disp: msm: vote for reg bus during rsc pm_runtime events

Add reg bus vote separate for RSC on top of the SDE
driver vote during the pm_runtime suspend/resume
events to avoid register access issues.

Change-Id: Ifbaead747b7b10db107696c8cce8e1ecfae5e0f8
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>

msm/sde_rsc.c

@@ -16,6 +16,7 @@
 #include <linux/of_platform.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/msm-bus.h>
 
 #include <soc/qcom/rpmh.h>
 #include <drm/drmP.h>
@@ -1317,6 +1318,7 @@ static int sde_rsc_runtime_suspend(struct device *dev)
 {
 	struct sde_rsc_priv *rsc = dev_get_drvdata(dev);
 	struct dss_module_power *mp;
+	u32 reg_bus_hdl;
 
 	if (!rsc) {
 		pr_err("invalid drv data\n");
@@ -1325,6 +1327,10 @@ static int sde_rsc_runtime_suspend(struct device *dev)
 
 	mp = &rsc->phandle.mp;
 	msm_dss_enable_clk(mp->clk_config, mp->num_clk, false);
+	reg_bus_hdl = rsc->phandle.reg_bus_hdl;
+	if (reg_bus_hdl)
+		msm_bus_scale_client_update_request(reg_bus_hdl,
+				VOTE_INDEX_DISABLE);
 	msm_dss_enable_vreg(mp->vreg_config, mp->num_vreg, false);
 
 	return 0;
@@ -1335,6 +1341,7 @@ static int sde_rsc_runtime_resume(struct device *dev)
 	struct sde_rsc_priv *rsc = dev_get_drvdata(dev);
 	struct dss_module_power *mp;
 	int rc = 0;
+	u32 reg_bus_hdl;
 
 	if (!rsc) {
 		pr_err("invalid drv data\n");
@@ -1348,12 +1355,30 @@ static int sde_rsc_runtime_resume(struct device *dev)
 		goto end;
 	}
 
+	reg_bus_hdl = rsc->phandle.reg_bus_hdl;
+	if (reg_bus_hdl) {
+		rc = msm_bus_scale_client_update_request(reg_bus_hdl,
+				VOTE_INDEX_LOW);
+		if (rc) {
+			pr_err("failed to set reg bus vote rc=%d\n", rc);
+			goto reg_bus_hdl_err;
+		}
+	}
+
 	rc = msm_dss_enable_clk(mp->clk_config, mp->num_clk, true);
 	if (rc) {
 		pr_err("clock enable failed rc:%d\n", rc);
-		msm_dss_enable_vreg(mp->vreg_config, mp->num_vreg, false);
+		goto clk_err;
 	}
 
+	return rc;
+
+clk_err:
+	if (reg_bus_hdl)
+		msm_bus_scale_client_update_request(reg_bus_hdl,
+				VOTE_INDEX_DISABLE);
+reg_bus_hdl_err:
+	msm_dss_enable_vreg(mp->vreg_config, mp->num_vreg, false);
 end:
 	return rc;
 }