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