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_all_engines(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_stop_engine(struct lp55xx_chip *chip) 162 { 163 enum lp55xx_engine_index idx = chip->engine_idx; 164 u8 mask[] = { 165 [LP55XX_ENGINE_1] = LP5521_MODE_R_M, 166 [LP55XX_ENGINE_2] = LP5521_MODE_G_M, 167 [LP55XX_ENGINE_3] = LP5521_MODE_B_M, 168 }; 169 170 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], 0); 171 172 lp5521_wait_opmode_done(); 173 } 174 175 static void lp5521_run_engine(struct lp55xx_chip *chip, bool start) 176 { 177 int ret; 178 u8 mode; 179 u8 exec; 180 181 /* stop engine */ 182 if (!start) { 183 lp5521_stop_engine(chip); 184 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); 185 lp5521_wait_opmode_done(); 186 return; 187 } 188 189 /* 190 * To run the engine, 191 * operation mode and enable register should updated at the same time 192 */ 193 194 ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode); 195 if (ret) 196 return; 197 198 ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec); 199 if (ret) 200 return; 201 202 /* change operation mode to RUN only when each engine is loading */ 203 if (LP5521_R_IS_LOADING(mode)) { 204 mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R; 205 exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R; 206 } 207 208 if (LP5521_G_IS_LOADING(mode)) { 209 mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G; 210 exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G; 211 } 212 213 if (LP5521_B_IS_LOADING(mode)) { 214 mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B; 215 exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B; 216 } 217 218 lp55xx_write(chip, LP5521_REG_OP_MODE, mode); 219 lp5521_wait_opmode_done(); 220 221 lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec); 222 lp5521_wait_enable_done(); 223 } 224 225 static int lp5521_update_program_memory(struct lp55xx_chip *chip, 226 const u8 *data, size_t size) 227 { 228 enum lp55xx_engine_index idx = chip->engine_idx; 229 u8 pattern[LP5521_PROGRAM_LENGTH] = {0}; 230 u8 addr[] = { 231 [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM, 232 [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM, 233 [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM, 234 }; 235 unsigned cmd; 236 char c[3]; 237 int nrchars; 238 int ret; 239 int offset = 0; 240 int i = 0; 241 242 while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) { 243 /* separate sscanfs because length is working only for %s */ 244 ret = sscanf(data + offset, "%2s%n ", c, &nrchars); 245 if (ret != 1) 246 goto err; 247 248 ret = sscanf(c, "%2x", &cmd); 249 if (ret != 1) 250 goto err; 251 252 pattern[i] = (u8)cmd; 253 offset += nrchars; 254 i++; 255 } 256 257 /* Each instruction is 16bit long. Check that length is even */ 258 if (i % 2) 259 goto err; 260 261 for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) { 262 ret = lp55xx_write(chip, addr[idx] + i, pattern[i]); 263 if (ret) 264 return -EINVAL; 265 } 266 267 return size; 268 269 err: 270 dev_err(&chip->cl->dev, "wrong pattern format\n"); 271 return -EINVAL; 272 } 273 274 static void lp5521_firmware_loaded(struct lp55xx_chip *chip) 275 { 276 const struct firmware *fw = chip->fw; 277 278 if (fw->size > LP5521_PROGRAM_LENGTH) { 279 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", 280 fw->size); 281 return; 282 } 283 284 /* 285 * Program momery sequence 286 * 1) set engine mode to "LOAD" 287 * 2) write firmware data into program memory 288 */ 289 290 lp5521_load_engine(chip); 291 lp5521_update_program_memory(chip, fw->data, fw->size); 292 } 293 294 static int lp5521_post_init_device(struct lp55xx_chip *chip) 295 { 296 int ret; 297 u8 val; 298 299 /* 300 * Make sure that the chip is reset by reading back the r channel 301 * current reg. This is dummy read is required on some platforms - 302 * otherwise further access to the R G B channels in the 303 * LP5521_REG_ENABLE register will not have any effect - strange! 304 */ 305 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val); 306 if (ret) { 307 dev_err(&chip->cl->dev, "error in resetting chip\n"); 308 return ret; 309 } 310 if (val != LP5521_REG_R_CURR_DEFAULT) { 311 dev_err(&chip->cl->dev, 312 "unexpected data in register (expected 0x%x got 0x%x)\n", 313 LP5521_REG_R_CURR_DEFAULT, val); 314 ret = -EINVAL; 315 return ret; 316 } 317 usleep_range(10000, 20000); 318 319 /* Set all PWMs to direct control mode */ 320 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); 321 322 /* Update configuration for the clock setting */ 323 val = LP5521_DEFAULT_CFG; 324 if (!lp55xx_is_extclk_used(chip)) 325 val |= LP5521_CLK_INT; 326 327 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val); 328 if (ret) 329 return ret; 330 331 /* Initialize all channels PWM to zero -> leds off */ 332 lp55xx_write(chip, LP5521_REG_R_PWM, 0); 333 lp55xx_write(chip, LP5521_REG_G_PWM, 0); 334 lp55xx_write(chip, LP5521_REG_B_PWM, 0); 335 336 /* Set engines are set to run state when OP_MODE enables engines */ 337 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM); 338 if (ret) 339 return ret; 340 341 lp5521_wait_enable_done(); 342 343 return 0; 344 } 345 346 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf) 347 { 348 struct lp55xx_platform_data *pdata = chip->pdata; 349 int ret; 350 u8 status; 351 352 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status); 353 if (ret < 0) 354 return ret; 355 356 if (pdata->clock_mode != LP55XX_CLOCK_EXT) 357 return 0; 358 359 /* Check that ext clock is really in use if requested */ 360 if ((status & LP5521_EXT_CLK_USED) == 0) 361 return -EIO; 362 363 return 0; 364 } 365 366 static void lp5521_led_brightness_work(struct work_struct *work) 367 { 368 struct lp55xx_led *led = container_of(work, struct lp55xx_led, 369 brightness_work); 370 struct lp55xx_chip *chip = led->chip; 371 372 mutex_lock(&chip->lock); 373 lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr, 374 led->brightness); 375 mutex_unlock(&chip->lock); 376 } 377 378 static ssize_t show_engine_mode(struct device *dev, 379 struct device_attribute *attr, 380 char *buf, int nr) 381 { 382 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 383 struct lp55xx_chip *chip = led->chip; 384 enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode; 385 386 switch (mode) { 387 case LP55XX_ENGINE_RUN: 388 return sprintf(buf, "run\n"); 389 case LP55XX_ENGINE_LOAD: 390 return sprintf(buf, "load\n"); 391 case LP55XX_ENGINE_DISABLED: 392 default: 393 return sprintf(buf, "disabled\n"); 394 } 395 } 396 show_mode(1) 397 show_mode(2) 398 show_mode(3) 399 400 static ssize_t store_engine_mode(struct device *dev, 401 struct device_attribute *attr, 402 const char *buf, size_t len, int nr) 403 { 404 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 405 struct lp55xx_chip *chip = led->chip; 406 struct lp55xx_engine *engine = &chip->engines[nr - 1]; 407 408 mutex_lock(&chip->lock); 409 410 chip->engine_idx = nr; 411 412 if (!strncmp(buf, "run", 3)) { 413 lp5521_run_engine(chip, true); 414 engine->mode = LP55XX_ENGINE_RUN; 415 } else if (!strncmp(buf, "load", 4)) { 416 lp5521_stop_engine(chip); 417 lp5521_load_engine(chip); 418 engine->mode = LP55XX_ENGINE_LOAD; 419 } else if (!strncmp(buf, "disabled", 8)) { 420 lp5521_stop_engine(chip); 421 engine->mode = LP55XX_ENGINE_DISABLED; 422 } 423 424 mutex_unlock(&chip->lock); 425 426 return len; 427 } 428 store_mode(1) 429 store_mode(2) 430 store_mode(3) 431 432 static ssize_t store_engine_load(struct device *dev, 433 struct device_attribute *attr, 434 const char *buf, size_t len, int nr) 435 { 436 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 437 struct lp55xx_chip *chip = led->chip; 438 int ret; 439 440 mutex_lock(&chip->lock); 441 442 chip->engine_idx = nr; 443 lp5521_load_engine(chip); 444 ret = lp5521_update_program_memory(chip, buf, len); 445 446 mutex_unlock(&chip->lock); 447 448 return ret; 449 } 450 store_load(1) 451 store_load(2) 452 store_load(3) 453 454 static ssize_t lp5521_selftest(struct device *dev, 455 struct device_attribute *attr, 456 char *buf) 457 { 458 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 459 struct lp55xx_chip *chip = led->chip; 460 int ret; 461 462 mutex_lock(&chip->lock); 463 ret = lp5521_run_selftest(chip, buf); 464 mutex_unlock(&chip->lock); 465 466 return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK"); 467 } 468 469 /* device attributes */ 470 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode); 471 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode); 472 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode); 473 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load); 474 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load); 475 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load); 476 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest); 477 478 static struct attribute *lp5521_attributes[] = { 479 &dev_attr_engine1_mode.attr, 480 &dev_attr_engine2_mode.attr, 481 &dev_attr_engine3_mode.attr, 482 &dev_attr_engine1_load.attr, 483 &dev_attr_engine2_load.attr, 484 &dev_attr_engine3_load.attr, 485 &dev_attr_selftest.attr, 486 NULL 487 }; 488 489 static const struct attribute_group lp5521_group = { 490 .attrs = lp5521_attributes, 491 }; 492 493 /* Chip specific configurations */ 494 static struct lp55xx_device_config lp5521_cfg = { 495 .reset = { 496 .addr = LP5521_REG_RESET, 497 .val = LP5521_RESET, 498 }, 499 .enable = { 500 .addr = LP5521_REG_ENABLE, 501 .val = LP5521_ENABLE_DEFAULT, 502 }, 503 .max_channel = LP5521_MAX_LEDS, 504 .post_init_device = lp5521_post_init_device, 505 .brightness_work_fn = lp5521_led_brightness_work, 506 .set_led_current = lp5521_set_led_current, 507 .firmware_cb = lp5521_firmware_loaded, 508 .run_engine = lp5521_run_engine, 509 .dev_attr_group = &lp5521_group, 510 }; 511 512 static int lp5521_probe(struct i2c_client *client, 513 const struct i2c_device_id *id) 514 { 515 int ret; 516 struct lp55xx_chip *chip; 517 struct lp55xx_led *led; 518 struct lp55xx_platform_data *pdata; 519 struct device_node *np = client->dev.of_node; 520 521 if (!dev_get_platdata(&client->dev)) { 522 if (np) { 523 ret = lp55xx_of_populate_pdata(&client->dev, np); 524 if (ret < 0) 525 return ret; 526 } else { 527 dev_err(&client->dev, "no platform data\n"); 528 return -EINVAL; 529 } 530 } 531 pdata = dev_get_platdata(&client->dev); 532 533 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 534 if (!chip) 535 return -ENOMEM; 536 537 led = devm_kzalloc(&client->dev, 538 sizeof(*led) * pdata->num_channels, GFP_KERNEL); 539 if (!led) 540 return -ENOMEM; 541 542 chip->cl = client; 543 chip->pdata = pdata; 544 chip->cfg = &lp5521_cfg; 545 546 mutex_init(&chip->lock); 547 548 i2c_set_clientdata(client, led); 549 550 ret = lp55xx_init_device(chip); 551 if (ret) 552 goto err_init; 553 554 dev_info(&client->dev, "%s programmable led chip found\n", id->name); 555 556 ret = lp55xx_register_leds(led, chip); 557 if (ret) 558 goto err_register_leds; 559 560 ret = lp55xx_register_sysfs(chip); 561 if (ret) { 562 dev_err(&client->dev, "registering sysfs failed\n"); 563 goto err_register_sysfs; 564 } 565 566 return 0; 567 568 err_register_sysfs: 569 lp55xx_unregister_leds(led, chip); 570 err_register_leds: 571 lp55xx_deinit_device(chip); 572 err_init: 573 return ret; 574 } 575 576 static int lp5521_remove(struct i2c_client *client) 577 { 578 struct lp55xx_led *led = i2c_get_clientdata(client); 579 struct lp55xx_chip *chip = led->chip; 580 581 lp5521_stop_all_engines(chip); 582 lp55xx_unregister_sysfs(chip); 583 lp55xx_unregister_leds(led, chip); 584 lp55xx_deinit_device(chip); 585 586 return 0; 587 } 588 589 static const struct i2c_device_id lp5521_id[] = { 590 { "lp5521", 0 }, /* Three channel chip */ 591 { } 592 }; 593 MODULE_DEVICE_TABLE(i2c, lp5521_id); 594 595 #ifdef CONFIG_OF 596 static const struct of_device_id of_lp5521_leds_match[] = { 597 { .compatible = "national,lp5521", }, 598 {}, 599 }; 600 601 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match); 602 #endif 603 static struct i2c_driver lp5521_driver = { 604 .driver = { 605 .name = "lp5521", 606 .of_match_table = of_match_ptr(of_lp5521_leds_match), 607 }, 608 .probe = lp5521_probe, 609 .remove = lp5521_remove, 610 .id_table = lp5521_id, 611 }; 612 613 module_i2c_driver(lp5521_driver); 614 615 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo"); 616 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 617 MODULE_DESCRIPTION("LP5521 LED engine"); 618 MODULE_LICENSE("GPL v2"); 619