[PATCH 4/5] clk: qcom: common: Register clk_ref clocks from qcom_cc_desc

[Stanislav Aleksandrov <lightofmysoul@gmail.com>]

The clk_ref clocks model a clkref_en gate together with the supplies of
the QREF block that feeds it. So far they can only be registered as a
standalone clock provider with qcom_clk_ref_probe(), as on the TCSR of
X1E80100 and Glymur.

On Halliday the clkref_en registers are part of GCC, and the QREF
supplies are shared with the UFS PHY: when UFS runtime suspend turns
them off, the USB HS PHY loses its reference clock. The GCC driver
needs to provide its clkrefs as clk_ref clocks next to its other
clocks, so that their users keep the supplies on.

Let a qcom_cc_desc carry clk_ref descriptions, indexed by clock ID like
its other clocks. qcom_clk_ref_register() now registers a single clock,
so qcom_cc_really_probe() allocates and registers only the populated
entries, and qcom_cc_clk_hw_get() returns them for their indices. As
with the other clocks, entries listed in protected-clocks are skipped.
A clock ID used by both a clk_ref and a regmap clock fails the probe.

Signed-off-by: Stanislav Aleksandrov <lightofmysoul@gmail.com>
---
 drivers/clk/qcom/clk-ref.c | 91 +++++++++++++++++++++-------------------------
 drivers/clk/qcom/common.c  | 60 ++++++++++++++++++++++++++++++
 drivers/clk/qcom/common.h  |  9 +++++
 3 files changed, 110 insertions(+), 50 deletions(-)

diff --git a/drivers/clk/qcom/clk-ref.c b/drivers/clk/qcom/clk-ref.c
index 3efdf6749770..266acdfa5488 100644
--- a/drivers/clk/qcom/clk-ref.c
+++ b/drivers/clk/qcom/clk-ref.c
@@ -13,6 +13,8 @@
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
+#include "common.h"
+
 #define QCOM_CLK_REF_EN_MASK BIT(0)
 
 struct qcom_clk_ref_provider {
@@ -96,63 +98,46 @@ static const struct clk_ops qcom_clk_ref_ops = {
 	.is_enabled = qcom_clk_ref_is_enabled,
 };
 
-static int qcom_clk_ref_register(struct device *dev, struct regmap *regmap,
-				 struct qcom_clk_ref *clk_refs,
-				 const struct qcom_clk_ref_desc * const *descs,
-				 size_t num_clk_refs)
+int qcom_clk_ref_register(struct device *dev, struct regmap *regmap,
+			  struct qcom_clk_ref *clk_ref,
+			  const struct qcom_clk_ref_desc *desc)
 {
-	const struct qcom_clk_ref_desc *desc;
 	struct clk_init_data init_data = {};
-	struct qcom_clk_ref *clk_ref;
-	size_t clk_idx;
 	unsigned int i;
 	int ret;
 
-	for (clk_idx = 0; clk_idx < num_clk_refs; clk_idx++) {
-		clk_ref = &clk_refs[clk_idx];
-		desc = descs[clk_idx];
+	if (WARN_ON(!desc->name))
+		return -EINVAL;
 
-		/* Skip unpopulated indices; the array is indexed by clock ID. */
-		if (!desc)
-			continue;
+	clk_ref->regmap = regmap;
+	clk_ref->desc = *desc;
 
-		if (WARN_ON(!desc->name))
-			continue;
+	if (clk_ref->desc.num_regulators) {
+		clk_ref->regulators = devm_kcalloc(dev, clk_ref->desc.num_regulators,
+						   sizeof(*clk_ref->regulators),
+						   GFP_KERNEL);
+		if (!clk_ref->regulators)
+			return -ENOMEM;
 
-		clk_ref->regmap = regmap;
-		clk_ref->desc = *desc;
-
-		if (clk_ref->desc.num_regulators) {
-			clk_ref->regulators = devm_kcalloc(dev, clk_ref->desc.num_regulators,
-							   sizeof(*clk_ref->regulators),
-							   GFP_KERNEL);
-			if (!clk_ref->regulators)
-				return -ENOMEM;
-
-			for (i = 0; i < clk_ref->desc.num_regulators; i++)
-				clk_ref->regulators[i].supply =
-					clk_ref->desc.regulator_names[i];
-
-			ret = devm_regulator_bulk_get(dev, clk_ref->desc.num_regulators,
-						      clk_ref->regulators);
-			if (ret)
-				return dev_err_probe(dev, ret,
-						     "Failed to get regulators for %s\n",
-						     clk_ref->desc.name);
-		}
-
-		init_data.name = clk_ref->desc.name;
-		init_data.parent_data = &qcom_clk_ref_parent_data;
-		init_data.num_parents = 1;
-		init_data.ops = &qcom_clk_ref_ops;
-		clk_ref->hw.init = &init_data;
-
-		ret = devm_clk_hw_register(dev, &clk_ref->hw);
+		for (i = 0; i < clk_ref->desc.num_regulators; i++)
+			clk_ref->regulators[i].supply =
+				clk_ref->desc.regulator_names[i];
+
+		ret = devm_regulator_bulk_get(dev, clk_ref->desc.num_regulators,
+					      clk_ref->regulators);
 		if (ret)
-			return ret;
+			return dev_err_probe(dev, ret,
+					     "Failed to get regulators for %s\n",
+					     clk_ref->desc.name);
 	}
 
-	return 0;
+	init_data.name = clk_ref->desc.name;
+	init_data.parent_data = &qcom_clk_ref_parent_data;
+	init_data.num_parents = 1;
+	init_data.ops = &qcom_clk_ref_ops;
+	clk_ref->hw.init = &init_data;
+
+	return devm_clk_hw_register(dev, &clk_ref->hw);
 }
 
 static struct clk_hw *qcom_clk_ref_provider_get(struct of_phandle_args *clkspec, void *data)
@@ -178,6 +163,7 @@ int qcom_clk_ref_probe(struct platform_device *pdev,
 	struct device *dev = &pdev->dev;
 	struct regmap *regmap;
 	void __iomem *base;
+	size_t i;
 	int ret;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
@@ -195,10 +181,15 @@ int qcom_clk_ref_probe(struct platform_device *pdev,
 
 	provider->num_refs = num_clk_refs;
 
-	ret = qcom_clk_ref_register(dev, regmap, provider->refs, descs,
-				    provider->num_refs);
-	if (ret)
-		return ret;
+	for (i = 0; i < num_clk_refs; i++) {
+		/* Skip unpopulated indices; the array is indexed by clock ID. */
+		if (!descs[i])
+			continue;
+
+		ret = qcom_clk_ref_register(dev, regmap, &provider->refs[i], descs[i]);
+		if (ret)
+			return ret;
+	}
 
 	return devm_of_clk_add_hw_provider(dev, qcom_clk_ref_provider_get, provider);
 }
diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index 08fd62ac780d..c767fa3d0207 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -8,6 +8,7 @@
 #include <linux/regmap.h>
 #include <linux/platform_device.h>
 #include <linux/clk-provider.h>
+#include <linux/clk/qcom.h>
 #include <linux/interconnect-clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset-controller.h>
@@ -25,6 +26,8 @@ struct qcom_cc {
 	struct qcom_reset_controller reset;
 	struct clk_regmap **rclks;
 	size_t num_rclks;
+	struct qcom_clk_ref **clk_refs;
+	size_t num_clk_refs;
 	struct dev_pm_domain_list *pd_list;
 };
 
@@ -247,6 +250,9 @@ static struct clk_hw *qcom_cc_clk_hw_get(struct of_phandle_args *clkspec,
 	struct qcom_cc *cc = data;
 	unsigned int idx = clkspec->args[0];
 
+	if (idx < cc->num_clk_refs && cc->clk_refs[idx])
+		return &cc->clk_refs[idx]->hw;
+
 	if (idx >= cc->num_rclks) {
 		pr_err("%s: invalid index %u\n", __func__, idx);
 		return ERR_PTR(-EINVAL);
@@ -255,6 +261,54 @@ static struct clk_hw *qcom_cc_clk_hw_get(struct of_phandle_args *clkspec,
 	return cc->rclks[idx] ? &cc->rclks[idx]->hw : NULL;
 }
 
+static bool qcom_cc_is_protected(struct device *dev, unsigned int idx)
+{
+	u32 i;
+
+	of_property_for_each_u32(dev->of_node, "protected-clocks", i) {
+		if (i == idx)
+			return true;
+	}
+
+	return false;
+}
+
+static int qcom_cc_register_clk_refs(struct device *dev, struct qcom_cc *cc,
+				     const struct qcom_cc_desc *desc,
+				     struct regmap *regmap)
+{
+	struct qcom_clk_ref *clk_ref;
+	size_t i;
+	int ret;
+
+	cc->clk_refs = devm_kcalloc(dev, desc->num_clk_refs, sizeof(*cc->clk_refs),
+				    GFP_KERNEL);
+	if (!cc->clk_refs)
+		return -ENOMEM;
+
+	cc->num_clk_refs = desc->num_clk_refs;
+
+	for (i = 0; i < desc->num_clk_refs; i++) {
+		if (!desc->clk_refs[i] || qcom_cc_is_protected(dev, i))
+			continue;
+
+		if (WARN_ON(i < desc->num_clks && desc->clks[i]))
+			return -EINVAL;
+
+		clk_ref = devm_kzalloc(dev, sizeof(*clk_ref), GFP_KERNEL);
+		if (!clk_ref)
+			return -ENOMEM;
+
+		ret = qcom_clk_ref_register(dev, regmap, clk_ref, desc->clk_refs[i]);
+		if (ret)
+			return ret;
+
+		cc->clk_refs[i] = clk_ref;
+	}
+
+	return 0;
+}
+
 static int qcom_cc_icc_register(struct device *dev,
 				const struct qcom_cc_desc *desc)
 {
@@ -359,6 +413,12 @@ int qcom_cc_really_probe(struct device *dev,
 		qcom_cc_clk_regs_configure(dev, desc->driver_data, regmap);
 	}
 
+	if (desc->num_clk_refs) {
+		ret = qcom_cc_register_clk_refs(dev, cc, desc, regmap);
+		if (ret)
+			goto put_rpm;
+	}
+
 	reset = &cc->reset;
 	reset->rcdev.of_node = dev->of_node;
 	reset->rcdev.ops = &qcom_reset_ops;
diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h
index 6f2406f8839e..438fe5be56e1 100644
--- a/drivers/clk/qcom/common.h
+++ b/drivers/clk/qcom/common.h
@@ -19,6 +19,9 @@ struct clk_hw;
 #define PLL_VOTE_FSM_ENA	BIT(20)
 #define PLL_VOTE_FSM_RESET	BIT(21)
 
+struct qcom_clk_ref;
+struct qcom_clk_ref_desc;
+
 struct qcom_icc_hws_data {
 	int master_id;
 	int slave_id;
@@ -45,6 +48,8 @@ struct qcom_cc_desc {
 	size_t num_gdscs;
 	struct clk_hw **clk_hws;
 	size_t num_clk_hws;
+	const struct qcom_clk_ref_desc * const *clk_refs;
+	size_t num_clk_refs;
 	const struct qcom_icc_hws_data *icc_hws;
 	size_t num_icc_hws;
 	unsigned int icc_first_node_id;
@@ -89,4 +94,8 @@ extern int qcom_cc_probe(struct platform_device *pdev,
 extern int qcom_cc_probe_by_index(struct platform_device *pdev, int index,
 				  const struct qcom_cc_desc *desc);
 
+int qcom_clk_ref_register(struct device *dev, struct regmap *regmap,
+			  struct qcom_clk_ref *clk_ref,
+			  const struct qcom_clk_ref_desc *desc);
+
 #endif

-- 
2.55.0