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_DEF_ZB_0                 (0x33)
  72 #define LM3530_DEF_ZB_1                 (0x66)
  73 #define LM3530_DEF_ZB_2                 (0x99)
  74 #define LM3530_DEF_ZB_3                 (0xCC)
  75
  76 /* Zone Target Register defaults */
  77 #define LM3530_DEF_ZT_0                 (0x19)
  78 #define LM3530_DEF_ZT_1                 (0x33)
  79 #define LM3530_DEF_ZT_2                 (0x4C)
  80 #define LM3530_DEF_ZT_3                 (0x66)
  81 #define LM3530_DEF_ZT_4                 (0x7F)
  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         struct lm3530_platform_data *pltfm = drvdata->pdata;
 154         struct i2c_client *client = drvdata->client;
 155
 156         gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 157                         ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
 158
 159         if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
 160             drvdata->mode == LM3530_BL_MODE_ALS)
 161                 gen_config |= (LM3530_ENABLE_I2C);
 162
 163         if (drvdata->mode == LM3530_BL_MODE_ALS) {
 164                 als_config =
 165                         (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 166                         (LM3530_ENABLE_ALS) |
 167                         (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
 168
 169                 als_imp_sel =
 170                         (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 171                         (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 172         }
 173
 174         if (drvdata->mode == LM3530_BL_MODE_PWM)
 175                 gen_config |= (LM3530_ENABLE_PWM) |
 176                                 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
 177                                 (LM3530_ENABLE_PWM_SIMPLE);
 178
 179         brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 180                         (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 181
 182         if (drvdata->brightness)
 183                 brightness = drvdata->brightness;
 184         else
 185                 brightness = drvdata->brightness = pltfm->brt_val;
 186
 187         reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
 188         reg_val[1] = als_config;        /* LM3530_ALS_CONFIG */
 189         reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
 190         reg_val[3] = 0x00;              /* LM3530_ALS_ZONE_REG */
 191         reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
 192         reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
 193         reg_val[6] = LM3530_DEF_ZB_0;   /* LM3530_ALS_ZB0_REG */
 194         reg_val[7] = LM3530_DEF_ZB_1;   /* LM3530_ALS_ZB1_REG */
 195         reg_val[8] = LM3530_DEF_ZB_2;   /* LM3530_ALS_ZB2_REG */
 196         reg_val[9] = LM3530_DEF_ZB_3;   /* LM3530_ALS_ZB3_REG */
 197         reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
 198         reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
 199         reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
 200         reg_val[13] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
 201         reg_val[14] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
 202
 203         if (!drvdata->enable) {
 204                 ret = regulator_enable(drvdata->regulator);
 205                 if (ret) {
 206                         dev_err(&drvdata->client->dev,
 207                                         "Enable regulator failed\n");
 208                         return ret;
 209                 }
 210                 drvdata->enable = true;
 211         }
 212
 213         for (i = 0; i < LM3530_REG_MAX; i++) {
 214                 ret = i2c_smbus_write_byte_data(client,
 215                                 lm3530_reg[i], reg_val[i]);
 216                 if (ret)
 217                         break;
 218         }
 219
 220         return ret;
 221 }
 222
 223 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 224                                      enum led_brightness brt_val)
 225 {
 226         int err;
 227         struct lm3530_data *drvdata =
 228             container_of(led_cdev, struct lm3530_data, led_dev);
 229
 230         switch (drvdata->mode) {
 231         case LM3530_BL_MODE_MANUAL:
 232
 233                 if (!drvdata->enable) {
 234                         err = lm3530_init_registers(drvdata);
 235                         if (err) {
 236                                 dev_err(&drvdata->client->dev,
 237                                         "Register Init failed: %d\n", err);
 238                                 break;
 239                         }
 240                 }
 241
 242                 /* set the brightness in brightness control register*/
 243                 err = i2c_smbus_write_byte_data(drvdata->client,
 244                                 LM3530_BRT_CTRL_REG, brt_val / 2);
 245                 if (err)
 246                         dev_err(&drvdata->client->dev,
 247                                 "Unable to set brightness: %d\n", err);
 248                 else
 249                         drvdata->brightness = brt_val / 2;
 250
 251                 if (brt_val == 0) {
 252                         err = regulator_disable(drvdata->regulator);
 253                         if (err)
 254                                 dev_err(&drvdata->client->dev,
 255                                         "Disable regulator failed\n");
 256                         drvdata->enable = false;
 257                 }
 258                 break;
 259         case LM3530_BL_MODE_ALS:
 260                 break;
 261         case LM3530_BL_MODE_PWM:
 262                 break;
 263         default:
 264                 break;
 265         }
 266 }
 267
 268
 269 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 270                                    *attr, const char *buf, size_t size)
 271 {
 272         int err;
 273         struct i2c_client *client = container_of(
 274                                         dev->parent, struct i2c_client, dev);
 275         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 276         int mode;
 277
 278         mode = lm3530_get_mode_from_str(buf);
 279         if (mode < 0) {
 280                 dev_err(dev, "Invalid mode\n");
 281                 return -EINVAL;
 282         }
 283
 284         if (mode == LM3530_BL_MODE_MANUAL)
 285                 drvdata->mode = LM3530_BL_MODE_MANUAL;
 286         else if (mode == LM3530_BL_MODE_ALS)
 287                 drvdata->mode = LM3530_BL_MODE_ALS;
 288         else if (mode == LM3530_BL_MODE_PWM) {
 289                 dev_err(dev, "PWM mode not supported\n");
 290                 return -EINVAL;
 291         }
 292
 293         err = lm3530_init_registers(drvdata);
 294         if (err) {
 295                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 296                 return err;
 297         }
 298
 299         return sizeof(drvdata->mode);
 300 }
 301
 302 static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
 303
 304 static int __devinit lm3530_probe(struct i2c_client *client,
 305                            const struct i2c_device_id *id)
 306 {
 307         struct lm3530_platform_data *pdata = client->dev.platform_data;
 308         struct lm3530_data *drvdata;
 309         int err = 0;
 310
 311         if (pdata == NULL) {
 312                 dev_err(&client->dev, "platform data required\n");
 313                 err = -ENODEV;
 314                 goto err_out;
 315         }
 316
 317         /* BL mode */
 318         if (pdata->mode > LM3530_BL_MODE_PWM) {
 319                 dev_err(&client->dev, "Illegal Mode request\n");
 320                 err = -EINVAL;
 321                 goto err_out;
 322         }
 323
 324         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 325                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 326                 err = -EIO;
 327                 goto err_out;
 328         }
 329
 330         drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 331         if (drvdata == NULL) {
 332                 err = -ENOMEM;
 333                 goto err_out;
 334         }
 335
 336         drvdata->mode = pdata->mode;
 337         drvdata->client = client;
 338         drvdata->pdata = pdata;
 339         drvdata->brightness = LED_OFF;
 340         drvdata->enable = false;
 341         drvdata->led_dev.name = LM3530_LED_DEV;
 342         drvdata->led_dev.brightness_set = lm3530_brightness_set;
 343
 344         i2c_set_clientdata(client, drvdata);
 345
 346         drvdata->regulator = regulator_get(&client->dev, "vin");
 347         if (IS_ERR(drvdata->regulator)) {
 348                 dev_err(&client->dev, "regulator get failed\n");
 349                 err = PTR_ERR(drvdata->regulator);
 350                 drvdata->regulator = NULL;
 351                 goto err_regulator_get;
 352         }
 353
 354         if (drvdata->pdata->brt_val) {
 355                 err = lm3530_init_registers(drvdata);
 356                 if (err < 0) {
 357                         dev_err(&client->dev,
 358                                 "Register Init failed: %d\n", err);
 359                         err = -ENODEV;
 360                         goto err_reg_init;
 361                 }
 362         }
 363         err = led_classdev_register(&client->dev, &drvdata->led_dev);
 364         if (err < 0) {
 365                 dev_err(&client->dev, "Register led class failed: %d\n", err);
 366                 err = -ENODEV;
 367                 goto err_class_register;
 368         }
 369
 370         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 371         if (err < 0) {
 372                 dev_err(&client->dev, "File device creation failed: %d\n", err);
 373                 err = -ENODEV;
 374                 goto err_create_file;
 375         }
 376
 377         return 0;
 378
 379 err_create_file:
 380         led_classdev_unregister(&drvdata->led_dev);
 381 err_class_register:
 382 err_reg_init:
 383         regulator_put(drvdata->regulator);
 384 err_regulator_get:
 385         i2c_set_clientdata(client, NULL);
 386         kfree(drvdata);
 387 err_out:
 388         return err;
 389 }
 390
 391 static int __devexit lm3530_remove(struct i2c_client *client)
 392 {
 393         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 394
 395         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 396
 397         if (drvdata->enable)
 398                 regulator_disable(drvdata->regulator);
 399         regulator_put(drvdata->regulator);
 400         led_classdev_unregister(&drvdata->led_dev);
 401         kfree(drvdata);
 402         return 0;
 403 }
 404
 405 static const struct i2c_device_id lm3530_id[] = {
 406         {LM3530_NAME, 0},
 407         {}
 408 };
 409 MODULE_DEVICE_TABLE(i2c, lm3530_id);
 410
 411 static struct i2c_driver lm3530_i2c_driver = {
 412         .probe = lm3530_probe,
 413         .remove = lm3530_remove,
 414         .id_table = lm3530_id,
 415         .driver = {
 416                 .name = LM3530_NAME,
 417                 .owner = THIS_MODULE,
 418         },
 419 };
 420
 421 static int __init lm3530_init(void)
 422 {
 423         return i2c_add_driver(&lm3530_i2c_driver);
 424 }
 425
 426 static void __exit lm3530_exit(void)
 427 {
 428         i2c_del_driver(&lm3530_i2c_driver);
 429 }
 430
 431 module_init(lm3530_init);
 432 module_exit(lm3530_exit);
 433
 434 MODULE_DESCRIPTION("Back Light driver for LM3530");
 435 MODULE_LICENSE("GPL v2");
 436 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");