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 program_size;
 224        int nrchars;
 225        int offset = 0;
 226        int ret;
 227        int i;
 228
 229        /* clear program memory before updating */
 230        for (i = 0; i < LP5521_PROGRAM_LENGTH; i++)
 231                lp55xx_write(chip, addr[idx] + i, 0);
 232
 233        i = 0;
 234        while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
 235                /* separate sscanfs because length is working only for %s */
 236                ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 237                if (ret != 1)
 238                        goto err;
 239
 240                ret = sscanf(c, "%2x", &cmd);
 241                if (ret != 1)
 242                        goto err;
 243
 244                pattern[i] = (u8)cmd;
 245                offset += nrchars;
 246                i++;
 247        }
 248
 249        /* Each instruction is 16bit long. Check that length is even */
 250        if (i % 2)
 251                goto err;
 252
 253        program_size = i;
 254        for (i = 0; i < program_size; i++)
 255                lp55xx_write(chip, addr[idx] + i, pattern[i]);
 256
 257        return 0;
 258
 259err:
 260        dev_err(&chip->cl->dev, "wrong pattern format\n");
 261        return -EINVAL;
 262}
 263
 264static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
 265{
 266        const struct firmware *fw = chip->fw;
 267
 268        if (fw->size > LP5521_PROGRAM_LENGTH) {
 269                dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 270                        fw->size);
 271                return;
 272        }
 273
 274        /*
 275         * Program momery sequence
 276         *  1) set engine mode to "LOAD"
 277         *  2) write firmware data into program memory
 278         */
 279
 280        lp5521_load_engine(chip);
 281        lp5521_update_program_memory(chip, fw->data, fw->size);
 282}
 283
 284static int lp5521_post_init_device(struct lp55xx_chip *chip)
 285{
 286        int ret;
 287        u8 val;
 288
 289        /*
 290         * Make sure that the chip is reset by reading back the r channel
 291         * current reg. This is dummy read is required on some platforms -
 292         * otherwise further access to the R G B channels in the
 293         * LP5521_REG_ENABLE register will not have any effect - strange!
 294         */
 295        ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
 296        if (ret) {
 297                dev_err(&chip->cl->dev, "error in resetting chip\n");
 298                return ret;
 299        }
 300        if (val != LP5521_REG_R_CURR_DEFAULT) {
 301                dev_err(&chip->cl->dev,
 302                        "unexpected data in register (expected 0x%x got 0x%x)\n",
 303                        LP5521_REG_R_CURR_DEFAULT, val);
 304                ret = -EINVAL;
 305                return ret;
 306        }
 307        usleep_range(10000, 20000);
 308
 309        /* Set all PWMs to direct control mode */
 310        ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 311
 312        /* Update configuration for the clock setting */
 313        val = LP5521_DEFAULT_CFG;
 314        if (!lp55xx_is_extclk_used(chip))
 315                val |= LP5521_CLK_INT;
 316
 317        ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
 318        if (ret)
 319                return ret;
 320
 321        /* Initialize all channels PWM to zero -> leds off */
 322        lp55xx_write(chip, LP5521_REG_R_PWM, 0);
 323        lp55xx_write(chip, LP5521_REG_G_PWM, 0);
 324        lp55xx_write(chip, LP5521_REG_B_PWM, 0);
 325
 326        /* Set engines are set to run state when OP_MODE enables engines */
 327        ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
 328        if (ret)
 329                return ret;
 330
 331        lp5521_wait_enable_done();
 332
 333        return 0;
 334}
 335
 336static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
 337{
 338        struct lp55xx_platform_data *pdata = chip->pdata;
 339        int ret;
 340        u8 status;
 341
 342        ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
 343        if (ret < 0)
 344                return ret;
 345
 346        if (pdata->clock_mode != LP55XX_CLOCK_EXT)
 347                return 0;
 348
 349        /* Check that ext clock is really in use if requested */
 350        if  ((status & LP5521_EXT_CLK_USED) == 0)
 351                return -EIO;
 352
 353        return 0;
 354}
 355
 356static void lp5521_led_brightness_work(struct work_struct *work)
 357{
 358        struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 359                                              brightness_work);
 360        struct lp55xx_chip *chip = led->chip;
 361
 362        mutex_lock(&chip->lock);
 363        lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
 364                led->brightness);
 365        mutex_unlock(&chip->lock);
 366}
 367
 368static ssize_t lp5521_selftest(struct device *dev,
 369                               struct device_attribute *attr,
 370                               char *buf)
 371{
 372        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 373        struct lp55xx_chip *chip = led->chip;
 374        int ret;
 375
 376        mutex_lock(&chip->lock);
 377        ret = lp5521_run_selftest(chip, buf);
 378        mutex_unlock(&chip->lock);
 379
 380        return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
 381}
 382
 383/* device attributes */
 384static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
 385
 386static struct attribute *lp5521_attributes[] = {
 387        &dev_attr_selftest.attr,
 388        NULL
 389};
 390
 391static const struct attribute_group lp5521_group = {
 392        .attrs = lp5521_attributes,
 393};
 394
 395/* Chip specific configurations */
 396static struct lp55xx_device_config lp5521_cfg = {
 397        .reset = {
 398                .addr = LP5521_REG_RESET,
 399                .val  = LP5521_RESET,
 400        },
 401        .enable = {
 402                .addr = LP5521_REG_ENABLE,
 403                .val  = LP5521_ENABLE_DEFAULT,
 404        },
 405        .max_channel  = LP5521_MAX_LEDS,
 406        .post_init_device   = lp5521_post_init_device,
 407        .brightness_work_fn = lp5521_led_brightness_work,
 408        .set_led_current    = lp5521_set_led_current,
 409        .firmware_cb        = lp5521_firmware_loaded,
 410        .run_engine         = lp5521_run_engine,
 411        .dev_attr_group     = &lp5521_group,
 412};
 413
 414static int lp5521_probe(struct i2c_client *client,
 415                        const struct i2c_device_id *id)
 416{
 417        int ret;
 418        struct lp55xx_chip *chip;
 419        struct lp55xx_led *led;
 420        struct lp55xx_platform_data *pdata;
 421        struct device_node *np = client->dev.of_node;
 422
 423        if (!client->dev.platform_data) {
 424                if (np) {
 425                        ret = lp55xx_of_populate_pdata(&client->dev, np);
 426                        if (ret < 0)
 427                                return ret;
 428                } else {
 429                        dev_err(&client->dev, "no platform data\n");
 430                        return -EINVAL;
 431                }
 432        }
 433        pdata = client->dev.platform_data;
 434
 435        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 436        if (!chip)
 437                return -ENOMEM;
 438
 439        led = devm_kzalloc(&client->dev,
 440                        sizeof(*led) * pdata->num_channels, GFP_KERNEL);
 441        if (!led)
 442                return -ENOMEM;
 443
 444        chip->cl = client;
 445        chip->pdata = pdata;
 446        chip->cfg = &lp5521_cfg;
 447
 448        mutex_init(&chip->lock);
 449
 450        i2c_set_clientdata(client, led);
 451
 452        ret = lp55xx_init_device(chip);
 453        if (ret)
 454                goto err_init;
 455
 456        dev_info(&client->dev, "%s programmable led chip found\n", id->name);
 457
 458        ret = lp55xx_register_leds(led, chip);
 459        if (ret)
 460                goto err_register_leds;
 461
 462        ret = lp55xx_register_sysfs(chip);
 463        if (ret) {
 464                dev_err(&client->dev, "registering sysfs failed\n");
 465                goto err_register_sysfs;
 466        }
 467
 468        return 0;
 469
 470err_register_sysfs:
 471        lp55xx_unregister_leds(led, chip);
 472err_register_leds:
 473        lp55xx_deinit_device(chip);
 474err_init:
 475        return ret;
 476}
 477
 478static int lp5521_remove(struct i2c_client *client)
 479{
 480        struct lp55xx_led *led = i2c_get_clientdata(client);
 481        struct lp55xx_chip *chip = led->chip;
 482
 483        lp5521_stop_engine(chip);
 484        lp55xx_unregister_sysfs(chip);
 485        lp55xx_unregister_leds(led, chip);
 486        lp55xx_deinit_device(chip);
 487
 488        return 0;
 489}
 490
 491static const struct i2c_device_id lp5521_id[] = {
 492        { "lp5521", 0 }, /* Three channel chip */
 493        { }
 494};
 495MODULE_DEVICE_TABLE(i2c, lp5521_id);
 496
 497#ifdef CONFIG_OF
 498static const struct of_device_id of_lp5521_leds_match[] = {
 499        { .compatible = "national,lp5521", },
 500        {},
 501};
 502
 503MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
 504#endif
 505static struct i2c_driver lp5521_driver = {
 506        .driver = {
 507                .name   = "lp5521",
 508                .of_match_table = of_match_ptr(of_lp5521_leds_match),
 509        },
 510        .probe          = lp5521_probe,
 511        .remove         = lp5521_remove,
 512        .id_table       = lp5521_id,
 513};
 514
 515module_i2c_driver(lp5521_driver);
 516
 517MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
 518MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 519MODULE_DESCRIPTION("LP5521 LED engine");
 520MODULE_LICENSE("GPL v2");
 521
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