linux/drivers/leds/leds-lp5521.c
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   1/*
   2 * LP5521 LED chip 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#include <linux/of.h>
  35
  36#include "leds-lp55xx-common.h"
  37
  38#define LP5521_PROGRAM_LENGTH           32
  39#define LP5521_MAX_LEDS                 3
  40#define LP5521_CMD_DIRECT               0x3F
  41
  42/* Registers */
  43#define LP5521_REG_ENABLE               0x00
  44#define LP5521_REG_OP_MODE              0x01
  45#define LP5521_REG_R_PWM                0x02
  46#define LP5521_REG_G_PWM                0x03
  47#define LP5521_REG_B_PWM                0x04
  48#define LP5521_REG_R_CURRENT            0x05
  49#define LP5521_REG_G_CURRENT            0x06
  50#define LP5521_REG_B_CURRENT            0x07
  51#define LP5521_REG_CONFIG               0x08
  52#define LP5521_REG_STATUS               0x0C
  53#define LP5521_REG_RESET                0x0D
  54#define LP5521_REG_R_PROG_MEM           0x10
  55#define LP5521_REG_G_PROG_MEM           0x30
  56#define LP5521_REG_B_PROG_MEM           0x50
  57
  58/* Base register to set LED current */
  59#define LP5521_REG_LED_CURRENT_BASE     LP5521_REG_R_CURRENT
  60/* Base register to set the brightness */
  61#define LP5521_REG_LED_PWM_BASE         LP5521_REG_R_PWM
  62
  63/* Bits in ENABLE register */
  64#define LP5521_MASTER_ENABLE            0x40    /* Chip master enable */
  65#define LP5521_LOGARITHMIC_PWM          0x80    /* Logarithmic PWM adjustment */
  66#define LP5521_EXEC_RUN                 0x2A
  67#define LP5521_ENABLE_DEFAULT   \
  68        (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
  69#define LP5521_ENABLE_RUN_PROGRAM       \
  70        (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
  71
  72/* CONFIG register */
  73#define LP5521_PWM_HF                   0x40    /* PWM: 0 = 256Hz, 1 = 558Hz */
  74#define LP5521_PWRSAVE_EN               0x20    /* 1 = Power save mode */
  75#define LP5521_CP_MODE_OFF              0       /* Charge pump (CP) off */
  76#define LP5521_CP_MODE_BYPASS           8       /* CP forced to bypass mode */
  77#define LP5521_CP_MODE_1X5              0x10    /* CP forced to 1.5x mode */
  78#define LP5521_CP_MODE_AUTO             0x18    /* Automatic mode selection */
  79#define LP5521_R_TO_BATT                0x04    /* R out: 0 = CP, 1 = Vbat */
  80#define LP5521_CLK_INT                  0x01    /* Internal clock */
  81#define LP5521_DEFAULT_CFG              \
  82        (LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO)
  83
  84/* Status */
  85#define LP5521_EXT_CLK_USED             0x08
  86
  87/* default R channel current register value */
  88#define LP5521_REG_R_CURR_DEFAULT       0xAF
  89
  90/* Reset register value */
  91#define LP5521_RESET                    0xFF
  92
  93/* Program Memory Operations */
  94#define LP5521_MODE_R_M                 0x30    /* Operation Mode Register */
  95#define LP5521_MODE_G_M                 0x0C
  96#define LP5521_MODE_B_M                 0x03
  97#define LP5521_LOAD_R                   0x10
  98#define LP5521_LOAD_G                   0x04
  99#define LP5521_LOAD_B                   0x01
 100
 101#define LP5521_R_IS_LOADING(mode)       \
 102        ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
 103#define LP5521_G_IS_LOADING(mode)       \
 104        ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
 105#define LP5521_B_IS_LOADING(mode)       \
 106        ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
 107
 108#define LP5521_EXEC_R_M                 0x30    /* Enable Register */
 109#define LP5521_EXEC_G_M                 0x0C
 110#define LP5521_EXEC_B_M                 0x03
 111#define LP5521_EXEC_M                   0x3F
 112#define LP5521_RUN_R                    0x20
 113#define LP5521_RUN_G                    0x08
 114#define LP5521_RUN_B                    0x02
 115
 116static inline void lp5521_wait_opmode_done(void)
 117{
 118        /* operation mode change needs to be longer than 153 us */
 119        usleep_range(200, 300);
 120}
 121
 122static inline void lp5521_wait_enable_done(void)
 123{
 124        /* it takes more 488 us to update ENABLE register */
 125        usleep_range(500, 600);
 126}
 127
 128static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
 129{
 130        led->led_current = led_current;
 131        lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
 132                led_current);
 133}
 134
 135static void lp5521_load_engine(struct lp55xx_chip *chip)
 136{
 137        enum lp55xx_engine_index idx = chip->engine_idx;
 138        u8 mask[] = {
 139                [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
 140                [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
 141                [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
 142        };
 143
 144        u8 val[] = {
 145                [LP55XX_ENGINE_1] = LP5521_LOAD_R,
 146                [LP55XX_ENGINE_2] = LP5521_LOAD_G,
 147                [LP55XX_ENGINE_3] = LP5521_LOAD_B,
 148        };
 149
 150        lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
 151
 152        lp5521_wait_opmode_done();
 153}
 154
 155static void lp5521_stop_engine(struct lp55xx_chip *chip)
 156{
 157        lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
 158        lp5521_wait_opmode_done();
 159}
 160
 161static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
 162{
 163        int ret;
 164        u8 mode;
 165        u8 exec;
 166
 167        /* stop engine */
 168        if (!start) {
 169                lp5521_stop_engine(chip);
 170                lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 171                lp5521_wait_opmode_done();
 172                return;
 173        }
 174
 175        /*
 176         * To run the engine,
 177         * operation mode and enable register should updated at the same time
 178         */
 179
 180        ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
 181        if (ret)
 182                return;
 183
 184        ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
 185        if (ret)
 186                return;
 187
 188        /* change operation mode to RUN only when each engine is loading */
 189        if (LP5521_R_IS_LOADING(mode)) {
 190                mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
 191                exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
 192        }
 193
 194        if (LP5521_G_IS_LOADING(mode)) {
 195                mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
 196                exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
 197        }
 198
 199        if (LP5521_B_IS_LOADING(mode)) {
 200                mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
 201                exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
 202        }
 203
 204        lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
 205        lp5521_wait_opmode_done();
 206
 207        lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
 208        lp5521_wait_enable_done();
 209}
 210
 211static int lp5521_update_program_memory(struct lp55xx_chip *chip,
 212                                        const u8 *data, size_t size)
 213{
 214        enum lp55xx_engine_index idx = chip->engine_idx;
 215        u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
 216        u8 addr[] = {
 217                [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
 218                [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
 219                [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
 220        };
 221        unsigned cmd;
 222        char c[3];
 223        int nrchars;
 224        int ret;
 225        int offset = 0;
 226        int i = 0;
 227
 228        while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
 229                /* separate sscanfs because length is working only for %s */
 230                ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 231                if (ret != 1)
 232                        goto err;
 233
 234                ret = sscanf(c, "%2x", &cmd);
 235                if (ret != 1)
 236                        goto err;
 237
 238                pattern[i] = (u8)cmd;
 239                offset += nrchars;
 240                i++;
 241        }
 242
 243        /* Each instruction is 16bit long. Check that length is even */
 244        if (i % 2)
 245                goto err;
 246
 247        mutex_lock(&chip->lock);
 248
 249        for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
 250                ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
 251                if (ret) {
 252                        mutex_unlock(&chip->lock);
 253                        return -EINVAL;
 254                }
 255        }
 256
 257        mutex_unlock(&chip->lock);
 258
 259        return size;
 260
 261err:
 262        dev_err(&chip->cl->dev, "wrong pattern format\n");
 263        return -EINVAL;
 264}
 265
 266static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
 267{
 268        const struct firmware *fw = chip->fw;
 269
 270        if (fw->size > LP5521_PROGRAM_LENGTH) {
 271                dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 272                        fw->size);
 273                return;
 274        }
 275
 276        /*
 277         * Program momery sequence
 278         *  1) set engine mode to "LOAD"
 279         *  2) write firmware data into program memory
 280         */
 281
 282        lp5521_load_engine(chip);
 283        lp5521_update_program_memory(chip, fw->data, fw->size);
 284}
 285
 286static int lp5521_post_init_device(struct lp55xx_chip *chip)
 287{
 288        int ret;
 289        u8 val;
 290
 291        /*
 292         * Make sure that the chip is reset by reading back the r channel
 293         * current reg. This is dummy read is required on some platforms -
 294         * otherwise further access to the R G B channels in the
 295         * LP5521_REG_ENABLE register will not have any effect - strange!
 296         */
 297        ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
 298        if (ret) {
 299                dev_err(&chip->cl->dev, "error in resetting chip\n");
 300                return ret;
 301        }
 302        if (val != LP5521_REG_R_CURR_DEFAULT) {
 303                dev_err(&chip->cl->dev,
 304                        "unexpected data in register (expected 0x%x got 0x%x)\n",
 305                        LP5521_REG_R_CURR_DEFAULT, val);
 306                ret = -EINVAL;
 307                return ret;
 308        }
 309        usleep_range(10000, 20000);
 310
 311        /* Set all PWMs to direct control mode */
 312        ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 313
 314        /* Update configuration for the clock setting */
 315        val = LP5521_DEFAULT_CFG;
 316        if (!lp55xx_is_extclk_used(chip))
 317                val |= LP5521_CLK_INT;
 318
 319        ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
 320        if (ret)
 321                return ret;
 322
 323        /* Initialize all channels PWM to zero -> leds off */
 324        lp55xx_write(chip, LP5521_REG_R_PWM, 0);
 325        lp55xx_write(chip, LP5521_REG_G_PWM, 0);
 326        lp55xx_write(chip, LP5521_REG_B_PWM, 0);
 327
 328        /* Set engines are set to run state when OP_MODE enables engines */
 329        ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
 330        if (ret)
 331                return ret;
 332
 333        lp5521_wait_enable_done();
 334
 335        return 0;
 336}
 337
 338static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
 339{
 340        struct lp55xx_platform_data *pdata = chip->pdata;
 341        int ret;
 342        u8 status;
 343
 344        ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
 345        if (ret < 0)
 346                return ret;
 347
 348        if (pdata->clock_mode != LP55XX_CLOCK_EXT)
 349                return 0;
 350
 351        /* Check that ext clock is really in use if requested */
 352        if  ((status & LP5521_EXT_CLK_USED) == 0)
 353                return -EIO;
 354
 355        return 0;
 356}
 357
 358static void lp5521_led_brightness_work(struct work_struct *work)
 359{
 360        struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 361                                              brightness_work);
 362        struct lp55xx_chip *chip = led->chip;
 363
 364        mutex_lock(&chip->lock);
 365        lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
 366                led->brightness);
 367        mutex_unlock(&chip->lock);
 368}
 369
 370static ssize_t show_engine_mode(struct device *dev,
 371                                struct device_attribute *attr,
 372                                char *buf, int nr)
 373{
 374        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 375        struct lp55xx_chip *chip = led->chip;
 376        enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
 377
 378        switch (mode) {
 379        case LP55XX_ENGINE_RUN:
 380                return sprintf(buf, "run\n");
 381        case LP55XX_ENGINE_LOAD:
 382                return sprintf(buf, "load\n");
 383        case LP55XX_ENGINE_DISABLED:
 384        default:
 385                return sprintf(buf, "disabled\n");
 386        }
 387}
 388show_mode(1)
 389show_mode(2)
 390show_mode(3)
 391
 392static ssize_t store_engine_mode(struct device *dev,
 393                                 struct device_attribute *attr,
 394                                 const char *buf, size_t len, int nr)
 395{
 396        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 397        struct lp55xx_chip *chip = led->chip;
 398        struct lp55xx_engine *engine = &chip->engines[nr - 1];
 399
 400        mutex_lock(&chip->lock);
 401
 402        chip->engine_idx = nr;
 403
 404        if (!strncmp(buf, "run", 3)) {
 405                lp5521_run_engine(chip, true);
 406                engine->mode = LP55XX_ENGINE_RUN;
 407        } else if (!strncmp(buf, "load", 4)) {
 408                lp5521_stop_engine(chip);
 409                lp5521_load_engine(chip);
 410                engine->mode = LP55XX_ENGINE_LOAD;
 411        } else if (!strncmp(buf, "disabled", 8)) {
 412                lp5521_stop_engine(chip);
 413                engine->mode = LP55XX_ENGINE_DISABLED;
 414        }
 415
 416        mutex_unlock(&chip->lock);
 417
 418        return len;
 419}
 420store_mode(1)
 421store_mode(2)
 422store_mode(3)
 423
 424static ssize_t store_engine_load(struct device *dev,
 425                             struct device_attribute *attr,
 426                             const char *buf, size_t len, int nr)
 427{
 428        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 429        struct lp55xx_chip *chip = led->chip;
 430
 431        mutex_lock(&chip->lock);
 432
 433        chip->engine_idx = nr;
 434        lp5521_load_engine(chip);
 435
 436        mutex_unlock(&chip->lock);
 437
 438        return lp5521_update_program_memory(chip, buf, len);
 439}
 440store_load(1)
 441store_load(2)
 442store_load(3)
 443
 444static ssize_t lp5521_selftest(struct device *dev,
 445                               struct device_attribute *attr,
 446                               char *buf)
 447{
 448        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 449        struct lp55xx_chip *chip = led->chip;
 450        int ret;
 451
 452        mutex_lock(&chip->lock);
 453        ret = lp5521_run_selftest(chip, buf);
 454        mutex_unlock(&chip->lock);
 455
 456        return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
 457}
 458
 459/* device attributes */
 460static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
 461static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
 462static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
 463static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
 464static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
 465static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
 466static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
 467
 468static struct attribute *lp5521_attributes[] = {
 469        &dev_attr_engine1_mode.attr,
 470        &dev_attr_engine2_mode.attr,
 471        &dev_attr_engine3_mode.attr,
 472        &dev_attr_engine1_load.attr,
 473        &dev_attr_engine2_load.attr,
 474        &dev_attr_engine3_load.attr,
 475        &dev_attr_selftest.attr,
 476        NULL
 477};
 478
 479static const struct attribute_group lp5521_group = {
 480        .attrs = lp5521_attributes,
 481};
 482
 483/* Chip specific configurations */
 484static struct lp55xx_device_config lp5521_cfg = {
 485        .reset = {
 486                .addr = LP5521_REG_RESET,
 487                .val  = LP5521_RESET,
 488        },
 489        .enable = {
 490                .addr = LP5521_REG_ENABLE,
 491                .val  = LP5521_ENABLE_DEFAULT,
 492        },
 493        .max_channel  = LP5521_MAX_LEDS,
 494        .post_init_device   = lp5521_post_init_device,
 495        .brightness_work_fn = lp5521_led_brightness_work,
 496        .set_led_current    = lp5521_set_led_current,
 497        .firmware_cb        = lp5521_firmware_loaded,
 498        .run_engine         = lp5521_run_engine,
 499        .dev_attr_group     = &lp5521_group,
 500};
 501
 502static int lp5521_probe(struct i2c_client *client,
 503                        const struct i2c_device_id *id)
 504{
 505        int ret;
 506        struct lp55xx_chip *chip;
 507        struct lp55xx_led *led;
 508        struct lp55xx_platform_data *pdata;
 509        struct device_node *np = client->dev.of_node;
 510
 511        if (!dev_get_platdata(&client->dev)) {
 512                if (np) {
 513                        ret = lp55xx_of_populate_pdata(&client->dev, np);
 514                        if (ret < 0)
 515                                return ret;
 516                } else {
 517                        dev_err(&client->dev, "no platform data\n");
 518                        return -EINVAL;
 519                }
 520        }
 521        pdata = dev_get_platdata(&client->dev);
 522
 523        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 524        if (!chip)
 525                return -ENOMEM;
 526
 527        led = devm_kzalloc(&client->dev,
 528                        sizeof(*led) * pdata->num_channels, GFP_KERNEL);
 529        if (!led)
 530                return -ENOMEM;
 531
 532        chip->cl = client;
 533        chip->pdata = pdata;
 534        chip->cfg = &lp5521_cfg;
 535
 536        mutex_init(&chip->lock);
 537
 538        i2c_set_clientdata(client, led);
 539
 540        ret = lp55xx_init_device(chip);
 541        if (ret)
 542                goto err_init;
 543
 544        dev_info(&client->dev, "%s programmable led chip found\n", id->name);
 545
 546        ret = lp55xx_register_leds(led, chip);
 547        if (ret)
 548                goto err_register_leds;
 549
 550        ret = lp55xx_register_sysfs(chip);
 551        if (ret) {
 552                dev_err(&client->dev, "registering sysfs failed\n");
 553                goto err_register_sysfs;
 554        }
 555
 556        return 0;
 557
 558err_register_sysfs:
 559        lp55xx_unregister_leds(led, chip);
 560err_register_leds:
 561        lp55xx_deinit_device(chip);
 562err_init:
 563        return ret;
 564}
 565
 566static int lp5521_remove(struct i2c_client *client)
 567{
 568        struct lp55xx_led *led = i2c_get_clientdata(client);
 569        struct lp55xx_chip *chip = led->chip;
 570
 571        lp5521_stop_engine(chip);
 572        lp55xx_unregister_sysfs(chip);
 573        lp55xx_unregister_leds(led, chip);
 574        lp55xx_deinit_device(chip);
 575
 576        return 0;
 577}
 578
 579static const struct i2c_device_id lp5521_id[] = {
 580        { "lp5521", 0 }, /* Three channel chip */
 581        { }
 582};
 583MODULE_DEVICE_TABLE(i2c, lp5521_id);
 584
 585#ifdef CONFIG_OF
 586static const struct of_device_id of_lp5521_leds_match[] = {
 587        { .compatible = "national,lp5521", },
 588        {},
 589};
 590
 591MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
 592#endif
 593static struct i2c_driver lp5521_driver = {
 594        .driver = {
 595                .name   = "lp5521",
 596                .of_match_table = of_match_ptr(of_lp5521_leds_match),
 597        },
 598        .probe          = lp5521_probe,
 599        .remove         = lp5521_remove,
 600        .id_table       = lp5521_id,
 601};
 602
 603module_i2c_driver(lp5521_driver);
 604
 605MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
 606MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 607MODULE_DESCRIPTION("LP5521 LED engine");
 608MODULE_LICENSE("GPL v2");
 609
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