xref: /openbmc/linux/drivers/opp/opp.h (revision d0e22329)
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  * @required_opps: List of OPPs that are required by this OPP.
67  * @opp_table:	points back to the opp_table struct this opp belongs to
68  * @np:		OPP's device node.
69  * @dentry:	debugfs dentry pointer (per opp)
70  *
71  * This structure stores the OPP information for a given device.
72  */
73 struct dev_pm_opp {
74 	struct list_head node;
75 	struct kref kref;
76 
77 	bool available;
78 	bool dynamic;
79 	bool turbo;
80 	bool suspend;
81 	unsigned int pstate;
82 	unsigned long rate;
83 
84 	struct dev_pm_opp_supply *supplies;
85 
86 	unsigned long clock_latency_ns;
87 
88 	struct dev_pm_opp **required_opps;
89 	struct opp_table *opp_table;
90 
91 	struct device_node *np;
92 
93 #ifdef CONFIG_DEBUG_FS
94 	struct dentry *dentry;
95 #endif
96 };
97 
98 /**
99  * struct opp_device - devices managed by 'struct opp_table'
100  * @node:	list node
101  * @dev:	device to which the struct object belongs
102  * @dentry:	debugfs dentry pointer (per device)
103  *
104  * This is an internal data structure maintaining the devices that are managed
105  * by 'struct opp_table'.
106  */
107 struct opp_device {
108 	struct list_head node;
109 	const struct device *dev;
110 
111 #ifdef CONFIG_DEBUG_FS
112 	struct dentry *dentry;
113 #endif
114 };
115 
116 enum opp_table_access {
117 	OPP_TABLE_ACCESS_UNKNOWN = 0,
118 	OPP_TABLE_ACCESS_EXCLUSIVE = 1,
119 	OPP_TABLE_ACCESS_SHARED = 2,
120 };
121 
122 /**
123  * struct opp_table - Device opp structure
124  * @node:	table node - contains the devices with OPPs that
125  *		have been registered. Nodes once added are not modified in this
126  *		table.
127  * @head:	notifier head to notify the OPP availability changes.
128  * @dev_list:	list of devices that share these OPPs
129  * @opp_list:	table of opps
130  * @kref:	for reference count of the table.
131  * @list_kref:	for reference count of the OPP list.
132  * @lock:	mutex protecting the opp_list and dev_list.
133  * @np:		struct device_node pointer for opp's DT node.
134  * @clock_latency_ns_max: Max clock latency in nanoseconds.
135  * @parsed_static_opps: True if OPPs are initialized from DT.
136  * @shared_opp: OPP is shared between multiple devices.
137  * @suspend_opp: Pointer to OPP to be used during device suspend.
138  * @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
139  * @genpd_virt_devs: List of virtual devices for multiple genpd support.
140  * @required_opp_tables: List of device OPP tables that are required by OPPs in
141  *		this table.
142  * @required_opp_count: Number of required devices.
143  * @supported_hw: Array of version number to support.
144  * @supported_hw_count: Number of elements in supported_hw array.
145  * @prop_name: A name to postfix to many DT properties, while parsing them.
146  * @clk: Device's clock handle
147  * @regulators: Supply regulators
148  * @regulator_count: Number of power supply regulators. Its value can be -1
149  * (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
150  * property).
151  * @genpd_performance_state: Device's power domain support performance state.
152  * @is_genpd: Marks if the OPP table belongs to a genpd.
153  * @set_opp: Platform specific set_opp callback
154  * @set_opp_data: Data to be passed to set_opp callback
155  * @dentry:	debugfs dentry pointer of the real device directory (not links).
156  * @dentry_name: Name of the real dentry.
157  *
158  * @voltage_tolerance_v1: In percentage, for v1 bindings only.
159  *
160  * This is an internal data structure maintaining the link to opps attached to
161  * a device. This structure is not meant to be shared to users as it is
162  * meant for book keeping and private to OPP library.
163  */
164 struct opp_table {
165 	struct list_head node;
166 
167 	struct blocking_notifier_head head;
168 	struct list_head dev_list;
169 	struct list_head opp_list;
170 	struct kref kref;
171 	struct kref list_kref;
172 	struct mutex lock;
173 
174 	struct device_node *np;
175 	unsigned long clock_latency_ns_max;
176 
177 	/* For backward compatibility with v1 bindings */
178 	unsigned int voltage_tolerance_v1;
179 
180 	bool parsed_static_opps;
181 	enum opp_table_access shared_opp;
182 	struct dev_pm_opp *suspend_opp;
183 
184 	struct mutex genpd_virt_dev_lock;
185 	struct device **genpd_virt_devs;
186 	struct opp_table **required_opp_tables;
187 	unsigned int required_opp_count;
188 
189 	unsigned int *supported_hw;
190 	unsigned int supported_hw_count;
191 	const char *prop_name;
192 	struct clk *clk;
193 	struct regulator **regulators;
194 	int regulator_count;
195 	bool genpd_performance_state;
196 	bool is_genpd;
197 
198 	int (*set_opp)(struct dev_pm_set_opp_data *data);
199 	struct dev_pm_set_opp_data *set_opp_data;
200 
201 #ifdef CONFIG_DEBUG_FS
202 	struct dentry *dentry;
203 	char dentry_name[NAME_MAX];
204 #endif
205 };
206 
207 /* Routines internal to opp core */
208 void dev_pm_opp_get(struct dev_pm_opp *opp);
209 void _opp_remove_all_static(struct opp_table *opp_table);
210 void _get_opp_table_kref(struct opp_table *opp_table);
211 int _get_opp_count(struct opp_table *opp_table);
212 struct opp_table *_find_opp_table(struct device *dev);
213 struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);
214 void _dev_pm_opp_find_and_remove_table(struct device *dev);
215 struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
216 void _opp_free(struct dev_pm_opp *opp);
217 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
218 int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
219 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, int last_cpu);
220 struct opp_table *_add_opp_table(struct device *dev);
221 void _put_opp_list_kref(struct opp_table *opp_table);
222 
223 #ifdef CONFIG_OF
224 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index);
225 void _of_clear_opp_table(struct opp_table *opp_table);
226 struct opp_table *_managed_opp(struct device *dev, int index);
227 void _of_opp_free_required_opps(struct opp_table *opp_table,
228 				struct dev_pm_opp *opp);
229 #else
230 static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index) {}
231 static inline void _of_clear_opp_table(struct opp_table *opp_table) {}
232 static inline struct opp_table *_managed_opp(struct device *dev, int index) { return NULL; }
233 static inline void _of_opp_free_required_opps(struct opp_table *opp_table,
234 					      struct dev_pm_opp *opp) {}
235 #endif
236 
237 #ifdef CONFIG_DEBUG_FS
238 void opp_debug_remove_one(struct dev_pm_opp *opp);
239 int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table);
240 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table);
241 void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table);
242 #else
243 static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
244 
245 static inline int opp_debug_create_one(struct dev_pm_opp *opp,
246 				       struct opp_table *opp_table)
247 { return 0; }
248 static inline int opp_debug_register(struct opp_device *opp_dev,
249 				     struct opp_table *opp_table)
250 { return 0; }
251 
252 static inline void opp_debug_unregister(struct opp_device *opp_dev,
253 					struct opp_table *opp_table)
254 { }
255 #endif		/* DEBUG_FS */
256 
257 #endif		/* __DRIVER_OPP_H__ */
258