1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/common.c - Common device power management code.
19  * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
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.
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.
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.
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()
114 	if (dev->pm_domain)  in dev_pm_domain_attach()
115 		dev->power.detach_power_off = !!(flags & PD_FLAG_DETACH_POWER_OFF);  in dev_pm_domain_attach()
122  * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
123  * @dev: The device used to lookup the PM domain.
124  * @index: The index of the PM domain.
126  * As @dev may only be attached to a single PM domain, the backend PM domain
128  * the ->detach() callback in the struct dev_pm_domain are assigned by the
133  * in case its device requires power management through multiple PM domains. The
134  * driver may benefit from using the received device, to configure device-links
135  * towards its original device. Depending on the use-case and if needed, the
137  * the power to the PM domains independently from each other.
142  * Returns the virtual created device when successfully attached to its PM
143  * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR().
150 	if (dev->pm_domain)  in dev_pm_domain_attach_by_id()
151 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_id()
158  * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains.
159  * @dev: The device used to lookup the PM domain.
160  * @name: The name of the PM domain.
167 	if (dev->pm_domain)  in dev_pm_domain_attach_by_name()
168 		return ERR_PTR(-EEXIST);  in dev_pm_domain_attach_by_name()
175  * dev_pm_domain_attach_list - Associate a device with its PM domains.
176  * @dev: The device used to lookup the PM domains for.
177  * @data: The data used for attaching to the PM domains.
178  * @list: An out-parameter with an allocated list of attached PM domains.
180  * This function helps to attach a device to its multiple PM domains. The
182  * names for the PM domains that we should try to attach the device to, but it
184  * the available PM domains.
189  * Returns the number of attached PM domains or a negative error code in case of
190  * a failure. Note that, to detach the list of PM domains, the driver shall call
197 	struct device_node *np = dev->of_node;  in dev_pm_domain_attach_list()
203 	u32 pd_flags = data ? data->pd_flags : 0;  in dev_pm_domain_attach_list()
207 	if (dev->pm_domain)  in dev_pm_domain_attach_list()
208 		return -EEXIST;  in dev_pm_domain_attach_list()
214 	if (data && data->pd_names) {  in dev_pm_domain_attach_list()
215 		num_pds = data->num_pd_names;  in dev_pm_domain_attach_list()
218 		num_pds = of_count_phandle_with_args(np, "power-domains",  in dev_pm_domain_attach_list()
219 						     "#power-domain-cells");  in dev_pm_domain_attach_list()
227 		return -ENOMEM;  in dev_pm_domain_attach_list()
229 	size = sizeof(*pds->pd_devs) + sizeof(*pds->pd_links) +  in dev_pm_domain_attach_list()
230 	       sizeof(*pds->opp_tokens);  in dev_pm_domain_attach_list()
231 	pds->pd_devs = kcalloc(num_pds, size, GFP_KERNEL);  in dev_pm_domain_attach_list()
232 	if (!pds->pd_devs) {  in dev_pm_domain_attach_list()
233 		ret = -ENOMEM;  in dev_pm_domain_attach_list()
236 	pds->pd_links = (void *)(pds->pd_devs + num_pds);  in dev_pm_domain_attach_list()
237 	pds->opp_tokens = (void *)(pds->pd_links + num_pds);  in dev_pm_domain_attach_list()
247 							data->pd_names[i]);  in dev_pm_domain_attach_list()
249 			ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV;  in dev_pm_domain_attach_list()
263 			pds->opp_tokens[i] = ret;  in dev_pm_domain_attach_list()
271 				ret = -ENODEV;  in dev_pm_domain_attach_list()
275 			pds->pd_links[i] = link;  in dev_pm_domain_attach_list()
278 		pds->pd_devs[i] = pd_dev;  in dev_pm_domain_attach_list()
281 	pds->num_pds = num_pds;  in dev_pm_domain_attach_list()
286 	dev_pm_opp_clear_config(pds->opp_tokens[i]);  in dev_pm_domain_attach_list()
289 	while (--i >= 0) {  in dev_pm_domain_attach_list()
290 		dev_pm_opp_clear_config(pds->opp_tokens[i]);  in dev_pm_domain_attach_list()
291 		if (pds->pd_links[i])  in dev_pm_domain_attach_list()
292 			device_link_del(pds->pd_links[i]);  in dev_pm_domain_attach_list()
293 		dev_pm_domain_detach(pds->pd_devs[i], true);  in dev_pm_domain_attach_list()
295 	kfree(pds->pd_devs);  in dev_pm_domain_attach_list()
303  * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
304  * @_list: The list of PM domains to detach.
308  * uses devm_pm_domain_attach_list() to attach the PM domains.
318  * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
319  * @dev: The device used to lookup the PM domains for.
320  * @data: The data used for attaching to the PM domains.
321  * @list: An out-parameter with an allocated list of attached PM domains.
326  * Returns the number of attached PM domains or a negative error code in case of
348  * dev_pm_domain_detach - Detach a device from its PM domain.
354  * detaches @dev from its PM domain.  Typically it should be invoked during the
362 	if (dev->pm_domain && dev->pm_domain->detach)  in dev_pm_domain_detach()
363 		dev->pm_domain->detach(dev, power_off);  in dev_pm_domain_detach()
368  * dev_pm_domain_detach_list - Detach a list of PM domains.
369  * @list: The list of PM domains to detach.
384 	for (i = 0; i < list->num_pds; i++) {  in dev_pm_domain_detach_list()
385 		dev_pm_opp_clear_config(list->opp_tokens[i]);  in dev_pm_domain_detach_list()
386 		if (list->pd_links[i])  in dev_pm_domain_detach_list()
387 			device_link_del(list->pd_links[i]);  in dev_pm_domain_detach_list()
388 		dev_pm_domain_detach(list->pd_devs[i], true);  in dev_pm_domain_detach_list()
391 	kfree(list->pd_devs);  in dev_pm_domain_detach_list()
397  * dev_pm_domain_start - Start the device through its PM domain.
401  * when it needs to start its device from the PM domain's perspective. Note
402  * that, it's assumed that the PM domain is already powered on when this
409 	if (dev->pm_domain && dev->pm_domain->start)  in dev_pm_domain_start()
410 		return dev->pm_domain->start(dev);  in dev_pm_domain_start()
417  * dev_pm_domain_set - Set PM domain of a device.
418  * @dev: Device whose PM domain is to be set.
419  * @pd: PM domain to be set, or NULL.
421  * Sets the PM domain the device belongs to. The PM domain of a device needs
428 	if (dev->pm_domain == pd)  in dev_pm_domain_set()
432 	     "PM domains can only be changed for unbound devices\n");  in dev_pm_domain_set()
433 	dev->pm_domain = pd;  in dev_pm_domain_set()
439  * dev_pm_domain_set_performance_state - Request a new performance state.
444  * requested for a device that is attached to a PM domain. Note that, the
445  * support for performance scaling for PM domains is optional.
452 	if (dev->pm_domain && dev->pm_domain->set_performance_state)  in dev_pm_domain_set_performance_state()
453 		return dev->pm_domain->set_performance_state(dev, state);  in dev_pm_domain_set_performance_state()