Pileus Git - ~andy/linux/blob - 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 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
  84 #define MAX_BRIGHTNESS                  (127)
  85
  86 struct lm3530_mode_map {
  87         const char *mode;
  88         enum lm3530_mode mode_val;
  89 };
  90
  91 static struct lm3530_mode_map mode_map[] = {
  92         { "man", LM3530_BL_MODE_MANUAL },
  93         { "als", LM3530_BL_MODE_ALS },
  94         { "pwm", LM3530_BL_MODE_PWM },
  95 };
  96
  97 /**
  98  * struct lm3530_data
  99  * @led_dev: led class device
 100  * @client: i2c client
 101  * @pdata: LM3530 platform data
 102  * @mode: mode of operation - manual, ALS, PWM
 103  * @regulator: regulator
 104  * @brighness: previous brightness value
 105  * @enable: regulator is enabled
 106  */
 107 struct lm3530_data {
 108         struct led_classdev led_dev;
 109         struct i2c_client *client;
 110         struct lm3530_platform_data *pdata;
 111         enum lm3530_mode mode;
 112         struct regulator *regulator;
 113         enum led_brightness brightness;
 114         bool enable;
 115 };
 116
 117 static const u8 lm3530_reg[LM3530_REG_MAX] = {
 118         LM3530_GEN_CONFIG,
 119         LM3530_ALS_CONFIG,
 120         LM3530_BRT_RAMP_RATE,
 121         LM3530_ALS_ZONE_REG,
 122         LM3530_ALS_IMP_SELECT,
 123         LM3530_BRT_CTRL_REG,
 124         LM3530_ALS_ZB0_REG,
 125         LM3530_ALS_ZB1_REG,
 126         LM3530_ALS_ZB2_REG,
 127         LM3530_ALS_ZB3_REG,
 128         LM3530_ALS_Z0T_REG,
 129         LM3530_ALS_Z1T_REG,
 130         LM3530_ALS_Z2T_REG,
 131         LM3530_ALS_Z3T_REG,
 132         LM3530_ALS_Z4T_REG,
 133 };
 134
 135 static int lm3530_get_mode_from_str(const char *str)
 136 {
 137         int i;
 138
 139         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 140                 if (sysfs_streq(str, mode_map[i].mode))
 141                         return mode_map[i].mode_val;
 142
 143         return -1;
 144 }
 145
 146 static int lm3530_init_registers(struct lm3530_data *drvdata)
 147 {
 148         int ret = 0;
 149         int i;
 150         u8 gen_config;
 151         u8 als_config = 0;
 152         u8 brt_ramp;
 153         u8 als_imp_sel = 0;
 154         u8 brightness;
 155         u8 reg_val[LM3530_REG_MAX];
 156         u8 zones[LM3530_ALS_ZB_MAX];
 157         u32 als_vmin, als_vmax, als_vstep;
 158         struct lm3530_platform_data *pltfm = drvdata->pdata;
 159         struct i2c_client *client = drvdata->client;
 160         struct lm3530_pwm_data *pwm = &pltfm->pwm_data;
 161
 162         gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 163                         ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
 164
 165         if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
 166             drvdata->mode == LM3530_BL_MODE_ALS)
 167                 gen_config |= (LM3530_ENABLE_I2C);
 168
 169         if (drvdata->mode == LM3530_BL_MODE_ALS) {
 170                 if (pltfm->als_vmax == 0) {
 171                         pltfm->als_vmin = 0;
 172                         pltfm->als_vmax = LM3530_ALS_WINDOW_mV;
 173                 }
 174
 175                 als_vmin = pltfm->als_vmin;
 176                 als_vmax = pltfm->als_vmax;
 177
 178                 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
 179                         pltfm->als_vmax = als_vmax =
 180                                 als_vmin + LM3530_ALS_WINDOW_mV;
 181
 182                 /* n zone boundary makes n+1 zones */
 183                 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
 184
 185                 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
 186                         zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
 187                                         als_vstep + (i * als_vstep)) * LED_FULL)
 188                                         / 1000;
 189
 190                 als_config =
 191                         (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 192                         (LM3530_ENABLE_ALS) |
 193                         (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
 194
 195                 als_imp_sel =
 196                         (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 197                         (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 198
 199         }
 200
 201         if (drvdata->mode == LM3530_BL_MODE_PWM)
 202                 gen_config |= (LM3530_ENABLE_PWM) |
 203                                 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
 204                                 (LM3530_ENABLE_PWM_SIMPLE);
 205
 206         brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 207                         (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 208
 209         if (drvdata->brightness)
 210                 brightness = drvdata->brightness;
 211         else
 212                 brightness = drvdata->brightness = pltfm->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] = 0x00;              /* LM3530_ALS_ZONE_REG */
 221         reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
 222         reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
 223         reg_val[6] = zones[0];          /* LM3530_ALS_ZB0_REG */
 224         reg_val[7] = zones[1];          /* LM3530_ALS_ZB1_REG */
 225         reg_val[8] = zones[2];          /* LM3530_ALS_ZB2_REG */
 226         reg_val[9] = zones[3];          /* LM3530_ALS_ZB3_REG */
 227         reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
 228         reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
 229         reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
 230         reg_val[13] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
 231         reg_val[14] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
 232
 233         if (!drvdata->enable) {
 234                 ret = regulator_enable(drvdata->regulator);
 235                 if (ret) {
 236                         dev_err(&drvdata->client->dev,
 237                                         "Enable regulator failed\n");
 238                         return ret;
 239                 }
 240                 drvdata->enable = true;
 241         }
 242
 243         for (i = 0; i < LM3530_REG_MAX; i++) {
 244                 /* do not update brightness register when pwm mode */
 245                 if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
 246                     drvdata->mode == LM3530_BL_MODE_PWM) {
 247                         if (pwm->pwm_set_intensity)
 248                                 pwm->pwm_set_intensity(reg_val[i],
 249                                         drvdata->led_dev.max_brightness);
 250                         continue;
 251                 }
 252
 253                 ret = i2c_smbus_write_byte_data(client,
 254                                 lm3530_reg[i], reg_val[i]);
 255                 if (ret)
 256                         break;
 257         }
 258
 259         return ret;
 260 }
 261
 262 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 263                                      enum led_brightness brt_val)
 264 {
 265         int err;
 266         struct lm3530_data *drvdata =
 267             container_of(led_cdev, struct lm3530_data, led_dev);
 268         struct lm3530_platform_data *pdata = drvdata->pdata;
 269         struct lm3530_pwm_data *pwm = &pdata->pwm_data;
 270         u8 max_brightness = led_cdev->max_brightness;
 271
 272         switch (drvdata->mode) {
 273         case LM3530_BL_MODE_MANUAL:
 274
 275                 if (!drvdata->enable) {
 276                         err = lm3530_init_registers(drvdata);
 277                         if (err) {
 278                                 dev_err(&drvdata->client->dev,
 279                                         "Register Init failed: %d\n", err);
 280                                 break;
 281                         }
 282                 }
 283
 284                 /* set the brightness in brightness control register*/
 285                 err = i2c_smbus_write_byte_data(drvdata->client,
 286                                 LM3530_BRT_CTRL_REG, brt_val);
 287                 if (err)
 288                         dev_err(&drvdata->client->dev,
 289                                 "Unable to set brightness: %d\n", err);
 290                 else
 291                         drvdata->brightness = brt_val;
 292
 293                 if (brt_val == 0) {
 294                         err = regulator_disable(drvdata->regulator);
 295                         if (err)
 296                                 dev_err(&drvdata->client->dev,
 297                                         "Disable regulator failed\n");
 298                         drvdata->enable = false;
 299                 }
 300                 break;
 301         case LM3530_BL_MODE_ALS:
 302                 break;
 303         case LM3530_BL_MODE_PWM:
 304                 if (pwm->pwm_set_intensity)
 305                         pwm->pwm_set_intensity(brt_val, max_brightness);
 306                 break;
 307         default:
 308                 break;
 309         }
 310 }
 311
 312 static ssize_t lm3530_mode_get(struct device *dev,
 313                 struct device_attribute *attr, char *buf)
 314 {
 315         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 316         struct lm3530_data *drvdata;
 317         int i, len = 0;
 318
 319         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
 320         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 321                 if (drvdata->mode == mode_map[i].mode_val)
 322                         len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
 323                 else
 324                         len += sprintf(buf + len, "%s ", mode_map[i].mode);
 325
 326         len += sprintf(buf + len, "\n");
 327
 328         return len;
 329 }
 330
 331 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 332                                    *attr, const char *buf, size_t size)
 333 {
 334         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 335         struct lm3530_data *drvdata;
 336         struct lm3530_pwm_data *pwm;
 337         u8 max_brightness;
 338         int mode, err;
 339
 340         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
 341         pwm = &drvdata->pdata->pwm_data;
 342         max_brightness = led_cdev->max_brightness;
 343         mode = lm3530_get_mode_from_str(buf);
 344         if (mode < 0) {
 345                 dev_err(dev, "Invalid mode\n");
 346                 return -EINVAL;
 347         }
 348
 349         drvdata->mode = mode;
 350
 351         /* set pwm to low if unnecessary */
 352         if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
 353                 pwm->pwm_set_intensity(0, max_brightness);
 354
 355         err = lm3530_init_registers(drvdata);
 356         if (err) {
 357                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 358                 return err;
 359         }
 360
 361         return sizeof(drvdata->mode);
 362 }
 363 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
 364
 365 static int __devinit lm3530_probe(struct i2c_client *client,
 366                            const struct i2c_device_id *id)
 367 {
 368         struct lm3530_platform_data *pdata = client->dev.platform_data;
 369         struct lm3530_data *drvdata;
 370         int err = 0;
 371
 372         if (pdata == NULL) {
 373                 dev_err(&client->dev, "platform data required\n");
 374                 err = -ENODEV;
 375                 goto err_out;
 376         }
 377
 378         /* BL mode */
 379         if (pdata->mode > LM3530_BL_MODE_PWM) {
 380                 dev_err(&client->dev, "Illegal Mode request\n");
 381                 err = -EINVAL;
 382                 goto err_out;
 383         }
 384
 385         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 386                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 387                 err = -EIO;
 388                 goto err_out;
 389         }
 390
 391         drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 392         if (drvdata == NULL) {
 393                 err = -ENOMEM;
 394                 goto err_out;
 395         }
 396
 397         drvdata->mode = pdata->mode;
 398         drvdata->client = client;
 399         drvdata->pdata = pdata;
 400         drvdata->brightness = LED_OFF;
 401         drvdata->enable = false;
 402         drvdata->led_dev.name = LM3530_LED_DEV;
 403         drvdata->led_dev.brightness_set = lm3530_brightness_set;
 404         drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
 405
 406         i2c_set_clientdata(client, drvdata);
 407
 408         drvdata->regulator = regulator_get(&client->dev, "vin");
 409         if (IS_ERR(drvdata->regulator)) {
 410                 dev_err(&client->dev, "regulator get failed\n");
 411                 err = PTR_ERR(drvdata->regulator);
 412                 drvdata->regulator = NULL;
 413                 goto err_regulator_get;
 414         }
 415
 416         if (drvdata->pdata->brt_val) {
 417                 err = lm3530_init_registers(drvdata);
 418                 if (err < 0) {
 419                         dev_err(&client->dev,
 420                                 "Register Init failed: %d\n", err);
 421                         err = -ENODEV;
 422                         goto err_reg_init;
 423                 }
 424         }
 425         err = led_classdev_register(&client->dev, &drvdata->led_dev);
 426         if (err < 0) {
 427                 dev_err(&client->dev, "Register led class failed: %d\n", err);
 428                 err = -ENODEV;
 429                 goto err_class_register;
 430         }
 431
 432         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 433         if (err < 0) {
 434                 dev_err(&client->dev, "File device creation failed: %d\n", err);
 435                 err = -ENODEV;
 436                 goto err_create_file;
 437         }
 438
 439         return 0;
 440
 441 err_create_file:
 442         led_classdev_unregister(&drvdata->led_dev);
 443 err_class_register:
 444 err_reg_init:
 445         regulator_put(drvdata->regulator);
 446 err_regulator_get:
 447         kfree(drvdata);
 448 err_out:
 449         return err;
 450 }
 451
 452 static int __devexit lm3530_remove(struct i2c_client *client)
 453 {
 454         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 455
 456         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 457
 458         if (drvdata->enable)
 459                 regulator_disable(drvdata->regulator);
 460         regulator_put(drvdata->regulator);
 461         led_classdev_unregister(&drvdata->led_dev);
 462         kfree(drvdata);
 463         return 0;
 464 }
 465
 466 static const struct i2c_device_id lm3530_id[] = {
 467         {LM3530_NAME, 0},
 468         {}
 469 };
 470 MODULE_DEVICE_TABLE(i2c, lm3530_id);
 471
 472 static struct i2c_driver lm3530_i2c_driver = {
 473         .probe = lm3530_probe,
 474         .remove = __devexit_p(lm3530_remove),
 475         .id_table = lm3530_id,
 476         .driver = {
 477                 .name = LM3530_NAME,
 478                 .owner = THIS_MODULE,
 479         },
 480 };
 481
 482 module_i2c_driver(lm3530_i2c_driver);
 483
 484 MODULE_DESCRIPTION("Back Light driver for LM3530");
 485 MODULE_LICENSE("GPL v2");
 486 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");