drivers/leds/leds-pca963x.c

   1 /*
   2  * Copyright 2011 bct electronic GmbH
   3  * Copyright 2013 Qtechnology/AS
   4  *
   5  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
   6  * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
   7  *
   8  * Based on leds-pca955x.c
   9  *
  10  * This file is subject to the terms and conditions of version 2 of
  11  * the GNU General Public License.  See the file COPYING in the main
  12  * directory of this archive for more details.
  13  *
  14  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
  15  * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
  16  *
  17  * Note that hardware blinking violates the leds infrastructure driver
  18  * interface since the hardware only supports blinking all LEDs with the
  19  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
  20  * blink will actually blink but all LEDs that are set to blink will blink
  21  * in identical fashion.  The delay_on/delay_off values of the last LED
  22  * that is set to blink will be used for all of the blinking LEDs.
  23  * Hardware blinking is disabled by default but can be enabled by setting
  24  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
  25  * or by adding the 'nxp,hw-blink' property to the DTS.
  26  */
  27
  28 #include <linux/acpi.h>
  29 #include <linux/module.h>
  30 #include <linux/delay.h>
  31 #include <linux/string.h>
  32 #include <linux/ctype.h>
  33 #include <linux/leds.h>
  34 #include <linux/err.h>
  35 #include <linux/i2c.h>
  36 #include <linux/slab.h>
  37 #include <linux/of.h>
  38 #include <linux/platform_data/leds-pca963x.h>
  39
  40 /* LED select registers determine the source that drives LED outputs */
  41 #define PCA963X_LED_OFF         0x0     /* LED driver off */
  42 #define PCA963X_LED_ON          0x1     /* LED driver on */
  43 #define PCA963X_LED_PWM         0x2     /* Controlled through PWM */
  44 #define PCA963X_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  45
  46 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  47
  48 #define PCA963X_MODE1           0x00
  49 #define PCA963X_MODE2           0x01
  50 #define PCA963X_PWM_BASE        0x02
  51
  52 enum pca963x_type {
  53         pca9633,
  54         pca9634,
  55         pca9635,
  56 };
  57
  58 struct pca963x_chipdef {
  59         u8                      grppwm;
  60         u8                      grpfreq;
  61         u8                      ledout_base;
  62         int                     n_leds;
  63         unsigned int            scaling;
  64 };
  65
  66 static struct pca963x_chipdef pca963x_chipdefs[] = {
  67         [pca9633] = {
  68                 .grppwm         = 0x6,
  69                 .grpfreq        = 0x7,
  70                 .ledout_base    = 0x8,
  71                 .n_leds         = 4,
  72         },
  73         [pca9634] = {
  74                 .grppwm         = 0xa,
  75                 .grpfreq        = 0xb,
  76                 .ledout_base    = 0xc,
  77                 .n_leds         = 8,
  78         },
  79         [pca9635] = {
  80                 .grppwm         = 0x12,
  81                 .grpfreq        = 0x13,
  82                 .ledout_base    = 0x14,
  83                 .n_leds         = 16,
  84         },
  85 };
  86
  87 /* Total blink period in milliseconds */
  88 #define PCA963X_BLINK_PERIOD_MIN        42
  89 #define PCA963X_BLINK_PERIOD_MAX        10667
  90
  91 static const struct i2c_device_id pca963x_id[] = {
  92         { "pca9632", pca9633 },
  93         { "pca9633", pca9633 },
  94         { "pca9634", pca9634 },
  95         { "pca9635", pca9635 },
  96         { }
  97 };
  98 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  99
 100 static const struct acpi_device_id pca963x_acpi_ids[] = {
 101         { "PCA9632", pca9633 },
 102         { "PCA9633", pca9633 },
 103         { "PCA9634", pca9634 },
 104         { "PCA9635", pca9635 },
 105         { }
 106 };
 107 MODULE_DEVICE_TABLE(acpi, pca963x_acpi_ids);
 108
 109 struct pca963x_led;
 110
 111 struct pca963x {
 112         struct pca963x_chipdef *chipdef;
 113         struct mutex mutex;
 114         struct i2c_client *client;
 115         struct pca963x_led *leds;
 116         unsigned long leds_on;
 117 };
 118
 119 struct pca963x_led {
 120         struct pca963x *chip;
 121         struct led_classdev led_cdev;
 122         int led_num; /* 0 .. 15 potentially */
 123         char name[32];
 124         u8 gdc;
 125         u8 gfrq;
 126 };
 127
 128 static int pca963x_brightness(struct pca963x_led *pca963x,
 129                                enum led_brightness brightness)
 130 {
 131         u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 132                 + (pca963x->led_num / 4);
 133         u8 ledout;
 134         int shift = 2 * (pca963x->led_num % 4);
 135         u8 mask = 0x3 << shift;
 136         int ret;
 137
 138         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 139         switch (brightness) {
 140         case LED_FULL:
 141                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 142                         ledout_addr,
 143                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 144                 break;
 145         case LED_OFF:
 146                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 147                         ledout_addr, ledout & ~mask);
 148                 break;
 149         default:
 150                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 151                         PCA963X_PWM_BASE + pca963x->led_num,
 152                         brightness);
 153                 if (ret < 0)
 154                         return ret;
 155                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 156                         ledout_addr,
 157                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 158                 break;
 159         }
 160
 161         return ret;
 162 }
 163
 164 static void pca963x_blink(struct pca963x_led *pca963x)
 165 {
 166         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 167                 (pca963x->led_num / 4);
 168         u8 ledout;
 169         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 170                                                         PCA963X_MODE2);
 171         int shift = 2 * (pca963x->led_num % 4);
 172         u8 mask = 0x3 << shift;
 173
 174         i2c_smbus_write_byte_data(pca963x->chip->client,
 175                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 176
 177         i2c_smbus_write_byte_data(pca963x->chip->client,
 178                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 179
 180         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 181                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 182                         mode2 | PCA963X_MODE2_DMBLNK);
 183
 184         mutex_lock(&pca963x->chip->mutex);
 185         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 186         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 187                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 188                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 189         mutex_unlock(&pca963x->chip->mutex);
 190 }
 191
 192 static int pca963x_power_state(struct pca963x_led *pca963x)
 193 {
 194         unsigned long *leds_on = &pca963x->chip->leds_on;
 195         unsigned long cached_leds = pca963x->chip->leds_on;
 196
 197         if (pca963x->led_cdev.brightness)
 198                 set_bit(pca963x->led_num, leds_on);
 199         else
 200                 clear_bit(pca963x->led_num, leds_on);
 201
 202         if (!(*leds_on) != !cached_leds)
 203                 return i2c_smbus_write_byte_data(pca963x->chip->client,
 204                         PCA963X_MODE1, *leds_on ? 0 : BIT(4));
 205
 206         return 0;
 207 }
 208
 209 static int pca963x_led_set(struct led_classdev *led_cdev,
 210         enum led_brightness value)
 211 {
 212         struct pca963x_led *pca963x;
 213         int ret;
 214
 215         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 216
 217         mutex_lock(&pca963x->chip->mutex);
 218
 219         ret = pca963x_brightness(pca963x, value);
 220         if (ret < 0)
 221                 goto unlock;
 222         ret = pca963x_power_state(pca963x);
 223
 224 unlock:
 225         mutex_unlock(&pca963x->chip->mutex);
 226         return ret;
 227 }
 228
 229 static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
 230         unsigned int val)
 231 {
 232         unsigned int scaling = pca963x->chip->chipdef->scaling;
 233
 234         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 235 }
 236
 237 static int pca963x_blink_set(struct led_classdev *led_cdev,
 238                 unsigned long *delay_on, unsigned long *delay_off)
 239 {
 240         struct pca963x_led *pca963x;
 241         unsigned long time_on, time_off, period;
 242         u8 gdc, gfrq;
 243
 244         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 245
 246         time_on = *delay_on;
 247         time_off = *delay_off;
 248
 249         /* If both zero, pick reasonable defaults of 500ms each */
 250         if (!time_on && !time_off) {
 251                 time_on = 500;
 252                 time_off = 500;
 253         }
 254
 255         period = pca963x_period_scale(pca963x, time_on + time_off);
 256
 257         /* If period not supported by hardware, default to someting sane. */
 258         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 259             (period > PCA963X_BLINK_PERIOD_MAX)) {
 260                 time_on = 500;
 261                 time_off = 500;
 262                 period = pca963x_period_scale(pca963x, 1000);
 263         }
 264
 265         /*
 266          * From manual: duty cycle = (GDC / 256) ->
 267          *      (time_on / period) = (GDC / 256) ->
 268          *              GDC = ((time_on * 256) / period)
 269          */
 270         gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
 271
 272         /*
 273          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 274          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 275          *              GFRQ = ((period * 24 / 1000) - 1)
 276          */
 277         gfrq = (period * 24 / 1000) - 1;
 278
 279         pca963x->gdc = gdc;
 280         pca963x->gfrq = gfrq;
 281
 282         pca963x_blink(pca963x);
 283
 284         *delay_on = time_on;
 285         *delay_off = time_off;
 286
 287         return 0;
 288 }
 289
 290 #if IS_ENABLED(CONFIG_OF)
 291 static struct pca963x_platform_data *
 292 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 293 {
 294         struct device_node *np = client->dev.of_node, *child;
 295         struct pca963x_platform_data *pdata;
 296         struct led_info *pca963x_leds;
 297         int count;
 298
 299         count = of_get_child_count(np);
 300         if (!count || count > chip->n_leds)
 301                 return ERR_PTR(-ENODEV);
 302
 303         pca963x_leds = devm_kcalloc(&client->dev,
 304                         chip->n_leds, sizeof(struct led_info), GFP_KERNEL);
 305         if (!pca963x_leds)
 306                 return ERR_PTR(-ENOMEM);
 307
 308         for_each_child_of_node(np, child) {
 309                 struct led_info led = {};
 310                 u32 reg;
 311                 int res;
 312
 313                 res = of_property_read_u32(child, "reg", &reg);
 314                 if ((res != 0) || (reg >= chip->n_leds))
 315                         continue;
 316                 led.name =
 317                         of_get_property(child, "label", NULL) ? : child->name;
 318                 led.default_trigger =
 319                         of_get_property(child, "linux,default-trigger", NULL);
 320                 pca963x_leds[reg] = led;
 321         }
 322         pdata = devm_kzalloc(&client->dev,
 323                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 324         if (!pdata)
 325                 return ERR_PTR(-ENOMEM);
 326
 327         pdata->leds.leds = pca963x_leds;
 328         pdata->leds.num_leds = chip->n_leds;
 329
 330         /* default to open-drain unless totem pole (push-pull) is specified */
 331         if (of_property_read_bool(np, "nxp,totem-pole"))
 332                 pdata->outdrv = PCA963X_TOTEM_POLE;
 333         else
 334                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 335
 336         /* default to software blinking unless hardware blinking is specified */
 337         if (of_property_read_bool(np, "nxp,hw-blink"))
 338                 pdata->blink_type = PCA963X_HW_BLINK;
 339         else
 340                 pdata->blink_type = PCA963X_SW_BLINK;
 341
 342         if (of_property_read_u32(np, "nxp,period-scale", &chip->scaling))
 343                 chip->scaling = 1000;
 344
 345         /* default to non-inverted output, unless inverted is specified */
 346         if (of_property_read_bool(np, "nxp,inverted-out"))
 347                 pdata->dir = PCA963X_INVERTED;
 348         else
 349                 pdata->dir = PCA963X_NORMAL;
 350
 351         return pdata;
 352 }
 353
 354 static const struct of_device_id of_pca963x_match[] = {
 355         { .compatible = "nxp,pca9632", },
 356         { .compatible = "nxp,pca9633", },
 357         { .compatible = "nxp,pca9634", },
 358         { .compatible = "nxp,pca9635", },
 359         {},
 360 };
 361 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 362 #else
 363 static struct pca963x_platform_data *
 364 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 365 {
 366         return ERR_PTR(-ENODEV);
 367 }
 368 #endif
 369
 370 static int pca963x_probe(struct i2c_client *client,
 371                                         const struct i2c_device_id *id)
 372 {
 373         struct pca963x *pca963x_chip;
 374         struct pca963x_led *pca963x;
 375         struct pca963x_platform_data *pdata;
 376         struct pca963x_chipdef *chip;
 377         int i, err;
 378
 379         if (id) {
 380                 chip = &pca963x_chipdefs[id->driver_data];
 381         } else {
 382                 const struct acpi_device_id *acpi_id;
 383
 384                 acpi_id = acpi_match_device(pca963x_acpi_ids, &client->dev);
 385                 if (!acpi_id)
 386                         return -ENODEV;
 387                 chip = &pca963x_chipdefs[acpi_id->driver_data];
 388         }
 389         pdata = dev_get_platdata(&client->dev);
 390
 391         if (!pdata) {
 392                 pdata = pca963x_dt_init(client, chip);
 393                 if (IS_ERR(pdata)) {
 394                         dev_warn(&client->dev, "could not parse configuration\n");
 395                         pdata = NULL;
 396                 }
 397         }
 398
 399         if (pdata && (pdata->leds.num_leds < 1 ||
 400                                  pdata->leds.num_leds > chip->n_leds)) {
 401                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 402                                                                 chip->n_leds);
 403                 return -EINVAL;
 404         }
 405
 406         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 407                                                                 GFP_KERNEL);
 408         if (!pca963x_chip)
 409                 return -ENOMEM;
 410         pca963x = devm_kcalloc(&client->dev, chip->n_leds, sizeof(*pca963x),
 411                                                                 GFP_KERNEL);
 412         if (!pca963x)
 413                 return -ENOMEM;
 414
 415         i2c_set_clientdata(client, pca963x_chip);
 416
 417         mutex_init(&pca963x_chip->mutex);
 418         pca963x_chip->chipdef = chip;
 419         pca963x_chip->client = client;
 420         pca963x_chip->leds = pca963x;
 421
 422         /* Turn off LEDs by default*/
 423         for (i = 0; i < chip->n_leds / 4; i++)
 424                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 425
 426         for (i = 0; i < chip->n_leds; i++) {
 427                 pca963x[i].led_num = i;
 428                 pca963x[i].chip = pca963x_chip;
 429
 430                 /* Platform data can specify LED names and default triggers */
 431                 if (pdata && i < pdata->leds.num_leds) {
 432                         if (pdata->leds.leds[i].name)
 433                                 snprintf(pca963x[i].name,
 434                                          sizeof(pca963x[i].name), "pca963x:%s",
 435                                          pdata->leds.leds[i].name);
 436                         if (pdata->leds.leds[i].default_trigger)
 437                                 pca963x[i].led_cdev.default_trigger =
 438                                         pdata->leds.leds[i].default_trigger;
 439                 }
 440                 if (!pdata || i >= pdata->leds.num_leds ||
 441                                                 !pdata->leds.leds[i].name)
 442                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 443                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 444                                  client->addr, i);
 445
 446                 pca963x[i].led_cdev.name = pca963x[i].name;
 447                 pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
 448
 449                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 450                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 451
 452                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 453                 if (err < 0)
 454                         goto exit;
 455         }
 456
 457         /* Disable LED all-call address, and power down initially */
 458         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 459
 460         if (pdata) {
 461                 u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 462                                                     PCA963X_MODE2);
 463                 /* Configure output: open-drain or totem pole (push-pull) */
 464                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 465                         mode2 |= 0x01;
 466                 else
 467                         mode2 |= 0x05;
 468                 /* Configure direction: normal or inverted */
 469                 if (pdata->dir == PCA963X_INVERTED)
 470                         mode2 |= 0x10;
 471                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 472                                           mode2);
 473         }
 474
 475         return 0;
 476
 477 exit:
 478         while (i--)
 479                 led_classdev_unregister(&pca963x[i].led_cdev);
 480
 481         return err;
 482 }
 483
 484 static int pca963x_remove(struct i2c_client *client)
 485 {
 486         struct pca963x *pca963x = i2c_get_clientdata(client);
 487         int i;
 488
 489         for (i = 0; i < pca963x->chipdef->n_leds; i++)
 490                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 491
 492         return 0;
 493 }
 494
 495 static struct i2c_driver pca963x_driver = {
 496         .driver = {
 497                 .name   = "leds-pca963x",
 498                 .of_match_table = of_match_ptr(of_pca963x_match),
 499                 .acpi_match_table = ACPI_PTR(pca963x_acpi_ids),
 500         },
 501         .probe  = pca963x_probe,
 502         .remove = pca963x_remove,
 503         .id_table = pca963x_id,
 504 };
 505
 506 module_i2c_driver(pca963x_driver);
 507
 508 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 509 MODULE_DESCRIPTION("PCA963X LED driver");
 510 MODULE_LICENSE("GPL v2");