1 /* 2 * LP5521/LP5523/LP55231/LP5562 Common Driver 3 * 4 * Copyright 2012 Texas Instruments 5 * 6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * Derived from leds-lp5521.c, leds-lp5523.c 13 */ 14 15 #include <linux/clk.h> 16 #include <linux/delay.h> 17 #include <linux/firmware.h> 18 #include <linux/i2c.h> 19 #include <linux/leds.h> 20 #include <linux/module.h> 21 #include <linux/platform_data/leds-lp55xx.h> 22 #include <linux/slab.h> 23 #include <linux/gpio.h> 24 #include <linux/of_gpio.h> 25 26 #include "leds-lp55xx-common.h" 27 28 /* External clock rate */ 29 #define LP55XX_CLK_32K 32768 30 31 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev) 32 { 33 return container_of(cdev, struct lp55xx_led, cdev); 34 } 35 36 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev) 37 { 38 return cdev_to_lp55xx_led(dev_get_drvdata(dev)); 39 } 40 41 static void lp55xx_reset_device(struct lp55xx_chip *chip) 42 { 43 struct lp55xx_device_config *cfg = chip->cfg; 44 u8 addr = cfg->reset.addr; 45 u8 val = cfg->reset.val; 46 47 /* no error checking here because no ACK from the device after reset */ 48 lp55xx_write(chip, addr, val); 49 } 50 51 static int lp55xx_detect_device(struct lp55xx_chip *chip) 52 { 53 struct lp55xx_device_config *cfg = chip->cfg; 54 u8 addr = cfg->enable.addr; 55 u8 val = cfg->enable.val; 56 int ret; 57 58 ret = lp55xx_write(chip, addr, val); 59 if (ret) 60 return ret; 61 62 usleep_range(1000, 2000); 63 64 ret = lp55xx_read(chip, addr, &val); 65 if (ret) 66 return ret; 67 68 if (val != cfg->enable.val) 69 return -ENODEV; 70 71 return 0; 72 } 73 74 static int lp55xx_post_init_device(struct lp55xx_chip *chip) 75 { 76 struct lp55xx_device_config *cfg = chip->cfg; 77 78 if (!cfg->post_init_device) 79 return 0; 80 81 return cfg->post_init_device(chip); 82 } 83 84 static ssize_t lp55xx_show_current(struct device *dev, 85 struct device_attribute *attr, 86 char *buf) 87 { 88 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 89 90 return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current); 91 } 92 93 static ssize_t lp55xx_store_current(struct device *dev, 94 struct device_attribute *attr, 95 const char *buf, size_t len) 96 { 97 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 98 struct lp55xx_chip *chip = led->chip; 99 unsigned long curr; 100 101 if (kstrtoul(buf, 0, &curr)) 102 return -EINVAL; 103 104 if (curr > led->max_current) 105 return -EINVAL; 106 107 if (!chip->cfg->set_led_current) 108 return len; 109 110 mutex_lock(&chip->lock); 111 chip->cfg->set_led_current(led, (u8)curr); 112 mutex_unlock(&chip->lock); 113 114 return len; 115 } 116 117 static ssize_t lp55xx_show_max_current(struct device *dev, 118 struct device_attribute *attr, 119 char *buf) 120 { 121 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 122 123 return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current); 124 } 125 126 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current, 127 lp55xx_store_current); 128 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL); 129 130 static struct attribute *lp55xx_led_attributes[] = { 131 &dev_attr_led_current.attr, 132 &dev_attr_max_current.attr, 133 NULL, 134 }; 135 136 static struct attribute_group lp55xx_led_attr_group = { 137 .attrs = lp55xx_led_attributes 138 }; 139 140 static void lp55xx_set_brightness(struct led_classdev *cdev, 141 enum led_brightness brightness) 142 { 143 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev); 144 145 led->brightness = (u8)brightness; 146 schedule_work(&led->brightness_work); 147 } 148 149 static int lp55xx_init_led(struct lp55xx_led *led, 150 struct lp55xx_chip *chip, int chan) 151 { 152 struct lp55xx_platform_data *pdata = chip->pdata; 153 struct lp55xx_device_config *cfg = chip->cfg; 154 struct device *dev = &chip->cl->dev; 155 char name[32]; 156 int ret; 157 int max_channel = cfg->max_channel; 158 159 if (chan >= max_channel) { 160 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel); 161 return -EINVAL; 162 } 163 164 if (pdata->led_config[chan].led_current == 0) 165 return 0; 166 167 led->led_current = pdata->led_config[chan].led_current; 168 led->max_current = pdata->led_config[chan].max_current; 169 led->chan_nr = pdata->led_config[chan].chan_nr; 170 led->cdev.default_trigger = pdata->led_config[chan].default_trigger; 171 172 if (led->chan_nr >= max_channel) { 173 dev_err(dev, "Use channel numbers between 0 and %d\n", 174 max_channel - 1); 175 return -EINVAL; 176 } 177 178 led->cdev.brightness_set = lp55xx_set_brightness; 179 180 if (pdata->led_config[chan].name) { 181 led->cdev.name = pdata->led_config[chan].name; 182 } else { 183 snprintf(name, sizeof(name), "%s:channel%d", 184 pdata->label ? : chip->cl->name, chan); 185 led->cdev.name = name; 186 } 187 188 /* 189 * register led class device for each channel and 190 * add device attributes 191 */ 192 193 ret = led_classdev_register(dev, &led->cdev); 194 if (ret) { 195 dev_err(dev, "led register err: %d\n", ret); 196 return ret; 197 } 198 199 ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group); 200 if (ret) { 201 dev_err(dev, "led sysfs err: %d\n", ret); 202 led_classdev_unregister(&led->cdev); 203 return ret; 204 } 205 206 return 0; 207 } 208 209 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context) 210 { 211 struct lp55xx_chip *chip = context; 212 struct device *dev = &chip->cl->dev; 213 214 if (!fw) { 215 dev_err(dev, "firmware request failed\n"); 216 goto out; 217 } 218 219 /* handling firmware data is chip dependent */ 220 mutex_lock(&chip->lock); 221 222 chip->fw = fw; 223 if (chip->cfg->firmware_cb) 224 chip->cfg->firmware_cb(chip); 225 226 mutex_unlock(&chip->lock); 227 228 out: 229 /* firmware should be released for other channel use */ 230 release_firmware(chip->fw); 231 } 232 233 static int lp55xx_request_firmware(struct lp55xx_chip *chip) 234 { 235 const char *name = chip->cl->name; 236 struct device *dev = &chip->cl->dev; 237 238 return request_firmware_nowait(THIS_MODULE, true, name, dev, 239 GFP_KERNEL, chip, lp55xx_firmware_loaded); 240 } 241 242 static ssize_t lp55xx_show_engine_select(struct device *dev, 243 struct device_attribute *attr, 244 char *buf) 245 { 246 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 247 struct lp55xx_chip *chip = led->chip; 248 249 return sprintf(buf, "%d\n", chip->engine_idx); 250 } 251 252 static ssize_t lp55xx_store_engine_select(struct device *dev, 253 struct device_attribute *attr, 254 const char *buf, size_t len) 255 { 256 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 257 struct lp55xx_chip *chip = led->chip; 258 unsigned long val; 259 int ret; 260 261 if (kstrtoul(buf, 0, &val)) 262 return -EINVAL; 263 264 /* select the engine to be run */ 265 266 switch (val) { 267 case LP55XX_ENGINE_1: 268 case LP55XX_ENGINE_2: 269 case LP55XX_ENGINE_3: 270 mutex_lock(&chip->lock); 271 chip->engine_idx = val; 272 ret = lp55xx_request_firmware(chip); 273 mutex_unlock(&chip->lock); 274 break; 275 default: 276 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val); 277 return -EINVAL; 278 } 279 280 if (ret) { 281 dev_err(dev, "request firmware err: %d\n", ret); 282 return ret; 283 } 284 285 return len; 286 } 287 288 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start) 289 { 290 if (chip->cfg->run_engine) 291 chip->cfg->run_engine(chip, start); 292 } 293 294 static ssize_t lp55xx_store_engine_run(struct device *dev, 295 struct device_attribute *attr, 296 const char *buf, size_t len) 297 { 298 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 299 struct lp55xx_chip *chip = led->chip; 300 unsigned long val; 301 302 if (kstrtoul(buf, 0, &val)) 303 return -EINVAL; 304 305 /* run or stop the selected engine */ 306 307 if (val <= 0) { 308 lp55xx_run_engine(chip, false); 309 return len; 310 } 311 312 mutex_lock(&chip->lock); 313 lp55xx_run_engine(chip, true); 314 mutex_unlock(&chip->lock); 315 316 return len; 317 } 318 319 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR, 320 lp55xx_show_engine_select, lp55xx_store_engine_select); 321 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run); 322 323 static struct attribute *lp55xx_engine_attributes[] = { 324 &dev_attr_select_engine.attr, 325 &dev_attr_run_engine.attr, 326 NULL, 327 }; 328 329 static const struct attribute_group lp55xx_engine_attr_group = { 330 .attrs = lp55xx_engine_attributes, 331 }; 332 333 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val) 334 { 335 return i2c_smbus_write_byte_data(chip->cl, reg, val); 336 } 337 EXPORT_SYMBOL_GPL(lp55xx_write); 338 339 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val) 340 { 341 s32 ret; 342 343 ret = i2c_smbus_read_byte_data(chip->cl, reg); 344 if (ret < 0) 345 return ret; 346 347 *val = ret; 348 return 0; 349 } 350 EXPORT_SYMBOL_GPL(lp55xx_read); 351 352 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val) 353 { 354 int ret; 355 u8 tmp; 356 357 ret = lp55xx_read(chip, reg, &tmp); 358 if (ret) 359 return ret; 360 361 tmp &= ~mask; 362 tmp |= val & mask; 363 364 return lp55xx_write(chip, reg, tmp); 365 } 366 EXPORT_SYMBOL_GPL(lp55xx_update_bits); 367 368 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip) 369 { 370 struct clk *clk; 371 int err; 372 373 clk = devm_clk_get(&chip->cl->dev, "32k_clk"); 374 if (IS_ERR(clk)) 375 goto use_internal_clk; 376 377 err = clk_prepare_enable(clk); 378 if (err) 379 goto use_internal_clk; 380 381 if (clk_get_rate(clk) != LP55XX_CLK_32K) { 382 clk_disable_unprepare(clk); 383 goto use_internal_clk; 384 } 385 386 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K); 387 388 chip->clk = clk; 389 return true; 390 391 use_internal_clk: 392 dev_info(&chip->cl->dev, "internal clock used\n"); 393 return false; 394 } 395 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used); 396 397 int lp55xx_init_device(struct lp55xx_chip *chip) 398 { 399 struct lp55xx_platform_data *pdata; 400 struct lp55xx_device_config *cfg; 401 struct device *dev = &chip->cl->dev; 402 int ret = 0; 403 404 WARN_ON(!chip); 405 406 pdata = chip->pdata; 407 cfg = chip->cfg; 408 409 if (!pdata || !cfg) 410 return -EINVAL; 411 412 if (gpio_is_valid(pdata->enable_gpio)) { 413 ret = devm_gpio_request_one(dev, pdata->enable_gpio, 414 GPIOF_DIR_OUT, "lp5523_enable"); 415 if (ret < 0) { 416 dev_err(dev, "could not acquire enable gpio (err=%d)\n", 417 ret); 418 goto err; 419 } 420 421 gpio_set_value(pdata->enable_gpio, 0); 422 usleep_range(1000, 2000); /* Keep enable down at least 1ms */ 423 gpio_set_value(pdata->enable_gpio, 1); 424 usleep_range(1000, 2000); /* 500us abs min. */ 425 } 426 427 lp55xx_reset_device(chip); 428 429 /* 430 * Exact value is not available. 10 - 20ms 431 * appears to be enough for reset. 432 */ 433 usleep_range(10000, 20000); 434 435 ret = lp55xx_detect_device(chip); 436 if (ret) { 437 dev_err(dev, "device detection err: %d\n", ret); 438 goto err; 439 } 440 441 /* chip specific initialization */ 442 ret = lp55xx_post_init_device(chip); 443 if (ret) { 444 dev_err(dev, "post init device err: %d\n", ret); 445 goto err_post_init; 446 } 447 448 return 0; 449 450 err_post_init: 451 lp55xx_deinit_device(chip); 452 err: 453 return ret; 454 } 455 EXPORT_SYMBOL_GPL(lp55xx_init_device); 456 457 void lp55xx_deinit_device(struct lp55xx_chip *chip) 458 { 459 struct lp55xx_platform_data *pdata = chip->pdata; 460 461 if (chip->clk) 462 clk_disable_unprepare(chip->clk); 463 464 if (gpio_is_valid(pdata->enable_gpio)) 465 gpio_set_value(pdata->enable_gpio, 0); 466 } 467 EXPORT_SYMBOL_GPL(lp55xx_deinit_device); 468 469 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 470 { 471 struct lp55xx_platform_data *pdata = chip->pdata; 472 struct lp55xx_device_config *cfg = chip->cfg; 473 int num_channels = pdata->num_channels; 474 struct lp55xx_led *each; 475 u8 led_current; 476 int ret; 477 int i; 478 479 if (!cfg->brightness_work_fn) { 480 dev_err(&chip->cl->dev, "empty brightness configuration\n"); 481 return -EINVAL; 482 } 483 484 for (i = 0; i < num_channels; i++) { 485 486 /* do not initialize channels that are not connected */ 487 if (pdata->led_config[i].led_current == 0) 488 continue; 489 490 led_current = pdata->led_config[i].led_current; 491 each = led + i; 492 ret = lp55xx_init_led(each, chip, i); 493 if (ret) 494 goto err_init_led; 495 496 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn); 497 498 chip->num_leds++; 499 each->chip = chip; 500 501 /* setting led current at each channel */ 502 if (cfg->set_led_current) 503 cfg->set_led_current(each, led_current); 504 } 505 506 return 0; 507 508 err_init_led: 509 lp55xx_unregister_leds(led, chip); 510 return ret; 511 } 512 EXPORT_SYMBOL_GPL(lp55xx_register_leds); 513 514 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 515 { 516 int i; 517 struct lp55xx_led *each; 518 519 for (i = 0; i < chip->num_leds; i++) { 520 each = led + i; 521 led_classdev_unregister(&each->cdev); 522 flush_work(&each->brightness_work); 523 } 524 } 525 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds); 526 527 int lp55xx_register_sysfs(struct lp55xx_chip *chip) 528 { 529 struct device *dev = &chip->cl->dev; 530 struct lp55xx_device_config *cfg = chip->cfg; 531 int ret; 532 533 if (!cfg->run_engine || !cfg->firmware_cb) 534 goto dev_specific_attrs; 535 536 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group); 537 if (ret) 538 return ret; 539 540 dev_specific_attrs: 541 return cfg->dev_attr_group ? 542 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0; 543 } 544 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs); 545 546 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip) 547 { 548 struct device *dev = &chip->cl->dev; 549 struct lp55xx_device_config *cfg = chip->cfg; 550 551 if (cfg->dev_attr_group) 552 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group); 553 554 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group); 555 } 556 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs); 557 558 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np) 559 { 560 struct device_node *child; 561 struct lp55xx_platform_data *pdata; 562 struct lp55xx_led_config *cfg; 563 int num_channels; 564 int i = 0; 565 566 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 567 if (!pdata) 568 return -ENOMEM; 569 570 num_channels = of_get_child_count(np); 571 if (num_channels == 0) { 572 dev_err(dev, "no LED channels\n"); 573 return -EINVAL; 574 } 575 576 cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL); 577 if (!cfg) 578 return -ENOMEM; 579 580 pdata->led_config = &cfg[0]; 581 pdata->num_channels = num_channels; 582 583 for_each_child_of_node(np, child) { 584 cfg[i].chan_nr = i; 585 586 of_property_read_string(child, "chan-name", &cfg[i].name); 587 of_property_read_u8(child, "led-cur", &cfg[i].led_current); 588 of_property_read_u8(child, "max-cur", &cfg[i].max_current); 589 cfg[i].default_trigger = 590 of_get_property(child, "linux,default-trigger", NULL); 591 592 i++; 593 } 594 595 of_property_read_string(np, "label", &pdata->label); 596 of_property_read_u8(np, "clock-mode", &pdata->clock_mode); 597 598 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0); 599 600 /* LP8501 specific */ 601 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel); 602 603 dev->platform_data = pdata; 604 605 return 0; 606 } 607 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata); 608 609 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 610 MODULE_DESCRIPTION("LP55xx Common Driver"); 611 MODULE_LICENSE("GPL"); 612