1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc. 4 * 5 * Author: Nate Case <ncase@xes-inc.com> 6 * 7 * LED driver for various PCA955x I2C LED drivers 8 * 9 * Supported devices: 10 * 11 * Device Description 7-bit slave address 12 * ------ ----------- ------------------- 13 * PCA9550 2-bit driver 0x60 .. 0x61 14 * PCA9551 8-bit driver 0x60 .. 0x67 15 * PCA9552 16-bit driver 0x60 .. 0x67 16 * PCA9553/01 4-bit driver 0x62 17 * PCA9553/02 4-bit driver 0x63 18 * 19 * Philips PCA955x LED driver chips follow a register map as shown below: 20 * 21 * Control Register Description 22 * ---------------- ----------- 23 * 0x0 Input register 0 24 * .. 25 * NUM_INPUT_REGS - 1 Last Input register X 26 * 27 * NUM_INPUT_REGS Frequency prescaler 0 28 * NUM_INPUT_REGS + 1 PWM register 0 29 * NUM_INPUT_REGS + 2 Frequency prescaler 1 30 * NUM_INPUT_REGS + 3 PWM register 1 31 * 32 * NUM_INPUT_REGS + 4 LED selector 0 33 * NUM_INPUT_REGS + 4 34 * + NUM_LED_REGS - 1 Last LED selector 35 * 36 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many 37 * bits the chip supports. 38 */ 39 40 #include <linux/ctype.h> 41 #include <linux/delay.h> 42 #include <linux/err.h> 43 #include <linux/gpio/driver.h> 44 #include <linux/i2c.h> 45 #include <linux/leds.h> 46 #include <linux/module.h> 47 #include <linux/of.h> 48 #include <linux/property.h> 49 #include <linux/slab.h> 50 #include <linux/string.h> 51 52 #include <dt-bindings/leds/leds-pca955x.h> 53 54 /* LED select registers determine the source that drives LED outputs */ 55 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ 56 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ 57 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ 58 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ 59 60 #define PCA955X_GPIO_INPUT LED_OFF 61 #define PCA955X_GPIO_HIGH LED_OFF 62 #define PCA955X_GPIO_LOW LED_FULL 63 64 enum pca955x_type { 65 pca9550, 66 pca9551, 67 pca9552, 68 ibm_pca9552, 69 pca9553, 70 }; 71 72 struct pca955x_chipdef { 73 int bits; 74 u8 slv_addr; /* 7-bit slave address mask */ 75 int slv_addr_shift; /* Number of bits to ignore */ 76 }; 77 78 static struct pca955x_chipdef pca955x_chipdefs[] = { 79 [pca9550] = { 80 .bits = 2, 81 .slv_addr = /* 110000x */ 0x60, 82 .slv_addr_shift = 1, 83 }, 84 [pca9551] = { 85 .bits = 8, 86 .slv_addr = /* 1100xxx */ 0x60, 87 .slv_addr_shift = 3, 88 }, 89 [pca9552] = { 90 .bits = 16, 91 .slv_addr = /* 1100xxx */ 0x60, 92 .slv_addr_shift = 3, 93 }, 94 [ibm_pca9552] = { 95 .bits = 16, 96 .slv_addr = /* 0110xxx */ 0x30, 97 .slv_addr_shift = 3, 98 }, 99 [pca9553] = { 100 .bits = 4, 101 .slv_addr = /* 110001x */ 0x62, 102 .slv_addr_shift = 1, 103 }, 104 }; 105 106 static const struct i2c_device_id pca955x_id[] = { 107 { "pca9550", pca9550 }, 108 { "pca9551", pca9551 }, 109 { "pca9552", pca9552 }, 110 { "ibm-pca9552", ibm_pca9552 }, 111 { "pca9553", pca9553 }, 112 { } 113 }; 114 MODULE_DEVICE_TABLE(i2c, pca955x_id); 115 116 struct pca955x { 117 struct mutex lock; 118 struct pca955x_led *leds; 119 struct pca955x_chipdef *chipdef; 120 struct i2c_client *client; 121 #ifdef CONFIG_LEDS_PCA955X_GPIO 122 struct gpio_chip gpio; 123 #endif 124 }; 125 126 struct pca955x_led { 127 struct pca955x *pca955x; 128 struct led_classdev led_cdev; 129 int led_num; /* 0 .. 15 potentially */ 130 u32 type; 131 int default_state; 132 struct fwnode_handle *fwnode; 133 }; 134 135 struct pca955x_platform_data { 136 struct pca955x_led *leds; 137 int num_leds; 138 }; 139 140 /* 8 bits per input register */ 141 static inline int pca95xx_num_input_regs(int bits) 142 { 143 return (bits + 7) / 8; 144 } 145 146 /* 4 bits per LED selector register */ 147 static inline int pca95xx_num_led_regs(int bits) 148 { 149 return (bits + 3) / 4; 150 } 151 152 /* 153 * Return an LED selector register value based on an existing one, with 154 * the appropriate 2-bit state value set for the given LED number (0-3). 155 */ 156 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) 157 { 158 return (oldval & (~(0x3 << (led_num << 1)))) | 159 ((state & 0x3) << (led_num << 1)); 160 } 161 162 /* 163 * Write to frequency prescaler register, used to program the 164 * period of the PWM output. period = (PSCx + 1) / 38 165 */ 166 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) 167 { 168 struct pca955x *pca955x = i2c_get_clientdata(client); 169 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n); 170 int ret; 171 172 ret = i2c_smbus_write_byte_data(client, cmd, val); 173 if (ret < 0) 174 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 175 __func__, n, val, ret); 176 return ret; 177 } 178 179 /* 180 * Write to PWM register, which determines the duty cycle of the 181 * output. LED is OFF when the count is less than the value of this 182 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 183 * 184 * Duty cycle is (256 - PWMx) / 256 185 */ 186 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 187 { 188 struct pca955x *pca955x = i2c_get_clientdata(client); 189 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 190 int ret; 191 192 ret = i2c_smbus_write_byte_data(client, cmd, val); 193 if (ret < 0) 194 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 195 __func__, n, val, ret); 196 return ret; 197 } 198 199 /* 200 * Write to LED selector register, which determines the source that 201 * drives the LED output. 202 */ 203 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 204 { 205 struct pca955x *pca955x = i2c_get_clientdata(client); 206 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 207 int ret; 208 209 ret = i2c_smbus_write_byte_data(client, cmd, val); 210 if (ret < 0) 211 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 212 __func__, n, val, ret); 213 return ret; 214 } 215 216 /* 217 * Read the LED selector register, which determines the source that 218 * drives the LED output. 219 */ 220 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) 221 { 222 struct pca955x *pca955x = i2c_get_clientdata(client); 223 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 224 int ret; 225 226 ret = i2c_smbus_read_byte_data(client, cmd); 227 if (ret < 0) { 228 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 229 __func__, n, ret); 230 return ret; 231 } 232 *val = (u8)ret; 233 return 0; 234 } 235 236 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val) 237 { 238 struct pca955x *pca955x = i2c_get_clientdata(client); 239 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 240 int ret; 241 242 ret = i2c_smbus_read_byte_data(client, cmd); 243 if (ret < 0) { 244 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 245 __func__, n, ret); 246 return ret; 247 } 248 *val = (u8)ret; 249 return 0; 250 } 251 252 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev) 253 { 254 struct pca955x_led *pca955x_led = container_of(led_cdev, 255 struct pca955x_led, 256 led_cdev); 257 struct pca955x *pca955x = pca955x_led->pca955x; 258 u8 ls, pwm; 259 int ret; 260 261 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls); 262 if (ret) 263 return ret; 264 265 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3; 266 switch (ls) { 267 case PCA955X_LS_LED_ON: 268 ret = LED_FULL; 269 break; 270 case PCA955X_LS_LED_OFF: 271 ret = LED_OFF; 272 break; 273 case PCA955X_LS_BLINK0: 274 ret = LED_HALF; 275 break; 276 case PCA955X_LS_BLINK1: 277 ret = pca955x_read_pwm(pca955x->client, 1, &pwm); 278 if (ret) 279 return ret; 280 ret = 255 - pwm; 281 break; 282 } 283 284 return ret; 285 } 286 287 static int pca955x_led_set(struct led_classdev *led_cdev, 288 enum led_brightness value) 289 { 290 struct pca955x_led *pca955x_led; 291 struct pca955x *pca955x; 292 u8 ls; 293 int chip_ls; /* which LSx to use (0-3 potentially) */ 294 int ls_led; /* which set of bits within LSx to use (0-3) */ 295 int ret; 296 297 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 298 pca955x = pca955x_led->pca955x; 299 300 chip_ls = pca955x_led->led_num / 4; 301 ls_led = pca955x_led->led_num % 4; 302 303 mutex_lock(&pca955x->lock); 304 305 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 306 if (ret) 307 goto out; 308 309 switch (value) { 310 case LED_FULL: 311 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 312 break; 313 case LED_OFF: 314 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 315 break; 316 case LED_HALF: 317 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 318 break; 319 default: 320 /* 321 * Use PWM1 for all other values. This has the unwanted 322 * side effect of making all LEDs on the chip share the 323 * same brightness level if set to a value other than 324 * OFF, HALF, or FULL. But, this is probably better than 325 * just turning off for all other values. 326 */ 327 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 328 if (ret) 329 goto out; 330 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 331 break; 332 } 333 334 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 335 336 out: 337 mutex_unlock(&pca955x->lock); 338 339 return ret; 340 } 341 342 #ifdef CONFIG_LEDS_PCA955X_GPIO 343 /* 344 * Read the INPUT register, which contains the state of LEDs. 345 */ 346 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 347 { 348 int ret = i2c_smbus_read_byte_data(client, n); 349 350 if (ret < 0) { 351 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 352 __func__, n, ret); 353 return ret; 354 } 355 *val = (u8)ret; 356 return 0; 357 358 } 359 360 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 361 { 362 struct pca955x *pca955x = gpiochip_get_data(gc); 363 struct pca955x_led *led = &pca955x->leds[offset]; 364 365 if (led->type == PCA955X_TYPE_GPIO) 366 return 0; 367 368 return -EBUSY; 369 } 370 371 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 372 int val) 373 { 374 struct pca955x *pca955x = gpiochip_get_data(gc); 375 struct pca955x_led *led = &pca955x->leds[offset]; 376 377 if (val) 378 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 379 380 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 381 } 382 383 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 384 int val) 385 { 386 pca955x_set_value(gc, offset, val); 387 } 388 389 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 390 { 391 struct pca955x *pca955x = gpiochip_get_data(gc); 392 struct pca955x_led *led = &pca955x->leds[offset]; 393 u8 reg = 0; 394 395 /* There is nothing we can do about errors */ 396 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 397 398 return !!(reg & (1 << (led->led_num % 8))); 399 } 400 401 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 402 unsigned int offset) 403 { 404 struct pca955x *pca955x = gpiochip_get_data(gc); 405 struct pca955x_led *led = &pca955x->leds[offset]; 406 407 /* To use as input ensure pin is not driven. */ 408 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 409 } 410 411 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 412 unsigned int offset, int val) 413 { 414 return pca955x_set_value(gc, offset, val); 415 } 416 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 417 418 static struct pca955x_platform_data * 419 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) 420 { 421 struct pca955x_platform_data *pdata; 422 struct pca955x_led *led; 423 struct fwnode_handle *child; 424 int count; 425 426 count = device_get_child_node_count(&client->dev); 427 if (!count || count > chip->bits) 428 return ERR_PTR(-ENODEV); 429 430 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 431 if (!pdata) 432 return ERR_PTR(-ENOMEM); 433 434 pdata->leds = devm_kcalloc(&client->dev, 435 chip->bits, sizeof(struct pca955x_led), 436 GFP_KERNEL); 437 if (!pdata->leds) 438 return ERR_PTR(-ENOMEM); 439 440 device_for_each_child_node(&client->dev, child) { 441 const char *state; 442 u32 reg; 443 int res; 444 445 res = fwnode_property_read_u32(child, "reg", ®); 446 if ((res != 0) || (reg >= chip->bits)) 447 continue; 448 449 led = &pdata->leds[reg]; 450 led->type = PCA955X_TYPE_LED; 451 led->fwnode = child; 452 fwnode_property_read_u32(child, "type", &led->type); 453 454 if (!fwnode_property_read_string(child, "default-state", 455 &state)) { 456 if (!strcmp(state, "keep")) 457 led->default_state = LEDS_GPIO_DEFSTATE_KEEP; 458 else if (!strcmp(state, "on")) 459 led->default_state = LEDS_GPIO_DEFSTATE_ON; 460 else 461 led->default_state = LEDS_GPIO_DEFSTATE_OFF; 462 } else { 463 led->default_state = LEDS_GPIO_DEFSTATE_OFF; 464 } 465 } 466 467 pdata->num_leds = chip->bits; 468 469 return pdata; 470 } 471 472 static const struct of_device_id of_pca955x_match[] = { 473 { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, 474 { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, 475 { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, 476 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 }, 477 { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, 478 {}, 479 }; 480 MODULE_DEVICE_TABLE(of, of_pca955x_match); 481 482 static int pca955x_probe(struct i2c_client *client) 483 { 484 struct pca955x *pca955x; 485 struct pca955x_led *pca955x_led; 486 struct pca955x_chipdef *chip; 487 struct led_classdev *led; 488 struct led_init_data init_data; 489 struct i2c_adapter *adapter; 490 int i, err; 491 struct pca955x_platform_data *pdata; 492 int ngpios = 0; 493 bool set_default_label = false; 494 bool keep_pwm = false; 495 char default_label[8]; 496 enum pca955x_type chip_type; 497 const void *md = device_get_match_data(&client->dev); 498 499 if (md) { 500 chip_type = (enum pca955x_type)md; 501 } else { 502 const struct i2c_device_id *id = i2c_match_id(pca955x_id, 503 client); 504 505 if (id) { 506 chip_type = (enum pca955x_type)id->driver_data; 507 } else { 508 dev_err(&client->dev, "unknown chip\n"); 509 return -ENODEV; 510 } 511 } 512 513 chip = &pca955x_chipdefs[chip_type]; 514 adapter = client->adapter; 515 pdata = dev_get_platdata(&client->dev); 516 if (!pdata) { 517 pdata = pca955x_get_pdata(client, chip); 518 if (IS_ERR(pdata)) 519 return PTR_ERR(pdata); 520 } 521 522 /* Make sure the slave address / chip type combo given is possible */ 523 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 524 chip->slv_addr) { 525 dev_err(&client->dev, "invalid slave address %02x\n", 526 client->addr); 527 return -ENODEV; 528 } 529 530 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 531 "slave address 0x%02x\n", client->name, chip->bits, 532 client->addr); 533 534 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 535 return -EIO; 536 537 if (pdata->num_leds != chip->bits) { 538 dev_err(&client->dev, 539 "board info claims %d LEDs on a %d-bit chip\n", 540 pdata->num_leds, chip->bits); 541 return -ENODEV; 542 } 543 544 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 545 if (!pca955x) 546 return -ENOMEM; 547 548 pca955x->leds = devm_kcalloc(&client->dev, chip->bits, 549 sizeof(*pca955x_led), GFP_KERNEL); 550 if (!pca955x->leds) 551 return -ENOMEM; 552 553 i2c_set_clientdata(client, pca955x); 554 555 mutex_init(&pca955x->lock); 556 pca955x->client = client; 557 pca955x->chipdef = chip; 558 559 init_data.devname_mandatory = false; 560 init_data.devicename = "pca955x"; 561 562 for (i = 0; i < chip->bits; i++) { 563 pca955x_led = &pca955x->leds[i]; 564 pca955x_led->led_num = i; 565 pca955x_led->pca955x = pca955x; 566 pca955x_led->type = pdata->leds[i].type; 567 568 switch (pca955x_led->type) { 569 case PCA955X_TYPE_NONE: 570 break; 571 case PCA955X_TYPE_GPIO: 572 ngpios++; 573 break; 574 case PCA955X_TYPE_LED: 575 led = &pca955x_led->led_cdev; 576 led->brightness_set_blocking = pca955x_led_set; 577 led->brightness_get = pca955x_led_get; 578 579 if (pdata->leds[i].default_state == 580 LEDS_GPIO_DEFSTATE_OFF) { 581 err = pca955x_led_set(led, LED_OFF); 582 if (err) 583 return err; 584 } else if (pdata->leds[i].default_state == 585 LEDS_GPIO_DEFSTATE_ON) { 586 err = pca955x_led_set(led, LED_FULL); 587 if (err) 588 return err; 589 } 590 591 init_data.fwnode = pdata->leds[i].fwnode; 592 593 if (is_of_node(init_data.fwnode)) { 594 if (to_of_node(init_data.fwnode)->name[0] == 595 '\0') 596 set_default_label = true; 597 else 598 set_default_label = false; 599 } else { 600 set_default_label = true; 601 } 602 603 if (set_default_label) { 604 snprintf(default_label, sizeof(default_label), 605 "%d", i); 606 init_data.default_label = default_label; 607 } else { 608 init_data.default_label = NULL; 609 } 610 611 err = devm_led_classdev_register_ext(&client->dev, led, 612 &init_data); 613 if (err) 614 return err; 615 616 /* 617 * For default-state == "keep", let the core update the 618 * brightness from the hardware, then check the 619 * brightness to see if it's using PWM1. If so, PWM1 620 * should not be written below. 621 */ 622 if (pdata->leds[i].default_state == 623 LEDS_GPIO_DEFSTATE_KEEP) { 624 if (led->brightness != LED_FULL && 625 led->brightness != LED_OFF && 626 led->brightness != LED_HALF) 627 keep_pwm = true; 628 } 629 } 630 } 631 632 /* PWM0 is used for half brightness or 50% duty cycle */ 633 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 634 if (err) 635 return err; 636 637 if (!keep_pwm) { 638 /* PWM1 is used for variable brightness, default to OFF */ 639 err = pca955x_write_pwm(client, 1, 0); 640 if (err) 641 return err; 642 } 643 644 /* Set to fast frequency so we do not see flashing */ 645 err = pca955x_write_psc(client, 0, 0); 646 if (err) 647 return err; 648 err = pca955x_write_psc(client, 1, 0); 649 if (err) 650 return err; 651 652 #ifdef CONFIG_LEDS_PCA955X_GPIO 653 if (ngpios) { 654 pca955x->gpio.label = "gpio-pca955x"; 655 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 656 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 657 pca955x->gpio.set = pca955x_gpio_set_value; 658 pca955x->gpio.get = pca955x_gpio_get_value; 659 pca955x->gpio.request = pca955x_gpio_request_pin; 660 pca955x->gpio.can_sleep = 1; 661 pca955x->gpio.base = -1; 662 pca955x->gpio.ngpio = ngpios; 663 pca955x->gpio.parent = &client->dev; 664 pca955x->gpio.owner = THIS_MODULE; 665 666 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 667 pca955x); 668 if (err) { 669 /* Use data->gpio.dev as a flag for freeing gpiochip */ 670 pca955x->gpio.parent = NULL; 671 dev_warn(&client->dev, "could not add gpiochip\n"); 672 return err; 673 } 674 dev_info(&client->dev, "gpios %i...%i\n", 675 pca955x->gpio.base, pca955x->gpio.base + 676 pca955x->gpio.ngpio - 1); 677 } 678 #endif 679 680 return 0; 681 } 682 683 static struct i2c_driver pca955x_driver = { 684 .driver = { 685 .name = "leds-pca955x", 686 .of_match_table = of_pca955x_match, 687 }, 688 .probe_new = pca955x_probe, 689 .id_table = pca955x_id, 690 }; 691 692 module_i2c_driver(pca955x_driver); 693 694 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 695 MODULE_DESCRIPTION("PCA955x LED driver"); 696 MODULE_LICENSE("GPL v2"); 697