phy: improved lookup method (b7bc15b9) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/phy.txt

+16 −44

Original line number	Diff line number	Diff line
		@@ -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 +133,18 @@ 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 be made during runtime when a handle to
		the struct phy already exists.

		The framework offers the following API for registering and unregistering the
		lookups.

		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);

		9. DeviceTree Binding

drivers/phy/phy-core.c

+83 −1

Original line number	Diff line number	Diff line
		@@ -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 +85,87 @@ static struct phy phy_lookup(struct device device, const char *port)
		return ERR_PTR(-ENODEV);
		}

		/**
		* 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->dev_id = dev_id;
		pl->con_id = con_id;
		pl->phy = phy;

		mutex_lock(&phy_provider_mutex);
		list_add_tail(&pl->node, &phys);
		mutex_unlock(&phy_provider_mutex);

		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;

		mutex_lock(&phy_provider_mutex);
		list_for_each_entry(pl, &phys, node)
		if (pl->phy == phy && !strcmp(pl->dev_id, dev_id) &&
		!strcmp(pl->con_id, con_id)) {
		list_del(&pl->node);
		kfree(pl);
		break;
		}
		mutex_unlock(&phy_provider_mutex);
		}
		EXPORT_SYMBOL_GPL(phy_remove_lookup);

		static struct phy phy_find(struct device dev, const char *con_id)
		{
		const char *dev_id = dev_name(dev);
		struct phy_lookup p, pl = NULL;
		struct phy *phy;

		mutex_lock(&phy_provider_mutex);
		list_for_each_entry(p, &phys, node)
		if (!strcmp(p->dev_id, dev_id) && !strcmp(p->con_id, con_id)) {
		pl = p;
		break;
		}
		mutex_unlock(&phy_provider_mutex);

		phy = pl ? pl->phy : ERR_PTR(-ENODEV);

		/* 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;
		@@ -455,7 +537,7 @@ 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;

include/linux/phy/phy.h

+16 −0

Original line number	Diff line number	Diff line
		@@ -110,6 +110,13 @@ struct phy_init_data {
		.port = _port, \
		}

		struct phy_lookup {
		struct list_head node;
		const char *dev_id;
		const char *con_id;
		struct phy *phy;
		};

		#define to_phy(a) (container_of((a), struct phy, dev))

		#define of_phy_provider_register(dev, xlate) \
		@@ -174,6 +181,8 @@ 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);
		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 +354,13 @@ static inline void devm_of_phy_provider_unregister(struct device *dev,
		struct phy_provider *phy_provider)
		{
		}
		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 */