drm/i915/dsi: skip gpio element execution when not supported

Skip v3 gpio element because the support is not there, and skip gpio
element on non-vlv because the sideband code is vlv specific.

v2: the gpio stuff is currently only supported on vlv (Ville)

Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 2a33d93486f2 ("drm/i915/bios: add support for MIPI sequence block v3")
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454604767-2440-1-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_dsi_panel_vbt.c

@@ -204,6 +204,9 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
 	struct drm_device *dev = intel_dsi->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	if (dev_priv->vbt.dsi.seq_version >= 3)
+		data++;
+
 	gpio = *data++;
 
 	/* pull up/down */
@@ -214,6 +217,16 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
 		goto out;
 	}
 
+	if (!IS_VALLEYVIEW(dev_priv)) {
+		DRM_DEBUG_KMS("GPIO element not supported on this platform\n");
+		goto out;
+	}
+
+	if (dev_priv->vbt.dsi.seq_version >= 3) {
+		DRM_DEBUG_KMS("GPIO element v3 not supported\n");
+		goto out;
+	}
+
 	function = gtable[gpio].function_reg;
 	pad = gtable[gpio].pad_reg;