1 /* 2 * Copyright 2007-2008 Extreme Engineering Solutions, Inc. 3 * 4 * Author: Nate Case <ncase@xes-inc.com> 5 * 6 * This file is subject to the terms and conditions of version 2 of 7 * the GNU General Public License. See the file COPYING in the main 8 * directory of this archive for more details. 9 * 10 * LED driver for various PCA955x I2C LED drivers 11 * 12 * Supported devices: 13 * 14 * Device Description 7-bit slave address 15 * ------ ----------- ------------------- 16 * PCA9550 2-bit driver 0x60 .. 0x61 17 * PCA9551 8-bit driver 0x60 .. 0x67 18 * PCA9552 16-bit driver 0x60 .. 0x67 19 * PCA9553/01 4-bit driver 0x62 20 * PCA9553/02 4-bit driver 0x63 21 * 22 * Philips PCA955x LED driver chips follow a register map as shown below: 23 * 24 * Control Register Description 25 * ---------------- ----------- 26 * 0x0 Input register 0 27 * .. 28 * NUM_INPUT_REGS - 1 Last Input register X 29 * 30 * NUM_INPUT_REGS Frequency prescaler 0 31 * NUM_INPUT_REGS + 1 PWM register 0 32 * NUM_INPUT_REGS + 2 Frequency prescaler 1 33 * NUM_INPUT_REGS + 3 PWM register 1 34 * 35 * NUM_INPUT_REGS + 4 LED selector 0 36 * NUM_INPUT_REGS + 4 37 * + NUM_LED_REGS - 1 Last LED selector 38 * 39 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many 40 * bits the chip supports. 41 */ 42 43 #include <linux/acpi.h> 44 #include <linux/ctype.h> 45 #include <linux/delay.h> 46 #include <linux/err.h> 47 #include <linux/gpio.h> 48 #include <linux/i2c.h> 49 #include <linux/leds.h> 50 #include <linux/module.h> 51 #include <linux/of_device.h> 52 #include <linux/of.h> 53 #include <linux/slab.h> 54 #include <linux/string.h> 55 56 #include <dt-bindings/leds/leds-pca955x.h> 57 58 /* LED select registers determine the source that drives LED outputs */ 59 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ 60 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ 61 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ 62 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ 63 64 #define PCA955X_GPIO_INPUT LED_OFF 65 #define PCA955X_GPIO_HIGH LED_OFF 66 #define PCA955X_GPIO_LOW LED_FULL 67 68 enum pca955x_type { 69 pca9550, 70 pca9551, 71 pca9552, 72 pca9553, 73 }; 74 75 struct pca955x_chipdef { 76 int bits; 77 u8 slv_addr; /* 7-bit slave address mask */ 78 int slv_addr_shift; /* Number of bits to ignore */ 79 }; 80 81 static struct pca955x_chipdef pca955x_chipdefs[] = { 82 [pca9550] = { 83 .bits = 2, 84 .slv_addr = /* 110000x */ 0x60, 85 .slv_addr_shift = 1, 86 }, 87 [pca9551] = { 88 .bits = 8, 89 .slv_addr = /* 1100xxx */ 0x60, 90 .slv_addr_shift = 3, 91 }, 92 [pca9552] = { 93 .bits = 16, 94 .slv_addr = /* 1100xxx */ 0x60, 95 .slv_addr_shift = 3, 96 }, 97 [pca9553] = { 98 .bits = 4, 99 .slv_addr = /* 110001x */ 0x62, 100 .slv_addr_shift = 1, 101 }, 102 }; 103 104 static const struct i2c_device_id pca955x_id[] = { 105 { "pca9550", pca9550 }, 106 { "pca9551", pca9551 }, 107 { "pca9552", pca9552 }, 108 { "pca9553", pca9553 }, 109 { } 110 }; 111 MODULE_DEVICE_TABLE(i2c, pca955x_id); 112 113 static const struct acpi_device_id pca955x_acpi_ids[] = { 114 { "PCA9550", pca9550 }, 115 { "PCA9551", pca9551 }, 116 { "PCA9552", pca9552 }, 117 { "PCA9553", pca9553 }, 118 { } 119 }; 120 MODULE_DEVICE_TABLE(acpi, pca955x_acpi_ids); 121 122 struct pca955x { 123 struct mutex lock; 124 struct pca955x_led *leds; 125 struct pca955x_chipdef *chipdef; 126 struct i2c_client *client; 127 #ifdef CONFIG_LEDS_PCA955X_GPIO 128 struct gpio_chip gpio; 129 #endif 130 }; 131 132 struct pca955x_led { 133 struct pca955x *pca955x; 134 struct led_classdev led_cdev; 135 int led_num; /* 0 .. 15 potentially */ 136 char name[32]; 137 u32 type; 138 const char *default_trigger; 139 }; 140 141 struct pca955x_platform_data { 142 struct pca955x_led *leds; 143 int num_leds; 144 }; 145 146 /* 8 bits per input register */ 147 static inline int pca95xx_num_input_regs(int bits) 148 { 149 return (bits + 7) / 8; 150 } 151 152 /* 4 bits per LED selector register */ 153 static inline int pca95xx_num_led_regs(int bits) 154 { 155 return (bits + 3) / 4; 156 } 157 158 /* 159 * Return an LED selector register value based on an existing one, with 160 * the appropriate 2-bit state value set for the given LED number (0-3). 161 */ 162 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) 163 { 164 return (oldval & (~(0x3 << (led_num << 1)))) | 165 ((state & 0x3) << (led_num << 1)); 166 } 167 168 /* 169 * Write to frequency prescaler register, used to program the 170 * period of the PWM output. period = (PSCx + 1) / 38 171 */ 172 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) 173 { 174 struct pca955x *pca955x = i2c_get_clientdata(client); 175 int ret; 176 177 ret = i2c_smbus_write_byte_data(client, 178 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, 179 val); 180 if (ret < 0) 181 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 182 __func__, n, val, ret); 183 return ret; 184 } 185 186 /* 187 * Write to PWM register, which determines the duty cycle of the 188 * output. LED is OFF when the count is less than the value of this 189 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 190 * 191 * Duty cycle is (256 - PWMx) / 256 192 */ 193 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 194 { 195 struct pca955x *pca955x = i2c_get_clientdata(client); 196 int ret; 197 198 ret = i2c_smbus_write_byte_data(client, 199 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, 200 val); 201 if (ret < 0) 202 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 203 __func__, n, val, ret); 204 return ret; 205 } 206 207 /* 208 * Write to LED selector register, which determines the source that 209 * drives the LED output. 210 */ 211 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 212 { 213 struct pca955x *pca955x = i2c_get_clientdata(client); 214 int ret; 215 216 ret = i2c_smbus_write_byte_data(client, 217 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, 218 val); 219 if (ret < 0) 220 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 221 __func__, n, val, ret); 222 return ret; 223 } 224 225 /* 226 * Read the LED selector register, which determines the source that 227 * drives the LED output. 228 */ 229 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) 230 { 231 struct pca955x *pca955x = i2c_get_clientdata(client); 232 int ret; 233 234 ret = i2c_smbus_read_byte_data(client, 235 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); 236 if (ret < 0) { 237 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 238 __func__, n, ret); 239 return ret; 240 } 241 *val = (u8)ret; 242 return 0; 243 } 244 245 static int pca955x_led_set(struct led_classdev *led_cdev, 246 enum led_brightness value) 247 { 248 struct pca955x_led *pca955x_led; 249 struct pca955x *pca955x; 250 u8 ls; 251 int chip_ls; /* which LSx to use (0-3 potentially) */ 252 int ls_led; /* which set of bits within LSx to use (0-3) */ 253 int ret; 254 255 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 256 pca955x = pca955x_led->pca955x; 257 258 chip_ls = pca955x_led->led_num / 4; 259 ls_led = pca955x_led->led_num % 4; 260 261 mutex_lock(&pca955x->lock); 262 263 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 264 if (ret) 265 goto out; 266 267 switch (value) { 268 case LED_FULL: 269 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 270 break; 271 case LED_OFF: 272 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 273 break; 274 case LED_HALF: 275 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 276 break; 277 default: 278 /* 279 * Use PWM1 for all other values. This has the unwanted 280 * side effect of making all LEDs on the chip share the 281 * same brightness level if set to a value other than 282 * OFF, HALF, or FULL. But, this is probably better than 283 * just turning off for all other values. 284 */ 285 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 286 if (ret) 287 goto out; 288 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 289 break; 290 } 291 292 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 293 294 out: 295 mutex_unlock(&pca955x->lock); 296 297 return ret; 298 } 299 300 #ifdef CONFIG_LEDS_PCA955X_GPIO 301 /* 302 * Read the INPUT register, which contains the state of LEDs. 303 */ 304 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 305 { 306 int ret = i2c_smbus_read_byte_data(client, n); 307 308 if (ret < 0) { 309 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 310 __func__, n, ret); 311 return ret; 312 } 313 *val = (u8)ret; 314 return 0; 315 316 } 317 318 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 319 { 320 struct pca955x *pca955x = gpiochip_get_data(gc); 321 struct pca955x_led *led = &pca955x->leds[offset]; 322 323 if (led->type == PCA955X_TYPE_GPIO) 324 return 0; 325 326 return -EBUSY; 327 } 328 329 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 330 int val) 331 { 332 struct pca955x *pca955x = gpiochip_get_data(gc); 333 struct pca955x_led *led = &pca955x->leds[offset]; 334 335 if (val) 336 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 337 338 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 339 } 340 341 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 342 int val) 343 { 344 pca955x_set_value(gc, offset, val); 345 } 346 347 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 348 { 349 struct pca955x *pca955x = gpiochip_get_data(gc); 350 struct pca955x_led *led = &pca955x->leds[offset]; 351 u8 reg = 0; 352 353 /* There is nothing we can do about errors */ 354 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 355 356 return !!(reg & (1 << (led->led_num % 8))); 357 } 358 359 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 360 unsigned int offset) 361 { 362 struct pca955x *pca955x = gpiochip_get_data(gc); 363 struct pca955x_led *led = &pca955x->leds[offset]; 364 365 /* To use as input ensure pin is not driven. */ 366 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 367 } 368 369 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 370 unsigned int offset, int val) 371 { 372 return pca955x_set_value(gc, offset, val); 373 } 374 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 375 376 #if IS_ENABLED(CONFIG_OF) 377 static struct pca955x_platform_data * 378 pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip) 379 { 380 struct device_node *np = client->dev.of_node; 381 struct device_node *child; 382 struct pca955x_platform_data *pdata; 383 int count; 384 385 count = of_get_child_count(np); 386 if (!count || count > chip->bits) 387 return ERR_PTR(-ENODEV); 388 389 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 390 if (!pdata) 391 return ERR_PTR(-ENOMEM); 392 393 pdata->leds = devm_kzalloc(&client->dev, 394 sizeof(struct pca955x_led) * chip->bits, 395 GFP_KERNEL); 396 if (!pdata->leds) 397 return ERR_PTR(-ENOMEM); 398 399 for_each_child_of_node(np, child) { 400 const char *name; 401 u32 reg; 402 int res; 403 404 res = of_property_read_u32(child, "reg", ®); 405 if ((res != 0) || (reg >= chip->bits)) 406 continue; 407 408 if (of_property_read_string(child, "label", &name)) 409 name = child->name; 410 411 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name), 412 "%s", name); 413 414 pdata->leds[reg].type = PCA955X_TYPE_LED; 415 of_property_read_u32(child, "type", &pdata->leds[reg].type); 416 of_property_read_string(child, "linux,default-trigger", 417 &pdata->leds[reg].default_trigger); 418 } 419 420 pdata->num_leds = chip->bits; 421 422 return pdata; 423 } 424 425 static const struct of_device_id of_pca955x_match[] = { 426 { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, 427 { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, 428 { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, 429 { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, 430 {}, 431 }; 432 433 MODULE_DEVICE_TABLE(of, of_pca955x_match); 434 #else 435 static struct pca955x_platform_data * 436 pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip) 437 { 438 return ERR_PTR(-ENODEV); 439 } 440 #endif 441 442 static int pca955x_probe(struct i2c_client *client, 443 const struct i2c_device_id *id) 444 { 445 struct pca955x *pca955x; 446 struct pca955x_led *pca955x_led; 447 struct pca955x_chipdef *chip; 448 struct i2c_adapter *adapter; 449 int i, err; 450 struct pca955x_platform_data *pdata; 451 int ngpios = 0; 452 453 if (id) { 454 chip = &pca955x_chipdefs[id->driver_data]; 455 } else { 456 const struct acpi_device_id *acpi_id; 457 458 acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev); 459 if (!acpi_id) 460 return -ENODEV; 461 chip = &pca955x_chipdefs[acpi_id->driver_data]; 462 } 463 adapter = to_i2c_adapter(client->dev.parent); 464 pdata = dev_get_platdata(&client->dev); 465 if (!pdata) { 466 pdata = pca955x_pdata_of_init(client, chip); 467 if (IS_ERR(pdata)) 468 return PTR_ERR(pdata); 469 } 470 471 /* Make sure the slave address / chip type combo given is possible */ 472 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 473 chip->slv_addr) { 474 dev_err(&client->dev, "invalid slave address %02x\n", 475 client->addr); 476 return -ENODEV; 477 } 478 479 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 480 "slave address 0x%02x\n", 481 client->name, chip->bits, client->addr); 482 483 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 484 return -EIO; 485 486 if (pdata->num_leds != chip->bits) { 487 dev_err(&client->dev, 488 "board info claims %d LEDs on a %d-bit chip\n", 489 pdata->num_leds, chip->bits); 490 return -ENODEV; 491 } 492 493 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 494 if (!pca955x) 495 return -ENOMEM; 496 497 pca955x->leds = devm_kzalloc(&client->dev, 498 sizeof(*pca955x_led) * chip->bits, GFP_KERNEL); 499 if (!pca955x->leds) 500 return -ENOMEM; 501 502 i2c_set_clientdata(client, pca955x); 503 504 mutex_init(&pca955x->lock); 505 pca955x->client = client; 506 pca955x->chipdef = chip; 507 508 for (i = 0; i < chip->bits; i++) { 509 pca955x_led = &pca955x->leds[i]; 510 pca955x_led->led_num = i; 511 pca955x_led->pca955x = pca955x; 512 pca955x_led->type = pdata->leds[i].type; 513 514 switch (pca955x_led->type) { 515 case PCA955X_TYPE_NONE: 516 break; 517 case PCA955X_TYPE_GPIO: 518 ngpios++; 519 break; 520 case PCA955X_TYPE_LED: 521 /* 522 * Platform data can specify LED names and 523 * default triggers 524 */ 525 if (pdata->leds[i].name[0] == '\0') 526 snprintf(pdata->leds[i].name, 527 sizeof(pdata->leds[i].name), "%d", i); 528 529 snprintf(pca955x_led->name, 530 sizeof(pca955x_led->name), "pca955x:%s", 531 pdata->leds[i].name); 532 533 if (pdata->leds[i].default_trigger) 534 pca955x_led->led_cdev.default_trigger = 535 pdata->leds[i].default_trigger; 536 537 pca955x_led->led_cdev.name = pca955x_led->name; 538 pca955x_led->led_cdev.brightness_set_blocking = 539 pca955x_led_set; 540 541 err = devm_led_classdev_register(&client->dev, 542 &pca955x_led->led_cdev); 543 if (err) 544 return err; 545 546 /* Turn off LED */ 547 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF); 548 if (err) 549 return err; 550 } 551 } 552 553 /* PWM0 is used for half brightness or 50% duty cycle */ 554 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 555 if (err) 556 return err; 557 558 /* PWM1 is used for variable brightness, default to OFF */ 559 err = pca955x_write_pwm(client, 1, 0); 560 if (err) 561 return err; 562 563 /* Set to fast frequency so we do not see flashing */ 564 err = pca955x_write_psc(client, 0, 0); 565 if (err) 566 return err; 567 err = pca955x_write_psc(client, 1, 0); 568 if (err) 569 return err; 570 571 #ifdef CONFIG_LEDS_PCA955X_GPIO 572 if (ngpios) { 573 pca955x->gpio.label = "gpio-pca955x"; 574 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 575 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 576 pca955x->gpio.set = pca955x_gpio_set_value; 577 pca955x->gpio.get = pca955x_gpio_get_value; 578 pca955x->gpio.request = pca955x_gpio_request_pin; 579 pca955x->gpio.can_sleep = 1; 580 pca955x->gpio.base = -1; 581 pca955x->gpio.ngpio = ngpios; 582 pca955x->gpio.parent = &client->dev; 583 pca955x->gpio.owner = THIS_MODULE; 584 585 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 586 pca955x); 587 if (err) { 588 /* Use data->gpio.dev as a flag for freeing gpiochip */ 589 pca955x->gpio.parent = NULL; 590 dev_warn(&client->dev, "could not add gpiochip\n"); 591 return err; 592 } 593 dev_info(&client->dev, "gpios %i...%i\n", 594 pca955x->gpio.base, pca955x->gpio.base + 595 pca955x->gpio.ngpio - 1); 596 } 597 #endif 598 599 return 0; 600 } 601 602 static struct i2c_driver pca955x_driver = { 603 .driver = { 604 .name = "leds-pca955x", 605 .acpi_match_table = ACPI_PTR(pca955x_acpi_ids), 606 .of_match_table = of_match_ptr(of_pca955x_match), 607 }, 608 .probe = pca955x_probe, 609 .id_table = pca955x_id, 610 }; 611 612 module_i2c_driver(pca955x_driver); 613 614 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 615 MODULE_DESCRIPTION("PCA955x LED driver"); 616 MODULE_LICENSE("GPL v2"); 617