xref: /openbmc/linux/drivers/opp/opp.h (revision 93f5715e)
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/kref.h>
20 #include <linux/list.h>
21 #include <linux/limits.h>
22 #include <linux/pm_opp.h>
23 #include <linux/notifier.h>
24 
25 struct clk;
26 struct regulator;
27 
28 /* Lock to allow exclusive modification to the device and opp lists */
29 extern struct mutex opp_table_lock;
30 
31 extern struct list_head opp_tables;
32 
33 /*
34  * Internal data structure organization with the OPP layer library is as
35  * follows:
36  * opp_tables (root)
37  *	|- device 1 (represents voltage domain 1)
38  *	|	|- opp 1 (availability, freq, voltage)
39  *	|	|- opp 2 ..
40  *	...	...
41  *	|	`- opp n ..
42  *	|- device 2 (represents the next voltage domain)
43  *	...
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.
47  */
48 
49 /**
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  *		IMPORTANT: the opp nodes should be maintained in increasing
55  *		order.
56  * @kref:	for reference count of the OPP.
57  * @available:	true/false - marks if this OPP as available or not
58  * @dynamic:	not-created from static DT entries.
59  * @turbo:	true if turbo (boost) OPP
60  * @suspend:	true if suspend OPP
61  * @pstate: Device's power domain's performance state.
62  * @rate:	Frequency in hertz
63  * @supplies:	Power supplies voltage/current values
64  * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
65  *		frequency from any other OPP's frequency.
66  * @opp_table:	points back to the opp_table struct this opp belongs to
67  * @np:		OPP's device node.
68  * @dentry:	debugfs dentry pointer (per opp)
69  *
70  * This structure stores the OPP information for a given device.
71  */
72 struct dev_pm_opp {
73 	struct list_head node;
74 	struct kref kref;
75 
76 	bool available;
77 	bool dynamic;
78 	bool turbo;
79 	bool suspend;
80 	unsigned int pstate;
81 	unsigned long rate;
82 
83 	struct dev_pm_opp_supply *supplies;
84 
85 	unsigned long clock_latency_ns;
86 
87 	struct opp_table *opp_table;
88 
89 	struct device_node *np;
90 
91 #ifdef CONFIG_DEBUG_FS
92 	struct dentry *dentry;
93 #endif
94 };
95 
96 /**
97  * struct opp_device - devices managed by 'struct opp_table'
98  * @node:	list node
99  * @dev:	device to which the struct object belongs
100  * @dentry:	debugfs dentry pointer (per device)
101  *
102  * This is an internal data structure maintaining the devices that are managed
103  * by 'struct opp_table'.
104  */
105 struct opp_device {
106 	struct list_head node;
107 	const struct device *dev;
108 
109 #ifdef CONFIG_DEBUG_FS
110 	struct dentry *dentry;
111 #endif
112 };
113 
114 enum opp_table_access {
115 	OPP_TABLE_ACCESS_UNKNOWN = 0,
116 	OPP_TABLE_ACCESS_EXCLUSIVE = 1,
117 	OPP_TABLE_ACCESS_SHARED = 2,
118 };
119 
120 /**
121  * struct opp_table - Device opp structure
122  * @node:	table node - contains the devices with OPPs that
123  *		have been registered. Nodes once added are not modified in this
124  *		table.
125  * @head:	notifier head to notify the OPP availability changes.
126  * @dev_list:	list of devices that share these OPPs
127  * @opp_list:	table of opps
128  * @kref:	for reference count of the table.
129  * @lock:	mutex protecting the opp_list.
130  * @np:		struct device_node pointer for opp's DT node.
131  * @clock_latency_ns_max: Max clock latency in nanoseconds.
132  * @shared_opp: OPP is shared between multiple devices.
133  * @suspend_opp: Pointer to OPP to be used during device suspend.
134  * @supported_hw: Array of version number to support.
135  * @supported_hw_count: Number of elements in supported_hw array.
136  * @prop_name: A name to postfix to many DT properties, while parsing them.
137  * @clk: Device's clock handle
138  * @regulators: Supply regulators
139  * @regulator_count: Number of power supply regulators
140  * @genpd_performance_state: Device's power domain support performance state.
141  * @set_opp: Platform specific set_opp callback
142  * @set_opp_data: Data to be passed to set_opp callback
143  * @dentry:	debugfs dentry pointer of the real device directory (not links).
144  * @dentry_name: Name of the real dentry.
145  *
146  * @voltage_tolerance_v1: In percentage, for v1 bindings only.
147  *
148  * This is an internal data structure maintaining the link to opps attached to
149  * a device. This structure is not meant to be shared to users as it is
150  * meant for book keeping and private to OPP library.
151  */
152 struct opp_table {
153 	struct list_head node;
154 
155 	struct blocking_notifier_head head;
156 	struct list_head dev_list;
157 	struct list_head opp_list;
158 	struct kref kref;
159 	struct mutex lock;
160 
161 	struct device_node *np;
162 	unsigned long clock_latency_ns_max;
163 
164 	/* For backward compatibility with v1 bindings */
165 	unsigned int voltage_tolerance_v1;
166 
167 	enum opp_table_access shared_opp;
168 	struct dev_pm_opp *suspend_opp;
169 
170 	unsigned int *supported_hw;
171 	unsigned int supported_hw_count;
172 	const char *prop_name;
173 	struct clk *clk;
174 	struct regulator **regulators;
175 	unsigned int regulator_count;
176 	bool genpd_performance_state;
177 
178 	int (*set_opp)(struct dev_pm_set_opp_data *data);
179 	struct dev_pm_set_opp_data *set_opp_data;
180 
181 #ifdef CONFIG_DEBUG_FS
182 	struct dentry *dentry;
183 	char dentry_name[NAME_MAX];
184 #endif
185 };
186 
187 /* Routines internal to opp core */
188 void dev_pm_opp_get(struct dev_pm_opp *opp);
189 void _get_opp_table_kref(struct opp_table *opp_table);
190 int _get_opp_count(struct opp_table *opp_table);
191 struct opp_table *_find_opp_table(struct device *dev);
192 struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);
193 void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, bool remove_all);
194 void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all);
195 struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
196 void _opp_free(struct dev_pm_opp *opp);
197 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
198 int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
199 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of);
200 struct opp_table *_add_opp_table(struct device *dev);
201 
202 #ifdef CONFIG_OF
203 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev);
204 #else
205 static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev) {}
206 #endif
207 
208 #ifdef CONFIG_DEBUG_FS
209 void opp_debug_remove_one(struct dev_pm_opp *opp);
210 int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table);
211 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table);
212 void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table);
213 #else
214 static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
215 
216 static inline int opp_debug_create_one(struct dev_pm_opp *opp,
217 				       struct opp_table *opp_table)
218 { return 0; }
219 static inline int opp_debug_register(struct opp_device *opp_dev,
220 				     struct opp_table *opp_table)
221 { return 0; }
222 
223 static inline void opp_debug_unregister(struct opp_device *opp_dev,
224 					struct opp_table *opp_table)
225 { }
226 #endif		/* DEBUG_FS */
227 
228 #endif		/* __DRIVER_OPP_H__ */
229