[PATCH 3/6] 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 used 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 power domains and
using them for gdsc control.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/clk/qcom/common.c | 55 ++++++++++++++++++++++++++++++++++-----
 drivers/clk/qcom/gdsc.c   |  6 +++++
 2 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index 60d2a78d1395..eeb5b8c93032 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -10,6 +10,8 @@
 #include <linux/clk-provider.h>
 #include <linux/reset-controller.h>
 #include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_runtime.h>
 
 #include "common.h"
 #include "clk-rcg.h"
@@ -76,6 +78,16 @@ qcom_cc_map(struct platform_device *pdev, const struct qcom_cc_desc *desc)
 	struct resource *res;
 	struct device *dev = &pdev->dev;
 
+	if (of_find_property(dev->of_node, "required-opps", NULL)) {
+		int pd_opp;
+
+		pd_opp = of_get_required_opp_performance_state(dev->of_node, 0);
+		if (pd_opp < 0)
+			return ERR_PTR(pd_opp);
+
+		dev_pm_genpd_set_performance_state(dev, pd_opp);
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(base))
@@ -224,6 +236,11 @@ 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)
 {
@@ -236,11 +253,28 @@ int qcom_cc_really_probe(struct platform_device *pdev,
 	struct clk_regmap **rclks = desc->clks;
 	size_t num_clk_hws = desc->num_clk_hws;
 	struct clk_hw **clk_hws = desc->clk_hws;
+	bool use_pm = false;
 
 	cc = devm_kzalloc(dev, sizeof(*cc), GFP_KERNEL);
 	if (!cc)
 		return -ENOMEM;
 
+	if (of_find_property(dev->of_node, "required-opps", NULL)) {
+		use_pm = true;
+
+		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)
+			return ret;
+	}
+
 	reset = &cc->reset;
 	reset->rcdev.of_node = dev->of_node;
 	reset->rcdev.ops = &qcom_reset_ops;
@@ -251,7 +285,7 @@ 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 +296,11 @@ 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 +311,7 @@ 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 +320,23 @@ 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;
+
+	if (use_pm)
+		pm_runtime_put(dev);
 
 	return 0;
+
+err:
+	if (use_pm)
+		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..40c384bda4fc 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/ktime.h>
 #include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/reset-controller.h>
@@ -237,6 +238,8 @@ static int gdsc_enable(struct generic_pm_domain *domain)
 	struct gdsc *sc = domain_to_gdsc(domain);
 	int ret;
 
+	pm_runtime_get_sync(domain->dev.parent);
+
 	if (sc->pwrsts == PWRSTS_ON)
 		return gdsc_deassert_reset(sc);
 
@@ -326,6 +329,8 @@ static int gdsc_disable(struct generic_pm_domain *domain)
 	if (sc->flags & CLAMP_IO)
 		gdsc_assert_clamp_io(sc);
 
+	pm_runtime_put(domain->dev.parent);
+
 	return 0;
 }
 
@@ -427,6 +432,7 @@ int gdsc_register(struct gdsc_desc *desc,
 			continue;
 		scs[i]->regmap = regmap;
 		scs[i]->rcdev = rcdev;
+		scs[i]->pd.dev.parent = desc->dev;
 		ret = gdsc_init(scs[i]);
 		if (ret)
 			return ret;
-- 
2.30.2