drm/bridge: analogix_dp: Add analogix_dp_psr_supported

So users know whether PSR should be enabled or not.

Cc: Yakir Yang <ykk@rock-chips.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474639600-30090-1-git-send-email-tomeu.vizoso@collabora.com

drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

@@ -98,6 +98,14 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
 	return 0;
 }
 
+int analogix_dp_psr_supported(struct device *dev)
+{
+	struct analogix_dp_device *dp = dev_get_drvdata(dev);
+
+	return dp->psr_support;
+}
+EXPORT_SYMBOL_GPL(analogix_dp_psr_supported);
+
 int analogix_dp_enable_psr(struct device *dev)
 {
 	struct analogix_dp_device *dp = dev_get_drvdata(dev);

include/drm/bridge/analogix_dp.h

@@ -38,6 +38,7 @@ struct analogix_dp_plat_data {
 			 struct drm_connector *);
 };
 
+int analogix_dp_psr_supported(struct device *dev);
 int analogix_dp_enable_psr(struct device *dev);
 int analogix_dp_disable_psr(struct device *dev);