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Diffstat (limited to 'drivers/base/power/opp/opp.h')
| -rw-r--r-- | drivers/base/power/opp/opp.h | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h new file mode 100644 index 000000000000..f67f806fcf3a --- /dev/null +++ b/drivers/base/power/opp/opp.h @@ -0,0 +1,207 @@ +/* + * Generic OPP Interface + * + * Copyright (C) 2009-2010 Texas Instruments Incorporated. + * Nishanth Menon + * Romit Dasgupta + * Kevin Hilman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __DRIVER_OPP_H__ +#define __DRIVER_OPP_H__ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/limits.h> +#include <linux/pm_opp.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> + +struct clk; +struct regulator; + +/* Lock to allow exclusive modification to the device and opp lists */ +extern struct mutex opp_table_lock; + +/* + * Internal data structure organization with the OPP layer library is as + * follows: + * opp_tables (root) + * |- device 1 (represents voltage domain 1) + * | |- opp 1 (availability, freq, voltage) + * | |- opp 2 .. + * ... ... + * | `- opp n .. + * |- device 2 (represents the next voltage domain) + * ... + * `- device m (represents mth voltage domain) + * device 1, 2.. are represented by opp_table structure while each opp + * is represented by the opp structure. + */ + +/** + * struct dev_pm_opp - Generic OPP description structure + * @node: opp table node. The nodes are maintained throughout the lifetime + * of boot. It is expected only an optimal set of OPPs are + * added to the library by the SoC framework. + * RCU usage: opp table is traversed with RCU locks. node + * modification is possible realtime, hence the modifications + * are protected by the opp_table_lock for integrity. + * IMPORTANT: the opp nodes should be maintained in increasing + * order. + * @available: true/false - marks if this OPP as available or not + * @dynamic: not-created from static DT entries. + * @turbo: true if turbo (boost) OPP + * @suspend: true if suspend OPP + * @rate: Frequency in hertz + * @u_volt: Target voltage in microvolts corresponding to this OPP + * @u_volt_min: Minimum voltage in microvolts corresponding to this OPP + * @u_volt_max: Maximum voltage in microvolts corresponding to this OPP + * @u_amp: Maximum current drawn by the device in microamperes + * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's + * frequency from any other OPP's frequency. + * @opp_table: points back to the opp_table struct this opp belongs to + * @rcu_head: RCU callback head used for deferred freeing + * @np: OPP's device node. + * @dentry: debugfs dentry pointer (per opp) + * + * This structure stores the OPP information for a given device. + */ +struct dev_pm_opp { + struct list_head node; + + bool available; + bool dynamic; + bool turbo; + bool suspend; + unsigned long rate; + + unsigned long u_volt; + unsigned long u_volt_min; + unsigned long u_volt_max; + unsigned long u_amp; + unsigned long clock_latency_ns; + + struct opp_table *opp_table; + struct rcu_head rcu_head; + + struct device_node *np; + +#ifdef CONFIG_DEBUG_FS + struct dentry *dentry; +#endif +}; + +/** + * struct opp_device - devices managed by 'struct opp_table' + * @node: list node + * @dev: device to which the struct object belongs + * @rcu_head: RCU callback head used for deferred freeing + * @dentry: debugfs dentry pointer (per device) + * + * This is an internal data structure maintaining the devices that are managed + * by 'struct opp_table'. + */ +struct opp_device { + struct list_head node; + const struct device *dev; + struct rcu_head rcu_head; + +#ifdef CONFIG_DEBUG_FS + struct dentry *dentry; +#endif +}; + +/** + * struct opp_table - Device opp structure + * @node: table node - contains the devices with OPPs that + * have been registered. Nodes once added are not modified in this + * table. + * RCU usage: nodes are not modified in the table of opp_table, + * however addition is possible and is secured by opp_table_lock + * @srcu_head: notifier head to notify the OPP availability changes. + * @rcu_head: RCU callback head used for deferred freeing + * @dev_list: list of devices that share these OPPs + * @opp_list: table of opps + * @np: struct device_node pointer for opp's DT node. + * @clock_latency_ns_max: Max clock latency in nanoseconds. + * @shared_opp: OPP is shared between multiple devices. + * @suspend_opp: Pointer to OPP to be used during device suspend. + * @supported_hw: Array of version number to support. + * @supported_hw_count: Number of elements in supported_hw array. + * @prop_name: A name to postfix to many DT properties, while parsing them. + * @clk: Device's clock handle + * @regulator: Supply regulator + * @dentry: debugfs dentry pointer of the real device directory (not links). + * @dentry_name: Name of the real dentry. + * + * @voltage_tolerance_v1: In percentage, for v1 bindings only. + * + * This is an internal data structure maintaining the link to opps attached to + * a device. This structure is not meant to be shared to users as it is + * meant for book keeping and private to OPP library. + * + * Because the opp structures can be used from both rcu and srcu readers, we + * need to wait for the grace period of both of them before freeing any + * resources. And so we have used kfree_rcu() from within call_srcu() handlers. + */ +struct opp_table { + struct list_head node; + + struct srcu_notifier_head srcu_head; + struct rcu_head rcu_head; + struct list_head dev_list; + struct list_head opp_list; + + struct device_node *np; + unsigned long clock_latency_ns_max; + + /* For backward compatibility with v1 bindings */ + unsigned int voltage_tolerance_v1; + + bool shared_opp; + struct dev_pm_opp *suspend_opp; + + unsigned int *supported_hw; + unsigned int supported_hw_count; + const char *prop_name; + struct clk *clk; + struct regulator *regulator; + +#ifdef CONFIG_DEBUG_FS + struct dentry *dentry; + char dentry_name[NAME_MAX]; +#endif +}; + +/* Routines internal to opp core */ +struct opp_table *_find_opp_table(struct device *dev); +struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); +struct device_node *_of_get_opp_desc_node(struct device *dev); + +#ifdef CONFIG_DEBUG_FS +void opp_debug_remove_one(struct dev_pm_opp *opp); +int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table); +int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table); +void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table); +#else +static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {} + +static inline int opp_debug_create_one(struct dev_pm_opp *opp, + struct opp_table *opp_table) +{ return 0; } +static inline int opp_debug_register(struct opp_device *opp_dev, + struct opp_table *opp_table) +{ return 0; } + +static inline void opp_debug_unregister(struct opp_device *opp_dev, + struct opp_table *opp_table) +{ } +#endif /* DEBUG_FS */ + +#endif /* __DRIVER_OPP_H__ */ |