[PATCHv4 2/6] phy: improved lookup method

[Heikki Krogerus]

Removes the need for the phys to be aware of their users
even when not using DT. The method is copied from clkdev.c.

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Tested-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
---
 Documentation/phy.txt   |  66 ++++++++---------------
 drivers/phy/phy-core.c  | 135 +++++++++++++++++++++++++++++++++++++++++++++++-
 include/linux/phy/phy.h |  27 ++++++++++
 3 files changed, 183 insertions(+), 45 deletions(-)

diff --git a/Documentation/phy.txt b/Documentation/phy.txt
index c6594af..8add515 100644
--- a/Documentation/phy.txt
+++ b/Documentation/phy.txt
@@ -54,18 +54,14 @@ The PHY driver should create the PHY in order for other peripheral controllers
 to make use of it. The PHY framework provides 2 APIs to create the PHY.
 
 struct phy *phy_create(struct device *dev, struct device_node *node,
-		       const struct phy_ops *ops,
-		       struct phy_init_data *init_data);
+		       const struct phy_ops *ops);
 struct phy *devm_phy_create(struct device *dev, struct device_node *node,
-			    const struct phy_ops *ops,
-			    struct phy_init_data *init_data);
+			    const struct phy_ops *ops);
 
 The PHY drivers can use one of the above 2 APIs to create the PHY by passing
-the device pointer, phy ops and init_data.
+the device pointer and phy ops.
 phy_ops is a set of function pointers for performing PHY operations such as
-init, exit, power_on and power_off. *init_data* is mandatory to get a reference
-to the PHY in the case of non-dt boot. See section *Board File Initialization*
-on how init_data should be used.
+init, exit, power_on and power_off.
 
 Inorder to dereference the private data (in phy_ops), the phy provider driver
 can use phy_set_drvdata() after creating the PHY and use phy_get_drvdata() in
@@ -137,42 +133,24 @@ There are exported APIs like phy_pm_runtime_get, phy_pm_runtime_get_sync,
 phy_pm_runtime_put, phy_pm_runtime_put_sync, phy_pm_runtime_allow and
 phy_pm_runtime_forbid for performing PM operations.
 
-8. Board File Initialization
-
-Certain board file initialization is necessary in order to get a reference
-to the PHY in the case of non-dt boot.
-Say we have a single device that implements 3 PHYs that of USB, SATA and PCIe,
-then in the board file the following initialization should be done.
-
-struct phy_consumer consumers[] = {
-	PHY_CONSUMER("dwc3.0", "usb"),
-	PHY_CONSUMER("pcie.0", "pcie"),
-	PHY_CONSUMER("sata.0", "sata"),
-};
-PHY_CONSUMER takes 2 parameters, first is the device name of the controller
-(PHY consumer) and second is the port name.
-
-struct phy_init_data init_data = {
-	.consumers = consumers,
-	.num_consumers = ARRAY_SIZE(consumers),
-};
-
-static const struct platform_device pipe3_phy_dev = {
-	.name = "pipe3-phy",
-	.id = -1,
-	.dev = {
-		.platform_data = {
-			.init_data = &init_data,
-		},
-	},
-};
-
-then, while doing phy_create, the PHY driver should pass this init_data
-	phy_create(dev, ops, pdata->init_data);
-
-and the controller driver (phy consumer) should pass the port name along with
-the device to get a reference to the PHY
-	phy_get(dev, "pcie");
+8. PHY Mappings
+
+In order to get reference to a PHY without help from DeviceTree, the framework
+offers lookups which can be compared to clkdev that allow clk structures to be
+bound to devices. A lookup can be made statically by directly registering
+phy_lookup structure which contains the name of the PHY device, the name of the
+device which the PHY will be bind to and Connection ID string. Alternatively a
+lookup can be made during runtime when a handle to the struct phy already
+exists.
+
+The framework offers the following APIs for registering and unregistering the
+lookups.
+
+void phy_register_lookup(struct phy_lookup *pl);
+int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id);
+
+void phy_unregister_lookup(struct phy_lookup *pl);
+void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id);
 
 9. DeviceTree Binding
 
diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index ff5eec5..c8d0f66 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -26,6 +26,7 @@
 static struct class *phy_class;
 static DEFINE_MUTEX(phy_provider_mutex);
 static LIST_HEAD(phy_provider_list);
+static LIST_HEAD(phys);
 static DEFINE_IDA(phy_ida);
 
 static void devm_phy_release(struct device *dev, void *res)
@@ -84,6 +85,138 @@ static struct phy *phy_lookup(struct device *device, const char *port)
 	return ERR_PTR(-ENODEV);
 }
 
+/**
+ * phy_register_lookup() - register PHY/device association
+ * @pl: association to register
+ */
+void phy_register_lookup(struct phy_lookup *pl)
+{
+	mutex_lock(&phy_provider_mutex);
+	list_add_tail(&pl->node, &phys);
+	mutex_unlock(&phy_provider_mutex);
+}
+
+/**
+ * phy_unregister_lookup() - remove PHY/device association
+ * @pl: association to be removed
+ */
+void phy_unregister_lookup(struct phy_lookup *pl)
+{
+	mutex_lock(&phy_provider_mutex);
+	list_del(&pl->node);
+	mutex_unlock(&phy_provider_mutex);
+}
+
+/**
+ * phy_create_lookup() - allocate and register PHY/device association
+ * @phy: the phy of the association
+ * @con_id: connection ID string on device
+ * @dev_id: the device of the association
+ *
+ * Creates and registers phy_lookup entry.
+ */
+int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id)
+{
+	struct phy_lookup *pl;
+
+	if (!phy || (!dev_id && !con_id))
+		return -EINVAL;
+
+	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
+	if (!pl)
+		return -ENOMEM;
+
+	pl->phy_name = dev_name(phy->dev.parent);
+	pl->dev_id = dev_id;
+	pl->con_id = con_id;
+
+	phy_register_lookup(pl);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(phy_create_lookup);
+
+/**
+ * phy_remove_lookup() - find and remove PHY/device association
+ * @phy: the phy of the association
+ * @con_id: connection ID string on device
+ * @dev_id: the device of the association
+ *
+ * Finds and unregisters phy_lookup entry that was created with
+ * phy_create_lookup().
+ */
+void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id)
+{
+	struct phy_lookup *pl;
+
+	if (!phy || (!dev_id && !con_id))
+		return;
+
+	list_for_each_entry(pl, &phys, node)
+		if (!strcmp(pl->phy_name, dev_name(phy->dev.parent)) &&
+		    !strcmp(pl->dev_id, dev_id) &&
+		    !strcmp(pl->con_id, con_id)) {
+			phy_unregister_lookup(pl);
+			kfree(pl);
+			return;
+		}
+}
+EXPORT_SYMBOL_GPL(phy_remove_lookup);
+
+static struct phy *phy_find(struct device *dev, const char *con_id)
+{
+	const char *dev_id = dev ? dev_name(dev) : NULL;
+	int match, best_found = 0, best_possible = 0;
+	struct phy *phy = ERR_PTR(-ENODEV);
+	struct phy_lookup *p, *pl = NULL;
+
+	if (dev_id)
+		best_possible += 2;
+	if (con_id)
+		best_possible += 1;
+
+	list_for_each_entry(p, &phys, node) {
+		match = 0;
+		if (p->dev_id) {
+			if (!dev_id || strcmp(p->dev_id, dev_id))
+				continue;
+			match += 2;
+		}
+		if (p->con_id) {
+			if (!con_id || strcmp(p->con_id, con_id))
+				continue;
+			match += 1;
+		}
+
+		if (match > best_found) {
+			pl = p;
+			if (match != best_possible)
+				best_found = match;
+			else
+				break;
+		}
+	}
+
+	if (pl) {
+		struct class_dev_iter iter;
+		struct device *phy_dev;
+
+		class_dev_iter_init(&iter, phy_class, NULL, NULL);
+		while ((phy_dev = class_dev_iter_next(&iter))) {
+			if (!strcmp(dev_name(phy_dev->parent), pl->phy_name)) {
+				phy = to_phy(phy_dev);
+				break;
+			}
+		}
+		class_dev_iter_exit(&iter);
+	}
+
+	/* fall-back to the old lookup method for now */
+	if (IS_ERR(phy))
+		phy = phy_lookup(dev, con_id);
+	return phy;
+}
+
 static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
 {
 	struct phy_provider *phy_provider;
@@ -463,7 +596,7 @@ struct phy *phy_get(struct device *dev, const char *string)
 			string);
 		phy = _of_phy_get(dev->of_node, index);
 	} else {
-		phy = phy_lookup(dev, string);
+		phy = phy_find(dev, string);
 	}
 	if (IS_ERR(phy))
 		return phy;
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 9fda683..2696b95 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -110,6 +110,20 @@ struct phy_init_data {
 	.port		= _port,				\
 }
 
+struct phy_lookup {
+	struct list_head node;
+	const char *phy_name;
+	const char *dev_id;
+	const char *con_id;
+};
+
+#define PHY_LOOKUP(a, b, c)	\
+	{				\
+		.phy_name = a,		\
+		.dev_id = b,		\
+		.con_id = c,		\
+	}
+
 #define	to_phy(a)	(container_of((a), struct phy, dev))
 
 #define	of_phy_provider_register(dev, xlate)	\
@@ -174,6 +188,10 @@ struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
 void of_phy_provider_unregister(struct phy_provider *phy_provider);
 void devm_of_phy_provider_unregister(struct device *dev,
 	struct phy_provider *phy_provider);
+void phy_register_lookup(struct phy_lookup *pl);
+void phy_unregister_lookup(struct phy_lookup *pl);
+int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id);
+void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id);
 #else
 static inline int phy_pm_runtime_get(struct phy *phy)
 {
@@ -345,6 +363,15 @@ static inline void devm_of_phy_provider_unregister(struct device *dev,
 	struct phy_provider *phy_provider)
 {
 }
+static inline void phy_register_lookup(struct phy_lookup *pl) { }
+static inline void phy_unregister_lookup(struct phy_lookup *pl) { }
+static inline int
+phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id)
+{
+	return 0;
+}
+static inline void phy_remove_lookup(struct phy *phy, const char *con_id,
+				     const char *dev_id) { }
 #endif
 
 #endif /* __DRIVERS_PHY_H */
-- 
2.1.1

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