xref: /openbmc/linux/drivers/opp/opp.h (revision 3e30a927)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Generic OPP Interface
4  *
5  * Copyright (C) 2009-2010 Texas Instruments Incorporated.
6  *	Nishanth Menon
7  *	Romit Dasgupta
8  *	Kevin Hilman
9  */
10 
11 #ifndef __DRIVER_OPP_H__
12 #define __DRIVER_OPP_H__
13 
14 #include <linux/device.h>
15 #include <linux/kernel.h>
16 #include <linux/kref.h>
17 #include <linux/list.h>
18 #include <linux/limits.h>
19 #include <linux/pm_opp.h>
20 #include <linux/notifier.h>
21 
22 struct clk;
23 struct regulator;
24 
25 /* Lock to allow exclusive modification to the device and opp lists */
26 extern struct mutex opp_table_lock;
27 
28 extern struct list_head opp_tables;
29 
30 /*
31  * Internal data structure organization with the OPP layer library is as
32  * follows:
33  * opp_tables (root)
34  *	|- device 1 (represents voltage domain 1)
35  *	|	|- opp 1 (availability, freq, voltage)
36  *	|	|- opp 2 ..
37  *	...	...
38  *	|	`- opp n ..
39  *	|- device 2 (represents the next voltage domain)
40  *	...
41  *	`- device m (represents mth voltage domain)
42  * device 1, 2.. are represented by opp_table structure while each opp
43  * is represented by the opp structure.
44  */
45 
46 /**
47  * struct dev_pm_opp - Generic OPP description structure
48  * @node:	opp table node. The nodes are maintained throughout the lifetime
49  *		of boot. It is expected only an optimal set of OPPs are
50  *		added to the library by the SoC framework.
51  *		IMPORTANT: the opp nodes should be maintained in increasing
52  *		order.
53  * @kref:	for reference count of the OPP.
54  * @available:	true/false - marks if this OPP as available or not
55  * @dynamic:	not-created from static DT entries.
56  * @turbo:	true if turbo (boost) OPP
57  * @suspend:	true if suspend OPP
58  * @pstate: Device's power domain's performance state.
59  * @rate:	Frequency in hertz
60  * @level:	Performance level
61  * @supplies:	Power supplies voltage/current values
62  * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
63  *		frequency from any other OPP's frequency.
64  * @required_opps: List of OPPs that are required by this OPP.
65  * @opp_table:	points back to the opp_table struct this opp belongs to
66  * @np:		OPP's device node.
67  * @dentry:	debugfs dentry pointer (per opp)
68  *
69  * This structure stores the OPP information for a given device.
70  */
71 struct dev_pm_opp {
72 	struct list_head node;
73 	struct kref kref;
74 
75 	bool available;
76 	bool dynamic;
77 	bool turbo;
78 	bool suspend;
79 	unsigned int pstate;
80 	unsigned long rate;
81 	unsigned int level;
82 
83 	struct dev_pm_opp_supply *supplies;
84 
85 	unsigned long clock_latency_ns;
86 
87 	struct dev_pm_opp **required_opps;
88 	struct opp_table *opp_table;
89 
90 	struct device_node *np;
91 
92 #ifdef CONFIG_DEBUG_FS
93 	struct dentry *dentry;
94 #endif
95 };
96 
97 /**
98  * struct opp_device - devices managed by 'struct opp_table'
99  * @node:	list node
100  * @dev:	device to which the struct object belongs
101  * @dentry:	debugfs dentry pointer (per device)
102  *
103  * This is an internal data structure maintaining the devices that are managed
104  * by 'struct opp_table'.
105  */
106 struct opp_device {
107 	struct list_head node;
108 	const struct device *dev;
109 
110 #ifdef CONFIG_DEBUG_FS
111 	struct dentry *dentry;
112 #endif
113 };
114 
115 enum opp_table_access {
116 	OPP_TABLE_ACCESS_UNKNOWN = 0,
117 	OPP_TABLE_ACCESS_EXCLUSIVE = 1,
118 	OPP_TABLE_ACCESS_SHARED = 2,
119 };
120 
121 /**
122  * struct opp_table - Device opp structure
123  * @node:	table node - contains the devices with OPPs that
124  *		have been registered. Nodes once added are not modified in this
125  *		table.
126  * @head:	notifier head to notify the OPP availability changes.
127  * @dev_list:	list of devices that share these OPPs
128  * @opp_list:	table of opps
129  * @kref:	for reference count of the table.
130  * @lock:	mutex protecting the opp_list and dev_list.
131  * @np:		struct device_node pointer for opp's DT node.
132  * @clock_latency_ns_max: Max clock latency in nanoseconds.
133  * @parsed_static_opps: Count of devices for which OPPs are initialized from DT.
134  * @shared_opp: OPP is shared between multiple devices.
135  * @suspend_opp: Pointer to OPP to be used during device suspend.
136  * @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
137  * @genpd_virt_devs: List of virtual devices for multiple genpd support.
138  * @required_opp_tables: List of device OPP tables that are required by OPPs in
139  *		this table.
140  * @required_opp_count: Number of required devices.
141  * @supported_hw: Array of version number to support.
142  * @supported_hw_count: Number of elements in supported_hw array.
143  * @prop_name: A name to postfix to many DT properties, while parsing them.
144  * @clk: Device's clock handle
145  * @regulators: Supply regulators
146  * @regulator_count: Number of power supply regulators. Its value can be -1
147  * (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
148  * property).
149  * @genpd_performance_state: Device's power domain support performance state.
150  * @is_genpd: Marks if the OPP table belongs to a genpd.
151  * @set_opp: Platform specific set_opp callback
152  * @set_opp_data: Data to be passed to set_opp callback
153  * @dentry:	debugfs dentry pointer of the real device directory (not links).
154  * @dentry_name: Name of the real dentry.
155  *
156  * @voltage_tolerance_v1: In percentage, for v1 bindings only.
157  *
158  * This is an internal data structure maintaining the link to opps attached to
159  * a device. This structure is not meant to be shared to users as it is
160  * meant for book keeping and private to OPP library.
161  */
162 struct opp_table {
163 	struct list_head node;
164 
165 	struct blocking_notifier_head head;
166 	struct list_head dev_list;
167 	struct list_head opp_list;
168 	struct kref kref;
169 	struct mutex lock;
170 
171 	struct device_node *np;
172 	unsigned long clock_latency_ns_max;
173 
174 	/* For backward compatibility with v1 bindings */
175 	unsigned int voltage_tolerance_v1;
176 
177 	unsigned int parsed_static_opps;
178 	enum opp_table_access shared_opp;
179 	struct dev_pm_opp *suspend_opp;
180 
181 	struct mutex genpd_virt_dev_lock;
182 	struct device **genpd_virt_devs;
183 	struct opp_table **required_opp_tables;
184 	unsigned int required_opp_count;
185 
186 	unsigned int *supported_hw;
187 	unsigned int supported_hw_count;
188 	const char *prop_name;
189 	struct clk *clk;
190 	struct regulator **regulators;
191 	int regulator_count;
192 	bool genpd_performance_state;
193 	bool is_genpd;
194 
195 	int (*set_opp)(struct dev_pm_set_opp_data *data);
196 	struct dev_pm_set_opp_data *set_opp_data;
197 
198 #ifdef CONFIG_DEBUG_FS
199 	struct dentry *dentry;
200 	char dentry_name[NAME_MAX];
201 #endif
202 };
203 
204 /* Routines internal to opp core */
205 void dev_pm_opp_get(struct dev_pm_opp *opp);
206 void _opp_remove_all_static(struct opp_table *opp_table);
207 void _get_opp_table_kref(struct opp_table *opp_table);
208 int _get_opp_count(struct opp_table *opp_table);
209 struct opp_table *_find_opp_table(struct device *dev);
210 struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);
211 void _dev_pm_opp_find_and_remove_table(struct device *dev);
212 struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
213 void _opp_free(struct dev_pm_opp *opp);
214 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
215 int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
216 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, int last_cpu);
217 struct opp_table *_add_opp_table(struct device *dev);
218 void _put_opp_list_kref(struct opp_table *opp_table);
219 
220 #ifdef CONFIG_OF
221 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index);
222 void _of_clear_opp_table(struct opp_table *opp_table);
223 struct opp_table *_managed_opp(struct device *dev, int index);
224 void _of_opp_free_required_opps(struct opp_table *opp_table,
225 				struct dev_pm_opp *opp);
226 #else
227 static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index) {}
228 static inline void _of_clear_opp_table(struct opp_table *opp_table) {}
229 static inline struct opp_table *_managed_opp(struct device *dev, int index) { return NULL; }
230 static inline void _of_opp_free_required_opps(struct opp_table *opp_table,
231 					      struct dev_pm_opp *opp) {}
232 #endif
233 
234 #ifdef CONFIG_DEBUG_FS
235 void opp_debug_remove_one(struct dev_pm_opp *opp);
236 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table);
237 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table);
238 void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table);
239 #else
240 static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
241 
242 static inline void opp_debug_create_one(struct dev_pm_opp *opp,
243 					struct opp_table *opp_table) { }
244 
245 static inline void opp_debug_register(struct opp_device *opp_dev,
246 				      struct opp_table *opp_table) { }
247 
248 static inline void opp_debug_unregister(struct opp_device *opp_dev,
249 					struct opp_table *opp_table)
250 { }
251 #endif		/* DEBUG_FS */
252 
253 #endif		/* __DRIVER_OPP_H__ */
254