IPS_CTL
crtc_state->ips_enabled = intel_de_read(display, IPS_CTL) & IPS_ENABLE;
if (intel_de_read(display, IPS_CTL) & IPS_ENABLE)
intel_de_write(display, IPS_CTL, val);
if (intel_de_wait_for_set(display, IPS_CTL, IPS_ENABLE, 50))
if (intel_de_wait_for_clear(display, IPS_CTL, IPS_ENABLE, 100))
intel_de_write(display, IPS_CTL, 0);
intel_de_posting_read(display, IPS_CTL);
MMIO_D(IPS_CTL);