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