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 char name[32]; 131 u32 type; 132 const char *default_trigger; 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 int ret; 170 171 ret = i2c_smbus_write_byte_data(client, 172 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, 173 val); 174 if (ret < 0) 175 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 176 __func__, n, val, ret); 177 return ret; 178 } 179 180 /* 181 * Write to PWM register, which determines the duty cycle of the 182 * output. LED is OFF when the count is less than the value of this 183 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 184 * 185 * Duty cycle is (256 - PWMx) / 256 186 */ 187 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 188 { 189 struct pca955x *pca955x = i2c_get_clientdata(client); 190 int ret; 191 192 ret = i2c_smbus_write_byte_data(client, 193 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, 194 val); 195 if (ret < 0) 196 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 197 __func__, n, val, ret); 198 return ret; 199 } 200 201 /* 202 * Write to LED selector register, which determines the source that 203 * drives the LED output. 204 */ 205 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 206 { 207 struct pca955x *pca955x = i2c_get_clientdata(client); 208 int ret; 209 210 ret = i2c_smbus_write_byte_data(client, 211 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, 212 val); 213 if (ret < 0) 214 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 215 __func__, n, val, ret); 216 return ret; 217 } 218 219 /* 220 * Read the LED selector register, which determines the source that 221 * drives the LED output. 222 */ 223 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) 224 { 225 struct pca955x *pca955x = i2c_get_clientdata(client); 226 int ret; 227 228 ret = i2c_smbus_read_byte_data(client, 229 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); 230 if (ret < 0) { 231 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 232 __func__, n, ret); 233 return ret; 234 } 235 *val = (u8)ret; 236 return 0; 237 } 238 239 static int pca955x_led_set(struct led_classdev *led_cdev, 240 enum led_brightness value) 241 { 242 struct pca955x_led *pca955x_led; 243 struct pca955x *pca955x; 244 u8 ls; 245 int chip_ls; /* which LSx to use (0-3 potentially) */ 246 int ls_led; /* which set of bits within LSx to use (0-3) */ 247 int ret; 248 249 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 250 pca955x = pca955x_led->pca955x; 251 252 chip_ls = pca955x_led->led_num / 4; 253 ls_led = pca955x_led->led_num % 4; 254 255 mutex_lock(&pca955x->lock); 256 257 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 258 if (ret) 259 goto out; 260 261 switch (value) { 262 case LED_FULL: 263 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 264 break; 265 case LED_OFF: 266 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 267 break; 268 case LED_HALF: 269 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 270 break; 271 default: 272 /* 273 * Use PWM1 for all other values. This has the unwanted 274 * side effect of making all LEDs on the chip share the 275 * same brightness level if set to a value other than 276 * OFF, HALF, or FULL. But, this is probably better than 277 * just turning off for all other values. 278 */ 279 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 280 if (ret) 281 goto out; 282 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 283 break; 284 } 285 286 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 287 288 out: 289 mutex_unlock(&pca955x->lock); 290 291 return ret; 292 } 293 294 #ifdef CONFIG_LEDS_PCA955X_GPIO 295 /* 296 * Read the INPUT register, which contains the state of LEDs. 297 */ 298 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 299 { 300 int ret = i2c_smbus_read_byte_data(client, n); 301 302 if (ret < 0) { 303 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 304 __func__, n, ret); 305 return ret; 306 } 307 *val = (u8)ret; 308 return 0; 309 310 } 311 312 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 313 { 314 struct pca955x *pca955x = gpiochip_get_data(gc); 315 struct pca955x_led *led = &pca955x->leds[offset]; 316 317 if (led->type == PCA955X_TYPE_GPIO) 318 return 0; 319 320 return -EBUSY; 321 } 322 323 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 324 int val) 325 { 326 struct pca955x *pca955x = gpiochip_get_data(gc); 327 struct pca955x_led *led = &pca955x->leds[offset]; 328 329 if (val) 330 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 331 332 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 333 } 334 335 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 336 int val) 337 { 338 pca955x_set_value(gc, offset, val); 339 } 340 341 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 342 { 343 struct pca955x *pca955x = gpiochip_get_data(gc); 344 struct pca955x_led *led = &pca955x->leds[offset]; 345 u8 reg = 0; 346 347 /* There is nothing we can do about errors */ 348 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 349 350 return !!(reg & (1 << (led->led_num % 8))); 351 } 352 353 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 354 unsigned int offset) 355 { 356 struct pca955x *pca955x = gpiochip_get_data(gc); 357 struct pca955x_led *led = &pca955x->leds[offset]; 358 359 /* To use as input ensure pin is not driven. */ 360 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 361 } 362 363 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 364 unsigned int offset, int val) 365 { 366 return pca955x_set_value(gc, offset, val); 367 } 368 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 369 370 static struct pca955x_platform_data * 371 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) 372 { 373 struct pca955x_platform_data *pdata; 374 struct fwnode_handle *child; 375 int count; 376 377 count = device_get_child_node_count(&client->dev); 378 if (!count || count > chip->bits) 379 return ERR_PTR(-ENODEV); 380 381 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 382 if (!pdata) 383 return ERR_PTR(-ENOMEM); 384 385 pdata->leds = devm_kcalloc(&client->dev, 386 chip->bits, sizeof(struct pca955x_led), 387 GFP_KERNEL); 388 if (!pdata->leds) 389 return ERR_PTR(-ENOMEM); 390 391 device_for_each_child_node(&client->dev, child) { 392 const char *name; 393 u32 reg; 394 int res; 395 396 res = fwnode_property_read_u32(child, "reg", ®); 397 if ((res != 0) || (reg >= chip->bits)) 398 continue; 399 400 res = fwnode_property_read_string(child, "label", &name); 401 if ((res != 0) && is_of_node(child)) 402 name = to_of_node(child)->name; 403 404 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name), 405 "%s", name); 406 407 pdata->leds[reg].type = PCA955X_TYPE_LED; 408 fwnode_property_read_u32(child, "type", &pdata->leds[reg].type); 409 fwnode_property_read_string(child, "linux,default-trigger", 410 &pdata->leds[reg].default_trigger); 411 } 412 413 pdata->num_leds = chip->bits; 414 415 return pdata; 416 } 417 418 static const struct of_device_id of_pca955x_match[] = { 419 { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, 420 { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, 421 { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, 422 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 }, 423 { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, 424 {}, 425 }; 426 MODULE_DEVICE_TABLE(of, of_pca955x_match); 427 428 static int pca955x_probe(struct i2c_client *client, 429 const struct i2c_device_id *id) 430 { 431 struct pca955x *pca955x; 432 struct pca955x_led *pca955x_led; 433 struct pca955x_chipdef *chip; 434 struct i2c_adapter *adapter; 435 int i, err; 436 struct pca955x_platform_data *pdata; 437 int ngpios = 0; 438 439 chip = &pca955x_chipdefs[id->driver_data]; 440 adapter = client->adapter; 441 pdata = dev_get_platdata(&client->dev); 442 if (!pdata) { 443 pdata = pca955x_get_pdata(client, chip); 444 if (IS_ERR(pdata)) 445 return PTR_ERR(pdata); 446 } 447 448 /* Make sure the slave address / chip type combo given is possible */ 449 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 450 chip->slv_addr) { 451 dev_err(&client->dev, "invalid slave address %02x\n", 452 client->addr); 453 return -ENODEV; 454 } 455 456 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 457 "slave address 0x%02x\n", 458 client->name, chip->bits, client->addr); 459 460 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 461 return -EIO; 462 463 if (pdata->num_leds != chip->bits) { 464 dev_err(&client->dev, 465 "board info claims %d LEDs on a %d-bit chip\n", 466 pdata->num_leds, chip->bits); 467 return -ENODEV; 468 } 469 470 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 471 if (!pca955x) 472 return -ENOMEM; 473 474 pca955x->leds = devm_kcalloc(&client->dev, 475 chip->bits, sizeof(*pca955x_led), GFP_KERNEL); 476 if (!pca955x->leds) 477 return -ENOMEM; 478 479 i2c_set_clientdata(client, pca955x); 480 481 mutex_init(&pca955x->lock); 482 pca955x->client = client; 483 pca955x->chipdef = chip; 484 485 for (i = 0; i < chip->bits; i++) { 486 pca955x_led = &pca955x->leds[i]; 487 pca955x_led->led_num = i; 488 pca955x_led->pca955x = pca955x; 489 pca955x_led->type = pdata->leds[i].type; 490 491 switch (pca955x_led->type) { 492 case PCA955X_TYPE_NONE: 493 break; 494 case PCA955X_TYPE_GPIO: 495 ngpios++; 496 break; 497 case PCA955X_TYPE_LED: 498 /* 499 * Platform data can specify LED names and 500 * default triggers 501 */ 502 if (pdata->leds[i].name[0] == '\0') 503 snprintf(pdata->leds[i].name, 504 sizeof(pdata->leds[i].name), "%d", i); 505 506 snprintf(pca955x_led->name, 507 sizeof(pca955x_led->name), "pca955x:%s", 508 pdata->leds[i].name); 509 510 if (pdata->leds[i].default_trigger) 511 pca955x_led->led_cdev.default_trigger = 512 pdata->leds[i].default_trigger; 513 514 pca955x_led->led_cdev.name = pca955x_led->name; 515 pca955x_led->led_cdev.brightness_set_blocking = 516 pca955x_led_set; 517 518 err = devm_led_classdev_register(&client->dev, 519 &pca955x_led->led_cdev); 520 if (err) 521 return err; 522 523 /* Turn off LED */ 524 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF); 525 if (err) 526 return err; 527 } 528 } 529 530 /* PWM0 is used for half brightness or 50% duty cycle */ 531 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 532 if (err) 533 return err; 534 535 /* PWM1 is used for variable brightness, default to OFF */ 536 err = pca955x_write_pwm(client, 1, 0); 537 if (err) 538 return err; 539 540 /* Set to fast frequency so we do not see flashing */ 541 err = pca955x_write_psc(client, 0, 0); 542 if (err) 543 return err; 544 err = pca955x_write_psc(client, 1, 0); 545 if (err) 546 return err; 547 548 #ifdef CONFIG_LEDS_PCA955X_GPIO 549 if (ngpios) { 550 pca955x->gpio.label = "gpio-pca955x"; 551 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 552 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 553 pca955x->gpio.set = pca955x_gpio_set_value; 554 pca955x->gpio.get = pca955x_gpio_get_value; 555 pca955x->gpio.request = pca955x_gpio_request_pin; 556 pca955x->gpio.can_sleep = 1; 557 pca955x->gpio.base = -1; 558 pca955x->gpio.ngpio = ngpios; 559 pca955x->gpio.parent = &client->dev; 560 pca955x->gpio.owner = THIS_MODULE; 561 562 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 563 pca955x); 564 if (err) { 565 /* Use data->gpio.dev as a flag for freeing gpiochip */ 566 pca955x->gpio.parent = NULL; 567 dev_warn(&client->dev, "could not add gpiochip\n"); 568 return err; 569 } 570 dev_info(&client->dev, "gpios %i...%i\n", 571 pca955x->gpio.base, pca955x->gpio.base + 572 pca955x->gpio.ngpio - 1); 573 } 574 #endif 575 576 return 0; 577 } 578 579 static struct i2c_driver pca955x_driver = { 580 .driver = { 581 .name = "leds-pca955x", 582 .of_match_table = of_pca955x_match, 583 }, 584 .probe = pca955x_probe, 585 .id_table = pca955x_id, 586 }; 587 588 module_i2c_driver(pca955x_driver); 589 590 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 591 MODULE_DESCRIPTION("PCA955x LED driver"); 592 MODULE_LICENSE("GPL v2"); 593