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/list.h> 20#include <linux/limits.h> 21#include <linux/pm_opp.h> 22#include <linux/rculist.h> 23#include <linux/rcupdate.h> 24 25struct clk; 26struct regulator; 27 28/* Lock to allow exclusive modification to the device and opp lists */ 29extern struct mutex opp_table_lock; 30 31extern 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 * 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 58 * order. 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 * @u_volt: Target voltage in microvolts corresponding to this OPP 65 * @u_volt_min: Minimum voltage in microvolts corresponding to this OPP 66 * @u_volt_max: Maximum voltage in microvolts corresponding to this OPP 67 * @u_amp: Maximum current drawn by the device in microamperes 68 * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's 69 * frequency from any other OPP's frequency. 70 * @opp_table: points back to the opp_table struct this opp belongs to 71 * @rcu_head: RCU callback head used for deferred freeing 72 * @np: OPP's device node. 73 * @dentry: debugfs dentry pointer (per opp) 74 * 75 * This structure stores the OPP information for a given device. 76 */ 77struct dev_pm_opp { 78 struct list_head node; 79 80 bool available; 81 bool dynamic; 82 bool turbo; 83 bool suspend; 84 unsigned long rate; 85 86 unsigned long u_volt; 87 unsigned long u_volt_min; 88 unsigned long u_volt_max; 89 unsigned long u_amp; 90 unsigned long clock_latency_ns; 91 92 struct opp_table *opp_table; 93 struct rcu_head rcu_head; 94 95 struct device_node *np; 96 97#ifdef CONFIG_DEBUG_FS 98 struct dentry *dentry; 99#endif 100}; 101 102/** 103 * struct opp_device - devices managed by 'struct opp_table' 104 * @node: list node 105 * @dev: device to which the struct object belongs 106 * @rcu_head: RCU callback head used for deferred freeing 107 * @dentry: debugfs dentry pointer (per device) 108 * 109 * This is an internal data structure maintaining the devices that are managed 110 * by 'struct opp_table'. 111 */ 112struct opp_device { 113 struct list_head node; 114 const struct device *dev; 115 struct rcu_head rcu_head; 116 117#ifdef CONFIG_DEBUG_FS 118 struct dentry *dentry; 119#endif 120}; 121 122enum opp_table_access { 123 OPP_TABLE_ACCESS_UNKNOWN = 0, 124 OPP_TABLE_ACCESS_EXCLUSIVE = 1, 125 OPP_TABLE_ACCESS_SHARED = 2, 126}; 127 128/** 129 * struct opp_table - Device opp structure 130 * @node: table node - contains the devices with OPPs that 131 * have been registered. Nodes once added are not modified in this 132 * table. 133 * RCU usage: nodes are not modified in the table of opp_table, 134 * however addition is possible and is secured by opp_table_lock 135 * @srcu_head: notifier head to notify the OPP availability changes. 136 * @rcu_head: RCU callback head used for deferred freeing 137 * @dev_list: list of devices that share these OPPs 138 * @opp_list: table of opps 139 * @np: struct device_node pointer for opp's DT node. 140 * @clock_latency_ns_max: Max clock latency in nanoseconds. 141 * @shared_opp: OPP is shared between multiple devices. 142 * @suspend_opp: Pointer to OPP to be used during device suspend. 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 * @regulator: Supply regulator 148 * @dentry: debugfs dentry pointer of the real device directory (not links). 149 * @dentry_name: Name of the real dentry. 150 * 151 * @voltage_tolerance_v1: In percentage, for v1 bindings only. 152 * 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. 156 * 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. 160 */ 161struct opp_table { 162 struct list_head node; 163 164 struct srcu_notifier_head srcu_head; 165 struct rcu_head rcu_head; 166 struct list_head dev_list; 167 struct list_head opp_list; 168 169 struct device_node *np; 170 unsigned long clock_latency_ns_max; 171 172 /* For backward compatibility with v1 bindings */ 173 unsigned int voltage_tolerance_v1; 174 175 enum opp_table_access shared_opp; 176 struct dev_pm_opp *suspend_opp; 177 178 unsigned int *supported_hw; 179 unsigned int supported_hw_count; 180 const char *prop_name; 181 struct clk *clk; 182 struct regulator *regulator; 183 184#ifdef CONFIG_DEBUG_FS 185 struct dentry *dentry; 186 char dentry_name[NAME_MAX]; 187#endif 188}; 189 190/* Routines internal to opp core */ 191struct opp_table *_find_opp_table(struct device *dev); 192struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); 193struct device_node *_of_get_opp_desc_node(struct device *dev); 194void _dev_pm_opp_remove_table(struct device *dev, bool remove_all); 195struct dev_pm_opp *_allocate_opp(struct device *dev, struct opp_table **opp_table); 196int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table); 197void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp, bool notify); 198int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, bool dynamic); 199void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of); 200 201#ifdef CONFIG_OF 202void _of_init_opp_table(struct opp_table *opp_table, struct device *dev); 203#else 204static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev) {} 205#endif 206 207#ifdef CONFIG_DEBUG_FS 208void opp_debug_remove_one(struct dev_pm_opp *opp); 209int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table); 210int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table); 211void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table); 212#else 213static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {} 214 215static inline int opp_debug_create_one(struct dev_pm_opp *opp, 216 struct opp_table *opp_table) 217{ return 0; } 218static inline int opp_debug_register(struct opp_device *opp_dev, 219 struct opp_table *opp_table) 220{ return 0; } 221 222static inline void opp_debug_unregister(struct opp_device *opp_dev, 223 struct opp_table *opp_table) 224{ } 225#endif /* DEBUG_FS */ 226 227#endif /* __DRIVER_OPP_H__ */ 228