1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/common.c - Common device power management code.
16 #include "power.h"
19  * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
22  * If power.subsys_data is NULL, point it to a new object, otherwise increment
32 		return -ENOMEM;  in dev_pm_get_subsys_data()
34 	spin_lock_irq(&dev->power.lock);  in dev_pm_get_subsys_data()
36 	if (dev->power.subsys_data) {  in dev_pm_get_subsys_data()
37 		dev->power.subsys_data->refcount++;  in dev_pm_get_subsys_data()
39 		spin_lock_init(&psd->lock);  in dev_pm_get_subsys_data()
40 		psd->refcount = 1;  in dev_pm_get_subsys_data()
41 		dev->power.subsys_data = psd;  in dev_pm_get_subsys_data()
46 	spin_unlock_irq(&dev->power.lock);  in dev_pm_get_subsys_data()
56  * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
59  * If the reference counter of power.subsys_data is zero after dropping the
60  * reference, power.subsys_data is removed.
66 	spin_lock_irq(&dev->power.lock);  in dev_pm_put_subsys_data()
72 	if (--psd->refcount == 0)  in dev_pm_put_subsys_data()
73 		dev->power.subsys_data = NULL;  in dev_pm_put_subsys_data()
78 	spin_unlock_irq(&dev->power.lock);  in dev_pm_put_subsys_data()
84  * dev_pm_domain_attach - Attach a device to its PM domain.
86  * @power_on: Used to indicate whether we should power on the device.
88  * The @dev may only be attached to a single PM domain. By iterating through
89  * the available alternatives we try to find a valid PM domain for the device.
90  * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
95  * power management through PM domains.
97  * Callers must ensure proper synchronization of this function with power
100  * Returns 0 on successfully attached PM domain, or when it is found that the
101  * device doesn't need a PM domain, else a negative error code.
107 	if (dev->pm_domain)  in dev_pm_domain_attach()
119  * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
120  * @dev: The device used to lookup the PM domain.
121  * @index: The index of the PM domain.
123  * As @dev may only be attached to a single PM domain, the backend PM domain
125  * the ->detach() callback in the struct dev_pm_domain are assigned by the
130  * in case its device requires power management through multiple PM domains. The
131  * driver may benefit from using the received device, to configure device-links
132  * towards its original device. Depending on the use-case and if needed, the
134  * the power to the PM domains independently from each other.
136  * Callers must ensure proper synchronization of this function with power
140  * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR().
147 	if (dev->pm_domain)  in dev_pm_domain_attach_by_id()
148 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_id()
155  * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains.
156  * @dev: The device used to lookup the PM domain.
157  * @name: The name of the PM domain.
164 	if (dev->pm_domain)  in dev_pm_domain_attach_by_name()
165 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_name()
172  * dev_pm_domain_attach_list - Associate a device with its PM domains.
175  * @list: An out-parameter with an allocated list of attached PM domains.
183  * Callers must ensure proper synchronization of this function with power
194 	struct device_node *np = dev->of_node;  in dev_pm_domain_attach_list()
200 	u32 pd_flags = data ? data->pd_flags : 0;  in dev_pm_domain_attach_list()
204 	if (dev->pm_domain)  in dev_pm_domain_attach_list()
205 		return -EEXIST;  in dev_pm_domain_attach_list()
211 	if (data && data->pd_names) {  in dev_pm_domain_attach_list()
212 		num_pds = data->num_pd_names;  in dev_pm_domain_attach_list()
215 		num_pds = of_count_phandle_with_args(np, "power-domains",  in dev_pm_domain_attach_list()
216 						     "#power-domain-cells");  in dev_pm_domain_attach_list()
224 		return -ENOMEM;  in dev_pm_domain_attach_list()
226 	size = sizeof(*pds->pd_devs) + sizeof(*pds->pd_links) +  in dev_pm_domain_attach_list()
227 	       sizeof(*pds->opp_tokens);  in dev_pm_domain_attach_list()
228 	pds->pd_devs = kcalloc(num_pds, size, GFP_KERNEL);  in dev_pm_domain_attach_list()
229 	if (!pds->pd_devs) {  in dev_pm_domain_attach_list()
230 		ret = -ENOMEM;  in dev_pm_domain_attach_list()
233 	pds->pd_links = (void *)(pds->pd_devs + num_pds);  in dev_pm_domain_attach_list()
234 	pds->opp_tokens = (void *)(pds->pd_links + num_pds);  in dev_pm_domain_attach_list()
244 							data->pd_names[i]);  in dev_pm_domain_attach_list()
246 			ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV;  in dev_pm_domain_attach_list()
260 			pds->opp_tokens[i] = ret;  in dev_pm_domain_attach_list()
268 				ret = -ENODEV;  in dev_pm_domain_attach_list()
272 			pds->pd_links[i] = link;  in dev_pm_domain_attach_list()
275 		pds->pd_devs[i] = pd_dev;  in dev_pm_domain_attach_list()
278 	pds->num_pds = num_pds;  in dev_pm_domain_attach_list()
283 	dev_pm_opp_clear_config(pds->opp_tokens[i]);  in dev_pm_domain_attach_list()
286 	while (--i >= 0) {  in dev_pm_domain_attach_list()
287 		dev_pm_opp_clear_config(pds->opp_tokens[i]);  in dev_pm_domain_attach_list()
288 		if (pds->pd_links[i])  in dev_pm_domain_attach_list()
289 			device_link_del(pds->pd_links[i]);  in dev_pm_domain_attach_list()
290 		dev_pm_domain_detach(pds->pd_devs[i], true);  in dev_pm_domain_attach_list()
292 	kfree(pds->pd_devs);  in dev_pm_domain_attach_list()
300  * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
315  * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
318  * @list: An out-parameter with an allocated list of attached PM domains.
345  * dev_pm_domain_detach - Detach a device from its PM domain.
347  * @power_off: Used to indicate whether we should power off the device.
351  * detaches @dev from its PM domain.  Typically it should be invoked during the
354  * Callers must ensure proper synchronization of this function with power
359 	if (dev->pm_domain && dev->pm_domain->detach)  in dev_pm_domain_detach()
360 		dev->pm_domain->detach(dev, power_off);  in dev_pm_domain_detach()
365  * dev_pm_domain_detach_list - Detach a list of PM domains.
371  * Callers must ensure proper synchronization of this function with power
381 	for (i = 0; i < list->num_pds; i++) {  in dev_pm_domain_detach_list()
382 		dev_pm_opp_clear_config(list->opp_tokens[i]);  in dev_pm_domain_detach_list()
383 		if (list->pd_links[i])  in dev_pm_domain_detach_list()
384 			device_link_del(list->pd_links[i]);  in dev_pm_domain_detach_list()
385 		dev_pm_domain_detach(list->pd_devs[i], true);  in dev_pm_domain_detach_list()
388 	kfree(list->pd_devs);  in dev_pm_domain_detach_list()
394  * dev_pm_domain_start - Start the device through its PM domain.
398  * when it needs to start its device from the PM domain's perspective. Note
399  * that, it's assumed that the PM domain is already powered on when this
406 	if (dev->pm_domain && dev->pm_domain->start)  in dev_pm_domain_start()
407 		return dev->pm_domain->start(dev);  in dev_pm_domain_start()
414  * dev_pm_domain_set - Set PM domain of a device.
415  * @dev: Device whose PM domain is to be set.
416  * @pd: PM domain to be set, or NULL.
418  * Sets the PM domain the device belongs to. The PM domain of a device needs
425 	if (dev->pm_domain == pd)  in dev_pm_domain_set()
430 	dev->pm_domain = pd;  in dev_pm_domain_set()
436  * dev_pm_domain_set_performance_state - Request a new performance state.
441  * requested for a device that is attached to a PM domain. Note that, the
449 	if (dev->pm_domain && dev->pm_domain->set_performance_state)  in dev_pm_domain_set_performance_state()
450 		return dev->pm_domain->set_performance_state(dev, state);  in dev_pm_domain_set_performance_state()