From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Date: Fri, 15 Sep 2017 17:42:06 +0100
Subject: drm: rcar-du: Implement system suspend/resume support
Git-commit: 7912dee7775e4c7590c227b4163bdb635bc50dd6
Patch-mainline: v4.16-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

To support system suspend operations we must ensure the hardware is
stopped, and resumed explicitly from the suspend and resume handlers.

Implement suspend and resume functions using the DRM atomic helper
functions.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/rcar-du/rcar_du_drv.c |   18 +++++++++++++++---
 drivers/gpu/drm/rcar-du/rcar_du_drv.h |    1 +
 2 files changed, 16 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -22,6 +22,7 @@
 #include <linux/wait.h>
 
 #include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
@@ -309,9 +310,19 @@ static struct drm_driver rcar_du_driver
 static int rcar_du_pm_suspend(struct device *dev)
 {
 	struct rcar_du_device *rcdu = dev_get_drvdata(dev);
+	struct drm_atomic_state *state;
 
 	drm_kms_helper_poll_disable(rcdu->ddev);
-	/* TODO Suspend the CRTC */
+	drm_fbdev_cma_set_suspend_unlocked(rcdu->fbdev, true);
+
+	state = drm_atomic_helper_suspend(rcdu->ddev);
+	if (IS_ERR(state)) {
+		drm_fbdev_cma_set_suspend_unlocked(rcdu->fbdev, false);
+		drm_kms_helper_poll_enable(rcdu->ddev);
+		return PTR_ERR(state);
+	}
+
+	rcdu->suspend_state = state;
 
 	return 0;
 }
@@ -320,9 +331,10 @@ static int rcar_du_pm_resume(struct devi
 {
 	struct rcar_du_device *rcdu = dev_get_drvdata(dev);
 
-	/* TODO Resume the CRTC */
-
+	drm_atomic_helper_resume(rcdu->ddev, rcdu->suspend_state);
+	drm_fbdev_cma_set_suspend_unlocked(rcdu->fbdev, false);
 	drm_kms_helper_poll_enable(rcdu->ddev);
+
 	return 0;
 }
 #endif
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
@@ -81,6 +81,7 @@ struct rcar_du_device {
 
 	struct drm_device *ddev;
 	struct drm_fbdev_cma *fbdev;
+	struct drm_atomic_state *suspend_state;
 
 	struct rcar_du_crtc crtcs[RCAR_DU_MAX_CRTCS];
 	unsigned int num_crtcs;