1 // SPDX-License-Identifier: GPL-2.0-only
3  * devfreq-event: a framework to provide raw data and events of devfreq devices
8  * This driver is based on drivers/devfreq/devfreq.c.
11 #include <linux/devfreq-event.h>
22 /* The list of all devfreq event list */
29  * devfreq_event_enable_edev() - Enable the devfreq-event dev and increase
30  *				 the enable_count of devfreq-event dev.
31  * @edev	: the devfreq-event device
34  * devfreq-event device. The devfreq-event device should be enabled before
35  * using it by devfreq device.
41 	if (!edev || !edev->desc)  in devfreq_event_enable_edev()
42 		return -EINVAL;  in devfreq_event_enable_edev()
44 	mutex_lock(&edev->lock);  in devfreq_event_enable_edev()
45 	if (edev->desc->ops && edev->desc->ops->enable  in devfreq_event_enable_edev()
46 			&& edev->enable_count == 0) {  in devfreq_event_enable_edev()
47 		ret = edev->desc->ops->enable(edev);  in devfreq_event_enable_edev()
51 	edev->enable_count++;  in devfreq_event_enable_edev()
53 	mutex_unlock(&edev->lock);  in devfreq_event_enable_edev()
60  * devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease
61  *				  the enable_count of the devfreq-event dev.
62  * @edev	: the devfreq-event device
65  * devfreq-event device. After the devfreq-event device is disabled,
66  * devfreq device can't use the devfreq-event device for get/set/reset
73 	if (!edev || !edev->desc)  in devfreq_event_disable_edev()
74 		return -EINVAL;  in devfreq_event_disable_edev()
76 	mutex_lock(&edev->lock);  in devfreq_event_disable_edev()
77 	if (edev->enable_count <= 0) {  in devfreq_event_disable_edev()
78 		dev_warn(&edev->dev, "unbalanced enable_count\n");  in devfreq_event_disable_edev()
79 		ret = -EIO;  in devfreq_event_disable_edev()
83 	if (edev->desc->ops && edev->desc->ops->disable  in devfreq_event_disable_edev()
84 			&& edev->enable_count == 1) {  in devfreq_event_disable_edev()
85 		ret = edev->desc->ops->disable(edev);  in devfreq_event_disable_edev()
89 	edev->enable_count--;  in devfreq_event_disable_edev()
91 	mutex_unlock(&edev->lock);  in devfreq_event_disable_edev()
98  * devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or
100  * @edev	: the devfreq-event device
102  * Note that this function check whether devfreq-event dev is enabled or not.
103  * If return true, the devfreq-event dev is enabeld. If return false, the
104  * devfreq-event dev is disabled.
110 	if (!edev || !edev->desc)  in devfreq_event_is_enabled()
113 	mutex_lock(&edev->lock);  in devfreq_event_is_enabled()
115 	if (edev->enable_count > 0)  in devfreq_event_is_enabled()
118 	mutex_unlock(&edev->lock);  in devfreq_event_is_enabled()
125  * devfreq_event_set_event() - Set event to devfreq-event dev to start.
126  * @edev	: the devfreq-event device
128  * Note that this function set the event to the devfreq-event device to start
135 	if (!edev || !edev->desc)  in devfreq_event_set_event()
136 		return -EINVAL;  in devfreq_event_set_event()
138 	if (!edev->desc->ops || !edev->desc->ops->set_event)  in devfreq_event_set_event()
139 		return -EINVAL;  in devfreq_event_set_event()
142 		return -EPERM;  in devfreq_event_set_event()
144 	mutex_lock(&edev->lock);  in devfreq_event_set_event()
145 	ret = edev->desc->ops->set_event(edev);  in devfreq_event_set_event()
146 	mutex_unlock(&edev->lock);  in devfreq_event_set_event()
153  * devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev.
154  * @edev	: the devfreq-event device
155  * @edata	: the calculated data of devfreq-event device
157  * Note that this function get the calculated event data from devfreq-event dev
158  * after stoping the progress of whole sequence of devfreq-event dev.
165 	if (!edev || !edev->desc)  in devfreq_event_get_event()
166 		return -EINVAL;  in devfreq_event_get_event()
168 	if (!edev->desc->ops || !edev->desc->ops->get_event)  in devfreq_event_get_event()
169 		return -EINVAL;  in devfreq_event_get_event()
172 		return -EINVAL;  in devfreq_event_get_event()
174 	edata->total_count = edata->load_count = 0;  in devfreq_event_get_event()
176 	mutex_lock(&edev->lock);  in devfreq_event_get_event()
177 	ret = edev->desc->ops->get_event(edev, edata);  in devfreq_event_get_event()
179 		edata->total_count = edata->load_count = 0;  in devfreq_event_get_event()
180 	mutex_unlock(&edev->lock);  in devfreq_event_get_event()
187  * devfreq_event_reset_event() - Reset all opeations of devfreq-event dev.
188  * @edev	: the devfreq-event device
190  * Note that this function stop all operations of devfreq-event dev and reset
191  * the current event data to make the devfreq-event device into initial state.
197 	if (!edev || !edev->desc)  in devfreq_event_reset_event()
198 		return -EINVAL;  in devfreq_event_reset_event()
201 		return -EPERM;  in devfreq_event_reset_event()
203 	mutex_lock(&edev->lock);  in devfreq_event_reset_event()
204 	if (edev->desc->ops && edev->desc->ops->reset)  in devfreq_event_reset_event()
205 		ret = edev->desc->ops->reset(edev);  in devfreq_event_reset_event()
206 	mutex_unlock(&edev->lock);  in devfreq_event_reset_event()
213  * devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from
217  * @index	: the index into list of devfreq-event device
219  * Note that this function return the pointer of devfreq-event device.
227 	if (!dev->of_node || !phandle_name)  in devfreq_event_get_edev_by_phandle()
228 		return ERR_PTR(-EINVAL);  in devfreq_event_get_edev_by_phandle()
230 	node = of_parse_phandle(dev->of_node, phandle_name, index);  in devfreq_event_get_edev_by_phandle()
232 		return ERR_PTR(-ENODEV);  in devfreq_event_get_edev_by_phandle()
236 		if (edev->dev.parent && device_match_of_node(edev->dev.parent, node))  in devfreq_event_get_edev_by_phandle()
241 		if (of_node_name_eq(node, edev->desc->name))  in devfreq_event_get_edev_by_phandle()
250 		return ERR_PTR(-ENODEV);  in devfreq_event_get_edev_by_phandle()
260  * devfreq_event_get_edev_count() - Get the count of devfreq-event dev
264  * Note that this function return the count of devfreq-event devices.
270 	if (!dev->of_node || !phandle_name) {  in devfreq_event_get_edev_count()
272 		return -EINVAL;  in devfreq_event_get_edev_count()
275 	count = of_property_count_elems_of_size(dev->of_node, phandle_name,  in devfreq_event_get_edev_count()
279 			"failed to get the count of devfreq-event in %pOF node\n",  in devfreq_event_get_edev_count()
280 			dev->of_node);  in devfreq_event_get_edev_count()
296  * devfreq_event_add_edev() - Add new devfreq-event device.
297  * @dev		: the device owning the devfreq-event device being created
298  * @desc	: the devfreq-event device's descriptor which include essential
299  *		  data for devfreq-event device.
301  * Note that this function add new devfreq-event device to devfreq-event class
302  * list and register the device of the devfreq-event device.
308 	static atomic_t event_no = ATOMIC_INIT(-1);  in devfreq_event_add_edev()
312 		return ERR_PTR(-EINVAL);  in devfreq_event_add_edev()
314 	if (!desc->name || !desc->ops)  in devfreq_event_add_edev()
315 		return ERR_PTR(-EINVAL);  in devfreq_event_add_edev()
317 	if (!desc->ops->set_event || !desc->ops->get_event)  in devfreq_event_add_edev()
318 		return ERR_PTR(-EINVAL);  in devfreq_event_add_edev()
322 		return ERR_PTR(-ENOMEM);  in devfreq_event_add_edev()
324 	mutex_init(&edev->lock);  in devfreq_event_add_edev()
325 	edev->desc = desc;  in devfreq_event_add_edev()
326 	edev->enable_count = 0;  in devfreq_event_add_edev()
327 	edev->dev.parent = dev;  in devfreq_event_add_edev()
328 	edev->dev.class = devfreq_event_class;  in devfreq_event_add_edev()
329 	edev->dev.release = devfreq_event_release_edev;  in devfreq_event_add_edev()
331 	dev_set_name(&edev->dev, "event%d", atomic_inc_return(&event_no));  in devfreq_event_add_edev()
332 	ret = device_register(&edev->dev);  in devfreq_event_add_edev()
334 		put_device(&edev->dev);  in devfreq_event_add_edev()
337 	dev_set_drvdata(&edev->dev, edev);  in devfreq_event_add_edev()
339 	INIT_LIST_HEAD(&edev->node);  in devfreq_event_add_edev()
342 	list_add(&edev->node, &devfreq_event_list);  in devfreq_event_add_edev()
350  * devfreq_event_remove_edev() - Remove the devfreq-event device registered.
351  * @edev	: the devfreq-event device
353  * Note that this function removes the registered devfreq-event device.
358 		return -EINVAL;  in devfreq_event_remove_edev()
360 	WARN_ON(edev->enable_count);  in devfreq_event_remove_edev()
363 	list_del(&edev->node);  in devfreq_event_remove_edev()
366 	device_unregister(&edev->dev);  in devfreq_event_remove_edev()
388  * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
389  * @dev		: the device owning the devfreq-event device being created
390  * @desc	: the devfreq-event device's descriptor which include essential
391  *		  data for devfreq-event device.
393  * Note that this function manages automatically the memory of devfreq-event
395  * for memory of devfreq-event device.
405 		return ERR_PTR(-ENOMEM);  in devm_devfreq_event_add_edev()
410 		return ERR_PTR(-ENOMEM);  in devm_devfreq_event_add_edev()
421  * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
422  * @dev		: the device owning the devfreq-event device being created
423  * @edev	: the devfreq-event device
425  * Note that this function manages automatically the memory of devfreq-event
437  * Device attributes for devfreq-event class.
444 	if (!edev || !edev->desc)  in name_show()
445 		return -EINVAL;  in name_show()
447 	return sprintf(buf, "%s\n", edev->desc->name);  in name_show()
456 	if (!edev || !edev->desc)  in enable_count_show()
457 		return -EINVAL;  in enable_count_show()
459 	return sprintf(buf, "%d\n", edev->enable_count);  in enable_count_show()
472 	devfreq_event_class = class_create("devfreq-event");  in devfreq_event_init()
478 	devfreq_event_class->dev_groups = devfreq_event_groups;  in devfreq_event_init()