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 const 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 struct pca955x { 108 struct mutex lock; 109 struct pca955x_led *leds; 110 const struct pca955x_chipdef *chipdef; 111 struct i2c_client *client; 112 unsigned long active_pins; 113 #ifdef CONFIG_LEDS_PCA955X_GPIO 114 struct gpio_chip gpio; 115 #endif 116 }; 117 118 struct pca955x_led { 119 struct pca955x *pca955x; 120 struct led_classdev led_cdev; 121 int led_num; /* 0 .. 15 potentially */ 122 u32 type; 123 enum led_default_state default_state; 124 struct fwnode_handle *fwnode; 125 }; 126 127 struct pca955x_platform_data { 128 struct pca955x_led *leds; 129 int num_leds; 130 }; 131 132 /* 8 bits per input register */ 133 static inline int pca95xx_num_input_regs(int bits) 134 { 135 return (bits + 7) / 8; 136 } 137 138 /* 139 * Return an LED selector register value based on an existing one, with 140 * the appropriate 2-bit state value set for the given LED number (0-3). 141 */ 142 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) 143 { 144 return (oldval & (~(0x3 << (led_num << 1)))) | 145 ((state & 0x3) << (led_num << 1)); 146 } 147 148 /* 149 * Write to frequency prescaler register, used to program the 150 * period of the PWM output. period = (PSCx + 1) / 38 151 */ 152 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) 153 { 154 struct pca955x *pca955x = i2c_get_clientdata(client); 155 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n); 156 int ret; 157 158 ret = i2c_smbus_write_byte_data(client, cmd, val); 159 if (ret < 0) 160 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 161 __func__, n, val, ret); 162 return ret; 163 } 164 165 /* 166 * Write to PWM register, which determines the duty cycle of the 167 * output. LED is OFF when the count is less than the value of this 168 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 169 * 170 * Duty cycle is (256 - PWMx) / 256 171 */ 172 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 173 { 174 struct pca955x *pca955x = i2c_get_clientdata(client); 175 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 176 int ret; 177 178 ret = i2c_smbus_write_byte_data(client, cmd, val); 179 if (ret < 0) 180 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 181 __func__, n, val, ret); 182 return ret; 183 } 184 185 /* 186 * Write to LED selector register, which determines the source that 187 * drives the LED output. 188 */ 189 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 190 { 191 struct pca955x *pca955x = i2c_get_clientdata(client); 192 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 193 int ret; 194 195 ret = i2c_smbus_write_byte_data(client, cmd, val); 196 if (ret < 0) 197 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 198 __func__, n, val, ret); 199 return ret; 200 } 201 202 /* 203 * Read the LED selector register, which determines the source that 204 * drives the LED output. 205 */ 206 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) 207 { 208 struct pca955x *pca955x = i2c_get_clientdata(client); 209 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; 210 int ret; 211 212 ret = i2c_smbus_read_byte_data(client, cmd); 213 if (ret < 0) { 214 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 215 __func__, n, ret); 216 return ret; 217 } 218 *val = (u8)ret; 219 return 0; 220 } 221 222 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val) 223 { 224 struct pca955x *pca955x = i2c_get_clientdata(client); 225 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); 226 int ret; 227 228 ret = i2c_smbus_read_byte_data(client, cmd); 229 if (ret < 0) { 230 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 231 __func__, n, ret); 232 return ret; 233 } 234 *val = (u8)ret; 235 return 0; 236 } 237 238 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev) 239 { 240 struct pca955x_led *pca955x_led = container_of(led_cdev, 241 struct pca955x_led, 242 led_cdev); 243 struct pca955x *pca955x = pca955x_led->pca955x; 244 u8 ls, pwm; 245 int ret; 246 247 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls); 248 if (ret) 249 return ret; 250 251 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3; 252 switch (ls) { 253 case PCA955X_LS_LED_ON: 254 ret = LED_FULL; 255 break; 256 case PCA955X_LS_LED_OFF: 257 ret = LED_OFF; 258 break; 259 case PCA955X_LS_BLINK0: 260 ret = LED_HALF; 261 break; 262 case PCA955X_LS_BLINK1: 263 ret = pca955x_read_pwm(pca955x->client, 1, &pwm); 264 if (ret) 265 return ret; 266 ret = 255 - pwm; 267 break; 268 } 269 270 return ret; 271 } 272 273 static int pca955x_led_set(struct led_classdev *led_cdev, 274 enum led_brightness value) 275 { 276 struct pca955x_led *pca955x_led; 277 struct pca955x *pca955x; 278 u8 ls; 279 int chip_ls; /* which LSx to use (0-3 potentially) */ 280 int ls_led; /* which set of bits within LSx to use (0-3) */ 281 int ret; 282 283 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 284 pca955x = pca955x_led->pca955x; 285 286 chip_ls = pca955x_led->led_num / 4; 287 ls_led = pca955x_led->led_num % 4; 288 289 mutex_lock(&pca955x->lock); 290 291 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 292 if (ret) 293 goto out; 294 295 switch (value) { 296 case LED_FULL: 297 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 298 break; 299 case LED_OFF: 300 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 301 break; 302 case LED_HALF: 303 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 304 break; 305 default: 306 /* 307 * Use PWM1 for all other values. This has the unwanted 308 * side effect of making all LEDs on the chip share the 309 * same brightness level if set to a value other than 310 * OFF, HALF, or FULL. But, this is probably better than 311 * just turning off for all other values. 312 */ 313 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 314 if (ret) 315 goto out; 316 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 317 break; 318 } 319 320 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 321 322 out: 323 mutex_unlock(&pca955x->lock); 324 325 return ret; 326 } 327 328 #ifdef CONFIG_LEDS_PCA955X_GPIO 329 /* 330 * Read the INPUT register, which contains the state of LEDs. 331 */ 332 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 333 { 334 int ret = i2c_smbus_read_byte_data(client, n); 335 336 if (ret < 0) { 337 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 338 __func__, n, ret); 339 return ret; 340 } 341 *val = (u8)ret; 342 return 0; 343 344 } 345 346 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 347 { 348 struct pca955x *pca955x = gpiochip_get_data(gc); 349 350 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0; 351 } 352 353 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset) 354 { 355 struct pca955x *pca955x = gpiochip_get_data(gc); 356 357 clear_bit(offset, &pca955x->active_pins); 358 } 359 360 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 361 int val) 362 { 363 struct pca955x *pca955x = gpiochip_get_data(gc); 364 struct pca955x_led *led = &pca955x->leds[offset]; 365 366 if (val) 367 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 368 369 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 370 } 371 372 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 373 int val) 374 { 375 pca955x_set_value(gc, offset, val); 376 } 377 378 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 379 { 380 struct pca955x *pca955x = gpiochip_get_data(gc); 381 struct pca955x_led *led = &pca955x->leds[offset]; 382 u8 reg = 0; 383 384 /* There is nothing we can do about errors */ 385 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 386 387 return !!(reg & (1 << (led->led_num % 8))); 388 } 389 390 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 391 unsigned int offset) 392 { 393 struct pca955x *pca955x = gpiochip_get_data(gc); 394 struct pca955x_led *led = &pca955x->leds[offset]; 395 396 /* To use as input ensure pin is not driven. */ 397 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 398 } 399 400 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 401 unsigned int offset, int val) 402 { 403 return pca955x_set_value(gc, offset, val); 404 } 405 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 406 407 static struct pca955x_platform_data * 408 pca955x_get_pdata(struct i2c_client *client, const struct pca955x_chipdef *chip) 409 { 410 struct pca955x_platform_data *pdata; 411 struct pca955x_led *led; 412 struct fwnode_handle *child; 413 int count; 414 415 count = device_get_child_node_count(&client->dev); 416 if (count > chip->bits) 417 return ERR_PTR(-ENODEV); 418 419 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 420 if (!pdata) 421 return ERR_PTR(-ENOMEM); 422 423 pdata->leds = devm_kcalloc(&client->dev, 424 chip->bits, sizeof(struct pca955x_led), 425 GFP_KERNEL); 426 if (!pdata->leds) 427 return ERR_PTR(-ENOMEM); 428 429 device_for_each_child_node(&client->dev, child) { 430 u32 reg; 431 int res; 432 433 res = fwnode_property_read_u32(child, "reg", ®); 434 if ((res != 0) || (reg >= chip->bits)) 435 continue; 436 437 led = &pdata->leds[reg]; 438 led->type = PCA955X_TYPE_LED; 439 led->fwnode = child; 440 led->default_state = led_init_default_state_get(child); 441 442 fwnode_property_read_u32(child, "type", &led->type); 443 } 444 445 pdata->num_leds = chip->bits; 446 447 return pdata; 448 } 449 450 static int pca955x_probe(struct i2c_client *client) 451 { 452 struct pca955x *pca955x; 453 struct pca955x_led *pca955x_led; 454 const struct pca955x_chipdef *chip; 455 struct led_classdev *led; 456 struct led_init_data init_data; 457 struct i2c_adapter *adapter; 458 int i, err; 459 struct pca955x_platform_data *pdata; 460 bool set_default_label = false; 461 bool keep_pwm = false; 462 char default_label[8]; 463 464 chip = i2c_get_match_data(client); 465 if (!chip) 466 return dev_err_probe(&client->dev, -ENODEV, "unknown chip\n"); 467 468 adapter = client->adapter; 469 pdata = dev_get_platdata(&client->dev); 470 if (!pdata) { 471 pdata = pca955x_get_pdata(client, chip); 472 if (IS_ERR(pdata)) 473 return PTR_ERR(pdata); 474 } 475 476 /* Make sure the slave address / chip type combo given is possible */ 477 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 478 chip->slv_addr) { 479 dev_err(&client->dev, "invalid slave address %02x\n", 480 client->addr); 481 return -ENODEV; 482 } 483 484 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 485 "slave address 0x%02x\n", client->name, chip->bits, 486 client->addr); 487 488 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 489 return -EIO; 490 491 if (pdata->num_leds != chip->bits) { 492 dev_err(&client->dev, 493 "board info claims %d LEDs on a %d-bit chip\n", 494 pdata->num_leds, chip->bits); 495 return -ENODEV; 496 } 497 498 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 499 if (!pca955x) 500 return -ENOMEM; 501 502 pca955x->leds = devm_kcalloc(&client->dev, chip->bits, 503 sizeof(*pca955x_led), GFP_KERNEL); 504 if (!pca955x->leds) 505 return -ENOMEM; 506 507 i2c_set_clientdata(client, pca955x); 508 509 mutex_init(&pca955x->lock); 510 pca955x->client = client; 511 pca955x->chipdef = chip; 512 513 init_data.devname_mandatory = false; 514 init_data.devicename = "pca955x"; 515 516 for (i = 0; i < chip->bits; i++) { 517 pca955x_led = &pca955x->leds[i]; 518 pca955x_led->led_num = i; 519 pca955x_led->pca955x = pca955x; 520 pca955x_led->type = pdata->leds[i].type; 521 522 switch (pca955x_led->type) { 523 case PCA955X_TYPE_NONE: 524 case PCA955X_TYPE_GPIO: 525 break; 526 case PCA955X_TYPE_LED: 527 led = &pca955x_led->led_cdev; 528 led->brightness_set_blocking = pca955x_led_set; 529 led->brightness_get = pca955x_led_get; 530 531 if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) { 532 err = pca955x_led_set(led, LED_OFF); 533 if (err) 534 return err; 535 } else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) { 536 err = pca955x_led_set(led, LED_FULL); 537 if (err) 538 return err; 539 } 540 541 init_data.fwnode = pdata->leds[i].fwnode; 542 543 if (is_of_node(init_data.fwnode)) { 544 if (to_of_node(init_data.fwnode)->name[0] == 545 '\0') 546 set_default_label = true; 547 else 548 set_default_label = false; 549 } else { 550 set_default_label = true; 551 } 552 553 if (set_default_label) { 554 snprintf(default_label, sizeof(default_label), 555 "%d", i); 556 init_data.default_label = default_label; 557 } else { 558 init_data.default_label = NULL; 559 } 560 561 err = devm_led_classdev_register_ext(&client->dev, led, 562 &init_data); 563 if (err) 564 return err; 565 566 set_bit(i, &pca955x->active_pins); 567 568 /* 569 * For default-state == "keep", let the core update the 570 * brightness from the hardware, then check the 571 * brightness to see if it's using PWM1. If so, PWM1 572 * should not be written below. 573 */ 574 if (pdata->leds[i].default_state == LEDS_DEFSTATE_KEEP) { 575 if (led->brightness != LED_FULL && 576 led->brightness != LED_OFF && 577 led->brightness != LED_HALF) 578 keep_pwm = true; 579 } 580 } 581 } 582 583 /* PWM0 is used for half brightness or 50% duty cycle */ 584 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 585 if (err) 586 return err; 587 588 if (!keep_pwm) { 589 /* PWM1 is used for variable brightness, default to OFF */ 590 err = pca955x_write_pwm(client, 1, 0); 591 if (err) 592 return err; 593 } 594 595 /* Set to fast frequency so we do not see flashing */ 596 err = pca955x_write_psc(client, 0, 0); 597 if (err) 598 return err; 599 err = pca955x_write_psc(client, 1, 0); 600 if (err) 601 return err; 602 603 #ifdef CONFIG_LEDS_PCA955X_GPIO 604 pca955x->gpio.label = "gpio-pca955x"; 605 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 606 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 607 pca955x->gpio.set = pca955x_gpio_set_value; 608 pca955x->gpio.get = pca955x_gpio_get_value; 609 pca955x->gpio.request = pca955x_gpio_request_pin; 610 pca955x->gpio.free = pca955x_gpio_free_pin; 611 pca955x->gpio.can_sleep = 1; 612 pca955x->gpio.base = -1; 613 pca955x->gpio.ngpio = chip->bits; 614 pca955x->gpio.parent = &client->dev; 615 pca955x->gpio.owner = THIS_MODULE; 616 617 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 618 pca955x); 619 if (err) { 620 /* Use data->gpio.dev as a flag for freeing gpiochip */ 621 pca955x->gpio.parent = NULL; 622 dev_warn(&client->dev, "could not add gpiochip\n"); 623 return err; 624 } 625 dev_info(&client->dev, "gpios %i...%i\n", 626 pca955x->gpio.base, pca955x->gpio.base + 627 pca955x->gpio.ngpio - 1); 628 #endif 629 630 return 0; 631 } 632 633 static const struct i2c_device_id pca955x_id[] = { 634 { "pca9550", (kernel_ulong_t)&pca955x_chipdefs[pca9550] }, 635 { "pca9551", (kernel_ulong_t)&pca955x_chipdefs[pca9551] }, 636 { "pca9552", (kernel_ulong_t)&pca955x_chipdefs[pca9552] }, 637 { "ibm-pca9552", (kernel_ulong_t)&pca955x_chipdefs[ibm_pca9552] }, 638 { "pca9553", (kernel_ulong_t)&pca955x_chipdefs[pca9553] }, 639 {} 640 }; 641 MODULE_DEVICE_TABLE(i2c, pca955x_id); 642 643 static const struct of_device_id of_pca955x_match[] = { 644 { .compatible = "nxp,pca9550", .data = &pca955x_chipdefs[pca9550] }, 645 { .compatible = "nxp,pca9551", .data = &pca955x_chipdefs[pca9551] }, 646 { .compatible = "nxp,pca9552", .data = &pca955x_chipdefs[pca9552] }, 647 { .compatible = "ibm,pca9552", .data = &pca955x_chipdefs[ibm_pca9552] }, 648 { .compatible = "nxp,pca9553", .data = &pca955x_chipdefs[pca9553] }, 649 {} 650 }; 651 MODULE_DEVICE_TABLE(of, of_pca955x_match); 652 653 static struct i2c_driver pca955x_driver = { 654 .driver = { 655 .name = "leds-pca955x", 656 .of_match_table = of_pca955x_match, 657 }, 658 .probe = pca955x_probe, 659 .id_table = pca955x_id, 660 }; 661 662 module_i2c_driver(pca955x_driver); 663 664 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 665 MODULE_DESCRIPTION("PCA955x LED driver"); 666 MODULE_LICENSE("GPL v2"); 667