483 lines
12 KiB
C
483 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* devfreq-event: a framework to provide raw data and events of devfreq devices
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*
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* Copyright (C) 2015 Samsung Electronics
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* Author: Chanwoo Choi <cw00.choi@samsung.com>
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*
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* This driver is based on drivers/devfreq/devfreq.c.
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*/
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#include <linux/devfreq-event.h>
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/of.h>
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static struct class *devfreq_event_class;
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/* The list of all devfreq event list */
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static LIST_HEAD(devfreq_event_list);
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static DEFINE_MUTEX(devfreq_event_list_lock);
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#define to_devfreq_event(DEV) container_of(DEV, struct devfreq_event_dev, dev)
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/**
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* devfreq_event_enable_edev() - Enable the devfreq-event dev and increase
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* the enable_count of devfreq-event dev.
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* @edev : the devfreq-event device
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*
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* Note that this function increase the enable_count and enable the
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* devfreq-event device. The devfreq-event device should be enabled before
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* using it by devfreq device.
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*/
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int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
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{
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int ret = 0;
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if (!edev || !edev->desc)
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return -EINVAL;
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mutex_lock(&edev->lock);
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if (edev->desc->ops && edev->desc->ops->enable
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&& edev->enable_count == 0) {
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ret = edev->desc->ops->enable(edev);
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if (ret < 0)
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goto err;
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}
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edev->enable_count++;
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err:
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mutex_unlock(&edev->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_enable_edev);
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/**
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* devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease
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* the enable_count of the devfreq-event dev.
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* @edev : the devfreq-event device
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*
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* Note that this function decrease the enable_count and disable the
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* devfreq-event device. After the devfreq-event device is disabled,
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* devfreq device can't use the devfreq-event device for get/set/reset
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* operations.
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*/
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int devfreq_event_disable_edev(struct devfreq_event_dev *edev)
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{
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int ret = 0;
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if (!edev || !edev->desc)
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return -EINVAL;
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mutex_lock(&edev->lock);
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if (edev->enable_count <= 0) {
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dev_warn(&edev->dev, "unbalanced enable_count\n");
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ret = -EIO;
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goto err;
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}
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if (edev->desc->ops && edev->desc->ops->disable
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&& edev->enable_count == 1) {
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ret = edev->desc->ops->disable(edev);
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if (ret < 0)
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goto err;
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}
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edev->enable_count--;
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err:
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mutex_unlock(&edev->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_disable_edev);
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/**
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* devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or
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* not.
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* @edev : the devfreq-event device
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*
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* Note that this function check whether devfreq-event dev is enabled or not.
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* If return true, the devfreq-event dev is enabeld. If return false, the
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* devfreq-event dev is disabled.
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*/
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bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
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{
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bool enabled = false;
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if (!edev || !edev->desc)
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return enabled;
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mutex_lock(&edev->lock);
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if (edev->enable_count > 0)
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enabled = true;
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mutex_unlock(&edev->lock);
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return enabled;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_is_enabled);
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/**
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* devfreq_event_set_event() - Set event to devfreq-event dev to start.
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* @edev : the devfreq-event device
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*
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* Note that this function set the event to the devfreq-event device to start
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* for getting the event data which could be various event type.
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*/
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int devfreq_event_set_event(struct devfreq_event_dev *edev)
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{
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int ret;
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if (!edev || !edev->desc)
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return -EINVAL;
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if (!edev->desc->ops || !edev->desc->ops->set_event)
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return -EINVAL;
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if (!devfreq_event_is_enabled(edev))
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return -EPERM;
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mutex_lock(&edev->lock);
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ret = edev->desc->ops->set_event(edev);
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mutex_unlock(&edev->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_set_event);
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/**
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* devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev.
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* @edev : the devfreq-event device
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* @edata : the calculated data of devfreq-event device
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*
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* Note that this function get the calculated event data from devfreq-event dev
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* after stoping the progress of whole sequence of devfreq-event dev.
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*/
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int devfreq_event_get_event(struct devfreq_event_dev *edev,
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struct devfreq_event_data *edata)
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{
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int ret;
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if (!edev || !edev->desc)
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return -EINVAL;
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if (!edev->desc->ops || !edev->desc->ops->get_event)
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return -EINVAL;
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if (!devfreq_event_is_enabled(edev))
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return -EINVAL;
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edata->total_count = edata->load_count = 0;
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mutex_lock(&edev->lock);
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ret = edev->desc->ops->get_event(edev, edata);
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if (ret < 0)
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edata->total_count = edata->load_count = 0;
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mutex_unlock(&edev->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_get_event);
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/**
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* devfreq_event_reset_event() - Reset all opeations of devfreq-event dev.
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* @edev : the devfreq-event device
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*
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* Note that this function stop all operations of devfreq-event dev and reset
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* the current event data to make the devfreq-event device into initial state.
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*/
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int devfreq_event_reset_event(struct devfreq_event_dev *edev)
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{
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int ret = 0;
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if (!edev || !edev->desc)
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return -EINVAL;
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if (!devfreq_event_is_enabled(edev))
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return -EPERM;
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mutex_lock(&edev->lock);
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if (edev->desc->ops && edev->desc->ops->reset)
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ret = edev->desc->ops->reset(edev);
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mutex_unlock(&edev->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_reset_event);
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/**
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* devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from
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* devicetree.
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* @dev : the pointer to the given device
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* @phandle_name: name of property holding a phandle value
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* @index : the index into list of devfreq-event device
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*
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* Note that this function return the pointer of devfreq-event device.
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*/
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struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev,
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const char *phandle_name, int index)
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{
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struct device_node *node;
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struct devfreq_event_dev *edev;
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if (!dev->of_node || !phandle_name)
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return ERR_PTR(-EINVAL);
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node = of_parse_phandle(dev->of_node, phandle_name, index);
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if (!node)
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return ERR_PTR(-ENODEV);
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mutex_lock(&devfreq_event_list_lock);
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list_for_each_entry(edev, &devfreq_event_list, node) {
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if (edev->dev.parent && edev->dev.parent->of_node == node)
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goto out;
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}
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list_for_each_entry(edev, &devfreq_event_list, node) {
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if (of_node_name_eq(node, edev->desc->name))
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goto out;
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}
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edev = NULL;
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out:
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mutex_unlock(&devfreq_event_list_lock);
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if (!edev) {
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of_node_put(node);
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return ERR_PTR(-ENODEV);
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}
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of_node_put(node);
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return edev;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_get_edev_by_phandle);
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/**
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* devfreq_event_get_edev_count() - Get the count of devfreq-event dev
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* @dev : the pointer to the given device
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* @phandle_name: name of property holding a phandle value
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*
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* Note that this function return the count of devfreq-event devices.
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*/
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int devfreq_event_get_edev_count(struct device *dev, const char *phandle_name)
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{
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int count;
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if (!dev->of_node || !phandle_name) {
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dev_err(dev, "device does not have a device node entry\n");
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return -EINVAL;
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}
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count = of_property_count_elems_of_size(dev->of_node, phandle_name,
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sizeof(u32));
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if (count < 0) {
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dev_err(dev,
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"failed to get the count of devfreq-event in %pOF node\n",
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dev->of_node);
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return count;
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}
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return count;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_get_edev_count);
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static void devfreq_event_release_edev(struct device *dev)
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{
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struct devfreq_event_dev *edev = to_devfreq_event(dev);
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kfree(edev);
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}
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/**
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* devfreq_event_add_edev() - Add new devfreq-event device.
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* @dev : the device owning the devfreq-event device being created
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* @desc : the devfreq-event device's descriptor which include essential
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* data for devfreq-event device.
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*
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* Note that this function add new devfreq-event device to devfreq-event class
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* list and register the device of the devfreq-event device.
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*/
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struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
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struct devfreq_event_desc *desc)
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{
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struct devfreq_event_dev *edev;
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static atomic_t event_no = ATOMIC_INIT(-1);
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int ret;
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if (!dev || !desc)
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return ERR_PTR(-EINVAL);
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if (!desc->name || !desc->ops)
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return ERR_PTR(-EINVAL);
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if (!desc->ops->set_event || !desc->ops->get_event)
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return ERR_PTR(-EINVAL);
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edev = kzalloc(sizeof(struct devfreq_event_dev), GFP_KERNEL);
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if (!edev)
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return ERR_PTR(-ENOMEM);
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mutex_init(&edev->lock);
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edev->desc = desc;
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edev->enable_count = 0;
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edev->dev.parent = dev;
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edev->dev.class = devfreq_event_class;
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edev->dev.release = devfreq_event_release_edev;
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dev_set_name(&edev->dev, "event%d", atomic_inc_return(&event_no));
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ret = device_register(&edev->dev);
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if (ret < 0) {
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put_device(&edev->dev);
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return ERR_PTR(ret);
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}
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dev_set_drvdata(&edev->dev, edev);
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INIT_LIST_HEAD(&edev->node);
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mutex_lock(&devfreq_event_list_lock);
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list_add(&edev->node, &devfreq_event_list);
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mutex_unlock(&devfreq_event_list_lock);
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return edev;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_add_edev);
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/**
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* devfreq_event_remove_edev() - Remove the devfreq-event device registered.
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* @edev : the devfreq-event device
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*
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* Note that this function removes the registered devfreq-event device.
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*/
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int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
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{
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if (!edev)
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return -EINVAL;
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WARN_ON(edev->enable_count);
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mutex_lock(&devfreq_event_list_lock);
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list_del(&edev->node);
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mutex_unlock(&devfreq_event_list_lock);
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device_unregister(&edev->dev);
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return 0;
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}
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EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
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static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
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{
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struct devfreq_event_dev **r = res;
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if (WARN_ON(!r || !*r))
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return 0;
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return *r == data;
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}
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static void devm_devfreq_event_release(struct device *dev, void *res)
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{
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devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
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}
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/**
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* devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
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* @dev : the device owning the devfreq-event device being created
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* @desc : the devfreq-event device's descriptor which include essential
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* data for devfreq-event device.
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*
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* Note that this function manages automatically the memory of devfreq-event
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* device using device resource management and simplify the free operation
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* for memory of devfreq-event device.
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*/
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struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
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struct devfreq_event_desc *desc)
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{
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struct devfreq_event_dev **ptr, *edev;
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ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr),
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GFP_KERNEL);
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if (!ptr)
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return ERR_PTR(-ENOMEM);
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edev = devfreq_event_add_edev(dev, desc);
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if (IS_ERR(edev)) {
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devres_free(ptr);
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return ERR_PTR(-ENOMEM);
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}
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*ptr = edev;
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devres_add(dev, ptr);
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return edev;
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}
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EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
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/**
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* devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
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* @dev : the device owning the devfreq-event device being created
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* @edev : the devfreq-event device
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*
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* Note that this function manages automatically the memory of devfreq-event
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* device using device resource management.
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*/
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void devm_devfreq_event_remove_edev(struct device *dev,
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struct devfreq_event_dev *edev)
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{
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WARN_ON(devres_release(dev, devm_devfreq_event_release,
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devm_devfreq_event_match, edev));
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}
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EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
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/*
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* Device attributes for devfreq-event class.
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*/
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static ssize_t name_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct devfreq_event_dev *edev = to_devfreq_event(dev);
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if (!edev || !edev->desc)
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return -EINVAL;
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return sprintf(buf, "%s\n", edev->desc->name);
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}
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static DEVICE_ATTR_RO(name);
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static ssize_t enable_count_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct devfreq_event_dev *edev = to_devfreq_event(dev);
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if (!edev || !edev->desc)
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return -EINVAL;
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return sprintf(buf, "%d\n", edev->enable_count);
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}
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static DEVICE_ATTR_RO(enable_count);
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static struct attribute *devfreq_event_attrs[] = {
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&dev_attr_name.attr,
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&dev_attr_enable_count.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(devfreq_event);
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static int __init devfreq_event_init(void)
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{
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devfreq_event_class = class_create(THIS_MODULE, "devfreq-event");
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if (IS_ERR(devfreq_event_class)) {
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pr_err("%s: couldn't create class\n", __FILE__);
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return PTR_ERR(devfreq_event_class);
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}
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devfreq_event_class->dev_groups = devfreq_event_groups;
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return 0;
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}
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subsys_initcall(devfreq_event_init);
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