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 /* CONFIG register */ 72 #define LP5521_PWM_HF 0x40 /* PWM: 0 = 256Hz, 1 = 558Hz */ 73 #define LP5521_PWRSAVE_EN 0x20 /* 1 = Power save mode */ 74 #define LP5521_CP_MODE_OFF 0 /* Charge pump (CP) off */ 75 #define LP5521_CP_MODE_BYPASS 8 /* CP forced to bypass mode */ 76 #define LP5521_CP_MODE_1X5 0x10 /* CP forced to 1.5x mode */ 77 #define LP5521_CP_MODE_AUTO 0x18 /* Automatic mode selection */ 78 #define LP5521_R_TO_BATT 0x04 /* R out: 0 = CP, 1 = Vbat */ 79 #define LP5521_CLK_INT 0x01 /* Internal clock */ 80 #define LP5521_DEFAULT_CFG \ 81 (LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO) 82 83 /* Status */ 84 #define LP5521_EXT_CLK_USED 0x08 85 86 /* default R channel current register value */ 87 #define LP5521_REG_R_CURR_DEFAULT 0xAF 88 89 /* Reset register value */ 90 #define LP5521_RESET 0xFF 91 92 /* Program Memory Operations */ 93 #define LP5521_MODE_R_M 0x30 /* Operation Mode Register */ 94 #define LP5521_MODE_G_M 0x0C 95 #define LP5521_MODE_B_M 0x03 96 #define LP5521_LOAD_R 0x10 97 #define LP5521_LOAD_G 0x04 98 #define LP5521_LOAD_B 0x01 99 100 #define LP5521_R_IS_LOADING(mode) \ 101 ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R) 102 #define LP5521_G_IS_LOADING(mode) \ 103 ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G) 104 #define LP5521_B_IS_LOADING(mode) \ 105 ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B) 106 107 #define LP5521_EXEC_R_M 0x30 /* Enable Register */ 108 #define LP5521_EXEC_G_M 0x0C 109 #define LP5521_EXEC_B_M 0x03 110 #define LP5521_EXEC_M 0x3F 111 #define LP5521_RUN_R 0x20 112 #define LP5521_RUN_G 0x08 113 #define LP5521_RUN_B 0x02 114 115 static inline void lp5521_wait_opmode_done(void) 116 { 117 /* operation mode change needs to be longer than 153 us */ 118 usleep_range(200, 300); 119 } 120 121 static inline void lp5521_wait_enable_done(void) 122 { 123 /* it takes more 488 us to update ENABLE register */ 124 usleep_range(500, 600); 125 } 126 127 static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current) 128 { 129 led->led_current = led_current; 130 lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr, 131 led_current); 132 } 133 134 static void lp5521_load_engine(struct lp55xx_chip *chip) 135 { 136 enum lp55xx_engine_index idx = chip->engine_idx; 137 u8 mask[] = { 138 [LP55XX_ENGINE_1] = LP5521_MODE_R_M, 139 [LP55XX_ENGINE_2] = LP5521_MODE_G_M, 140 [LP55XX_ENGINE_3] = LP5521_MODE_B_M, 141 }; 142 143 u8 val[] = { 144 [LP55XX_ENGINE_1] = LP5521_LOAD_R, 145 [LP55XX_ENGINE_2] = LP5521_LOAD_G, 146 [LP55XX_ENGINE_3] = LP5521_LOAD_B, 147 }; 148 149 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]); 150 151 lp5521_wait_opmode_done(); 152 } 153 154 static void lp5521_stop_engine(struct lp55xx_chip *chip) 155 { 156 lp55xx_write(chip, LP5521_REG_OP_MODE, 0); 157 lp5521_wait_opmode_done(); 158 } 159 160 static void lp5521_run_engine(struct lp55xx_chip *chip, bool start) 161 { 162 int ret; 163 u8 mode; 164 u8 exec; 165 166 /* stop engine */ 167 if (!start) { 168 lp5521_stop_engine(chip); 169 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); 170 lp5521_wait_opmode_done(); 171 return; 172 } 173 174 /* 175 * To run the engine, 176 * operation mode and enable register should updated at the same time 177 */ 178 179 ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode); 180 if (ret) 181 return; 182 183 ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec); 184 if (ret) 185 return; 186 187 /* change operation mode to RUN only when each engine is loading */ 188 if (LP5521_R_IS_LOADING(mode)) { 189 mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R; 190 exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R; 191 } 192 193 if (LP5521_G_IS_LOADING(mode)) { 194 mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G; 195 exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G; 196 } 197 198 if (LP5521_B_IS_LOADING(mode)) { 199 mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B; 200 exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B; 201 } 202 203 lp55xx_write(chip, LP5521_REG_OP_MODE, mode); 204 lp5521_wait_opmode_done(); 205 206 lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec); 207 lp5521_wait_enable_done(); 208 } 209 210 static int lp5521_update_program_memory(struct lp55xx_chip *chip, 211 const u8 *data, size_t size) 212 { 213 enum lp55xx_engine_index idx = chip->engine_idx; 214 u8 pattern[LP5521_PROGRAM_LENGTH] = {0}; 215 u8 addr[] = { 216 [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM, 217 [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM, 218 [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM, 219 }; 220 unsigned cmd; 221 char c[3]; 222 int program_size; 223 int nrchars; 224 int offset = 0; 225 int ret; 226 int i; 227 228 /* clear program memory before updating */ 229 for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) 230 lp55xx_write(chip, addr[idx] + i, 0); 231 232 i = 0; 233 while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) { 234 /* separate sscanfs because length is working only for %s */ 235 ret = sscanf(data + offset, "%2s%n ", c, &nrchars); 236 if (ret != 1) 237 goto err; 238 239 ret = sscanf(c, "%2x", &cmd); 240 if (ret != 1) 241 goto err; 242 243 pattern[i] = (u8)cmd; 244 offset += nrchars; 245 i++; 246 } 247 248 /* Each instruction is 16bit long. Check that length is even */ 249 if (i % 2) 250 goto err; 251 252 program_size = i; 253 for (i = 0; i < program_size; i++) 254 lp55xx_write(chip, addr[idx] + i, pattern[i]); 255 256 return 0; 257 258 err: 259 dev_err(&chip->cl->dev, "wrong pattern format\n"); 260 return -EINVAL; 261 } 262 263 static void lp5521_firmware_loaded(struct lp55xx_chip *chip) 264 { 265 const struct firmware *fw = chip->fw; 266 267 if (fw->size > LP5521_PROGRAM_LENGTH) { 268 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", 269 fw->size); 270 return; 271 } 272 273 /* 274 * Program momery sequence 275 * 1) set engine mode to "LOAD" 276 * 2) write firmware data into program memory 277 */ 278 279 lp5521_load_engine(chip); 280 lp5521_update_program_memory(chip, fw->data, fw->size); 281 } 282 283 static int lp5521_post_init_device(struct lp55xx_chip *chip) 284 { 285 int ret; 286 u8 val; 287 288 /* 289 * Make sure that the chip is reset by reading back the r channel 290 * current reg. This is dummy read is required on some platforms - 291 * otherwise further access to the R G B channels in the 292 * LP5521_REG_ENABLE register will not have any effect - strange! 293 */ 294 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val); 295 if (ret) { 296 dev_err(&chip->cl->dev, "error in resetting chip\n"); 297 return ret; 298 } 299 if (val != LP5521_REG_R_CURR_DEFAULT) { 300 dev_err(&chip->cl->dev, 301 "unexpected data in register (expected 0x%x got 0x%x)\n", 302 LP5521_REG_R_CURR_DEFAULT, val); 303 ret = -EINVAL; 304 return ret; 305 } 306 usleep_range(10000, 20000); 307 308 /* Set all PWMs to direct control mode */ 309 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); 310 311 /* Update configuration for the clock setting */ 312 val = LP5521_DEFAULT_CFG; 313 if (!lp55xx_is_extclk_used(chip)) 314 val |= LP5521_CLK_INT; 315 316 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val); 317 if (ret) 318 return ret; 319 320 /* Initialize all channels PWM to zero -> leds off */ 321 lp55xx_write(chip, LP5521_REG_R_PWM, 0); 322 lp55xx_write(chip, LP5521_REG_G_PWM, 0); 323 lp55xx_write(chip, LP5521_REG_B_PWM, 0); 324 325 /* Set engines are set to run state when OP_MODE enables engines */ 326 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM); 327 if (ret) 328 return ret; 329 330 lp5521_wait_enable_done(); 331 332 return 0; 333 } 334 335 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf) 336 { 337 struct lp55xx_platform_data *pdata = chip->pdata; 338 int ret; 339 u8 status; 340 341 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status); 342 if (ret < 0) 343 return ret; 344 345 if (pdata->clock_mode != LP55XX_CLOCK_EXT) 346 return 0; 347 348 /* Check that ext clock is really in use if requested */ 349 if ((status & LP5521_EXT_CLK_USED) == 0) 350 return -EIO; 351 352 return 0; 353 } 354 355 static void lp5521_led_brightness_work(struct work_struct *work) 356 { 357 struct lp55xx_led *led = container_of(work, struct lp55xx_led, 358 brightness_work); 359 struct lp55xx_chip *chip = led->chip; 360 361 mutex_lock(&chip->lock); 362 lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr, 363 led->brightness); 364 mutex_unlock(&chip->lock); 365 } 366 367 static ssize_t lp5521_selftest(struct device *dev, 368 struct device_attribute *attr, 369 char *buf) 370 { 371 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 372 struct lp55xx_chip *chip = led->chip; 373 int ret; 374 375 mutex_lock(&chip->lock); 376 ret = lp5521_run_selftest(chip, buf); 377 mutex_unlock(&chip->lock); 378 379 return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK"); 380 } 381 382 /* device attributes */ 383 static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL); 384 385 static struct attribute *lp5521_attributes[] = { 386 &dev_attr_selftest.attr, 387 NULL 388 }; 389 390 static const struct attribute_group lp5521_group = { 391 .attrs = lp5521_attributes, 392 }; 393 394 /* Chip specific configurations */ 395 static struct lp55xx_device_config lp5521_cfg = { 396 .reset = { 397 .addr = LP5521_REG_RESET, 398 .val = LP5521_RESET, 399 }, 400 .enable = { 401 .addr = LP5521_REG_ENABLE, 402 .val = LP5521_ENABLE_DEFAULT, 403 }, 404 .max_channel = LP5521_MAX_LEDS, 405 .post_init_device = lp5521_post_init_device, 406 .brightness_work_fn = lp5521_led_brightness_work, 407 .set_led_current = lp5521_set_led_current, 408 .firmware_cb = lp5521_firmware_loaded, 409 .run_engine = lp5521_run_engine, 410 .dev_attr_group = &lp5521_group, 411 }; 412 413 static int lp5521_probe(struct i2c_client *client, 414 const struct i2c_device_id *id) 415 { 416 int ret; 417 struct lp55xx_chip *chip; 418 struct lp55xx_led *led; 419 struct lp55xx_platform_data *pdata = client->dev.platform_data; 420 421 if (!pdata) { 422 dev_err(&client->dev, "no platform data\n"); 423 return -EINVAL; 424 } 425 426 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 427 if (!chip) 428 return -ENOMEM; 429 430 led = devm_kzalloc(&client->dev, 431 sizeof(*led) * pdata->num_channels, GFP_KERNEL); 432 if (!led) 433 return -ENOMEM; 434 435 chip->cl = client; 436 chip->pdata = pdata; 437 chip->cfg = &lp5521_cfg; 438 439 mutex_init(&chip->lock); 440 441 i2c_set_clientdata(client, led); 442 443 ret = lp55xx_init_device(chip); 444 if (ret) 445 goto err_init; 446 447 dev_info(&client->dev, "%s programmable led chip found\n", id->name); 448 449 ret = lp55xx_register_leds(led, chip); 450 if (ret) 451 goto err_register_leds; 452 453 ret = lp55xx_register_sysfs(chip); 454 if (ret) { 455 dev_err(&client->dev, "registering sysfs failed\n"); 456 goto err_register_sysfs; 457 } 458 459 return 0; 460 461 err_register_sysfs: 462 lp55xx_unregister_leds(led, chip); 463 err_register_leds: 464 lp55xx_deinit_device(chip); 465 err_init: 466 return ret; 467 } 468 469 static int lp5521_remove(struct i2c_client *client) 470 { 471 struct lp55xx_led *led = i2c_get_clientdata(client); 472 struct lp55xx_chip *chip = led->chip; 473 474 lp5521_stop_engine(chip); 475 lp55xx_unregister_sysfs(chip); 476 lp55xx_unregister_leds(led, chip); 477 lp55xx_deinit_device(chip); 478 479 return 0; 480 } 481 482 static const struct i2c_device_id lp5521_id[] = { 483 { "lp5521", 0 }, /* Three channel chip */ 484 { } 485 }; 486 MODULE_DEVICE_TABLE(i2c, lp5521_id); 487 488 static struct i2c_driver lp5521_driver = { 489 .driver = { 490 .name = "lp5521", 491 }, 492 .probe = lp5521_probe, 493 .remove = lp5521_remove, 494 .id_table = lp5521_id, 495 }; 496 497 module_i2c_driver(lp5521_driver); 498 499 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo"); 500 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 501 MODULE_DESCRIPTION("LP5521 LED engine"); 502 MODULE_LICENSE("GPL v2"); 503