VIDOSD_C
writel(alpha, ctx->regs + VIDOSD_C(win));
writel(val, ctx->regs + VIDOSD_C(win));
offset = VIDOSD_C(win);
writel(0, regs + VIDOSD_C(win, sfb->variant));
writel(alpha, sfb->regs + VIDOSD_C(win->index, sfb->variant));