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/bitops.h> 41 #include <linux/ctype.h> 42 #include <linux/delay.h> 43 #include <linux/err.h> 44 #include <linux/gpio/driver.h> 45 #include <linux/i2c.h> 46 #include <linux/leds.h> 47 #include <linux/module.h> 48 #include <linux/of.h> 49 #include <linux/property.h> 50 #include <linux/slab.h> 51 #include <linux/string.h> 52 53 #include <dt-bindings/leds/leds-pca955x.h> 54 55 /* LED select registers determine the source that drives LED outputs */ 56 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ 57 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ 58 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ 59 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ 60 61 #define PCA955X_GPIO_INPUT LED_OFF 62 #define PCA955X_GPIO_HIGH LED_OFF 63 #define PCA955X_GPIO_LOW LED_FULL 64 65 enum pca955x_type { 66 pca9550, 67 pca9551, 68 pca9552, 69 ibm_pca9552, 70 pca9553, 71 }; 72 73 struct pca955x_chipdef { 74 int bits; 75 u8 slv_addr; /* 7-bit slave address mask */ 76 int slv_addr_shift; /* Number of bits to ignore */ 77 }; 78 79 static struct pca955x_chipdef pca955x_chipdefs[] = { 80 [pca9550] = { 81 .bits = 2, 82 .slv_addr = /* 110000x */ 0x60, 83 .slv_addr_shift = 1, 84 }, 85 [pca9551] = { 86 .bits = 8, 87 .slv_addr = /* 1100xxx */ 0x60, 88 .slv_addr_shift = 3, 89 }, 90 [pca9552] = { 91 .bits = 16, 92 .slv_addr = /* 1100xxx */ 0x60, 93 .slv_addr_shift = 3, 94 }, 95 [ibm_pca9552] = { 96 .bits = 16, 97 .slv_addr = /* 0110xxx */ 0x30, 98 .slv_addr_shift = 3, 99 }, 100 [pca9553] = { 101 .bits = 4, 102 .slv_addr = /* 110001x */ 0x62, 103 .slv_addr_shift = 1, 104 }, 105 }; 106 107 static const struct i2c_device_id pca955x_id[] = { 108 { "pca9550", pca9550 }, 109 { "pca9551", pca9551 }, 110 { "pca9552", pca9552 }, 111 { "ibm-pca9552", ibm_pca9552 }, 112 { "pca9553", pca9553 }, 113 { } 114 }; 115 MODULE_DEVICE_TABLE(i2c, pca955x_id); 116 117 struct pca955x { 118 struct mutex lock; 119 struct pca955x_led *leds; 120 struct pca955x_chipdef *chipdef; 121 struct i2c_client *client; 122 unsigned long active_pins; 123 #ifdef CONFIG_LEDS_PCA955X_GPIO 124 struct gpio_chip gpio; 125 #endif 126 }; 127 128 struct pca955x_led { 129 struct pca955x *pca955x; 130 struct led_classdev led_cdev; 131 int led_num; /* 0 .. 15 potentially */ 132 u32 type; 133 int default_state; 134 struct fwnode_handle *fwnode; 135 }; 136 137 struct pca955x_platform_data { 138 struct pca955x_led *leds; 139 int num_leds; 140 }; 141 142 /* 8 bits per input register */ 143 static inline int pca95xx_num_input_regs(int bits) 144 { 145 return (bits + 7) / 8; 146 } 147 148 /* 149 * Return an LED selector register value based on an existing one, with 150 * the appropriate 2-bit state value set for the given LED number (0-3). 151 */ 152 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) 153 { 154 return (oldval & (~(0x3 << (led_num << 1)))) | 155 ((state & 0x3) << (led_num << 1)); 156 } 157 158 /* 159 * Write to frequency prescaler register, used to program the 160 * period of the PWM output. period = (PSCx + 1) / 38 161 */ 162 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) 163 { 164 struct pca955x *pca955x = i2c_get_clientdata(client); 165 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n); 166 int ret; 167 168 ret = i2c_smbus_write_byte_data(client, cmd, val); 169 if (ret < 0) 170 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 171 __func__, n, val, ret); 172 return ret; 173 } 174 175 /* 176 * Write to PWM register, which determines the duty cycle of the 177 * output. LED is OFF when the count is less than the value of this 178 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 179 * 180 * Duty cycle is (256 - PWMx) / 256 181 */ 182 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 183 { 184 struct pca955x *pca955x = i2c_get_clientdata(client); 185 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 186 int ret; 187 188 ret = i2c_smbus_write_byte_data(client, cmd, val); 189 if (ret < 0) 190 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 191 __func__, n, val, ret); 192 return ret; 193 } 194 195 /* 196 * Write to LED selector register, which determines the source that 197 * drives the LED output. 198 */ 199 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 200 { 201 struct pca955x *pca955x = i2c_get_clientdata(client); 202 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 203 int ret; 204 205 ret = i2c_smbus_write_byte_data(client, cmd, val); 206 if (ret < 0) 207 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 208 __func__, n, val, ret); 209 return ret; 210 } 211 212 /* 213 * Read the LED selector register, which determines the source that 214 * drives the LED output. 215 */ 216 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) 217 { 218 struct pca955x *pca955x = i2c_get_clientdata(client); 219 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 220 int ret; 221 222 ret = i2c_smbus_read_byte_data(client, cmd); 223 if (ret < 0) { 224 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 225 __func__, n, ret); 226 return ret; 227 } 228 *val = (u8)ret; 229 return 0; 230 } 231 232 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val) 233 { 234 struct pca955x *pca955x = i2c_get_clientdata(client); 235 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 236 int ret; 237 238 ret = i2c_smbus_read_byte_data(client, cmd); 239 if (ret < 0) { 240 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 241 __func__, n, ret); 242 return ret; 243 } 244 *val = (u8)ret; 245 return 0; 246 } 247 248 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev) 249 { 250 struct pca955x_led *pca955x_led = container_of(led_cdev, 251 struct pca955x_led, 252 led_cdev); 253 struct pca955x *pca955x = pca955x_led->pca955x; 254 u8 ls, pwm; 255 int ret; 256 257 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls); 258 if (ret) 259 return ret; 260 261 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3; 262 switch (ls) { 263 case PCA955X_LS_LED_ON: 264 ret = LED_FULL; 265 break; 266 case PCA955X_LS_LED_OFF: 267 ret = LED_OFF; 268 break; 269 case PCA955X_LS_BLINK0: 270 ret = LED_HALF; 271 break; 272 case PCA955X_LS_BLINK1: 273 ret = pca955x_read_pwm(pca955x->client, 1, &pwm); 274 if (ret) 275 return ret; 276 ret = 255 - pwm; 277 break; 278 } 279 280 return ret; 281 } 282 283 static int pca955x_led_set(struct led_classdev *led_cdev, 284 enum led_brightness value) 285 { 286 struct pca955x_led *pca955x_led; 287 struct pca955x *pca955x; 288 u8 ls; 289 int chip_ls; /* which LSx to use (0-3 potentially) */ 290 int ls_led; /* which set of bits within LSx to use (0-3) */ 291 int ret; 292 293 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 294 pca955x = pca955x_led->pca955x; 295 296 chip_ls = pca955x_led->led_num / 4; 297 ls_led = pca955x_led->led_num % 4; 298 299 mutex_lock(&pca955x->lock); 300 301 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 302 if (ret) 303 goto out; 304 305 switch (value) { 306 case LED_FULL: 307 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 308 break; 309 case LED_OFF: 310 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 311 break; 312 case LED_HALF: 313 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 314 break; 315 default: 316 /* 317 * Use PWM1 for all other values. This has the unwanted 318 * side effect of making all LEDs on the chip share the 319 * same brightness level if set to a value other than 320 * OFF, HALF, or FULL. But, this is probably better than 321 * just turning off for all other values. 322 */ 323 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 324 if (ret) 325 goto out; 326 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 327 break; 328 } 329 330 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 331 332 out: 333 mutex_unlock(&pca955x->lock); 334 335 return ret; 336 } 337 338 #ifdef CONFIG_LEDS_PCA955X_GPIO 339 /* 340 * Read the INPUT register, which contains the state of LEDs. 341 */ 342 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 343 { 344 int ret = i2c_smbus_read_byte_data(client, n); 345 346 if (ret < 0) { 347 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 348 __func__, n, ret); 349 return ret; 350 } 351 *val = (u8)ret; 352 return 0; 353 354 } 355 356 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 357 { 358 struct pca955x *pca955x = gpiochip_get_data(gc); 359 360 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0; 361 } 362 363 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset) 364 { 365 struct pca955x *pca955x = gpiochip_get_data(gc); 366 367 clear_bit(offset, &pca955x->active_pins); 368 } 369 370 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 371 int val) 372 { 373 struct pca955x *pca955x = gpiochip_get_data(gc); 374 struct pca955x_led *led = &pca955x->leds[offset]; 375 376 if (val) 377 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 378 379 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 380 } 381 382 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 383 int val) 384 { 385 pca955x_set_value(gc, offset, val); 386 } 387 388 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 389 { 390 struct pca955x *pca955x = gpiochip_get_data(gc); 391 struct pca955x_led *led = &pca955x->leds[offset]; 392 u8 reg = 0; 393 394 /* There is nothing we can do about errors */ 395 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 396 397 return !!(reg & (1 << (led->led_num % 8))); 398 } 399 400 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 401 unsigned int offset) 402 { 403 struct pca955x *pca955x = gpiochip_get_data(gc); 404 struct pca955x_led *led = &pca955x->leds[offset]; 405 406 /* To use as input ensure pin is not driven. */ 407 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 408 } 409 410 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 411 unsigned int offset, int val) 412 { 413 return pca955x_set_value(gc, offset, val); 414 } 415 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 416 417 static struct pca955x_platform_data * 418 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) 419 { 420 struct pca955x_platform_data *pdata; 421 struct pca955x_led *led; 422 struct fwnode_handle *child; 423 int count; 424 425 count = device_get_child_node_count(&client->dev); 426 if (count > chip->bits) 427 return ERR_PTR(-ENODEV); 428 429 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 430 if (!pdata) 431 return ERR_PTR(-ENOMEM); 432 433 pdata->leds = devm_kcalloc(&client->dev, 434 chip->bits, sizeof(struct pca955x_led), 435 GFP_KERNEL); 436 if (!pdata->leds) 437 return ERR_PTR(-ENOMEM); 438 439 device_for_each_child_node(&client->dev, child) { 440 const char *state; 441 u32 reg; 442 int res; 443 444 res = fwnode_property_read_u32(child, "reg", ®); 445 if ((res != 0) || (reg >= chip->bits)) 446 continue; 447 448 led = &pdata->leds[reg]; 449 led->type = PCA955X_TYPE_LED; 450 led->fwnode = child; 451 fwnode_property_read_u32(child, "type", &led->type); 452 453 if (!fwnode_property_read_string(child, "default-state", 454 &state)) { 455 if (!strcmp(state, "keep")) 456 led->default_state = LEDS_GPIO_DEFSTATE_KEEP; 457 else if (!strcmp(state, "on")) 458 led->default_state = LEDS_GPIO_DEFSTATE_ON; 459 else 460 led->default_state = LEDS_GPIO_DEFSTATE_OFF; 461 } else { 462 led->default_state = LEDS_GPIO_DEFSTATE_OFF; 463 } 464 } 465 466 pdata->num_leds = chip->bits; 467 468 return pdata; 469 } 470 471 static const struct of_device_id of_pca955x_match[] = { 472 { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, 473 { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, 474 { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, 475 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 }, 476 { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, 477 {}, 478 }; 479 MODULE_DEVICE_TABLE(of, of_pca955x_match); 480 481 static int pca955x_probe(struct i2c_client *client) 482 { 483 struct pca955x *pca955x; 484 struct pca955x_led *pca955x_led; 485 struct pca955x_chipdef *chip; 486 struct led_classdev *led; 487 struct led_init_data init_data; 488 struct i2c_adapter *adapter; 489 int i, err; 490 struct pca955x_platform_data *pdata; 491 bool set_default_label = false; 492 bool keep_pwm = false; 493 char default_label[8]; 494 enum pca955x_type chip_type; 495 const void *md = device_get_match_data(&client->dev); 496 497 if (md) { 498 chip_type = (enum pca955x_type)md; 499 } else { 500 const struct i2c_device_id *id = i2c_match_id(pca955x_id, 501 client); 502 503 if (id) { 504 chip_type = (enum pca955x_type)id->driver_data; 505 } else { 506 dev_err(&client->dev, "unknown chip\n"); 507 return -ENODEV; 508 } 509 } 510 511 chip = &pca955x_chipdefs[chip_type]; 512 adapter = client->adapter; 513 pdata = dev_get_platdata(&client->dev); 514 if (!pdata) { 515 pdata = pca955x_get_pdata(client, chip); 516 if (IS_ERR(pdata)) 517 return PTR_ERR(pdata); 518 } 519 520 /* Make sure the slave address / chip type combo given is possible */ 521 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 522 chip->slv_addr) { 523 dev_err(&client->dev, "invalid slave address %02x\n", 524 client->addr); 525 return -ENODEV; 526 } 527 528 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 529 "slave address 0x%02x\n", client->name, chip->bits, 530 client->addr); 531 532 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 533 return -EIO; 534 535 if (pdata->num_leds != chip->bits) { 536 dev_err(&client->dev, 537 "board info claims %d LEDs on a %d-bit chip\n", 538 pdata->num_leds, chip->bits); 539 return -ENODEV; 540 } 541 542 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 543 if (!pca955x) 544 return -ENOMEM; 545 546 pca955x->leds = devm_kcalloc(&client->dev, chip->bits, 547 sizeof(*pca955x_led), GFP_KERNEL); 548 if (!pca955x->leds) 549 return -ENOMEM; 550 551 i2c_set_clientdata(client, pca955x); 552 553 mutex_init(&pca955x->lock); 554 pca955x->client = client; 555 pca955x->chipdef = chip; 556 557 init_data.devname_mandatory = false; 558 init_data.devicename = "pca955x"; 559 560 for (i = 0; i < chip->bits; i++) { 561 pca955x_led = &pca955x->leds[i]; 562 pca955x_led->led_num = i; 563 pca955x_led->pca955x = pca955x; 564 pca955x_led->type = pdata->leds[i].type; 565 566 switch (pca955x_led->type) { 567 case PCA955X_TYPE_NONE: 568 case PCA955X_TYPE_GPIO: 569 break; 570 case PCA955X_TYPE_LED: 571 led = &pca955x_led->led_cdev; 572 led->brightness_set_blocking = pca955x_led_set; 573 led->brightness_get = pca955x_led_get; 574 575 if (pdata->leds[i].default_state == 576 LEDS_GPIO_DEFSTATE_OFF) { 577 err = pca955x_led_set(led, LED_OFF); 578 if (err) 579 return err; 580 } else if (pdata->leds[i].default_state == 581 LEDS_GPIO_DEFSTATE_ON) { 582 err = pca955x_led_set(led, LED_FULL); 583 if (err) 584 return err; 585 } 586 587 init_data.fwnode = pdata->leds[i].fwnode; 588 589 if (is_of_node(init_data.fwnode)) { 590 if (to_of_node(init_data.fwnode)->name[0] == 591 '\0') 592 set_default_label = true; 593 else 594 set_default_label = false; 595 } else { 596 set_default_label = true; 597 } 598 599 if (set_default_label) { 600 snprintf(default_label, sizeof(default_label), 601 "%d", i); 602 init_data.default_label = default_label; 603 } else { 604 init_data.default_label = NULL; 605 } 606 607 err = devm_led_classdev_register_ext(&client->dev, led, 608 &init_data); 609 if (err) 610 return err; 611 612 set_bit(i, &pca955x->active_pins); 613 614 /* 615 * For default-state == "keep", let the core update the 616 * brightness from the hardware, then check the 617 * brightness to see if it's using PWM1. If so, PWM1 618 * should not be written below. 619 */ 620 if (pdata->leds[i].default_state == 621 LEDS_GPIO_DEFSTATE_KEEP) { 622 if (led->brightness != LED_FULL && 623 led->brightness != LED_OFF && 624 led->brightness != LED_HALF) 625 keep_pwm = true; 626 } 627 } 628 } 629 630 /* PWM0 is used for half brightness or 50% duty cycle */ 631 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 632 if (err) 633 return err; 634 635 if (!keep_pwm) { 636 /* PWM1 is used for variable brightness, default to OFF */ 637 err = pca955x_write_pwm(client, 1, 0); 638 if (err) 639 return err; 640 } 641 642 /* Set to fast frequency so we do not see flashing */ 643 err = pca955x_write_psc(client, 0, 0); 644 if (err) 645 return err; 646 err = pca955x_write_psc(client, 1, 0); 647 if (err) 648 return err; 649 650 #ifdef CONFIG_LEDS_PCA955X_GPIO 651 pca955x->gpio.label = "gpio-pca955x"; 652 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 653 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 654 pca955x->gpio.set = pca955x_gpio_set_value; 655 pca955x->gpio.get = pca955x_gpio_get_value; 656 pca955x->gpio.request = pca955x_gpio_request_pin; 657 pca955x->gpio.free = pca955x_gpio_free_pin; 658 pca955x->gpio.can_sleep = 1; 659 pca955x->gpio.base = -1; 660 pca955x->gpio.ngpio = chip->bits; 661 pca955x->gpio.parent = &client->dev; 662 pca955x->gpio.owner = THIS_MODULE; 663 664 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 665 pca955x); 666 if (err) { 667 /* Use data->gpio.dev as a flag for freeing gpiochip */ 668 pca955x->gpio.parent = NULL; 669 dev_warn(&client->dev, "could not add gpiochip\n"); 670 return err; 671 } 672 dev_info(&client->dev, "gpios %i...%i\n", 673 pca955x->gpio.base, pca955x->gpio.base + 674 pca955x->gpio.ngpio - 1); 675 #endif 676 677 return 0; 678 } 679 680 static struct i2c_driver pca955x_driver = { 681 .driver = { 682 .name = "leds-pca955x", 683 .of_match_table = of_pca955x_match, 684 }, 685 .probe_new = pca955x_probe, 686 .id_table = pca955x_id, 687 }; 688 689 module_i2c_driver(pca955x_driver); 690 691 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 692 MODULE_DESCRIPTION("PCA955x LED driver"); 693 MODULE_LICENSE("GPL v2"); 694