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 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 };
  56
  57 struct pca963x_chipdef {
  58         u8                      grppwm;
  59         u8                      grpfreq;
  60         u8                      ledout_base;
  61         int                     n_leds;
  62 };
  63
  64 static struct pca963x_chipdef pca963x_chipdefs[] = {
  65         [pca9633] = {
  66                 .grppwm         = 0x6,
  67                 .grpfreq        = 0x7,
  68                 .ledout_base    = 0x8,
  69                 .n_leds         = 4,
  70         },
  71         [pca9634] = {
  72                 .grppwm         = 0xa,
  73                 .grpfreq        = 0xb,
  74                 .ledout_base    = 0xc,
  75                 .n_leds         = 8,
  76         },
  77 };
  78
  79 /* Total blink period in milliseconds */
  80 #define PCA963X_BLINK_PERIOD_MIN        42
  81 #define PCA963X_BLINK_PERIOD_MAX        10667
  82
  83 static const struct i2c_device_id pca963x_id[] = {
  84         { "pca9632", pca9633 },
  85         { "pca9633", pca9633 },
  86         { "pca9634", pca9634 },
  87         { }
  88 };
  89 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  90
  91 enum pca963x_cmd {
  92         BRIGHTNESS_SET,
  93         BLINK_SET,
  94 };
  95
  96 struct pca963x_led;
  97
  98 struct pca963x {
  99         struct pca963x_chipdef *chipdef;
 100         struct mutex mutex;
 101         struct i2c_client *client;
 102         struct pca963x_led *leds;
 103 };
 104
 105 struct pca963x_led {
 106         struct pca963x *chip;
 107         struct work_struct work;
 108         enum led_brightness brightness;
 109         struct led_classdev led_cdev;
 110         int led_num; /* 0 .. 7 potentially */
 111         enum pca963x_cmd cmd;
 112         char name[32];
 113         u8 gdc;
 114         u8 gfrq;
 115 };
 116
 117 static void pca963x_brightness_work(struct pca963x_led *pca963x)
 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
 125         mutex_lock(&pca963x->chip->mutex);
 126         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 127         switch (pca963x->brightness) {
 128         case LED_FULL:
 129                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 130                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 131                 break;
 132         case LED_OFF:
 133                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 134                         ledout & ~mask);
 135                 break;
 136         default:
 137                 i2c_smbus_write_byte_data(pca963x->chip->client,
 138                         PCA963X_PWM_BASE + pca963x->led_num,
 139                         pca963x->brightness);
 140                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 141                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 142                 break;
 143         }
 144         mutex_unlock(&pca963x->chip->mutex);
 145 }
 146
 147 static void pca963x_blink_work(struct pca963x_led *pca963x)
 148 {
 149         u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 150                 (pca963x->led_num / 4);
 151         u8 ledout;
 152         u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 153                                                         PCA963X_MODE2);
 154         int shift = 2 * (pca963x->led_num % 4);
 155         u8 mask = 0x3 << shift;
 156
 157         i2c_smbus_write_byte_data(pca963x->chip->client,
 158                         pca963x->chip->chipdef->grppwm, pca963x->gdc);
 159
 160         i2c_smbus_write_byte_data(pca963x->chip->client,
 161                         pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
 162
 163         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 164                 i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 165                         mode2 | PCA963X_MODE2_DMBLNK);
 166
 167         mutex_lock(&pca963x->chip->mutex);
 168         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 169         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 170                 i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 171                         (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 172         mutex_unlock(&pca963x->chip->mutex);
 173 }
 174
 175 static void pca963x_work(struct work_struct *work)
 176 {
 177         struct pca963x_led *pca963x = container_of(work,
 178                 struct pca963x_led, work);
 179
 180         switch (pca963x->cmd) {
 181         case BRIGHTNESS_SET:
 182                 pca963x_brightness_work(pca963x);
 183                 break;
 184         case BLINK_SET:
 185                 pca963x_blink_work(pca963x);
 186                 break;
 187         }
 188 }
 189
 190 static void pca963x_led_set(struct led_classdev *led_cdev,
 191         enum led_brightness value)
 192 {
 193         struct pca963x_led *pca963x;
 194
 195         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 196
 197         pca963x->cmd = BRIGHTNESS_SET;
 198         pca963x->brightness = value;
 199
 200         /*
 201          * Must use workqueue for the actual I/O since I2C operations
 202          * can sleep.
 203          */
 204         schedule_work(&pca963x->work);
 205 }
 206
 207 static int pca963x_blink_set(struct led_classdev *led_cdev,
 208                 unsigned long *delay_on, unsigned long *delay_off)
 209 {
 210         struct pca963x_led *pca963x;
 211         unsigned long time_on, time_off, period;
 212         u8 gdc, gfrq;
 213
 214         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 215
 216         time_on = *delay_on;
 217         time_off = *delay_off;
 218
 219         /* If both zero, pick reasonable defaults of 500ms each */
 220         if (!time_on && !time_off) {
 221                 time_on = 500;
 222                 time_off = 500;
 223         }
 224
 225         period = time_on + time_off;
 226
 227         /* If period not supported by hardware, default to someting sane. */
 228         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 229             (period > PCA963X_BLINK_PERIOD_MAX)) {
 230                 time_on = 500;
 231                 time_off = 500;
 232                 period = time_on + time_off;
 233         }
 234
 235         /*
 236          * From manual: duty cycle = (GDC / 256) ->
 237          *      (time_on / period) = (GDC / 256) ->
 238          *              GDC = ((time_on * 256) / period)
 239          */
 240         gdc = (time_on * 256) / period;
 241
 242         /*
 243          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 244          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 245          *              GFRQ = ((period * 24 / 1000) - 1)
 246          */
 247         gfrq = (period * 24 / 1000) - 1;
 248
 249         pca963x->cmd = BLINK_SET;
 250         pca963x->gdc = gdc;
 251         pca963x->gfrq = gfrq;
 252
 253         /*
 254          * Must use workqueue for the actual I/O since I2C operations
 255          * can sleep.
 256          */
 257         schedule_work(&pca963x->work);
 258
 259         *delay_on = time_on;
 260         *delay_off = time_off;
 261
 262         return 0;
 263 }
 264
 265 #if IS_ENABLED(CONFIG_OF)
 266 static struct pca963x_platform_data *
 267 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 268 {
 269         struct device_node *np = client->dev.of_node, *child;
 270         struct pca963x_platform_data *pdata;
 271         struct led_info *pca963x_leds;
 272         int count;
 273
 274         count = of_get_child_count(np);
 275         if (!count || count > chip->n_leds)
 276                 return ERR_PTR(-ENODEV);
 277
 278         pca963x_leds = devm_kzalloc(&client->dev,
 279                         sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
 280         if (!pca963x_leds)
 281                 return ERR_PTR(-ENOMEM);
 282
 283         for_each_child_of_node(np, child) {
 284                 struct led_info led;
 285                 u32 reg;
 286                 int res;
 287
 288                 res = of_property_read_u32(child, "reg", &reg);
 289                 if ((res != 0) || (reg >= chip->n_leds))
 290                         continue;
 291                 led.name =
 292                         of_get_property(child, "label", NULL) ? : child->name;
 293                 led.default_trigger =
 294                         of_get_property(child, "linux,default-trigger", NULL);
 295                 pca963x_leds[reg] = led;
 296         }
 297         pdata = devm_kzalloc(&client->dev,
 298                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 299         if (!pdata)
 300                 return ERR_PTR(-ENOMEM);
 301
 302         pdata->leds.leds = pca963x_leds;
 303         pdata->leds.num_leds = chip->n_leds;
 304
 305         /* default to open-drain unless totem pole (push-pull) is specified */
 306         if (of_property_read_bool(np, "nxp,totem-pole"))
 307                 pdata->outdrv = PCA963X_TOTEM_POLE;
 308         else
 309                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 310
 311         /* default to software blinking unless hardware blinking is specified */
 312         if (of_property_read_bool(np, "nxp,hw-blink"))
 313                 pdata->blink_type = PCA963X_HW_BLINK;
 314         else
 315                 pdata->blink_type = PCA963X_SW_BLINK;
 316
 317         return pdata;
 318 }
 319
 320 static const struct of_device_id of_pca963x_match[] = {
 321         { .compatible = "nxp,pca9632", },
 322         { .compatible = "nxp,pca9633", },
 323         { .compatible = "nxp,pca9634", },
 324         {},
 325 };
 326 #else
 327 static struct pca963x_platform_data *
 328 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 329 {
 330         return ERR_PTR(-ENODEV);
 331 }
 332 #endif
 333
 334 static int pca963x_probe(struct i2c_client *client,
 335                                         const struct i2c_device_id *id)
 336 {
 337         struct pca963x *pca963x_chip;
 338         struct pca963x_led *pca963x;
 339         struct pca963x_platform_data *pdata;
 340         struct pca963x_chipdef *chip;
 341         int i, err;
 342
 343         chip = &pca963x_chipdefs[id->driver_data];
 344         pdata = dev_get_platdata(&client->dev);
 345
 346         if (!pdata) {
 347                 pdata = pca963x_dt_init(client, chip);
 348                 if (IS_ERR(pdata)) {
 349                         dev_warn(&client->dev, "could not parse configuration\n");
 350                         pdata = NULL;
 351                 }
 352         }
 353
 354         if (pdata && (pdata->leds.num_leds < 1 ||
 355                                  pdata->leds.num_leds > chip->n_leds)) {
 356                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 357                                                                 chip->n_leds);
 358                 return -EINVAL;
 359         }
 360
 361         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 362                                                                 GFP_KERNEL);
 363         if (!pca963x_chip)
 364                 return -ENOMEM;
 365         pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
 366                                                                 GFP_KERNEL);
 367         if (!pca963x)
 368                 return -ENOMEM;
 369
 370         i2c_set_clientdata(client, pca963x_chip);
 371
 372         mutex_init(&pca963x_chip->mutex);
 373         pca963x_chip->chipdef = chip;
 374         pca963x_chip->client = client;
 375         pca963x_chip->leds = pca963x;
 376
 377         /* Turn off LEDs by default*/
 378         i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
 379         if (chip->n_leds > 4)
 380                 i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);
 381
 382         for (i = 0; i < chip->n_leds; i++) {
 383                 pca963x[i].led_num = i;
 384                 pca963x[i].chip = pca963x_chip;
 385
 386                 /* Platform data can specify LED names and default triggers */
 387                 if (pdata && i < pdata->leds.num_leds) {
 388                         if (pdata->leds.leds[i].name)
 389                                 snprintf(pca963x[i].name,
 390                                          sizeof(pca963x[i].name), "pca963x:%s",
 391                                          pdata->leds.leds[i].name);
 392                         if (pdata->leds.leds[i].default_trigger)
 393                                 pca963x[i].led_cdev.default_trigger =
 394                                         pdata->leds.leds[i].default_trigger;
 395                 }
 396                 if (!pdata || i >= pdata->leds.num_leds ||
 397                                                 !pdata->leds.leds[i].name)
 398                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 399                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 400                                  client->addr, i);
 401
 402                 pca963x[i].led_cdev.name = pca963x[i].name;
 403                 pca963x[i].led_cdev.brightness_set = pca963x_led_set;
 404
 405                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 406                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 407
 408                 INIT_WORK(&pca963x[i].work, pca963x_work);
 409
 410                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 411                 if (err < 0)
 412                         goto exit;
 413         }
 414
 415         /* Disable LED all-call address and set normal mode */
 416         i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);
 417
 418         /* Configure output: open-drain or totem pole (push-pull) */
 419         if (pdata && pdata->outdrv == PCA963X_OPEN_DRAIN)
 420                 i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);
 421
 422         return 0;
 423
 424 exit:
 425         while (i--) {
 426                 led_classdev_unregister(&pca963x[i].led_cdev);
 427                 cancel_work_sync(&pca963x[i].work);
 428         }
 429
 430         return err;
 431 }
 432
 433 static int pca963x_remove(struct i2c_client *client)
 434 {
 435         struct pca963x *pca963x = i2c_get_clientdata(client);
 436         int i;
 437
 438         for (i = 0; i < pca963x->chipdef->n_leds; i++) {
 439                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 440                 cancel_work_sync(&pca963x->leds[i].work);
 441         }
 442
 443         return 0;
 444 }
 445
 446 static struct i2c_driver pca963x_driver = {
 447         .driver = {
 448                 .name   = "leds-pca963x",
 449                 .owner  = THIS_MODULE,
 450                 .of_match_table = of_match_ptr(of_pca963x_match),
 451         },
 452         .probe  = pca963x_probe,
 453         .remove = pca963x_remove,
 454         .id_table = pca963x_id,
 455 };
 456
 457 module_i2c_driver(pca963x_driver);
 458
 459 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 460 MODULE_DESCRIPTION("PCA963X LED driver");
 461 MODULE_LICENSE("GPL v2");