drm/imx: Convert drm_atomic_helper_suspend/resume()

convert drm_atomic_helper_suspend/resume() to use
drm_mode_config_helper_suspend/resume().

with this conversion, the remaining member of struct
imx_drm_device, state, will be no more useful and it
could be removed forever.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Ajit Negi <ajitn.linux@gmail.com>
[p.zabel@pengutronix.de: rebased onto drm-next, updated commit message]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/imx/imx-drm-core.c

@@ -35,11 +35,6 @@
 
 #define MAX_CRTC	4
 
-struct imx_drm_device {
-	struct drm_device			*drm;
-	struct drm_atomic_state			*state;
-};
-
 #if IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION)
 static int legacyfb_depth = 16;
 module_param(legacyfb_depth, int, 0444);
@@ -218,22 +213,12 @@ static int compare_of(struct device *dev, void *data)
 static int imx_drm_bind(struct device *dev)
 {
 	struct drm_device *drm;
-	struct imx_drm_device *imxdrm;
 	int ret;
 
 	drm = drm_dev_alloc(&imx_drm_driver, dev);
 	if (IS_ERR(drm))
 		return PTR_ERR(drm);
 
-	imxdrm = devm_kzalloc(dev, sizeof(*imxdrm), GFP_KERNEL);
-	if (!imxdrm) {
-		ret = -ENOMEM;
-		goto err_put;
-	}
-
-	imxdrm->drm = drm;
-	drm->dev_private = imxdrm;
-
 	/*
 	 * enable drm irq mode.
 	 * - with irq_enabled = true, we can use the vblank feature.
@@ -305,7 +290,6 @@ static int imx_drm_bind(struct device *dev)
 	component_unbind_all(drm->dev, drm);
 err_kms:
 	drm_mode_config_cleanup(drm);
-err_put:
 	drm_dev_put(drm);
 
 	return ret;
@@ -354,37 +338,15 @@ static int imx_drm_platform_remove(struct platform_device *pdev)
 static int imx_drm_suspend(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
-	struct imx_drm_device *imxdrm;
-
-	/* The drm_dev is NULL before .load hook is called */
-	if (drm_dev == NULL)
-		return 0;
-
-	drm_kms_helper_poll_disable(drm_dev);
 
-	imxdrm = drm_dev->dev_private;
-	imxdrm->state = drm_atomic_helper_suspend(drm_dev);
-	if (IS_ERR(imxdrm->state)) {
-		drm_kms_helper_poll_enable(drm_dev);
-		return PTR_ERR(imxdrm->state);
-	}
-
-	return 0;
+	return drm_mode_config_helper_suspend(drm_dev);
 }
 
 static int imx_drm_resume(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
-	struct imx_drm_device *imx_drm;
 
-	if (drm_dev == NULL)
-		return 0;
-
-	imx_drm = drm_dev->dev_private;
-	drm_atomic_helper_resume(drm_dev, imx_drm->state);
-	drm_kms_helper_poll_enable(drm_dev);
-
-	return 0;
+	return drm_mode_config_helper_resume(drm_dev);
 }
 #endif