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
  35#include "leds-lp55xx-common.h"
  36
  37#define LP5521_PROGRAM_LENGTH           32
  38#define LP5521_MAX_LEDS                 3
  39#define LP5521_CMD_DIRECT               0x3F
  40
  41/* Registers */
  42#define LP5521_REG_ENABLE               0x00
  43#define LP5521_REG_OP_MODE              0x01
  44#define LP5521_REG_R_PWM                0x02
  45#define LP5521_REG_G_PWM                0x03
  46#define LP5521_REG_B_PWM                0x04
  47#define LP5521_REG_R_CURRENT            0x05
  48#define LP5521_REG_G_CURRENT            0x06
  49#define LP5521_REG_B_CURRENT            0x07
  50#define LP5521_REG_CONFIG               0x08
  51#define LP5521_REG_STATUS               0x0C
  52#define LP5521_REG_RESET                0x0D
  53#define LP5521_REG_R_PROG_MEM           0x10
  54#define LP5521_REG_G_PROG_MEM           0x30
  55#define LP5521_REG_B_PROG_MEM           0x50
  56
  57/* Base register to set LED current */
  58#define LP5521_REG_LED_CURRENT_BASE     LP5521_REG_R_CURRENT
  59/* Base register to set the brightness */
  60#define LP5521_REG_LED_PWM_BASE         LP5521_REG_R_PWM
  61
  62/* Bits in ENABLE register */
  63#define LP5521_MASTER_ENABLE            0x40    /* Chip master enable */
  64#define LP5521_LOGARITHMIC_PWM          0x80    /* Logarithmic PWM adjustment */
  65#define LP5521_EXEC_RUN                 0x2A
  66#define LP5521_ENABLE_DEFAULT   \
  67        (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
  68#define LP5521_ENABLE_RUN_PROGRAM       \
  69        (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
  70
  71/* Status */
  72#define LP5521_EXT_CLK_USED             0x08
  73
  74/* default R channel current register value */
  75#define LP5521_REG_R_CURR_DEFAULT       0xAF
  76
  77/* Reset register value */
  78#define LP5521_RESET                    0xFF
  79
  80/* Program Memory Operations */
  81#define LP5521_MODE_R_M                 0x30    /* Operation Mode Register */
  82#define LP5521_MODE_G_M                 0x0C
  83#define LP5521_MODE_B_M                 0x03
  84#define LP5521_LOAD_R                   0x10
  85#define LP5521_LOAD_G                   0x04
  86#define LP5521_LOAD_B                   0x01
  87
  88#define LP5521_R_IS_LOADING(mode)       \
  89        ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
  90#define LP5521_G_IS_LOADING(mode)       \
  91        ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
  92#define LP5521_B_IS_LOADING(mode)       \
  93        ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
  94
  95#define LP5521_EXEC_R_M                 0x30    /* Enable Register */
  96#define LP5521_EXEC_G_M                 0x0C
  97#define LP5521_EXEC_B_M                 0x03
  98#define LP5521_EXEC_M                   0x3F
  99#define LP5521_RUN_R                    0x20
 100#define LP5521_RUN_G                    0x08
 101#define LP5521_RUN_B                    0x02
 102
 103static inline void lp5521_wait_opmode_done(void)
 104{
 105        /* operation mode change needs to be longer than 153 us */
 106        usleep_range(200, 300);
 107}
 108
 109static inline void lp5521_wait_enable_done(void)
 110{
 111        /* it takes more 488 us to update ENABLE register */
 112        usleep_range(500, 600);
 113}
 114
 115static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
 116{
 117        led->led_current = led_current;
 118        lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
 119                led_current);
 120}
 121
 122static void lp5521_load_engine(struct lp55xx_chip *chip)
 123{
 124        enum lp55xx_engine_index idx = chip->engine_idx;
 125        u8 mask[] = {
 126                [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
 127                [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
 128                [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
 129        };
 130
 131        u8 val[] = {
 132                [LP55XX_ENGINE_1] = LP5521_LOAD_R,
 133                [LP55XX_ENGINE_2] = LP5521_LOAD_G,
 134                [LP55XX_ENGINE_3] = LP5521_LOAD_B,
 135        };
 136
 137        lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
 138
 139        lp5521_wait_opmode_done();
 140}
 141
 142static void lp5521_stop_engine(struct lp55xx_chip *chip)
 143{
 144        lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
 145        lp5521_wait_opmode_done();
 146}
 147
 148static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
 149{
 150        int ret;
 151        u8 mode;
 152        u8 exec;
 153
 154        /* stop engine */
 155        if (!start) {
 156                lp5521_stop_engine(chip);
 157                lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 158                lp5521_wait_opmode_done();
 159                return;
 160        }
 161
 162        /*
 163         * To run the engine,
 164         * operation mode and enable register should updated at the same time
 165         */
 166
 167        ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
 168        if (ret)
 169                return;
 170
 171        ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
 172        if (ret)
 173                return;
 174
 175        /* change operation mode to RUN only when each engine is loading */
 176        if (LP5521_R_IS_LOADING(mode)) {
 177                mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
 178                exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
 179        }
 180
 181        if (LP5521_G_IS_LOADING(mode)) {
 182                mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
 183                exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
 184        }
 185
 186        if (LP5521_B_IS_LOADING(mode)) {
 187                mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
 188                exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
 189        }
 190
 191        lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
 192        lp5521_wait_opmode_done();
 193
 194        lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
 195        lp5521_wait_enable_done();
 196}
 197
 198static int lp5521_update_program_memory(struct lp55xx_chip *chip,
 199                                        const u8 *data, size_t size)
 200{
 201        enum lp55xx_engine_index idx = chip->engine_idx;
 202        u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
 203        u8 addr[] = {
 204                [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
 205                [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
 206                [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
 207        };
 208        unsigned cmd;
 209        char c[3];
 210        int program_size;
 211        int nrchars;
 212        int offset = 0;
 213        int ret;
 214        int i;
 215
 216        /* clear program memory before updating */
 217        for (i = 0; i < LP5521_PROGRAM_LENGTH; i++)
 218                lp55xx_write(chip, addr[idx] + i, 0);
 219
 220        i = 0;
 221        while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
 222                /* separate sscanfs because length is working only for %s */
 223                ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 224                if (ret != 1)
 225                        goto err;
 226
 227                ret = sscanf(c, "%2x", &cmd);
 228                if (ret != 1)
 229                        goto err;
 230
 231                pattern[i] = (u8)cmd;
 232                offset += nrchars;
 233                i++;
 234        }
 235
 236        /* Each instruction is 16bit long. Check that length is even */
 237        if (i % 2)
 238                goto err;
 239
 240        program_size = i;
 241        for (i = 0; i < program_size; i++)
 242                lp55xx_write(chip, addr[idx] + i, pattern[i]);
 243
 244        return 0;
 245
 246err:
 247        dev_err(&chip->cl->dev, "wrong pattern format\n");
 248        return -EINVAL;
 249}
 250
 251static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
 252{
 253        const struct firmware *fw = chip->fw;
 254
 255        if (fw->size > LP5521_PROGRAM_LENGTH) {
 256                dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 257                        fw->size);
 258                return;
 259        }
 260
 261        /*
 262         * Program momery sequence
 263         *  1) set engine mode to "LOAD"
 264         *  2) write firmware data into program memory
 265         */
 266
 267        lp5521_load_engine(chip);
 268        lp5521_update_program_memory(chip, fw->data, fw->size);
 269}
 270
 271static int lp5521_post_init_device(struct lp55xx_chip *chip)
 272{
 273        int ret;
 274        u8 val;
 275
 276        /*
 277         * Make sure that the chip is reset by reading back the r channel
 278         * current reg. This is dummy read is required on some platforms -
 279         * otherwise further access to the R G B channels in the
 280         * LP5521_REG_ENABLE register will not have any effect - strange!
 281         */
 282        ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
 283        if (ret) {
 284                dev_err(&chip->cl->dev, "error in resetting chip\n");
 285                return ret;
 286        }
 287        if (val != LP5521_REG_R_CURR_DEFAULT) {
 288                dev_err(&chip->cl->dev,
 289                        "unexpected data in register (expected 0x%x got 0x%x)\n",
 290                        LP5521_REG_R_CURR_DEFAULT, val);
 291                ret = -EINVAL;
 292                return ret;
 293        }
 294        usleep_range(10000, 20000);
 295
 296        /* Set all PWMs to direct control mode */
 297        ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 298
 299        val = chip->pdata->update_config ?
 300                : (LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT);
 301        ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
 302        if (ret)
 303                return ret;
 304
 305        /* Initialize all channels PWM to zero -> leds off */
 306        lp55xx_write(chip, LP5521_REG_R_PWM, 0);
 307        lp55xx_write(chip, LP5521_REG_G_PWM, 0);
 308        lp55xx_write(chip, LP5521_REG_B_PWM, 0);
 309
 310        /* Set engines are set to run state when OP_MODE enables engines */
 311        ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
 312        if (ret)
 313                return ret;
 314
 315        lp5521_wait_enable_done();
 316
 317        return 0;
 318}
 319
 320static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
 321{
 322        struct lp55xx_platform_data *pdata = chip->pdata;
 323        int ret;
 324        u8 status;
 325
 326        ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
 327        if (ret < 0)
 328                return ret;
 329
 330        if (pdata->clock_mode != LP55XX_CLOCK_EXT)
 331                return 0;
 332
 333        /* Check that ext clock is really in use if requested */
 334        if  ((status & LP5521_EXT_CLK_USED) == 0)
 335                return -EIO;
 336
 337        return 0;
 338}
 339
 340static void lp5521_led_brightness_work(struct work_struct *work)
 341{
 342        struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 343                                              brightness_work);
 344        struct lp55xx_chip *chip = led->chip;
 345
 346        mutex_lock(&chip->lock);
 347        lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
 348                led->brightness);
 349        mutex_unlock(&chip->lock);
 350}
 351
 352static ssize_t lp5521_selftest(struct device *dev,
 353                               struct device_attribute *attr,
 354                               char *buf)
 355{
 356        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 357        struct lp55xx_chip *chip = led->chip;
 358        int ret;
 359
 360        mutex_lock(&chip->lock);
 361        ret = lp5521_run_selftest(chip, buf);
 362        mutex_unlock(&chip->lock);
 363        return sprintf(buf, "%s\n", ret ? "FAIL" : "OK");
 364}
 365
 366/* device attributes */
 367static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
 368
 369static struct attribute *lp5521_attributes[] = {
 370        &dev_attr_selftest.attr,
 371        NULL
 372};
 373
 374static const struct attribute_group lp5521_group = {
 375        .attrs = lp5521_attributes,
 376};
 377
 378/* Chip specific configurations */
 379static struct lp55xx_device_config lp5521_cfg = {
 380        .reset = {
 381                .addr = LP5521_REG_RESET,
 382                .val  = LP5521_RESET,
 383        },
 384        .enable = {
 385                .addr = LP5521_REG_ENABLE,
 386                .val  = LP5521_ENABLE_DEFAULT,
 387        },
 388        .max_channel  = LP5521_MAX_LEDS,
 389        .post_init_device   = lp5521_post_init_device,
 390        .brightness_work_fn = lp5521_led_brightness_work,
 391        .set_led_current    = lp5521_set_led_current,
 392        .firmware_cb        = lp5521_firmware_loaded,
 393        .run_engine         = lp5521_run_engine,
 394        .dev_attr_group     = &lp5521_group,
 395};
 396
 397static int lp5521_probe(struct i2c_client *client,
 398                        const struct i2c_device_id *id)
 399{
 400        int ret;
 401        struct lp55xx_chip *chip;
 402        struct lp55xx_led *led;
 403        struct lp55xx_platform_data *pdata = client->dev.platform_data;
 404
 405        if (!pdata) {
 406                dev_err(&client->dev, "no platform data\n");
 407                return -EINVAL;
 408        }
 409
 410        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 411        if (!chip)
 412                return -ENOMEM;
 413
 414        led = devm_kzalloc(&client->dev,
 415                        sizeof(*led) * pdata->num_channels, GFP_KERNEL);
 416        if (!led)
 417                return -ENOMEM;
 418
 419        chip->cl = client;
 420        chip->pdata = pdata;
 421        chip->cfg = &lp5521_cfg;
 422
 423        mutex_init(&chip->lock);
 424
 425        i2c_set_clientdata(client, led);
 426
 427        ret = lp55xx_init_device(chip);
 428        if (ret)
 429                goto err_init;
 430
 431        dev_info(&client->dev, "%s programmable led chip found\n", id->name);
 432
 433        ret = lp55xx_register_leds(led, chip);
 434        if (ret)
 435                goto err_register_leds;
 436
 437        ret = lp55xx_register_sysfs(chip);
 438        if (ret) {
 439                dev_err(&client->dev, "registering sysfs failed\n");
 440                goto err_register_sysfs;
 441        }
 442
 443        return 0;
 444
 445err_register_sysfs:
 446        lp55xx_unregister_leds(led, chip);
 447err_register_leds:
 448        lp55xx_deinit_device(chip);
 449err_init:
 450        return ret;
 451}
 452
 453static int lp5521_remove(struct i2c_client *client)
 454{
 455        struct lp55xx_led *led = i2c_get_clientdata(client);
 456        struct lp55xx_chip *chip = led->chip;
 457
 458        lp5521_stop_engine(chip);
 459        lp55xx_unregister_sysfs(chip);
 460        lp55xx_unregister_leds(led, chip);
 461        lp55xx_deinit_device(chip);
 462
 463        return 0;
 464}
 465
 466static const struct i2c_device_id lp5521_id[] = {
 467        { "lp5521", 0 }, /* Three channel chip */
 468        { }
 469};
 470MODULE_DEVICE_TABLE(i2c, lp5521_id);
 471
 472static struct i2c_driver lp5521_driver = {
 473        .driver = {
 474                .name   = "lp5521",
 475        },
 476        .probe          = lp5521_probe,
 477        .remove         = lp5521_remove,
 478        .id_table       = lp5521_id,
 479};
 480
 481module_i2c_driver(lp5521_driver);
 482
 483MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
 484MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 485MODULE_DESCRIPTION("LP5521 LED engine");
 486MODULE_LICENSE("GPL v2");
 487
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