diff options
Diffstat (limited to 'drivers/devfreq/devfreq-event.c')
| -rw-r--r-- | drivers/devfreq/devfreq-event.c | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c new file mode 100644 index 000000000000..f304a0289eda --- /dev/null +++ b/drivers/devfreq/devfreq-event.c @@ -0,0 +1,494 @@ +/* + * 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"); |