[RFC PATCH 07/10] drm/bridge: ps8640: require manual DSI power control

[Dmitry Baryshkov]

The Parade PS8640 bridge will fail to start if the DSI link is enabled
when the bridge is being reset / powered up (even to the LP-11 state).
To ensure that the DSI link is powered down, require manual control over
the DSI link state.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/bridge/parade-ps8640.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 8161b1a1a4b1..6c5daaa70cb7 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -458,6 +458,10 @@ static void ps8640_atomic_pre_enable(struct drm_bridge *bridge,
 
 	ps8640_bridge_vdo_control(ps_bridge, ENABLE);
 
+	ret = mipi_dsi_host_power_up(ps_bridge->dsi->host);
+	if (ret < 0)
+		dev_warn(dev, "failed to power up DSI host: %d\n", ret);
+
 	ps_bridge->pre_enabled = true;
 }
 
@@ -468,6 +472,8 @@ static void ps8640_atomic_post_disable(struct drm_bridge *bridge,
 
 	ps_bridge->pre_enabled = false;
 
+	mipi_dsi_host_power_down(ps_bridge->dsi->host);
+
 	ps8640_bridge_vdo_control(ps_bridge, DISABLE);
 	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
 }
@@ -562,6 +568,11 @@ static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps
 	if (!host)
 		return -EPROBE_DEFER;
 
+	if (!mipi_dsi_host_power_control_available(host)) {
+		dev_err(dev, "MIPI DSI host doesn't provide tight power control\n");
+		return -ENODEV;
+	}
+
 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
 	if (IS_ERR(dsi)) {
 		dev_err(dev, "failed to create dsi device\n");
@@ -572,7 +583,8 @@ static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps
 
 	dsi->host = host;
 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
-			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+			  MIPI_DSI_MANUAL_POWERUP;
 	dsi->format = MIPI_DSI_FMT_RGB888;
 	dsi->lanes = NUM_MIPI_LANES;
 
-- 
2.42.0