drm/i915: Add HAS_DISPLAY() and use it

Right now it is decided if GEN has display by checking the num_pipes,
so lets make it explicit and use a macro.

Cc: Jani Nikula <[e-mail]>
Reviewed-by: Lucas De Marchi <[e-mail]>
Signed-off-by: José Roberto de Souza <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/i915_drv.c

···
 	 * Use PCH_NOP (PCH but no South Display) for PCH platforms without
 	 * display.
 	 */
-	if (pch && INTEL_INFO(dev_priv)->num_pipes == 0) {
+	if (pch && !HAS_DISPLAY(dev_priv)) {
 		DRM_DEBUG_KMS("Display disabled, reverting to NOP PCH\n");
 		dev_priv->pch_type = PCH_NOP;
 		dev_priv->pch_id = 0;
···
 	if (i915_inject_load_failure())
 		return -ENODEV;
 
-	if (INTEL_INFO(dev_priv)->num_pipes) {
+	if (HAS_DISPLAY(dev_priv)) {
 		ret = drm_vblank_init(&dev_priv->drm,
 				      INTEL_INFO(dev_priv)->num_pipes);
 		if (ret)
···
 
 	intel_overlay_setup(dev_priv);
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0)
+	if (!HAS_DISPLAY(dev_priv))
 		return 0;
 
 	ret = intel_fbdev_init(dev);
···
 	} else
 		DRM_ERROR("Failed to register driver for userspace access!\n");
 
-	if (INTEL_INFO(dev_priv)->num_pipes) {
+	if (HAS_DISPLAY(dev_priv)) {
 		/* Must be done after probing outputs */
 		intel_opregion_register(dev_priv);
 		acpi_video_register();
···
 	 * We need to coordinate the hotplugs with the asynchronous fbdev
 	 * configuration, for which we use the fbdev->async_cookie.
 	 */
-	if (INTEL_INFO(dev_priv)->num_pipes)
+	if (HAS_DISPLAY(dev_priv))
 		drm_kms_helper_poll_init(dev);
 
 	intel_power_domains_enable(dev_priv);

drivers/gpu/drm/i915/i915_drv.h

···
 #define GT_FREQUENCY_MULTIPLIER 50
 #define GEN9_FREQ_SCALER 3
 
+#define HAS_DISPLAY(dev_priv) (INTEL_INFO(dev_priv)->num_pipes > 0)
+
 #include "i915_trace.h"
 
 static inline bool intel_vtd_active(void)

drivers/gpu/drm/i915/intel_bios.c

···
 	const struct bdb_header *bdb;
 	u8 __iomem *bios = NULL;
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0) {
+	if (!HAS_DISPLAY(dev_priv)) {
 		DRM_DEBUG_KMS("Skipping VBT init due to disabled display.\n");
 		return;
 	}

drivers/gpu/drm/i915/intel_device_info.c

···
 	if (i915_modparams.disable_display) {
 		DRM_INFO("Display disabled (module parameter)\n");
 		info->num_pipes = 0;
-	} else if (info->num_pipes > 0 &&
+	} else if (HAS_DISPLAY(dev_priv) &&
 		   (IS_GEN7(dev_priv) || IS_GEN8(dev_priv)) &&
 		   HAS_PCH_SPLIT(dev_priv)) {
 		u32 fuse_strap = I915_READ(FUSE_STRAP);
···
 			DRM_INFO("PipeC fused off\n");
 			info->num_pipes -= 1;
 		}
-	} else if (info->num_pipes > 0 && IS_GEN9(dev_priv)) {
+	} else if (HAS_DISPLAY(dev_priv) && IS_GEN9(dev_priv)) {
 		u32 dfsm = I915_READ(SKL_DFSM);
 		u8 disabled_mask = 0;
 		bool invalid;

drivers/gpu/drm/i915/intel_display.c

···
 
 	intel_pps_init(dev_priv);
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0)
+	if (!HAS_DISPLAY(dev_priv))
 		return;
 
 	/*
···
 	};
 	int i;
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0)
+	if (!HAS_DISPLAY(dev_priv))
 		return NULL;
 
 	error = kzalloc(sizeof(*error), GFP_ATOMIC);

drivers/gpu/drm/i915/intel_fbdev.c

···
 	struct intel_fbdev *ifbdev;
 	int ret;
 
-	if (WARN_ON(INTEL_INFO(dev_priv)->num_pipes == 0))
+	if (WARN_ON(!HAS_DISPLAY(dev_priv)))
 		return -ENODEV;
 
 	ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);

drivers/gpu/drm/i915/intel_i2c.c

···
 	unsigned int pin;
 	int ret;
 
-	if (INTEL_INFO(dev_priv)->num_pipes == 0)
+	if (!HAS_DISPLAY(dev_priv))
 		return 0;
 
 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))