drivers/video/backlight/lm3630_bl.c

   1 /*
   2 * Simple driver for Texas Instruments LM3630 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/platform_data/lm3630_bl.h>
  20
  21 #define REG_CTRL        0x00
  22 #define REG_CONFIG      0x01
  23 #define REG_BRT_A       0x03
  24 #define REG_BRT_B       0x04
  25 #define REG_INT_STATUS  0x09
  26 #define REG_INT_EN      0x0A
  27 #define REG_FAULT       0x0B
  28 #define REG_PWM_OUTLOW  0x12
  29 #define REG_PWM_OUTHIGH 0x13
  30 #define REG_MAX         0x1F
  31
  32 #define INT_DEBOUNCE_MSEC       10
  33
  34 enum lm3630_leds {
  35         BLED_ALL = 0,
  36         BLED_1,
  37         BLED_2
  38 };
  39
  40 static const char *bled_name[] = {
  41         [BLED_ALL] = "lm3630_bled",     /*Bank1 controls all string */
  42         [BLED_1] = "lm3630_bled1",      /*Bank1 controls bled1 */
  43         [BLED_2] = "lm3630_bled2",      /*Bank1 or 2 controls bled2 */
  44 };
  45
  46 struct lm3630_chip_data {
  47         struct device *dev;
  48         struct delayed_work work;
  49         int irq;
  50         struct workqueue_struct *irqthread;
  51         struct lm3630_platform_data *pdata;
  52         struct backlight_device *bled1;
  53         struct backlight_device *bled2;
  54         struct regmap *regmap;
  55 };
  56
  57 /* initialize chip */
  58 static int lm3630_chip_init(struct lm3630_chip_data *pchip)
  59 {
  60         int ret;
  61         unsigned int reg_val;
  62         struct lm3630_platform_data *pdata = pchip->pdata;
  63
  64         /*pwm control */
  65         reg_val = ((pdata->pwm_active & 0x01) << 2) | (pdata->pwm_ctrl & 0x03);
  66         ret = regmap_update_bits(pchip->regmap, REG_CONFIG, 0x07, reg_val);
  67         if (ret < 0)
  68                 goto out;
  69
  70         /* bank control */
  71         reg_val = ((pdata->bank_b_ctrl & 0x01) << 1) |
  72                         (pdata->bank_a_ctrl & 0x07);
  73         ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x07, reg_val);
  74         if (ret < 0)
  75                 goto out;
  76
  77         ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
  78         if (ret < 0)
  79                 goto out;
  80
  81         /* set initial brightness */
  82         if (pdata->bank_a_ctrl != BANK_A_CTRL_DISABLE) {
  83                 ret = regmap_write(pchip->regmap,
  84                                    REG_BRT_A, pdata->init_brt_led1);
  85                 if (ret < 0)
  86                         goto out;
  87         }
  88
  89         if (pdata->bank_b_ctrl != BANK_B_CTRL_DISABLE) {
  90                 ret = regmap_write(pchip->regmap,
  91                                    REG_BRT_B, pdata->init_brt_led2);
  92                 if (ret < 0)
  93                         goto out;
  94         }
  95         return ret;
  96
  97 out:
  98         dev_err(pchip->dev, "i2c failed to access register\n");
  99         return ret;
 100 }
 101
 102 /* interrupt handling */
 103 static void lm3630_delayed_func(struct work_struct *work)
 104 {
 105         int ret;
 106         unsigned int reg_val;
 107         struct lm3630_chip_data *pchip;
 108
 109         pchip = container_of(work, struct lm3630_chip_data, work.work);
 110
 111         ret = regmap_read(pchip->regmap, REG_INT_STATUS, &reg_val);
 112         if (ret < 0) {
 113                 dev_err(pchip->dev,
 114                         "i2c failed to access REG_INT_STATUS Register\n");
 115                 return;
 116         }
 117
 118         dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", reg_val);
 119 }
 120
 121 static irqreturn_t lm3630_isr_func(int irq, void *chip)
 122 {
 123         int ret;
 124         struct lm3630_chip_data *pchip = chip;
 125         unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
 126
 127         queue_delayed_work(pchip->irqthread, &pchip->work, delay);
 128
 129         ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
 130         if (ret < 0)
 131                 goto out;
 132
 133         return IRQ_HANDLED;
 134 out:
 135         dev_err(pchip->dev, "i2c failed to access register\n");
 136         return IRQ_HANDLED;
 137 }
 138
 139 static int lm3630_intr_config(struct lm3630_chip_data *pchip)
 140 {
 141         INIT_DELAYED_WORK(&pchip->work, lm3630_delayed_func);
 142         pchip->irqthread = create_singlethread_workqueue("lm3630-irqthd");
 143         if (!pchip->irqthread) {
 144                 dev_err(pchip->dev, "create irq thread fail...\n");
 145                 return -1;
 146         }
 147         if (request_threaded_irq
 148             (pchip->irq, NULL, lm3630_isr_func,
 149              IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630_irq", pchip)) {
 150                 dev_err(pchip->dev, "request threaded irq fail..\n");
 151                 return -1;
 152         }
 153         return 0;
 154 }
 155
 156 static bool
 157 set_intensity(struct backlight_device *bl, struct lm3630_chip_data *pchip)
 158 {
 159         if (!pchip->pdata->pwm_set_intensity)
 160                 return false;
 161         pchip->pdata->pwm_set_intensity(bl->props.brightness - 1,
 162                                         pchip->pdata->pwm_period);
 163         return true;
 164 }
 165
 166 /* update and get brightness */
 167 static int lm3630_bank_a_update_status(struct backlight_device *bl)
 168 {
 169         int ret;
 170         struct lm3630_chip_data *pchip = bl_get_data(bl);
 171         enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 172
 173         /* brightness 0 means disable */
 174         if (!bl->props.brightness) {
 175                 ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x04, 0x00);
 176                 if (ret < 0)
 177                         goto out;
 178                 return bl->props.brightness;
 179         }
 180
 181         /* pwm control */
 182         if (pwm_ctrl == PWM_CTRL_BANK_A || pwm_ctrl == PWM_CTRL_BANK_ALL) {
 183                 if (!set_intensity(bl, pchip))
 184                         dev_err(pchip->dev, "No pwm control func. in plat-data\n");
 185         } else {
 186
 187                 /* i2c control */
 188                 ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
 189                 if (ret < 0)
 190                         goto out;
 191                 mdelay(1);
 192                 ret = regmap_write(pchip->regmap,
 193                                    REG_BRT_A, bl->props.brightness - 1);
 194                 if (ret < 0)
 195                         goto out;
 196         }
 197         return bl->props.brightness;
 198 out:
 199         dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
 200         return bl->props.brightness;
 201 }
 202
 203 static int lm3630_bank_a_get_brightness(struct backlight_device *bl)
 204 {
 205         unsigned int reg_val;
 206         int brightness, ret;
 207         struct lm3630_chip_data *pchip = bl_get_data(bl);
 208         enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 209
 210         if (pwm_ctrl == PWM_CTRL_BANK_A || pwm_ctrl == PWM_CTRL_BANK_ALL) {
 211                 ret = regmap_read(pchip->regmap, REG_PWM_OUTHIGH, &reg_val);
 212                 if (ret < 0)
 213                         goto out;
 214                 brightness = reg_val & 0x01;
 215                 ret = regmap_read(pchip->regmap, REG_PWM_OUTLOW, &reg_val);
 216                 if (ret < 0)
 217                         goto out;
 218                 brightness = ((brightness << 8) | reg_val) + 1;
 219         } else {
 220                 ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
 221                 if (ret < 0)
 222                         goto out;
 223                 mdelay(1);
 224                 ret = regmap_read(pchip->regmap, REG_BRT_A, &reg_val);
 225                 if (ret < 0)
 226                         goto out;
 227                 brightness = reg_val + 1;
 228         }
 229         bl->props.brightness = brightness;
 230         return bl->props.brightness;
 231 out:
 232         dev_err(pchip->dev, "i2c failed to access register\n");
 233         return 0;
 234 }
 235
 236 static const struct backlight_ops lm3630_bank_a_ops = {
 237         .options = BL_CORE_SUSPENDRESUME,
 238         .update_status = lm3630_bank_a_update_status,
 239         .get_brightness = lm3630_bank_a_get_brightness,
 240 };
 241
 242 static int lm3630_bank_b_update_status(struct backlight_device *bl)
 243 {
 244         int ret;
 245         struct lm3630_chip_data *pchip = bl_get_data(bl);
 246         enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 247
 248         if (pwm_ctrl == PWM_CTRL_BANK_B || pwm_ctrl == PWM_CTRL_BANK_ALL) {
 249                 if (!set_intensity(bl, pchip))
 250                         dev_err(pchip->dev,
 251                                 "no pwm control func. in plat-data\n");
 252         } else {
 253                 ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
 254                 if (ret < 0)
 255                         goto out;
 256                 mdelay(1);
 257                 ret = regmap_write(pchip->regmap,
 258                                    REG_BRT_B, bl->props.brightness - 1);
 259         }
 260         return bl->props.brightness;
 261 out:
 262         dev_err(pchip->dev, "i2c failed to access register\n");
 263         return bl->props.brightness;
 264 }
 265
 266 static int lm3630_bank_b_get_brightness(struct backlight_device *bl)
 267 {
 268         unsigned int reg_val;
 269         int brightness, ret;
 270         struct lm3630_chip_data *pchip = bl_get_data(bl);
 271         enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 272
 273         if (pwm_ctrl == PWM_CTRL_BANK_B || pwm_ctrl == PWM_CTRL_BANK_ALL) {
 274                 ret = regmap_read(pchip->regmap, REG_PWM_OUTHIGH, &reg_val);
 275                 if (ret < 0)
 276                         goto out;
 277                 brightness = reg_val & 0x01;
 278                 ret = regmap_read(pchip->regmap, REG_PWM_OUTLOW, &reg_val);
 279                 if (ret < 0)
 280                         goto out;
 281                 brightness = ((brightness << 8) | reg_val) + 1;
 282         } else {
 283                 ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
 284                 if (ret < 0)
 285                         goto out;
 286                 mdelay(1);
 287                 ret = regmap_read(pchip->regmap, REG_BRT_B, &reg_val);
 288                 if (ret < 0)
 289                         goto out;
 290                 brightness = reg_val + 1;
 291         }
 292         bl->props.brightness = brightness;
 293
 294         return bl->props.brightness;
 295 out:
 296         dev_err(pchip->dev, "i2c failed to access register\n");
 297         return bl->props.brightness;
 298 }
 299
 300 static const struct backlight_ops lm3630_bank_b_ops = {
 301         .options = BL_CORE_SUSPENDRESUME,
 302         .update_status = lm3630_bank_b_update_status,
 303         .get_brightness = lm3630_bank_b_get_brightness,
 304 };
 305
 306 static int lm3630_backlight_register(struct lm3630_chip_data *pchip,
 307                                      enum lm3630_leds ledno)
 308 {
 309         const char *name = bled_name[ledno];
 310         struct backlight_properties props;
 311         struct lm3630_platform_data *pdata = pchip->pdata;
 312
 313         props.type = BACKLIGHT_RAW;
 314         switch (ledno) {
 315         case BLED_1:
 316         case BLED_ALL:
 317                 props.brightness = pdata->init_brt_led1;
 318                 props.max_brightness = pdata->max_brt_led1;
 319                 pchip->bled1 =
 320                     backlight_device_register(name, pchip->dev, pchip,
 321                                               &lm3630_bank_a_ops, &props);
 322                 if (IS_ERR(pchip->bled1))
 323                         return -EIO;
 324                 break;
 325         case BLED_2:
 326                 props.brightness = pdata->init_brt_led2;
 327                 props.max_brightness = pdata->max_brt_led2;
 328                 pchip->bled2 =
 329                     backlight_device_register(name, pchip->dev, pchip,
 330                                               &lm3630_bank_b_ops, &props);
 331                 if (IS_ERR(pchip->bled2))
 332                         return -EIO;
 333                 break;
 334         }
 335         return 0;
 336 }
 337
 338 static void lm3630_backlight_unregister(struct lm3630_chip_data *pchip)
 339 {
 340         if (pchip->bled1)
 341                 backlight_device_unregister(pchip->bled1);
 342         if (pchip->bled2)
 343                 backlight_device_unregister(pchip->bled2);
 344 }
 345
 346 static const struct regmap_config lm3630_regmap = {
 347         .reg_bits = 8,
 348         .val_bits = 8,
 349         .max_register = REG_MAX,
 350 };
 351
 352 static int lm3630_probe(struct i2c_client *client,
 353                                   const struct i2c_device_id *id)
 354 {
 355         struct lm3630_platform_data *pdata = client->dev.platform_data;
 356         struct lm3630_chip_data *pchip;
 357         int ret;
 358
 359         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 360                 dev_err(&client->dev, "fail : i2c functionality check...\n");
 361                 return -EOPNOTSUPP;
 362         }
 363
 364         if (pdata == NULL) {
 365                 dev_err(&client->dev, "fail : no platform data.\n");
 366                 return -ENODATA;
 367         }
 368
 369         pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630_chip_data),
 370                              GFP_KERNEL);
 371         if (!pchip)
 372                 return -ENOMEM;
 373         pchip->pdata = pdata;
 374         pchip->dev = &client->dev;
 375
 376         pchip->regmap = devm_regmap_init_i2c(client, &lm3630_regmap);
 377         if (IS_ERR(pchip->regmap)) {
 378                 ret = PTR_ERR(pchip->regmap);
 379                 dev_err(&client->dev, "fail : allocate register map: %d\n",
 380                         ret);
 381                 return ret;
 382         }
 383         i2c_set_clientdata(client, pchip);
 384
 385         /* chip initialize */
 386         ret = lm3630_chip_init(pchip);
 387         if (ret < 0) {
 388                 dev_err(&client->dev, "fail : init chip\n");
 389                 goto err_chip_init;
 390         }
 391
 392         switch (pdata->bank_a_ctrl) {
 393         case BANK_A_CTRL_ALL:
 394                 ret = lm3630_backlight_register(pchip, BLED_ALL);
 395                 pdata->bank_b_ctrl = BANK_B_CTRL_DISABLE;
 396                 break;
 397         case BANK_A_CTRL_LED1:
 398                 ret = lm3630_backlight_register(pchip, BLED_1);
 399                 break;
 400         case BANK_A_CTRL_LED2:
 401                 ret = lm3630_backlight_register(pchip, BLED_2);
 402                 pdata->bank_b_ctrl = BANK_B_CTRL_DISABLE;
 403                 break;
 404         default:
 405                 break;
 406         }
 407
 408         if (ret < 0)
 409                 goto err_bl_reg;
 410
 411         if (pdata->bank_b_ctrl && pchip->bled2 == NULL) {
 412                 ret = lm3630_backlight_register(pchip, BLED_2);
 413                 if (ret < 0)
 414                         goto err_bl_reg;
 415         }
 416
 417         /* interrupt enable  : irq 0 is not allowed for lm3630 */
 418         pchip->irq = client->irq;
 419         if (pchip->irq)
 420                 lm3630_intr_config(pchip);
 421
 422         dev_info(&client->dev, "LM3630 backlight register OK.\n");
 423         return 0;
 424
 425 err_bl_reg:
 426         dev_err(&client->dev, "fail : backlight register.\n");
 427         lm3630_backlight_unregister(pchip);
 428 err_chip_init:
 429         return ret;
 430 }
 431
 432 static int lm3630_remove(struct i2c_client *client)
 433 {
 434         int ret;
 435         struct lm3630_chip_data *pchip = i2c_get_clientdata(client);
 436
 437         ret = regmap_write(pchip->regmap, REG_BRT_A, 0);
 438         if (ret < 0)
 439                 dev_err(pchip->dev, "i2c failed to access register\n");
 440
 441         ret = regmap_write(pchip->regmap, REG_BRT_B, 0);
 442         if (ret < 0)
 443                 dev_err(pchip->dev, "i2c failed to access register\n");
 444
 445         lm3630_backlight_unregister(pchip);
 446         if (pchip->irq) {
 447                 free_irq(pchip->irq, pchip);
 448                 flush_workqueue(pchip->irqthread);
 449                 destroy_workqueue(pchip->irqthread);
 450         }
 451         return 0;
 452 }
 453
 454 static const struct i2c_device_id lm3630_id[] = {
 455         {LM3630_NAME, 0},
 456         {}
 457 };
 458
 459 MODULE_DEVICE_TABLE(i2c, lm3630_id);
 460
 461 static struct i2c_driver lm3630_i2c_driver = {
 462         .driver = {
 463                    .name = LM3630_NAME,
 464                    },
 465         .probe = lm3630_probe,
 466         .remove = lm3630_remove,
 467         .id_table = lm3630_id,
 468 };
 469
 470 module_i2c_driver(lm3630_i2c_driver);
 471
 472 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630");
 473 MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
 474 MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
 475 MODULE_LICENSE("GPL v2");