SYST_CON_REG
writel(SYST_CON_EN | SYST_CON_IRQ_EN, SYST_CON_REG(to));
writel(0, SYST_CON_REG(to_timer_of(clkevt)));
writel(SYST_CON_EN, SYST_CON_REG(to));
writel(SYST_CON_IRQ_CLR | SYST_CON_EN, SYST_CON_REG(to));
writel(SYST_CON_EN, SYST_CON_REG(to));