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.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 pca9553, 69 }; 70 71 struct pca955x_chipdef { 72 int bits; 73 u8 slv_addr; /* 7-bit slave address mask */ 74 int slv_addr_shift; /* Number of bits to ignore */ 75 }; 76 77 static struct pca955x_chipdef pca955x_chipdefs[] = { 78 [pca9550] = { 79 .bits = 2, 80 .slv_addr = /* 110000x */ 0x60, 81 .slv_addr_shift = 1, 82 }, 83 [pca9551] = { 84 .bits = 8, 85 .slv_addr = /* 1100xxx */ 0x60, 86 .slv_addr_shift = 3, 87 }, 88 [pca9552] = { 89 .bits = 16, 90 .slv_addr = /* 1100xxx */ 0x60, 91 .slv_addr_shift = 3, 92 }, 93 [pca9553] = { 94 .bits = 4, 95 .slv_addr = /* 110001x */ 0x62, 96 .slv_addr_shift = 1, 97 }, 98 }; 99 100 static const struct i2c_device_id pca955x_id[] = { 101 { "pca9550", pca9550 }, 102 { "pca9551", pca9551 }, 103 { "pca9552", pca9552 }, 104 { "pca9553", pca9553 }, 105 { } 106 }; 107 MODULE_DEVICE_TABLE(i2c, pca955x_id); 108 109 struct pca955x { 110 struct mutex lock; 111 struct pca955x_led *leds; 112 struct pca955x_chipdef *chipdef; 113 struct i2c_client *client; 114 #ifdef CONFIG_LEDS_PCA955X_GPIO 115 struct gpio_chip gpio; 116 #endif 117 }; 118 119 struct pca955x_led { 120 struct pca955x *pca955x; 121 struct led_classdev led_cdev; 122 int led_num; /* 0 .. 15 potentially */ 123 char name[32]; 124 u32 type; 125 const char *default_trigger; 126 }; 127 128 struct pca955x_platform_data { 129 struct pca955x_led *leds; 130 int num_leds; 131 }; 132 133 /* 8 bits per input register */ 134 static inline int pca95xx_num_input_regs(int bits) 135 { 136 return (bits + 7) / 8; 137 } 138 139 /* 4 bits per LED selector register */ 140 static inline int pca95xx_num_led_regs(int bits) 141 { 142 return (bits + 3) / 4; 143 } 144 145 /* 146 * Return an LED selector register value based on an existing one, with 147 * the appropriate 2-bit state value set for the given LED number (0-3). 148 */ 149 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) 150 { 151 return (oldval & (~(0x3 << (led_num << 1)))) | 152 ((state & 0x3) << (led_num << 1)); 153 } 154 155 /* 156 * Write to frequency prescaler register, used to program the 157 * period of the PWM output. period = (PSCx + 1) / 38 158 */ 159 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) 160 { 161 struct pca955x *pca955x = i2c_get_clientdata(client); 162 int ret; 163 164 ret = i2c_smbus_write_byte_data(client, 165 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, 166 val); 167 if (ret < 0) 168 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 169 __func__, n, val, ret); 170 return ret; 171 } 172 173 /* 174 * Write to PWM register, which determines the duty cycle of the 175 * output. LED is OFF when the count is less than the value of this 176 * register, and ON when it is greater. If PWMx == 0, LED is always OFF. 177 * 178 * Duty cycle is (256 - PWMx) / 256 179 */ 180 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) 181 { 182 struct pca955x *pca955x = i2c_get_clientdata(client); 183 int ret; 184 185 ret = i2c_smbus_write_byte_data(client, 186 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, 187 val); 188 if (ret < 0) 189 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", 190 __func__, n, val, ret); 191 return ret; 192 } 193 194 /* 195 * Write to LED selector register, which determines the source that 196 * drives the LED output. 197 */ 198 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) 199 { 200 struct pca955x *pca955x = i2c_get_clientdata(client); 201 int ret; 202 203 ret = i2c_smbus_write_byte_data(client, 204 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, 205 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 int ret; 220 221 ret = i2c_smbus_read_byte_data(client, 222 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); 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_led_set(struct led_classdev *led_cdev, 233 enum led_brightness value) 234 { 235 struct pca955x_led *pca955x_led; 236 struct pca955x *pca955x; 237 u8 ls; 238 int chip_ls; /* which LSx to use (0-3 potentially) */ 239 int ls_led; /* which set of bits within LSx to use (0-3) */ 240 int ret; 241 242 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); 243 pca955x = pca955x_led->pca955x; 244 245 chip_ls = pca955x_led->led_num / 4; 246 ls_led = pca955x_led->led_num % 4; 247 248 mutex_lock(&pca955x->lock); 249 250 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); 251 if (ret) 252 goto out; 253 254 switch (value) { 255 case LED_FULL: 256 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); 257 break; 258 case LED_OFF: 259 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); 260 break; 261 case LED_HALF: 262 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); 263 break; 264 default: 265 /* 266 * Use PWM1 for all other values. This has the unwanted 267 * side effect of making all LEDs on the chip share the 268 * same brightness level if set to a value other than 269 * OFF, HALF, or FULL. But, this is probably better than 270 * just turning off for all other values. 271 */ 272 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); 273 if (ret) 274 goto out; 275 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); 276 break; 277 } 278 279 ret = pca955x_write_ls(pca955x->client, chip_ls, ls); 280 281 out: 282 mutex_unlock(&pca955x->lock); 283 284 return ret; 285 } 286 287 #ifdef CONFIG_LEDS_PCA955X_GPIO 288 /* 289 * Read the INPUT register, which contains the state of LEDs. 290 */ 291 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) 292 { 293 int ret = i2c_smbus_read_byte_data(client, n); 294 295 if (ret < 0) { 296 dev_err(&client->dev, "%s: reg 0x%x, err %d\n", 297 __func__, n, ret); 298 return ret; 299 } 300 *val = (u8)ret; 301 return 0; 302 303 } 304 305 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) 306 { 307 struct pca955x *pca955x = gpiochip_get_data(gc); 308 struct pca955x_led *led = &pca955x->leds[offset]; 309 310 if (led->type == PCA955X_TYPE_GPIO) 311 return 0; 312 313 return -EBUSY; 314 } 315 316 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, 317 int val) 318 { 319 struct pca955x *pca955x = gpiochip_get_data(gc); 320 struct pca955x_led *led = &pca955x->leds[offset]; 321 322 if (val) 323 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); 324 325 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); 326 } 327 328 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, 329 int val) 330 { 331 pca955x_set_value(gc, offset, val); 332 } 333 334 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) 335 { 336 struct pca955x *pca955x = gpiochip_get_data(gc); 337 struct pca955x_led *led = &pca955x->leds[offset]; 338 u8 reg = 0; 339 340 /* There is nothing we can do about errors */ 341 pca955x_read_input(pca955x->client, led->led_num / 8, ®); 342 343 return !!(reg & (1 << (led->led_num % 8))); 344 } 345 346 static int pca955x_gpio_direction_input(struct gpio_chip *gc, 347 unsigned int offset) 348 { 349 struct pca955x *pca955x = gpiochip_get_data(gc); 350 struct pca955x_led *led = &pca955x->leds[offset]; 351 352 /* To use as input ensure pin is not driven. */ 353 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); 354 } 355 356 static int pca955x_gpio_direction_output(struct gpio_chip *gc, 357 unsigned int offset, int val) 358 { 359 return pca955x_set_value(gc, offset, val); 360 } 361 #endif /* CONFIG_LEDS_PCA955X_GPIO */ 362 363 static struct pca955x_platform_data * 364 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) 365 { 366 struct pca955x_platform_data *pdata; 367 struct fwnode_handle *child; 368 int count; 369 370 count = device_get_child_node_count(&client->dev); 371 if (!count || count > chip->bits) 372 return ERR_PTR(-ENODEV); 373 374 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 375 if (!pdata) 376 return ERR_PTR(-ENOMEM); 377 378 pdata->leds = devm_kcalloc(&client->dev, 379 chip->bits, sizeof(struct pca955x_led), 380 GFP_KERNEL); 381 if (!pdata->leds) 382 return ERR_PTR(-ENOMEM); 383 384 device_for_each_child_node(&client->dev, child) { 385 const char *name; 386 u32 reg; 387 int res; 388 389 res = fwnode_property_read_u32(child, "reg", ®); 390 if ((res != 0) || (reg >= chip->bits)) 391 continue; 392 393 res = fwnode_property_read_string(child, "label", &name); 394 if ((res != 0) && is_of_node(child)) 395 name = to_of_node(child)->name; 396 397 snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name), 398 "%s", name); 399 400 pdata->leds[reg].type = PCA955X_TYPE_LED; 401 fwnode_property_read_u32(child, "type", &pdata->leds[reg].type); 402 fwnode_property_read_string(child, "linux,default-trigger", 403 &pdata->leds[reg].default_trigger); 404 } 405 406 pdata->num_leds = chip->bits; 407 408 return pdata; 409 } 410 411 static const struct of_device_id of_pca955x_match[] = { 412 { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, 413 { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, 414 { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, 415 { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, 416 {}, 417 }; 418 MODULE_DEVICE_TABLE(of, of_pca955x_match); 419 420 static int pca955x_probe(struct i2c_client *client, 421 const struct i2c_device_id *id) 422 { 423 struct pca955x *pca955x; 424 struct pca955x_led *pca955x_led; 425 struct pca955x_chipdef *chip; 426 struct i2c_adapter *adapter; 427 int i, err; 428 struct pca955x_platform_data *pdata; 429 int ngpios = 0; 430 431 chip = &pca955x_chipdefs[id->driver_data]; 432 adapter = to_i2c_adapter(client->dev.parent); 433 pdata = dev_get_platdata(&client->dev); 434 if (!pdata) { 435 pdata = pca955x_get_pdata(client, chip); 436 if (IS_ERR(pdata)) 437 return PTR_ERR(pdata); 438 } 439 440 /* Make sure the slave address / chip type combo given is possible */ 441 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != 442 chip->slv_addr) { 443 dev_err(&client->dev, "invalid slave address %02x\n", 444 client->addr); 445 return -ENODEV; 446 } 447 448 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " 449 "slave address 0x%02x\n", 450 client->name, chip->bits, client->addr); 451 452 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 453 return -EIO; 454 455 if (pdata->num_leds != chip->bits) { 456 dev_err(&client->dev, 457 "board info claims %d LEDs on a %d-bit chip\n", 458 pdata->num_leds, chip->bits); 459 return -ENODEV; 460 } 461 462 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); 463 if (!pca955x) 464 return -ENOMEM; 465 466 pca955x->leds = devm_kcalloc(&client->dev, 467 chip->bits, sizeof(*pca955x_led), GFP_KERNEL); 468 if (!pca955x->leds) 469 return -ENOMEM; 470 471 i2c_set_clientdata(client, pca955x); 472 473 mutex_init(&pca955x->lock); 474 pca955x->client = client; 475 pca955x->chipdef = chip; 476 477 for (i = 0; i < chip->bits; i++) { 478 pca955x_led = &pca955x->leds[i]; 479 pca955x_led->led_num = i; 480 pca955x_led->pca955x = pca955x; 481 pca955x_led->type = pdata->leds[i].type; 482 483 switch (pca955x_led->type) { 484 case PCA955X_TYPE_NONE: 485 break; 486 case PCA955X_TYPE_GPIO: 487 ngpios++; 488 break; 489 case PCA955X_TYPE_LED: 490 /* 491 * Platform data can specify LED names and 492 * default triggers 493 */ 494 if (pdata->leds[i].name[0] == '\0') 495 snprintf(pdata->leds[i].name, 496 sizeof(pdata->leds[i].name), "%d", i); 497 498 snprintf(pca955x_led->name, 499 sizeof(pca955x_led->name), "pca955x:%s", 500 pdata->leds[i].name); 501 502 if (pdata->leds[i].default_trigger) 503 pca955x_led->led_cdev.default_trigger = 504 pdata->leds[i].default_trigger; 505 506 pca955x_led->led_cdev.name = pca955x_led->name; 507 pca955x_led->led_cdev.brightness_set_blocking = 508 pca955x_led_set; 509 510 err = devm_led_classdev_register(&client->dev, 511 &pca955x_led->led_cdev); 512 if (err) 513 return err; 514 515 /* Turn off LED */ 516 err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF); 517 if (err) 518 return err; 519 } 520 } 521 522 /* PWM0 is used for half brightness or 50% duty cycle */ 523 err = pca955x_write_pwm(client, 0, 255 - LED_HALF); 524 if (err) 525 return err; 526 527 /* PWM1 is used for variable brightness, default to OFF */ 528 err = pca955x_write_pwm(client, 1, 0); 529 if (err) 530 return err; 531 532 /* Set to fast frequency so we do not see flashing */ 533 err = pca955x_write_psc(client, 0, 0); 534 if (err) 535 return err; 536 err = pca955x_write_psc(client, 1, 0); 537 if (err) 538 return err; 539 540 #ifdef CONFIG_LEDS_PCA955X_GPIO 541 if (ngpios) { 542 pca955x->gpio.label = "gpio-pca955x"; 543 pca955x->gpio.direction_input = pca955x_gpio_direction_input; 544 pca955x->gpio.direction_output = pca955x_gpio_direction_output; 545 pca955x->gpio.set = pca955x_gpio_set_value; 546 pca955x->gpio.get = pca955x_gpio_get_value; 547 pca955x->gpio.request = pca955x_gpio_request_pin; 548 pca955x->gpio.can_sleep = 1; 549 pca955x->gpio.base = -1; 550 pca955x->gpio.ngpio = ngpios; 551 pca955x->gpio.parent = &client->dev; 552 pca955x->gpio.owner = THIS_MODULE; 553 554 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, 555 pca955x); 556 if (err) { 557 /* Use data->gpio.dev as a flag for freeing gpiochip */ 558 pca955x->gpio.parent = NULL; 559 dev_warn(&client->dev, "could not add gpiochip\n"); 560 return err; 561 } 562 dev_info(&client->dev, "gpios %i...%i\n", 563 pca955x->gpio.base, pca955x->gpio.base + 564 pca955x->gpio.ngpio - 1); 565 } 566 #endif 567 568 return 0; 569 } 570 571 static struct i2c_driver pca955x_driver = { 572 .driver = { 573 .name = "leds-pca955x", 574 .of_match_table = of_pca955x_match, 575 }, 576 .probe = pca955x_probe, 577 .id_table = pca955x_id, 578 }; 579 580 module_i2c_driver(pca955x_driver); 581 582 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); 583 MODULE_DESCRIPTION("PCA955x LED driver"); 584 MODULE_LICENSE("GPL v2"); 585