PWMCR
writel(prescale | PWMCR_SD, pc->mmio_base + offset + PWMCR);
spear_pwm_writel(pc, pwm->hwpwm, PWMCR,
val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);
spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);
val = spear_pwm_readl(pc, pwm->hwpwm, PWMCR);
spear_pwm_writel(pc, pwm->hwpwm, PWMCR, val);