base/power/common.c

1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/common.c - Common device power management code.
18  * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
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.
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.
89  * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
94  * power management through PM domains.
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.
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_detach - Detach a device from its PM domain.
185 	if (dev->pm_domain && dev->pm_domain->detach)  in dev_pm_domain_detach()
186 		dev->pm_domain->detach(dev, power_off);  in dev_pm_domain_detach()
191  * dev_pm_domain_start - Start the device through its PM domain.
203 	if (dev->pm_domain && dev->pm_domain->start)  in dev_pm_domain_start()
204 		return dev->pm_domain->start(dev);  in dev_pm_domain_start()
211  * dev_pm_domain_set - Set PM domain of a device.
222 	if (dev->pm_domain == pd)  in dev_pm_domain_set()
226 	     "PM domains can only be changed for unbound devices\n");  in dev_pm_domain_set()
227 	dev->pm_domain = pd;  in dev_pm_domain_set()
233  * dev_pm_domain_set_performance_state - Request a new performance state.
235  * @state: Target performance state for the device.
237  * This function should be called when a new performance state needs to be
239  * support for performance scaling for PM domains is optional.
241  * Returns 0 on success and when performance scaling isn't supported, negative
246 	if (dev->pm_domain && dev->pm_domain->set_performance_state)  in dev_pm_domain_set_performance_state()
247 		return dev->pm_domain->set_performance_state(dev, state);  in dev_pm_domain_set_performance_state()