1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c
new file mode 100644
index 000000000000..146b81f08a89
--- /dev/null
+++ b/drivers/net/pse-pd/pse_core.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Framework for Ethernet Power Sourcing Equipment
+//
+// Copyright (c) 2022 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+//
+
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/pse-pd/pse.h>
+
+static DEFINE_MUTEX(pse_list_mutex);
+static LIST_HEAD(pse_controller_list);
+
+/**
+ * struct pse_control - a PSE control
+ * @pcdev: a pointer to the PSE controller device
+ *         this PSE control belongs to
+ * @list: list entry for the pcdev's PSE controller list
+ * @id: ID of the PSE line in the PSE controller device
+ * @refcnt: Number of gets of this pse_control
+ */
+struct pse_control {
+	struct pse_controller_dev *pcdev;
+	struct list_head list;
+	unsigned int id;
+	struct kref refcnt;
+};
+
+/**
+ * of_pse_zero_xlate - dummy function for controllers with one only control
+ * @pcdev: a pointer to the PSE controller device
+ * @pse_spec: PSE line specifier as found in the device tree
+ *
+ * This static translation function is used by default if of_xlate in
+ * :c:type:`pse_controller_dev` is not set. It is useful for all PSE
+ * controllers with #pse-cells = <0>.
+ */
+static int of_pse_zero_xlate(struct pse_controller_dev *pcdev,
+			     const struct of_phandle_args *pse_spec)
+{
+	return 0;
+}
+
+/**
+ * of_pse_simple_xlate - translate pse_spec to the PSE line number
+ * @pcdev: a pointer to the PSE controller device
+ * @pse_spec: PSE line specifier as found in the device tree
+ *
+ * This static translation function is used by default if of_xlate in
+ * :c:type:`pse_controller_dev` is not set. It is useful for all PSE
+ * controllers with 1:1 mapping, where PSE lines can be indexed by number
+ * without gaps.
+ */
+static int of_pse_simple_xlate(struct pse_controller_dev *pcdev,
+			       const struct of_phandle_args *pse_spec)
+{
+	if (pse_spec->args[0] >= pcdev->nr_lines)
+		return -EINVAL;
+
+	return pse_spec->args[0];
+}
+
+/**
+ * pse_controller_register - register a PSE controller device
+ * @pcdev: a pointer to the initialized PSE controller device
+ */
+int pse_controller_register(struct pse_controller_dev *pcdev)
+{
+	if (!pcdev->of_xlate) {
+		if (pcdev->of_pse_n_cells == 0)
+			pcdev->of_xlate = of_pse_zero_xlate;
+		else if (pcdev->of_pse_n_cells == 1)
+			pcdev->of_xlate = of_pse_simple_xlate;
+	}
+
+	mutex_init(&pcdev->lock);
+	INIT_LIST_HEAD(&pcdev->pse_control_head);
+
+	mutex_lock(&pse_list_mutex);
+	list_add(&pcdev->list, &pse_controller_list);
+	mutex_unlock(&pse_list_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pse_controller_register);
+
+/**
+ * pse_controller_unregister - unregister a PSE controller device
+ * @pcdev: a pointer to the PSE controller device
+ */
+void pse_controller_unregister(struct pse_controller_dev *pcdev)
+{
+	mutex_lock(&pse_list_mutex);
+	list_del(&pcdev->list);
+	mutex_unlock(&pse_list_mutex);
+}
+EXPORT_SYMBOL_GPL(pse_controller_unregister);
+
+static void devm_pse_controller_release(struct device *dev, void *res)
+{
+	pse_controller_unregister(*(struct pse_controller_dev **)res);
+}
+
+/**
+ * devm_pse_controller_register - resource managed pse_controller_register()
+ * @dev: device that is registering this PSE controller
+ * @pcdev: a pointer to the initialized PSE controller device
+ *
+ * Managed pse_controller_register(). For PSE controllers registered by
+ * this function, pse_controller_unregister() is automatically called on
+ * driver detach. See pse_controller_register() for more information.
+ */
+int devm_pse_controller_register(struct device *dev,
+				 struct pse_controller_dev *pcdev)
+{
+	struct pse_controller_dev **pcdevp;
+	int ret;
+
+	pcdevp = devres_alloc(devm_pse_controller_release, sizeof(*pcdevp),
+			      GFP_KERNEL);
+	if (!pcdevp)
+		return -ENOMEM;
+
+	ret = pse_controller_register(pcdev);
+	if (ret) {
+		devres_free(pcdevp);
+		return ret;
+	}
+
+	*pcdevp = pcdev;
+	devres_add(dev, pcdevp);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_pse_controller_register);
+
+/* PSE control section */
+
+static void __pse_control_release(struct kref *kref)
+{
+	struct pse_control *psec = container_of(kref, struct pse_control,
+						  refcnt);
+
+	lockdep_assert_held(&pse_list_mutex);
+
+	module_put(psec->pcdev->owner);
+
+	list_del(&psec->list);
+	kfree(psec);
+}
+
+static void __pse_control_put_internal(struct pse_control *psec)
+{
+	lockdep_assert_held(&pse_list_mutex);
+
+	kref_put(&psec->refcnt, __pse_control_release);
+}
+
+/**
+ * pse_control_put - free the PSE control
+ * @psec: PSE control pointer
+ */
+void pse_control_put(struct pse_control *psec)
+{
+	if (IS_ERR_OR_NULL(psec))
+		return;
+
+	mutex_lock(&pse_list_mutex);
+	__pse_control_put_internal(psec);
+	mutex_unlock(&pse_list_mutex);
+}
+EXPORT_SYMBOL_GPL(pse_control_put);
+
+static struct pse_control *
+pse_control_get_internal(struct pse_controller_dev *pcdev, unsigned int index)
+{
+	struct pse_control *psec;
+
+	lockdep_assert_held(&pse_list_mutex);
+
+	list_for_each_entry(psec, &pcdev->pse_control_head, list) {
+		if (psec->id == index) {
+			kref_get(&psec->refcnt);
+			return psec;
+		}
+	}
+
+	psec = kzalloc(sizeof(*psec), GFP_KERNEL);
+	if (!psec)
+		return ERR_PTR(-ENOMEM);
+
+	if (!try_module_get(pcdev->owner)) {
+		kfree(psec);
+		return ERR_PTR(-ENODEV);
+	}
+
+	psec->pcdev = pcdev;
+	list_add(&psec->list, &pcdev->pse_control_head);
+	psec->id = index;
+	kref_init(&psec->refcnt);
+
+	return psec;
+}
+
+struct pse_control *
+of_pse_control_get(struct device_node *node)
+{
+	struct pse_controller_dev *r, *pcdev;
+	struct of_phandle_args args;
+	struct pse_control *psec;
+	int psec_id;
+	int ret;
+
+	if (!node)
+		return ERR_PTR(-EINVAL);
+
+	ret = of_parse_phandle_with_args(node, "pses", "#pse-cells", 0, &args);
+	if (ret)
+		return ERR_PTR(ret);
+
+	mutex_lock(&pse_list_mutex);
+	pcdev = NULL;
+	list_for_each_entry(r, &pse_controller_list, list) {
+		if (args.np == r->dev->of_node) {
+			pcdev = r;
+			break;
+		}
+	}
+
+	if (!pcdev) {
+		psec = ERR_PTR(-EPROBE_DEFER);
+		goto out;
+	}
+
+	if (WARN_ON(args.args_count != pcdev->of_pse_n_cells)) {
+		psec = ERR_PTR(-EINVAL);
+		goto out;
+	}
+
+	psec_id = pcdev->of_xlate(pcdev, &args);
+	if (psec_id < 0) {
+		psec = ERR_PTR(psec_id);
+		goto out;
+	}
+
+	/* pse_list_mutex also protects the pcdev's pse_control list */
+	psec = pse_control_get_internal(pcdev, psec_id);
+
+out:
+	mutex_unlock(&pse_list_mutex);
+	of_node_put(args.np);
+
+	return psec;
+}
+EXPORT_SYMBOL_GPL(of_pse_control_get);
+
+/**
+ * pse_ethtool_get_status - get status of PSE control
+ * @psec: PSE control pointer
+ * @extack: extack for reporting useful error messages
+ * @status: struct to store PSE status
+ */
+int pse_ethtool_get_status(struct pse_control *psec,
+			   struct netlink_ext_ack *extack,
+			   struct pse_control_status *status)
+{
+	const struct pse_controller_ops *ops;
+	int err;
+
+	ops = psec->pcdev->ops;
+
+	if (!ops->ethtool_get_status) {
+		NL_SET_ERR_MSG(extack,
+			       "PSE driver does not support status report");
+		return -EOPNOTSUPP;
+	}
+
+	mutex_lock(&psec->pcdev->lock);
+	err = ops->ethtool_get_status(psec->pcdev, psec->id, extack, status);
+	mutex_unlock(&psec->pcdev->lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(pse_ethtool_get_status);
+
+/**
+ * pse_ethtool_set_config - set PSE control configuration
+ * @psec: PSE control pointer
+ * @extack: extack for reporting useful error messages
+ * @config: Configuration of the test to run
+ */
+int pse_ethtool_set_config(struct pse_control *psec,
+			   struct netlink_ext_ack *extack,
+			   const struct pse_control_config *config)
+{
+	const struct pse_controller_ops *ops;
+	int err;
+
+	ops = psec->pcdev->ops;
+
+	if (!ops->ethtool_set_config) {
+		NL_SET_ERR_MSG(extack,
+			       "PSE driver does not configuration");
+		return -EOPNOTSUPP;
+	}
+
+	mutex_lock(&psec->pcdev->lock);
+	err = ops->ethtool_set_config(psec->pcdev, psec->id, extack, config);
+	mutex_unlock(&psec->pcdev->lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(pse_ethtool_set_config);