linux/arch/arm/mach-msm/clock.c

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/* arch/arm/mach-msm/clock.c
*
* Copyright (C) 2007 Google, Inc.
* Copyright (c) 2007-2010, Code Aurora Forum. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/pm_qos_params.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/clkdev.h>
#include "clock.h"
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clocks_lock);
static LIST_HEAD(clocks);
/*
* Standard clock functions defined in include/linux/clk.h
*/
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clocks_lock, flags);
clk->count++;
if (clk->count == 1)
clk->ops->enable(clk->id);
spin_unlock_irqrestore(&clocks_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clocks_lock, flags);
BUG_ON(clk->count == 0);
clk->count--;
if (clk->count == 0)
clk->ops->disable(clk->id);
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
int clk_reset(struct clk *clk, enum clk_reset_action action)
{
return clk->ops->reset(clk->remote_id, action);
}
EXPORT_SYMBOL(clk_reset);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->ops->get_rate(clk->id);
}
EXPORT_SYMBOL(clk_get_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
int ret;
if (clk->flags & CLKFLAG_MAX) {
ret = clk->ops->set_max_rate(clk->id, rate);
if (ret)
return ret;
}
if (clk->flags & CLKFLAG_MIN) {
ret = clk->ops->set_min_rate(clk->id, rate);
if (ret)
return ret;
}
if (clk->flags & CLKFLAG_MAX || clk->flags & CLKFLAG_MIN)
return ret;
return clk->ops->set_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_set_rate);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
return clk->ops->round_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_round_rate);
int clk_set_min_rate(struct clk *clk, unsigned long rate)
{
return clk->ops->set_min_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_set_min_rate);
int clk_set_max_rate(struct clk *clk, unsigned long rate)
{
return clk->ops->set_max_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_set_max_rate);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
return -ENOSYS;
}
EXPORT_SYMBOL(clk_set_parent);
struct clk *clk_get_parent(struct clk *clk)
{
return ERR_PTR(-ENOSYS);
}
EXPORT_SYMBOL(clk_get_parent);
int clk_set_flags(struct clk *clk, unsigned long flags)
{
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
return clk->ops->set_flags(clk->id, flags);
}
EXPORT_SYMBOL(clk_set_flags);
/* EBI1 is the only shared clock that several clients want to vote on as of
* this commit. If this changes in the future, then it might be better to
* make clk_min_rate handle the voting or make ebi1_clk_set_min_rate more
* generic to support different clocks.
*/
static struct clk *ebi1_clk;
void __init msm_clock_init(struct clk_lookup *clock_tbl, unsigned num_clocks)
{
unsigned n;
mutex_lock(&clocks_mutex);
for (n = 0; n < num_clocks; n++) {
clkdev_add(&clock_tbl[n]);
list_add_tail(&clock_tbl[n].clk->list, &clocks);
}
mutex_unlock(&clocks_mutex);
ebi1_clk = clk_get(NULL, "ebi1_clk");
BUG_ON(ebi1_clk == NULL);
}
/* The bootloader and/or AMSS may have left various clocks enabled.
* Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
* not been explicitly enabled by a clk_enable() call.
*/
static int __init clock_late_init(void)
{
unsigned long flags;
struct clk *clk;
unsigned count = 0;
clock_debug_init();
mutex_lock(&clocks_mutex);
list_for_each_entry(clk, &clocks, list) {
clock_debug_add(clk);
if (clk->flags & CLKFLAG_AUTO_OFF) {
spin_lock_irqsave(&clocks_lock, flags);
if (!clk->count) {
count++;
clk->ops->auto_off(clk->id);
}
spin_unlock_irqrestore(&clocks_lock, flags);
}
}
mutex_unlock(&clocks_mutex);
pr_info("clock_late_init() disabled %d unused clocks\n", count);
return 0;
}
late_initcall(clock_late_init);