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