drivers/leds/leds-pca955x.c

   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, &reg);
 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", &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");