2 * Generic OPP Interface
4 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
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.
14 #ifndef __DRIVER_OPP_H__
15 #define __DRIVER_OPP_H__
17 #include <linux/device.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/limits.h>
21 #include <linux/pm_opp.h>
22 #include <linux/rculist.h>
23 #include <linux/rcupdate.h>
28 /* Lock to allow exclusive modification to the device and opp lists */
29 extern struct mutex opp_table_lock;
31 extern struct list_head opp_tables;
34 * Internal data structure organization with the OPP layer library is as
37 * |- device 1 (represents voltage domain 1)
38 * | |- opp 1 (availability, freq, voltage)
42 * |- device 2 (represents the next voltage domain)
44 * `- device m (represents mth voltage domain)
45 * device 1, 2.. are represented by opp_table structure while each opp
46 * is represented by the opp structure.
50 * struct dev_pm_opp - Generic OPP description structure
51 * @node: opp table node. The nodes are maintained throughout the lifetime
52 * of boot. It is expected only an optimal set of OPPs are
53 * added to the library by the SoC framework.
54 * RCU usage: opp table is traversed with RCU locks. node
55 * modification is possible realtime, hence the modifications
56 * are protected by the opp_table_lock for integrity.
57 * IMPORTANT: the opp nodes should be maintained in increasing
59 * @available: true/false - marks if this OPP as available or not
60 * @dynamic: not-created from static DT entries.
61 * @turbo: true if turbo (boost) OPP
62 * @suspend: true if suspend OPP
63 * @rate: Frequency in hertz
64 * @supplies: Power supplies voltage/current values
65 * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
66 * frequency from any other OPP's frequency.
67 * @opp_table: points back to the opp_table struct this opp belongs to
68 * @rcu_head: RCU callback head used for deferred freeing
69 * @np: OPP's device node.
70 * @dentry: debugfs dentry pointer (per opp)
72 * This structure stores the OPP information for a given device.
75 struct list_head node;
83 struct dev_pm_opp_supply *supplies;
85 unsigned long clock_latency_ns;
87 struct opp_table *opp_table;
88 struct rcu_head rcu_head;
90 struct device_node *np;
92 #ifdef CONFIG_DEBUG_FS
93 struct dentry *dentry;
98 * struct opp_device - devices managed by 'struct opp_table'
100 * @dev: device to which the struct object belongs
101 * @rcu_head: RCU callback head used for deferred freeing
102 * @dentry: debugfs dentry pointer (per device)
104 * This is an internal data structure maintaining the devices that are managed
105 * by 'struct opp_table'.
108 struct list_head node;
109 const struct device *dev;
110 struct rcu_head rcu_head;
112 #ifdef CONFIG_DEBUG_FS
113 struct dentry *dentry;
117 enum opp_table_access {
118 OPP_TABLE_ACCESS_UNKNOWN = 0,
119 OPP_TABLE_ACCESS_EXCLUSIVE = 1,
120 OPP_TABLE_ACCESS_SHARED = 2,
124 * struct opp_table - Device opp structure
125 * @node: table node - contains the devices with OPPs that
126 * have been registered. Nodes once added are not modified in this
128 * RCU usage: nodes are not modified in the table of opp_table,
129 * however addition is possible and is secured by opp_table_lock
130 * @srcu_head: notifier head to notify the OPP availability changes.
131 * @rcu_head: RCU callback head used for deferred freeing
132 * @dev_list: list of devices that share these OPPs
133 * @opp_list: table of opps
134 * @kref: for reference count of the table.
135 * @lock: mutex protecting the opp_list.
136 * @np: struct device_node pointer for opp's DT node.
137 * @clock_latency_ns_max: Max clock latency in nanoseconds.
138 * @shared_opp: OPP is shared between multiple devices.
139 * @suspend_opp: Pointer to OPP to be used during device suspend.
140 * @supported_hw: Array of version number to support.
141 * @supported_hw_count: Number of elements in supported_hw array.
142 * @prop_name: A name to postfix to many DT properties, while parsing them.
143 * @clk: Device's clock handle
144 * @regulators: Supply regulators
145 * @regulator_count: Number of power supply regulators
146 * @set_opp: Platform specific set_opp callback
147 * @set_opp_data: Data to be passed to set_opp callback
148 * @dentry: debugfs dentry pointer of the real device directory (not links).
149 * @dentry_name: Name of the real dentry.
151 * @voltage_tolerance_v1: In percentage, for v1 bindings only.
153 * This is an internal data structure maintaining the link to opps attached to
154 * a device. This structure is not meant to be shared to users as it is
155 * meant for book keeping and private to OPP library.
157 * Because the opp structures can be used from both rcu and srcu readers, we
158 * need to wait for the grace period of both of them before freeing any
159 * resources. And so we have used kfree_rcu() from within call_srcu() handlers.
162 struct list_head node;
164 struct srcu_notifier_head srcu_head;
165 struct rcu_head rcu_head;
166 struct list_head dev_list;
167 struct list_head opp_list;
171 struct device_node *np;
172 unsigned long clock_latency_ns_max;
174 /* For backward compatibility with v1 bindings */
175 unsigned int voltage_tolerance_v1;
177 enum opp_table_access shared_opp;
178 struct dev_pm_opp *suspend_opp;
180 unsigned int *supported_hw;
181 unsigned int supported_hw_count;
182 const char *prop_name;
184 struct regulator **regulators;
185 unsigned int regulator_count;
187 int (*set_opp)(struct dev_pm_set_opp_data *data);
188 struct dev_pm_set_opp_data *set_opp_data;
190 #ifdef CONFIG_DEBUG_FS
191 struct dentry *dentry;
192 char dentry_name[NAME_MAX];
196 /* Routines internal to opp core */
197 void _get_opp_table_kref(struct opp_table *opp_table);
198 struct opp_table *_find_opp_table(struct device *dev);
199 struct opp_table *_add_opp_table(struct device *dev);
200 struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);
201 void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, bool remove_all);
202 void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all);
203 struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
204 void _opp_free(struct dev_pm_opp *opp);
205 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table);
206 int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
207 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of);
208 struct opp_table *_add_opp_table(struct device *dev);
211 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev);
213 static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev) {}
216 #ifdef CONFIG_DEBUG_FS
217 void opp_debug_remove_one(struct dev_pm_opp *opp);
218 int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table);
219 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table);
220 void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table);
222 static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
224 static inline int opp_debug_create_one(struct dev_pm_opp *opp,
225 struct opp_table *opp_table)
227 static inline int opp_debug_register(struct opp_device *opp_dev,
228 struct opp_table *opp_table)
231 static inline void opp_debug_unregister(struct opp_device *opp_dev,
232 struct opp_table *opp_table)
234 #endif /* DEBUG_FS */
236 #endif /* __DRIVER_OPP_H__ */