drm/mediatek: mtk_dsi: Reset the dsi0 hardware

[ Upstream commit 605c837 ]

Reset dsi0 HW to default when power on. This prevents to have different
settingis between the bootloader and the kernel.

As not all Mediatek boards have the reset consumer configured in their
board description, also is not needed on all of them, the reset is optional,
so the change is compatible with all boards.

Cc: Jitao Shi <jitao.shi@mediatek.com>
Suggested-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20210930103105.v4.7.Idbb4727ddf00ba2fe796b630906baff10d994d89@changeid
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/mediatek/mtk_dsi.c

@@ -11,6 +11,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 
 #include <video/mipi_display.h>
 #include <video/videomode.h>
@@ -980,8 +981,10 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
 	ret = mtk_dsi_encoder_init(drm, dsi);
+	if (ret)
+		return ret;
 
-	return ret;
+	return device_reset_optional(dev);
 }
 
 static void mtk_dsi_unbind(struct device *dev, struct device *master,