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_attrs[] = { 131 &dev_attr_led_current.attr, 132 &dev_attr_max_current.attr, 133 NULL, 134 }; 135 ATTRIBUTE_GROUPS(lp55xx_led); 136 137 static void lp55xx_set_brightness(struct led_classdev *cdev, 138 enum led_brightness brightness) 139 { 140 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev); 141 142 led->brightness = (u8)brightness; 143 schedule_work(&led->brightness_work); 144 } 145 146 static int lp55xx_init_led(struct lp55xx_led *led, 147 struct lp55xx_chip *chip, int chan) 148 { 149 struct lp55xx_platform_data *pdata = chip->pdata; 150 struct lp55xx_device_config *cfg = chip->cfg; 151 struct device *dev = &chip->cl->dev; 152 char name[32]; 153 int ret; 154 int max_channel = cfg->max_channel; 155 156 if (chan >= max_channel) { 157 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel); 158 return -EINVAL; 159 } 160 161 if (pdata->led_config[chan].led_current == 0) 162 return 0; 163 164 led->led_current = pdata->led_config[chan].led_current; 165 led->max_current = pdata->led_config[chan].max_current; 166 led->chan_nr = pdata->led_config[chan].chan_nr; 167 led->cdev.default_trigger = pdata->led_config[chan].default_trigger; 168 169 if (led->chan_nr >= max_channel) { 170 dev_err(dev, "Use channel numbers between 0 and %d\n", 171 max_channel - 1); 172 return -EINVAL; 173 } 174 175 led->cdev.brightness_set = lp55xx_set_brightness; 176 led->cdev.groups = lp55xx_led_groups; 177 178 if (pdata->led_config[chan].name) { 179 led->cdev.name = pdata->led_config[chan].name; 180 } else { 181 snprintf(name, sizeof(name), "%s:channel%d", 182 pdata->label ? : chip->cl->name, chan); 183 led->cdev.name = name; 184 } 185 186 ret = led_classdev_register(dev, &led->cdev); 187 if (ret) { 188 dev_err(dev, "led register err: %d\n", ret); 189 return ret; 190 } 191 192 return 0; 193 } 194 195 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context) 196 { 197 struct lp55xx_chip *chip = context; 198 struct device *dev = &chip->cl->dev; 199 enum lp55xx_engine_index idx = chip->engine_idx; 200 201 if (!fw) { 202 dev_err(dev, "firmware request failed\n"); 203 goto out; 204 } 205 206 /* handling firmware data is chip dependent */ 207 mutex_lock(&chip->lock); 208 209 chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD; 210 chip->fw = fw; 211 if (chip->cfg->firmware_cb) 212 chip->cfg->firmware_cb(chip); 213 214 mutex_unlock(&chip->lock); 215 216 out: 217 /* firmware should be released for other channel use */ 218 release_firmware(chip->fw); 219 } 220 221 static int lp55xx_request_firmware(struct lp55xx_chip *chip) 222 { 223 const char *name = chip->cl->name; 224 struct device *dev = &chip->cl->dev; 225 226 return request_firmware_nowait(THIS_MODULE, true, name, dev, 227 GFP_KERNEL, chip, lp55xx_firmware_loaded); 228 } 229 230 static ssize_t lp55xx_show_engine_select(struct device *dev, 231 struct device_attribute *attr, 232 char *buf) 233 { 234 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 235 struct lp55xx_chip *chip = led->chip; 236 237 return sprintf(buf, "%d\n", chip->engine_idx); 238 } 239 240 static ssize_t lp55xx_store_engine_select(struct device *dev, 241 struct device_attribute *attr, 242 const char *buf, size_t len) 243 { 244 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 245 struct lp55xx_chip *chip = led->chip; 246 unsigned long val; 247 int ret; 248 249 if (kstrtoul(buf, 0, &val)) 250 return -EINVAL; 251 252 /* select the engine to be run */ 253 254 switch (val) { 255 case LP55XX_ENGINE_1: 256 case LP55XX_ENGINE_2: 257 case LP55XX_ENGINE_3: 258 mutex_lock(&chip->lock); 259 chip->engine_idx = val; 260 ret = lp55xx_request_firmware(chip); 261 mutex_unlock(&chip->lock); 262 break; 263 default: 264 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val); 265 return -EINVAL; 266 } 267 268 if (ret) { 269 dev_err(dev, "request firmware err: %d\n", ret); 270 return ret; 271 } 272 273 return len; 274 } 275 276 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start) 277 { 278 if (chip->cfg->run_engine) 279 chip->cfg->run_engine(chip, start); 280 } 281 282 static ssize_t lp55xx_store_engine_run(struct device *dev, 283 struct device_attribute *attr, 284 const char *buf, size_t len) 285 { 286 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 287 struct lp55xx_chip *chip = led->chip; 288 unsigned long val; 289 290 if (kstrtoul(buf, 0, &val)) 291 return -EINVAL; 292 293 /* run or stop the selected engine */ 294 295 if (val <= 0) { 296 lp55xx_run_engine(chip, false); 297 return len; 298 } 299 300 mutex_lock(&chip->lock); 301 lp55xx_run_engine(chip, true); 302 mutex_unlock(&chip->lock); 303 304 return len; 305 } 306 307 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR, 308 lp55xx_show_engine_select, lp55xx_store_engine_select); 309 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run); 310 311 static struct attribute *lp55xx_engine_attributes[] = { 312 &dev_attr_select_engine.attr, 313 &dev_attr_run_engine.attr, 314 NULL, 315 }; 316 317 static const struct attribute_group lp55xx_engine_attr_group = { 318 .attrs = lp55xx_engine_attributes, 319 }; 320 321 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val) 322 { 323 return i2c_smbus_write_byte_data(chip->cl, reg, val); 324 } 325 EXPORT_SYMBOL_GPL(lp55xx_write); 326 327 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val) 328 { 329 s32 ret; 330 331 ret = i2c_smbus_read_byte_data(chip->cl, reg); 332 if (ret < 0) 333 return ret; 334 335 *val = ret; 336 return 0; 337 } 338 EXPORT_SYMBOL_GPL(lp55xx_read); 339 340 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val) 341 { 342 int ret; 343 u8 tmp; 344 345 ret = lp55xx_read(chip, reg, &tmp); 346 if (ret) 347 return ret; 348 349 tmp &= ~mask; 350 tmp |= val & mask; 351 352 return lp55xx_write(chip, reg, tmp); 353 } 354 EXPORT_SYMBOL_GPL(lp55xx_update_bits); 355 356 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip) 357 { 358 struct clk *clk; 359 int err; 360 361 clk = devm_clk_get(&chip->cl->dev, "32k_clk"); 362 if (IS_ERR(clk)) 363 goto use_internal_clk; 364 365 err = clk_prepare_enable(clk); 366 if (err) 367 goto use_internal_clk; 368 369 if (clk_get_rate(clk) != LP55XX_CLK_32K) { 370 clk_disable_unprepare(clk); 371 goto use_internal_clk; 372 } 373 374 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K); 375 376 chip->clk = clk; 377 return true; 378 379 use_internal_clk: 380 dev_info(&chip->cl->dev, "internal clock used\n"); 381 return false; 382 } 383 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used); 384 385 int lp55xx_init_device(struct lp55xx_chip *chip) 386 { 387 struct lp55xx_platform_data *pdata; 388 struct lp55xx_device_config *cfg; 389 struct device *dev = &chip->cl->dev; 390 int ret = 0; 391 392 WARN_ON(!chip); 393 394 pdata = chip->pdata; 395 cfg = chip->cfg; 396 397 if (!pdata || !cfg) 398 return -EINVAL; 399 400 if (gpio_is_valid(pdata->enable_gpio)) { 401 ret = devm_gpio_request_one(dev, pdata->enable_gpio, 402 GPIOF_DIR_OUT, "lp5523_enable"); 403 if (ret < 0) { 404 dev_err(dev, "could not acquire enable gpio (err=%d)\n", 405 ret); 406 goto err; 407 } 408 409 gpio_set_value(pdata->enable_gpio, 0); 410 usleep_range(1000, 2000); /* Keep enable down at least 1ms */ 411 gpio_set_value(pdata->enable_gpio, 1); 412 usleep_range(1000, 2000); /* 500us abs min. */ 413 } 414 415 lp55xx_reset_device(chip); 416 417 /* 418 * Exact value is not available. 10 - 20ms 419 * appears to be enough for reset. 420 */ 421 usleep_range(10000, 20000); 422 423 ret = lp55xx_detect_device(chip); 424 if (ret) { 425 dev_err(dev, "device detection err: %d\n", ret); 426 goto err; 427 } 428 429 /* chip specific initialization */ 430 ret = lp55xx_post_init_device(chip); 431 if (ret) { 432 dev_err(dev, "post init device err: %d\n", ret); 433 goto err_post_init; 434 } 435 436 return 0; 437 438 err_post_init: 439 lp55xx_deinit_device(chip); 440 err: 441 return ret; 442 } 443 EXPORT_SYMBOL_GPL(lp55xx_init_device); 444 445 void lp55xx_deinit_device(struct lp55xx_chip *chip) 446 { 447 struct lp55xx_platform_data *pdata = chip->pdata; 448 449 if (chip->clk) 450 clk_disable_unprepare(chip->clk); 451 452 if (gpio_is_valid(pdata->enable_gpio)) 453 gpio_set_value(pdata->enable_gpio, 0); 454 } 455 EXPORT_SYMBOL_GPL(lp55xx_deinit_device); 456 457 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 458 { 459 struct lp55xx_platform_data *pdata = chip->pdata; 460 struct lp55xx_device_config *cfg = chip->cfg; 461 int num_channels = pdata->num_channels; 462 struct lp55xx_led *each; 463 u8 led_current; 464 int ret; 465 int i; 466 467 if (!cfg->brightness_work_fn) { 468 dev_err(&chip->cl->dev, "empty brightness configuration\n"); 469 return -EINVAL; 470 } 471 472 for (i = 0; i < num_channels; i++) { 473 474 /* do not initialize channels that are not connected */ 475 if (pdata->led_config[i].led_current == 0) 476 continue; 477 478 led_current = pdata->led_config[i].led_current; 479 each = led + i; 480 ret = lp55xx_init_led(each, chip, i); 481 if (ret) 482 goto err_init_led; 483 484 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn); 485 486 chip->num_leds++; 487 each->chip = chip; 488 489 /* setting led current at each channel */ 490 if (cfg->set_led_current) 491 cfg->set_led_current(each, led_current); 492 } 493 494 return 0; 495 496 err_init_led: 497 lp55xx_unregister_leds(led, chip); 498 return ret; 499 } 500 EXPORT_SYMBOL_GPL(lp55xx_register_leds); 501 502 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 503 { 504 int i; 505 struct lp55xx_led *each; 506 507 for (i = 0; i < chip->num_leds; i++) { 508 each = led + i; 509 led_classdev_unregister(&each->cdev); 510 flush_work(&each->brightness_work); 511 } 512 } 513 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds); 514 515 int lp55xx_register_sysfs(struct lp55xx_chip *chip) 516 { 517 struct device *dev = &chip->cl->dev; 518 struct lp55xx_device_config *cfg = chip->cfg; 519 int ret; 520 521 if (!cfg->run_engine || !cfg->firmware_cb) 522 goto dev_specific_attrs; 523 524 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group); 525 if (ret) 526 return ret; 527 528 dev_specific_attrs: 529 return cfg->dev_attr_group ? 530 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0; 531 } 532 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs); 533 534 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip) 535 { 536 struct device *dev = &chip->cl->dev; 537 struct lp55xx_device_config *cfg = chip->cfg; 538 539 if (cfg->dev_attr_group) 540 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group); 541 542 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group); 543 } 544 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs); 545 546 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np) 547 { 548 struct device_node *child; 549 struct lp55xx_platform_data *pdata; 550 struct lp55xx_led_config *cfg; 551 int num_channels; 552 int i = 0; 553 554 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 555 if (!pdata) 556 return -ENOMEM; 557 558 num_channels = of_get_child_count(np); 559 if (num_channels == 0) { 560 dev_err(dev, "no LED channels\n"); 561 return -EINVAL; 562 } 563 564 cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL); 565 if (!cfg) 566 return -ENOMEM; 567 568 pdata->led_config = &cfg[0]; 569 pdata->num_channels = num_channels; 570 571 for_each_child_of_node(np, child) { 572 cfg[i].chan_nr = i; 573 574 of_property_read_string(child, "chan-name", &cfg[i].name); 575 of_property_read_u8(child, "led-cur", &cfg[i].led_current); 576 of_property_read_u8(child, "max-cur", &cfg[i].max_current); 577 cfg[i].default_trigger = 578 of_get_property(child, "linux,default-trigger", NULL); 579 580 i++; 581 } 582 583 of_property_read_string(np, "label", &pdata->label); 584 of_property_read_u8(np, "clock-mode", &pdata->clock_mode); 585 586 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0); 587 588 /* LP8501 specific */ 589 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel); 590 591 dev->platform_data = pdata; 592 593 return 0; 594 } 595 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata); 596 597 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 598 MODULE_DESCRIPTION("LP55xx Common Driver"); 599 MODULE_LICENSE("GPL"); 600