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/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 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 static const struct i2c_device_id pca955x_id[] = {
 108         { "pca9550", pca9550 },
 109         { "pca9551", pca9551 },
 110         { "pca9552", pca9552 },
 111         { "ibm-pca9552", ibm_pca9552 },
 112         { "pca9553", pca9553 },
 113         { }
 114 };
 115 MODULE_DEVICE_TABLE(i2c, pca955x_id);
 116
 117 struct pca955x {
 118         struct mutex lock;
 119         struct pca955x_led *leds;
 120         struct pca955x_chipdef  *chipdef;
 121         struct i2c_client       *client;
 122         unsigned long active_pins;
 123 #ifdef CONFIG_LEDS_PCA955X_GPIO
 124         struct gpio_chip gpio;
 125 #endif
 126 };
 127
 128 struct pca955x_led {
 129         struct pca955x  *pca955x;
 130         struct led_classdev     led_cdev;
 131         int                     led_num;        /* 0 .. 15 potentially */
 132         u32                     type;
 133         enum led_default_state  default_state;
 134         struct fwnode_handle    *fwnode;
 135 };
 136
 137 struct pca955x_platform_data {
 138         struct pca955x_led      *leds;
 139         int                     num_leds;
 140 };
 141
 142 /* 8 bits per input register */
 143 static inline int pca95xx_num_input_regs(int bits)
 144 {
 145         return (bits + 7) / 8;
 146 }
 147
 148 /*
 149  * Return an LED selector register value based on an existing one, with
 150  * the appropriate 2-bit state value set for the given LED number (0-3).
 151  */
 152 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
 153 {
 154         return (oldval & (~(0x3 << (led_num << 1)))) |
 155                 ((state & 0x3) << (led_num << 1));
 156 }
 157
 158 /*
 159  * Write to frequency prescaler register, used to program the
 160  * period of the PWM output.  period = (PSCx + 1) / 38
 161  */
 162 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
 163 {
 164         struct pca955x *pca955x = i2c_get_clientdata(client);
 165         u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
 166         int ret;
 167
 168         ret = i2c_smbus_write_byte_data(client, cmd, val);
 169         if (ret < 0)
 170                 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
 171                         __func__, n, val, ret);
 172         return ret;
 173 }
 174
 175 /*
 176  * Write to PWM register, which determines the duty cycle of the
 177  * output.  LED is OFF when the count is less than the value of this
 178  * register, and ON when it is greater.  If PWMx == 0, LED is always OFF.
 179  *
 180  * Duty cycle is (256 - PWMx) / 256
 181  */
 182 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
 183 {
 184         struct pca955x *pca955x = i2c_get_clientdata(client);
 185         u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
 186         int ret;
 187
 188         ret = i2c_smbus_write_byte_data(client, cmd, val);
 189         if (ret < 0)
 190                 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
 191                         __func__, n, val, ret);
 192         return ret;
 193 }
 194
 195 /*
 196  * Write to LED selector register, which determines the source that
 197  * drives the LED output.
 198  */
 199 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
 200 {
 201         struct pca955x *pca955x = i2c_get_clientdata(client);
 202         u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
 203         int ret;
 204
 205         ret = i2c_smbus_write_byte_data(client, cmd, 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         u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
 220         int ret;
 221
 222         ret = i2c_smbus_read_byte_data(client, cmd);
 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_read_pwm(struct i2c_client *client, int n, u8 *val)
 233 {
 234         struct pca955x *pca955x = i2c_get_clientdata(client);
 235         u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
 236         int ret;
 237
 238         ret = i2c_smbus_read_byte_data(client, cmd);
 239         if (ret < 0) {
 240                 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
 241                         __func__, n, ret);
 242                 return ret;
 243         }
 244         *val = (u8)ret;
 245         return 0;
 246 }
 247
 248 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
 249 {
 250         struct pca955x_led *pca955x_led = container_of(led_cdev,
 251                                                        struct pca955x_led,
 252                                                        led_cdev);
 253         struct pca955x *pca955x = pca955x_led->pca955x;
 254         u8 ls, pwm;
 255         int ret;
 256
 257         ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
 258         if (ret)
 259                 return ret;
 260
 261         ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
 262         switch (ls) {
 263         case PCA955X_LS_LED_ON:
 264                 ret = LED_FULL;
 265                 break;
 266         case PCA955X_LS_LED_OFF:
 267                 ret = LED_OFF;
 268                 break;
 269         case PCA955X_LS_BLINK0:
 270                 ret = LED_HALF;
 271                 break;
 272         case PCA955X_LS_BLINK1:
 273                 ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
 274                 if (ret)
 275                         return ret;
 276                 ret = 255 - pwm;
 277                 break;
 278         }
 279
 280         return ret;
 281 }
 282
 283 static int pca955x_led_set(struct led_classdev *led_cdev,
 284                             enum led_brightness value)
 285 {
 286         struct pca955x_led *pca955x_led;
 287         struct pca955x *pca955x;
 288         u8 ls;
 289         int chip_ls;    /* which LSx to use (0-3 potentially) */
 290         int ls_led;     /* which set of bits within LSx to use (0-3) */
 291         int ret;
 292
 293         pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
 294         pca955x = pca955x_led->pca955x;
 295
 296         chip_ls = pca955x_led->led_num / 4;
 297         ls_led = pca955x_led->led_num % 4;
 298
 299         mutex_lock(&pca955x->lock);
 300
 301         ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
 302         if (ret)
 303                 goto out;
 304
 305         switch (value) {
 306         case LED_FULL:
 307                 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
 308                 break;
 309         case LED_OFF:
 310                 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
 311                 break;
 312         case LED_HALF:
 313                 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
 314                 break;
 315         default:
 316                 /*
 317                  * Use PWM1 for all other values.  This has the unwanted
 318                  * side effect of making all LEDs on the chip share the
 319                  * same brightness level if set to a value other than
 320                  * OFF, HALF, or FULL.  But, this is probably better than
 321                  * just turning off for all other values.
 322                  */
 323                 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
 324                 if (ret)
 325                         goto out;
 326                 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
 327                 break;
 328         }
 329
 330         ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
 331
 332 out:
 333         mutex_unlock(&pca955x->lock);
 334
 335         return ret;
 336 }
 337
 338 #ifdef CONFIG_LEDS_PCA955X_GPIO
 339 /*
 340  * Read the INPUT register, which contains the state of LEDs.
 341  */
 342 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
 343 {
 344         int ret = i2c_smbus_read_byte_data(client, n);
 345
 346         if (ret < 0) {
 347                 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
 348                         __func__, n, ret);
 349                 return ret;
 350         }
 351         *val = (u8)ret;
 352         return 0;
 353
 354 }
 355
 356 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
 357 {
 358         struct pca955x *pca955x = gpiochip_get_data(gc);
 359
 360         return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
 361 }
 362
 363 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
 364 {
 365         struct pca955x *pca955x = gpiochip_get_data(gc);
 366
 367         clear_bit(offset, &pca955x->active_pins);
 368 }
 369
 370 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
 371                              int val)
 372 {
 373         struct pca955x *pca955x = gpiochip_get_data(gc);
 374         struct pca955x_led *led = &pca955x->leds[offset];
 375
 376         if (val)
 377                 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
 378
 379         return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
 380 }
 381
 382 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
 383                                    int val)
 384 {
 385         pca955x_set_value(gc, offset, val);
 386 }
 387
 388 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
 389 {
 390         struct pca955x *pca955x = gpiochip_get_data(gc);
 391         struct pca955x_led *led = &pca955x->leds[offset];
 392         u8 reg = 0;
 393
 394         /* There is nothing we can do about errors */
 395         pca955x_read_input(pca955x->client, led->led_num / 8, &reg);
 396
 397         return !!(reg & (1 << (led->led_num % 8)));
 398 }
 399
 400 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
 401                                         unsigned int offset)
 402 {
 403         struct pca955x *pca955x = gpiochip_get_data(gc);
 404         struct pca955x_led *led = &pca955x->leds[offset];
 405
 406         /* To use as input ensure pin is not driven. */
 407         return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
 408 }
 409
 410 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
 411                                          unsigned int offset, int val)
 412 {
 413         return pca955x_set_value(gc, offset, val);
 414 }
 415 #endif /* CONFIG_LEDS_PCA955X_GPIO */
 416
 417 static struct pca955x_platform_data *
 418 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
 419 {
 420         struct pca955x_platform_data *pdata;
 421         struct pca955x_led *led;
 422         struct fwnode_handle *child;
 423         int count;
 424
 425         count = device_get_child_node_count(&client->dev);
 426         if (count > chip->bits)
 427                 return ERR_PTR(-ENODEV);
 428
 429         pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 430         if (!pdata)
 431                 return ERR_PTR(-ENOMEM);
 432
 433         pdata->leds = devm_kcalloc(&client->dev,
 434                                    chip->bits, sizeof(struct pca955x_led),
 435                                    GFP_KERNEL);
 436         if (!pdata->leds)
 437                 return ERR_PTR(-ENOMEM);
 438
 439         device_for_each_child_node(&client->dev, child) {
 440                 u32 reg;
 441                 int res;
 442
 443                 res = fwnode_property_read_u32(child, "reg", &reg);
 444                 if ((res != 0) || (reg >= chip->bits))
 445                         continue;
 446
 447                 led = &pdata->leds[reg];
 448                 led->type = PCA955X_TYPE_LED;
 449                 led->fwnode = child;
 450                 led->default_state = led_init_default_state_get(child);
 451
 452                 fwnode_property_read_u32(child, "type", &led->type);
 453         }
 454
 455         pdata->num_leds = chip->bits;
 456
 457         return pdata;
 458 }
 459
 460 static const struct of_device_id of_pca955x_match[] = {
 461         { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
 462         { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
 463         { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
 464         { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
 465         { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
 466         {},
 467 };
 468 MODULE_DEVICE_TABLE(of, of_pca955x_match);
 469
 470 static int pca955x_probe(struct i2c_client *client)
 471 {
 472         struct pca955x *pca955x;
 473         struct pca955x_led *pca955x_led;
 474         struct pca955x_chipdef *chip;
 475         struct led_classdev *led;
 476         struct led_init_data init_data;
 477         struct i2c_adapter *adapter;
 478         int i, err;
 479         struct pca955x_platform_data *pdata;
 480         bool set_default_label = false;
 481         bool keep_pwm = false;
 482         char default_label[8];
 483         enum pca955x_type chip_type;
 484         const void *md = device_get_match_data(&client->dev);
 485
 486         if (md) {
 487                 chip_type = (enum pca955x_type)md;
 488         } else {
 489                 const struct i2c_device_id *id = i2c_match_id(pca955x_id,
 490                                                               client);
 491
 492                 if (id) {
 493                         chip_type = (enum pca955x_type)id->driver_data;
 494                 } else {
 495                         dev_err(&client->dev, "unknown chip\n");
 496                         return -ENODEV;
 497                 }
 498         }
 499
 500         chip = &pca955x_chipdefs[chip_type];
 501         adapter = client->adapter;
 502         pdata = dev_get_platdata(&client->dev);
 503         if (!pdata) {
 504                 pdata = pca955x_get_pdata(client, chip);
 505                 if (IS_ERR(pdata))
 506                         return PTR_ERR(pdata);
 507         }
 508
 509         /* Make sure the slave address / chip type combo given is possible */
 510         if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
 511             chip->slv_addr) {
 512                 dev_err(&client->dev, "invalid slave address %02x\n",
 513                         client->addr);
 514                 return -ENODEV;
 515         }
 516
 517         dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
 518                  "slave address 0x%02x\n", client->name, chip->bits,
 519                  client->addr);
 520
 521         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 522                 return -EIO;
 523
 524         if (pdata->num_leds != chip->bits) {
 525                 dev_err(&client->dev,
 526                         "board info claims %d LEDs on a %d-bit chip\n",
 527                         pdata->num_leds, chip->bits);
 528                 return -ENODEV;
 529         }
 530
 531         pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
 532         if (!pca955x)
 533                 return -ENOMEM;
 534
 535         pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
 536                                      sizeof(*pca955x_led), GFP_KERNEL);
 537         if (!pca955x->leds)
 538                 return -ENOMEM;
 539
 540         i2c_set_clientdata(client, pca955x);
 541
 542         mutex_init(&pca955x->lock);
 543         pca955x->client = client;
 544         pca955x->chipdef = chip;
 545
 546         init_data.devname_mandatory = false;
 547         init_data.devicename = "pca955x";
 548
 549         for (i = 0; i < chip->bits; i++) {
 550                 pca955x_led = &pca955x->leds[i];
 551                 pca955x_led->led_num = i;
 552                 pca955x_led->pca955x = pca955x;
 553                 pca955x_led->type = pdata->leds[i].type;
 554
 555                 switch (pca955x_led->type) {
 556                 case PCA955X_TYPE_NONE:
 557                 case PCA955X_TYPE_GPIO:
 558                         break;
 559                 case PCA955X_TYPE_LED:
 560                         led = &pca955x_led->led_cdev;
 561                         led->brightness_set_blocking = pca955x_led_set;
 562                         led->brightness_get = pca955x_led_get;
 563
 564                         if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) {
 565                                 err = pca955x_led_set(led, LED_OFF);
 566                                 if (err)
 567                                         return err;
 568                         } else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) {
 569                                 err = pca955x_led_set(led, LED_FULL);
 570                                 if (err)
 571                                         return err;
 572                         }
 573
 574                         init_data.fwnode = pdata->leds[i].fwnode;
 575
 576                         if (is_of_node(init_data.fwnode)) {
 577                                 if (to_of_node(init_data.fwnode)->name[0] ==
 578                                     '\0')
 579                                         set_default_label = true;
 580                                 else
 581                                         set_default_label = false;
 582                         } else {
 583                                 set_default_label = true;
 584                         }
 585
 586                         if (set_default_label) {
 587                                 snprintf(default_label, sizeof(default_label),
 588                                          "%d", i);
 589                                 init_data.default_label = default_label;
 590                         } else {
 591                                 init_data.default_label = NULL;
 592                         }
 593
 594                         err = devm_led_classdev_register_ext(&client->dev, led,
 595                                                              &init_data);
 596                         if (err)
 597                                 return err;
 598
 599                         set_bit(i, &pca955x->active_pins);
 600
 601                         /*
 602                          * For default-state == "keep", let the core update the
 603                          * brightness from the hardware, then check the
 604                          * brightness to see if it's using PWM1. If so, PWM1
 605                          * should not be written below.
 606                          */
 607                         if (pdata->leds[i].default_state == LEDS_DEFSTATE_KEEP) {
 608                                 if (led->brightness != LED_FULL &&
 609                                     led->brightness != LED_OFF &&
 610                                     led->brightness != LED_HALF)
 611                                         keep_pwm = true;
 612                         }
 613                 }
 614         }
 615
 616         /* PWM0 is used for half brightness or 50% duty cycle */
 617         err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
 618         if (err)
 619                 return err;
 620
 621         if (!keep_pwm) {
 622                 /* PWM1 is used for variable brightness, default to OFF */
 623                 err = pca955x_write_pwm(client, 1, 0);
 624                 if (err)
 625                         return err;
 626         }
 627
 628         /* Set to fast frequency so we do not see flashing */
 629         err = pca955x_write_psc(client, 0, 0);
 630         if (err)
 631                 return err;
 632         err = pca955x_write_psc(client, 1, 0);
 633         if (err)
 634                 return err;
 635
 636 #ifdef CONFIG_LEDS_PCA955X_GPIO
 637         pca955x->gpio.label = "gpio-pca955x";
 638         pca955x->gpio.direction_input = pca955x_gpio_direction_input;
 639         pca955x->gpio.direction_output = pca955x_gpio_direction_output;
 640         pca955x->gpio.set = pca955x_gpio_set_value;
 641         pca955x->gpio.get = pca955x_gpio_get_value;
 642         pca955x->gpio.request = pca955x_gpio_request_pin;
 643         pca955x->gpio.free = pca955x_gpio_free_pin;
 644         pca955x->gpio.can_sleep = 1;
 645         pca955x->gpio.base = -1;
 646         pca955x->gpio.ngpio = chip->bits;
 647         pca955x->gpio.parent = &client->dev;
 648         pca955x->gpio.owner = THIS_MODULE;
 649
 650         err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
 651                                      pca955x);
 652         if (err) {
 653                 /* Use data->gpio.dev as a flag for freeing gpiochip */
 654                 pca955x->gpio.parent = NULL;
 655                 dev_warn(&client->dev, "could not add gpiochip\n");
 656                 return err;
 657         }
 658         dev_info(&client->dev, "gpios %i...%i\n",
 659                  pca955x->gpio.base, pca955x->gpio.base +
 660                  pca955x->gpio.ngpio - 1);
 661 #endif
 662
 663         return 0;
 664 }
 665
 666 static struct i2c_driver pca955x_driver = {
 667         .driver = {
 668                 .name   = "leds-pca955x",
 669                 .of_match_table = of_pca955x_match,
 670         },
 671         .probe = pca955x_probe,
 672         .id_table = pca955x_id,
 673 };
 674
 675 module_i2c_driver(pca955x_driver);
 676
 677 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
 678 MODULE_DESCRIPTION("PCA955x LED driver");
 679 MODULE_LICENSE("GPL v2");