drivers/leds/leds-aw2013.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 // Driver for Awinic AW2013 3-channel LED driver
   3
   4 #include <linux/i2c.h>
   5 #include <linux/leds.h>
   6 #include <linux/module.h>
   7 #include <linux/regulator/consumer.h>
   8 #include <linux/mutex.h>
   9 #include <linux/of.h>
  10 #include <linux/regmap.h>
  11
  12 #define AW2013_MAX_LEDS 3
  13
  14 /* Reset and ID register */
  15 #define AW2013_RSTR 0x00
  16 #define AW2013_RSTR_RESET 0x55
  17 #define AW2013_RSTR_CHIP_ID 0x33
  18
  19 /* Global control register */
  20 #define AW2013_GCR 0x01
  21 #define AW2013_GCR_ENABLE BIT(0)
  22
  23 /* LED channel enable register */
  24 #define AW2013_LCTR 0x30
  25 #define AW2013_LCTR_LE(x) BIT((x))
  26
  27 /* LED channel control registers */
  28 #define AW2013_LCFG(x) (0x31 + (x))
  29 #define AW2013_LCFG_IMAX_MASK (BIT(0) | BIT(1)) // Should be 0-3
  30 #define AW2013_LCFG_MD BIT(4)
  31 #define AW2013_LCFG_FI BIT(5)
  32 #define AW2013_LCFG_FO BIT(6)
  33
  34 /* LED channel PWM registers */
  35 #define AW2013_REG_PWM(x) (0x34 + (x))
  36
  37 /* LED channel timing registers */
  38 #define AW2013_LEDT0(x) (0x37 + (x) * 3)
  39 #define AW2013_LEDT0_T1(x) ((x) << 4) // Should be 0-7
  40 #define AW2013_LEDT0_T2(x) (x) // Should be 0-5
  41
  42 #define AW2013_LEDT1(x) (0x38 + (x) * 3)
  43 #define AW2013_LEDT1_T3(x) ((x) << 4) // Should be 0-7
  44 #define AW2013_LEDT1_T4(x) (x) // Should be 0-7
  45
  46 #define AW2013_LEDT2(x) (0x39 + (x) * 3)
  47 #define AW2013_LEDT2_T0(x) ((x) << 4) // Should be 0-8
  48 #define AW2013_LEDT2_REPEAT(x) (x) // Should be 0-15
  49
  50 #define AW2013_REG_MAX 0x77
  51
  52 #define AW2013_TIME_STEP 130 /* ms */
  53
  54 struct aw2013;
  55
  56 struct aw2013_led {
  57         struct aw2013 *chip;
  58         struct led_classdev cdev;
  59         u32 num;
  60         unsigned int imax;
  61 };
  62
  63 struct aw2013 {
  64         struct mutex mutex; /* held when writing to registers */
  65         struct regulator *vcc_regulator;
  66         struct i2c_client *client;
  67         struct aw2013_led leds[AW2013_MAX_LEDS];
  68         struct regmap *regmap;
  69         int num_leds;
  70         bool enabled;
  71 };
  72
  73 static int aw2013_chip_init(struct aw2013 *chip)
  74 {
  75         int i, ret;
  76
  77         ret = regmap_write(chip->regmap, AW2013_GCR, AW2013_GCR_ENABLE);
  78         if (ret) {
  79                 dev_err(&chip->client->dev, "Failed to enable the chip: %d\n",
  80                         ret);
  81                 return ret;
  82         }
  83
  84         for (i = 0; i < chip->num_leds; i++) {
  85                 ret = regmap_update_bits(chip->regmap,
  86                                          AW2013_LCFG(chip->leds[i].num),
  87                                          AW2013_LCFG_IMAX_MASK,
  88                                          chip->leds[i].imax);
  89                 if (ret) {
  90                         dev_err(&chip->client->dev,
  91                                 "Failed to set maximum current for led %d: %d\n",
  92                                 chip->leds[i].num, ret);
  93                         return ret;
  94                 }
  95         }
  96
  97         return ret;
  98 }
  99
 100 static void aw2013_chip_disable(struct aw2013 *chip)
 101 {
 102         int ret;
 103
 104         if (!chip->enabled)
 105                 return;
 106
 107         regmap_write(chip->regmap, AW2013_GCR, 0);
 108
 109         ret = regulator_disable(chip->vcc_regulator);
 110         if (ret) {
 111                 dev_err(&chip->client->dev,
 112                         "Failed to disable regulator: %d\n", ret);
 113                 return;
 114         }
 115
 116         chip->enabled = false;
 117 }
 118
 119 static int aw2013_chip_enable(struct aw2013 *chip)
 120 {
 121         int ret;
 122
 123         if (chip->enabled)
 124                 return 0;
 125
 126         ret = regulator_enable(chip->vcc_regulator);
 127         if (ret) {
 128                 dev_err(&chip->client->dev,
 129                         "Failed to enable regulator: %d\n", ret);
 130                 return ret;
 131         }
 132         chip->enabled = true;
 133
 134         ret = aw2013_chip_init(chip);
 135         if (ret)
 136                 aw2013_chip_disable(chip);
 137
 138         return ret;
 139 }
 140
 141 static bool aw2013_chip_in_use(struct aw2013 *chip)
 142 {
 143         int i;
 144
 145         for (i = 0; i < chip->num_leds; i++)
 146                 if (chip->leds[i].cdev.brightness)
 147                         return true;
 148
 149         return false;
 150 }
 151
 152 static int aw2013_brightness_set(struct led_classdev *cdev,
 153                                  enum led_brightness brightness)
 154 {
 155         struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
 156         int ret, num;
 157
 158         mutex_lock(&led->chip->mutex);
 159
 160         if (aw2013_chip_in_use(led->chip)) {
 161                 ret = aw2013_chip_enable(led->chip);
 162                 if (ret)
 163                         goto error;
 164         }
 165
 166         num = led->num;
 167
 168         ret = regmap_write(led->chip->regmap, AW2013_REG_PWM(num), brightness);
 169         if (ret)
 170                 goto error;
 171
 172         if (brightness) {
 173                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 174                                          AW2013_LCTR_LE(num), 0xFF);
 175         } else {
 176                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 177                                          AW2013_LCTR_LE(num), 0);
 178                 if (ret)
 179                         goto error;
 180                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 181                                          AW2013_LCFG_MD, 0);
 182         }
 183         if (ret)
 184                 goto error;
 185
 186         if (!aw2013_chip_in_use(led->chip))
 187                 aw2013_chip_disable(led->chip);
 188
 189 error:
 190         mutex_unlock(&led->chip->mutex);
 191
 192         return ret;
 193 }
 194
 195 static int aw2013_blink_set(struct led_classdev *cdev,
 196                             unsigned long *delay_on, unsigned long *delay_off)
 197 {
 198         struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
 199         int ret, num = led->num;
 200         unsigned long off = 0, on = 0;
 201
 202         /* If no blink specified, default to 1 Hz. */
 203         if (!*delay_off && !*delay_on) {
 204                 *delay_off = 500;
 205                 *delay_on = 500;
 206         }
 207
 208         if (!led->cdev.brightness) {
 209                 led->cdev.brightness = LED_FULL;
 210                 ret = aw2013_brightness_set(&led->cdev, led->cdev.brightness);
 211                 if (ret)
 212                         return ret;
 213         }
 214
 215         /* Never on - just set to off */
 216         if (!*delay_on) {
 217                 led->cdev.brightness = LED_OFF;
 218                 return aw2013_brightness_set(&led->cdev, LED_OFF);
 219         }
 220
 221         mutex_lock(&led->chip->mutex);
 222
 223         /* Never off - brightness is already set, disable blinking */
 224         if (!*delay_off) {
 225                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 226                                          AW2013_LCFG_MD, 0);
 227                 goto out;
 228         }
 229
 230         /* Convert into values the HW will understand. */
 231         off = min(5, ilog2((*delay_off - 1) / AW2013_TIME_STEP) + 1);
 232         on = min(7, ilog2((*delay_on - 1) / AW2013_TIME_STEP) + 1);
 233
 234         *delay_off = BIT(off) * AW2013_TIME_STEP;
 235         *delay_on = BIT(on) * AW2013_TIME_STEP;
 236
 237         /* Set timings */
 238         ret = regmap_write(led->chip->regmap,
 239                            AW2013_LEDT0(num), AW2013_LEDT0_T2(on));
 240         if (ret)
 241                 goto out;
 242         ret = regmap_write(led->chip->regmap,
 243                            AW2013_LEDT1(num), AW2013_LEDT1_T4(off));
 244         if (ret)
 245                 goto out;
 246
 247         /* Finally, enable the LED */
 248         ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 249                                  AW2013_LCFG_MD, 0xFF);
 250         if (ret)
 251                 goto out;
 252
 253         ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 254                                  AW2013_LCTR_LE(num), 0xFF);
 255
 256 out:
 257         mutex_unlock(&led->chip->mutex);
 258
 259         return ret;
 260 }
 261
 262 static int aw2013_probe_dt(struct aw2013 *chip)
 263 {
 264         struct device_node *np = dev_of_node(&chip->client->dev), *child;
 265         int count, ret = 0, i = 0;
 266         struct aw2013_led *led;
 267
 268         count = of_get_available_child_count(np);
 269         if (!count || count > AW2013_MAX_LEDS)
 270                 return -EINVAL;
 271
 272         regmap_write(chip->regmap, AW2013_RSTR, AW2013_RSTR_RESET);
 273
 274         for_each_available_child_of_node(np, child) {
 275                 struct led_init_data init_data = {};
 276                 u32 source;
 277                 u32 imax;
 278
 279                 ret = of_property_read_u32(child, "reg", &source);
 280                 if (ret != 0 || source >= AW2013_MAX_LEDS) {
 281                         dev_err(&chip->client->dev,
 282                                 "Couldn't read LED address: %d\n", ret);
 283                         count--;
 284                         continue;
 285                 }
 286
 287                 led = &chip->leds[i];
 288                 led->num = source;
 289                 led->chip = chip;
 290                 init_data.fwnode = of_fwnode_handle(child);
 291
 292                 if (!of_property_read_u32(child, "led-max-microamp", &imax)) {
 293                         led->imax = min_t(u32, imax / 5000, 3);
 294                 } else {
 295                         led->imax = 1; // 5mA
 296                         dev_info(&chip->client->dev,
 297                                  "DT property led-max-microamp is missing\n");
 298                 }
 299
 300                 led->cdev.brightness_set_blocking = aw2013_brightness_set;
 301                 led->cdev.blink_set = aw2013_blink_set;
 302
 303                 ret = devm_led_classdev_register_ext(&chip->client->dev,
 304                                                      &led->cdev, &init_data);
 305                 if (ret < 0) {
 306                         of_node_put(child);
 307                         return ret;
 308                 }
 309
 310                 i++;
 311         }
 312
 313         if (!count)
 314                 return -EINVAL;
 315
 316         chip->num_leds = i;
 317
 318         return 0;
 319 }
 320
 321 static const struct regmap_config aw2013_regmap_config = {
 322         .reg_bits = 8,
 323         .val_bits = 8,
 324         .max_register = AW2013_REG_MAX,
 325 };
 326
 327 static int aw2013_probe(struct i2c_client *client)
 328 {
 329         struct aw2013 *chip;
 330         int ret;
 331         unsigned int chipid;
 332
 333         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 334         if (!chip)
 335                 return -ENOMEM;
 336
 337         mutex_init(&chip->mutex);
 338         mutex_lock(&chip->mutex);
 339
 340         chip->client = client;
 341         i2c_set_clientdata(client, chip);
 342
 343         chip->regmap = devm_regmap_init_i2c(client, &aw2013_regmap_config);
 344         if (IS_ERR(chip->regmap)) {
 345                 ret = PTR_ERR(chip->regmap);
 346                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 347                         ret);
 348                 goto error;
 349         }
 350
 351         chip->vcc_regulator = devm_regulator_get(&client->dev, "vcc");
 352         ret = PTR_ERR_OR_ZERO(chip->vcc_regulator);
 353         if (ret) {
 354                 if (ret != -EPROBE_DEFER)
 355                         dev_err(&client->dev,
 356                                 "Failed to request regulator: %d\n", ret);
 357                 goto error;
 358         }
 359
 360         ret = regulator_enable(chip->vcc_regulator);
 361         if (ret) {
 362                 dev_err(&client->dev,
 363                         "Failed to enable regulator: %d\n", ret);
 364                 goto error;
 365         }
 366
 367         ret = regmap_read(chip->regmap, AW2013_RSTR, &chipid);
 368         if (ret) {
 369                 dev_err(&client->dev, "Failed to read chip ID: %d\n",
 370                         ret);
 371                 goto error_reg;
 372         }
 373
 374         if (chipid != AW2013_RSTR_CHIP_ID) {
 375                 dev_err(&client->dev, "Chip reported wrong ID: %x\n",
 376                         chipid);
 377                 ret = -ENODEV;
 378                 goto error_reg;
 379         }
 380
 381         ret = aw2013_probe_dt(chip);
 382         if (ret < 0)
 383                 goto error_reg;
 384
 385         ret = regulator_disable(chip->vcc_regulator);
 386         if (ret) {
 387                 dev_err(&client->dev,
 388                         "Failed to disable regulator: %d\n", ret);
 389                 goto error;
 390         }
 391
 392         mutex_unlock(&chip->mutex);
 393
 394         return 0;
 395
 396 error_reg:
 397         regulator_disable(chip->vcc_regulator);
 398
 399 error:
 400         mutex_destroy(&chip->mutex);
 401         return ret;
 402 }
 403
 404 static int aw2013_remove(struct i2c_client *client)
 405 {
 406         struct aw2013 *chip = i2c_get_clientdata(client);
 407
 408         aw2013_chip_disable(chip);
 409
 410         mutex_destroy(&chip->mutex);
 411
 412         return 0;
 413 }
 414
 415 static const struct of_device_id aw2013_match_table[] = {
 416         { .compatible = "awinic,aw2013", },
 417         { /* sentinel */ },
 418 };
 419
 420 MODULE_DEVICE_TABLE(of, aw2013_match_table);
 421
 422 static struct i2c_driver aw2013_driver = {
 423         .driver = {
 424                 .name = "leds-aw2013",
 425                 .of_match_table = of_match_ptr(aw2013_match_table),
 426         },
 427         .probe_new = aw2013_probe,
 428         .remove = aw2013_remove,
 429 };
 430
 431 module_i2c_driver(aw2013_driver);
 432
 433 MODULE_AUTHOR("Nikita Travkin <nikitos.tr@gmail.com>");
 434 MODULE_DESCRIPTION("AW2013 LED driver");
 435 MODULE_LICENSE("GPL v2");