[PATCH v2 09/12] drm/bridge: synopsys: dw-dp: Add Runtime PM support

[Sebastian Reichel <sebastian.reichel@collabora.com>]

Add runtime PM stubs to the Synopsys DesignWare DisplayPort bridge
driver. Support is not enabled automatically and must be hooked up
in the vendor specific glue code.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-dp.c | 27 +++++++++++++++++++++++++++
 include/drm/bridge/dw_dp.h              |  3 +++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 7ade88f74466..b0ab2b3d478d 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1465,6 +1465,8 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
 	if (WARN_ON(msg->size > 16))
 		return -E2BIG;
 
+	ACQUIRE(pm_runtime_active_auto, pm)(dp->dev);
+
 	switch (msg->request & ~DP_AUX_I2C_MOT) {
 	case DP_AUX_NATIVE_WRITE:
 	case DP_AUX_I2C_WRITE:
@@ -1655,6 +1657,8 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
 	struct drm_connector_state *conn_state;
 	int ret;
 
+	pm_runtime_get_sync(dp->dev);
+
 	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
 	if (!connector) {
 		dev_err(dp->dev, "failed to get connector\n");
@@ -1709,6 +1713,7 @@ static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
 	dw_dp_link_disable(dp);
 	bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
 	dw_dp_reset(dp);
+	pm_runtime_put_autosuspend(dp->dev);
 }
 
 static bool dw_dp_hpd_detect_link(struct dw_dp *dp, struct drm_connector *connector)
@@ -1729,6 +1734,8 @@ static enum drm_connector_status dw_dp_bridge_detect(struct drm_bridge *bridge,
 {
 	struct dw_dp *dp = bridge_to_dp(bridge);
 
+	ACQUIRE(pm_runtime_active_auto, pm)(dp->dev);
+
 	if (!dw_dp_hpd_detect(dp))
 		return connector_status_disconnected;
 
@@ -2153,6 +2160,26 @@ void dw_dp_unbind(struct dw_dp *dp)
 }
 EXPORT_SYMBOL_GPL(dw_dp_unbind);
 
+int dw_dp_runtime_suspend(struct dw_dp *dp)
+{
+	clk_disable_unprepare(dp->aux_clk);
+	clk_disable_unprepare(dp->apb_clk);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_suspend);
+
+int dw_dp_runtime_resume(struct dw_dp *dp)
+{
+	clk_prepare_enable(dp->apb_clk);
+	clk_prepare_enable(dp->aux_clk);
+
+	dw_dp_init_hw(dp);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_resume);
+
 MODULE_AUTHOR("Andy Yan <andyshrk@163.com>");
 MODULE_DESCRIPTION("DW DP Core Library");
 MODULE_LICENSE("GPL");
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index 2127afa26b2c..3037e0290861 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -28,4 +28,7 @@ struct dw_dp_plat_data {
 struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
 			 const struct dw_dp_plat_data *plat_data);
 void dw_dp_unbind(struct dw_dp *dp);
+
+int dw_dp_runtime_suspend(struct dw_dp *dp);
+int dw_dp_runtime_resume(struct dw_dp *dp);
 #endif /* __DW_DP__ */

-- 
2.53.0