drivers/leds/leds-lp5521.c

   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
 103 static 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
 109 static 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
 115 static 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
 122 static 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
 142 static 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
 148 static 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
 198 static 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
 246 err:
 247         dev_err(&chip->cl->dev, "wrong pattern format\n");
 248         return -EINVAL;
 249 }
 250
 251 static 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
 271 static 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
 320 static 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
 340 static 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
 352 static 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 */
 367 static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
 368
 369 static struct attribute *lp5521_attributes[] = {
 370         &dev_attr_selftest.attr,
 371         NULL
 372 };
 373
 374 static const struct attribute_group lp5521_group = {
 375         .attrs = lp5521_attributes,
 376 };
 377
 378 /* Chip specific configurations */
 379 static 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
 397 static 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
 445 err_register_sysfs:
 446         lp55xx_unregister_leds(led, chip);
 447 err_register_leds:
 448         lp55xx_deinit_device(chip);
 449 err_init:
 450         return ret;
 451 }
 452
 453 static 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
 466 static const struct i2c_device_id lp5521_id[] = {
 467         { "lp5521", 0 }, /* Three channel chip */
 468         { }
 469 };
 470 MODULE_DEVICE_TABLE(i2c, lp5521_id);
 471
 472 static 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
 481 module_i2c_driver(lp5521_driver);
 482
 483 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
 484 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 485 MODULE_DESCRIPTION("LP5521 LED engine");
 486 MODULE_LICENSE("GPL v2");