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