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1 | /* |
2 | * Generic OPP Interface | |
3 | * | |
4 | * Copyright (C) 2009-2010 Texas Instruments Incorporated. | |
5 | * Nishanth Menon | |
6 | * Romit Dasgupta | |
7 | * Kevin Hilman | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #ifndef __DRIVER_OPP_H__ | |
15 | #define __DRIVER_OPP_H__ | |
16 | ||
17 | #include <linux/device.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/list.h> | |
deaa5146 | 20 | #include <linux/limits.h> |
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21 | #include <linux/pm_opp.h> |
22 | #include <linux/rculist.h> | |
23 | #include <linux/rcupdate.h> | |
24 | ||
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25 | /* Lock to allow exclusive modification to the device and opp lists */ |
26 | extern struct mutex dev_opp_list_lock; | |
27 | ||
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28 | /* |
29 | * Internal data structure organization with the OPP layer library is as | |
30 | * follows: | |
31 | * dev_opp_list (root) | |
32 | * |- device 1 (represents voltage domain 1) | |
33 | * | |- opp 1 (availability, freq, voltage) | |
34 | * | |- opp 2 .. | |
35 | * ... ... | |
36 | * | `- opp n .. | |
37 | * |- device 2 (represents the next voltage domain) | |
38 | * ... | |
39 | * `- device m (represents mth voltage domain) | |
40 | * device 1, 2.. are represented by dev_opp structure while each opp | |
41 | * is represented by the opp structure. | |
42 | */ | |
43 | ||
44 | /** | |
45 | * struct dev_pm_opp - Generic OPP description structure | |
46 | * @node: opp list node. The nodes are maintained throughout the lifetime | |
47 | * of boot. It is expected only an optimal set of OPPs are | |
48 | * added to the library by the SoC framework. | |
49 | * RCU usage: opp list is traversed with RCU locks. node | |
50 | * modification is possible realtime, hence the modifications | |
51 | * are protected by the dev_opp_list_lock for integrity. | |
52 | * IMPORTANT: the opp nodes should be maintained in increasing | |
53 | * order. | |
f59d3ee8 | 54 | * @available: true/false - marks if this OPP as available or not |
dc4e7b1f | 55 | * @dynamic: not-created from static DT entries. |
f59d3ee8 | 56 | * @turbo: true if turbo (boost) OPP |
deaa5146 | 57 | * @suspend: true if suspend OPP |
f59d3ee8 VK |
58 | * @rate: Frequency in hertz |
59 | * @u_volt: Target voltage in microvolts corresponding to this OPP | |
60 | * @u_volt_min: Minimum voltage in microvolts corresponding to this OPP | |
61 | * @u_volt_max: Maximum voltage in microvolts corresponding to this OPP | |
62 | * @u_amp: Maximum current drawn by the device in microamperes | |
63 | * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's | |
64 | * frequency from any other OPP's frequency. | |
65 | * @dev_opp: points back to the device_opp struct this opp belongs to | |
66 | * @rcu_head: RCU callback head used for deferred freeing | |
67 | * @np: OPP's device node. | |
deaa5146 | 68 | * @dentry: debugfs dentry pointer (per opp) |
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69 | * |
70 | * This structure stores the OPP information for a given device. | |
71 | */ | |
72 | struct dev_pm_opp { | |
73 | struct list_head node; | |
74 | ||
75 | bool available; | |
76 | bool dynamic; | |
77 | bool turbo; | |
deaa5146 | 78 | bool suspend; |
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79 | unsigned long rate; |
80 | ||
81 | unsigned long u_volt; | |
82 | unsigned long u_volt_min; | |
83 | unsigned long u_volt_max; | |
84 | unsigned long u_amp; | |
85 | unsigned long clock_latency_ns; | |
86 | ||
87 | struct device_opp *dev_opp; | |
88 | struct rcu_head rcu_head; | |
89 | ||
90 | struct device_node *np; | |
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91 | |
92 | #ifdef CONFIG_DEBUG_FS | |
93 | struct dentry *dentry; | |
94 | #endif | |
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95 | }; |
96 | ||
97 | /** | |
98 | * struct device_list_opp - devices managed by 'struct device_opp' | |
99 | * @node: list node | |
100 | * @dev: device to which the struct object belongs | |
101 | * @rcu_head: RCU callback head used for deferred freeing | |
deaa5146 | 102 | * @dentry: debugfs dentry pointer (per device) |
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103 | * |
104 | * This is an internal data structure maintaining the list of devices that are | |
105 | * managed by 'struct device_opp'. | |
106 | */ | |
107 | struct device_list_opp { | |
108 | struct list_head node; | |
109 | const struct device *dev; | |
110 | struct rcu_head rcu_head; | |
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111 | |
112 | #ifdef CONFIG_DEBUG_FS | |
113 | struct dentry *dentry; | |
114 | #endif | |
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115 | }; |
116 | ||
117 | /** | |
118 | * struct device_opp - Device opp structure | |
119 | * @node: list node - contains the devices with OPPs that | |
120 | * have been registered. Nodes once added are not modified in this | |
121 | * list. | |
122 | * RCU usage: nodes are not modified in the list of device_opp, | |
123 | * however addition is possible and is secured by dev_opp_list_lock | |
124 | * @srcu_head: notifier head to notify the OPP availability changes. | |
125 | * @rcu_head: RCU callback head used for deferred freeing | |
126 | * @dev_list: list of devices that share these OPPs | |
127 | * @opp_list: list of opps | |
128 | * @np: struct device_node pointer for opp's DT node. | |
dc4e7b1f | 129 | * @clock_latency_ns_max: Max clock latency in nanoseconds. |
f59d3ee8 | 130 | * @shared_opp: OPP is shared between multiple devices. |
dc4e7b1f | 131 | * @suspend_opp: Pointer to OPP to be used during device suspend. |
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132 | * @dentry: debugfs dentry pointer of the real device directory (not links). |
133 | * @dentry_name: Name of the real dentry. | |
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134 | * |
135 | * This is an internal data structure maintaining the link to opps attached to | |
136 | * a device. This structure is not meant to be shared to users as it is | |
137 | * meant for book keeping and private to OPP library. | |
138 | * | |
139 | * Because the opp structures can be used from both rcu and srcu readers, we | |
140 | * need to wait for the grace period of both of them before freeing any | |
141 | * resources. And so we have used kfree_rcu() from within call_srcu() handlers. | |
142 | */ | |
143 | struct device_opp { | |
144 | struct list_head node; | |
145 | ||
146 | struct srcu_notifier_head srcu_head; | |
147 | struct rcu_head rcu_head; | |
148 | struct list_head dev_list; | |
149 | struct list_head opp_list; | |
150 | ||
151 | struct device_node *np; | |
152 | unsigned long clock_latency_ns_max; | |
153 | bool shared_opp; | |
154 | struct dev_pm_opp *suspend_opp; | |
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155 | |
156 | #ifdef CONFIG_DEBUG_FS | |
157 | struct dentry *dentry; | |
158 | char dentry_name[NAME_MAX]; | |
159 | #endif | |
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160 | }; |
161 | ||
162 | /* Routines internal to opp core */ | |
163 | struct device_opp *_find_device_opp(struct device *dev); | |
164 | struct device_list_opp *_add_list_dev(const struct device *dev, | |
165 | struct device_opp *dev_opp); | |
166 | struct device_node *_of_get_opp_desc_node(struct device *dev); | |
167 | ||
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168 | #ifdef CONFIG_DEBUG_FS |
169 | void opp_debug_remove_one(struct dev_pm_opp *opp); | |
170 | int opp_debug_create_one(struct dev_pm_opp *opp, struct device_opp *dev_opp); | |
171 | int opp_debug_register(struct device_list_opp *list_dev, | |
172 | struct device_opp *dev_opp); | |
173 | void opp_debug_unregister(struct device_list_opp *list_dev, | |
174 | struct device_opp *dev_opp); | |
175 | #else | |
176 | static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {} | |
177 | ||
178 | static inline int opp_debug_create_one(struct dev_pm_opp *opp, | |
179 | struct device_opp *dev_opp) | |
180 | { return 0; } | |
181 | static inline int opp_debug_register(struct device_list_opp *list_dev, | |
182 | struct device_opp *dev_opp) | |
183 | { return 0; } | |
184 | ||
185 | static inline void opp_debug_unregister(struct device_list_opp *list_dev, | |
186 | struct device_opp *dev_opp) | |
187 | { } | |
188 | #endif /* DEBUG_FS */ | |
189 | ||
f59d3ee8 | 190 | #endif /* __DRIVER_OPP_H__ */ |