| 1 | |
| 2 |
|
| 3 | #include <linux/backlight.h>
|
| 4 | #include <linux/export.h>
|
| 5 | #include <linux/fb.h>
|
| 6 | #include <linux/mutex.h>
|
| 7 |
|
| 8 | #if IS_ENABLED(CONFIG_FB_BACKLIGHT)
|
| 9 | |
| 10 | * This function generates a linear backlight curve
|
| 11 | *
|
| 12 | * 0: off
|
| 13 | * 1-7: min
|
| 14 | * 8-127: linear from min to max
|
| 15 |
|
| 16 | void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
|
| 17 | {
|
| 18 | unsigned int i, flat, count, range = (max - min);
|
| 19 |
|
| 20 | mutex_lock(&fb_info->bl_curve_mutex);
|
| 21 |
|
| 22 | fb_info->bl_curve[0] = off;
|
| 23 |
|
| 24 | for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
|
| 25 | fb_info->bl_curve[flat] = min;
|
| 26 |
|
| 27 | count = FB_BACKLIGHT_LEVELS * 15 / 16;
|
| 28 | for (i = 0; i < count; ++i)
|
| 29 | fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count);
|
| 30 |
|
| 31 | mutex_unlock(&fb_info->bl_curve_mutex);
|
| 32 | }
|
| 33 | EXPORT_SYMBOL_GPL(fb_bl_default_curve);
|
| 34 |
|
| 35 | struct backlight_device *fb_bl_device(struct fb_info *info)
|
| 36 | {
|
| 37 | return info->bl_dev;
|
| 38 | }
|
| 39 | EXPORT_SYMBOL(fb_bl_device);
|
| 40 |
|
| 41 | void fb_bl_notify_blank(struct fb_info *info, int old_blank)
|
| 42 | {
|
| 43 | bool on = info->blank == FB_BLANK_UNBLANK;
|
| 44 | bool prev_on = old_blank == FB_BLANK_UNBLANK;
|
| 45 |
|
| 46 | if (info->bl_dev)
|
| 47 | backlight_notify_blank(info->bl_dev, info->device, on, prev_on);
|
| 48 | else
|
| 49 | backlight_notify_blank_all(info->device, on, prev_on);
|
| 50 | }
|
| 51 | #endif
|