine         = lp5523_run_engine,
 423        .dev_attr_group     = &lp5523_group,
 424};
 425
 426static int lp5523_probe(struct i2c_client *client,
 427                        const struct i2c_device_id *id)
 428{
 429        int ret;
 430        struct lp55xx_chip *chip;
 431        struct lp55xx_led *led;
 432        struct lp55xx_platform_data *pdata;
 433        struct device_node *np = client->dev.of_node;
 434
 435        if (!client->dev.platform_data) {
 436                if (np) {
 437                        ret = lp55xx_of_populate_pdata(&client->dev, np);
 438                        if (ret < 0)
 439                                return ret;
 440                } else {
 441                        dev_err(&client->dev, "no platform data\n");
 442                        return -EINVAL;
 443                }
 444        }
 445        pdata = client->dev.platform_data;
 446
 447        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 448        if (!chip)
 449                return -ENOMEM;
 450
 451        led = devm_kzalloc(&client->dev,
 452                        sizeof(*led) * pdata->num_channels, GFP_KERNEL);
 453        if (!led)
 454                return -ENOMEM;
 455
 456        chip->cl = client;
 457        chip->pdata = pdata;
 458        chip->cfg = &lp5523_cfg;
 459
 460        mutex_init(&chip->lock);
 461
 462        i2c_set_clientdata(client, led);
 463
 464        ret = lp55xx_init_device(chip);
 465        if (ret)
 466                goto err_init;
 467
 468        dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
 469
 470        ret = lp55xx_register_leds(led, chip);
 471        if (ret)
 472                goto err_register_leds;
 473
 474        ret = lp55xx_register_sysfs(chip);
 475        if (ret) {
 476                dev_err(&client->dev, "registering sysfs failed\n");
 477                goto err_register_sysfs;
 478        }
 479
 480        return 0;
 481
 482err_register_sysfs:
 483        lp55xx_unregister_leds(led, chip);
 484err_register_leds:
 485        lp55xx_deinit_device(chip);
 486err_init:
 487        return ret;
 488}
 489
 490static int lp5523_remove(struct i2c_client *client)
 491{
 492        struct lp55xx_led *led = i2c_get_clientdata(client);
 493        struct lp55xx_chip *chip = led->chip;
 494
 495        lp5523_stop_engine(chip);
 496        lp55xx_unregister_sysfs(chip);
 497        lp55xx_unregister_leds(led, chip);
 498        lp55xx_deinit_device(chip);
 499
 500        return 0;
 501}
 502
 503static const struct i2c_device_id lp5523_id[] = {
 504        { "lp5523",  LP5523 },
 505        { "lp55231", LP55231 },
 506        { }
 507};
 508
 509MODULE_DEVICE_TABLE(i2c, lp5523_id);
 510
 511#ifdef CONFIG_OF
 512static const struct of_device_id of_lp5523_leds_match[] = {
 513        { .compatible = "national,lp5523", },
 514        {},
 515};
 516
 517MODULE_DEVICE_TABLE(of, of_lp5523_leds_match);
 518#endif
 519
 520static struct i2c_driver lp5523_driver = {
 521        .driver = {
 522                .name   = "lp5523x",
 523                .of_match_table = of_match_ptr(of_lp5523_leds_match),
 524        },
 525        .probe          = lp5523_probe,
 526        .remove         = lp5523_remove,
 527        .id_table       = lp5523_id,
 528};
 529
 530module_i2c_driver(lp5523_driver);
 531
 532MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
 533MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 534MODULE_DESCRIPTION("LP5523 LED engine");
 535MODULE_LICENSE("GPL");
 536
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