BXT_BLC_PWM_FREQ
I915_WRITE(BXT_BLC_PWM_FREQ(panel->backlight.controller),
I915_WRITE(BXT_BLC_PWM_FREQ(panel->backlight.controller),
I915_READ(BXT_BLC_PWM_FREQ(panel->backlight.controller));
I915_READ(BXT_BLC_PWM_FREQ(panel->backlight.controller));