drivers/leds/leds-lm3697.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // TI LM3697 LED chip family driver
   3 // Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
   4
   5 #include <linux/gpio/consumer.h>
   6 #include <linux/i2c.h>
   7 #include <linux/of.h>
   8 #include <linux/of_gpio.h>
   9 #include <linux/regulator/consumer.h>
  10 #include <linux/leds-ti-lmu-common.h>
  11
  12 #define LM3697_REV                      0x0
  13 #define LM3697_RESET                    0x1
  14 #define LM3697_OUTPUT_CONFIG            0x10
  15 #define LM3697_CTRL_A_RAMP              0x11
  16 #define LM3697_CTRL_B_RAMP              0x12
  17 #define LM3697_CTRL_A_B_RT_RAMP         0x13
  18 #define LM3697_CTRL_A_B_RAMP_CFG        0x14
  19 #define LM3697_CTRL_A_B_BRT_CFG         0x16
  20 #define LM3697_CTRL_A_FS_CURR_CFG       0x17
  21 #define LM3697_CTRL_B_FS_CURR_CFG       0x18
  22 #define LM3697_PWM_CFG                  0x1c
  23 #define LM3697_CTRL_A_BRT_LSB           0x20
  24 #define LM3697_CTRL_A_BRT_MSB           0x21
  25 #define LM3697_CTRL_B_BRT_LSB           0x22
  26 #define LM3697_CTRL_B_BRT_MSB           0x23
  27 #define LM3697_CTRL_ENABLE              0x24
  28
  29 #define LM3697_SW_RESET         BIT(0)
  30
  31 #define LM3697_CTRL_A_EN        BIT(0)
  32 #define LM3697_CTRL_B_EN        BIT(1)
  33 #define LM3697_CTRL_A_B_EN      (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN)
  34
  35 #define LM3697_MAX_LED_STRINGS  3
  36
  37 #define LM3697_CONTROL_A        0
  38 #define LM3697_CONTROL_B        1
  39 #define LM3697_MAX_CONTROL_BANKS 2
  40
  41 /**
  42  * struct lm3697_led -
  43  * @hvled_strings: Array of LED strings associated with a control bank
  44  * @label: LED label
  45  * @led_dev: LED class device
  46  * @priv: Pointer to the device struct
  47  * @lmu_data: Register and setting values for common code
  48  * @control_bank: Control bank the LED is associated to. 0 is control bank A
  49  *                 1 is control bank B
  50  */
  51 struct lm3697_led {
  52         u32 hvled_strings[LM3697_MAX_LED_STRINGS];
  53         char label[LED_MAX_NAME_SIZE];
  54         struct led_classdev led_dev;
  55         struct lm3697 *priv;
  56         struct ti_lmu_bank lmu_data;
  57         int control_bank;
  58         int enabled;
  59         int num_leds;
  60 };
  61
  62 /**
  63  * struct lm3697 -
  64  * @enable_gpio: Hardware enable gpio
  65  * @regulator: LED supply regulator pointer
  66  * @client: Pointer to the I2C client
  67  * @regmap: Devices register map
  68  * @dev: Pointer to the devices device struct
  69  * @lock: Lock for reading/writing the device
  70  * @leds: Array of LED strings
  71  */
  72 struct lm3697 {
  73         struct gpio_desc *enable_gpio;
  74         struct regulator *regulator;
  75         struct i2c_client *client;
  76         struct regmap *regmap;
  77         struct device *dev;
  78         struct mutex lock;
  79
  80         int bank_cfg;
  81
  82         struct lm3697_led leds[];
  83 };
  84
  85 static const struct reg_default lm3697_reg_defs[] = {
  86         {LM3697_OUTPUT_CONFIG, 0x6},
  87         {LM3697_CTRL_A_RAMP, 0x0},
  88         {LM3697_CTRL_B_RAMP, 0x0},
  89         {LM3697_CTRL_A_B_RT_RAMP, 0x0},
  90         {LM3697_CTRL_A_B_RAMP_CFG, 0x0},
  91         {LM3697_CTRL_A_B_BRT_CFG, 0x0},
  92         {LM3697_CTRL_A_FS_CURR_CFG, 0x13},
  93         {LM3697_CTRL_B_FS_CURR_CFG, 0x13},
  94         {LM3697_PWM_CFG, 0xc},
  95         {LM3697_CTRL_A_BRT_LSB, 0x0},
  96         {LM3697_CTRL_A_BRT_MSB, 0x0},
  97         {LM3697_CTRL_B_BRT_LSB, 0x0},
  98         {LM3697_CTRL_B_BRT_MSB, 0x0},
  99         {LM3697_CTRL_ENABLE, 0x0},
 100 };
 101
 102 static const struct regmap_config lm3697_regmap_config = {
 103         .reg_bits = 8,
 104         .val_bits = 8,
 105
 106         .max_register = LM3697_CTRL_ENABLE,
 107         .reg_defaults = lm3697_reg_defs,
 108         .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),
 109         .cache_type = REGCACHE_FLAT,
 110 };
 111
 112 static int lm3697_brightness_set(struct led_classdev *led_cdev,
 113                                 enum led_brightness brt_val)
 114 {
 115         struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,
 116                                               led_dev);
 117         int ctrl_en_val = (1 << led->control_bank);
 118         int ret;
 119
 120         mutex_lock(&led->priv->lock);
 121
 122         if (brt_val == LED_OFF) {
 123                 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,
 124                                          ctrl_en_val, ~ctrl_en_val);
 125                 if (ret) {
 126                         dev_err(&led->priv->client->dev, "Cannot write ctrl register\n");
 127                         goto brightness_out;
 128                 }
 129
 130                 led->enabled = LED_OFF;
 131         } else {
 132                 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
 133                 if (ret) {
 134                         dev_err(&led->priv->client->dev,
 135                                 "Cannot write brightness\n");
 136                         goto brightness_out;
 137                 }
 138
 139                 if (!led->enabled) {
 140                         ret = regmap_update_bits(led->priv->regmap,
 141                                                  LM3697_CTRL_ENABLE,
 142                                                  ctrl_en_val, ctrl_en_val);
 143                         if (ret) {
 144                                 dev_err(&led->priv->client->dev,
 145                                         "Cannot enable the device\n");
 146                                 goto brightness_out;
 147                         }
 148
 149                         led->enabled = brt_val;
 150                 }
 151         }
 152
 153 brightness_out:
 154         mutex_unlock(&led->priv->lock);
 155         return ret;
 156 }
 157
 158 static int lm3697_init(struct lm3697 *priv)
 159 {
 160         struct lm3697_led *led;
 161         int i, ret;
 162
 163         if (priv->enable_gpio) {
 164                 gpiod_direction_output(priv->enable_gpio, 1);
 165         } else {
 166                 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);
 167                 if (ret) {
 168                         dev_err(&priv->client->dev, "Cannot reset the device\n");
 169                         goto out;
 170                 }
 171         }
 172
 173         ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);
 174         if (ret) {
 175                 dev_err(&priv->client->dev, "Cannot write ctrl enable\n");
 176                 goto out;
 177         }
 178
 179         ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);
 180         if (ret)
 181                 dev_err(&priv->client->dev, "Cannot write OUTPUT config\n");
 182
 183         for (i = 0; i < LM3697_MAX_CONTROL_BANKS; i++) {
 184                 led = &priv->leds[i];
 185                 ret = ti_lmu_common_set_ramp(&led->lmu_data);
 186                 if (ret)
 187                         dev_err(&priv->client->dev, "Setting the ramp rate failed\n");
 188         }
 189 out:
 190         return ret;
 191 }
 192
 193 static int lm3697_probe_dt(struct lm3697 *priv)
 194 {
 195         struct fwnode_handle *child = NULL;
 196         struct lm3697_led *led;
 197         const char *name;
 198         int control_bank;
 199         size_t i = 0;
 200         int ret = -EINVAL;
 201         int j;
 202
 203         priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev,
 204                                                    "enable", GPIOD_OUT_LOW);
 205         if (IS_ERR(priv->enable_gpio)) {
 206                 ret = PTR_ERR(priv->enable_gpio);
 207                 dev_err(&priv->client->dev, "Failed to get enable gpio: %d\n",
 208                         ret);
 209                 return ret;
 210         }
 211
 212         priv->regulator = devm_regulator_get(&priv->client->dev, "vled");
 213         if (IS_ERR(priv->regulator))
 214                 priv->regulator = NULL;
 215
 216         device_for_each_child_node(priv->dev, child) {
 217                 ret = fwnode_property_read_u32(child, "reg", &control_bank);
 218                 if (ret) {
 219                         dev_err(&priv->client->dev, "reg property missing\n");
 220                         fwnode_handle_put(child);
 221                         goto child_out;
 222                 }
 223
 224                 if (control_bank > LM3697_CONTROL_B) {
 225                         dev_err(&priv->client->dev, "reg property is invalid\n");
 226                         ret = -EINVAL;
 227                         fwnode_handle_put(child);
 228                         goto child_out;
 229                 }
 230
 231                 led = &priv->leds[i];
 232
 233                 ret = ti_lmu_common_get_brt_res(&priv->client->dev,
 234                                                 child, &led->lmu_data);
 235                 if (ret)
 236                         dev_warn(&priv->client->dev, "brightness resolution property missing\n");
 237
 238                 led->control_bank = control_bank;
 239                 led->lmu_data.regmap = priv->regmap;
 240                 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
 241                                                  control_bank;
 242                 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
 243                                                    led->control_bank * 2;
 244                 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
 245                                                    led->control_bank * 2;
 246
 247                 led->num_leds = fwnode_property_count_u32(child, "led-sources");
 248                 if (led->num_leds > LM3697_MAX_LED_STRINGS) {
 249                         dev_err(&priv->client->dev, "Too many LED strings defined\n");
 250                         continue;
 251                 }
 252
 253                 ret = fwnode_property_read_u32_array(child, "led-sources",
 254                                                     led->hvled_strings,
 255                                                     led->num_leds);
 256                 if (ret) {
 257                         dev_err(&priv->client->dev, "led-sources property missing\n");
 258                         fwnode_handle_put(child);
 259                         goto child_out;
 260                 }
 261
 262                 for (j = 0; j < led->num_leds; j++)
 263                         priv->bank_cfg |=
 264                                 (led->control_bank << led->hvled_strings[j]);
 265
 266                 ret = ti_lmu_common_get_ramp_params(&priv->client->dev,
 267                                                     child, &led->lmu_data);
 268                 if (ret)
 269                         dev_warn(&priv->client->dev, "runtime-ramp properties missing\n");
 270
 271                 fwnode_property_read_string(child, "linux,default-trigger",
 272                                             &led->led_dev.default_trigger);
 273
 274                 ret = fwnode_property_read_string(child, "label", &name);
 275                 if (ret)
 276                         snprintf(led->label, sizeof(led->label),
 277                                 "%s::", priv->client->name);
 278                 else
 279                         snprintf(led->label, sizeof(led->label),
 280                                  "%s:%s", priv->client->name, name);
 281
 282                 led->priv = priv;
 283                 led->led_dev.name = led->label;
 284                 led->led_dev.max_brightness = led->lmu_data.max_brightness;
 285                 led->led_dev.brightness_set_blocking = lm3697_brightness_set;
 286
 287                 ret = devm_led_classdev_register(priv->dev, &led->led_dev);
 288                 if (ret) {
 289                         dev_err(&priv->client->dev, "led register err: %d\n",
 290                                 ret);
 291                         fwnode_handle_put(child);
 292                         goto child_out;
 293                 }
 294
 295                 i++;
 296         }
 297
 298 child_out:
 299         return ret;
 300 }
 301
 302 static int lm3697_probe(struct i2c_client *client,
 303                         const struct i2c_device_id *id)
 304 {
 305         struct lm3697 *led;
 306         int count;
 307         int ret;
 308
 309         count = device_get_child_node_count(&client->dev);
 310         if (!count) {
 311                 dev_err(&client->dev, "LEDs are not defined in device tree!");
 312                 return -ENODEV;
 313         }
 314
 315         led = devm_kzalloc(&client->dev, struct_size(led, leds, count),
 316                            GFP_KERNEL);
 317         if (!led)
 318                 return -ENOMEM;
 319
 320         mutex_init(&led->lock);
 321         i2c_set_clientdata(client, led);
 322
 323         led->client = client;
 324         led->dev = &client->dev;
 325         led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config);
 326         if (IS_ERR(led->regmap)) {
 327                 ret = PTR_ERR(led->regmap);
 328                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 329                         ret);
 330                 return ret;
 331         }
 332
 333         ret = lm3697_probe_dt(led);
 334         if (ret)
 335                 return ret;
 336
 337         return lm3697_init(led);
 338 }
 339
 340 static int lm3697_remove(struct i2c_client *client)
 341 {
 342         struct lm3697 *led = i2c_get_clientdata(client);
 343         int ret;
 344
 345         ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,
 346                                  LM3697_CTRL_A_B_EN, 0);
 347         if (ret) {
 348                 dev_err(&led->client->dev, "Failed to disable the device\n");
 349                 return ret;
 350         }
 351
 352         if (led->enable_gpio)
 353                 gpiod_direction_output(led->enable_gpio, 0);
 354
 355         if (led->regulator) {
 356                 ret = regulator_disable(led->regulator);
 357                 if (ret)
 358                         dev_err(&led->client->dev,
 359                                 "Failed to disable regulator\n");
 360         }
 361
 362         mutex_destroy(&led->lock);
 363
 364         return 0;
 365 }
 366
 367 static const struct i2c_device_id lm3697_id[] = {
 368         { "lm3697", 0 },
 369         { }
 370 };
 371 MODULE_DEVICE_TABLE(i2c, lm3697_id);
 372
 373 static const struct of_device_id of_lm3697_leds_match[] = {
 374         { .compatible = "ti,lm3697", },
 375         {},
 376 };
 377 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
 378
 379 static struct i2c_driver lm3697_driver = {
 380         .driver = {
 381                 .name   = "lm3697",
 382                 .of_match_table = of_lm3697_leds_match,
 383         },
 384         .probe          = lm3697_probe,
 385         .remove         = lm3697_remove,
 386         .id_table       = lm3697_id,
 387 };
 388 module_i2c_driver(lm3697_driver);
 389
 390 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
 391 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 392 MODULE_LICENSE("GPL v2");