1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/common.c - Common device power management code.
15 #include "power.h"
18  * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
21  * If power.subsys_data is NULL, point it to a new object, otherwise increment
31 		return -ENOMEM;  in dev_pm_get_subsys_data()
33 	spin_lock_irq(&dev->power.lock);  in dev_pm_get_subsys_data()
35 	if (dev->power.subsys_data) {  in dev_pm_get_subsys_data()
36 		dev->power.subsys_data->refcount++;  in dev_pm_get_subsys_data()
38 		spin_lock_init(&psd->lock);  in dev_pm_get_subsys_data()
39 		psd->refcount = 1;  in dev_pm_get_subsys_data()
40 		dev->power.subsys_data = psd;  in dev_pm_get_subsys_data()
45 	spin_unlock_irq(&dev->power.lock);  in dev_pm_get_subsys_data()
55  * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
58  * If the reference counter of power.subsys_data is zero after dropping the
59  * reference, power.subsys_data is removed.
65 	spin_lock_irq(&dev->power.lock);  in dev_pm_put_subsys_data()
71 	if (--psd->refcount == 0)  in dev_pm_put_subsys_data()
72 		dev->power.subsys_data = NULL;  in dev_pm_put_subsys_data()
77 	spin_unlock_irq(&dev->power.lock);  in dev_pm_put_subsys_data()
83  * dev_pm_domain_attach - Attach a device to its PM domain.
85  * @power_on: Used to indicate whether we should power on the device.
89  * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
94  * power management through PM domains.
96  * Callers must ensure proper synchronization of this function with power
97  * management callbacks.
106 	if (dev->pm_domain)  in dev_pm_domain_attach()
118  * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
124  * the ->detach() callback in the struct dev_pm_domain are assigned by the
129  * in case its device requires power management through multiple PM domains. The
130  * driver may benefit from using the received device, to configure device-links
131  * towards its original device. Depending on the use-case and if needed, the
133  * the power to the PM domains independently from each other.
135  * Callers must ensure proper synchronization of this function with power
136  * management callbacks.
146 	if (dev->pm_domain)  in dev_pm_domain_attach_by_id()
147 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_id()
154  * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains.
163 	if (dev->pm_domain)  in dev_pm_domain_attach_by_name()
164 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_name()
171  * dev_pm_domain_attach_list - Associate a device with its PM domains.
174  * @list: An out-parameter with an allocated list of attached PM domains.
182  * Callers must ensure proper synchronization of this function with power
183  * management callbacks.
193 	struct device_node *np = dev->of_node;  in dev_pm_domain_attach_list()
199 	u32 pd_flags = data ? data->pd_flags : 0;  in dev_pm_domain_attach_list()
203 	if (dev->pm_domain)  in dev_pm_domain_attach_list()
204 		return -EEXIST;  in dev_pm_domain_attach_list()
210 	if (data && data->pd_names) {  in dev_pm_domain_attach_list()
211 		num_pds = data->num_pd_names;  in dev_pm_domain_attach_list()
214 		num_pds = of_count_phandle_with_args(np, "power-domains",  in dev_pm_domain_attach_list()
215 						     "#power-domain-cells");  in dev_pm_domain_attach_list()
223 		return -ENOMEM;  in dev_pm_domain_attach_list()
225 	size = sizeof(*pds->pd_devs) + sizeof(*pds->pd_links);  in dev_pm_domain_attach_list()
226 	pds->pd_devs = kcalloc(num_pds, size, GFP_KERNEL);  in dev_pm_domain_attach_list()
227 	if (!pds->pd_devs) {  in dev_pm_domain_attach_list()
228 		ret = -ENOMEM;  in dev_pm_domain_attach_list()
231 	pds->pd_links = (void *)(pds->pd_devs + num_pds);  in dev_pm_domain_attach_list()
241 							data->pd_names[i]);  in dev_pm_domain_attach_list()
243 			ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV;  in dev_pm_domain_attach_list()
252 				ret = -ENODEV;  in dev_pm_domain_attach_list()
256 			pds->pd_links[i] = link;  in dev_pm_domain_attach_list()
259 		pds->pd_devs[i] = pd_dev;  in dev_pm_domain_attach_list()
262 	pds->num_pds = num_pds;  in dev_pm_domain_attach_list()
269 	while (--i >= 0) {  in dev_pm_domain_attach_list()
270 		if (pds->pd_links[i])  in dev_pm_domain_attach_list()
271 			device_link_del(pds->pd_links[i]);  in dev_pm_domain_attach_list()
272 		dev_pm_domain_detach(pds->pd_devs[i], true);  in dev_pm_domain_attach_list()
274 	kfree(pds->pd_devs);  in dev_pm_domain_attach_list()
282  * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
297  * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
300  * @list: An out-parameter with an allocated list of attached PM domains.
327  * dev_pm_domain_detach - Detach a device from its PM domain.
329  * @power_off: Used to indicate whether we should power off the device.
336  * Callers must ensure proper synchronization of this function with power
337  * management callbacks.
341 	if (dev->pm_domain && dev->pm_domain->detach)  in dev_pm_domain_detach()
342 		dev->pm_domain->detach(dev, power_off);  in dev_pm_domain_detach()
347  * dev_pm_domain_detach_list - Detach a list of PM domains.
353  * Callers must ensure proper synchronization of this function with power
354  * management callbacks.
363 	for (i = 0; i < list->num_pds; i++) {  in dev_pm_domain_detach_list()
364 		if (list->pd_links[i])  in dev_pm_domain_detach_list()
365 			device_link_del(list->pd_links[i]);  in dev_pm_domain_detach_list()
366 		dev_pm_domain_detach(list->pd_devs[i], true);  in dev_pm_domain_detach_list()
369 	kfree(list->pd_devs);  in dev_pm_domain_detach_list()
375  * dev_pm_domain_start - Start the device through its PM domain.
387 	if (dev->pm_domain && dev->pm_domain->start)  in dev_pm_domain_start()
388 		return dev->pm_domain->start(dev);  in dev_pm_domain_start()
395  * dev_pm_domain_set - Set PM domain of a device.
406 	if (dev->pm_domain == pd)  in dev_pm_domain_set()
411 	dev->pm_domain = pd;  in dev_pm_domain_set()
417  * dev_pm_domain_set_performance_state - Request a new performance state.
430 	if (dev->pm_domain && dev->pm_domain->set_performance_state)  in dev_pm_domain_set_performance_state()
431 		return dev->pm_domain->set_performance_state(dev, state);  in dev_pm_domain_set_performance_state()