drivers/video/fbdev/core/cfbmem.h

Source file repositories/reference/linux-study-clean/drivers/video/fbdev/core/cfbmem.h

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/core/cfbmem.h
Extension
.h
Size
1245 bytes
Lines
44
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

struct fb_address {
	void __iomem *address;
	int bits;
};

/* initialize the bit address pointer to the beginning of the frame buffer */
static inline struct fb_address fb_address_init(struct fb_info *p)
{
	void __iomem *base = p->screen_base;
	struct fb_address ptr;

	ptr.address = PTR_ALIGN_DOWN(base, BITS_PER_LONG / BITS_PER_BYTE);
	ptr.bits = (base - ptr.address) * BITS_PER_BYTE;
	return ptr;
}

/* framebuffer write access */
static inline void fb_write_offset(unsigned long val, int offset, const struct fb_address *dst)
{
#if BITS_PER_LONG == 32
	fb_writel(val, dst->address + offset * (BITS_PER_LONG / BITS_PER_BYTE));
#else
	fb_writeq(val, dst->address + offset * (BITS_PER_LONG / BITS_PER_BYTE));
#endif
}

/* framebuffer read access */
static inline unsigned long fb_read_offset(int offset, const struct fb_address *src)
{
#if BITS_PER_LONG == 32
	return fb_readl(src->address + offset * (BITS_PER_LONG / BITS_PER_BYTE));
#else
	return fb_readq(src->address + offset * (BITS_PER_LONG / BITS_PER_BYTE));
#endif
}

Annotation

Implementation Notes