kernel/drivers/video/backlight/lm3533_bl.c

   1 /*
   2  * lm3533-bl.c -- LM3533 Backlight driver
   3  *
   4  * Copyright (C) 2011-2012 Texas Instruments
   5  *
   6  * Author: Johan Hovold <jhovold@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under  the terms of the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/backlight.h>
  18 #include <linux/fb.h>
  19 #include <linux/slab.h>
  20
  21 #include <linux/mfd/lm3533.h>
  22
  23
  24 #define LM3533_HVCTRLBANK_COUNT         2
  25 #define LM3533_BL_MAX_BRIGHTNESS        255
  26
  27 #define LM3533_REG_CTRLBANK_AB_BCONF    0x1a
  28
  29
  30 struct lm3533_bl {
  31         struct lm3533 *lm3533;
  32         struct lm3533_ctrlbank cb;
  33         struct backlight_device *bd;
  34         int id;
  35 };
  36
  37
  38 static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
  39 {
  40         return bl->id;
  41 }
  42
  43 static int lm3533_bl_update_status(struct backlight_device *bd)
  44 {
  45         struct lm3533_bl *bl = bl_get_data(bd);
  46         int brightness = bd->props.brightness;
  47
  48         if (bd->props.power != FB_BLANK_UNBLANK)
  49                 brightness = 0;
  50         if (bd->props.fb_blank != FB_BLANK_UNBLANK)
  51                 brightness = 0;
  52
  53         return lm3533_ctrlbank_set_brightness(&bl->cb, (u8)brightness);
  54 }
  55
  56 static int lm3533_bl_get_brightness(struct backlight_device *bd)
  57 {
  58         struct lm3533_bl *bl = bl_get_data(bd);
  59         u8 val;
  60         int ret;
  61
  62         ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
  63         if (ret)
  64                 return ret;
  65
  66         return val;
  67 }
  68
  69 static const struct backlight_ops lm3533_bl_ops = {
  70         .get_brightness = lm3533_bl_get_brightness,
  71         .update_status  = lm3533_bl_update_status,
  72 };
  73
  74 static ssize_t show_id(struct device *dev,
  75                                 struct device_attribute *attr, char *buf)
  76 {
  77         struct lm3533_bl *bl = dev_get_drvdata(dev);
  78
  79         return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
  80 }
  81
  82 static ssize_t show_als_channel(struct device *dev,
  83                                 struct device_attribute *attr, char *buf)
  84 {
  85         struct lm3533_bl *bl = dev_get_drvdata(dev);
  86         unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
  87
  88         return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
  89 }
  90
  91 static ssize_t show_als_en(struct device *dev,
  92                                 struct device_attribute *attr, char *buf)
  93 {
  94         struct lm3533_bl *bl = dev_get_drvdata(dev);
  95         int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
  96         u8 val;
  97         u8 mask;
  98         bool enable;
  99         int ret;
 100
 101         ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
 102         if (ret)
 103                 return ret;
 104
 105         mask = 1 << (2 * ctrlbank);
 106         enable = val & mask;
 107
 108         return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
 109 }
 110
 111 static ssize_t store_als_en(struct device *dev,
 112                                         struct device_attribute *attr,
 113                                         const char *buf, size_t len)
 114 {
 115         struct lm3533_bl *bl = dev_get_drvdata(dev);
 116         int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
 117         int enable;
 118         u8 val;
 119         u8 mask;
 120         int ret;
 121
 122         if (kstrtoint(buf, 0, &enable))
 123                 return -EINVAL;
 124
 125         mask = 1 << (2 * ctrlbank);
 126
 127         if (enable)
 128                 val = mask;
 129         else
 130                 val = 0;
 131
 132         ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
 133                                                                         mask);
 134         if (ret)
 135                 return ret;
 136
 137         return len;
 138 }
 139
 140 static ssize_t show_linear(struct device *dev,
 141                                 struct device_attribute *attr, char *buf)
 142 {
 143         struct lm3533_bl *bl = dev_get_drvdata(dev);
 144         u8 val;
 145         u8 mask;
 146         int linear;
 147         int ret;
 148
 149         ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
 150         if (ret)
 151                 return ret;
 152
 153         mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
 154
 155         if (val & mask)
 156                 linear = 1;
 157         else
 158                 linear = 0;
 159
 160         return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
 161 }
 162
 163 static ssize_t store_linear(struct device *dev,
 164                                         struct device_attribute *attr,
 165                                         const char *buf, size_t len)
 166 {
 167         struct lm3533_bl *bl = dev_get_drvdata(dev);
 168         unsigned long linear;
 169         u8 mask;
 170         u8 val;
 171         int ret;
 172
 173         if (kstrtoul(buf, 0, &linear))
 174                 return -EINVAL;
 175
 176         mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
 177
 178         if (linear)
 179                 val = mask;
 180         else
 181                 val = 0;
 182
 183         ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
 184                                                                         mask);
 185         if (ret)
 186                 return ret;
 187
 188         return len;
 189 }
 190
 191 static ssize_t show_pwm(struct device *dev,
 192                                         struct device_attribute *attr,
 193                                         char *buf)
 194 {
 195         struct lm3533_bl *bl = dev_get_drvdata(dev);
 196         u8 val;
 197         int ret;
 198
 199         ret = lm3533_ctrlbank_get_pwm(&bl->cb, &val);
 200         if (ret)
 201                 return ret;
 202
 203         return scnprintf(buf, PAGE_SIZE, "%u\n", val);
 204 }
 205
 206 static ssize_t store_pwm(struct device *dev,
 207                                         struct device_attribute *attr,
 208                                         const char *buf, size_t len)
 209 {
 210         struct lm3533_bl *bl = dev_get_drvdata(dev);
 211         u8 val;
 212         int ret;
 213
 214         if (kstrtou8(buf, 0, &val))
 215                 return -EINVAL;
 216
 217         ret = lm3533_ctrlbank_set_pwm(&bl->cb, val);
 218         if (ret)
 219                 return ret;
 220
 221         return len;
 222 }
 223
 224 static LM3533_ATTR_RO(als_channel);
 225 static LM3533_ATTR_RW(als_en);
 226 static LM3533_ATTR_RO(id);
 227 static LM3533_ATTR_RW(linear);
 228 static LM3533_ATTR_RW(pwm);
 229
 230 static struct attribute *lm3533_bl_attributes[] = {
 231         &dev_attr_als_channel.attr,
 232         &dev_attr_als_en.attr,
 233         &dev_attr_id.attr,
 234         &dev_attr_linear.attr,
 235         &dev_attr_pwm.attr,
 236         NULL,
 237 };
 238
 239 static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
 240                                              struct attribute *attr, int n)
 241 {
 242         struct device *dev = container_of(kobj, struct device, kobj);
 243         struct lm3533_bl *bl = dev_get_drvdata(dev);
 244         umode_t mode = attr->mode;
 245
 246         if (attr == &dev_attr_als_channel.attr ||
 247                                         attr == &dev_attr_als_en.attr) {
 248                 if (!bl->lm3533->have_als)
 249                         mode = 0;
 250         }
 251
 252         return mode;
 253 };
 254
 255 static struct attribute_group lm3533_bl_attribute_group = {
 256         .is_visible     = lm3533_bl_attr_is_visible,
 257         .attrs          = lm3533_bl_attributes
 258 };
 259
 260 static int lm3533_bl_setup(struct lm3533_bl *bl,
 261                                         struct lm3533_bl_platform_data *pdata)
 262 {
 263         int ret;
 264
 265         ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
 266         if (ret)
 267                 return ret;
 268
 269         return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
 270 }
 271
 272 static int lm3533_bl_probe(struct platform_device *pdev)
 273 {
 274         struct lm3533 *lm3533;
 275         struct lm3533_bl_platform_data *pdata;
 276         struct lm3533_bl *bl;
 277         struct backlight_device *bd;
 278         struct backlight_properties props;
 279         int ret;
 280
 281         dev_dbg(&pdev->dev, "%s\n", __func__);
 282
 283         lm3533 = dev_get_drvdata(pdev->dev.parent);
 284         if (!lm3533)
 285                 return -EINVAL;
 286
 287         pdata = dev_get_platdata(&pdev->dev);
 288         if (!pdata) {
 289                 dev_err(&pdev->dev, "no platform data\n");
 290                 return -EINVAL;
 291         }
 292
 293         if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
 294                 dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
 295                 return -EINVAL;
 296         }
 297
 298         bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
 299         if (!bl)
 300                 return -ENOMEM;
 301
 302         bl->lm3533 = lm3533;
 303         bl->id = pdev->id;
 304
 305         bl->cb.lm3533 = lm3533;
 306         bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
 307         bl->cb.dev = NULL;                      /* until registered */
 308
 309         memset(&props, 0, sizeof(props));
 310         props.type = BACKLIGHT_RAW;
 311         props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
 312         props.brightness = pdata->default_brightness;
 313         bd = devm_backlight_device_register(&pdev->dev, pdata->name,
 314                                         pdev->dev.parent, bl, &lm3533_bl_ops,
 315                                         &props);
 316         if (IS_ERR(bd)) {
 317                 dev_err(&pdev->dev, "failed to register backlight device\n");
 318                 return PTR_ERR(bd);
 319         }
 320
 321         bl->bd = bd;
 322         bl->cb.dev = &bl->bd->dev;
 323
 324         platform_set_drvdata(pdev, bl);
 325
 326         ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 327         if (ret < 0) {
 328                 dev_err(&pdev->dev, "failed to create sysfs attributes\n");
 329                 return ret;
 330         }
 331
 332         backlight_update_status(bd);
 333
 334         ret = lm3533_bl_setup(bl, pdata);
 335         if (ret)
 336                 goto err_sysfs_remove;
 337
 338         ret = lm3533_ctrlbank_enable(&bl->cb);
 339         if (ret)
 340                 goto err_sysfs_remove;
 341
 342         return 0;
 343
 344 err_sysfs_remove:
 345         sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 346
 347         return ret;
 348 }
 349
 350 static int lm3533_bl_remove(struct platform_device *pdev)
 351 {
 352         struct lm3533_bl *bl = platform_get_drvdata(pdev);
 353         struct backlight_device *bd = bl->bd;
 354
 355         dev_dbg(&bd->dev, "%s\n", __func__);
 356
 357         bd->props.power = FB_BLANK_POWERDOWN;
 358         bd->props.brightness = 0;
 359
 360         lm3533_ctrlbank_disable(&bl->cb);
 361         sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 362
 363         return 0;
 364 }
 365
 366 #ifdef CONFIG_PM_SLEEP
 367 static int lm3533_bl_suspend(struct device *dev)
 368 {
 369         struct lm3533_bl *bl = dev_get_drvdata(dev);
 370
 371         dev_dbg(dev, "%s\n", __func__);
 372
 373         return lm3533_ctrlbank_disable(&bl->cb);
 374 }
 375
 376 static int lm3533_bl_resume(struct device *dev)
 377 {
 378         struct lm3533_bl *bl = dev_get_drvdata(dev);
 379
 380         dev_dbg(dev, "%s\n", __func__);
 381
 382         return lm3533_ctrlbank_enable(&bl->cb);
 383 }
 384 #endif
 385
 386 static SIMPLE_DEV_PM_OPS(lm3533_bl_pm_ops, lm3533_bl_suspend, lm3533_bl_resume);
 387
 388 static void lm3533_bl_shutdown(struct platform_device *pdev)
 389 {
 390         struct lm3533_bl *bl = platform_get_drvdata(pdev);
 391
 392         dev_dbg(&pdev->dev, "%s\n", __func__);
 393
 394         lm3533_ctrlbank_disable(&bl->cb);
 395 }
 396
 397 static struct platform_driver lm3533_bl_driver = {
 398         .driver = {
 399                 .name   = "lm3533-backlight",
 400                 .pm     = &lm3533_bl_pm_ops,
 401         },
 402         .probe          = lm3533_bl_probe,
 403         .remove         = lm3533_bl_remove,
 404         .shutdown       = lm3533_bl_shutdown,
 405 };
 406 module_platform_driver(lm3533_bl_driver);
 407
 408 MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
 409 MODULE_DESCRIPTION("LM3533 Backlight driver");
 410 MODULE_LICENSE("GPL");
 411 MODULE_ALIAS("platform:lm3533-backlight");