diff options
Diffstat (limited to 'drivers/video/fbsysfs.c')
| -rw-r--r-- | drivers/video/fbsysfs.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/video/fbsysfs.c b/drivers/video/fbsysfs.c index 34e07399756b..3ceb8c1b392e 100644 --- a/drivers/video/fbsysfs.c +++ b/drivers/video/fbsysfs.c @@ -18,6 +18,7 @@ #include <linux/kernel.h> #include <linux/fb.h> #include <linux/console.h> +#include <linux/module.h> /** * framebuffer_alloc - creates a new frame buffer info structure @@ -55,6 +56,10 @@ struct fb_info *framebuffer_alloc(size_t size, struct device *dev) info->device = dev; +#ifdef CONFIG_FB_BACKLIGHT + mutex_init(&info->bl_mutex); +#endif + return info; #undef PADDING #undef BYTES_PER_LONG @@ -414,6 +419,65 @@ static ssize_t show_fbstate(struct class_device *class_device, char *buf) return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->state); } +#ifdef CONFIG_FB_BACKLIGHT +static ssize_t store_bl_curve(struct class_device *class_device, + const char *buf, size_t count) +{ + struct fb_info *fb_info = class_get_devdata(class_device); + u8 tmp_curve[FB_BACKLIGHT_LEVELS]; + unsigned int i; + + if (count != (FB_BACKLIGHT_LEVELS / 8 * 24)) + return -EINVAL; + + for (i = 0; i < (FB_BACKLIGHT_LEVELS / 8); ++i) + if (sscanf(&buf[i * 24], + "%2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx\n", + &tmp_curve[i * 8 + 0], + &tmp_curve[i * 8 + 1], + &tmp_curve[i * 8 + 2], + &tmp_curve[i * 8 + 3], + &tmp_curve[i * 8 + 4], + &tmp_curve[i * 8 + 5], + &tmp_curve[i * 8 + 6], + &tmp_curve[i * 8 + 7]) != 8) + return -EINVAL; + + /* If there has been an error in the input data, we won't + * reach this loop. + */ + mutex_lock(&fb_info->bl_mutex); + for (i = 0; i < FB_BACKLIGHT_LEVELS; ++i) + fb_info->bl_curve[i] = tmp_curve[i]; + mutex_unlock(&fb_info->bl_mutex); + + return count; +} + +static ssize_t show_bl_curve(struct class_device *class_device, char *buf) +{ + struct fb_info *fb_info = class_get_devdata(class_device); + ssize_t len = 0; + unsigned int i; + + mutex_lock(&fb_info->bl_mutex); + for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8) + len += snprintf(&buf[len], PAGE_SIZE, + "%02x %02x %02x %02x %02x %02x %02x %02x\n", + fb_info->bl_curve[i + 0], + fb_info->bl_curve[i + 1], + fb_info->bl_curve[i + 2], + fb_info->bl_curve[i + 3], + fb_info->bl_curve[i + 4], + fb_info->bl_curve[i + 5], + fb_info->bl_curve[i + 6], + fb_info->bl_curve[i + 7]); + mutex_unlock(&fb_info->bl_mutex); + + return len; +} +#endif + /* When cmap is added back in it should be a binary attribute * not a text one. Consideration should also be given to converting * fbdev to use configfs instead of sysfs */ @@ -432,6 +496,9 @@ static struct class_device_attribute class_device_attrs[] = { __ATTR(con_rotate, S_IRUGO|S_IWUSR, show_con_rotate, store_con_rotate), __ATTR(con_rotate_all, S_IWUSR, NULL, store_con_rotate_all), __ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate), +#ifdef CONFIG_FB_BACKLIGHT + __ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve), +#endif }; int fb_init_class_device(struct fb_info *fb_info) @@ -454,4 +521,25 @@ void fb_cleanup_class_device(struct fb_info *fb_info) &class_device_attrs[i]); } +#ifdef CONFIG_FB_BACKLIGHT +/* This function generates a linear backlight curve + * + * 0: off + * 1-7: min + * 8-127: linear from min to max + */ +void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max) +{ + unsigned int i, flat, count, range = (max - min); + + fb_info->bl_curve[0] = off; + for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat) + fb_info->bl_curve[flat] = min; + + count = FB_BACKLIGHT_LEVELS * 15 / 16; + for (i = 0; i < count; ++i) + fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count); +} +EXPORT_SYMBOL_GPL(fb_bl_default_curve); +#endif |