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