drivers/video/fbdev/core/fbsysfs.c

Source file repositories/reference/linux-study-clean/drivers/video/fbdev/core/fbsysfs.c

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/core/fbsysfs.c
Extension
.c
Size
11863 bytes
Lines
477
Domain
Driver Families
Bucket
drivers/video
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (strncmp(mstr, buf, max(count, i)) == 0) {

			var = fb_info->var;
			fb_videomode_to_var(&var, mode);
			if ((err = activate(fb_info, &var)))
				return err;
			fb_info->mode = mode;
			return count;
		}
	}
	return -EINVAL;
}

static ssize_t show_mode(struct device *device, struct device_attribute *attr,
			 char *buf)
{
	struct fb_info *fb_info = dev_get_drvdata(device);

	if (!fb_info->mode)
		return 0;

	return mode_string(buf, 0, fb_info->mode);
}

static ssize_t store_modes(struct device *device,
			   struct device_attribute *attr,
			   const char *buf, size_t count)
{
	struct fb_info *fb_info = dev_get_drvdata(device);
	LIST_HEAD(old_list);
	int i = count / sizeof(struct fb_videomode);

	if (i * sizeof(struct fb_videomode) != count)
		return -EINVAL;

	console_lock();
	lock_fb_info(fb_info);

	list_splice(&fb_info->modelist, &old_list);
	fb_videomode_to_modelist((const struct fb_videomode *)buf, i,
				 &fb_info->modelist);
	if (fb_new_modelist(fb_info)) {
		fb_destroy_modelist(&fb_info->modelist);
		list_splice(&old_list, &fb_info->modelist);
	} else
		fb_destroy_modelist(&old_list);

	unlock_fb_info(fb_info);
	console_unlock();

	return 0;
}

static ssize_t show_modes(struct device *device, struct device_attribute *attr,
			  char *buf)
{
	struct fb_info *fb_info = dev_get_drvdata(device);
	unsigned int i;
	struct fb_modelist *modelist;
	const struct fb_videomode *mode;

	i = 0;
	list_for_each_entry(modelist, &fb_info->modelist, list) {
		mode = &modelist->mode;
		i += mode_string(buf, i, mode);
	}
	return i;
}

static ssize_t store_bpp(struct device *device, struct device_attribute *attr,
			 const char *buf, size_t count)
{
	struct fb_info *fb_info = dev_get_drvdata(device);
	struct fb_var_screeninfo var;
	char ** last = NULL;
	int err;

	var = fb_info->var;
	var.bits_per_pixel = simple_strtoul(buf, last, 0);
	if ((err = activate(fb_info, &var)))
		return err;
	return count;
}

static ssize_t show_bpp(struct device *device, struct device_attribute *attr,
			char *buf)
{
	struct fb_info *fb_info = dev_get_drvdata(device);
	return sysfs_emit(buf, "%d\n", fb_info->var.bits_per_pixel);
}

Annotation

Implementation Notes