drivers/video/vgastate.c

Source file repositories/reference/linux-study-clean/drivers/video/vgastate.c

File Facts

System
Linux kernel
Corpus path
drivers/video/vgastate.c
Extension
.c
Size
13566 bytes
Lines
491
Domain
Driver Families
Bucket
drivers/video
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 regstate {
	__u8 *vga_font0;
	__u8 *vga_font1;
	__u8 *vga_text;
	__u8 *vga_cmap;
	__u8 *attr;
	__u8 *crtc;
	__u8 *gfx;
	__u8 *seq;
	__u8 misc;
};

static inline unsigned char vga_rcrtcs(void __iomem *regbase, unsigned short iobase,
				       unsigned char reg)
{
	vga_w(regbase, iobase + 0x4, reg);
	return vga_r(regbase, iobase + 0x5);
}

static inline void vga_wcrtcs(void __iomem *regbase, unsigned short iobase,
			      unsigned char reg, unsigned char val)
{
	vga_w(regbase, iobase + 0x4, reg);
	vga_w(regbase, iobase + 0x5, val);
}

static void save_vga_text(struct vgastate *state, void __iomem *fbbase)
{
	struct regstate *saved = (struct regstate *) state->vidstate;
	int i;
	u8 misc, attr10, gr4, gr5, gr6, seq1, seq2, seq4;
	unsigned short iobase;

	/* if in graphics mode, no need to save */
	misc = vga_r(state->vgabase, VGA_MIS_R);
	iobase = (misc & 1) ? 0x3d0 : 0x3b0;

	vga_r(state->vgabase, iobase + 0xa);
	vga_w(state->vgabase, VGA_ATT_W, 0x00);
	attr10 = vga_rattr(state->vgabase, 0x10);
	vga_r(state->vgabase, iobase + 0xa);
	vga_w(state->vgabase, VGA_ATT_W, 0x20);

	if (attr10 & 1)
		return;

	/* save regs */
	gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
	gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
	gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
	seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
	seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);

	/* blank screen */
	seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 | 1 << 5);
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);

	/* save font at plane 2 */
	if (state->flags & VGA_SAVE_FONT0) {
		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x4);
		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x2);
		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
		for (i = 0; i < 4 * 8192; i++)
			saved->vga_font0[i] = vga_r(fbbase, i);
	}

	/* save font at plane 3 */
	if (state->flags & VGA_SAVE_FONT1) {
		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x8);
		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x3);
		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
		for (i = 0; i < state->memsize; i++)
			saved->vga_font1[i] = vga_r(fbbase, i);
	}

	/* save font at plane 0/1 */
	if (state->flags & VGA_SAVE_TEXT) {
		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x1);
		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x0);
		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
		for (i = 0; i < 8192; i++)
			saved->vga_text[i] = vga_r(fbbase, i);

Annotation

Implementation Notes