drm/exynos: Fix suspend/resume support

Commit 7d902c0 ("drm: Nuke drm_atomic_helper_connector_dpms")
removed drm_atomic_helper_connector_dpms() helper saying that it was a dead
code. It was however indirectly used by Exynos DRM driver for implementing
suspend/resume support. To fix this regression (after that patch Exynos DRM
suspend/resume functions became no-ops and hardware fails to suspend),
this patch rewrites them with drm_atomic_helper_suspend/resume() helpers.

Fixes: 7d902c0 ("drm: Nuke drm_atomic_helper_connector_dpms")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -168,50 +168,34 @@ static struct drm_driver exynos_drm_driver = {
 static int exynos_drm_suspend(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
-	struct drm_connector *connector;
-	struct drm_connector_list_iter conn_iter;
+	struct exynos_drm_private *private = drm_dev->dev_private;
 
 	if (pm_runtime_suspended(dev) || !drm_dev)
 		return 0;
 
-	drm_modeset_lock_all(drm_dev);
-	drm_connector_list_iter_begin(drm_dev, &conn_iter);
-	drm_for_each_connector_iter(connector, &conn_iter) {
-		int old_dpms = connector->dpms;
-
-		if (connector->funcs->dpms)
-			connector->funcs->dpms(connector, DRM_MODE_DPMS_OFF);
-
-		/* Set the old mode back to the connector for resume */
-		connector->dpms = old_dpms;
+	drm_kms_helper_poll_disable(drm_dev);
+	exynos_drm_fbdev_suspend(drm_dev);
+	private->suspend_state = drm_atomic_helper_suspend(drm_dev);
+	if (IS_ERR(private->suspend_state)) {
+		exynos_drm_fbdev_resume(drm_dev);
+		drm_kms_helper_poll_enable(drm_dev);
+		return PTR_ERR(private->suspend_state);
 	}
-	drm_connector_list_iter_end(&conn_iter);
-	drm_modeset_unlock_all(drm_dev);
 
 	return 0;
 }
 
 static int exynos_drm_resume(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
-	struct drm_connector *connector;
-	struct drm_connector_list_iter conn_iter;
+	struct exynos_drm_private *private = drm_dev->dev_private;
 
 	if (pm_runtime_suspended(dev) || !drm_dev)
 		return 0;
 
-	drm_modeset_lock_all(drm_dev);
-	drm_connector_list_iter_begin(drm_dev, &conn_iter);
-	drm_for_each_connector_iter(connector, &conn_iter) {
-		if (connector->funcs->dpms) {
-			int dpms = connector->dpms;
-
-			connector->dpms = DRM_MODE_DPMS_OFF;
-			connector->funcs->dpms(connector, dpms);
-		}
-	}
-	drm_connector_list_iter_end(&conn_iter);
-	drm_modeset_unlock_all(drm_dev);
+	drm_atomic_helper_resume(drm_dev, private->suspend_state);
+	exynos_drm_fbdev_resume(drm_dev);
+	drm_kms_helper_poll_enable(drm_dev);
 
 	return 0;
 }

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -202,6 +202,7 @@ struct drm_exynos_file_private {
  */
 struct exynos_drm_private {
 	struct drm_fb_helper *fb_helper;
+	struct drm_atomic_state *suspend_state;
 
 	struct device *dma_dev;
 	void *mapping;

drivers/gpu/drm/exynos/exynos_drm_fbdev.c

@@ -18,6 +18,8 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/exynos_drm.h>
 
+#include <linux/console.h>
+
 #include "exynos_drm_drv.h"
 #include "exynos_drm_fb.h"
 #include "exynos_drm_fbdev.h"
@@ -285,3 +287,21 @@ void exynos_drm_output_poll_changed(struct drm_device *dev)
 
 	drm_fb_helper_hotplug_event(fb_helper);
 }
+
+void exynos_drm_fbdev_suspend(struct drm_device *dev)
+{
+	struct exynos_drm_private *private = dev->dev_private;
+
+	console_lock();
+	drm_fb_helper_set_suspend(private->fb_helper, 1);
+	console_unlock();
+}
+
+void exynos_drm_fbdev_resume(struct drm_device *dev)
+{
+	struct exynos_drm_private *private = dev->dev_private;
+
+	console_lock();
+	drm_fb_helper_set_suspend(private->fb_helper, 0);
+	console_unlock();
+}

drivers/gpu/drm/exynos/exynos_drm_fbdev.h

@@ -21,6 +21,8 @@ int exynos_drm_fbdev_init(struct drm_device *dev);
 void exynos_drm_fbdev_fini(struct drm_device *dev);
 void exynos_drm_fbdev_restore_mode(struct drm_device *dev);
 void exynos_drm_output_poll_changed(struct drm_device *dev);
+void exynos_drm_fbdev_suspend(struct drm_device *drm);
+void exynos_drm_fbdev_resume(struct drm_device *drm);
 
 #else
 
@@ -39,6 +41,14 @@ static inline void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
 
 #define exynos_drm_output_poll_changed (NULL)
 
+static inline void exynos_drm_fbdev_suspend(struct drm_device *drm)
+{
+}
+
+static inline void exynos_drm_fbdev_resume(struct drm_device *drm)
+{
+}
+
 #endif
 
 #endif