BXT_DSI_PLL_CTL
val = I915_READ(BXT_DSI_PLL_CTL);
config->dsi_pll.ctrl = I915_READ(BXT_DSI_PLL_CTL);
I915_WRITE(BXT_DSI_PLL_CTL, config->dsi_pll.ctrl);
POSTING_READ(BXT_DSI_PLL_CTL);