Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 947 insertions, 0 deletions

diff --git a/drivers/hte/hte.c b/drivers/hte/hte.c
new file mode 100644
index 0000000000..598a716b73
--- /dev/null
+++ b/drivers/hte/hte.c
@@ -0,0 +1,947 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021-2022 NVIDIA Corporation
+ *
+ * Author: Dipen Patel <dipenp@nvidia.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/hte.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+
+#define HTE_TS_NAME_LEN		10
+
+/* Global list of the HTE devices */
+static DEFINE_SPINLOCK(hte_lock);
+static LIST_HEAD(hte_devices);
+
+enum {
+	HTE_TS_REGISTERED,
+	HTE_TS_REQ,
+	HTE_TS_DISABLE,
+	HTE_TS_QUEUE_WK,
+};
+
+/**
+ * struct hte_ts_info - Information related to requested timestamp.
+ *
+ * @xlated_id: Timestamp ID as understood between HTE subsys and HTE provider,
+ * See xlate callback API.
+ * @flags: Flags holding state information.
+ * @hte_cb_flags: Callback related flags.
+ * @seq: Timestamp sequence counter.
+ * @line_name: HTE allocated line name.
+ * @free_attr_name: If set, free the attr name.
+ * @cb: A nonsleeping callback function provided by clients.
+ * @tcb: A secondary sleeping callback function provided by clients.
+ * @dropped_ts: Dropped timestamps.
+ * @slock: Spin lock to synchronize between disable/enable,
+ * request/release APIs.
+ * @cb_work: callback workqueue, used when tcb is specified.
+ * @req_mlock: Lock during timestamp request/release APIs.
+ * @ts_dbg_root: Root for the debug fs.
+ * @gdev: HTE abstract device that this timestamp information belongs to.
+ * @cl_data: Client specific data.
+ */
+struct hte_ts_info {
+	u32 xlated_id;
+	unsigned long flags;
+	unsigned long hte_cb_flags;
+	u64 seq;
+	char *line_name;
+	bool free_attr_name;
+	hte_ts_cb_t cb;
+	hte_ts_sec_cb_t tcb;
+	atomic_t dropped_ts;
+	spinlock_t slock;
+	struct work_struct cb_work;
+	struct mutex req_mlock;
+	struct dentry *ts_dbg_root;
+	struct hte_device *gdev;
+	void *cl_data;
+};
+
+/**
+ * struct hte_device - HTE abstract device
+ * @nlines: Number of entities this device supports.
+ * @ts_req: Total number of entities requested.
+ * @sdev: Device used at various debug prints.
+ * @dbg_root: Root directory for debug fs.
+ * @list: List node to store hte_device for each provider.
+ * @chip: HTE chip providing this HTE device.
+ * @owner: helps prevent removal of modules when in use.
+ * @ei: Timestamp information.
+ */
+struct hte_device {
+	u32 nlines;
+	atomic_t ts_req;
+	struct device *sdev;
+	struct dentry *dbg_root;
+	struct list_head list;
+	struct hte_chip *chip;
+	struct module *owner;
+	struct hte_ts_info ei[];
+};
+
+#ifdef CONFIG_DEBUG_FS
+
+static struct dentry *hte_root;
+
+static int __init hte_subsys_dbgfs_init(void)
+{
+	/* creates /sys/kernel/debug/hte/ */
+	hte_root = debugfs_create_dir("hte", NULL);
+
+	return 0;
+}
+subsys_initcall(hte_subsys_dbgfs_init);
+
+static void hte_chip_dbgfs_init(struct hte_device *gdev)
+{
+	const struct hte_chip *chip = gdev->chip;
+	const char *name = chip->name ? chip->name : dev_name(chip->dev);
+
+	gdev->dbg_root = debugfs_create_dir(name, hte_root);
+
+	debugfs_create_atomic_t("ts_requested", 0444, gdev->dbg_root,
+				&gdev->ts_req);
+	debugfs_create_u32("total_ts", 0444, gdev->dbg_root,
+			   &gdev->nlines);
+}
+
+static void hte_ts_dbgfs_init(const char *name, struct hte_ts_info *ei)
+{
+	if (!ei->gdev->dbg_root || !name)
+		return;
+
+	ei->ts_dbg_root = debugfs_create_dir(name, ei->gdev->dbg_root);
+
+	debugfs_create_atomic_t("dropped_timestamps", 0444, ei->ts_dbg_root,
+				&ei->dropped_ts);
+}
+
+#else
+
+static void hte_chip_dbgfs_init(struct hte_device *gdev)
+{
+}
+
+static void hte_ts_dbgfs_init(const char *name, struct hte_ts_info *ei)
+{
+}
+
+#endif
+
+/**
+ * hte_ts_put() - Release and disable timestamp for the given desc.
+ *
+ * @desc: timestamp descriptor.
+ *
+ * Context: debugfs_remove_recursive() function call may use sleeping locks,
+ *	    not suitable from atomic context.
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int hte_ts_put(struct hte_ts_desc *desc)
+{
+	int ret = 0;
+	unsigned long flag;
+	struct hte_device *gdev;
+	struct hte_ts_info *ei;
+
+	if (!desc)
+		return -EINVAL;
+
+	ei = desc->hte_data;
+
+	if (!ei || !ei->gdev)
+		return -EINVAL;
+
+	gdev = ei->gdev;
+
+	mutex_lock(&ei->req_mlock);
+
+	if (unlikely(!test_bit(HTE_TS_REQ, &ei->flags) &&
+	    !test_bit(HTE_TS_REGISTERED, &ei->flags))) {
+		dev_info(gdev->sdev, "id:%d is not requested\n",
+			 desc->attr.line_id);
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	if (unlikely(!test_bit(HTE_TS_REQ, &ei->flags) &&
+	    test_bit(HTE_TS_REGISTERED, &ei->flags))) {
+		dev_info(gdev->sdev, "id:%d is registered but not requested\n",
+			 desc->attr.line_id);
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	if (test_bit(HTE_TS_REQ, &ei->flags) &&
+	    !test_bit(HTE_TS_REGISTERED, &ei->flags)) {
+		clear_bit(HTE_TS_REQ, &ei->flags);
+		desc->hte_data = NULL;
+		ret = 0;
+		goto mod_put;
+	}
+
+	ret = gdev->chip->ops->release(gdev->chip, desc, ei->xlated_id);
+	if (ret) {
+		dev_err(gdev->sdev, "id: %d free failed\n",
+			desc->attr.line_id);
+		goto unlock;
+	}
+
+	kfree(ei->line_name);
+	if (ei->free_attr_name)
+		kfree_const(desc->attr.name);
+
+	debugfs_remove_recursive(ei->ts_dbg_root);
+
+	spin_lock_irqsave(&ei->slock, flag);
+
+	if (test_bit(HTE_TS_QUEUE_WK, &ei->flags)) {
+		spin_unlock_irqrestore(&ei->slock, flag);
+		flush_work(&ei->cb_work);
+		spin_lock_irqsave(&ei->slock, flag);
+	}
+
+	atomic_dec(&gdev->ts_req);
+	atomic_set(&ei->dropped_ts, 0);
+
+	ei->seq = 1;
+	ei->flags = 0;
+	desc->hte_data = NULL;
+
+	spin_unlock_irqrestore(&ei->slock, flag);
+
+	ei->cb = NULL;
+	ei->tcb = NULL;
+	ei->cl_data = NULL;
+
+mod_put:
+	module_put(gdev->owner);
+unlock:
+	mutex_unlock(&ei->req_mlock);
+	dev_dbg(gdev->sdev, "release id: %d\n", desc->attr.line_id);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hte_ts_put);
+
+static int hte_ts_dis_en_common(struct hte_ts_desc *desc, bool en)
+{
+	u32 ts_id;
+	struct hte_device *gdev;
+	struct hte_ts_info *ei;
+	int ret;
+	unsigned long flag;
+
+	if (!desc)
+		return -EINVAL;
+
+	ei = desc->hte_data;
+
+	if (!ei || !ei->gdev)
+		return -EINVAL;
+
+	gdev = ei->gdev;
+	ts_id = desc->attr.line_id;
+
+	mutex_lock(&ei->req_mlock);
+
+	if (!test_bit(HTE_TS_REGISTERED, &ei->flags)) {
+		dev_dbg(gdev->sdev, "id:%d is not registered", ts_id);
+		ret = -EUSERS;
+		goto out;
+	}
+
+	spin_lock_irqsave(&ei->slock, flag);
+
+	if (en) {
+		if (!test_bit(HTE_TS_DISABLE, &ei->flags)) {
+			ret = 0;
+			goto out_unlock;
+		}
+
+		spin_unlock_irqrestore(&ei->slock, flag);
+		ret = gdev->chip->ops->enable(gdev->chip, ei->xlated_id);
+		if (ret) {
+			dev_warn(gdev->sdev, "id: %d enable failed\n",
+				 ts_id);
+			goto out;
+		}
+
+		spin_lock_irqsave(&ei->slock, flag);
+		clear_bit(HTE_TS_DISABLE, &ei->flags);
+	} else {
+		if (test_bit(HTE_TS_DISABLE, &ei->flags)) {
+			ret = 0;
+			goto out_unlock;
+		}
+
+		spin_unlock_irqrestore(&ei->slock, flag);
+		ret = gdev->chip->ops->disable(gdev->chip, ei->xlated_id);
+		if (ret) {
+			dev_warn(gdev->sdev, "id: %d disable failed\n",
+				 ts_id);
+			goto out;
+		}
+
+		spin_lock_irqsave(&ei->slock, flag);
+		set_bit(HTE_TS_DISABLE, &ei->flags);
+	}
+
+out_unlock:
+	spin_unlock_irqrestore(&ei->slock, flag);
+out:
+	mutex_unlock(&ei->req_mlock);
+	return ret;
+}
+
+/**
+ * hte_disable_ts() - Disable timestamp on given descriptor.
+ *
+ * The API does not release any resources associated with desc.
+ *
+ * @desc: ts descriptor, this is the same as returned by the request API.
+ *
+ * Context: Holds mutex lock, not suitable from atomic context.
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int hte_disable_ts(struct hte_ts_desc *desc)
+{
+	return hte_ts_dis_en_common(desc, false);
+}
+EXPORT_SYMBOL_GPL(hte_disable_ts);
+
+/**
+ * hte_enable_ts() - Enable timestamp on given descriptor.
+ *
+ * @desc: ts descriptor, this is the same as returned by the request API.
+ *
+ * Context: Holds mutex lock, not suitable from atomic context.
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int hte_enable_ts(struct hte_ts_desc *desc)
+{
+	return hte_ts_dis_en_common(desc, true);
+}
+EXPORT_SYMBOL_GPL(hte_enable_ts);
+
+static void hte_do_cb_work(struct work_struct *w)
+{
+	unsigned long flag;
+	struct hte_ts_info *ei = container_of(w, struct hte_ts_info, cb_work);
+
+	if (unlikely(!ei->tcb))
+		return;
+
+	ei->tcb(ei->cl_data);
+
+	spin_lock_irqsave(&ei->slock, flag);
+	clear_bit(HTE_TS_QUEUE_WK, &ei->flags);
+	spin_unlock_irqrestore(&ei->slock, flag);
+}
+
+static int __hte_req_ts(struct hte_ts_desc *desc, hte_ts_cb_t cb,
+			hte_ts_sec_cb_t tcb, void *data)
+{
+	int ret;
+	struct hte_device *gdev;
+	struct hte_ts_info *ei = desc->hte_data;
+
+	gdev = ei->gdev;
+	/*
+	 * There is a chance that multiple consumers requesting same entity,
+	 * lock here.
+	 */
+	mutex_lock(&ei->req_mlock);
+
+	if (test_bit(HTE_TS_REGISTERED, &ei->flags) ||
+	    !test_bit(HTE_TS_REQ, &ei->flags)) {
+		dev_dbg(gdev->chip->dev, "id:%u req failed\n",
+			desc->attr.line_id);
+		ret = -EUSERS;
+		goto unlock;
+	}
+
+	ei->cb = cb;
+	ei->tcb = tcb;
+	if (tcb)
+		INIT_WORK(&ei->cb_work, hte_do_cb_work);
+
+	ret = gdev->chip->ops->request(gdev->chip, desc, ei->xlated_id);
+	if (ret < 0) {
+		dev_err(gdev->chip->dev, "ts request failed\n");
+		goto unlock;
+	}
+
+	ei->cl_data = data;
+	ei->seq = 1;
+
+	atomic_inc(&gdev->ts_req);
+
+	ei->line_name = NULL;
+	if (!desc->attr.name) {
+		ei->line_name = kzalloc(HTE_TS_NAME_LEN, GFP_KERNEL);
+		if (ei->line_name)
+			scnprintf(ei->line_name, HTE_TS_NAME_LEN, "ts_%u",
+				  desc->attr.line_id);
+	}
+
+	hte_ts_dbgfs_init(desc->attr.name == NULL ?
+			  ei->line_name : desc->attr.name, ei);
+	set_bit(HTE_TS_REGISTERED, &ei->flags);
+
+	dev_dbg(gdev->chip->dev, "id: %u, xlated id:%u",
+		desc->attr.line_id, ei->xlated_id);
+
+	ret = 0;
+
+unlock:
+	mutex_unlock(&ei->req_mlock);
+
+	return ret;
+}
+
+static int hte_bind_ts_info_locked(struct hte_ts_info *ei,
+				   struct hte_ts_desc *desc, u32 x_id)
+{
+	int ret = 0;
+
+	mutex_lock(&ei->req_mlock);
+
+	if (test_bit(HTE_TS_REQ, &ei->flags)) {
+		dev_dbg(ei->gdev->chip->dev, "id:%u is already requested\n",
+			desc->attr.line_id);
+		ret = -EUSERS;
+		goto out;
+	}
+
+	set_bit(HTE_TS_REQ, &ei->flags);
+	desc->hte_data = ei;
+	ei->xlated_id = x_id;
+
+out:
+	mutex_unlock(&ei->req_mlock);
+
+	return ret;
+}
+
+static struct hte_device *of_node_to_htedevice(struct device_node *np)
+{
+	struct hte_device *gdev;
+
+	spin_lock(&hte_lock);
+
+	list_for_each_entry(gdev, &hte_devices, list)
+		if (gdev->chip && gdev->chip->dev &&
+		    device_match_of_node(gdev->chip->dev, np)) {
+			spin_unlock(&hte_lock);
+			return gdev;
+		}
+
+	spin_unlock(&hte_lock);
+
+	return ERR_PTR(-ENODEV);
+}
+
+static struct hte_device *hte_find_dev_from_linedata(struct hte_ts_desc *desc)
+{
+	struct hte_device *gdev;
+
+	spin_lock(&hte_lock);
+
+	list_for_each_entry(gdev, &hte_devices, list)
+		if (gdev->chip && gdev->chip->match_from_linedata) {
+			if (!gdev->chip->match_from_linedata(gdev->chip, desc))
+				continue;
+			spin_unlock(&hte_lock);
+			return gdev;
+		}
+
+	spin_unlock(&hte_lock);
+
+	return ERR_PTR(-ENODEV);
+}
+
+/**
+ * of_hte_req_count - Return the number of entities to timestamp.
+ *
+ * The function returns the total count of the requested entities to timestamp
+ * by parsing device tree.
+ *
+ * @dev: The HTE consumer.
+ *
+ * Returns: Positive number on success, -ENOENT if no entries,
+ * -EINVAL for other errors.
+ */
+int of_hte_req_count(struct device *dev)
+{
+	int count;
+
+	if (!dev || !dev->of_node)
+		return -EINVAL;
+
+	count = of_count_phandle_with_args(dev->of_node, "timestamps",
+					   "#timestamp-cells");
+
+	return count ? count : -ENOENT;
+}
+EXPORT_SYMBOL_GPL(of_hte_req_count);
+
+static inline struct hte_device *hte_get_dev(struct hte_ts_desc *desc)
+{
+	return hte_find_dev_from_linedata(desc);
+}
+
+static struct hte_device *hte_of_get_dev(struct device *dev,
+					 struct hte_ts_desc *desc,
+					 int index,
+					 struct of_phandle_args *args,
+					 bool *free_name)
+{
+	int ret;
+	struct device_node *np;
+	char *temp;
+
+	if (!dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	np = dev->of_node;
+
+	if (!of_property_present(np, "timestamp-names")) {
+		/* Let hte core construct it during request time */
+		desc->attr.name = NULL;
+	} else {
+		ret = of_property_read_string_index(np, "timestamp-names",
+						    index, &desc->attr.name);
+		if (ret) {
+			pr_err("can't parse \"timestamp-names\" property\n");
+			return ERR_PTR(ret);
+		}
+		*free_name = false;
+		if (desc->attr.name) {
+			temp = skip_spaces(desc->attr.name);
+			if (!*temp)
+				desc->attr.name = NULL;
+		}
+	}
+
+	ret = of_parse_phandle_with_args(np, "timestamps", "#timestamp-cells",
+					 index, args);
+	if (ret) {
+		pr_err("%s(): can't parse \"timestamps\" property\n",
+		       __func__);
+		return ERR_PTR(ret);
+	}
+
+	of_node_put(args->np);
+
+	return of_node_to_htedevice(args->np);
+}
+
+/**
+ * hte_ts_get() - The function to initialize and obtain HTE desc.
+ *
+ * The function initializes the consumer provided HTE descriptor. If consumer
+ * has device tree node, index is used to parse the line id and other details.
+ * The function needs to be called before using any request APIs.
+ *
+ * @dev: HTE consumer/client device, used in case of parsing device tree node.
+ * @desc: Pre-allocated timestamp descriptor.
+ * @index: The index will be used as an index to parse line_id from the
+ * device tree node if node is present.
+ *
+ * Context: Holds mutex lock.
+ * Returns: Returns 0 on success or negative error code on failure.
+ */
+int hte_ts_get(struct device *dev, struct hte_ts_desc *desc, int index)
+{
+	struct hte_device *gdev;
+	struct hte_ts_info *ei;
+	const struct fwnode_handle *fwnode;
+	struct of_phandle_args args;
+	u32 xlated_id;
+	int ret;
+	bool free_name = false;
+
+	if (!desc)
+		return -EINVAL;
+
+	fwnode = dev ? dev_fwnode(dev) : NULL;
+
+	if (is_of_node(fwnode))
+		gdev = hte_of_get_dev(dev, desc, index, &args, &free_name);
+	else
+		gdev = hte_get_dev(desc);
+
+	if (IS_ERR(gdev)) {
+		pr_err("%s() no hte dev found\n", __func__);
+		return PTR_ERR(gdev);
+	}
+
+	if (!try_module_get(gdev->owner))
+		return -ENODEV;
+
+	if (!gdev->chip) {
+		pr_err("%s(): requested id does not have provider\n",
+		       __func__);
+		ret = -ENODEV;
+		goto put;
+	}
+
+	if (is_of_node(fwnode)) {
+		if (!gdev->chip->xlate_of)
+			ret = -EINVAL;
+		else
+			ret = gdev->chip->xlate_of(gdev->chip, &args,
+						   desc, &xlated_id);
+	} else {
+		if (!gdev->chip->xlate_plat)
+			ret = -EINVAL;
+		else
+			ret = gdev->chip->xlate_plat(gdev->chip, desc,
+						     &xlated_id);
+	}
+
+	if (ret < 0)
+		goto put;
+
+	ei = &gdev->ei[xlated_id];
+
+	ret = hte_bind_ts_info_locked(ei, desc, xlated_id);
+	if (ret)
+		goto put;
+
+	ei->free_attr_name = free_name;
+
+	return 0;
+
+put:
+	module_put(gdev->owner);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hte_ts_get);
+
+static void __devm_hte_release_ts(void *res)
+{
+	hte_ts_put(res);
+}
+
+/**
+ * hte_request_ts_ns() - The API to request and enable hardware timestamp in
+ * nanoseconds.
+ *
+ * The entity is provider specific for example, GPIO lines, signals, buses
+ * etc...The API allocates necessary resources and enables the timestamp.
+ *
+ * @desc: Pre-allocated and initialized timestamp descriptor.
+ * @cb: Callback to push the timestamp data to consumer.
+ * @tcb: Optional callback. If its provided, subsystem initializes
+ * workqueue. It is called when cb returns HTE_RUN_SECOND_CB.
+ * @data: Client data, used during cb and tcb callbacks.
+ *
+ * Context: Holds mutex lock.
+ * Returns: Returns 0 on success or negative error code on failure.
+ */
+int hte_request_ts_ns(struct hte_ts_desc *desc, hte_ts_cb_t cb,
+		      hte_ts_sec_cb_t tcb, void *data)
+{
+	int ret;
+	struct hte_ts_info *ei;
+
+	if (!desc || !desc->hte_data || !cb)
+		return -EINVAL;
+
+	ei = desc->hte_data;
+	if (!ei || !ei->gdev)
+		return -EINVAL;
+
+	ret = __hte_req_ts(desc, cb, tcb, data);
+	if (ret < 0) {
+		dev_err(ei->gdev->chip->dev,
+			"failed to request id: %d\n", desc->attr.line_id);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hte_request_ts_ns);
+
+/**
+ * devm_hte_request_ts_ns() - Resource managed API to request and enable
+ * hardware timestamp in nanoseconds.
+ *
+ * The entity is provider specific for example, GPIO lines, signals, buses
+ * etc...The API allocates necessary resources and enables the timestamp. It
+ * deallocates and disables automatically when the consumer exits.
+ *
+ * @dev: HTE consumer/client device.
+ * @desc: Pre-allocated and initialized timestamp descriptor.
+ * @cb: Callback to push the timestamp data to consumer.
+ * @tcb: Optional callback. If its provided, subsystem initializes
+ * workqueue. It is called when cb returns HTE_RUN_SECOND_CB.
+ * @data: Client data, used during cb and tcb callbacks.
+ *
+ * Context: Holds mutex lock.
+ * Returns: Returns 0 on success or negative error code on failure.
+ */
+int devm_hte_request_ts_ns(struct device *dev, struct hte_ts_desc *desc,
+			   hte_ts_cb_t cb, hte_ts_sec_cb_t tcb,
+			   void *data)
+{
+	int err;
+
+	if (!dev)
+		return -EINVAL;
+
+	err = hte_request_ts_ns(desc, cb, tcb, data);
+	if (err)
+		return err;
+
+	err = devm_add_action_or_reset(dev, __devm_hte_release_ts, desc);
+	if (err)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_hte_request_ts_ns);
+
+/**
+ * hte_init_line_attr() - Initialize line attributes.
+ *
+ * Zeroes out line attributes and initializes with provided arguments.
+ * The function needs to be called before calling any consumer facing
+ * functions.
+ *
+ * @desc: Pre-allocated timestamp descriptor.
+ * @line_id: line id.
+ * @edge_flags: edge flags related to line_id.
+ * @name: name of the line.
+ * @data: line data related to line_id.
+ *
+ * Context: Any.
+ * Returns: 0 on success or negative error code for the failure.
+ */
+int hte_init_line_attr(struct hte_ts_desc *desc, u32 line_id,
+		       unsigned long edge_flags, const char *name, void *data)
+{
+	if (!desc)
+		return -EINVAL;
+
+	memset(&desc->attr, 0, sizeof(desc->attr));
+
+	desc->attr.edge_flags = edge_flags;
+	desc->attr.line_id = line_id;
+	desc->attr.line_data = data;
+	if (name) {
+		name =  kstrdup_const(name, GFP_KERNEL);
+		if (!name)
+			return -ENOMEM;
+	}
+
+	desc->attr.name = name;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hte_init_line_attr);
+
+/**
+ * hte_get_clk_src_info() - Get the clock source information for a ts
+ * descriptor.
+ *
+ * @desc: ts descriptor, same as returned from request API.
+ * @ci: The API fills this structure with the clock information data.
+ *
+ * Context: Any context.
+ * Returns: 0 on success else negative error code on failure.
+ */
+int hte_get_clk_src_info(const struct hte_ts_desc *desc,
+			 struct hte_clk_info *ci)
+{
+	struct hte_chip *chip;
+	struct hte_ts_info *ei;
+
+	if (!desc || !desc->hte_data || !ci) {
+		pr_debug("%s:%d\n", __func__, __LINE__);
+		return -EINVAL;
+	}
+
+	ei = desc->hte_data;
+	if (!ei->gdev || !ei->gdev->chip)
+		return -EINVAL;
+
+	chip = ei->gdev->chip;
+	if (!chip->ops->get_clk_src_info)
+		return -EOPNOTSUPP;
+
+	return chip->ops->get_clk_src_info(chip, ci);
+}
+EXPORT_SYMBOL_GPL(hte_get_clk_src_info);
+
+/**
+ * hte_push_ts_ns() - Push timestamp data in nanoseconds.
+ *
+ * It is used by the provider to push timestamp data.
+ *
+ * @chip: The HTE chip, used during the registration.
+ * @xlated_id: entity id understood by both subsystem and provider, this is
+ * obtained from xlate callback during request API.
+ * @data: timestamp data.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int hte_push_ts_ns(const struct hte_chip *chip, u32 xlated_id,
+		   struct hte_ts_data *data)
+{
+	enum hte_return ret;
+	int st = 0;
+	struct hte_ts_info *ei;
+	unsigned long flag;
+
+	if (!chip || !data || !chip->gdev)
+		return -EINVAL;
+
+	if (xlated_id >= chip->nlines)
+		return -EINVAL;
+
+	ei = &chip->gdev->ei[xlated_id];
+
+	spin_lock_irqsave(&ei->slock, flag);
+
+	/* timestamp sequence counter */
+	data->seq = ei->seq++;
+
+	if (!test_bit(HTE_TS_REGISTERED, &ei->flags) ||
+	    test_bit(HTE_TS_DISABLE, &ei->flags)) {
+		dev_dbg(chip->dev, "Unknown timestamp push\n");
+		atomic_inc(&ei->dropped_ts);
+		st = -EINVAL;
+		goto unlock;
+	}
+
+	ret = ei->cb(data, ei->cl_data);
+	if (ret == HTE_RUN_SECOND_CB && ei->tcb) {
+		queue_work(system_unbound_wq, &ei->cb_work);
+		set_bit(HTE_TS_QUEUE_WK, &ei->flags);
+	}
+
+unlock:
+	spin_unlock_irqrestore(&ei->slock, flag);
+
+	return st;
+}
+EXPORT_SYMBOL_GPL(hte_push_ts_ns);
+
+static int hte_register_chip(struct hte_chip *chip)
+{
+	struct hte_device *gdev;
+	u32 i;
+
+	if (!chip || !chip->dev || !chip->dev->of_node)
+		return -EINVAL;
+
+	if (!chip->ops || !chip->ops->request || !chip->ops->release) {
+		dev_err(chip->dev, "Driver needs to provide ops\n");
+		return -EINVAL;
+	}
+
+	gdev = kzalloc(struct_size(gdev, ei, chip->nlines), GFP_KERNEL);
+	if (!gdev)
+		return -ENOMEM;
+
+	gdev->chip = chip;
+	chip->gdev = gdev;
+	gdev->nlines = chip->nlines;
+	gdev->sdev = chip->dev;
+
+	for (i = 0; i < chip->nlines; i++) {
+		gdev->ei[i].gdev = gdev;
+		mutex_init(&gdev->ei[i].req_mlock);
+		spin_lock_init(&gdev->ei[i].slock);
+	}
+
+	if (chip->dev->driver)
+		gdev->owner = chip->dev->driver->owner;
+	else
+		gdev->owner = THIS_MODULE;
+
+	of_node_get(chip->dev->of_node);
+
+	INIT_LIST_HEAD(&gdev->list);
+
+	spin_lock(&hte_lock);
+	list_add_tail(&gdev->list, &hte_devices);
+	spin_unlock(&hte_lock);
+
+	hte_chip_dbgfs_init(gdev);
+
+	dev_dbg(chip->dev, "Added hte chip\n");
+
+	return 0;
+}
+
+static int hte_unregister_chip(struct hte_chip *chip)
+{
+	struct hte_device *gdev;
+
+	if (!chip)
+		return -EINVAL;
+
+	gdev = chip->gdev;
+
+	spin_lock(&hte_lock);
+	list_del(&gdev->list);
+	spin_unlock(&hte_lock);
+
+	gdev->chip = NULL;
+
+	of_node_put(chip->dev->of_node);
+	debugfs_remove_recursive(gdev->dbg_root);
+	kfree(gdev);
+
+	dev_dbg(chip->dev, "Removed hte chip\n");
+
+	return 0;
+}
+
+static void _hte_devm_unregister_chip(void *chip)
+{
+	hte_unregister_chip(chip);
+}
+
+/**
+ * devm_hte_register_chip() - Resource managed API to register HTE chip.
+ *
+ * It is used by the provider to register itself with the HTE subsystem.
+ * The unregistration is done automatically when the provider exits.
+ *
+ * @chip: the HTE chip to add to subsystem.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int devm_hte_register_chip(struct hte_chip *chip)
+{
+	int err;
+
+	err = hte_register_chip(chip);
+	if (err)
+		return err;
+
+	err = devm_add_action_or_reset(chip->dev, _hte_devm_unregister_chip,
+				       chip);
+	if (err)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_hte_register_chip);