drivers/leds/leds-pca9633.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 'PCA9633_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-pca9633.h>
  39
  40 /* LED select registers determine the source that drives LED outputs */
  41 #define PCA9633_LED_OFF         0x0     /* LED driver off */
  42 #define PCA9633_LED_ON          0x1     /* LED driver on */
  43 #define PCA9633_LED_PWM         0x2     /* Controlled through PWM */
  44 #define PCA9633_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  45
  46 #define PCA9633_MODE2_DMBLNK    0x20    /* Enable blinking */
  47
  48 #define PCA9633_MODE1           0x00
  49 #define PCA9633_MODE2           0x01
  50 #define PCA9633_PWM_BASE        0x02
  51
  52 enum pca9633_type {
  53         pca9633,
  54         pca9634,
  55 };
  56
  57 struct pca9633_chipdef {
  58         u8                      grppwm;
  59         u8                      grpfreq;
  60         u8                      ledout_base;
  61         int                     n_leds;
  62 };
  63
  64 static struct pca9633_chipdef pca9633_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 PCA9632_BLINK_PERIOD_MIN        42
  81 #define PCA9632_BLINK_PERIOD_MAX        10667
  82
  83 static const struct i2c_device_id pca9633_id[] = {
  84         { "pca9632", pca9633 },
  85         { "pca9633", pca9633 },
  86         { "pca9634", pca9634 },
  87         { }
  88 };
  89 MODULE_DEVICE_TABLE(i2c, pca9633_id);
  90
  91 enum pca9633_cmd {
  92         BRIGHTNESS_SET,
  93         BLINK_SET,
  94 };
  95
  96 struct pca9633_led {
  97         struct i2c_client *client;
  98         struct pca9633_chipdef *chipdef;
  99         struct work_struct work;
 100         enum led_brightness brightness;
 101         struct led_classdev led_cdev;
 102         int led_num; /* 0 .. 7 potentially */
 103         enum pca9633_cmd cmd;
 104         char name[32];
 105         u8 gdc;
 106         u8 gfrq;
 107 };
 108
 109 static void pca9633_brightness_work(struct pca9633_led *pca9633)
 110 {
 111         u8 ledout_addr = pca9633->chipdef->ledout_base + (pca9633->led_num / 4);
 112         u8 ledout;
 113         int shift = 2 * (pca9633->led_num % 4);
 114         u8 mask = 0x3 << shift;
 115
 116         ledout = i2c_smbus_read_byte_data(pca9633->client, ledout_addr);
 117         switch (pca9633->brightness) {
 118         case LED_FULL:
 119                 i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
 120                         (ledout & ~mask) | (PCA9633_LED_ON << shift));
 121                 break;
 122         case LED_OFF:
 123                 i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
 124                         ledout & ~mask);
 125                 break;
 126         default:
 127                 i2c_smbus_write_byte_data(pca9633->client,
 128                         PCA9633_PWM_BASE + pca9633->led_num,
 129                         pca9633->brightness);
 130                 i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
 131                         (ledout & ~mask) | (PCA9633_LED_PWM << shift));
 132                 break;
 133         }
 134 }
 135
 136 static void pca9633_blink_work(struct pca9633_led *pca9633)
 137 {
 138         u8 ledout_addr = pca9633->chipdef->ledout_base + (pca9633->led_num / 4);
 139         u8 ledout = i2c_smbus_read_byte_data(pca9633->client, ledout_addr);
 140         u8 mode2 = i2c_smbus_read_byte_data(pca9633->client, PCA9633_MODE2);
 141         int shift = 2 * (pca9633->led_num % 4);
 142         u8 mask = 0x3 << shift;
 143
 144         i2c_smbus_write_byte_data(pca9633->client, pca9633->chipdef->grppwm,
 145                 pca9633->gdc);
 146
 147         i2c_smbus_write_byte_data(pca9633->client, pca9633->chipdef->grpfreq,
 148                 pca9633->gfrq);
 149
 150         if (!(mode2 & PCA9633_MODE2_DMBLNK))
 151                 i2c_smbus_write_byte_data(pca9633->client, PCA9633_MODE2,
 152                         mode2 | PCA9633_MODE2_DMBLNK);
 153
 154         if ((ledout & mask) != (PCA9633_LED_GRP_PWM << shift))
 155                 i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
 156                         (ledout & ~mask) | (PCA9633_LED_GRP_PWM << shift));
 157 }
 158
 159 static void pca9633_work(struct work_struct *work)
 160 {
 161         struct pca9633_led *pca9633 = container_of(work,
 162                 struct pca9633_led, work);
 163
 164         switch (pca9633->cmd) {
 165         case BRIGHTNESS_SET:
 166                 pca9633_brightness_work(pca9633);
 167                 break;
 168         case BLINK_SET:
 169                 pca9633_blink_work(pca9633);
 170                 break;
 171         }
 172 }
 173
 174 static void pca9633_led_set(struct led_classdev *led_cdev,
 175         enum led_brightness value)
 176 {
 177         struct pca9633_led *pca9633;
 178
 179         pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
 180
 181         pca9633->cmd = BRIGHTNESS_SET;
 182         pca9633->brightness = value;
 183
 184         /*
 185          * Must use workqueue for the actual I/O since I2C operations
 186          * can sleep.
 187          */
 188         schedule_work(&pca9633->work);
 189 }
 190
 191 static int pca9633_blink_set(struct led_classdev *led_cdev,
 192                 unsigned long *delay_on, unsigned long *delay_off)
 193 {
 194         struct pca9633_led *pca9633;
 195         unsigned long time_on, time_off, period;
 196         u8 gdc, gfrq;
 197
 198         pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
 199
 200         time_on = *delay_on;
 201         time_off = *delay_off;
 202
 203         /* If both zero, pick reasonable defaults of 500ms each */
 204         if (!time_on && !time_off) {
 205                 time_on = 500;
 206                 time_off = 500;
 207         }
 208
 209         period = time_on + time_off;
 210
 211         /* If period not supported by hardware, default to someting sane. */
 212         if ((period < PCA9632_BLINK_PERIOD_MIN) ||
 213             (period > PCA9632_BLINK_PERIOD_MAX)) {
 214                 time_on = 500;
 215                 time_off = 500;
 216                 period = time_on + time_off;
 217         }
 218
 219         /*
 220          * From manual: duty cycle = (GDC / 256) ->
 221          *      (time_on / period) = (GDC / 256) ->
 222          *              GDC = ((time_on * 256) / period)
 223          */
 224         gdc = (time_on * 256) / period;
 225
 226         /*
 227          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 228          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 229          *              GFRQ = ((period * 24 / 1000) - 1)
 230          */
 231         gfrq = (period * 24 / 1000) - 1;
 232
 233         pca9633->cmd = BLINK_SET;
 234         pca9633->gdc = gdc;
 235         pca9633->gfrq = gfrq;
 236
 237         /*
 238          * Must use workqueue for the actual I/O since I2C operations
 239          * can sleep.
 240          */
 241         schedule_work(&pca9633->work);
 242
 243         *delay_on = time_on;
 244         *delay_off = time_off;
 245
 246         return 0;
 247 }
 248
 249 #if IS_ENABLED(CONFIG_OF)
 250 static struct pca9633_platform_data *
 251 pca9633_dt_init(struct i2c_client *client, struct pca9633_chipdef *chip)
 252 {
 253         struct device_node *np = client->dev.of_node, *child;
 254         struct pca9633_platform_data *pdata;
 255         struct led_info *pca9633_leds;
 256         int count;
 257
 258         count = of_get_child_count(np);
 259         if (!count || count > chip->n_leds)
 260                 return ERR_PTR(-ENODEV);
 261
 262         pca9633_leds = devm_kzalloc(&client->dev,
 263                         sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
 264         if (!pca9633_leds)
 265                 return ERR_PTR(-ENOMEM);
 266
 267         for_each_child_of_node(np, child) {
 268                 struct led_info led;
 269                 u32 reg;
 270                 int res;
 271
 272                 led.name =
 273                         of_get_property(child, "label", NULL) ? : child->name;
 274                 led.default_trigger =
 275                         of_get_property(child, "linux,default-trigger", NULL);
 276                 res = of_property_read_u32(child, "reg", &reg);
 277                 if (res != 0)
 278                         continue;
 279                 pca9633_leds[reg] = led;
 280         }
 281         pdata = devm_kzalloc(&client->dev,
 282                              sizeof(struct pca9633_platform_data), GFP_KERNEL);
 283         if (!pdata)
 284                 return ERR_PTR(-ENOMEM);
 285
 286         pdata->leds.leds = pca9633_leds;
 287         pdata->leds.num_leds = count;
 288
 289         /* default to open-drain unless totem pole (push-pull) is specified */
 290         if (of_property_read_bool(np, "nxp,totem-pole"))
 291                 pdata->outdrv = PCA9633_TOTEM_POLE;
 292         else
 293                 pdata->outdrv = PCA9633_OPEN_DRAIN;
 294
 295         /* default to software blinking unless hardware blinking is specified */
 296         if (of_property_read_bool(np, "nxp,hw-blink"))
 297                 pdata->blink_type = PCA9633_HW_BLINK;
 298         else
 299                 pdata->blink_type = PCA9633_SW_BLINK;
 300
 301         return pdata;
 302 }
 303
 304 static const struct of_device_id of_pca9633_match[] = {
 305         { .compatible = "nxp,pca9632", },
 306         { .compatible = "nxp,pca9633", },
 307         { .compatible = "nxp,pca9634", },
 308         {},
 309 };
 310 #else
 311 static struct pca9633_platform_data *
 312 pca9633_dt_init(struct i2c_client *client, struct pca9633_chipdef *chip)
 313 {
 314         return ERR_PTR(-ENODEV);
 315 }
 316 #endif
 317
 318 static int pca9633_probe(struct i2c_client *client,
 319                                         const struct i2c_device_id *id)
 320 {
 321         struct pca9633_led *pca9633;
 322         struct pca9633_platform_data *pdata;
 323         struct pca9633_chipdef *chip;
 324         int i, err;
 325
 326         chip = &pca9633_chipdefs[id->driver_data];
 327         pdata = dev_get_platdata(&client->dev);
 328
 329         if (!pdata) {
 330                 pdata = pca9633_dt_init(client, chip);
 331                 if (IS_ERR(pdata)) {
 332                         dev_warn(&client->dev, "could not parse configuration\n");
 333                         pdata = NULL;
 334                 }
 335         }
 336
 337         if (pdata && (pdata->leds.num_leds < 1 ||
 338                                  pdata->leds.num_leds > chip->n_leds)) {
 339                 dev_err(&client->dev, "board info must claim 1-%d LEDs",
 340                                                                 chip->n_leds);
 341                 return -EINVAL;
 342         }
 343
 344         pca9633 = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca9633),
 345                                                                 GFP_KERNEL);
 346         if (!pca9633)
 347                 return -ENOMEM;
 348
 349         i2c_set_clientdata(client, pca9633);
 350
 351         for (i = 0; i < chip->n_leds; i++) {
 352                 pca9633[i].client = client;
 353                 pca9633[i].led_num = i;
 354                 pca9633[i].chipdef = chip;
 355
 356                 /* Platform data can specify LED names and default triggers */
 357                 if (pdata && i < pdata->leds.num_leds) {
 358                         if (pdata->leds.leds[i].name)
 359                                 snprintf(pca9633[i].name,
 360                                          sizeof(pca9633[i].name), "pca9633:%s",
 361                                          pdata->leds.leds[i].name);
 362                         if (pdata->leds.leds[i].default_trigger)
 363                                 pca9633[i].led_cdev.default_trigger =
 364                                         pdata->leds.leds[i].default_trigger;
 365                 }
 366                 if (!pdata || i >= pdata->leds.num_leds ||
 367                                                 !pdata->leds.leds[i].name)
 368                         snprintf(pca9633[i].name, sizeof(pca9633[i].name),
 369                                  "pca9633:%d:%.2x:%d", client->adapter->nr,
 370                                  client->addr, i);
 371
 372                 pca9633[i].led_cdev.name = pca9633[i].name;
 373                 pca9633[i].led_cdev.brightness_set = pca9633_led_set;
 374
 375                 if (pdata && pdata->blink_type == PCA9633_HW_BLINK)
 376                         pca9633[i].led_cdev.blink_set = pca9633_blink_set;
 377
 378                 INIT_WORK(&pca9633[i].work, pca9633_work);
 379
 380                 err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
 381                 if (err < 0)
 382                         goto exit;
 383         }
 384
 385         /* Disable LED all-call address and set normal mode */
 386         i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00);
 387
 388         /* Configure output: open-drain or totem pole (push-pull) */
 389         if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
 390                 i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01);
 391
 392         /* Turn off LEDs */
 393         i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
 394         if (chip->n_leds > 4)
 395                 i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);
 396
 397         return 0;
 398
 399 exit:
 400         while (i--) {
 401                 led_classdev_unregister(&pca9633[i].led_cdev);
 402                 cancel_work_sync(&pca9633[i].work);
 403         }
 404
 405         return err;
 406 }
 407
 408 static int pca9633_remove(struct i2c_client *client)
 409 {
 410         struct pca9633_led *pca9633 = i2c_get_clientdata(client);
 411         int i;
 412
 413         for (i = 0; i < pca9633->chipdef->n_leds; i++)
 414                 if (pca9633[i].client != NULL) {
 415                         led_classdev_unregister(&pca9633[i].led_cdev);
 416                         cancel_work_sync(&pca9633[i].work);
 417                 }
 418
 419         return 0;
 420 }
 421
 422 static struct i2c_driver pca9633_driver = {
 423         .driver = {
 424                 .name   = "leds-pca9633",
 425                 .owner  = THIS_MODULE,
 426                 .of_match_table = of_match_ptr(of_pca9633_match),
 427         },
 428         .probe  = pca9633_probe,
 429         .remove = pca9633_remove,
 430         .id_table = pca9633_id,
 431 };
 432
 433 module_i2c_driver(pca9633_driver);
 434
 435 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 436 MODULE_DESCRIPTION("PCA9633 LED driver");
 437 MODULE_LICENSE("GPL v2");