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