drm/bridge: analogix_dp: Ensure edp is disabled when shutting down the panel

When panel is shut down, we should make sure edp can be disabled to avoid
undefined behavior.

Cc: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: zain wang <wzz@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-8-enric.balletbo@collabora.com

drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

@@ -1160,6 +1160,12 @@ static int analogix_dp_set_bridge(struct analogix_dp_device *dp)
 
 	pm_runtime_get_sync(dp->dev);
 
+	ret = clk_prepare_enable(dp->clock);
+	if (ret < 0) {
+		DRM_ERROR("Failed to prepare_enable the clock clk [%d]\n", ret);
+		goto out_dp_clk_pre;
+	}
+
 	if (dp->plat_data->power_on)
 		dp->plat_data->power_on(dp->plat_data);
 
@@ -1191,6 +1197,8 @@ out_dp_init:
 	phy_power_off(dp->phy);
 	if (dp->plat_data->power_off)
 		dp->plat_data->power_off(dp->plat_data);
+	clk_disable_unprepare(dp->clock);
+out_dp_clk_pre:
 	pm_runtime_put_sync(dp->dev);
 
 	return ret;
@@ -1233,11 +1241,14 @@ static void analogix_dp_bridge_disable(struct drm_bridge *bridge)
 	}
 
 	disable_irq(dp->irq);
+	analogix_dp_set_analog_power_down(dp, POWER_ALL, 1);
 	phy_power_off(dp->phy);
 
 	if (dp->plat_data->power_off)
 		dp->plat_data->power_off(dp->plat_data);
 
+	clk_disable_unprepare(dp->clock);
+
 	pm_runtime_put_sync(dp->dev);
 
 	ret = analogix_dp_prepare_panel(dp, false, true);