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/module.h>
  29 #include <linux/delay.h>
  30 #include <linux/string.h>
  31 #include <linux/ctype.h>
  32 #include <linux/leds.h>
  33 #include <linux/err.h>
  34 #include <linux/i2c.h>
  35 #include <linux/workqueue.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 };
  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 enum pca963x_cmd {
 100         BRIGHTNESS_SET,
 101         BLINK_SET,
 102 };
 103
 104 struct pca963x_led;
 105
 106 struct pca963x {
 107         struct pca963x_chipdef *chipdef;
 108         struct mutex mutex;
 109         struct i2c_client *client;
 110         struct pca963x_led *leds;
 111 };
 112
 113 struct pca963x_led {
 114         struct pca963x *chip;
 115         struct work_struct work;
 116         enum led_brightness brightness;
 117         struct led_classdev led_cdev;
 118         int led_num; /* 0 .. 15 potentially */
 119         enum pca963x_cmd cmd;
 120         char name[32];
 121         u8 gdc;
 122         u8 gfrq;
 123 };
 124
 125 static void pca963x_brightness_work(struct pca963x_led *pca963x)
 126 {
 127         u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 128                 + (pca963x->led_num / 4);
 129         u8 ledout;
 130         int shift = 2 * (pca963x->led_num % 4);
 131         u8 mask = 0x3 << shift;
 132
 133         mutex_lock(&pca963x->chip->mutex);
 134         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 135         switch (pca963x->brightness) {
 136         case LED_FULL:
 137                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 138                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 139                 break;
 140         case LED_OFF:
 141                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 142                         ledout & ~mask);
 143                 break;
 144         default:
 145                 i2c_smbus_write_byte_data(pca963x->chip->client,
 146                         PCA963X_PWM_BASE + pca963x->led_num,
 147                         pca963x->brightness);
 148                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 149                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 150                 break;
 151         }
 152         mutex_unlock(&pca963x->chip->mutex);
 153 }
 154
 155 static void pca963x_blink_work(struct pca963x_led *pca963x)
 156 {
 157         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 158                 (pca963x->led_num / 4);
 159         u8 ledout;
 160         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 161                                                         PCA963X_MODE2);
 162         int shift = 2 * (pca963x->led_num % 4);
 163         u8 mask = 0x3 << shift;
 164
 165         i2c_smbus_write_byte_data(pca963x->chip->client,
 166                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 167
 168         i2c_smbus_write_byte_data(pca963x->chip->client,
 169                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 170
 171         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 172                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 173                         mode2 | PCA963X_MODE2_DMBLNK);
 174
 175         mutex_lock(&pca963x->chip->mutex);
 176         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 177         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 178                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 179                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 180         mutex_unlock(&pca963x->chip->mutex);
 181 }
 182
 183 static void pca963x_work(struct work_struct *work)
 184 {
 185         struct pca963x_led *pca963x = container_of(work,
 186                 struct pca963x_led, work);
 187
 188         switch (pca963x->cmd) {
 189         case BRIGHTNESS_SET:
 190                 pca963x_brightness_work(pca963x);
 191                 break;
 192         case BLINK_SET:
 193                 pca963x_blink_work(pca963x);
 194                 break;
 195         }
 196 }
 197
 198 static void pca963x_led_set(struct led_classdev *led_cdev,
 199         enum led_brightness value)
 200 {
 201         struct pca963x_led *pca963x;
 202
 203         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 204
 205         pca963x->cmd = BRIGHTNESS_SET;
 206         pca963x->brightness = value;
 207
 208         /*
 209          * Must use workqueue for the actual I/O since I2C operations
 210          * can sleep.
 211          */
 212         schedule_work(&pca963x->work);
 213 }
 214
 215 static int pca963x_blink_set(struct led_classdev *led_cdev,
 216                 unsigned long *delay_on, unsigned long *delay_off)
 217 {
 218         struct pca963x_led *pca963x;
 219         unsigned long time_on, time_off, period;
 220         u8 gdc, gfrq;
 221
 222         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 223
 224         time_on = *delay_on;
 225         time_off = *delay_off;
 226
 227         /* If both zero, pick reasonable defaults of 500ms each */
 228         if (!time_on && !time_off) {
 229                 time_on = 500;
 230                 time_off = 500;
 231         }
 232
 233         period = time_on + time_off;
 234
 235         /* If period not supported by hardware, default to someting sane. */
 236         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 237             (period > PCA963X_BLINK_PERIOD_MAX)) {
 238                 time_on = 500;
 239                 time_off = 500;
 240                 period = time_on + time_off;
 241         }
 242
 243         /*
 244          * From manual: duty cycle = (GDC / 256) ->
 245          *      (time_on / period) = (GDC / 256) ->
 246          *              GDC = ((time_on * 256) / period)
 247          */
 248         gdc = (time_on * 256) / period;
 249
 250         /*
 251          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 252          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 253          *              GFRQ = ((period * 24 / 1000) - 1)
 254          */
 255         gfrq = (period * 24 / 1000) - 1;
 256
 257         pca963x->cmd = BLINK_SET;
 258         pca963x->gdc = gdc;
 259         pca963x->gfrq = gfrq;
 260
 261         /*
 262          * Must use workqueue for the actual I/O since I2C operations
 263          * can sleep.
 264          */
 265         schedule_work(&pca963x->work);
 266
 267         *delay_on = time_on;
 268         *delay_off = time_off;
 269
 270         return 0;
 271 }
 272
 273 #if IS_ENABLED(CONFIG_OF)
 274 static struct pca963x_platform_data *
 275 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 276 {
 277         struct device_node *np = client->dev.of_node, *child;
 278         struct pca963x_platform_data *pdata;
 279         struct led_info *pca963x_leds;
 280         int count;
 281
 282         count = of_get_child_count(np);
 283         if (!count || count > chip->n_leds)
 284                 return ERR_PTR(-ENODEV);
 285
 286         pca963x_leds = devm_kzalloc(&client->dev,
 287                         sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
 288         if (!pca963x_leds)
 289                 return ERR_PTR(-ENOMEM);
 290
 291         for_each_child_of_node(np, child) {
 292                 struct led_info led = {};
 293                 u32 reg;
 294                 int res;
 295
 296                 res = of_property_read_u32(child, "reg", &reg);
 297                 if ((res != 0) || (reg >= chip->n_leds))
 298                         continue;
 299                 led.name =
 300                         of_get_property(child, "label", NULL) ? : child->name;
 301                 led.default_trigger =
 302                         of_get_property(child, "linux,default-trigger", NULL);
 303                 pca963x_leds[reg] = led;
 304         }
 305         pdata = devm_kzalloc(&client->dev,
 306                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 307         if (!pdata)
 308                 return ERR_PTR(-ENOMEM);
 309
 310         pdata->leds.leds = pca963x_leds;
 311         pdata->leds.num_leds = chip->n_leds;
 312
 313         /* default to open-drain unless totem pole (push-pull) is specified */
 314         if (of_property_read_bool(np, "nxp,totem-pole"))
 315                 pdata->outdrv = PCA963X_TOTEM_POLE;
 316         else
 317                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 318
 319         /* default to software blinking unless hardware blinking is specified */
 320         if (of_property_read_bool(np, "nxp,hw-blink"))
 321                 pdata->blink_type = PCA963X_HW_BLINK;
 322         else
 323                 pdata->blink_type = PCA963X_SW_BLINK;
 324
 325         return pdata;
 326 }
 327
 328 static const struct of_device_id of_pca963x_match[] = {
 329         { .compatible = "nxp,pca9632", },
 330         { .compatible = "nxp,pca9633", },
 331         { .compatible = "nxp,pca9634", },
 332         { .compatible = "nxp,pca9635", },
 333         {},
 334 };
 335 #else
 336 static struct pca963x_platform_data *
 337 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 338 {
 339         return ERR_PTR(-ENODEV);
 340 }
 341 #endif
 342
 343 static int pca963x_probe(struct i2c_client *client,
 344                                         const struct i2c_device_id *id)
 345 {
 346         struct pca963x *pca963x_chip;
 347         struct pca963x_led *pca963x;
 348         struct pca963x_platform_data *pdata;
 349         struct pca963x_chipdef *chip;
 350         int i, err;
 351
 352         chip = &pca963x_chipdefs[id->driver_data];
 353         pdata = dev_get_platdata(&client->dev);
 354
 355         if (!pdata) {
 356                 pdata = pca963x_dt_init(client, chip);
 357                 if (IS_ERR(pdata)) {
 358                         dev_warn(&client->dev, "could not parse configuration\n");
 359                         pdata = NULL;
 360                 }
 361         }
 362
 363         if (pdata && (pdata->leds.num_leds < 1 ||
 364                                  pdata->leds.num_leds > chip->n_leds)) {
 365                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 366                                                                 chip->n_leds);
 367                 return -EINVAL;
 368         }
 369
 370         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 371                                                                 GFP_KERNEL);
 372         if (!pca963x_chip)
 373                 return -ENOMEM;
 374         pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
 375                                                                 GFP_KERNEL);
 376         if (!pca963x)
 377                 return -ENOMEM;
 378
 379         i2c_set_clientdata(client, pca963x_chip);
 380
 381         mutex_init(&pca963x_chip->mutex);
 382         pca963x_chip->chipdef = chip;
 383         pca963x_chip->client = client;
 384         pca963x_chip->leds = pca963x;
 385
 386         /* Turn off LEDs by default*/
 387         for (i = 0; i < chip->n_leds / 4; i++)
 388                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 389
 390         for (i = 0; i < chip->n_leds; i++) {
 391                 pca963x[i].led_num = i;
 392                 pca963x[i].chip = pca963x_chip;
 393
 394                 /* Platform data can specify LED names and default triggers */
 395                 if (pdata && i < pdata->leds.num_leds) {
 396                         if (pdata->leds.leds[i].name)
 397                                 snprintf(pca963x[i].name,
 398                                          sizeof(pca963x[i].name), "pca963x:%s",
 399                                          pdata->leds.leds[i].name);
 400                         if (pdata->leds.leds[i].default_trigger)
 401                                 pca963x[i].led_cdev.default_trigger =
 402                                         pdata->leds.leds[i].default_trigger;
 403                 }
 404                 if (!pdata || i >= pdata->leds.num_leds ||
 405                                                 !pdata->leds.leds[i].name)
 406                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 407                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 408                                  client->addr, i);
 409
 410                 pca963x[i].led_cdev.name = pca963x[i].name;
 411                 pca963x[i].led_cdev.brightness_set = pca963x_led_set;
 412
 413                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 414                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 415
 416                 INIT_WORK(&pca963x[i].work, pca963x_work);
 417
 418                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 419                 if (err < 0)
 420                         goto exit;
 421         }
 422
 423         /* Disable LED all-call address and set normal mode */
 424         i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);
 425
 426         if (pdata) {
 427                 /* Configure output: open-drain or totem pole (push-pull) */
 428                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 429                         i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);
 430                 else
 431                         i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x05);
 432         }
 433
 434         return 0;
 435
 436 exit:
 437         while (i--) {
 438                 led_classdev_unregister(&pca963x[i].led_cdev);
 439                 cancel_work_sync(&pca963x[i].work);
 440         }
 441
 442         return err;
 443 }
 444
 445 static int pca963x_remove(struct i2c_client *client)
 446 {
 447         struct pca963x *pca963x = i2c_get_clientdata(client);
 448         int i;
 449
 450         for (i = 0; i < pca963x->chipdef->n_leds; i++) {
 451                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 452                 cancel_work_sync(&pca963x->leds[i].work);
 453         }
 454
 455         return 0;
 456 }
 457
 458 static struct i2c_driver pca963x_driver = {
 459         .driver = {
 460                 .name   = "leds-pca963x",
 461                 .owner  = THIS_MODULE,
 462                 .of_match_table = of_match_ptr(of_pca963x_match),
 463         },
 464         .probe  = pca963x_probe,
 465         .remove = pca963x_remove,
 466         .id_table = pca963x_id,
 467 };
 468
 469 module_i2c_driver(pca963x_driver);
 470
 471 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 472 MODULE_DESCRIPTION("PCA963X LED driver");
 473 MODULE_LICENSE("GPL v2");