drivers/video/backlight/lm3533_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * lm3533-bl.c -- LM3533 Backlight driver
   4  *
   5  * Copyright (C) 2011-2012 Texas Instruments
   6  *
   7  * Author: Johan Hovold <jhovold@gmail.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/backlight.h>
  14 #include <linux/slab.h>
  15
  16 #include <linux/mfd/lm3533.h>
  17
  18
  19 #define LM3533_HVCTRLBANK_COUNT         2
  20 #define LM3533_BL_MAX_BRIGHTNESS        255
  21
  22 #define LM3533_REG_CTRLBANK_AB_BCONF    0x1a
  23
  24
  25 struct lm3533_bl {
  26         struct lm3533 *lm3533;
  27         struct lm3533_ctrlbank cb;
  28         struct backlight_device *bd;
  29         int id;
  30 };
  31
  32
  33 static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
  34 {
  35         return bl->id;
  36 }
  37
  38 static int lm3533_bl_update_status(struct backlight_device *bd)
  39 {
  40         struct lm3533_bl *bl = bl_get_data(bd);
  41
  42         return lm3533_ctrlbank_set_brightness(&bl->cb, backlight_get_brightness(bd));
  43 }
  44
  45 static int lm3533_bl_get_brightness(struct backlight_device *bd)
  46 {
  47         struct lm3533_bl *bl = bl_get_data(bd);
  48         u8 val;
  49         int ret;
  50
  51         ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
  52         if (ret)
  53                 return ret;
  54
  55         return val;
  56 }
  57
  58 static const struct backlight_ops lm3533_bl_ops = {
  59         .get_brightness = lm3533_bl_get_brightness,
  60         .update_status  = lm3533_bl_update_status,
  61 };
  62
  63 static ssize_t show_id(struct device *dev,
  64                                 struct device_attribute *attr, char *buf)
  65 {
  66         struct lm3533_bl *bl = dev_get_drvdata(dev);
  67
  68         return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
  69 }
  70
  71 static ssize_t show_als_channel(struct device *dev,
  72                                 struct device_attribute *attr, char *buf)
  73 {
  74         struct lm3533_bl *bl = dev_get_drvdata(dev);
  75         unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
  76
  77         return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
  78 }
  79
  80 static ssize_t show_als_en(struct device *dev,
  81                                 struct device_attribute *attr, char *buf)
  82 {
  83         struct lm3533_bl *bl = dev_get_drvdata(dev);
  84         int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
  85         u8 val;
  86         u8 mask;
  87         bool enable;
  88         int ret;
  89
  90         ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
  91         if (ret)
  92                 return ret;
  93
  94         mask = 1 << (2 * ctrlbank);
  95         enable = val & mask;
  96
  97         return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
  98 }
  99
 100 static ssize_t store_als_en(struct device *dev,
 101                                         struct device_attribute *attr,
 102                                         const char *buf, size_t len)
 103 {
 104         struct lm3533_bl *bl = dev_get_drvdata(dev);
 105         int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
 106         int enable;
 107         u8 val;
 108         u8 mask;
 109         int ret;
 110
 111         if (kstrtoint(buf, 0, &enable))
 112                 return -EINVAL;
 113
 114         mask = 1 << (2 * ctrlbank);
 115
 116         if (enable)
 117                 val = mask;
 118         else
 119                 val = 0;
 120
 121         ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
 122                                                                         mask);
 123         if (ret)
 124                 return ret;
 125
 126         return len;
 127 }
 128
 129 static ssize_t show_linear(struct device *dev,
 130                                 struct device_attribute *attr, char *buf)
 131 {
 132         struct lm3533_bl *bl = dev_get_drvdata(dev);
 133         u8 val;
 134         u8 mask;
 135         int linear;
 136         int ret;
 137
 138         ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
 139         if (ret)
 140                 return ret;
 141
 142         mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
 143
 144         if (val & mask)
 145                 linear = 1;
 146         else
 147                 linear = 0;
 148
 149         return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
 150 }
 151
 152 static ssize_t store_linear(struct device *dev,
 153                                         struct device_attribute *attr,
 154                                         const char *buf, size_t len)
 155 {
 156         struct lm3533_bl *bl = dev_get_drvdata(dev);
 157         unsigned long linear;
 158         u8 mask;
 159         u8 val;
 160         int ret;
 161
 162         if (kstrtoul(buf, 0, &linear))
 163                 return -EINVAL;
 164
 165         mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
 166
 167         if (linear)
 168                 val = mask;
 169         else
 170                 val = 0;
 171
 172         ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
 173                                                                         mask);
 174         if (ret)
 175                 return ret;
 176
 177         return len;
 178 }
 179
 180 static ssize_t show_pwm(struct device *dev,
 181                                         struct device_attribute *attr,
 182                                         char *buf)
 183 {
 184         struct lm3533_bl *bl = dev_get_drvdata(dev);
 185         u8 val;
 186         int ret;
 187
 188         ret = lm3533_ctrlbank_get_pwm(&bl->cb, &val);
 189         if (ret)
 190                 return ret;
 191
 192         return scnprintf(buf, PAGE_SIZE, "%u\n", val);
 193 }
 194
 195 static ssize_t store_pwm(struct device *dev,
 196                                         struct device_attribute *attr,
 197                                         const char *buf, size_t len)
 198 {
 199         struct lm3533_bl *bl = dev_get_drvdata(dev);
 200         u8 val;
 201         int ret;
 202
 203         if (kstrtou8(buf, 0, &val))
 204                 return -EINVAL;
 205
 206         ret = lm3533_ctrlbank_set_pwm(&bl->cb, val);
 207         if (ret)
 208                 return ret;
 209
 210         return len;
 211 }
 212
 213 static LM3533_ATTR_RO(als_channel);
 214 static LM3533_ATTR_RW(als_en);
 215 static LM3533_ATTR_RO(id);
 216 static LM3533_ATTR_RW(linear);
 217 static LM3533_ATTR_RW(pwm);
 218
 219 static struct attribute *lm3533_bl_attributes[] = {
 220         &dev_attr_als_channel.attr,
 221         &dev_attr_als_en.attr,
 222         &dev_attr_id.attr,
 223         &dev_attr_linear.attr,
 224         &dev_attr_pwm.attr,
 225         NULL,
 226 };
 227
 228 static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
 229                                              struct attribute *attr, int n)
 230 {
 231         struct device *dev = kobj_to_dev(kobj);
 232         struct lm3533_bl *bl = dev_get_drvdata(dev);
 233         umode_t mode = attr->mode;
 234
 235         if (attr == &dev_attr_als_channel.attr ||
 236                                         attr == &dev_attr_als_en.attr) {
 237                 if (!bl->lm3533->have_als)
 238                         mode = 0;
 239         }
 240
 241         return mode;
 242 };
 243
 244 static struct attribute_group lm3533_bl_attribute_group = {
 245         .is_visible     = lm3533_bl_attr_is_visible,
 246         .attrs          = lm3533_bl_attributes
 247 };
 248
 249 static int lm3533_bl_setup(struct lm3533_bl *bl,
 250                                         struct lm3533_bl_platform_data *pdata)
 251 {
 252         int ret;
 253
 254         ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
 255         if (ret)
 256                 return ret;
 257
 258         return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
 259 }
 260
 261 static int lm3533_bl_probe(struct platform_device *pdev)
 262 {
 263         struct lm3533 *lm3533;
 264         struct lm3533_bl_platform_data *pdata;
 265         struct lm3533_bl *bl;
 266         struct backlight_device *bd;
 267         struct backlight_properties props;
 268         int ret;
 269
 270         dev_dbg(&pdev->dev, "%s\n", __func__);
 271
 272         lm3533 = dev_get_drvdata(pdev->dev.parent);
 273         if (!lm3533)
 274                 return -EINVAL;
 275
 276         pdata = dev_get_platdata(&pdev->dev);
 277         if (!pdata) {
 278                 dev_err(&pdev->dev, "no platform data\n");
 279                 return -EINVAL;
 280         }
 281
 282         if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
 283                 dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
 284                 return -EINVAL;
 285         }
 286
 287         bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
 288         if (!bl)
 289                 return -ENOMEM;
 290
 291         bl->lm3533 = lm3533;
 292         bl->id = pdev->id;
 293
 294         bl->cb.lm3533 = lm3533;
 295         bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
 296         bl->cb.dev = NULL;                      /* until registered */
 297
 298         memset(&props, 0, sizeof(props));
 299         props.type = BACKLIGHT_RAW;
 300         props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
 301         props.brightness = pdata->default_brightness;
 302         bd = devm_backlight_device_register(&pdev->dev, pdata->name,
 303                                         pdev->dev.parent, bl, &lm3533_bl_ops,
 304                                         &props);
 305         if (IS_ERR(bd)) {
 306                 dev_err(&pdev->dev, "failed to register backlight device\n");
 307                 return PTR_ERR(bd);
 308         }
 309
 310         bl->bd = bd;
 311         bl->cb.dev = &bl->bd->dev;
 312
 313         platform_set_drvdata(pdev, bl);
 314
 315         ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 316         if (ret < 0) {
 317                 dev_err(&pdev->dev, "failed to create sysfs attributes\n");
 318                 return ret;
 319         }
 320
 321         backlight_update_status(bd);
 322
 323         ret = lm3533_bl_setup(bl, pdata);
 324         if (ret)
 325                 goto err_sysfs_remove;
 326
 327         ret = lm3533_ctrlbank_enable(&bl->cb);
 328         if (ret)
 329                 goto err_sysfs_remove;
 330
 331         return 0;
 332
 333 err_sysfs_remove:
 334         sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 335
 336         return ret;
 337 }
 338
 339 static void lm3533_bl_remove(struct platform_device *pdev)
 340 {
 341         struct lm3533_bl *bl = platform_get_drvdata(pdev);
 342         struct backlight_device *bd = bl->bd;
 343
 344         dev_dbg(&bd->dev, "%s\n", __func__);
 345
 346         bd->props.power = BACKLIGHT_POWER_OFF;
 347         bd->props.brightness = 0;
 348
 349         lm3533_ctrlbank_disable(&bl->cb);
 350         sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
 351 }
 352
 353 #ifdef CONFIG_PM_SLEEP
 354 static int lm3533_bl_suspend(struct device *dev)
 355 {
 356         struct lm3533_bl *bl = dev_get_drvdata(dev);
 357
 358         dev_dbg(dev, "%s\n", __func__);
 359
 360         return lm3533_ctrlbank_disable(&bl->cb);
 361 }
 362
 363 static int lm3533_bl_resume(struct device *dev)
 364 {
 365         struct lm3533_bl *bl = dev_get_drvdata(dev);
 366
 367         dev_dbg(dev, "%s\n", __func__);
 368
 369         return lm3533_ctrlbank_enable(&bl->cb);
 370 }
 371 #endif
 372
 373 static SIMPLE_DEV_PM_OPS(lm3533_bl_pm_ops, lm3533_bl_suspend, lm3533_bl_resume);
 374
 375 static void lm3533_bl_shutdown(struct platform_device *pdev)
 376 {
 377         struct lm3533_bl *bl = platform_get_drvdata(pdev);
 378
 379         dev_dbg(&pdev->dev, "%s\n", __func__);
 380
 381         lm3533_ctrlbank_disable(&bl->cb);
 382 }
 383
 384 static struct platform_driver lm3533_bl_driver = {
 385         .driver = {
 386                 .name   = "lm3533-backlight",
 387                 .pm     = &lm3533_bl_pm_ops,
 388         },
 389         .probe          = lm3533_bl_probe,
 390         .remove         = lm3533_bl_remove,
 391         .shutdown       = lm3533_bl_shutdown,
 392 };
 393 module_platform_driver(lm3533_bl_driver);
 394
 395 MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
 396 MODULE_DESCRIPTION("LM3533 Backlight driver");
 397 MODULE_LICENSE("GPL");
 398 MODULE_ALIAS("platform:lm3533-backlight");