drivers/leds/leds-pca955x.c

   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, &reg);
 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", &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");