/*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/regulator/consumer.h>
#include "opp.h"
/*
* The root of the list of all opp-tables. All opp_table structures branch off
* from here, with each opp_table containing the list of opps it supports in
* various states of availability.
*/
LIST_HEAD(opp_tables);
/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_lock);
#define opp_rcu_lockdep_assert() \
do { \
RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
!lockdep_is_held(&opp_table_lock), \
"Missing rcu_read_lock() or " \
"opp_table_lock protection"); \
} while (0)
static struct opp_device *_find_opp_dev(const struct device *dev,
struct opp_table *opp_table)
{
struct opp_device *opp_dev;
list_for_each_entry(opp_dev, &opp_table->dev_list, node)
if (opp_dev->dev == dev)
return opp_dev;
return NULL;
}
/**
* _find_opp_table() - find opp_table struct using device pointer
* @dev: device pointer used to lookup OPP table
*
* Search OPP table for one containing matching device. Does a RCU reader
* operation to grab the pointer needed.
*
* Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
* -EINVAL based on type of error.
*
* Locking: For readers, this function must be called under rcu_read_lock().
* opp_table is a RCU protected pointer, which means that opp_table is valid
* as long as we are under RCU lock.
*
* For Writers, this function must be called with opp_table_lock held.
*/
struct opp_table *_find_opp_table(struct device *dev)
{
struct opp_table *opp_table;
opp_rcu_lockdep_assert();
if (IS_ERR_OR_NULL(dev)) {
pr_err("%s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
list_for_each_entry_rcu(opp_table, &opp_tables, node)
if (_find_opp_dev(dev, opp_table))
return opp_table;
return ERR_PTR(-ENODEV);
}
/**
* dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
* @opp: opp for which voltage has to be returned for
*
* Return: voltage in micro volt corresponding to the opp, else
* return 0
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* pr
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