--- /dev/null
+/*
+ * devfreq-event: a framework to provide raw data and events of devfreq devices
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This driver is based on drivers/devfreq/devfreq.c.
+ */
+
+#include <linux/devfreq-event.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/of.h>
+
+static struct class *devfreq_event_class;
+
+/* The list of all devfreq event list */
+static LIST_HEAD(devfreq_event_list);
+static DEFINE_MUTEX(devfreq_event_list_lock);
+
+#define to_devfreq_event(DEV) container_of(DEV, struct devfreq_event_dev, dev)
+
+/**
+ * devfreq_event_enable_edev() - Enable the devfreq-event dev and increase
+ * the enable_count of devfreq-event dev.
+ * @edev : the devfreq-event device
+ *
+ * Note that this function increase the enable_count and enable the
+ * devfreq-event device. The devfreq-event device should be enabled before
+ * using it by devfreq device.
+ */
+int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
+{
+ int ret = 0;
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ mutex_lock(&edev->lock);
+ if (edev->desc->ops && edev->desc->ops->enable
+ && edev->enable_count == 0) {
+ ret = edev->desc->ops->enable(edev);
+ if (ret < 0)
+ goto err;
+ }
+ edev->enable_count++;
+err:
+ mutex_unlock(&edev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_enable_edev);
+
+/**
+ * devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease
+ * the enable_count of the devfreq-event dev.
+ * @edev : the devfreq-event device
+ *
+ * Note that this function decrease the enable_count and disable the
+ * devfreq-event device. After the devfreq-event device is disabled,
+ * devfreq device can't use the devfreq-event device for get/set/reset
+ * operations.
+ */
+int devfreq_event_disable_edev(struct devfreq_event_dev *edev)
+{
+ int ret = 0;
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ mutex_lock(&edev->lock);
+ if (edev->enable_count <= 0) {
+ dev_warn(&edev->dev, "unbalanced enable_count\n");
+ ret = -EIO;
+ goto err;
+ }
+
+ if (edev->desc->ops && edev->desc->ops->disable
+ && edev->enable_count == 1) {
+ ret = edev->desc->ops->disable(edev);
+ if (ret < 0)
+ goto err;
+ }
+ edev->enable_count--;
+err:
+ mutex_unlock(&edev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_disable_edev);
+
+/**
+ * devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or
+ * not.
+ * @edev : the devfreq-event device
+ *
+ * Note that this function check whether devfreq-event dev is enabled or not.
+ * If return true, the devfreq-event dev is enabeld. If return false, the
+ * devfreq-event dev is disabled.
+ */
+bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
+{
+ bool enabled = false;
+
+ if (!edev || !edev->desc)
+ return enabled;
+
+ mutex_lock(&edev->lock);
+
+ if (edev->enable_count > 0)
+ enabled = true;
+
+ mutex_unlock(&edev->lock);
+
+ return enabled;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_is_enabled);
+
+/**
+ * devfreq_event_set_event() - Set event to devfreq-event dev to start.
+ * @edev : the devfreq-event device
+ *
+ * Note that this function set the event to the devfreq-event device to start
+ * for getting the event data which could be various event type.
+ */
+int devfreq_event_set_event(struct devfreq_event_dev *edev)
+{
+ int ret;
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ if (!edev->desc->ops || !edev->desc->ops->set_event)
+ return -EINVAL;
+
+ if (!devfreq_event_is_enabled(edev))
+ return -EPERM;
+
+ mutex_lock(&edev->lock);
+ ret = edev->desc->ops->set_event(edev);
+ mutex_unlock(&edev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_set_event);
+
+/**
+ * devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev.
+ * @edev : the devfreq-event device
+ * @edata : the calculated data of devfreq-event device
+ *
+ * Note that this function get the calculated event data from devfreq-event dev
+ * after stoping the progress of whole sequence of devfreq-event dev.
+ */
+int devfreq_event_get_event(struct devfreq_event_dev *edev,
+ struct devfreq_event_data *edata)
+{
+ int ret;
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ if (!edev->desc->ops || !edev->desc->ops->get_event)
+ return -EINVAL;
+
+ if (!devfreq_event_is_enabled(edev))
+ return -EINVAL;
+
+ edata->total_count = edata->load_count = 0;
+
+ mutex_lock(&edev->lock);
+ ret = edev->desc->ops->get_event(edev, edata);
+ if (ret < 0)
+ edata->total_count = edata->load_count = 0;
+ mutex_unlock(&edev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_event);
+
+/**
+ * devfreq_event_reset_event() - Reset all opeations of devfreq-event dev.
+ * @edev : the devfreq-event device
+ *
+ * Note that this function stop all operations of devfreq-event dev and reset
+ * the current event data to make the devfreq-event device into initial state.
+ */
+int devfreq_event_reset_event(struct devfreq_event_dev *edev)
+{
+ int ret = 0;
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ if (!devfreq_event_is_enabled(edev))
+ return -EPERM;
+
+ mutex_lock(&edev->lock);
+ if (edev->desc->ops && edev->desc->ops->reset)
+ ret = edev->desc->ops->reset(edev);
+ mutex_unlock(&edev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_reset_event);
+
+/**
+ * devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from
+ * devicetree.
+ * @dev : the pointer to the given device
+ * @index : the index into list of devfreq-event device
+ *
+ * Note that this function return the pointer of devfreq-event device.
+ */
+struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev,
+ int index)
+{
+ struct device_node *node;
+ struct devfreq_event_dev *edev;
+
+ if (!dev->of_node) {
+ dev_err(dev, "device does not have a device node entry\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ node = of_parse_phandle(dev->of_node, "devfreq-events", index);
+ if (!node) {
+ dev_err(dev, "failed to get phandle in %s node\n",
+ dev->of_node->full_name);
+ return ERR_PTR(-ENODEV);
+ }
+
+ mutex_lock(&devfreq_event_list_lock);
+ list_for_each_entry(edev, &devfreq_event_list, node) {
+ if (!strcmp(edev->desc->name, node->name))
+ goto out;
+ }
+ edev = NULL;
+out:
+ mutex_unlock(&devfreq_event_list_lock);
+
+ if (!edev) {
+ dev_err(dev, "unable to get devfreq-event device : %s\n",
+ node->name);
+ of_node_put(node);
+ return ERR_PTR(-ENODEV);
+ }
+
+ of_node_put(node);
+
+ return edev;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_edev_by_phandle);
+
+/**
+ * devfreq_event_get_edev_count() - Get the count of devfreq-event dev
+ * @dev : the pointer to the given device
+ *
+ * Note that this function return the count of devfreq-event devices.
+ */
+int devfreq_event_get_edev_count(struct device *dev)
+{
+ int count;
+
+ if (!dev->of_node) {
+ dev_err(dev, "device does not have a device node entry\n");
+ return -EINVAL;
+ }
+
+ count = of_property_count_elems_of_size(dev->of_node, "devfreq-events",
+ sizeof(u32));
+ if (count < 0 ) {
+ dev_err(dev,
+ "failed to get the count of devfreq-event in %s node\n",
+ dev->of_node->full_name);
+ return count;
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_edev_count);
+
+static void devfreq_event_release_edev(struct device *dev)
+{
+ struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+ kfree(edev);
+}
+
+/**
+ * devfreq_event_add_edev() - Add new devfreq-event device.
+ * @dev : the device owning the devfreq-event device being created
+ * @desc : the devfreq-event device's decriptor which include essential
+ * data for devfreq-event device.
+ *
+ * Note that this function add new devfreq-event device to devfreq-event class
+ * list and register the device of the devfreq-event device.
+ */
+struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
+ struct devfreq_event_desc *desc)
+{
+ struct devfreq_event_dev *edev;
+ static atomic_t event_no = ATOMIC_INIT(0);
+ int ret;
+
+ if (!dev || !desc)
+ return ERR_PTR(-EINVAL);
+
+ if (!desc->name || !desc->ops)
+ return ERR_PTR(-EINVAL);
+
+ if (!desc->ops->set_event || !desc->ops->get_event)
+ return ERR_PTR(-EINVAL);
+
+ edev = kzalloc(sizeof(struct devfreq_event_dev), GFP_KERNEL);
+ if (!edev)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&edev->lock);
+ edev->desc = desc;
+ edev->enable_count = 0;
+ edev->dev.parent = dev;
+ edev->dev.class = devfreq_event_class;
+ edev->dev.release = devfreq_event_release_edev;
+
+ dev_set_name(&edev->dev, "event.%d", atomic_inc_return(&event_no) - 1);
+ ret = device_register(&edev->dev);
+ if (ret < 0) {
+ put_device(&edev->dev);
+ return ERR_PTR(ret);
+ }
+ dev_set_drvdata(&edev->dev, edev);
+
+ INIT_LIST_HEAD(&edev->node);
+
+ mutex_lock(&devfreq_event_list_lock);
+ list_add(&edev->node, &devfreq_event_list);
+ mutex_unlock(&devfreq_event_list_lock);
+
+ return edev;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_add_edev);
+
+/**
+ * devfreq_event_remove_edev() - Remove the devfreq-event device registered.
+ * @dev : the devfreq-event device
+ *
+ * Note that this function remove the registered devfreq-event device.
+ */
+int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
+{
+ if (!edev)
+ return -EINVAL;
+
+ WARN_ON(edev->enable_count);
+
+ mutex_lock(&devfreq_event_list_lock);
+ list_del(&edev->node);
+ mutex_unlock(&devfreq_event_list_lock);
+
+ device_unregister(&edev->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
+
+static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
+{
+ struct devfreq_event_dev **r = res;
+
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ return *r == data;
+}
+
+static void devm_devfreq_event_release(struct device *dev, void *res)
+{
+ devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
+}
+
+/**
+ * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
+ * @dev : the device owning the devfreq-event device being created
+ * @desc : the devfreq-event device's decriptor which include essential
+ * data for devfreq-event device.
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management and simplify the free operation
+ * for memory of devfreq-event device.
+ */
+struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+ struct devfreq_event_desc *desc)
+{
+ struct devfreq_event_dev **ptr, *edev;
+
+ ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ edev = devfreq_event_add_edev(dev, desc);
+ if (IS_ERR(edev)) {
+ devres_free(ptr);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ *ptr = edev;
+ devres_add(dev, ptr);
+
+ return edev;
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
+
+/**
+ * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
+ * @dev : the device owning the devfreq-event device being created
+ * @edev : the devfreq-event device
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management.
+ */
+void devm_devfreq_event_remove_edev(struct device *dev,
+ struct devfreq_event_dev *edev)
+{
+ WARN_ON(devres_release(dev, devm_devfreq_event_release,
+ devm_devfreq_event_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
+
+/*
+ * Device attributes for devfreq-event class.
+ */
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ return sprintf(buf, "%s\n", edev->desc->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t enable_count_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+ if (!edev || !edev->desc)
+ return -EINVAL;
+
+ return sprintf(buf, "%d\n", edev->enable_count);
+}
+static DEVICE_ATTR_RO(enable_count);
+
+static struct attribute *devfreq_event_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_enable_count.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(devfreq_event);
+
+static int __init devfreq_event_init(void)
+{
+ devfreq_event_class = class_create(THIS_MODULE, "devfreq-event");
+ if (IS_ERR(devfreq_event_class)) {
+ pr_err("%s: couldn't create class\n", __FILE__);
+ return PTR_ERR(devfreq_event_class);
+ }
+
+ devfreq_event_class->dev_groups = devfreq_event_groups;
+
+ return 0;
+}
+subsys_initcall(devfreq_event_init);
+
+static void __exit devfreq_event_exit(void)
+{
+ class_destroy(devfreq_event_class);
+}
+module_exit(devfreq_event_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_DESCRIPTION("DEVFREQ-Event class support");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff