drivers/leds/leds-pca963x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2011 bct electronic GmbH
   4  * Copyright 2013 Qtechnology/AS
   5  *
   6  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
   7  * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
   8  *
   9  * Based on leds-pca955x.c
  10  *
  11  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
  12  * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
  13  *
  14  * Note that hardware blinking violates the leds infrastructure driver
  15  * interface since the hardware only supports blinking all LEDs with the
  16  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
  17  * blink will actually blink but all LEDs that are set to blink will blink
  18  * in identical fashion.  The delay_on/delay_off values of the last LED
  19  * that is set to blink will be used for all of the blinking LEDs.
  20  * Hardware blinking is disabled by default but can be enabled by setting
  21  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
  22  * or by adding the 'nxp,hw-blink' property to the DTS.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/delay.h>
  27 #include <linux/string.h>
  28 #include <linux/ctype.h>
  29 #include <linux/leds.h>
  30 #include <linux/err.h>
  31 #include <linux/i2c.h>
  32 #include <linux/property.h>
  33 #include <linux/slab.h>
  34 #include <linux/of.h>
  35 #include <linux/platform_data/leds-pca963x.h>
  36
  37 /* LED select registers determine the source that drives LED outputs */
  38 #define PCA963X_LED_OFF         0x0     /* LED driver off */
  39 #define PCA963X_LED_ON          0x1     /* LED driver on */
  40 #define PCA963X_LED_PWM         0x2     /* Controlled through PWM */
  41 #define PCA963X_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  42
  43 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  44
  45 #define PCA963X_MODE1           0x00
  46 #define PCA963X_MODE2           0x01
  47 #define PCA963X_PWM_BASE        0x02
  48
  49 enum pca963x_type {
  50         pca9633,
  51         pca9634,
  52         pca9635,
  53 };
  54
  55 struct pca963x_chipdef {
  56         u8                      grppwm;
  57         u8                      grpfreq;
  58         u8                      ledout_base;
  59         int                     n_leds;
  60         unsigned int            scaling;
  61 };
  62
  63 static struct pca963x_chipdef pca963x_chipdefs[] = {
  64         [pca9633] = {
  65                 .grppwm         = 0x6,
  66                 .grpfreq        = 0x7,
  67                 .ledout_base    = 0x8,
  68                 .n_leds         = 4,
  69         },
  70         [pca9634] = {
  71                 .grppwm         = 0xa,
  72                 .grpfreq        = 0xb,
  73                 .ledout_base    = 0xc,
  74                 .n_leds         = 8,
  75         },
  76         [pca9635] = {
  77                 .grppwm         = 0x12,
  78                 .grpfreq        = 0x13,
  79                 .ledout_base    = 0x14,
  80                 .n_leds         = 16,
  81         },
  82 };
  83
  84 /* Total blink period in milliseconds */
  85 #define PCA963X_BLINK_PERIOD_MIN        42
  86 #define PCA963X_BLINK_PERIOD_MAX        10667
  87
  88 static const struct i2c_device_id pca963x_id[] = {
  89         { "pca9632", pca9633 },
  90         { "pca9633", pca9633 },
  91         { "pca9634", pca9634 },
  92         { "pca9635", pca9635 },
  93         { }
  94 };
  95 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  96
  97 struct pca963x_led;
  98
  99 struct pca963x {
 100         struct pca963x_chipdef *chipdef;
 101         struct mutex mutex;
 102         struct i2c_client *client;
 103         struct pca963x_led *leds;
 104         unsigned long leds_on;
 105 };
 106
 107 struct pca963x_led {
 108         struct pca963x *chip;
 109         struct led_classdev led_cdev;
 110         int led_num; /* 0 .. 15 potentially */
 111         char name[32];
 112         u8 gdc;
 113         u8 gfrq;
 114 };
 115
 116 static int pca963x_brightness(struct pca963x_led *pca963x,
 117                                enum led_brightness brightness)
 118 {
 119         u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 120                 + (pca963x->led_num / 4);
 121         u8 ledout;
 122         int shift = 2 * (pca963x->led_num % 4);
 123         u8 mask = 0x3 << shift;
 124         int ret;
 125
 126         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 127         switch (brightness) {
 128         case LED_FULL:
 129                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 130                         ledout_addr,
 131                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 132                 break;
 133         case LED_OFF:
 134                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 135                         ledout_addr, ledout & ~mask);
 136                 break;
 137         default:
 138                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 139                         PCA963X_PWM_BASE + pca963x->led_num,
 140                         brightness);
 141                 if (ret < 0)
 142                         return ret;
 143                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 144                         ledout_addr,
 145                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 146                 break;
 147         }
 148
 149         return ret;
 150 }
 151
 152 static void pca963x_blink(struct pca963x_led *pca963x)
 153 {
 154         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 155                 (pca963x->led_num / 4);
 156         u8 ledout;
 157         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 158                                                         PCA963X_MODE2);
 159         int shift = 2 * (pca963x->led_num % 4);
 160         u8 mask = 0x3 << shift;
 161
 162         i2c_smbus_write_byte_data(pca963x->chip->client,
 163                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 164
 165         i2c_smbus_write_byte_data(pca963x->chip->client,
 166                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 167
 168         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 169                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 170                         mode2 | PCA963X_MODE2_DMBLNK);
 171
 172         mutex_lock(&pca963x->chip->mutex);
 173         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 174         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 175                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 176                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 177         mutex_unlock(&pca963x->chip->mutex);
 178 }
 179
 180 static int pca963x_power_state(struct pca963x_led *pca963x)
 181 {
 182         unsigned long *leds_on = &pca963x->chip->leds_on;
 183         unsigned long cached_leds = pca963x->chip->leds_on;
 184
 185         if (pca963x->led_cdev.brightness)
 186                 set_bit(pca963x->led_num, leds_on);
 187         else
 188                 clear_bit(pca963x->led_num, leds_on);
 189
 190         if (!(*leds_on) != !cached_leds)
 191                 return i2c_smbus_write_byte_data(pca963x->chip->client,
 192                         PCA963X_MODE1, *leds_on ? 0 : BIT(4));
 193
 194         return 0;
 195 }
 196
 197 static int pca963x_led_set(struct led_classdev *led_cdev,
 198         enum led_brightness value)
 199 {
 200         struct pca963x_led *pca963x;
 201         int ret;
 202
 203         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 204
 205         mutex_lock(&pca963x->chip->mutex);
 206
 207         ret = pca963x_brightness(pca963x, value);
 208         if (ret < 0)
 209                 goto unlock;
 210         ret = pca963x_power_state(pca963x);
 211
 212 unlock:
 213         mutex_unlock(&pca963x->chip->mutex);
 214         return ret;
 215 }
 216
 217 static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
 218         unsigned int val)
 219 {
 220         unsigned int scaling = pca963x->chip->chipdef->scaling;
 221
 222         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 223 }
 224
 225 static int pca963x_blink_set(struct led_classdev *led_cdev,
 226                 unsigned long *delay_on, unsigned long *delay_off)
 227 {
 228         struct pca963x_led *pca963x;
 229         unsigned long time_on, time_off, period;
 230         u8 gdc, gfrq;
 231
 232         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 233
 234         time_on = *delay_on;
 235         time_off = *delay_off;
 236
 237         /* If both zero, pick reasonable defaults of 500ms each */
 238         if (!time_on && !time_off) {
 239                 time_on = 500;
 240                 time_off = 500;
 241         }
 242
 243         period = pca963x_period_scale(pca963x, time_on + time_off);
 244
 245         /* If period not supported by hardware, default to someting sane. */
 246         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 247             (period > PCA963X_BLINK_PERIOD_MAX)) {
 248                 time_on = 500;
 249                 time_off = 500;
 250                 period = pca963x_period_scale(pca963x, 1000);
 251         }
 252
 253         /*
 254          * From manual: duty cycle = (GDC / 256) ->
 255          *      (time_on / period) = (GDC / 256) ->
 256          *              GDC = ((time_on * 256) / period)
 257          */
 258         gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
 259
 260         /*
 261          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 262          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 263          *              GFRQ = ((period * 24 / 1000) - 1)
 264          */
 265         gfrq = (period * 24 / 1000) - 1;
 266
 267         pca963x->gdc = gdc;
 268         pca963x->gfrq = gfrq;
 269
 270         pca963x_blink(pca963x);
 271
 272         *delay_on = time_on;
 273         *delay_off = time_off;
 274
 275         return 0;
 276 }
 277
 278 static struct pca963x_platform_data *
 279 pca963x_get_pdata(struct i2c_client *client, struct pca963x_chipdef *chip)
 280 {
 281         struct pca963x_platform_data *pdata;
 282         struct led_info *pca963x_leds;
 283         struct fwnode_handle *child;
 284         int count;
 285
 286         count = device_get_child_node_count(&client->dev);
 287         if (!count || count > chip->n_leds)
 288                 return ERR_PTR(-ENODEV);
 289
 290         pca963x_leds = devm_kcalloc(&client->dev,
 291                         chip->n_leds, sizeof(struct led_info), GFP_KERNEL);
 292         if (!pca963x_leds)
 293                 return ERR_PTR(-ENOMEM);
 294
 295         device_for_each_child_node(&client->dev, child) {
 296                 struct led_info led = {};
 297                 u32 reg;
 298                 int res;
 299
 300                 res = fwnode_property_read_u32(child, "reg", &reg);
 301                 if ((res != 0) || (reg >= chip->n_leds))
 302                         continue;
 303
 304                 res = fwnode_property_read_string(child, "label", &led.name);
 305                 if ((res != 0) && is_of_node(child))
 306                         led.name = to_of_node(child)->name;
 307
 308                 fwnode_property_read_string(child, "linux,default-trigger",
 309                                             &led.default_trigger);
 310
 311                 pca963x_leds[reg] = led;
 312         }
 313         pdata = devm_kzalloc(&client->dev,
 314                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 315         if (!pdata)
 316                 return ERR_PTR(-ENOMEM);
 317
 318         pdata->leds.leds = pca963x_leds;
 319         pdata->leds.num_leds = chip->n_leds;
 320
 321         /* default to open-drain unless totem pole (push-pull) is specified */
 322         if (device_property_read_bool(&client->dev, "nxp,totem-pole"))
 323                 pdata->outdrv = PCA963X_TOTEM_POLE;
 324         else
 325                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 326
 327         /* default to software blinking unless hardware blinking is specified */
 328         if (device_property_read_bool(&client->dev, "nxp,hw-blink"))
 329                 pdata->blink_type = PCA963X_HW_BLINK;
 330         else
 331                 pdata->blink_type = PCA963X_SW_BLINK;
 332
 333         if (device_property_read_u32(&client->dev, "nxp,period-scale",
 334                                      &chip->scaling))
 335                 chip->scaling = 1000;
 336
 337         /* default to non-inverted output, unless inverted is specified */
 338         if (device_property_read_bool(&client->dev, "nxp,inverted-out"))
 339                 pdata->dir = PCA963X_INVERTED;
 340         else
 341                 pdata->dir = PCA963X_NORMAL;
 342
 343         return pdata;
 344 }
 345
 346 static const struct of_device_id of_pca963x_match[] = {
 347         { .compatible = "nxp,pca9632", },
 348         { .compatible = "nxp,pca9633", },
 349         { .compatible = "nxp,pca9634", },
 350         { .compatible = "nxp,pca9635", },
 351         {},
 352 };
 353 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 354
 355 static int pca963x_probe(struct i2c_client *client,
 356                                         const struct i2c_device_id *id)
 357 {
 358         struct pca963x *pca963x_chip;
 359         struct pca963x_led *pca963x;
 360         struct pca963x_platform_data *pdata;
 361         struct pca963x_chipdef *chip;
 362         int i, err;
 363
 364         chip = &pca963x_chipdefs[id->driver_data];
 365         pdata = dev_get_platdata(&client->dev);
 366
 367         if (!pdata) {
 368                 pdata = pca963x_get_pdata(client, chip);
 369                 if (IS_ERR(pdata)) {
 370                         dev_warn(&client->dev, "could not parse configuration\n");
 371                         pdata = NULL;
 372                 }
 373         }
 374
 375         if (pdata && (pdata->leds.num_leds < 1 ||
 376                                  pdata->leds.num_leds > chip->n_leds)) {
 377                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 378                                                                 chip->n_leds);
 379                 return -EINVAL;
 380         }
 381
 382         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 383                                                                 GFP_KERNEL);
 384         if (!pca963x_chip)
 385                 return -ENOMEM;
 386         pca963x = devm_kcalloc(&client->dev, chip->n_leds, sizeof(*pca963x),
 387                                                                 GFP_KERNEL);
 388         if (!pca963x)
 389                 return -ENOMEM;
 390
 391         i2c_set_clientdata(client, pca963x_chip);
 392
 393         mutex_init(&pca963x_chip->mutex);
 394         pca963x_chip->chipdef = chip;
 395         pca963x_chip->client = client;
 396         pca963x_chip->leds = pca963x;
 397
 398         /* Turn off LEDs by default*/
 399         for (i = 0; i < chip->n_leds / 4; i++)
 400                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 401
 402         for (i = 0; i < chip->n_leds; i++) {
 403                 pca963x[i].led_num = i;
 404                 pca963x[i].chip = pca963x_chip;
 405
 406                 /* Platform data can specify LED names and default triggers */
 407                 if (pdata && i < pdata->leds.num_leds) {
 408                         if (pdata->leds.leds[i].name)
 409                                 snprintf(pca963x[i].name,
 410                                          sizeof(pca963x[i].name), "pca963x:%s",
 411                                          pdata->leds.leds[i].name);
 412                         if (pdata->leds.leds[i].default_trigger)
 413                                 pca963x[i].led_cdev.default_trigger =
 414                                         pdata->leds.leds[i].default_trigger;
 415                 }
 416                 if (!pdata || i >= pdata->leds.num_leds ||
 417                                                 !pdata->leds.leds[i].name)
 418                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 419                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 420                                  client->addr, i);
 421
 422                 pca963x[i].led_cdev.name = pca963x[i].name;
 423                 pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
 424
 425                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 426                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 427
 428                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 429                 if (err < 0)
 430                         goto exit;
 431         }
 432
 433         /* Disable LED all-call address, and power down initially */
 434         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 435
 436         if (pdata) {
 437                 u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 438                                                     PCA963X_MODE2);
 439                 /* Configure output: open-drain or totem pole (push-pull) */
 440                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 441                         mode2 |= 0x01;
 442                 else
 443                         mode2 |= 0x05;
 444                 /* Configure direction: normal or inverted */
 445                 if (pdata->dir == PCA963X_INVERTED)
 446                         mode2 |= 0x10;
 447                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 448                                           mode2);
 449         }
 450
 451         return 0;
 452
 453 exit:
 454         while (i--)
 455                 led_classdev_unregister(&pca963x[i].led_cdev);
 456
 457         return err;
 458 }
 459
 460 static int pca963x_remove(struct i2c_client *client)
 461 {
 462         struct pca963x *pca963x = i2c_get_clientdata(client);
 463         int i;
 464
 465         for (i = 0; i < pca963x->chipdef->n_leds; i++)
 466                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 467
 468         return 0;
 469 }
 470
 471 static struct i2c_driver pca963x_driver = {
 472         .driver = {
 473                 .name   = "leds-pca963x",
 474                 .of_match_table = of_pca963x_match,
 475         },
 476         .probe  = pca963x_probe,
 477         .remove = pca963x_remove,
 478         .id_table = pca963x_id,
 479 };
 480
 481 module_i2c_driver(pca963x_driver);
 482
 483 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 484 MODULE_DESCRIPTION("PCA963X LED driver");
 485 MODULE_LICENSE("GPL v2");