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