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 #include <linux/module.h>
  22
  23 #define LM3530_LED_DEV "lcd-backlight"
  24 #define LM3530_NAME "lm3530-led"
  25
  26 #define LM3530_GEN_CONFIG               0x10
  27 #define LM3530_ALS_CONFIG               0x20
  28 #define LM3530_BRT_RAMP_RATE            0x30
  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                  14
  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 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
  83 #define MAX_BRIGHTNESS                  (127)
  84
  85 struct lm3530_mode_map {
  86         const char *mode;
  87         enum lm3530_mode mode_val;
  88 };
  89
  90 static struct lm3530_mode_map mode_map[] = {
  91         { "man", LM3530_BL_MODE_MANUAL },
  92         { "als", LM3530_BL_MODE_ALS },
  93         { "pwm", LM3530_BL_MODE_PWM },
  94 };
  95
  96 /**
  97  * struct lm3530_data
  98  * @led_dev: led class device
  99  * @client: i2c client
 100  * @pdata: LM3530 platform data
 101  * @mode: mode of operation - manual, ALS, PWM
 102  * @regulator: regulator
 103  * @brighness: previous brightness value
 104  * @enable: regulator is enabled
 105  */
 106 struct lm3530_data {
 107         struct led_classdev led_dev;
 108         struct i2c_client *client;
 109         struct lm3530_platform_data *pdata;
 110         enum lm3530_mode mode;
 111         struct regulator *regulator;
 112         enum led_brightness brightness;
 113         bool enable;
 114 };
 115
 116 static const u8 lm3530_reg[LM3530_REG_MAX] = {
 117         LM3530_GEN_CONFIG,
 118         LM3530_ALS_CONFIG,
 119         LM3530_BRT_RAMP_RATE,
 120         LM3530_ALS_IMP_SELECT,
 121         LM3530_BRT_CTRL_REG,
 122         LM3530_ALS_ZB0_REG,
 123         LM3530_ALS_ZB1_REG,
 124         LM3530_ALS_ZB2_REG,
 125         LM3530_ALS_ZB3_REG,
 126         LM3530_ALS_Z0T_REG,
 127         LM3530_ALS_Z1T_REG,
 128         LM3530_ALS_Z2T_REG,
 129         LM3530_ALS_Z3T_REG,
 130         LM3530_ALS_Z4T_REG,
 131 };
 132
 133 static int lm3530_get_mode_from_str(const char *str)
 134 {
 135         int i;
 136
 137         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 138                 if (sysfs_streq(str, mode_map[i].mode))
 139                         return mode_map[i].mode_val;
 140
 141         return -1;
 142 }
 143
 144 static int lm3530_init_registers(struct lm3530_data *drvdata)
 145 {
 146         int ret = 0;
 147         int i;
 148         u8 gen_config;
 149         u8 als_config = 0;
 150         u8 brt_ramp;
 151         u8 als_imp_sel = 0;
 152         u8 brightness;
 153         u8 reg_val[LM3530_REG_MAX];
 154         u8 zones[LM3530_ALS_ZB_MAX];
 155         u32 als_vmin, als_vmax, als_vstep;
 156         struct lm3530_platform_data *pdata = drvdata->pdata;
 157         struct i2c_client *client = drvdata->client;
 158         struct lm3530_pwm_data *pwm = &pdata->pwm_data;
 159
 160         gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 161                         ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
 162
 163         switch (drvdata->mode) {
 164         case LM3530_BL_MODE_MANUAL:
 165         case LM3530_BL_MODE_ALS:
 166                 gen_config |= LM3530_ENABLE_I2C;
 167                 break;
 168         case LM3530_BL_MODE_PWM:
 169                 gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
 170                               (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
 171                 break;
 172         }
 173
 174         if (drvdata->mode == LM3530_BL_MODE_ALS) {
 175                 if (pdata->als_vmax == 0) {
 176                         pdata->als_vmin = 0;
 177                         pdata->als_vmax = LM3530_ALS_WINDOW_mV;
 178                 }
 179
 180                 als_vmin = pdata->als_vmin;
 181                 als_vmax = pdata->als_vmax;
 182
 183                 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
 184                         pdata->als_vmax = als_vmax =
 185                                 als_vmin + LM3530_ALS_WINDOW_mV;
 186
 187                 /* n zone boundary makes n+1 zones */
 188                 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
 189
 190                 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
 191                         zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
 192                                         als_vstep + (i * als_vstep)) * LED_FULL)
 193                                         / 1000;
 194
 195                 als_config =
 196                         (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 197                         (LM3530_ENABLE_ALS) |
 198                         (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
 199
 200                 als_imp_sel =
 201                         (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 202                         (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 203
 204         }
 205
 206         brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 207                         (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 208
 209         if (drvdata->brightness)
 210                 brightness = drvdata->brightness;
 211         else
 212                 brightness = drvdata->brightness = pdata->brt_val;
 213
 214         if (brightness > drvdata->led_dev.max_brightness)
 215                 brightness = drvdata->led_dev.max_brightness;
 216
 217         reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
 218         reg_val[1] = als_config;        /* LM3530_ALS_CONFIG */
 219         reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
 220         reg_val[3] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
 221         reg_val[4] = brightness;        /* LM3530_BRT_CTRL_REG */
 222         reg_val[5] = zones[0];          /* LM3530_ALS_ZB0_REG */
 223         reg_val[6] = zones[1];          /* LM3530_ALS_ZB1_REG */
 224         reg_val[7] = zones[2];          /* LM3530_ALS_ZB2_REG */
 225         reg_val[8] = zones[3];          /* LM3530_ALS_ZB3_REG */
 226         reg_val[9] = LM3530_DEF_ZT_0;   /* LM3530_ALS_Z0T_REG */
 227         reg_val[10] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
 228         reg_val[11] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
 229         reg_val[12] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
 230         reg_val[13] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
 231
 232         if (!drvdata->enable) {
 233                 ret = regulator_enable(drvdata->regulator);
 234                 if (ret) {
 235                         dev_err(&drvdata->client->dev,
 236                                         "Enable regulator failed\n");
 237                         return ret;
 238                 }
 239                 drvdata->enable = true;
 240         }
 241
 242         for (i = 0; i < LM3530_REG_MAX; i++) {
 243                 /* do not update brightness register when pwm mode */
 244                 if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
 245                     drvdata->mode == LM3530_BL_MODE_PWM) {
 246                         if (pwm->pwm_set_intensity)
 247                                 pwm->pwm_set_intensity(reg_val[i],
 248                                         drvdata->led_dev.max_brightness);
 249                         continue;
 250                 }
 251
 252                 ret = i2c_smbus_write_byte_data(client,
 253                                 lm3530_reg[i], reg_val[i]);
 254                 if (ret)
 255                         break;
 256         }
 257
 258         return ret;
 259 }
 260
 261 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 262                                      enum led_brightness brt_val)
 263 {
 264         int err;
 265         struct lm3530_data *drvdata =
 266             container_of(led_cdev, struct lm3530_data, led_dev);
 267         struct lm3530_platform_data *pdata = drvdata->pdata;
 268         struct lm3530_pwm_data *pwm = &pdata->pwm_data;
 269         u8 max_brightness = led_cdev->max_brightness;
 270
 271         switch (drvdata->mode) {
 272         case LM3530_BL_MODE_MANUAL:
 273
 274                 if (!drvdata->enable) {
 275                         err = lm3530_init_registers(drvdata);
 276                         if (err) {
 277                                 dev_err(&drvdata->client->dev,
 278                                         "Register Init failed: %d\n", err);
 279                                 break;
 280                         }
 281                 }
 282
 283                 /* set the brightness in brightness control register*/
 284                 err = i2c_smbus_write_byte_data(drvdata->client,
 285                                 LM3530_BRT_CTRL_REG, brt_val);
 286                 if (err)
 287                         dev_err(&drvdata->client->dev,
 288                                 "Unable to set brightness: %d\n", err);
 289                 else
 290                         drvdata->brightness = brt_val;
 291
 292                 if (brt_val == 0) {
 293                         err = regulator_disable(drvdata->regulator);
 294                         if (err)
 295                                 dev_err(&drvdata->client->dev,
 296                                         "Disable regulator failed\n");
 297                         drvdata->enable = false;
 298                 }
 299                 break;
 300         case LM3530_BL_MODE_ALS:
 301                 break;
 302         case LM3530_BL_MODE_PWM:
 303                 if (pwm->pwm_set_intensity)
 304                         pwm->pwm_set_intensity(brt_val, max_brightness);
 305                 break;
 306         default:
 307                 break;
 308         }
 309 }
 310
 311 static ssize_t lm3530_mode_get(struct device *dev,
 312                 struct device_attribute *attr, char *buf)
 313 {
 314         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 315         struct lm3530_data *drvdata;
 316         int i, len = 0;
 317
 318         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
 319         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 320                 if (drvdata->mode == mode_map[i].mode_val)
 321                         len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
 322                 else
 323                         len += sprintf(buf + len, "%s ", mode_map[i].mode);
 324
 325         len += sprintf(buf + len, "\n");
 326
 327         return len;
 328 }
 329
 330 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 331                                    *attr, const char *buf, size_t size)
 332 {
 333         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 334         struct lm3530_data *drvdata;
 335         struct lm3530_pwm_data *pwm;
 336         u8 max_brightness;
 337         int mode, err;
 338
 339         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
 340         pwm = &drvdata->pdata->pwm_data;
 341         max_brightness = led_cdev->max_brightness;
 342         mode = lm3530_get_mode_from_str(buf);
 343         if (mode < 0) {
 344                 dev_err(dev, "Invalid mode\n");
 345                 return -EINVAL;
 346         }
 347
 348         drvdata->mode = mode;
 349
 350         /* set pwm to low if unnecessary */
 351         if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
 352                 pwm->pwm_set_intensity(0, max_brightness);
 353
 354         err = lm3530_init_registers(drvdata);
 355         if (err) {
 356                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 357                 return err;
 358         }
 359
 360         return sizeof(drvdata->mode);
 361 }
 362 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
 363
 364 static int __devinit lm3530_probe(struct i2c_client *client,
 365                            const struct i2c_device_id *id)
 366 {
 367         struct lm3530_platform_data *pdata = client->dev.platform_data;
 368         struct lm3530_data *drvdata;
 369         int err = 0;
 370
 371         if (pdata == NULL) {
 372                 dev_err(&client->dev, "platform data required\n");
 373                 err = -ENODEV;
 374                 goto err_out;
 375         }
 376
 377         /* BL mode */
 378         if (pdata->mode > LM3530_BL_MODE_PWM) {
 379                 dev_err(&client->dev, "Illegal Mode request\n");
 380                 err = -EINVAL;
 381                 goto err_out;
 382         }
 383
 384         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 385                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 386                 err = -EIO;
 387                 goto err_out;
 388         }
 389
 390         drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 391         if (drvdata == NULL) {
 392                 err = -ENOMEM;
 393                 goto err_out;
 394         }
 395
 396         drvdata->mode = pdata->mode;
 397         drvdata->client = client;
 398         drvdata->pdata = pdata;
 399         drvdata->brightness = LED_OFF;
 400         drvdata->enable = false;
 401         drvdata->led_dev.name = LM3530_LED_DEV;
 402         drvdata->led_dev.brightness_set = lm3530_brightness_set;
 403         drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
 404
 405         i2c_set_clientdata(client, drvdata);
 406
 407         drvdata->regulator = regulator_get(&client->dev, "vin");
 408         if (IS_ERR(drvdata->regulator)) {
 409                 dev_err(&client->dev, "regulator get failed\n");
 410                 err = PTR_ERR(drvdata->regulator);
 411                 drvdata->regulator = NULL;
 412                 goto err_regulator_get;
 413         }
 414
 415         if (drvdata->pdata->brt_val) {
 416                 err = lm3530_init_registers(drvdata);
 417                 if (err < 0) {
 418                         dev_err(&client->dev,
 419                                 "Register Init failed: %d\n", err);
 420                         err = -ENODEV;
 421                         goto err_reg_init;
 422                 }
 423         }
 424         err = led_classdev_register(&client->dev, &drvdata->led_dev);
 425         if (err < 0) {
 426                 dev_err(&client->dev, "Register led class failed: %d\n", err);
 427                 err = -ENODEV;
 428                 goto err_class_register;
 429         }
 430
 431         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 432         if (err < 0) {
 433                 dev_err(&client->dev, "File device creation failed: %d\n", err);
 434                 err = -ENODEV;
 435                 goto err_create_file;
 436         }
 437
 438         return 0;
 439
 440 err_create_file:
 441         led_classdev_unregister(&drvdata->led_dev);
 442 err_class_register:
 443 err_reg_init:
 444         regulator_put(drvdata->regulator);
 445 err_regulator_get:
 446         kfree(drvdata);
 447 err_out:
 448         return err;
 449 }
 450
 451 static int __devexit lm3530_remove(struct i2c_client *client)
 452 {
 453         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 454
 455         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 456
 457         if (drvdata->enable)
 458                 regulator_disable(drvdata->regulator);
 459         regulator_put(drvdata->regulator);
 460         led_classdev_unregister(&drvdata->led_dev);
 461         kfree(drvdata);
 462         return 0;
 463 }
 464
 465 static const struct i2c_device_id lm3530_id[] = {
 466         {LM3530_NAME, 0},
 467         {}
 468 };
 469 MODULE_DEVICE_TABLE(i2c, lm3530_id);
 470
 471 static struct i2c_driver lm3530_i2c_driver = {
 472         .probe = lm3530_probe,
 473         .remove = __devexit_p(lm3530_remove),
 474         .id_table = lm3530_id,
 475         .driver = {
 476                 .name = LM3530_NAME,
 477                 .owner = THIS_MODULE,
 478         },
 479 };
 480
 481 module_i2c_driver(lm3530_i2c_driver);
 482
 483 MODULE_DESCRIPTION("Back Light driver for LM3530");
 484 MODULE_LICENSE("GPL v2");
 485 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");