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_OUTDRV    0x04    /* Open-drain or totem pole */
  47 #define PCA963X_MODE2_INVRT     0x10    /* Normal or inverted direction */
  48 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  49
  50 #define PCA963X_MODE1           0x00
  51 #define PCA963X_MODE2           0x01
  52 #define PCA963X_PWM_BASE        0x02
  53
  54 enum pca963x_type {
  55         pca9633,
  56         pca9634,
  57         pca9635,
  58 };
  59
  60 struct pca963x_chipdef {
  61         u8                      grppwm;
  62         u8                      grpfreq;
  63         u8                      ledout_base;
  64         int                     n_leds;
  65         unsigned int            scaling;
  66 };
  67
  68 static struct pca963x_chipdef pca963x_chipdefs[] = {
  69         [pca9633] = {
  70                 .grppwm         = 0x6,
  71                 .grpfreq        = 0x7,
  72                 .ledout_base    = 0x8,
  73                 .n_leds         = 4,
  74         },
  75         [pca9634] = {
  76                 .grppwm         = 0xa,
  77                 .grpfreq        = 0xb,
  78                 .ledout_base    = 0xc,
  79                 .n_leds         = 8,
  80         },
  81         [pca9635] = {
  82                 .grppwm         = 0x12,
  83                 .grpfreq        = 0x13,
  84                 .ledout_base    = 0x14,
  85                 .n_leds         = 16,
  86         },
  87 };
  88
  89 /* Total blink period in milliseconds */
  90 #define PCA963X_BLINK_PERIOD_MIN        42
  91 #define PCA963X_BLINK_PERIOD_MAX        10667
  92
  93 static const struct i2c_device_id pca963x_id[] = {
  94         { "pca9632", pca9633 },
  95         { "pca9633", pca9633 },
  96         { "pca9634", pca9634 },
  97         { "pca9635", pca9635 },
  98         { }
  99 };
 100 MODULE_DEVICE_TABLE(i2c, pca963x_id);
 101
 102 static const struct acpi_device_id pca963x_acpi_ids[] = {
 103         { "PCA9632", pca9633 },
 104         { "PCA9633", pca9633 },
 105         { "PCA9634", pca9634 },
 106         { "PCA9635", pca9635 },
 107         { }
 108 };
 109 MODULE_DEVICE_TABLE(acpi, pca963x_acpi_ids);
 110
 111 struct pca963x_led;
 112
 113 struct pca963x {
 114         struct pca963x_chipdef *chipdef;
 115         struct mutex mutex;
 116         struct i2c_client *client;
 117         struct pca963x_led *leds;
 118         unsigned long leds_on;
 119 };
 120
 121 struct pca963x_led {
 122         struct pca963x *chip;
 123         struct led_classdev led_cdev;
 124         int led_num; /* 0 .. 15 potentially */
 125         char name[32];
 126         u8 gdc;
 127         u8 gfrq;
 128 };
 129
 130 static int pca963x_brightness(struct pca963x_led *pca963x,
 131                                enum led_brightness brightness)
 132 {
 133         u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 134                 + (pca963x->led_num / 4);
 135         u8 ledout;
 136         int shift = 2 * (pca963x->led_num % 4);
 137         u8 mask = 0x3 << shift;
 138         int ret;
 139
 140         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 141         switch (brightness) {
 142         case LED_FULL:
 143                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 144                         ledout_addr,
 145                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 146                 break;
 147         case LED_OFF:
 148                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 149                         ledout_addr, ledout & ~mask);
 150                 break;
 151         default:
 152                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 153                         PCA963X_PWM_BASE + pca963x->led_num,
 154                         brightness);
 155                 if (ret < 0)
 156                         return ret;
 157                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 158                         ledout_addr,
 159                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 160                 break;
 161         }
 162
 163         return ret;
 164 }
 165
 166 static void pca963x_blink(struct pca963x_led *pca963x)
 167 {
 168         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 169                 (pca963x->led_num / 4);
 170         u8 ledout;
 171         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 172                                                         PCA963X_MODE2);
 173         int shift = 2 * (pca963x->led_num % 4);
 174         u8 mask = 0x3 << shift;
 175
 176         i2c_smbus_write_byte_data(pca963x->chip->client,
 177                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 178
 179         i2c_smbus_write_byte_data(pca963x->chip->client,
 180                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 181
 182         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 183                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 184                         mode2 | PCA963X_MODE2_DMBLNK);
 185
 186         mutex_lock(&pca963x->chip->mutex);
 187         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 188         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 189                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 190                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 191         mutex_unlock(&pca963x->chip->mutex);
 192 }
 193
 194 static int pca963x_power_state(struct pca963x_led *pca963x)
 195 {
 196         unsigned long *leds_on = &pca963x->chip->leds_on;
 197         unsigned long cached_leds = pca963x->chip->leds_on;
 198
 199         if (pca963x->led_cdev.brightness)
 200                 set_bit(pca963x->led_num, leds_on);
 201         else
 202                 clear_bit(pca963x->led_num, leds_on);
 203
 204         if (!(*leds_on) != !cached_leds)
 205                 return i2c_smbus_write_byte_data(pca963x->chip->client,
 206                         PCA963X_MODE1, *leds_on ? 0 : BIT(4));
 207
 208         return 0;
 209 }
 210
 211 static int pca963x_led_set(struct led_classdev *led_cdev,
 212         enum led_brightness value)
 213 {
 214         struct pca963x_led *pca963x;
 215         int ret;
 216
 217         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 218
 219         mutex_lock(&pca963x->chip->mutex);
 220
 221         ret = pca963x_brightness(pca963x, value);
 222         if (ret < 0)
 223                 goto unlock;
 224         ret = pca963x_power_state(pca963x);
 225
 226 unlock:
 227         mutex_unlock(&pca963x->chip->mutex);
 228         return ret;
 229 }
 230
 231 static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
 232         unsigned int val)
 233 {
 234         unsigned int scaling = pca963x->chip->chipdef->scaling;
 235
 236         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 237 }
 238
 239 static int pca963x_blink_set(struct led_classdev *led_cdev,
 240                 unsigned long *delay_on, unsigned long *delay_off)
 241 {
 242         struct pca963x_led *pca963x;
 243         unsigned long time_on, time_off, period;
 244         u8 gdc, gfrq;
 245
 246         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 247
 248         time_on = *delay_on;
 249         time_off = *delay_off;
 250
 251         /* If both zero, pick reasonable defaults of 500ms each */
 252         if (!time_on && !time_off) {
 253                 time_on = 500;
 254                 time_off = 500;
 255         }
 256
 257         period = pca963x_period_scale(pca963x, time_on + time_off);
 258
 259         /* If period not supported by hardware, default to someting sane. */
 260         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 261             (period > PCA963X_BLINK_PERIOD_MAX)) {
 262                 time_on = 500;
 263                 time_off = 500;
 264                 period = pca963x_period_scale(pca963x, 1000);
 265         }
 266
 267         /*
 268          * From manual: duty cycle = (GDC / 256) ->
 269          *      (time_on / period) = (GDC / 256) ->
 270          *              GDC = ((time_on * 256) / period)
 271          */
 272         gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
 273
 274         /*
 275          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 276          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 277          *              GFRQ = ((period * 24 / 1000) - 1)
 278          */
 279         gfrq = (period * 24 / 1000) - 1;
 280
 281         pca963x->gdc = gdc;
 282         pca963x->gfrq = gfrq;
 283
 284         pca963x_blink(pca963x);
 285
 286         *delay_on = time_on;
 287         *delay_off = time_off;
 288
 289         return 0;
 290 }
 291
 292 #if IS_ENABLED(CONFIG_OF)
 293 static struct pca963x_platform_data *
 294 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 295 {
 296         struct device_node *np = client->dev.of_node, *child;
 297         struct pca963x_platform_data *pdata;
 298         struct led_info *pca963x_leds;
 299         int count;
 300
 301         count = of_get_child_count(np);
 302         if (!count || count > chip->n_leds)
 303                 return ERR_PTR(-ENODEV);
 304
 305         pca963x_leds = devm_kcalloc(&client->dev,
 306                         chip->n_leds, sizeof(struct led_info), GFP_KERNEL);
 307         if (!pca963x_leds)
 308                 return ERR_PTR(-ENOMEM);
 309
 310         for_each_child_of_node(np, child) {
 311                 struct led_info led = {};
 312                 u32 reg;
 313                 int res;
 314
 315                 res = of_property_read_u32(child, "reg", &reg);
 316                 if ((res != 0) || (reg >= chip->n_leds))
 317                         continue;
 318                 led.name =
 319                         of_get_property(child, "label", NULL) ? : child->name;
 320                 led.default_trigger =
 321                         of_get_property(child, "linux,default-trigger", NULL);
 322                 pca963x_leds[reg] = led;
 323         }
 324         pdata = devm_kzalloc(&client->dev,
 325                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 326         if (!pdata)
 327                 return ERR_PTR(-ENOMEM);
 328
 329         pdata->leds.leds = pca963x_leds;
 330         pdata->leds.num_leds = chip->n_leds;
 331
 332         /* default to open-drain unless totem pole (push-pull) is specified */
 333         if (of_property_read_bool(np, "nxp,totem-pole"))
 334                 pdata->outdrv = PCA963X_TOTEM_POLE;
 335         else
 336                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 337
 338         /* default to software blinking unless hardware blinking is specified */
 339         if (of_property_read_bool(np, "nxp,hw-blink"))
 340                 pdata->blink_type = PCA963X_HW_BLINK;
 341         else
 342                 pdata->blink_type = PCA963X_SW_BLINK;
 343
 344         if (of_property_read_u32(np, "nxp,period-scale", &chip->scaling))
 345                 chip->scaling = 1000;
 346
 347         /* default to non-inverted output, unless inverted is specified */
 348         if (of_property_read_bool(np, "nxp,inverted-out"))
 349                 pdata->dir = PCA963X_INVERTED;
 350         else
 351                 pdata->dir = PCA963X_NORMAL;
 352
 353         return pdata;
 354 }
 355
 356 static const struct of_device_id of_pca963x_match[] = {
 357         { .compatible = "nxp,pca9632", },
 358         { .compatible = "nxp,pca9633", },
 359         { .compatible = "nxp,pca9634", },
 360         { .compatible = "nxp,pca9635", },
 361         {},
 362 };
 363 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 364 #else
 365 static struct pca963x_platform_data *
 366 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 367 {
 368         return ERR_PTR(-ENODEV);
 369 }
 370 #endif
 371
 372 static int pca963x_probe(struct i2c_client *client,
 373                                         const struct i2c_device_id *id)
 374 {
 375         struct pca963x *pca963x_chip;
 376         struct pca963x_led *pca963x;
 377         struct pca963x_platform_data *pdata;
 378         struct pca963x_chipdef *chip;
 379         int i, err;
 380
 381         if (id) {
 382                 chip = &pca963x_chipdefs[id->driver_data];
 383         } else {
 384                 const struct acpi_device_id *acpi_id;
 385
 386                 acpi_id = acpi_match_device(pca963x_acpi_ids, &client->dev);
 387                 if (!acpi_id)
 388                         return -ENODEV;
 389                 chip = &pca963x_chipdefs[acpi_id->driver_data];
 390         }
 391         pdata = dev_get_platdata(&client->dev);
 392
 393         if (!pdata) {
 394                 pdata = pca963x_dt_init(client, chip);
 395                 if (IS_ERR(pdata)) {
 396                         dev_warn(&client->dev, "could not parse configuration\n");
 397                         pdata = NULL;
 398                 }
 399         }
 400
 401         if (pdata && (pdata->leds.num_leds < 1 ||
 402                                  pdata->leds.num_leds > chip->n_leds)) {
 403                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 404                                                                 chip->n_leds);
 405                 return -EINVAL;
 406         }
 407
 408         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 409                                                                 GFP_KERNEL);
 410         if (!pca963x_chip)
 411                 return -ENOMEM;
 412         pca963x = devm_kcalloc(&client->dev, chip->n_leds, sizeof(*pca963x),
 413                                                                 GFP_KERNEL);
 414         if (!pca963x)
 415                 return -ENOMEM;
 416
 417         i2c_set_clientdata(client, pca963x_chip);
 418
 419         mutex_init(&pca963x_chip->mutex);
 420         pca963x_chip->chipdef = chip;
 421         pca963x_chip->client = client;
 422         pca963x_chip->leds = pca963x;
 423
 424         /* Turn off LEDs by default*/
 425         for (i = 0; i < chip->n_leds / 4; i++)
 426                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 427
 428         for (i = 0; i < chip->n_leds; i++) {
 429                 pca963x[i].led_num = i;
 430                 pca963x[i].chip = pca963x_chip;
 431
 432                 /* Platform data can specify LED names and default triggers */
 433                 if (pdata && i < pdata->leds.num_leds) {
 434                         if (pdata->leds.leds[i].name)
 435                                 snprintf(pca963x[i].name,
 436                                          sizeof(pca963x[i].name), "pca963x:%s",
 437                                          pdata->leds.leds[i].name);
 438                         if (pdata->leds.leds[i].default_trigger)
 439                                 pca963x[i].led_cdev.default_trigger =
 440                                         pdata->leds.leds[i].default_trigger;
 441                 }
 442                 if (!pdata || i >= pdata->leds.num_leds ||
 443                                                 !pdata->leds.leds[i].name)
 444                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 445                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 446                                  client->addr, i);
 447
 448                 pca963x[i].led_cdev.name = pca963x[i].name;
 449                 pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
 450
 451                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 452                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 453
 454                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 455                 if (err < 0)
 456                         goto exit;
 457         }
 458
 459         /* Disable LED all-call address, and power down initially */
 460         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 461
 462         if (pdata) {
 463                 u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 464                                                     PCA963X_MODE2);
 465                 /* Configure output: open-drain or totem pole (push-pull) */
 466                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 467                         mode2 &= ~PCA963X_MODE2_OUTDRV;
 468                 else
 469                         mode2 |= PCA963X_MODE2_OUTDRV;
 470                 /* Configure direction: normal or inverted */
 471                 if (pdata->dir == PCA963X_INVERTED)
 472                         mode2 |= PCA963X_MODE2_INVRT;
 473                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 474                                           mode2);
 475         }
 476
 477         return 0;
 478
 479 exit:
 480         while (i--)
 481                 led_classdev_unregister(&pca963x[i].led_cdev);
 482
 483         return err;
 484 }
 485
 486 static int pca963x_remove(struct i2c_client *client)
 487 {
 488         struct pca963x *pca963x = i2c_get_clientdata(client);
 489         int i;
 490
 491         for (i = 0; i < pca963x->chipdef->n_leds; i++)
 492                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 493
 494         return 0;
 495 }
 496
 497 static struct i2c_driver pca963x_driver = {
 498         .driver = {
 499                 .name   = "leds-pca963x",
 500                 .of_match_table = of_match_ptr(of_pca963x_match),
 501                 .acpi_match_table = ACPI_PTR(pca963x_acpi_ids),
 502         },
 503         .probe  = pca963x_probe,
 504         .remove = pca963x_remove,
 505         .id_table = pca963x_id,
 506 };
 507
 508 module_i2c_driver(pca963x_driver);
 509
 510 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 511 MODULE_DESCRIPTION("PCA963X LED driver");
 512 MODULE_LICENSE("GPL v2");