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
  21 #define LM3530_LED_DEV "lcd-backlight"
  22 #define LM3530_NAME "lm3530-led"
  23
  24 #define LM3530_GEN_CONFIG               0x10
  25 #define LM3530_ALS_CONFIG               0x20
  26 #define LM3530_BRT_RAMP_RATE            0x30
  27 #define LM3530_ALS_ZONE_REG             0x40
  28 #define LM3530_ALS_IMP_SELECT           0x41
  29 #define LM3530_BRT_CTRL_REG             0xA0
  30 #define LM3530_ALS_ZB0_REG              0x60
  31 #define LM3530_ALS_ZB1_REG              0x61
  32 #define LM3530_ALS_ZB2_REG              0x62
  33 #define LM3530_ALS_ZB3_REG              0x63
  34 #define LM3530_ALS_Z0T_REG              0x70
  35 #define LM3530_ALS_Z1T_REG              0x71
  36 #define LM3530_ALS_Z2T_REG              0x72
  37 #define LM3530_ALS_Z3T_REG              0x73
  38 #define LM3530_ALS_Z4T_REG              0x74
  39 #define LM3530_REG_MAX                  15
  40
  41 /* General Control Register */
  42 #define LM3530_EN_I2C_SHIFT             (0)
  43 #define LM3530_RAMP_LAW_SHIFT           (1)
  44 #define LM3530_MAX_CURR_SHIFT           (2)
  45 #define LM3530_EN_PWM_SHIFT             (5)
  46 #define LM3530_PWM_POL_SHIFT            (6)
  47 #define LM3530_EN_PWM_SIMPLE_SHIFT      (7)
  48
  49 #define LM3530_ENABLE_I2C               (1 << LM3530_EN_I2C_SHIFT)
  50 #define LM3530_ENABLE_PWM               (1 << LM3530_EN_PWM_SHIFT)
  51 #define LM3530_POL_LOW                  (1 << LM3530_PWM_POL_SHIFT)
  52 #define LM3530_ENABLE_PWM_SIMPLE        (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
  53
  54 /* ALS Config Register Options */
  55 #define LM3530_ALS_AVG_TIME_SHIFT       (0)
  56 #define LM3530_EN_ALS_SHIFT             (3)
  57 #define LM3530_ALS_SEL_SHIFT            (5)
  58
  59 #define LM3530_ENABLE_ALS               (3 << LM3530_EN_ALS_SHIFT)
  60
  61 /* Brightness Ramp Rate Register */
  62 #define LM3530_BRT_RAMP_FALL_SHIFT      (0)
  63 #define LM3530_BRT_RAMP_RISE_SHIFT      (3)
  64
  65 /* ALS Resistor Select */
  66 #define LM3530_ALS1_IMP_SHIFT           (0)
  67 #define LM3530_ALS2_IMP_SHIFT           (4)
  68
  69 /* Zone Boundary Register defaults */
  70 #define LM3530_DEF_ZB_0                 (0x33)
  71 #define LM3530_DEF_ZB_1                 (0x66)
  72 #define LM3530_DEF_ZB_2                 (0x99)
  73 #define LM3530_DEF_ZB_3                 (0xCC)
  74
  75 /* Zone Target Register defaults */
  76 #define LM3530_DEF_ZT_0                 (0x19)
  77 #define LM3530_DEF_ZT_1                 (0x33)
  78 #define LM3530_DEF_ZT_2                 (0x4C)
  79 #define LM3530_DEF_ZT_3                 (0x66)
  80 #define LM3530_DEF_ZT_4                 (0x7F)
  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  */
 100 struct lm3530_data {
 101         struct led_classdev led_dev;
 102         struct i2c_client *client;
 103         struct lm3530_platform_data *pdata;
 104         enum lm3530_mode mode;
 105 };
 106
 107 static const u8 lm3530_reg[LM3530_REG_MAX] = {
 108         LM3530_GEN_CONFIG,
 109         LM3530_ALS_CONFIG,
 110         LM3530_BRT_RAMP_RATE,
 111         LM3530_ALS_ZONE_REG,
 112         LM3530_ALS_IMP_SELECT,
 113         LM3530_BRT_CTRL_REG,
 114         LM3530_ALS_ZB0_REG,
 115         LM3530_ALS_ZB1_REG,
 116         LM3530_ALS_ZB2_REG,
 117         LM3530_ALS_ZB3_REG,
 118         LM3530_ALS_Z0T_REG,
 119         LM3530_ALS_Z1T_REG,
 120         LM3530_ALS_Z2T_REG,
 121         LM3530_ALS_Z3T_REG,
 122         LM3530_ALS_Z4T_REG,
 123 };
 124
 125 static int lm3530_get_mode_from_str(const char *str)
 126 {
 127         int i;
 128
 129         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 130                 if (sysfs_streq(str, mode_map[i].mode))
 131                         return mode_map[i].mode_val;
 132
 133         return -1;
 134 }
 135
 136 static int lm3530_init_registers(struct lm3530_data *drvdata)
 137 {
 138         int ret = 0;
 139         int i;
 140         u8 gen_config;
 141         u8 als_config = 0;
 142         u8 brt_ramp;
 143         u8 als_imp_sel = 0;
 144         u8 brightness;
 145         u8 reg_val[LM3530_REG_MAX];
 146         struct lm3530_platform_data *pltfm = drvdata->pdata;
 147         struct i2c_client *client = drvdata->client;
 148
 149         gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 150                         ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
 151
 152         if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
 153             drvdata->mode == LM3530_BL_MODE_ALS)
 154                 gen_config |= (LM3530_ENABLE_I2C);
 155
 156         if (drvdata->mode == LM3530_BL_MODE_ALS) {
 157                 als_config =
 158                         (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 159                         (LM3530_ENABLE_ALS) |
 160                         (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
 161
 162                 als_imp_sel =
 163                         (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 164                         (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 165         }
 166
 167         if (drvdata->mode == LM3530_BL_MODE_PWM)
 168                 gen_config |= (LM3530_ENABLE_PWM) |
 169                                 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
 170                                 (LM3530_ENABLE_PWM_SIMPLE);
 171
 172         brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 173                         (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 174
 175         brightness = pltfm->brt_val;
 176
 177         reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
 178         reg_val[1] = als_config;        /* LM3530_ALS_CONFIG */
 179         reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
 180         reg_val[3] = 0x00;              /* LM3530_ALS_ZONE_REG */
 181         reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
 182         reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
 183         reg_val[6] = LM3530_DEF_ZB_0;   /* LM3530_ALS_ZB0_REG */
 184         reg_val[7] = LM3530_DEF_ZB_1;   /* LM3530_ALS_ZB1_REG */
 185         reg_val[8] = LM3530_DEF_ZB_2;   /* LM3530_ALS_ZB2_REG */
 186         reg_val[9] = LM3530_DEF_ZB_3;   /* LM3530_ALS_ZB3_REG */
 187         reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
 188         reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
 189         reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
 190         reg_val[13] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
 191         reg_val[14] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
 192
 193         for (i = 0; i < LM3530_REG_MAX; i++) {
 194                 ret = i2c_smbus_write_byte_data(client,
 195                                 lm3530_reg[i], reg_val[i]);
 196                 if (ret)
 197                         break;
 198         }
 199
 200         return ret;
 201 }
 202
 203 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 204                                      enum led_brightness brt_val)
 205 {
 206         int err;
 207         struct lm3530_data *drvdata =
 208             container_of(led_cdev, struct lm3530_data, led_dev);
 209
 210         switch (drvdata->mode) {
 211         case LM3530_BL_MODE_MANUAL:
 212
 213                 /* set the brightness in brightness control register*/
 214                 err = i2c_smbus_write_byte_data(drvdata->client,
 215                                 LM3530_BRT_CTRL_REG, brt_val / 2);
 216                 if (err)
 217                         dev_err(&drvdata->client->dev,
 218                                 "Unable to set brightness: %d\n", err);
 219                 break;
 220         case LM3530_BL_MODE_ALS:
 221                 break;
 222         case LM3530_BL_MODE_PWM:
 223                 break;
 224         default:
 225                 break;
 226         }
 227 }
 228
 229
 230 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 231                                    *attr, const char *buf, size_t size)
 232 {
 233         int err;
 234         struct i2c_client *client = container_of(
 235                                         dev->parent, struct i2c_client, dev);
 236         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 237         int mode;
 238
 239         mode = lm3530_get_mode_from_str(buf);
 240         if (mode < 0) {
 241                 dev_err(dev, "Invalid mode\n");
 242                 return -EINVAL;
 243         }
 244
 245         if (mode == LM3530_BL_MODE_MANUAL)
 246                 drvdata->mode = LM3530_BL_MODE_MANUAL;
 247         else if (mode == LM3530_BL_MODE_ALS)
 248                 drvdata->mode = LM3530_BL_MODE_ALS;
 249         else if (mode == LM3530_BL_MODE_PWM) {
 250                 dev_err(dev, "PWM mode not supported\n");
 251                 return -EINVAL;
 252         }
 253
 254         err = lm3530_init_registers(drvdata);
 255         if (err) {
 256                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 257                 return err;
 258         }
 259
 260         return sizeof(drvdata->mode);
 261 }
 262
 263 static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
 264
 265 static int __devinit lm3530_probe(struct i2c_client *client,
 266                            const struct i2c_device_id *id)
 267 {
 268         struct lm3530_platform_data *pdata = client->dev.platform_data;
 269         struct lm3530_data *drvdata;
 270         int err = 0;
 271
 272         if (pdata == NULL) {
 273                 dev_err(&client->dev, "platform data required\n");
 274                 err = -ENODEV;
 275                 goto err_out;
 276         }
 277
 278         /* BL mode */
 279         if (pdata->mode > LM3530_BL_MODE_PWM) {
 280                 dev_err(&client->dev, "Illegal Mode request\n");
 281                 err = -EINVAL;
 282                 goto err_out;
 283         }
 284
 285         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 286                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 287                 err = -EIO;
 288                 goto err_out;
 289         }
 290
 291         drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 292         if (drvdata == NULL) {
 293                 err = -ENOMEM;
 294                 goto err_out;
 295         }
 296
 297         drvdata->mode = pdata->mode;
 298         drvdata->client = client;
 299         drvdata->pdata = pdata;
 300         drvdata->led_dev.name = LM3530_LED_DEV;
 301         drvdata->led_dev.brightness_set = lm3530_brightness_set;
 302
 303         i2c_set_clientdata(client, drvdata);
 304
 305         err = lm3530_init_registers(drvdata);
 306         if (err < 0) {
 307                 dev_err(&client->dev, "Register Init failed: %d\n", err);
 308                 err = -ENODEV;
 309                 goto err_reg_init;
 310         }
 311
 312         err = led_classdev_register((struct device *)
 313                                       &client->dev, &drvdata->led_dev);
 314         if (err < 0) {
 315                 dev_err(&client->dev, "Register led class failed: %d\n", err);
 316                 err = -ENODEV;
 317                 goto err_class_register;
 318         }
 319
 320         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 321         if (err < 0) {
 322                 dev_err(&client->dev, "File device creation failed: %d\n", err);
 323                 err = -ENODEV;
 324                 goto err_create_file;
 325         }
 326
 327         return 0;
 328
 329 err_create_file:
 330         led_classdev_unregister(&drvdata->led_dev);
 331 err_class_register:
 332 err_reg_init:
 333         kfree(drvdata);
 334 err_out:
 335         return err;
 336 }
 337
 338 static int __devexit lm3530_remove(struct i2c_client *client)
 339 {
 340         struct lm3530_data *drvdata = i2c_get_clientdata(client);
 341
 342         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 343         led_classdev_unregister(&drvdata->led_dev);
 344         kfree(drvdata);
 345         return 0;
 346 }
 347
 348 static const struct i2c_device_id lm3530_id[] = {
 349         {LM3530_NAME, 0},
 350         {}
 351 };
 352 MODULE_DEVICE_TABLE(i2c, lm3530_id);
 353
 354 static struct i2c_driver lm3530_i2c_driver = {
 355         .probe = lm3530_probe,
 356         .remove = lm3530_remove,
 357         .id_table = lm3530_id,
 358         .driver = {
 359                 .name = LM3530_NAME,
 360                 .owner = THIS_MODULE,
 361         },
 362 };
 363
 364 static int __init lm3530_init(void)
 365 {
 366         return i2c_add_driver(&lm3530_i2c_driver);
 367 }
 368
 369 static void __exit lm3530_exit(void)
 370 {
 371         i2c_del_driver(&lm3530_i2c_driver);
 372 }
 373
 374 module_init(lm3530_init);
 375 module_exit(lm3530_exit);
 376
 377 MODULE_DESCRIPTION("Back Light driver for LM3530");
 378 MODULE_LICENSE("GPL v2");
 379 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");