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 115 116 static 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 } 121 122 static inline void lp5521_wait_enable_done(void) 123 { 124 /* it takes more 488 us to update ENABLE register */ 125 usleep_range(500, 600); 126 } 127 128 static 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 } 134 135 static 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 } 154 155 static void lp5521_stop_engine(struct lp55xx_chip *chip) 156 { 157 lp55xx_write(chip, LP5521_REG_OP_MODE, 0); 158 lp5521_wait_opmode_done(); 159 } 160 161 static 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 } 210 211 static 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; 260 261 err: 262 dev_err(&chip->cl->dev, "wrong pattern format\n"); 263 return -EINVAL; 264 } 265 266 static 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 } 285 286 static 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 } 337 338 static 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 } 357 358 static 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 } 369 370 static 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 } 388 show_mode(1) 389 show_mode(2) 390 show_mode(3) 391 392 static 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 } 420 store_mode(1) 421 store_mode(2) 422 store_mode(3) 423 424 static 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 } 440 store_load(1) 441 store_load(2) 442 store_load(3) 443 444 static 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 */ 460 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode); 461 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode); 462 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode); 463 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load); 464 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load); 465 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load); 466 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest); 467 468 static 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 }; 478 479 static const struct attribute_group lp5521_group = { 480 .attrs = lp5521_attributes, 481 }; 482 483 /* Chip specific configurations */ 484 static 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 }; 501 502 static 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; 557 558 err_register_sysfs: 559 lp55xx_unregister_leds(led, chip); 560 err_register_leds: 561 lp55xx_deinit_device(chip); 562 err_init: 563 return ret; 564 } 565 566 static 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 } 578 579 static const struct i2c_device_id lp5521_id[] = { 580 { "lp5521", 0 }, /* Three channel chip */ 581 { } 582 }; 583 MODULE_DEVICE_TABLE(i2c, lp5521_id); 584 585 #ifdef CONFIG_OF 586 static const struct of_device_id of_lp5521_leds_match[] = { 587 { .compatible = "national,lp5521", }, 588 {}, 589 }; 590 591 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match); 592 #endif 593 static 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 }; 602 603 module_i2c_driver(lp5521_driver); 604 605 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo"); 606 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 607 MODULE_DESCRIPTION("LP5521 LED engine"); 608 MODULE_LICENSE("GPL v2"); 609