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Rafael J. Wysockief27bed2011-08-25 15:34:01 +02001/*
2 * drivers/base/power/common.c - Common device power management code.
3 *
4 * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
5 *
6 * This file is released under the GPLv2.
7 */
8
Rafael J. Wysockief27bed2011-08-25 15:34:01 +02009#include <linux/kernel.h>
Paul Gortmaker51990e82012-01-22 11:23:42 -050010#include <linux/device.h>
Paul Gortmakeraaf19542011-09-28 18:23:03 -040011#include <linux/export.h>
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020012#include <linux/slab.h>
Rafael J. Wysockib5e8d262011-08-25 15:34:19 +020013#include <linux/pm_clock.h>
Ulf Hansson46420dd2014-09-19 20:27:37 +020014#include <linux/acpi.h>
15#include <linux/pm_domain.h>
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020016
Tomeu Vizosoaa8e54b52016-01-07 16:46:14 +010017#include "power.h"
18
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020019/**
20 * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
21 * @dev: Device to handle.
22 *
23 * If power.subsys_data is NULL, point it to a new object, otherwise increment
Ulf Hansson766bb532015-01-29 18:39:04 +010024 * its reference counter. Return 0 if new object has been created or refcount
25 * increased, otherwise negative error code.
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020026 */
27int dev_pm_get_subsys_data(struct device *dev)
28{
29 struct pm_subsys_data *psd;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020030
31 psd = kzalloc(sizeof(*psd), GFP_KERNEL);
32 if (!psd)
33 return -ENOMEM;
34
35 spin_lock_irq(&dev->power.lock);
36
37 if (dev->power.subsys_data) {
38 dev->power.subsys_data->refcount++;
39 } else {
40 spin_lock_init(&psd->lock);
41 psd->refcount = 1;
42 dev->power.subsys_data = psd;
43 pm_clk_init(dev);
44 psd = NULL;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020045 }
46
47 spin_unlock_irq(&dev->power.lock);
48
49 /* kfree() verifies that its argument is nonzero. */
50 kfree(psd);
51
Rafael J. Wysocki77254952012-08-07 13:50:14 +020052 return 0;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020053}
54EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
55
56/**
57 * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
58 * @dev: Device to handle.
59 *
60 * If the reference counter of power.subsys_data is zero after dropping the
Ulf Hansson1e95e3b2015-01-29 18:39:05 +010061 * reference, power.subsys_data is removed.
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020062 */
Ulf Hansson1e95e3b2015-01-29 18:39:05 +010063void dev_pm_put_subsys_data(struct device *dev)
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020064{
65 struct pm_subsys_data *psd;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020066
67 spin_lock_irq(&dev->power.lock);
68
69 psd = dev_to_psd(dev);
Shuah Khand5e1670a2013-05-08 01:14:32 +020070 if (!psd)
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020071 goto out;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020072
Ulf Hansson1e95e3b2015-01-29 18:39:05 +010073 if (--psd->refcount == 0)
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020074 dev->power.subsys_data = NULL;
Ulf Hansson1e95e3b2015-01-29 18:39:05 +010075 else
Shuah Khand5e1670a2013-05-08 01:14:32 +020076 psd = NULL;
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020077
78 out:
79 spin_unlock_irq(&dev->power.lock);
Shuah Khand5e1670a2013-05-08 01:14:32 +020080 kfree(psd);
Rafael J. Wysockief27bed2011-08-25 15:34:01 +020081}
82EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
Ulf Hansson46420dd2014-09-19 20:27:37 +020083
84/**
85 * dev_pm_domain_attach - Attach a device to its PM domain.
86 * @dev: Device to attach.
87 * @power_on: Used to indicate whether we should power on the device.
88 *
89 * The @dev may only be attached to a single PM domain. By iterating through
90 * the available alternatives we try to find a valid PM domain for the device.
91 * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
92 * should be assigned by the corresponding attach function.
93 *
94 * This function should typically be invoked from subsystem level code during
95 * the probe phase. Especially for those that holds devices which requires
96 * power management through PM domains.
97 *
98 * Callers must ensure proper synchronization of this function with power
99 * management callbacks.
100 *
Geert Uytterhoeven49072f92018-05-15 15:21:43 +0200101 * Returns 0 on successfully attached PM domain, or when it is found that the
102 * device doesn't need a PM domain, else a negative error code.
Ulf Hansson46420dd2014-09-19 20:27:37 +0200103 */
104int dev_pm_domain_attach(struct device *dev, bool power_on)
105{
106 int ret;
107
Ulf Hansson4f688742018-04-26 10:53:03 +0200108 if (dev->pm_domain)
Ulf Hansson94ef9b82018-05-14 16:52:37 +0200109 return 0;
Ulf Hansson4f688742018-04-26 10:53:03 +0200110
Ulf Hansson46420dd2014-09-19 20:27:37 +0200111 ret = acpi_dev_pm_attach(dev, power_on);
Ulf Hansson919b7302018-05-09 12:17:52 +0200112 if (!ret)
Ulf Hansson46420dd2014-09-19 20:27:37 +0200113 ret = genpd_dev_pm_attach(dev);
114
Ulf Hansson919b7302018-05-09 12:17:52 +0200115 return ret < 0 ? ret : 0;
Ulf Hansson46420dd2014-09-19 20:27:37 +0200116}
117EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
118
119/**
Ulf Hansson82e12d92018-05-31 12:59:59 +0200120 * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
121 * @dev: The device used to lookup the PM domain.
122 * @index: The index of the PM domain.
123 *
124 * As @dev may only be attached to a single PM domain, the backend PM domain
125 * provider creates a virtual device to attach instead. If attachment succeeds,
126 * the ->detach() callback in the struct dev_pm_domain are assigned by the
127 * corresponding backend attach function, as to deal with detaching of the
128 * created virtual device.
129 *
130 * This function should typically be invoked by a driver during the probe phase,
131 * in case its device requires power management through multiple PM domains. The
132 * driver may benefit from using the received device, to configure device-links
133 * towards its original device. Depending on the use-case and if needed, the
134 * links may be dynamically changed by the driver, which allows it to control
135 * the power to the PM domains independently from each other.
136 *
137 * Callers must ensure proper synchronization of this function with power
138 * management callbacks.
139 *
140 * Returns the virtual created device when successfully attached to its PM
141 * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR().
142 * Note that, to detach the returned virtual device, the driver shall call
143 * dev_pm_domain_detach() on it, typically during the remove phase.
144 */
145struct device *dev_pm_domain_attach_by_id(struct device *dev,
146 unsigned int index)
147{
148 if (dev->pm_domain)
149 return ERR_PTR(-EEXIST);
150
151 return genpd_dev_pm_attach_by_id(dev, index);
152}
153EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_id);
154
155/**
Ulf Hansson46420dd2014-09-19 20:27:37 +0200156 * dev_pm_domain_detach - Detach a device from its PM domain.
Manuel Pégourié-Gonnard42957332015-12-29 11:03:21 +0100157 * @dev: Device to detach.
Ulf Hansson46420dd2014-09-19 20:27:37 +0200158 * @power_off: Used to indicate whether we should power off the device.
159 *
Ulf Hansson82e12d92018-05-31 12:59:59 +0200160 * This functions will reverse the actions from dev_pm_domain_attach() and
161 * dev_pm_domain_attach_by_id(), thus it detaches @dev from its PM domain.
162 * Typically it should be invoked during the remove phase, either from
163 * subsystem level code or from drivers.
Ulf Hansson46420dd2014-09-19 20:27:37 +0200164 *
165 * Callers must ensure proper synchronization of this function with power
166 * management callbacks.
167 */
168void dev_pm_domain_detach(struct device *dev, bool power_off)
169{
170 if (dev->pm_domain && dev->pm_domain->detach)
171 dev->pm_domain->detach(dev, power_off);
172}
173EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
Tomeu Vizoso989561d2016-01-07 16:46:13 +0100174
175/**
176 * dev_pm_domain_set - Set PM domain of a device.
177 * @dev: Device whose PM domain is to be set.
178 * @pd: PM domain to be set, or NULL.
179 *
180 * Sets the PM domain the device belongs to. The PM domain of a device needs
181 * to be set before its probe finishes (it's bound to a driver).
182 *
183 * This function must be called with the device lock held.
184 */
185void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
186{
187 if (dev->pm_domain == pd)
188 return;
189
Rafael J. Wysockie79aee42016-01-30 12:54:29 +0100190 WARN(pd && device_is_bound(dev),
Tomeu Vizoso989561d2016-01-07 16:46:13 +0100191 "PM domains can only be changed for unbound devices\n");
192 dev->pm_domain = pd;
Tomeu Vizosoaa8e54b52016-01-07 16:46:14 +0100193 device_pm_check_callbacks(dev);
Tomeu Vizoso989561d2016-01-07 16:46:13 +0100194}
195EXPORT_SYMBOL_GPL(dev_pm_domain_set);