root/drivers/leds/leds-pca963x.c

DEFINITIONS

1. pca963x_brightness
2. pca963x_blink
3. pca963x_power_state
4. pca963x_led_set
5. pca963x_period_scale
6. pca963x_blink_set
7. pca963x_get_pdata
8. pca963x_probe
9. pca963x_remove

   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_OUTDRV    0x04    /* Open-drain or totem pole */
  44 #define PCA963X_MODE2_INVRT     0x10    /* Normal or inverted direction */
  45 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  46 
  47 #define PCA963X_MODE1           0x00
  48 #define PCA963X_MODE2           0x01
  49 #define PCA963X_PWM_BASE        0x02
  50 
  51 enum pca963x_type {
  52         pca9633,
  53         pca9634,
  54         pca9635,
  55 };
  56 
  57 struct pca963x_chipdef {
  58         u8                      grppwm;
  59         u8                      grpfreq;
  60         u8                      ledout_base;
  61         int                     n_leds;
  62         unsigned int            scaling;
  63 };
  64 
  65 static struct pca963x_chipdef pca963x_chipdefs[] = {
  66         [pca9633] = {
  67                 .grppwm         = 0x6,
  68                 .grpfreq        = 0x7,
  69                 .ledout_base    = 0x8,
  70                 .n_leds         = 4,
  71         },
  72         [pca9634] = {
  73                 .grppwm         = 0xa,
  74                 .grpfreq        = 0xb,
  75                 .ledout_base    = 0xc,
  76                 .n_leds         = 8,
  77         },
  78         [pca9635] = {
  79                 .grppwm         = 0x12,
  80                 .grpfreq        = 0x13,
  81                 .ledout_base    = 0x14,
  82                 .n_leds         = 16,
  83         },
  84 };
  85 
  86 /* Total blink period in milliseconds */
  87 #define PCA963X_BLINK_PERIOD_MIN        42
  88 #define PCA963X_BLINK_PERIOD_MAX        10667
  89 
  90 static const struct i2c_device_id pca963x_id[] = {
  91         { "pca9632", pca9633 },
  92         { "pca9633", pca9633 },
  93         { "pca9634", pca9634 },
  94         { "pca9635", pca9635 },
  95         { }
  96 };
  97 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  98 
  99 struct pca963x_led;
 100 
 101 struct pca963x {
 102         struct pca963x_chipdef *chipdef;
 103         struct mutex mutex;
 104         struct i2c_client *client;
 105         struct pca963x_led *leds;
 106         unsigned long leds_on;
 107 };
 108 
 109 struct pca963x_led {
 110         struct pca963x *chip;
 111         struct led_classdev led_cdev;
 112         int led_num; /* 0 .. 15 potentially */
 113         char name[32];
 114         u8 gdc;
 115         u8 gfrq;
 116 };
 117 
 118 static int pca963x_brightness(struct pca963x_led *pca963x,
 119                                enum led_brightness brightness)
 120 {
 121         u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 122                 + (pca963x->led_num / 4);
 123         u8 ledout;
 124         int shift = 2 * (pca963x->led_num % 4);
 125         u8 mask = 0x3 << shift;
 126         int ret;
 127 
 128         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 129         switch (brightness) {
 130         case LED_FULL:
 131                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 132                         ledout_addr,
 133                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 134                 break;
 135         case LED_OFF:
 136                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 137                         ledout_addr, ledout & ~mask);
 138                 break;
 139         default:
 140                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 141                         PCA963X_PWM_BASE + pca963x->led_num,
 142                         brightness);
 143                 if (ret < 0)
 144                         return ret;
 145                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 146                         ledout_addr,
 147                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 148                 break;
 149         }
 150 
 151         return ret;
 152 }
 153 
 154 static void pca963x_blink(struct pca963x_led *pca963x)
 155 {
 156         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 157                 (pca963x->led_num / 4);
 158         u8 ledout;
 159         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 160                                                         PCA963X_MODE2);
 161         int shift = 2 * (pca963x->led_num % 4);
 162         u8 mask = 0x3 << shift;
 163 
 164         i2c_smbus_write_byte_data(pca963x->chip->client,
 165                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 166 
 167         i2c_smbus_write_byte_data(pca963x->chip->client,
 168                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 169 
 170         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 171                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 172                         mode2 | PCA963X_MODE2_DMBLNK);
 173 
 174         mutex_lock(&pca963x->chip->mutex);
 175         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 176         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 177                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 178                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 179         mutex_unlock(&pca963x->chip->mutex);
 180 }
 181 
 182 static int pca963x_power_state(struct pca963x_led *pca963x)
 183 {
 184         unsigned long *leds_on = &pca963x->chip->leds_on;
 185         unsigned long cached_leds = pca963x->chip->leds_on;
 186 
 187         if (pca963x->led_cdev.brightness)
 188                 set_bit(pca963x->led_num, leds_on);
 189         else
 190                 clear_bit(pca963x->led_num, leds_on);
 191 
 192         if (!(*leds_on) != !cached_leds)
 193                 return i2c_smbus_write_byte_data(pca963x->chip->client,
 194                         PCA963X_MODE1, *leds_on ? 0 : BIT(4));
 195 
 196         return 0;
 197 }
 198 
 199 static int pca963x_led_set(struct led_classdev *led_cdev,
 200         enum led_brightness value)
 201 {
 202         struct pca963x_led *pca963x;
 203         int ret;
 204 
 205         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 206 
 207         mutex_lock(&pca963x->chip->mutex);
 208 
 209         ret = pca963x_brightness(pca963x, value);
 210         if (ret < 0)
 211                 goto unlock;
 212         ret = pca963x_power_state(pca963x);
 213 
 214 unlock:
 215         mutex_unlock(&pca963x->chip->mutex);
 216         return ret;
 217 }
 218 
 219 static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
 220         unsigned int val)
 221 {
 222         unsigned int scaling = pca963x->chip->chipdef->scaling;
 223 
 224         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 225 }
 226 
 227 static int pca963x_blink_set(struct led_classdev *led_cdev,
 228                 unsigned long *delay_on, unsigned long *delay_off)
 229 {
 230         struct pca963x_led *pca963x;
 231         unsigned long time_on, time_off, period;
 232         u8 gdc, gfrq;
 233 
 234         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 235 
 236         time_on = *delay_on;
 237         time_off = *delay_off;
 238 
 239         /* If both zero, pick reasonable defaults of 500ms each */
 240         if (!time_on && !time_off) {
 241                 time_on = 500;
 242                 time_off = 500;
 243         }
 244 
 245         period = pca963x_period_scale(pca963x, time_on + time_off);
 246 
 247         /* If period not supported by hardware, default to someting sane. */
 248         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 249             (period > PCA963X_BLINK_PERIOD_MAX)) {
 250                 time_on = 500;
 251                 time_off = 500;
 252                 period = pca963x_period_scale(pca963x, 1000);
 253         }
 254 
 255         /*
 256          * From manual: duty cycle = (GDC / 256) ->
 257          *      (time_on / period) = (GDC / 256) ->
 258          *              GDC = ((time_on * 256) / period)
 259          */
 260         gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
 261 
 262         /*
 263          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 264          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 265          *              GFRQ = ((period * 24 / 1000) - 1)
 266          */
 267         gfrq = (period * 24 / 1000) - 1;
 268 
 269         pca963x->gdc = gdc;
 270         pca963x->gfrq = gfrq;
 271 
 272         pca963x_blink(pca963x);
 273 
 274         *delay_on = time_on;
 275         *delay_off = time_off;
 276 
 277         return 0;
 278 }
 279 
 280 static struct pca963x_platform_data *
 281 pca963x_get_pdata(struct i2c_client *client, struct pca963x_chipdef *chip)
 282 {
 283         struct pca963x_platform_data *pdata;
 284         struct led_info *pca963x_leds;
 285         struct fwnode_handle *child;
 286         int count;
 287 
 288         count = device_get_child_node_count(&client->dev);
 289         if (!count || count > chip->n_leds)
 290                 return ERR_PTR(-ENODEV);
 291 
 292         pca963x_leds = devm_kcalloc(&client->dev,
 293                         chip->n_leds, sizeof(struct led_info), GFP_KERNEL);
 294         if (!pca963x_leds)
 295                 return ERR_PTR(-ENOMEM);
 296 
 297         device_for_each_child_node(&client->dev, child) {
 298                 struct led_info led = {};
 299                 u32 reg;
 300                 int res;
 301 
 302                 res = fwnode_property_read_u32(child, "reg", &reg);
 303                 if ((res != 0) || (reg >= chip->n_leds))
 304                         continue;
 305 
 306                 res = fwnode_property_read_string(child, "label", &led.name);
 307                 if ((res != 0) && is_of_node(child))
 308                         led.name = to_of_node(child)->name;
 309 
 310                 fwnode_property_read_string(child, "linux,default-trigger",
 311                                             &led.default_trigger);
 312 
 313                 pca963x_leds[reg] = led;
 314         }
 315         pdata = devm_kzalloc(&client->dev,
 316                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 317         if (!pdata)
 318                 return ERR_PTR(-ENOMEM);
 319 
 320         pdata->leds.leds = pca963x_leds;
 321         pdata->leds.num_leds = chip->n_leds;
 322 
 323         /* default to open-drain unless totem pole (push-pull) is specified */
 324         if (device_property_read_bool(&client->dev, "nxp,totem-pole"))
 325                 pdata->outdrv = PCA963X_TOTEM_POLE;
 326         else
 327                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 328 
 329         /* default to software blinking unless hardware blinking is specified */
 330         if (device_property_read_bool(&client->dev, "nxp,hw-blink"))
 331                 pdata->blink_type = PCA963X_HW_BLINK;
 332         else
 333                 pdata->blink_type = PCA963X_SW_BLINK;
 334 
 335         if (device_property_read_u32(&client->dev, "nxp,period-scale",
 336                                      &chip->scaling))
 337                 chip->scaling = 1000;
 338 
 339         /* default to non-inverted output, unless inverted is specified */
 340         if (device_property_read_bool(&client->dev, "nxp,inverted-out"))
 341                 pdata->dir = PCA963X_INVERTED;
 342         else
 343                 pdata->dir = PCA963X_NORMAL;
 344 
 345         return pdata;
 346 }
 347 
 348 static const struct of_device_id of_pca963x_match[] = {
 349         { .compatible = "nxp,pca9632", },
 350         { .compatible = "nxp,pca9633", },
 351         { .compatible = "nxp,pca9634", },
 352         { .compatible = "nxp,pca9635", },
 353         {},
 354 };
 355 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 356 
 357 static int pca963x_probe(struct i2c_client *client,
 358                                         const struct i2c_device_id *id)
 359 {
 360         struct pca963x *pca963x_chip;
 361         struct pca963x_led *pca963x;
 362         struct pca963x_platform_data *pdata;
 363         struct pca963x_chipdef *chip;
 364         int i, err;
 365 
 366         chip = &pca963x_chipdefs[id->driver_data];
 367         pdata = dev_get_platdata(&client->dev);
 368 
 369         if (!pdata) {
 370                 pdata = pca963x_get_pdata(client, chip);
 371                 if (IS_ERR(pdata)) {
 372                         dev_warn(&client->dev, "could not parse configuration\n");
 373                         pdata = NULL;
 374                 }
 375         }
 376 
 377         if (pdata && (pdata->leds.num_leds < 1 ||
 378                                  pdata->leds.num_leds > chip->n_leds)) {
 379                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 380                                                                 chip->n_leds);
 381                 return -EINVAL;
 382         }
 383 
 384         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 385                                                                 GFP_KERNEL);
 386         if (!pca963x_chip)
 387                 return -ENOMEM;
 388         pca963x = devm_kcalloc(&client->dev, chip->n_leds, sizeof(*pca963x),
 389                                                                 GFP_KERNEL);
 390         if (!pca963x)
 391                 return -ENOMEM;
 392 
 393         i2c_set_clientdata(client, pca963x_chip);
 394 
 395         mutex_init(&pca963x_chip->mutex);
 396         pca963x_chip->chipdef = chip;
 397         pca963x_chip->client = client;
 398         pca963x_chip->leds = pca963x;
 399 
 400         /* Turn off LEDs by default*/
 401         for (i = 0; i < chip->n_leds / 4; i++)
 402                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 403 
 404         for (i = 0; i < chip->n_leds; i++) {
 405                 pca963x[i].led_num = i;
 406                 pca963x[i].chip = pca963x_chip;
 407 
 408                 /* Platform data can specify LED names and default triggers */
 409                 if (pdata && i < pdata->leds.num_leds) {
 410                         if (pdata->leds.leds[i].name)
 411                                 snprintf(pca963x[i].name,
 412                                          sizeof(pca963x[i].name), "pca963x:%s",
 413                                          pdata->leds.leds[i].name);
 414                         if (pdata->leds.leds[i].default_trigger)
 415                                 pca963x[i].led_cdev.default_trigger =
 416                                         pdata->leds.leds[i].default_trigger;
 417                 }
 418                 if (!pdata || i >= pdata->leds.num_leds ||
 419                                                 !pdata->leds.leds[i].name)
 420                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 421                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 422                                  client->addr, i);
 423 
 424                 pca963x[i].led_cdev.name = pca963x[i].name;
 425                 pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
 426 
 427                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 428                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 429 
 430                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 431                 if (err < 0)
 432                         goto exit;
 433         }
 434 
 435         /* Disable LED all-call address, and power down initially */
 436         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 437 
 438         if (pdata) {
 439                 u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 440                                                     PCA963X_MODE2);
 441                 /* Configure output: open-drain or totem pole (push-pull) */
 442                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 443                         mode2 &= ~PCA963X_MODE2_OUTDRV;
 444                 else
 445                         mode2 |= PCA963X_MODE2_OUTDRV;
 446                 /* Configure direction: normal or inverted */
 447                 if (pdata->dir == PCA963X_INVERTED)
 448                         mode2 |= PCA963X_MODE2_INVRT;
 449                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 450                                           mode2);
 451         }
 452 
 453         return 0;
 454 
 455 exit:
 456         while (i--)
 457                 led_classdev_unregister(&pca963x[i].led_cdev);
 458 
 459         return err;
 460 }
 461 
 462 static int pca963x_remove(struct i2c_client *client)
 463 {
 464         struct pca963x *pca963x = i2c_get_clientdata(client);
 465         int i;
 466 
 467         for (i = 0; i < pca963x->chipdef->n_leds; i++)
 468                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 469 
 470         return 0;
 471 }
 472 
 473 static struct i2c_driver pca963x_driver = {
 474         .driver = {
 475                 .name   = "leds-pca963x",
 476                 .of_match_table = of_pca963x_match,
 477         },
 478         .probe  = pca963x_probe,
 479         .remove = pca963x_remove,
 480         .id_table = pca963x_id,
 481 };
 482 
 483 module_i2c_driver(pca963x_driver);
 484 
 485 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 486 MODULE_DESCRIPTION("PCA963X LED driver");
 487 MODULE_LICENSE("GPL v2");