Revert "drm/rockchip: vop2: Use regcache_sync() to fix suspend/resume"

This reverts commit b63a553e.

regcache_sync will try to reload the configuration in regcache to
hardware, but the registers of 4 Cluster windows and Esmart1/2/3 on
the upcoming rk3588 can not be set successfully before internal PD
power on.

Also it's better to keep the hardware register as it is before we really
enable it.

So let's revert this version, and keep the first version:
commit afa965a4 ("drm/rockchip: vop2: fix suspend/resume")
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231211115719.1784834-1-andyshrk@163.com

drivers/gpu/drm/rockchip/rockchip_drm_vop2.c

@@ -217,6 +217,8 @@ struct vop2 {
 	struct vop2_win win[];
 };
 
+static const struct regmap_config vop2_regmap_config;
+
 static struct vop2_video_port *to_vop2_video_port(struct drm_crtc *crtc)
 {
 	return container_of(crtc, struct vop2_video_port, crtc);
@@ -883,7 +885,11 @@ static void vop2_enable(struct vop2 *vop2)
 		return;
 	}
 
-	regcache_sync(vop2->map);
+	ret = regmap_reinit_cache(vop2->map, &vop2_regmap_config);
+	if (ret) {
+		drm_err(vop2->drm, "failed to reinit cache: %d\n", ret);
+		return;
+	}
 
 	if (vop2->data->soc_id == 3566)
 		vop2_writel(vop2, RK3568_OTP_WIN_EN, 1);
@@ -913,8 +919,6 @@ static void vop2_disable(struct vop2 *vop2)
 
 	pm_runtime_put_sync(vop2->dev);
 
-	regcache_mark_dirty(vop2->map);
-
 	clk_disable_unprepare(vop2->aclk);
 	clk_disable_unprepare(vop2->hclk);
 }