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/slab.h>
  36 #include <linux/of.h>
  37 #include <linux/platform_data/leds-pca963x.h>
  38
  39 /* LED select registers determine the source that drives LED outputs */
  40 #define PCA963X_LED_OFF         0x0     /* LED driver off */
  41 #define PCA963X_LED_ON          0x1     /* LED driver on */
  42 #define PCA963X_LED_PWM         0x2     /* Controlled through PWM */
  43 #define PCA963X_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  44
  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 };
  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         [pca9635] = {
  78                 .grppwm         = 0x12,
  79                 .grpfreq        = 0x13,
  80                 .ledout_base    = 0x14,
  81                 .n_leds         = 16,
  82         },
  83 };
  84
  85 /* Total blink period in milliseconds */
  86 #define PCA963X_BLINK_PERIOD_MIN        42
  87 #define PCA963X_BLINK_PERIOD_MAX        10667
  88
  89 static const struct i2c_device_id pca963x_id[] = {
  90         { "pca9632", pca9633 },
  91         { "pca9633", pca9633 },
  92         { "pca9634", pca9634 },
  93         { "pca9635", pca9635 },
  94         { }
  95 };
  96 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  97
  98 struct pca963x_led;
  99
 100 struct pca963x {
 101         struct pca963x_chipdef *chipdef;
 102         struct mutex mutex;
 103         struct i2c_client *client;
 104         struct pca963x_led *leds;
 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         mutex_lock(&pca963x->chip->mutex);
 127         ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 128         switch (brightness) {
 129         case LED_FULL:
 130                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 131                         ledout_addr,
 132                         (ledout & ~mask) | (PCA963X_LED_ON << shift));
 133                 break;
 134         case LED_OFF:
 135                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 136                         ledout_addr, ledout & ~mask);
 137                 break;
 138         default:
 139                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 140                         PCA963X_PWM_BASE + pca963x->led_num,
 141                         brightness);
 142                 if (ret < 0)
 143                         goto unlock;
 144                 ret = i2c_smbus_write_byte_data(pca963x->chip->client,
 145                         ledout_addr,
 146                         (ledout & ~mask) | (PCA963X_LED_PWM << shift));
 147                 break;
 148         }
 149 unlock:
 150         mutex_unlock(&pca963x->chip->mutex);
 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_led_set(struct led_classdev *led_cdev,
 183         enum led_brightness value)
 184 {
 185         struct pca963x_led *pca963x;
 186
 187         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 188
 189         return pca963x_brightness(pca963x, value);
 190 }
 191
 192 static int pca963x_blink_set(struct led_classdev *led_cdev,
 193                 unsigned long *delay_on, unsigned long *delay_off)
 194 {
 195         struct pca963x_led *pca963x;
 196         unsigned long time_on, time_off, period;
 197         u8 gdc, gfrq;
 198
 199         pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
 200
 201         time_on = *delay_on;
 202         time_off = *delay_off;
 203
 204         /* If both zero, pick reasonable defaults of 500ms each */
 205         if (!time_on && !time_off) {
 206                 time_on = 500;
 207                 time_off = 500;
 208         }
 209
 210         period = time_on + time_off;
 211
 212         /* If period not supported by hardware, default to someting sane. */
 213         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 214             (period > PCA963X_BLINK_PERIOD_MAX)) {
 215                 time_on = 500;
 216                 time_off = 500;
 217                 period = time_on + time_off;
 218         }
 219
 220         /*
 221          * From manual: duty cycle = (GDC / 256) ->
 222          *      (time_on / period) = (GDC / 256) ->
 223          *              GDC = ((time_on * 256) / period)
 224          */
 225         gdc = (time_on * 256) / period;
 226
 227         /*
 228          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 229          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 230          *              GFRQ = ((period * 24 / 1000) - 1)
 231          */
 232         gfrq = (period * 24 / 1000) - 1;
 233
 234         pca963x->gdc = gdc;
 235         pca963x->gfrq = gfrq;
 236
 237         pca963x_blink(pca963x);
 238
 239         *delay_on = time_on;
 240         *delay_off = time_off;
 241
 242         return 0;
 243 }
 244
 245 #if IS_ENABLED(CONFIG_OF)
 246 static struct pca963x_platform_data *
 247 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 248 {
 249         struct device_node *np = client->dev.of_node, *child;
 250         struct pca963x_platform_data *pdata;
 251         struct led_info *pca963x_leds;
 252         int count;
 253
 254         count = of_get_child_count(np);
 255         if (!count || count > chip->n_leds)
 256                 return ERR_PTR(-ENODEV);
 257
 258         pca963x_leds = devm_kzalloc(&client->dev,
 259                         sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
 260         if (!pca963x_leds)
 261                 return ERR_PTR(-ENOMEM);
 262
 263         for_each_child_of_node(np, child) {
 264                 struct led_info led = {};
 265                 u32 reg;
 266                 int res;
 267
 268                 res = of_property_read_u32(child, "reg", &reg);
 269                 if ((res != 0) || (reg >= chip->n_leds))
 270                         continue;
 271                 led.name =
 272                         of_get_property(child, "label", NULL) ? : child->name;
 273                 led.default_trigger =
 274                         of_get_property(child, "linux,default-trigger", NULL);
 275                 pca963x_leds[reg] = led;
 276         }
 277         pdata = devm_kzalloc(&client->dev,
 278                              sizeof(struct pca963x_platform_data), GFP_KERNEL);
 279         if (!pdata)
 280                 return ERR_PTR(-ENOMEM);
 281
 282         pdata->leds.leds = pca963x_leds;
 283         pdata->leds.num_leds = chip->n_leds;
 284
 285         /* default to open-drain unless totem pole (push-pull) is specified */
 286         if (of_property_read_bool(np, "nxp,totem-pole"))
 287                 pdata->outdrv = PCA963X_TOTEM_POLE;
 288         else
 289                 pdata->outdrv = PCA963X_OPEN_DRAIN;
 290
 291         /* default to software blinking unless hardware blinking is specified */
 292         if (of_property_read_bool(np, "nxp,hw-blink"))
 293                 pdata->blink_type = PCA963X_HW_BLINK;
 294         else
 295                 pdata->blink_type = PCA963X_SW_BLINK;
 296
 297         return pdata;
 298 }
 299
 300 static const struct of_device_id of_pca963x_match[] = {
 301         { .compatible = "nxp,pca9632", },
 302         { .compatible = "nxp,pca9633", },
 303         { .compatible = "nxp,pca9634", },
 304         { .compatible = "nxp,pca9635", },
 305         {},
 306 };
 307 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 308 #else
 309 static struct pca963x_platform_data *
 310 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 311 {
 312         return ERR_PTR(-ENODEV);
 313 }
 314 #endif
 315
 316 static int pca963x_probe(struct i2c_client *client,
 317                                         const struct i2c_device_id *id)
 318 {
 319         struct pca963x *pca963x_chip;
 320         struct pca963x_led *pca963x;
 321         struct pca963x_platform_data *pdata;
 322         struct pca963x_chipdef *chip;
 323         int i, err;
 324
 325         chip = &pca963x_chipdefs[id->driver_data];
 326         pdata = dev_get_platdata(&client->dev);
 327
 328         if (!pdata) {
 329                 pdata = pca963x_dt_init(client, chip);
 330                 if (IS_ERR(pdata)) {
 331                         dev_warn(&client->dev, "could not parse configuration\n");
 332                         pdata = NULL;
 333                 }
 334         }
 335
 336         if (pdata && (pdata->leds.num_leds < 1 ||
 337                                  pdata->leds.num_leds > chip->n_leds)) {
 338                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 339                                                                 chip->n_leds);
 340                 return -EINVAL;
 341         }
 342
 343         pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 344                                                                 GFP_KERNEL);
 345         if (!pca963x_chip)
 346                 return -ENOMEM;
 347         pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
 348                                                                 GFP_KERNEL);
 349         if (!pca963x)
 350                 return -ENOMEM;
 351
 352         i2c_set_clientdata(client, pca963x_chip);
 353
 354         mutex_init(&pca963x_chip->mutex);
 355         pca963x_chip->chipdef = chip;
 356         pca963x_chip->client = client;
 357         pca963x_chip->leds = pca963x;
 358
 359         /* Turn off LEDs by default*/
 360         for (i = 0; i < chip->n_leds / 4; i++)
 361                 i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
 362
 363         for (i = 0; i < chip->n_leds; i++) {
 364                 pca963x[i].led_num = i;
 365                 pca963x[i].chip = pca963x_chip;
 366
 367                 /* Platform data can specify LED names and default triggers */
 368                 if (pdata && i < pdata->leds.num_leds) {
 369                         if (pdata->leds.leds[i].name)
 370                                 snprintf(pca963x[i].name,
 371                                          sizeof(pca963x[i].name), "pca963x:%s",
 372                                          pdata->leds.leds[i].name);
 373                         if (pdata->leds.leds[i].default_trigger)
 374                                 pca963x[i].led_cdev.default_trigger =
 375                                         pdata->leds.leds[i].default_trigger;
 376                 }
 377                 if (!pdata || i >= pdata->leds.num_leds ||
 378                                                 !pdata->leds.leds[i].name)
 379                         snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 380                                  "pca963x:%d:%.2x:%d", client->adapter->nr,
 381                                  client->addr, i);
 382
 383                 pca963x[i].led_cdev.name = pca963x[i].name;
 384                 pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
 385
 386                 if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 387                         pca963x[i].led_cdev.blink_set = pca963x_blink_set;
 388
 389                 err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 390                 if (err < 0)
 391                         goto exit;
 392         }
 393
 394         /* Disable LED all-call address and set normal mode */
 395         i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);
 396
 397         if (pdata) {
 398                 /* Configure output: open-drain or totem pole (push-pull) */
 399                 if (pdata->outdrv == PCA963X_OPEN_DRAIN)
 400                         i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);
 401                 else
 402                         i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x05);
 403         }
 404
 405         return 0;
 406
 407 exit:
 408         while (i--)
 409                 led_classdev_unregister(&pca963x[i].led_cdev);
 410
 411         return err;
 412 }
 413
 414 static int pca963x_remove(struct i2c_client *client)
 415 {
 416         struct pca963x *pca963x = i2c_get_clientdata(client);
 417         int i;
 418
 419         for (i = 0; i < pca963x->chipdef->n_leds; i++)
 420                 led_classdev_unregister(&pca963x->leds[i].led_cdev);
 421
 422         return 0;
 423 }
 424
 425 static struct i2c_driver pca963x_driver = {
 426         .driver = {
 427                 .name   = "leds-pca963x",
 428                 .of_match_table = of_match_ptr(of_pca963x_match),
 429         },
 430         .probe  = pca963x_probe,
 431         .remove = pca963x_remove,
 432         .id_table = pca963x_id,
 433 };
 434
 435 module_i2c_driver(pca963x_driver);
 436
 437 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 438 MODULE_DESCRIPTION("PCA963X LED driver");
 439 MODULE_LICENSE("GPL v2");