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_bulk_data regulators[2];
  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_bulk_disable(ARRAY_SIZE(chip->regulators),
 110                                      chip->regulators);
 111         if (ret) {
 112                 dev_err(&chip->client->dev,
 113                         "Failed to disable regulators: %d\n", ret);
 114                 return;
 115         }
 116
 117         chip->enabled = false;
 118 }
 119
 120 static int aw2013_chip_enable(struct aw2013 *chip)
 121 {
 122         int ret;
 123
 124         if (chip->enabled)
 125                 return 0;
 126
 127         ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators),
 128                                     chip->regulators);
 129         if (ret) {
 130                 dev_err(&chip->client->dev,
 131                         "Failed to enable regulators: %d\n", ret);
 132                 return ret;
 133         }
 134         chip->enabled = true;
 135
 136         ret = aw2013_chip_init(chip);
 137         if (ret)
 138                 aw2013_chip_disable(chip);
 139
 140         return ret;
 141 }
 142
 143 static bool aw2013_chip_in_use(struct aw2013 *chip)
 144 {
 145         int i;
 146
 147         for (i = 0; i < chip->num_leds; i++)
 148                 if (chip->leds[i].cdev.brightness)
 149                         return true;
 150
 151         return false;
 152 }
 153
 154 static int aw2013_brightness_set(struct led_classdev *cdev,
 155                                  enum led_brightness brightness)
 156 {
 157         struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
 158         int ret, num;
 159
 160         mutex_lock(&led->chip->mutex);
 161
 162         if (aw2013_chip_in_use(led->chip)) {
 163                 ret = aw2013_chip_enable(led->chip);
 164                 if (ret)
 165                         goto error;
 166         }
 167
 168         num = led->num;
 169
 170         ret = regmap_write(led->chip->regmap, AW2013_REG_PWM(num), brightness);
 171         if (ret)
 172                 goto error;
 173
 174         if (brightness) {
 175                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 176                                          AW2013_LCTR_LE(num), 0xFF);
 177         } else {
 178                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 179                                          AW2013_LCTR_LE(num), 0);
 180                 if (ret)
 181                         goto error;
 182                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 183                                          AW2013_LCFG_MD, 0);
 184         }
 185         if (ret)
 186                 goto error;
 187
 188         if (!aw2013_chip_in_use(led->chip))
 189                 aw2013_chip_disable(led->chip);
 190
 191 error:
 192         mutex_unlock(&led->chip->mutex);
 193
 194         return ret;
 195 }
 196
 197 static int aw2013_blink_set(struct led_classdev *cdev,
 198                             unsigned long *delay_on, unsigned long *delay_off)
 199 {
 200         struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);
 201         int ret, num = led->num;
 202         unsigned long off = 0, on = 0;
 203
 204         /* If no blink specified, default to 1 Hz. */
 205         if (!*delay_off && !*delay_on) {
 206                 *delay_off = 500;
 207                 *delay_on = 500;
 208         }
 209
 210         if (!led->cdev.brightness) {
 211                 led->cdev.brightness = LED_FULL;
 212                 ret = aw2013_brightness_set(&led->cdev, led->cdev.brightness);
 213                 if (ret)
 214                         return ret;
 215         }
 216
 217         /* Never on - just set to off */
 218         if (!*delay_on) {
 219                 led->cdev.brightness = LED_OFF;
 220                 return aw2013_brightness_set(&led->cdev, LED_OFF);
 221         }
 222
 223         mutex_lock(&led->chip->mutex);
 224
 225         /* Never off - brightness is already set, disable blinking */
 226         if (!*delay_off) {
 227                 ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 228                                          AW2013_LCFG_MD, 0);
 229                 goto out;
 230         }
 231
 232         /* Convert into values the HW will understand. */
 233         off = min(5, ilog2((*delay_off - 1) / AW2013_TIME_STEP) + 1);
 234         on = min(7, ilog2((*delay_on - 1) / AW2013_TIME_STEP) + 1);
 235
 236         *delay_off = BIT(off) * AW2013_TIME_STEP;
 237         *delay_on = BIT(on) * AW2013_TIME_STEP;
 238
 239         /* Set timings */
 240         ret = regmap_write(led->chip->regmap,
 241                            AW2013_LEDT0(num), AW2013_LEDT0_T2(on));
 242         if (ret)
 243                 goto out;
 244         ret = regmap_write(led->chip->regmap,
 245                            AW2013_LEDT1(num), AW2013_LEDT1_T4(off));
 246         if (ret)
 247                 goto out;
 248
 249         /* Finally, enable the LED */
 250         ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),
 251                                  AW2013_LCFG_MD, 0xFF);
 252         if (ret)
 253                 goto out;
 254
 255         ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,
 256                                  AW2013_LCTR_LE(num), 0xFF);
 257
 258 out:
 259         mutex_unlock(&led->chip->mutex);
 260
 261         return ret;
 262 }
 263
 264 static int aw2013_probe_dt(struct aw2013 *chip)
 265 {
 266         struct device_node *np = dev_of_node(&chip->client->dev);
 267         int count, ret = 0, i = 0;
 268         struct aw2013_led *led;
 269
 270         count = of_get_available_child_count(np);
 271         if (!count || count > AW2013_MAX_LEDS)
 272                 return -EINVAL;
 273
 274         regmap_write(chip->regmap, AW2013_RSTR, AW2013_RSTR_RESET);
 275
 276         for_each_available_child_of_node_scoped(np, child) {
 277                 struct led_init_data init_data = {};
 278                 u32 source;
 279                 u32 imax;
 280
 281                 ret = of_property_read_u32(child, "reg", &source);
 282                 if (ret != 0 || source >= AW2013_MAX_LEDS) {
 283                         dev_err(&chip->client->dev,
 284                                 "Couldn't read LED address: %d\n", ret);
 285                         count--;
 286                         continue;
 287                 }
 288
 289                 led = &chip->leds[i];
 290                 led->num = source;
 291                 led->chip = chip;
 292                 init_data.fwnode = of_fwnode_handle(child);
 293
 294                 if (!of_property_read_u32(child, "led-max-microamp", &imax)) {
 295                         led->imax = min_t(u32, imax / 5000, 3);
 296                 } else {
 297                         led->imax = 1; // 5mA
 298                         dev_info(&chip->client->dev,
 299                                  "DT property led-max-microamp is missing\n");
 300                 }
 301
 302                 led->cdev.brightness_set_blocking = aw2013_brightness_set;
 303                 led->cdev.blink_set = aw2013_blink_set;
 304
 305                 ret = devm_led_classdev_register_ext(&chip->client->dev,
 306                                                      &led->cdev, &init_data);
 307                 if (ret < 0)
 308                         return ret;
 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 void aw2013_chip_disable_action(void *data)
 322 {
 323         aw2013_chip_disable(data);
 324 }
 325
 326 static const struct regmap_config aw2013_regmap_config = {
 327         .reg_bits = 8,
 328         .val_bits = 8,
 329         .max_register = AW2013_REG_MAX,
 330 };
 331
 332 static int aw2013_probe(struct i2c_client *client)
 333 {
 334         struct aw2013 *chip;
 335         int ret;
 336         unsigned int chipid;
 337
 338         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 339         if (!chip)
 340                 return -ENOMEM;
 341
 342         ret = devm_mutex_init(&client->dev, &chip->mutex);
 343         if (ret)
 344                 return ret;
 345
 346         mutex_lock(&chip->mutex);
 347
 348         chip->client = client;
 349         i2c_set_clientdata(client, chip);
 350
 351         chip->regmap = devm_regmap_init_i2c(client, &aw2013_regmap_config);
 352         if (IS_ERR(chip->regmap)) {
 353                 ret = PTR_ERR(chip->regmap);
 354                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 355                         ret);
 356                 goto error;
 357         }
 358
 359         chip->regulators[0].supply = "vcc";
 360         chip->regulators[1].supply = "vio";
 361         ret = devm_regulator_bulk_get(&client->dev,
 362                                       ARRAY_SIZE(chip->regulators),
 363                                       chip->regulators);
 364         if (ret < 0) {
 365                 if (ret != -EPROBE_DEFER)
 366                         dev_err(&client->dev,
 367                                 "Failed to request regulators: %d\n", ret);
 368                 goto error;
 369         }
 370
 371         ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators),
 372                                     chip->regulators);
 373         if (ret) {
 374                 dev_err(&client->dev,
 375                         "Failed to enable regulators: %d\n", ret);
 376                 goto error;
 377         }
 378
 379         ret = regmap_read(chip->regmap, AW2013_RSTR, &chipid);
 380         if (ret) {
 381                 dev_err(&client->dev, "Failed to read chip ID: %d\n",
 382                         ret);
 383                 goto error_reg;
 384         }
 385
 386         if (chipid != AW2013_RSTR_CHIP_ID) {
 387                 dev_err(&client->dev, "Chip reported wrong ID: %x\n",
 388                         chipid);
 389                 ret = -ENODEV;
 390                 goto error_reg;
 391         }
 392
 393         ret = devm_add_action(&client->dev, aw2013_chip_disable_action, chip);
 394         if (ret)
 395                 goto error_reg;
 396
 397         ret = aw2013_probe_dt(chip);
 398         if (ret < 0)
 399                 goto error_reg;
 400
 401         ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators),
 402                                      chip->regulators);
 403         if (ret) {
 404                 dev_err(&client->dev,
 405                         "Failed to disable regulators: %d\n", ret);
 406                 goto error;
 407         }
 408
 409         mutex_unlock(&chip->mutex);
 410
 411         return 0;
 412
 413 error_reg:
 414         regulator_bulk_disable(ARRAY_SIZE(chip->regulators),
 415                                chip->regulators);
 416
 417 error:
 418         mutex_unlock(&chip->mutex);
 419         return ret;
 420 }
 421
 422 static const struct of_device_id aw2013_match_table[] = {
 423         { .compatible = "awinic,aw2013", },
 424         { /* sentinel */ },
 425 };
 426
 427 MODULE_DEVICE_TABLE(of, aw2013_match_table);
 428
 429 static struct i2c_driver aw2013_driver = {
 430         .driver = {
 431                 .name = "leds-aw2013",
 432                 .of_match_table = aw2013_match_table,
 433         },
 434         .probe = aw2013_probe,
 435 };
 436
 437 module_i2c_driver(aw2013_driver);
 438
 439 MODULE_AUTHOR("Nikita Travkin <nikitos.tr@gmail.com>");
 440 MODULE_DESCRIPTION("AW2013 LED driver");
 441 MODULE_LICENSE("GPL v2");