drivers/video/backlight/lm3630a_bl.c

   1 /*
   2 * Simple driver for Texas Instruments LM3630A Backlight driver chip
   3 * Copyright (C) 2012 Texas Instruments
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 */
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12 #include <linux/i2c.h>
  13 #include <linux/backlight.h>
  14 #include <linux/err.h>
  15 #include <linux/delay.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/regmap.h>
  19 #include <linux/pwm.h>
  20 #include <linux/platform_data/lm3630a_bl.h>
  21
  22 #define REG_CTRL        0x00
  23 #define REG_BOOST       0x02
  24 #define REG_CONFIG      0x01
  25 #define REG_BRT_A       0x03
  26 #define REG_BRT_B       0x04
  27 #define REG_I_A         0x05
  28 #define REG_I_B         0x06
  29 #define REG_INT_STATUS  0x09
  30 #define REG_INT_EN      0x0A
  31 #define REG_FAULT       0x0B
  32 #define REG_PWM_OUTLOW  0x12
  33 #define REG_PWM_OUTHIGH 0x13
  34 #define REG_MAX         0x1F
  35
  36 #define INT_DEBOUNCE_MSEC       10
  37 struct lm3630a_chip {
  38         struct device *dev;
  39         struct delayed_work work;
  40
  41         int irq;
  42         struct workqueue_struct *irqthread;
  43         struct lm3630a_platform_data *pdata;
  44         struct backlight_device *bleda;
  45         struct backlight_device *bledb;
  46         struct regmap *regmap;
  47         struct pwm_device *pwmd;
  48 };
  49
  50 /* i2c access */
  51 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
  52 {
  53         int rval;
  54         unsigned int reg_val;
  55
  56         rval = regmap_read(pchip->regmap, reg, &reg_val);
  57         if (rval < 0)
  58                 return rval;
  59         return reg_val & 0xFF;
  60 }
  61
  62 static int lm3630a_write(struct lm3630a_chip *pchip,
  63                          unsigned int reg, unsigned int data)
  64 {
  65         return regmap_write(pchip->regmap, reg, data);
  66 }
  67
  68 static int lm3630a_update(struct lm3630a_chip *pchip,
  69                           unsigned int reg, unsigned int mask,
  70                           unsigned int data)
  71 {
  72         return regmap_update_bits(pchip->regmap, reg, mask, data);
  73 }
  74
  75 /* initialize chip */
  76 static int lm3630a_chip_init(struct lm3630a_chip *pchip)
  77 {
  78         int rval;
  79         struct lm3630a_platform_data *pdata = pchip->pdata;
  80
  81         usleep_range(1000, 2000);
  82         /* set Filter Strength Register */
  83         rval = lm3630a_write(pchip, 0x50, 0x03);
  84         /* set Cofig. register */
  85         rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
  86         /* set boost control */
  87         rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
  88         /* set current A */
  89         rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
  90         /* set current B */
  91         rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
  92         /* set control */
  93         rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
  94         rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
  95         usleep_range(1000, 2000);
  96         /* set brightness A and B */
  97         rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
  98         rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
  99
 100         if (rval < 0)
 101                 dev_err(pchip->dev, "i2c failed to access register\n");
 102         return rval;
 103 }
 104
 105 /* interrupt handling */
 106 static void lm3630a_delayed_func(struct work_struct *work)
 107 {
 108         int rval;
 109         struct lm3630a_chip *pchip;
 110
 111         pchip = container_of(work, struct lm3630a_chip, work.work);
 112
 113         rval = lm3630a_read(pchip, REG_INT_STATUS);
 114         if (rval < 0) {
 115                 dev_err(pchip->dev,
 116                         "i2c failed to access REG_INT_STATUS Register\n");
 117                 return;
 118         }
 119
 120         dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
 121 }
 122
 123 static irqreturn_t lm3630a_isr_func(int irq, void *chip)
 124 {
 125         int rval;
 126         struct lm3630a_chip *pchip = chip;
 127         unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
 128
 129         queue_delayed_work(pchip->irqthread, &pchip->work, delay);
 130
 131         rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
 132         if (rval < 0) {
 133                 dev_err(pchip->dev, "i2c failed to access register\n");
 134                 return IRQ_NONE;
 135         }
 136         return IRQ_HANDLED;
 137 }
 138
 139 static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 140 {
 141         int rval;
 142
 143         rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
 144         if (rval < 0)
 145                 return rval;
 146
 147         INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
 148         pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
 149         if (!pchip->irqthread) {
 150                 dev_err(pchip->dev, "create irq thread fail\n");
 151                 return -ENOMEM;
 152         }
 153         if (request_threaded_irq
 154             (pchip->irq, NULL, lm3630a_isr_func,
 155              IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
 156                 dev_err(pchip->dev, "request threaded irq fail\n");
 157                 destroy_workqueue(pchip->irqthread);
 158                 return -ENOMEM;
 159         }
 160         return rval;
 161 }
 162
 163 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 164 {
 165         unsigned int period = pwm_get_period(pchip->pwmd);
 166         unsigned int duty = br * period / br_max;
 167
 168         pwm_config(pchip->pwmd, duty, period);
 169         if (duty)
 170                 pwm_enable(pchip->pwmd);
 171         else
 172                 pwm_disable(pchip->pwmd);
 173 }
 174
 175 /* update and get brightness */
 176 static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 177 {
 178         int ret;
 179         struct lm3630a_chip *pchip = bl_get_data(bl);
 180         enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 181
 182         /* pwm control */
 183         if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
 184                 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
 185                                  bl->props.max_brightness);
 186                 return bl->props.brightness;
 187         }
 188
 189         /* disable sleep */
 190         ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
 191         if (ret < 0)
 192                 goto out_i2c_err;
 193         usleep_range(1000, 2000);
 194         /* minimum brightness is 0x04 */
 195         ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
 196         if (bl->props.brightness < 0x4)
 197                 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
 198         else
 199                 ret |= lm3630a_update(pchip, REG_CTRL,
 200                                       LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
 201         if (ret < 0)
 202                 goto out_i2c_err;
 203         return bl->props.brightness;
 204
 205 out_i2c_err:
 206         dev_err(pchip->dev, "i2c failed to access\n");
 207         return bl->props.brightness;
 208 }
 209
 210 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
 211 {
 212         int brightness, rval;
 213         struct lm3630a_chip *pchip = bl_get_data(bl);
 214         enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 215
 216         if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
 217                 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
 218                 if (rval < 0)
 219                         goto out_i2c_err;
 220                 brightness = (rval & 0x01) << 8;
 221                 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
 222                 if (rval < 0)
 223                         goto out_i2c_err;
 224                 brightness |= rval;
 225                 goto out;
 226         }
 227
 228         /* disable sleep */
 229         rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
 230         if (rval < 0)
 231                 goto out_i2c_err;
 232         usleep_range(1000, 2000);
 233         rval = lm3630a_read(pchip, REG_BRT_A);
 234         if (rval < 0)
 235                 goto out_i2c_err;
 236         brightness = rval;
 237
 238 out:
 239         bl->props.brightness = brightness;
 240         return bl->props.brightness;
 241 out_i2c_err:
 242         dev_err(pchip->dev, "i2c failed to access register\n");
 243         return 0;
 244 }
 245
 246 static const struct backlight_ops lm3630a_bank_a_ops = {
 247         .options = BL_CORE_SUSPENDRESUME,
 248         .update_status = lm3630a_bank_a_update_status,
 249         .get_brightness = lm3630a_bank_a_get_brightness,
 250 };
 251
 252 /* update and get brightness */
 253 static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 254 {
 255         int ret;
 256         struct lm3630a_chip *pchip = bl_get_data(bl);
 257         enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 258
 259         /* pwm control */
 260         if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
 261                 lm3630a_pwm_ctrl(pchip, bl->props.brightness,
 262                                  bl->props.max_brightness);
 263                 return bl->props.brightness;
 264         }
 265
 266         /* disable sleep */
 267         ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
 268         if (ret < 0)
 269                 goto out_i2c_err;
 270         usleep_range(1000, 2000);
 271         /* minimum brightness is 0x04 */
 272         ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
 273         if (bl->props.brightness < 0x4)
 274                 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
 275         else
 276                 ret |= lm3630a_update(pchip, REG_CTRL,
 277                                       LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
 278         if (ret < 0)
 279                 goto out_i2c_err;
 280         return bl->props.brightness;
 281
 282 out_i2c_err:
 283         dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
 284         return bl->props.brightness;
 285 }
 286
 287 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
 288 {
 289         int brightness, rval;
 290         struct lm3630a_chip *pchip = bl_get_data(bl);
 291         enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 292
 293         if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
 294                 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
 295                 if (rval < 0)
 296                         goto out_i2c_err;
 297                 brightness = (rval & 0x01) << 8;
 298                 rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
 299                 if (rval < 0)
 300                         goto out_i2c_err;
 301                 brightness |= rval;
 302                 goto out;
 303         }
 304
 305         /* disable sleep */
 306         rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
 307         if (rval < 0)
 308                 goto out_i2c_err;
 309         usleep_range(1000, 2000);
 310         rval = lm3630a_read(pchip, REG_BRT_B);
 311         if (rval < 0)
 312                 goto out_i2c_err;
 313         brightness = rval;
 314
 315 out:
 316         bl->props.brightness = brightness;
 317         return bl->props.brightness;
 318 out_i2c_err:
 319         dev_err(pchip->dev, "i2c failed to access register\n");
 320         return 0;
 321 }
 322
 323 static const struct backlight_ops lm3630a_bank_b_ops = {
 324         .options = BL_CORE_SUSPENDRESUME,
 325         .update_status = lm3630a_bank_b_update_status,
 326         .get_brightness = lm3630a_bank_b_get_brightness,
 327 };
 328
 329 static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
 330 {
 331         struct backlight_properties props;
 332         struct lm3630a_platform_data *pdata = pchip->pdata;
 333
 334         props.type = BACKLIGHT_RAW;
 335         if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
 336                 props.brightness = pdata->leda_init_brt;
 337                 props.max_brightness = pdata->leda_max_brt;
 338                 pchip->bleda =
 339                     devm_backlight_device_register(pchip->dev, "lm3630a_leda",
 340                                                    pchip->dev, pchip,
 341                                                    &lm3630a_bank_a_ops, &props);
 342                 if (IS_ERR(pchip->bleda))
 343                         return PTR_ERR(pchip->bleda);
 344         }
 345
 346         if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
 347             (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
 348                 props.brightness = pdata->ledb_init_brt;
 349                 props.max_brightness = pdata->ledb_max_brt;
 350                 pchip->bledb =
 351                     devm_backlight_device_register(pchip->dev, "lm3630a_ledb",
 352                                                    pchip->dev, pchip,
 353                                                    &lm3630a_bank_b_ops, &props);
 354                 if (IS_ERR(pchip->bledb))
 355                         return PTR_ERR(pchip->bledb);
 356         }
 357         return 0;
 358 }
 359
 360 static const struct regmap_config lm3630a_regmap = {
 361         .reg_bits = 8,
 362         .val_bits = 8,
 363         .max_register = REG_MAX,
 364 };
 365
 366 static int lm3630a_probe(struct i2c_client *client,
 367                          const struct i2c_device_id *id)
 368 {
 369         struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
 370         struct lm3630a_chip *pchip;
 371         int rval;
 372
 373         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 374                 dev_err(&client->dev, "fail : i2c functionality check\n");
 375                 return -EOPNOTSUPP;
 376         }
 377
 378         pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
 379                              GFP_KERNEL);
 380         if (!pchip)
 381                 return -ENOMEM;
 382         pchip->dev = &client->dev;
 383
 384         pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
 385         if (IS_ERR(pchip->regmap)) {
 386                 rval = PTR_ERR(pchip->regmap);
 387                 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
 388                 return rval;
 389         }
 390
 391         i2c_set_clientdata(client, pchip);
 392         if (pdata == NULL) {
 393                 pdata = devm_kzalloc(pchip->dev,
 394                                      sizeof(struct lm3630a_platform_data),
 395                                      GFP_KERNEL);
 396                 if (pdata == NULL)
 397                         return -ENOMEM;
 398                 /* default values */
 399                 pdata->leda_ctrl = LM3630A_LEDA_ENABLE;
 400                 pdata->ledb_ctrl = LM3630A_LEDB_ENABLE;
 401                 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
 402                 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
 403                 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
 404                 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
 405         }
 406         pchip->pdata = pdata;
 407
 408         /* chip initialize */
 409         rval = lm3630a_chip_init(pchip);
 410         if (rval < 0) {
 411                 dev_err(&client->dev, "fail : init chip\n");
 412                 return rval;
 413         }
 414         /* backlight register */
 415         rval = lm3630a_backlight_register(pchip);
 416         if (rval < 0) {
 417                 dev_err(&client->dev, "fail : backlight register.\n");
 418                 return rval;
 419         }
 420         /* pwm */
 421         if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
 422                 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
 423                 if (IS_ERR(pchip->pwmd)) {
 424                         dev_err(&client->dev, "fail : get pwm device\n");
 425                         return PTR_ERR(pchip->pwmd);
 426                 }
 427         }
 428         pchip->pwmd->period = pdata->pwm_period;
 429
 430         /* interrupt enable  : irq 0 is not allowed */
 431         pchip->irq = client->irq;
 432         if (pchip->irq) {
 433                 rval = lm3630a_intr_config(pchip);
 434                 if (rval < 0)
 435                         return rval;
 436         }
 437         dev_info(&client->dev, "LM3630A backlight register OK.\n");
 438         return 0;
 439 }
 440
 441 static int lm3630a_remove(struct i2c_client *client)
 442 {
 443         int rval;
 444         struct lm3630a_chip *pchip = i2c_get_clientdata(client);
 445
 446         rval = lm3630a_write(pchip, REG_BRT_A, 0);
 447         if (rval < 0)
 448                 dev_err(pchip->dev, "i2c failed to access register\n");
 449
 450         rval = lm3630a_write(pchip, REG_BRT_B, 0);
 451         if (rval < 0)
 452                 dev_err(pchip->dev, "i2c failed to access register\n");
 453
 454         if (pchip->irq) {
 455                 free_irq(pchip->irq, pchip);
 456                 flush_workqueue(pchip->irqthread);
 457                 destroy_workqueue(pchip->irqthread);
 458         }
 459         return 0;
 460 }
 461
 462 static const struct i2c_device_id lm3630a_id[] = {
 463         {LM3630A_NAME, 0},
 464         {}
 465 };
 466
 467 MODULE_DEVICE_TABLE(i2c, lm3630a_id);
 468
 469 static struct i2c_driver lm3630a_i2c_driver = {
 470         .driver = {
 471                    .name = LM3630A_NAME,
 472                    },
 473         .probe = lm3630a_probe,
 474         .remove = lm3630a_remove,
 475         .id_table = lm3630a_id,
 476 };
 477
 478 module_i2c_driver(lm3630a_i2c_driver);
 479
 480 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
 481 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
 482 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
 483 MODULE_LICENSE("GPL v2");