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5de363b6 | 1 | // SPDX-License-Identifier: GPL-2.0 |
ef27bed1 RW |
2 | /* |
3 | * drivers/base/power/common.c - Common device power management code. | |
4 | * | |
5 | * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. | |
ef27bed1 | 6 | */ |
ef27bed1 | 7 | #include <linux/kernel.h> |
51990e82 | 8 | #include <linux/device.h> |
aaf19544 | 9 | #include <linux/export.h> |
ef27bed1 | 10 | #include <linux/slab.h> |
b5e8d269 | 11 | #include <linux/pm_clock.h> |
46420dd7 UH |
12 | #include <linux/acpi.h> |
13 | #include <linux/pm_domain.h> | |
ef27bed1 | 14 | |
aa8e54b5 TV |
15 | #include "power.h" |
16 | ||
ef27bed1 RW |
17 | /** |
18 | * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device. | |
19 | * @dev: Device to handle. | |
20 | * | |
21 | * If power.subsys_data is NULL, point it to a new object, otherwise increment | |
766bb53c UH |
22 | * its reference counter. Return 0 if new object has been created or refcount |
23 | * increased, otherwise negative error code. | |
ef27bed1 RW |
24 | */ |
25 | int dev_pm_get_subsys_data(struct device *dev) | |
26 | { | |
27 | struct pm_subsys_data *psd; | |
ef27bed1 RW |
28 | |
29 | psd = kzalloc(sizeof(*psd), GFP_KERNEL); | |
30 | if (!psd) | |
31 | return -ENOMEM; | |
32 | ||
33 | spin_lock_irq(&dev->power.lock); | |
34 | ||
35 | if (dev->power.subsys_data) { | |
36 | dev->power.subsys_data->refcount++; | |
37 | } else { | |
38 | spin_lock_init(&psd->lock); | |
39 | psd->refcount = 1; | |
40 | dev->power.subsys_data = psd; | |
41 | pm_clk_init(dev); | |
42 | psd = NULL; | |
ef27bed1 RW |
43 | } |
44 | ||
45 | spin_unlock_irq(&dev->power.lock); | |
46 | ||
47 | /* kfree() verifies that its argument is nonzero. */ | |
48 | kfree(psd); | |
49 | ||
77254950 | 50 | return 0; |
ef27bed1 RW |
51 | } |
52 | EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data); | |
53 | ||
54 | /** | |
55 | * dev_pm_put_subsys_data - Drop reference to power.subsys_data. | |
56 | * @dev: Device to handle. | |
57 | * | |
58 | * If the reference counter of power.subsys_data is zero after dropping the | |
1e95e3b2 | 59 | * reference, power.subsys_data is removed. |
ef27bed1 | 60 | */ |
1e95e3b2 | 61 | void dev_pm_put_subsys_data(struct device *dev) |
ef27bed1 RW |
62 | { |
63 | struct pm_subsys_data *psd; | |
ef27bed1 RW |
64 | |
65 | spin_lock_irq(&dev->power.lock); | |
66 | ||
67 | psd = dev_to_psd(dev); | |
d5e1670a | 68 | if (!psd) |
ef27bed1 | 69 | goto out; |
ef27bed1 | 70 | |
1e95e3b2 | 71 | if (--psd->refcount == 0) |
ef27bed1 | 72 | dev->power.subsys_data = NULL; |
1e95e3b2 | 73 | else |
d5e1670a | 74 | psd = NULL; |
ef27bed1 RW |
75 | |
76 | out: | |
77 | spin_unlock_irq(&dev->power.lock); | |
d5e1670a | 78 | kfree(psd); |
ef27bed1 RW |
79 | } |
80 | EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data); | |
46420dd7 UH |
81 | |
82 | /** | |
83 | * dev_pm_domain_attach - Attach a device to its PM domain. | |
84 | * @dev: Device to attach. | |
85 | * @power_on: Used to indicate whether we should power on the device. | |
86 | * | |
87 | * The @dev may only be attached to a single PM domain. By iterating through | |
88 | * the available alternatives we try to find a valid PM domain for the device. | |
89 | * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain | |
90 | * should be assigned by the corresponding attach function. | |
91 | * | |
92 | * This function should typically be invoked from subsystem level code during | |
93 | * the probe phase. Especially for those that holds devices which requires | |
94 | * power management through PM domains. | |
95 | * | |
96 | * Callers must ensure proper synchronization of this function with power | |
97 | * management callbacks. | |
98 | * | |
49072f97 GU |
99 | * Returns 0 on successfully attached PM domain, or when it is found that the |
100 | * device doesn't need a PM domain, else a negative error code. | |
46420dd7 UH |
101 | */ |
102 | int dev_pm_domain_attach(struct device *dev, bool power_on) | |
103 | { | |
104 | int ret; | |
105 | ||
4f688748 | 106 | if (dev->pm_domain) |
94ef9b8e | 107 | return 0; |
4f688748 | 108 | |
46420dd7 | 109 | ret = acpi_dev_pm_attach(dev, power_on); |
919b7308 | 110 | if (!ret) |
46420dd7 UH |
111 | ret = genpd_dev_pm_attach(dev); |
112 | ||
919b7308 | 113 | return ret < 0 ? ret : 0; |
46420dd7 UH |
114 | } |
115 | EXPORT_SYMBOL_GPL(dev_pm_domain_attach); | |
116 | ||
82e12d9e UH |
117 | /** |
118 | * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains. | |
119 | * @dev: The device used to lookup the PM domain. | |
120 | * @index: The index of the PM domain. | |
121 | * | |
122 | * As @dev may only be attached to a single PM domain, the backend PM domain | |
123 | * provider creates a virtual device to attach instead. If attachment succeeds, | |
124 | * the ->detach() callback in the struct dev_pm_domain are assigned by the | |
125 | * corresponding backend attach function, as to deal with detaching of the | |
126 | * created virtual device. | |
127 | * | |
128 | * This function should typically be invoked by a driver during the probe phase, | |
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 | |
132 | * links may be dynamically changed by the driver, which allows it to control | |
133 | * the power to the PM domains independently from each other. | |
134 | * | |
135 | * Callers must ensure proper synchronization of this function with power | |
136 | * management callbacks. | |
137 | * | |
138 | * Returns the virtual created device when successfully attached to its PM | |
139 | * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR(). | |
140 | * Note that, to detach the returned virtual device, the driver shall call | |
141 | * dev_pm_domain_detach() on it, typically during the remove phase. | |
142 | */ | |
143 | struct device *dev_pm_domain_attach_by_id(struct device *dev, | |
144 | unsigned int index) | |
145 | { | |
146 | if (dev->pm_domain) | |
147 | return ERR_PTR(-EEXIST); | |
148 | ||
149 | return genpd_dev_pm_attach_by_id(dev, index); | |
150 | } | |
151 | EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_id); | |
152 | ||
27dceb81 UH |
153 | /** |
154 | * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains. | |
155 | * @dev: The device used to lookup the PM domain. | |
156 | * @name: The name of the PM domain. | |
157 | * | |
158 | * For a detailed function description, see dev_pm_domain_attach_by_id(). | |
159 | */ | |
160 | struct device *dev_pm_domain_attach_by_name(struct device *dev, | |
eeb35df0 | 161 | const char *name) |
27dceb81 UH |
162 | { |
163 | if (dev->pm_domain) | |
164 | return ERR_PTR(-EEXIST); | |
165 | ||
166 | return genpd_dev_pm_attach_by_name(dev, name); | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name); | |
169 | ||
46420dd7 UH |
170 | /** |
171 | * dev_pm_domain_detach - Detach a device from its PM domain. | |
4295733e | 172 | * @dev: Device to detach. |
46420dd7 UH |
173 | * @power_off: Used to indicate whether we should power off the device. |
174 | * | |
eefa8618 KK |
175 | * This functions will reverse the actions from dev_pm_domain_attach(), |
176 | * dev_pm_domain_attach_by_id() and dev_pm_domain_attach_by_name(), thus it | |
177 | * detaches @dev from its PM domain. Typically it should be invoked during the | |
178 | * remove phase, either from subsystem level code or from drivers. | |
46420dd7 UH |
179 | * |
180 | * Callers must ensure proper synchronization of this function with power | |
181 | * management callbacks. | |
182 | */ | |
183 | void dev_pm_domain_detach(struct device *dev, bool power_off) | |
184 | { | |
185 | if (dev->pm_domain && dev->pm_domain->detach) | |
186 | dev->pm_domain->detach(dev, power_off); | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(dev_pm_domain_detach); | |
989561de | 189 | |
ca765a8c UH |
190 | /** |
191 | * dev_pm_domain_start - Start the device through its PM domain. | |
192 | * @dev: Device to start. | |
193 | * | |
194 | * This function should typically be called during probe by a subsystem/driver, | |
195 | * when it needs to start its device from the PM domain's perspective. Note | |
196 | * that, it's assumed that the PM domain is already powered on when this | |
197 | * function is called. | |
198 | * | |
199 | * Returns 0 on success and negative error values on failures. | |
200 | */ | |
201 | int dev_pm_domain_start(struct device *dev) | |
202 | { | |
203 | if (dev->pm_domain && dev->pm_domain->start) | |
204 | return dev->pm_domain->start(dev); | |
205 | ||
206 | return 0; | |
207 | } | |
208 | EXPORT_SYMBOL_GPL(dev_pm_domain_start); | |
209 | ||
989561de TV |
210 | /** |
211 | * dev_pm_domain_set - Set PM domain of a device. | |
212 | * @dev: Device whose PM domain is to be set. | |
213 | * @pd: PM domain to be set, or NULL. | |
214 | * | |
215 | * Sets the PM domain the device belongs to. The PM domain of a device needs | |
216 | * to be set before its probe finishes (it's bound to a driver). | |
217 | * | |
218 | * This function must be called with the device lock held. | |
219 | */ | |
220 | void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd) | |
221 | { | |
222 | if (dev->pm_domain == pd) | |
223 | return; | |
224 | ||
e79aee49 | 225 | WARN(pd && device_is_bound(dev), |
989561de TV |
226 | "PM domains can only be changed for unbound devices\n"); |
227 | dev->pm_domain = pd; | |
aa8e54b5 | 228 | device_pm_check_callbacks(dev); |
989561de TV |
229 | } |
230 | EXPORT_SYMBOL_GPL(dev_pm_domain_set); |