[PATCH v3 3/7] clk: qcom: gdsc: enable optional power domain support

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On sm8250 dispcc and videocc registers are powered up by the MMCX power
domain. Currently we use a regulator to enable this domain on demand,
however this has some consequences, as genpd code is not reentrant.

Teach Qualcomm clock controller code about setting up runtime PM and
using specified for gdsc powerup.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/clk/qcom/common.c | 37 +++++++++++++++++++++++++++++++------
 drivers/clk/qcom/gdsc.c   |  4 ++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index 60d2a78d1395..43d8f8feeb3c 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -10,6 +10,7 @@
 #include <linux/clk-provider.h>
 #include <linux/reset-controller.h>
 #include <linux/of.h>
+#include <linux/pm_runtime.h>
 
 #include "common.h"
 #include "clk-rcg.h"
@@ -224,6 +225,11 @@ static struct clk_hw *qcom_cc_clk_hw_get(struct of_phandle_args *clkspec,
 	return cc->rclks[idx] ? &cc->rclks[idx]->hw : NULL;
 }
 
+static void qcom_cc_pm_runtime_disable(void *data)
+{
+	pm_runtime_disable(data);
+}
+
 int qcom_cc_really_probe(struct platform_device *pdev,
 			 const struct qcom_cc_desc *desc, struct regmap *regmap)
 {
@@ -241,6 +247,18 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 	if (!cc)
 		return -ENOMEM;
 
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put(dev);
+		pm_runtime_disable(dev);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, qcom_cc_pm_runtime_disable, dev);
+	if (ret)
+		goto err;
+
 	reset = &cc->reset;
 	reset->rcdev.of_node = dev->of_node;
 	reset->rcdev.ops = &qcom_reset_ops;
@@ -251,7 +269,7 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 
 	ret = devm_reset_controller_register(dev, &reset->rcdev);
 	if (ret)
-		return ret;
+		goto err;
 
 	if (desc->gdscs && desc->num_gdscs) {
 		scd = devm_kzalloc(dev, sizeof(*scd), GFP_KERNEL);
@@ -262,11 +280,11 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 		scd->num = desc->num_gdscs;
 		ret = gdsc_register(scd, &reset->rcdev, regmap);
 		if (ret)
-			return ret;
+			goto err;
 		ret = devm_add_action_or_reset(dev, qcom_cc_gdsc_unregister,
 					       scd);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	cc->rclks = rclks;
@@ -277,7 +295,7 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 	for (i = 0; i < num_clk_hws; i++) {
 		ret = devm_clk_hw_register(dev, clk_hws[i]);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	for (i = 0; i < num_clks; i++) {
@@ -286,14 +304,21 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 
 		ret = devm_clk_register_regmap(dev, rclks[i]);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	ret = devm_of_clk_add_hw_provider(dev, qcom_cc_clk_hw_get, cc);
 	if (ret)
-		return ret;
+		goto err;
+
+	pm_runtime_put(dev);
 
 	return 0;
+
+err:
+	pm_runtime_put(dev);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_cc_really_probe);
 
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index 51ed640e527b..ccd36617d067 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -439,6 +439,8 @@ int gdsc_register(struct gdsc_desc *desc,
 			continue;
 		if (scs[i]->parent)
 			pm_genpd_add_subdomain(scs[i]->parent, &scs[i]->pd);
+		else if (!IS_ERR_OR_NULL(dev->pm_domain))
+			pm_genpd_add_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
 	}
 
 	return of_genpd_add_provider_onecell(dev->of_node, data);
@@ -457,6 +459,8 @@ void gdsc_unregister(struct gdsc_desc *desc)
 			continue;
 		if (scs[i]->parent)
 			pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd);
+		else if (!IS_ERR_OR_NULL(dev->pm_domain))
+			pm_genpd_remove_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
 	}
 	of_genpd_del_provider(dev->of_node);
 }
-- 
2.30.2