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 program_size; 224 int nrchars; 225 int offset = 0; 226 int ret; 227 int i; 228 229 /* clear program memory before updating */ 230 for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) 231 lp55xx_write(chip, addr[idx] + i, 0); 232 233 i = 0; 234 while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) { 235 /* separate sscanfs because length is working only for %s */ 236 ret = sscanf(data + offset, "%2s%n ", c, &nrchars); 237 if (ret != 1) 238 goto err; 239 240 ret = sscanf(c, "%2x", &cmd); 241 if (ret != 1) 242 goto err; 243 244 pattern[i] = (u8)cmd; 245 offset += nrchars; 246 i++; 247 } 248 249 /* Each instruction is 16bit long. Check that length is even */ 250 if (i % 2) 251 goto err; 252 253 program_size = i; 254 for (i = 0; i < program_size; i++) 255 lp55xx_write(chip, addr[idx] + i, pattern[i]); 256 257 return 0; 258 259 err: 260 dev_err(&chip->cl->dev, "wrong pattern format\n"); 261 return -EINVAL; 262 } 263 264 static void lp5521_firmware_loaded(struct lp55xx_chip *chip) 265 { 266 const struct firmware *fw = chip->fw; 267 268 if (fw->size > LP5521_PROGRAM_LENGTH) { 269 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", 270 fw->size); 271 return; 272 } 273 274 /* 275 * Program momery sequence 276 * 1) set engine mode to "LOAD" 277 * 2) write firmware data into program memory 278 */ 279 280 lp5521_load_engine(chip); 281 lp5521_update_program_memory(chip, fw->data, fw->size); 282 } 283 284 static int lp5521_post_init_device(struct lp55xx_chip *chip) 285 { 286 int ret; 287 u8 val; 288 289 /* 290 * Make sure that the chip is reset by reading back the r channel 291 * current reg. This is dummy read is required on some platforms - 292 * otherwise further access to the R G B channels in the 293 * LP5521_REG_ENABLE register will not have any effect - strange! 294 */ 295 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val); 296 if (ret) { 297 dev_err(&chip->cl->dev, "error in resetting chip\n"); 298 return ret; 299 } 300 if (val != LP5521_REG_R_CURR_DEFAULT) { 301 dev_err(&chip->cl->dev, 302 "unexpected data in register (expected 0x%x got 0x%x)\n", 303 LP5521_REG_R_CURR_DEFAULT, val); 304 ret = -EINVAL; 305 return ret; 306 } 307 usleep_range(10000, 20000); 308 309 /* Set all PWMs to direct control mode */ 310 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); 311 312 /* Update configuration for the clock setting */ 313 val = LP5521_DEFAULT_CFG; 314 if (!lp55xx_is_extclk_used(chip)) 315 val |= LP5521_CLK_INT; 316 317 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val); 318 if (ret) 319 return ret; 320 321 /* Initialize all channels PWM to zero -> leds off */ 322 lp55xx_write(chip, LP5521_REG_R_PWM, 0); 323 lp55xx_write(chip, LP5521_REG_G_PWM, 0); 324 lp55xx_write(chip, LP5521_REG_B_PWM, 0); 325 326 /* Set engines are set to run state when OP_MODE enables engines */ 327 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM); 328 if (ret) 329 return ret; 330 331 lp5521_wait_enable_done(); 332 333 return 0; 334 } 335 336 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf) 337 { 338 struct lp55xx_platform_data *pdata = chip->pdata; 339 int ret; 340 u8 status; 341 342 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status); 343 if (ret < 0) 344 return ret; 345 346 if (pdata->clock_mode != LP55XX_CLOCK_EXT) 347 return 0; 348 349 /* Check that ext clock is really in use if requested */ 350 if ((status & LP5521_EXT_CLK_USED) == 0) 351 return -EIO; 352 353 return 0; 354 } 355 356 static void lp5521_led_brightness_work(struct work_struct *work) 357 { 358 struct lp55xx_led *led = container_of(work, struct lp55xx_led, 359 brightness_work); 360 struct lp55xx_chip *chip = led->chip; 361 362 mutex_lock(&chip->lock); 363 lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr, 364 led->brightness); 365 mutex_unlock(&chip->lock); 366 } 367 368 static ssize_t lp5521_selftest(struct device *dev, 369 struct device_attribute *attr, 370 char *buf) 371 { 372 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 373 struct lp55xx_chip *chip = led->chip; 374 int ret; 375 376 mutex_lock(&chip->lock); 377 ret = lp5521_run_selftest(chip, buf); 378 mutex_unlock(&chip->lock); 379 380 return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK"); 381 } 382 383 /* device attributes */ 384 static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL); 385 386 static struct attribute *lp5521_attributes[] = { 387 &dev_attr_selftest.attr, 388 NULL 389 }; 390 391 static const struct attribute_group lp5521_group = { 392 .attrs = lp5521_attributes, 393 }; 394 395 /* Chip specific configurations */ 396 static struct lp55xx_device_config lp5521_cfg = { 397 .reset = { 398 .addr = LP5521_REG_RESET, 399 .val = LP5521_RESET, 400 }, 401 .enable = { 402 .addr = LP5521_REG_ENABLE, 403 .val = LP5521_ENABLE_DEFAULT, 404 }, 405 .max_channel = LP5521_MAX_LEDS, 406 .post_init_device = lp5521_post_init_device, 407 .brightness_work_fn = lp5521_led_brightness_work, 408 .set_led_current = lp5521_set_led_current, 409 .firmware_cb = lp5521_firmware_loaded, 410 .run_engine = lp5521_run_engine, 411 .dev_attr_group = &lp5521_group, 412 }; 413 414 static int lp5521_probe(struct i2c_client *client, 415 const struct i2c_device_id *id) 416 { 417 int ret; 418 struct lp55xx_chip *chip; 419 struct lp55xx_led *led; 420 struct lp55xx_platform_data *pdata; 421 struct device_node *np = client->dev.of_node; 422 423 if (!client->dev.platform_data) { 424 if (np) { 425 ret = lp55xx_of_populate_pdata(&client->dev, np); 426 if (ret < 0) 427 return ret; 428 } else { 429 dev_err(&client->dev, "no platform data\n"); 430 return -EINVAL; 431 } 432 } 433 pdata = client->dev.platform_data; 434 435 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 436 if (!chip) 437 return -ENOMEM; 438 439 led = devm_kzalloc(&client->dev, 440 sizeof(*led) * pdata->num_channels, GFP_KERNEL); 441 if (!led) 442 return -ENOMEM; 443 444 chip->cl = client; 445 chip->pdata = pdata; 446 chip->cfg = &lp5521_cfg; 447 448 mutex_init(&chip->lock); 449 450 i2c_set_clientdata(client, led); 451 452 ret = lp55xx_init_device(chip); 453 if (ret) 454 goto err_init; 455 456 dev_info(&client->dev, "%s programmable led chip found\n", id->name); 457 458 ret = lp55xx_register_leds(led, chip); 459 if (ret) 460 goto err_register_leds; 461 462 ret = lp55xx_register_sysfs(chip); 463 if (ret) { 464 dev_err(&client->dev, "registering sysfs failed\n"); 465 goto err_register_sysfs; 466 } 467 468 return 0; 469 470 err_register_sysfs: 471 lp55xx_unregister_leds(led, chip); 472 err_register_leds: 473 lp55xx_deinit_device(chip); 474 err_init: 475 return ret; 476 } 477 478 static int lp5521_remove(struct i2c_client *client) 479 { 480 struct lp55xx_led *led = i2c_get_clientdata(client); 481 struct lp55xx_chip *chip = led->chip; 482 483 lp5521_stop_engine(chip); 484 lp55xx_unregister_sysfs(chip); 485 lp55xx_unregister_leds(led, chip); 486 lp55xx_deinit_device(chip); 487 488 return 0; 489 } 490 491 static const struct i2c_device_id lp5521_id[] = { 492 { "lp5521", 0 }, /* Three channel chip */ 493 { } 494 }; 495 MODULE_DEVICE_TABLE(i2c, lp5521_id); 496 497 #ifdef CONFIG_OF 498 static const struct of_device_id of_lp5521_leds_match[] = { 499 { .compatible = "national,lp5521", }, 500 {}, 501 }; 502 503 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match); 504 #endif 505 static struct i2c_driver lp5521_driver = { 506 .driver = { 507 .name = "lp5521", 508 .of_match_table = of_match_ptr(of_lp5521_leds_match), 509 }, 510 .probe = lp5521_probe, 511 .remove = lp5521_remove, 512 .id_table = lp5521_id, 513 }; 514 515 module_i2c_driver(lp5521_driver); 516 517 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo"); 518 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 519 MODULE_DESCRIPTION("LP5521 LED engine"); 520 MODULE_LICENSE("GPL v2"); 521