drivers/leds/leds-is31fl319x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2015-16 Golden Delicious Computers
   4  *
   5  * Author: Nikolaus Schaller <hns@goldelico.com>
   6  *
   7  * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
   8  * effect LEDs.
   9  */
  10
  11 #include <linux/err.h>
  12 #include <linux/i2c.h>
  13 #include <linux/leds.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_device.h>
  17 #include <linux/regmap.h>
  18 #include <linux/slab.h>
  19 #include <linux/delay.h>
  20 #include <linux/gpio/consumer.h>
  21
  22 /* register numbers */
  23 #define IS31FL319X_SHUTDOWN             0x00
  24 #define IS31FL319X_CTRL1                0x01
  25 #define IS31FL319X_CTRL2                0x02
  26 #define IS31FL319X_CONFIG1              0x03
  27 #define IS31FL319X_CONFIG2              0x04
  28 #define IS31FL319X_RAMP_MODE            0x05
  29 #define IS31FL319X_BREATH_MASK          0x06
  30 #define IS31FL319X_PWM(channel)         (0x07 + channel)
  31 #define IS31FL319X_DATA_UPDATE          0x10
  32 #define IS31FL319X_T0(channel)          (0x11 + channel)
  33 #define IS31FL319X_T123_1               0x1a
  34 #define IS31FL319X_T123_2               0x1b
  35 #define IS31FL319X_T123_3               0x1c
  36 #define IS31FL319X_T4(channel)          (0x1d + channel)
  37 #define IS31FL319X_TIME_UPDATE          0x26
  38 #define IS31FL319X_RESET                0xff
  39
  40 #define IS31FL319X_REG_CNT              (IS31FL319X_RESET + 1)
  41
  42 #define IS31FL319X_MAX_LEDS             9
  43
  44 /* CS (Current Setting) in CONFIG2 register */
  45 #define IS31FL319X_CONFIG2_CS_SHIFT     4
  46 #define IS31FL319X_CONFIG2_CS_MASK      0x7
  47 #define IS31FL319X_CONFIG2_CS_STEP_REF  12
  48
  49 #define IS31FL319X_CURRENT_MIN          ((u32)5000)
  50 #define IS31FL319X_CURRENT_MAX          ((u32)40000)
  51 #define IS31FL319X_CURRENT_STEP         ((u32)5000)
  52 #define IS31FL319X_CURRENT_DEFAULT      ((u32)20000)
  53
  54 /* Audio gain in CONFIG2 register */
  55 #define IS31FL319X_AUDIO_GAIN_DB_MAX    ((u32)21)
  56 #define IS31FL319X_AUDIO_GAIN_DB_STEP   ((u32)3)
  57
  58 /*
  59  * regmap is used as a cache of chip's register space,
  60  * to avoid reading back brightness values from chip,
  61  * which is known to hang.
  62  */
  63 struct is31fl319x_chip {
  64         const struct is31fl319x_chipdef *cdef;
  65         struct i2c_client               *client;
  66         struct gpio_desc                *shutdown_gpio;
  67         struct regmap                   *regmap;
  68         struct mutex                    lock;
  69         u32                             audio_gain_db;
  70
  71         struct is31fl319x_led {
  72                 struct is31fl319x_chip  *chip;
  73                 struct led_classdev     cdev;
  74                 u32                     max_microamp;
  75                 bool                    configured;
  76         } leds[IS31FL319X_MAX_LEDS];
  77 };
  78
  79 struct is31fl319x_chipdef {
  80         int num_leds;
  81 };
  82
  83 static const struct is31fl319x_chipdef is31fl3190_cdef = {
  84         .num_leds = 1,
  85 };
  86
  87 static const struct is31fl319x_chipdef is31fl3193_cdef = {
  88         .num_leds = 3,
  89 };
  90
  91 static const struct is31fl319x_chipdef is31fl3196_cdef = {
  92         .num_leds = 6,
  93 };
  94
  95 static const struct is31fl319x_chipdef is31fl3199_cdef = {
  96         .num_leds = 9,
  97 };
  98
  99 static const struct of_device_id of_is31fl319x_match[] = {
 100         { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
 101         { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
 102         { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
 103         { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
 104         { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
 105         { .compatible = "si-en,sn3199",    .data = &is31fl3199_cdef, },
 106         { }
 107 };
 108 MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
 109
 110 static int is31fl319x_brightness_set(struct led_classdev *cdev,
 111                                      enum led_brightness brightness)
 112 {
 113         struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
 114                                                   cdev);
 115         struct is31fl319x_chip *is31 = led->chip;
 116         int chan = led - is31->leds;
 117         int ret;
 118         int i;
 119         u8 ctrl1 = 0, ctrl2 = 0;
 120
 121         dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);
 122
 123         mutex_lock(&is31->lock);
 124
 125         /* update PWM register */
 126         ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
 127         if (ret < 0)
 128                 goto out;
 129
 130         /* read current brightness of all PWM channels */
 131         for (i = 0; i < is31->cdef->num_leds; i++) {
 132                 unsigned int pwm_value;
 133                 bool on;
 134
 135                 /*
 136                  * since neither cdev nor the chip can provide
 137                  * the current setting, we read from the regmap cache
 138                  */
 139
 140                 ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
 141                 dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
 142                         __func__, i, ret, pwm_value);
 143                 on = ret >= 0 && pwm_value > LED_OFF;
 144
 145                 if (i < 3)
 146                         ctrl1 |= on << i;       /* 0..2 => bit 0..2 */
 147                 else if (i < 6)
 148                         ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
 149                 else
 150                         ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
 151         }
 152
 153         if (ctrl1 > 0 || ctrl2 > 0) {
 154                 dev_dbg(&is31->client->dev, "power up %02x %02x\n",
 155                         ctrl1, ctrl2);
 156                 regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
 157                 regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
 158                 /* update PWMs */
 159                 regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
 160                 /* enable chip from shut down */
 161                 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
 162         } else {
 163                 dev_dbg(&is31->client->dev, "power down\n");
 164                 /* shut down (no need to clear CTRL1/2) */
 165                 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
 166         }
 167
 168 out:
 169         mutex_unlock(&is31->lock);
 170
 171         return ret;
 172 }
 173
 174 static int is31fl319x_parse_child_dt(const struct device *dev,
 175                                      const struct device_node *child,
 176                                      struct is31fl319x_led *led)
 177 {
 178         struct led_classdev *cdev = &led->cdev;
 179         int ret;
 180
 181         if (of_property_read_string(child, "label", &cdev->name))
 182                 cdev->name = child->name;
 183
 184         ret = of_property_read_string(child, "linux,default-trigger",
 185                                       &cdev->default_trigger);
 186         if (ret < 0 && ret != -EINVAL) /* is optional */
 187                 return ret;
 188
 189         led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
 190         ret = of_property_read_u32(child, "led-max-microamp",
 191                                    &led->max_microamp);
 192         if (!ret) {
 193                 if (led->max_microamp < IS31FL319X_CURRENT_MIN)
 194                         return -EINVAL; /* not supported */
 195                 led->max_microamp = min(led->max_microamp,
 196                                           IS31FL319X_CURRENT_MAX);
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int is31fl319x_parse_dt(struct device *dev,
 203                                struct is31fl319x_chip *is31)
 204 {
 205         struct device_node *np = dev_of_node(dev), *child;
 206         int count;
 207         int ret;
 208
 209         if (!np)
 210                 return -ENODEV;
 211
 212         is31->shutdown_gpio = devm_gpiod_get_optional(dev,
 213                                                 "shutdown",
 214                                                 GPIOD_OUT_HIGH);
 215         if (IS_ERR(is31->shutdown_gpio)) {
 216                 ret = PTR_ERR(is31->shutdown_gpio);
 217                 dev_err(dev, "Failed to get shutdown gpio: %d\n", ret);
 218                 return ret;
 219         }
 220
 221         is31->cdef = device_get_match_data(dev);
 222
 223         count = of_get_available_child_count(np);
 224
 225         dev_dbg(dev, "probing with %d leds defined in DT\n", count);
 226
 227         if (!count || count > is31->cdef->num_leds) {
 228                 dev_err(dev, "Number of leds defined must be between 1 and %u\n",
 229                         is31->cdef->num_leds);
 230                 return -ENODEV;
 231         }
 232
 233         for_each_available_child_of_node(np, child) {
 234                 struct is31fl319x_led *led;
 235                 u32 reg;
 236
 237                 ret = of_property_read_u32(child, "reg", &reg);
 238                 if (ret) {
 239                         dev_err(dev, "Failed to read led 'reg' property\n");
 240                         goto put_child_node;
 241                 }
 242
 243                 if (reg < 1 || reg > is31->cdef->num_leds) {
 244                         dev_err(dev, "invalid led reg %u\n", reg);
 245                         ret = -EINVAL;
 246                         goto put_child_node;
 247                 }
 248
 249                 led = &is31->leds[reg - 1];
 250
 251                 if (led->configured) {
 252                         dev_err(dev, "led %u is already configured\n", reg);
 253                         ret = -EINVAL;
 254                         goto put_child_node;
 255                 }
 256
 257                 ret = is31fl319x_parse_child_dt(dev, child, led);
 258                 if (ret) {
 259                         dev_err(dev, "led %u DT parsing failed\n", reg);
 260                         goto put_child_node;
 261                 }
 262
 263                 led->configured = true;
 264         }
 265
 266         is31->audio_gain_db = 0;
 267         ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
 268         if (!ret)
 269                 is31->audio_gain_db = min(is31->audio_gain_db,
 270                                           IS31FL319X_AUDIO_GAIN_DB_MAX);
 271
 272         return 0;
 273
 274 put_child_node:
 275         of_node_put(child);
 276         return ret;
 277 }
 278
 279 static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
 280 { /* we have no readable registers */
 281         return false;
 282 }
 283
 284 static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
 285 { /* volatile registers are not cached */
 286         switch (reg) {
 287         case IS31FL319X_DATA_UPDATE:
 288         case IS31FL319X_TIME_UPDATE:
 289         case IS31FL319X_RESET:
 290                 return true; /* always write-through */
 291         default:
 292                 return false;
 293         }
 294 }
 295
 296 static const struct reg_default is31fl319x_reg_defaults[] = {
 297         { IS31FL319X_CONFIG1, 0x00},
 298         { IS31FL319X_CONFIG2, 0x00},
 299         { IS31FL319X_PWM(0), 0x00},
 300         { IS31FL319X_PWM(1), 0x00},
 301         { IS31FL319X_PWM(2), 0x00},
 302         { IS31FL319X_PWM(3), 0x00},
 303         { IS31FL319X_PWM(4), 0x00},
 304         { IS31FL319X_PWM(5), 0x00},
 305         { IS31FL319X_PWM(6), 0x00},
 306         { IS31FL319X_PWM(7), 0x00},
 307         { IS31FL319X_PWM(8), 0x00},
 308 };
 309
 310 static struct regmap_config regmap_config = {
 311         .reg_bits = 8,
 312         .val_bits = 8,
 313         .max_register = IS31FL319X_REG_CNT,
 314         .cache_type = REGCACHE_FLAT,
 315         .readable_reg = is31fl319x_readable_reg,
 316         .volatile_reg = is31fl319x_volatile_reg,
 317         .reg_defaults = is31fl319x_reg_defaults,
 318         .num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
 319 };
 320
 321 static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
 322 { /* round down to nearest supported value (range check done by caller) */
 323         u32 step = microamp / IS31FL319X_CURRENT_STEP;
 324
 325         return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
 326                 IS31FL319X_CONFIG2_CS_MASK) <<
 327                 IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
 328 }
 329
 330 static inline int is31fl319x_db_to_gain(u32 dezibel)
 331 { /* round down to nearest supported value (range check done by caller) */
 332         return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
 333 }
 334
 335 static int is31fl319x_probe(struct i2c_client *client,
 336                             const struct i2c_device_id *id)
 337 {
 338         struct is31fl319x_chip *is31;
 339         struct device *dev = &client->dev;
 340         int err;
 341         int i = 0;
 342         u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
 343
 344         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 345                 return -EIO;
 346
 347         is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
 348         if (!is31)
 349                 return -ENOMEM;
 350
 351         mutex_init(&is31->lock);
 352
 353         err = is31fl319x_parse_dt(&client->dev, is31);
 354         if (err)
 355                 goto free_mutex;
 356
 357         if (is31->shutdown_gpio) {
 358                 gpiod_direction_output(is31->shutdown_gpio, 0);
 359                 mdelay(5);
 360                 gpiod_direction_output(is31->shutdown_gpio, 1);
 361         }
 362
 363         is31->client = client;
 364         is31->regmap = devm_regmap_init_i2c(client, &regmap_config);
 365         if (IS_ERR(is31->regmap)) {
 366                 dev_err(&client->dev, "failed to allocate register map\n");
 367                 err = PTR_ERR(is31->regmap);
 368                 goto free_mutex;
 369         }
 370
 371         i2c_set_clientdata(client, is31);
 372
 373         /* check for write-reply from chip (we can't read any registers) */
 374         err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
 375         if (err < 0) {
 376                 dev_err(&client->dev, "no response from chip write: err = %d\n",
 377                         err);
 378                 err = -EIO; /* does not answer */
 379                 goto free_mutex;
 380         }
 381
 382         /*
 383          * Kernel conventions require per-LED led-max-microamp property.
 384          * But the chip does not allow to limit individual LEDs.
 385          * So we take minimum from all subnodes for safety of hardware.
 386          */
 387         for (i = 0; i < is31->cdef->num_leds; i++)
 388                 if (is31->leds[i].configured &&
 389                     is31->leds[i].max_microamp < aggregated_led_microamp)
 390                         aggregated_led_microamp = is31->leds[i].max_microamp;
 391
 392         regmap_write(is31->regmap, IS31FL319X_CONFIG2,
 393                      is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
 394                      is31fl319x_db_to_gain(is31->audio_gain_db));
 395
 396         for (i = 0; i < is31->cdef->num_leds; i++) {
 397                 struct is31fl319x_led *led = &is31->leds[i];
 398
 399                 if (!led->configured)
 400                         continue;
 401
 402                 led->chip = is31;
 403                 led->cdev.brightness_set_blocking = is31fl319x_brightness_set;
 404
 405                 err = devm_led_classdev_register(&client->dev, &led->cdev);
 406                 if (err < 0)
 407                         goto free_mutex;
 408         }
 409
 410         return 0;
 411
 412 free_mutex:
 413         mutex_destroy(&is31->lock);
 414         return err;
 415 }
 416
 417 static int is31fl319x_remove(struct i2c_client *client)
 418 {
 419         struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
 420
 421         mutex_destroy(&is31->lock);
 422         return 0;
 423 }
 424
 425 /*
 426  * i2c-core (and modalias) requires that id_table be properly filled,
 427  * even though it is not used for DeviceTree based instantiation.
 428  */
 429 static const struct i2c_device_id is31fl319x_id[] = {
 430         { "is31fl3190" },
 431         { "is31fl3191" },
 432         { "is31fl3193" },
 433         { "is31fl3196" },
 434         { "is31fl3199" },
 435         { "sn3199" },
 436         {},
 437 };
 438 MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
 439
 440 static struct i2c_driver is31fl319x_driver = {
 441         .driver   = {
 442                 .name           = "leds-is31fl319x",
 443                 .of_match_table = of_match_ptr(of_is31fl319x_match),
 444         },
 445         .probe    = is31fl319x_probe,
 446         .remove   = is31fl319x_remove,
 447         .id_table = is31fl319x_id,
 448 };
 449
 450 module_i2c_driver(is31fl319x_driver);
 451
 452 MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
 453 MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
 454 MODULE_DESCRIPTION("IS31FL319X LED driver");
 455 MODULE_LICENSE("GPL v2");