sun4i_pwm_readl
val = sun4i_pwm_readl(sun4ichip, PWM_CTRL_REG);
val = sun4i_pwm_readl(sun4ichip, PWM_CH_PRD(pwm->hwpwm));
ctrl = sun4i_pwm_readl(sun4ichip, PWM_CTRL_REG);
ctrl = sun4i_pwm_readl(sun4ichip, PWM_CTRL_REG);