1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/net/phy/phy_package.c b/drivers/net/phy/phy_package.c
new file mode 100644
index 000000000000..260469f027c8
--- /dev/null
+++ b/drivers/net/phy/phy_package.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PHY package support
+ */
+
+#include <linux/of.h>
+#include <linux/phy.h>
+
+/**
+ * phy_package_join - join a common PHY group
+ * @phydev: target phy_device struct
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ *   calculation of global register access
+ * @priv_size: if non-zero allocate this amount of bytes for private data
+ *
+ * This joins a PHY group and provides a shared storage for all phydevs in
+ * this group. This is intended to be used for packages which contain
+ * more than one PHY, for example a quad PHY transceiver.
+ *
+ * The base_addr parameter serves as cookie which has to have the same values
+ * for all members of one group and as the base PHY address of the PHY package
+ * for offset calculation to access generic registers of a PHY package.
+ * Usually, one of the PHY addresses of the different PHYs in the package
+ * provides access to these global registers.
+ * The address which is given here, will be used in the phy_package_read()
+ * and phy_package_write() convenience functions as base and added to the
+ * passed offset in those functions.
+ *
+ * This will set the shared pointer of the phydev to the shared storage.
+ * If this is the first call for a this cookie the shared storage will be
+ * allocated. If priv_size is non-zero, the given amount of bytes are
+ * allocated for the priv member.
+ *
+ * Returns < 1 on error, 0 on success. Esp. calling phy_package_join()
+ * with the same cookie but a different priv_size is an error.
+ */
+int phy_package_join(struct phy_device *phydev, int base_addr, size_t priv_size)
+{
+	struct mii_bus *bus = phydev->mdio.bus;
+	struct phy_package_shared *shared;
+	int ret;
+
+	if (base_addr < 0 || base_addr >= PHY_MAX_ADDR)
+		return -EINVAL;
+
+	mutex_lock(&bus->shared_lock);
+	shared = bus->shared[base_addr];
+	if (!shared) {
+		ret = -ENOMEM;
+		shared = kzalloc(sizeof(*shared), GFP_KERNEL);
+		if (!shared)
+			goto err_unlock;
+		if (priv_size) {
+			shared->priv = kzalloc(priv_size, GFP_KERNEL);
+			if (!shared->priv)
+				goto err_free;
+			shared->priv_size = priv_size;
+		}
+		shared->base_addr = base_addr;
+		shared->np = NULL;
+		refcount_set(&shared->refcnt, 1);
+		bus->shared[base_addr] = shared;
+	} else {
+		ret = -EINVAL;
+		if (priv_size && priv_size != shared->priv_size)
+			goto err_unlock;
+		refcount_inc(&shared->refcnt);
+	}
+	mutex_unlock(&bus->shared_lock);
+
+	phydev->shared = shared;
+
+	return 0;
+
+err_free:
+	kfree(shared);
+err_unlock:
+	mutex_unlock(&bus->shared_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_package_join);
+
+/**
+ * of_phy_package_join - join a common PHY group in PHY package
+ * @phydev: target phy_device struct
+ * @priv_size: if non-zero allocate this amount of bytes for private data
+ *
+ * This is a variant of phy_package_join for PHY package defined in DT.
+ *
+ * The parent node of the @phydev is checked as a valid PHY package node
+ * structure (by matching the node name "ethernet-phy-package") and the
+ * base_addr for the PHY package is passed to phy_package_join.
+ *
+ * With this configuration the shared struct will also have the np value
+ * filled to use additional DT defined properties in PHY specific
+ * probe_once and config_init_once PHY package OPs.
+ *
+ * Returns < 0 on error, 0 on success. Esp. calling phy_package_join()
+ * with the same cookie but a different priv_size is an error. Or a parent
+ * node is not detected or is not valid or doesn't match the expected node
+ * name for PHY package.
+ */
+int of_phy_package_join(struct phy_device *phydev, size_t priv_size)
+{
+	struct device_node *node = phydev->mdio.dev.of_node;
+	struct device_node *package_node;
+	u32 base_addr;
+	int ret;
+
+	if (!node)
+		return -EINVAL;
+
+	package_node = of_get_parent(node);
+	if (!package_node)
+		return -EINVAL;
+
+	if (!of_node_name_eq(package_node, "ethernet-phy-package")) {
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	if (of_property_read_u32(package_node, "reg", &base_addr)) {
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	ret = phy_package_join(phydev, base_addr, priv_size);
+	if (ret)
+		goto exit;
+
+	phydev->shared->np = package_node;
+
+	return 0;
+exit:
+	of_node_put(package_node);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_phy_package_join);
+
+/**
+ * phy_package_leave - leave a common PHY group
+ * @phydev: target phy_device struct
+ *
+ * This leaves a PHY group created by phy_package_join(). If this phydev
+ * was the last user of the shared data between the group, this data is
+ * freed. Resets the phydev->shared pointer to NULL.
+ */
+void phy_package_leave(struct phy_device *phydev)
+{
+	struct phy_package_shared *shared = phydev->shared;
+	struct mii_bus *bus = phydev->mdio.bus;
+
+	if (!shared)
+		return;
+
+	/* Decrease the node refcount on leave if present */
+	if (shared->np)
+		of_node_put(shared->np);
+
+	if (refcount_dec_and_mutex_lock(&shared->refcnt, &bus->shared_lock)) {
+		bus->shared[shared->base_addr] = NULL;
+		mutex_unlock(&bus->shared_lock);
+		kfree(shared->priv);
+		kfree(shared);
+	}
+
+	phydev->shared = NULL;
+}
+EXPORT_SYMBOL_GPL(phy_package_leave);
+
+static void devm_phy_package_leave(struct device *dev, void *res)
+{
+	phy_package_leave(*(struct phy_device **)res);
+}
+
+/**
+ * devm_phy_package_join - resource managed phy_package_join()
+ * @dev: device that is registering this PHY package
+ * @phydev: target phy_device struct
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ *   calculation of global register access
+ * @priv_size: if non-zero allocate this amount of bytes for private data
+ *
+ * Managed phy_package_join(). Shared storage fetched by this function,
+ * phy_package_leave() is automatically called on driver detach. See
+ * phy_package_join() for more information.
+ */
+int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
+			  int base_addr, size_t priv_size)
+{
+	struct phy_device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_phy_package_leave, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = phy_package_join(phydev, base_addr, priv_size);
+
+	if (!ret) {
+		*ptr = phydev;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_phy_package_join);
+
+/**
+ * devm_of_phy_package_join - resource managed of_phy_package_join()
+ * @dev: device that is registering this PHY package
+ * @phydev: target phy_device struct
+ * @priv_size: if non-zero allocate this amount of bytes for private data
+ *
+ * Managed of_phy_package_join(). Shared storage fetched by this function,
+ * phy_package_leave() is automatically called on driver detach. See
+ * of_phy_package_join() for more information.
+ */
+int devm_of_phy_package_join(struct device *dev, struct phy_device *phydev,
+			     size_t priv_size)
+{
+	struct phy_device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_phy_package_leave, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = of_phy_package_join(phydev, priv_size);
+
+	if (!ret) {
+		*ptr = phydev;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_of_phy_package_join);