SM501_DC_PANEL_CONTROL
ctrl = smc501_readl(info->regs + SM501_DC_PANEL_CONTROL);
void __iomem *ctrl_reg = fbi->regs + SM501_DC_PANEL_CONTROL;
control = smc501_readl(fbi->regs + SM501_DC_PANEL_CONTROL);
smc501_writel(control, fbi->regs + SM501_DC_PANEL_CONTROL);