drivers/leds/leds-lm3530.c

   1 /*
   2  * Copyright (C) 2011 ST-Ericsson SA.
   3  * Copyright (C) 2009 Motorola, Inc.
   4  *
   5  * License Terms: GNU General Public License v2
   6  *
   7  * Simple driver for National Semiconductor LM3530 Backlight driver chip
   8  *
   9  * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
  10  * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
  11  */
  12
  13 #include <linux/i2c.h>
  14 #include <linux/leds.h>
  15 #include <linux/slab.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/input.h>
  18 #include <linux/led-lm3530.h>
  19 #include <linux/types.h>
  20 #include <linux/regulator/consumer.h>
  21
  22 #define LM3530_LED_DEV "lcd-backlight"
  23 #define LM3530_NAME "lm3530-led"
  24
  25 #define LM3530_GEN_CONFIG               0x10
  26 #define LM3530_ALS_CONFIG               0x20
  27 #define LM3530_BRT_RAMP_RATE            0x30
  28 #define LM3530_ALS_ZONE_REG             0x40
  29 #define LM3530_ALS_IMP_SELECT           0x41
  30 #define LM3530_BRT_CTRL_REG             0xA0
  31 #define LM3530_ALS_ZB0_REG              0x60
  32 #define LM3530_ALS_ZB1_REG              0x61
  33 #define LM3530_ALS_ZB2_REG              0x62
  34 #define LM3530_ALS_ZB3_REG              0x63
  35 #define LM3530_ALS_Z0T_REG              0x70
  36 #define LM3530_ALS_Z1T_REG              0x71
  37 #define LM3530_ALS_Z2T_REG              0x72
  38 #define LM3530_ALS_Z3T_REG              0x73
  39 #define LM3530_ALS_Z4T_REG              0x74
  40 #define LM3530_REG_MAX                  15
  41
  42 /* General Control Register */
  43 #define LM3530_EN_I2C_SHIFT             (0)
  44 #define LM3530_RAMP_LAW_SHIFT           (1)
  45 #define LM3530_MAX_CURR_SHIFT           (2)
  46 #define LM3530_EN_PWM_SHIFT             (5)
  47 #define LM3530_PWM_POL_SHIFT            (6)
  48 #define LM3530_EN_PWM_SIMPLE_SHIFT      (7)
  49
  50 #define LM3530_ENABLE_I2C               (1 << LM3530_EN_I2C_SHIFT)
  51 #define LM3530_ENABLE_PWM               (1 << LM3530_EN_PWM_SHIFT)
  52 #define LM3530_POL_LOW                  (1 << LM3530_PWM_POL_SHIFT)
  53 #define LM3530_ENABLE_PWM_SIMPLE        (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
  54
  55 /* ALS Config Register Options */
  56 #define LM3530_ALS_AVG_TIME_SHIFT       (0)
  57 #define LM3530_EN_ALS_SHIFT             (3)
  58 #define LM3530_ALS_SEL_SHIFT            (5)
  59
  60 #define LM3530_ENABLE_ALS               (3 << LM3530_EN_ALS_SHIFT)
  61
  62 /* Brightness Ramp Rate Register */
  63 #define LM3530_BRT_RAMP_FALL_SHIFT      (0)
  64 #define LM3530_BRT_RAMP_RISE_SHIFT      (3)
  65
  66 /* ALS Resistor Select */
  67 #define LM3530_ALS1_IMP_SHIFT           (0)
  68 #define LM3530_ALS2_IMP_SHIFT           (4)
  69
  70 /* Zone Boundary Register defaults */
  71 #define LM3530_ALS_ZB_MAX               (4)
  72 #define LM3530_ALS_WINDOW_mV            (1000)
  73 #define LM3530_ALS_OFFSET_mV            (4)
  74
  75 /* Zone Target Register defaults */
  76 #define LM3530_DEF_ZT_0                 (0x7F)
  77 #define LM3530_DEF_ZT_1                 (0x66)
  78 #define LM3530_DEF_ZT_2                 (0x4C)
  79 #define LM3530_DEF_ZT_3                 (0x33)
  80 #define LM3530_DEF_ZT_4                 (0x19)
  81
  82 struct lm3530_mode_map {
  83         const char *mode;
  84         enum lm3530_mode mode_val;
  85 };
  86
  87 static struct lm3530_mode_map mode_map[] = {
  88         { "man", LM3530_BL_MODE_MANUAL },
  89         { "als", LM3530_BL_MODE_ALS },
  90         { "pwm", LM3530_BL_MODE_PWM },
  91 };
  92
  93 /**
  94  * struct lm3530_data
  95  * @led_dev: led class device
  96  * @client: i2c client
  97  * @pdata: LM3530 platform data
  98  * @mode: mode of operation - manual, ALS, PWM
  99  * @regulator: regulator
 100  * @brighness: previous brightness value
 101  * @enable: regulator is enabled
 102  */
 103 struct lm3530_data {
 104         struct led_classdev led_dev;
 105         struct i2c_client *client;
 106         struct lm3530_platform_data *pdata;
 107         enum lm3530_mode mode;
 108         struct regulator *regulator;
 109         enum led_brightness brightness;
 110         bool enable;
 111 };
 112
 113 static const u8 lm3530_reg[LM3530_REG_MAX] = {
 114         LM3530_GEN_CONFIG,
 115         LM3530_ALS_CONFIG,
 116         LM3530_BRT_RAMP_RATE,
 117         LM3530_ALS_ZONE_REG,
 118         LM3530_ALS_IMP_SELECT,
 119         LM3530_BRT_CTRL_REG,
 120         LM3530_ALS_ZB0_REG,
 121         LM3530_ALS_ZB1_REG,
 122         LM3530_ALS_ZB2_REG,
 123         LM3530_ALS_ZB3_REG,
 124         LM3530_ALS_Z0T_REG,
 125         LM3530_ALS_Z1T_REG,
 126         LM3530_ALS_Z2T_REG,
 127         LM3530_ALS_Z3T_REG,
 128         LM3530_ALS_Z4T_REG,
 129 };
 130
 131 static int lm3530_get_mode_from_str(const char *str)
 132 {
 133         int i;
 134
 135         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 136                 if (sysfs_streq(str, mode_map[i].mode))
 137                         return mode_map[i].mode_val;
 138
 139         return -1;
 140 }
 141
 142 static int lm3530_init_registers(struct lm3530_data *drvdata)
 143 {
 144         int ret = 0;
 145         int i;
 146         u8 gen_config;
 147         u8 als_config = 0;
 148         u8 brt_ramp;
 149         u8 als_imp_sel = 0;
 150         u8 brightness;
 151         u8 reg_val[LM3530_REG_MAX];
 152         u8 zones[LM3530_ALS_ZB_MAX];
 153         u32 als_vmin, als_vmax, als_vstep;
 154         struct lm3530_platform_data *pltfm = drvdata->pdata;
 155         struct i2c_client *client = drvdata->client;
 156
 157         gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 158                         ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
 159
 160         if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
 161             drvdata->mode == LM3530_BL_MODE_ALS)
 162                 gen_config |= (LM3530_ENABLE_I2C);
 163
 164         if (drvdata->mode == LM3530_BL_MODE_ALS) {
 165                 if (pltfm->als_vmax == 0) {
 166                         pltfm->als_vmin = als_vmin = 0;
 167                         pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV;
 168                 }
 169
 170                 als_vmin = pltfm->als_vmin;
 171                 als_vmax = pltfm->als_vmax;
 172
 173                 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
 174                         pltfm->als_vmax = als_vmax =
 175                                 als_vmin + LM3530_ALS_WINDOW_mV;
 176
 177                 /* n zone boundary makes n+1 zones */
 178                 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
 179
 180                 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
 181                         zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
 182                                         als_vstep + (i * als_vstep)) * LED_FULL)
 183                                         / 1000;
 184
 185                 als_config =
 186                         (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 187                         (LM3530_ENABLE_ALS) |
 188                         (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
 189
 190                 als_imp_sel =
 191                         (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 192                         (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 193
 194         }
 195
 196         if (drvdata->mode == LM3530_BL_MODE_PWM)
 197                 gen_config |= (LM3530_ENABLE_PWM) |
 198                                 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
 199                                 (LM3530_ENABLE_PWM_SIMPLE);
 200
 201         brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 202                         (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 203
 204         if (drvdata->brightness)
 205                 brightness = drvdata->brightness;
 206         else
 207                 brightness = drvdata->brightness = pltfm->brt_val;
 208
 209         reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
 210         reg_val[1] = als_config;        /* LM3530_ALS_CONFIG */
 211         reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
 212         reg_val[3] = 0x00;              /* LM3530_ALS_ZONE_REG */
 213         reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
 214         reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
 215         reg_val[6] = zones[0];          /* LM3530_ALS_ZB0_REG */
 216         reg_val[7] = zones[1];          /* LM3530_ALS_ZB1_REG */
 217         reg_val[8] = zones[2];          /* LM3530_ALS_ZB2_REG */
 218         reg_val[9] = zones[3];          /* LM3530_ALS_ZB3_REG */
 219         reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
 220         reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
 221         reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
 222         reg_val[13] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
 223         reg_val[14] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
 224
 225         if (!drvdata->enable) {
 226                 ret = regulator_enable(drvdata->regulator);
 227                 if (ret) {
 228                         dev_err(&drvdata->client->dev,
 229                                         "Enable regulator failed\n");
 230                         return ret;
 231                 }
 232                 drvdata->enable = true;
 233         }
 234
 235         for (i = 0; i < LM3530_REG_MAX; i++) {
 236                 ret = i2c_smbus_write_byte_data(client,
 237                                 lm3530_reg[i], reg_val[i]);
 238                 if (ret)
 239                         break;
 240         }
 241
 242         return ret;
 243 }
 244
 245 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 246                                      enum led_brightness brt_val)
 247 {
 248         int err;
 249         struct lm3530_data *drvdata =
 250             container_of(led_cdev, struct lm3530_data, led_dev);
 251
 252         switch (drvdata->mode) {
 253         case LM3530_BL_MODE_MANUAL:
 254
 255                 if (!drvdata->enable) {
 256                         err = lm3530_init_registers(drvdata);
 257                         if (err) {
 258                                 dev_err(&drvdata->client->dev,
 259                                         "Register Init failed: %d\n", err);
 260                                 break;
 261                         }
 262                 }
 263
 264                 /* set the brightness in brightness control register*/
 265                 err = i2c_smbus_write_byte_data(drvdata->client,
 266                                 LM3530_BRT_CTRL_REG, brt_val / 2);
 267                 if (err)
 268                         dev_err(&drvdata->client->dev,
 269                                 "Unable to set brightness: %d\n", err);
 270                 else
 271                         drvdata->brightness = brt_val / 2;
 272
 273                 if (brt_val == 0) {
 274                         err = regulator_disable(drvdata->regulator);
 275                         if (err)
 276                                 dev_err(&drvdata->client->dev,
 277                                         "Disable regulator failed\n");
 278                         drvdata->enable = false;
 279                 }
 280                 break;
 281         case LM3530_BL_MODE_ALS:
 282                 break;
 283         case LM3530_BL_MODE_PWM:
 284                 break;
 285         default:
 286                 break;
 287         }
 288 }
 289
 290 static ssize_t lm3530_mode_get(struct device *dev,
 291                 struct device_attribute *attr, char *buf)
 292 {
 293         struct i2c_client *client = container_of(
 294                                         dev->parent, struct i2c_client, dev);
 295         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 296         int i, len = 0;
 297
 298         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 299                 if (drvdata->mode == mode_map[i].mode_val)
 300                         len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
 301                 else
 302                         len += sprintf(buf + len, "%s ", mode_map[i].mode);
 303
 304         len += sprintf(buf + len, "\n");
 305
 306         return len;
 307 }
 308
 309 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 310                                    *attr, const char *buf, size_t size)
 311 {
 312         int err;
 313         struct i2c_client *client = container_of(
 314                                         dev->parent, struct i2c_client, dev);
 315         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 316         int mode;
 317
 318         mode = lm3530_get_mode_from_str(buf);
 319         if (mode < 0) {
 320                 dev_err(dev, "Invalid mode\n");
 321                 return -EINVAL;
 322         }
 323
 324         if (mode == LM3530_BL_MODE_MANUAL)
 325                 drvdata->mode = LM3530_BL_MODE_MANUAL;
 326         else if (mode == LM3530_BL_MODE_ALS)
 327                 drvdata->mode = LM3530_BL_MODE_ALS;
 328         else if (mode == LM3530_BL_MODE_PWM) {
 329                 dev_err(dev, "PWM mode not supported\n");
 330                 return -EINVAL;
 331         }
 332
 333         err = lm3530_init_registers(drvdata);
 334         if (err) {
 335                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 336                 return err;
 337         }
 338
 339         return sizeof(drvdata->mode);
 340 }
 341 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
 342
 343 static int __devinit lm3530_probe(struct i2c_client *client,
 344                            const struct i2c_device_id *id)
 345 {
 346         struct lm3530_platform_data *pdata = client->dev.platform_data;
 347         struct lm3530_data *drvdata;
 348         int err = 0;
 349
 350         if (pdata == NULL) {
 351                 dev_err(&client->dev, "platform data required\n");
 352                 err = -ENODEV;
 353                 goto err_out;
 354         }
 355
 356         /* BL mode */
 357         if (pdata->mode > LM3530_BL_MODE_PWM) {
 358                 dev_err(&client->dev, "Illegal Mode request\n");
 359                 err = -EINVAL;
 360                 goto err_out;
 361         }
 362
 363         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 364                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 365                 err = -EIO;
 366                 goto err_out;
 367         }
 368
 369         drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 370         if (drvdata == NULL) {
 371                 err = -ENOMEM;
 372                 goto err_out;
 373         }
 374
 375         drvdata->mode = pdata->mode;
 376         drvdata->client = client;
 377         drvdata->pdata = pdata;
 378         drvdata->brightness = LED_OFF;
 379         drvdata->enable = false;
 380         drvdata->led_dev.name = LM3530_LED_DEV;
 381         drvdata->led_dev.brightness_set = lm3530_brightness_set;
 382
 383         i2c_set_clientdata(client, drvdata);
 384
 385         drvdata->regulator = regulator_get(&client->dev, "vin");
 386         if (IS_ERR(drvdata->regulator)) {
 387                 dev_err(&client->dev, "regulator get failed\n");
 388                 err = PTR_ERR(drvdata->regulator);
 389                 drvdata->regulator = NULL;
 390                 goto err_regulator_get;
 391         }
 392
 393         if (drvdata->pdata->brt_val) {
 394                 err = lm3530_init_registers(drvdata);
 395                 if (err < 0) {
 396                         dev_err(&client->dev,
 397                                 "Register Init failed: %d\n", err);
 398                         err = -ENODEV;
 399                         goto err_reg_init;
 400                 }
 401         }
 402         err = led_classdev_register(&client->dev, &drvdata->led_dev);
 403         if (err < 0) {
 404                 dev_err(&client->dev, "Register led class failed: %d\n", err);
 405                 err = -ENODEV;
 406                 goto err_class_register;
 407         }
 408
 409         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 410         if (err < 0) {
 411                 dev_err(&client->dev, "File device creation failed: %d\n", err);
 412                 err = -ENODEV;
 413                 goto err_create_file;
 414         }
 415
 416         return 0;
 417
 418 err_create_file:
 419         led_classdev_unregister(&drvdata->led_dev);
 420 err_class_register:
 421 err_reg_init:
 422         regulator_put(drvdata->regulator);
 423 err_regulator_get:
 424         i2c_set_clientdata(client, NULL);
 425         kfree(drvdata);
 426 err_out:
 427         return err;
 428 }
 429
 430 static int __devexit lm3530_remove(struct i2c_client *client)
 431 {
 432         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 433
 434         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 435
 436         if (drvdata->enable)
 437                 regulator_disable(drvdata->regulator);
 438         regulator_put(drvdata->regulator);
 439         led_classdev_unregister(&drvdata->led_dev);
 440         kfree(drvdata);
 441         return 0;
 442 }
 443
 444 static const struct i2c_device_id lm3530_id[] = {
 445         {LM3530_NAME, 0},
 446         {}
 447 };
 448 MODULE_DEVICE_TABLE(i2c, lm3530_id);
 449
 450 static struct i2c_driver lm3530_i2c_driver = {
 451         .probe = lm3530_probe,
 452         .remove = lm3530_remove,
 453         .id_table = lm3530_id,
 454         .driver = {
 455                 .name = LM3530_NAME,
 456                 .owner = THIS_MODULE,
 457         },
 458 };
 459
 460 static int __init lm3530_init(void)
 461 {
 462         return i2c_add_driver(&lm3530_i2c_driver);
 463 }
 464
 465 static void __exit lm3530_exit(void)
 466 {
 467         i2c_del_driver(&lm3530_i2c_driver);
 468 }
 469
 470 module_init(lm3530_init);
 471 module_exit(lm3530_exit);
 472
 473 MODULE_DESCRIPTION("Back Light driver for LM3530");
 474 MODULE_LICENSE("GPL v2");
 475 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");