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![Tony Lindgren](/assets/img/avatar_default.png)
Instead of BUG(), warn on disabling clocks with no users. Signed-off-by: Tony Lindgren <tony@atomide.com>
447 lines
9.4 KiB
C
447 lines
9.4 KiB
C
/*
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* linux/arch/arm/plat-omap/clock.c
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*
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* Copyright (C) 2004 - 2005 Nokia corporation
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* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
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*
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* Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/version.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <linux/clk.h>
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#include <linux/mutex.h>
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#include <linux/platform_device.h>
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#include <asm/io.h>
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#include <asm/arch/clock.h>
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static LIST_HEAD(clocks);
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static DEFINE_MUTEX(clocks_mutex);
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static DEFINE_SPINLOCK(clockfw_lock);
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static struct clk_functions *arch_clock;
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#ifdef CONFIG_PM_DEBUG
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static void print_parents(struct clk *clk)
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{
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struct clk *p;
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int printed = 0;
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list_for_each_entry(p, &clocks, node) {
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if (p->parent == clk && p->usecount) {
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if (!clk->usecount && !printed) {
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printk("MISMATCH: %s\n", clk->name);
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printed = 1;
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}
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printk("\t%-15s\n", p->name);
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}
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}
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}
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void clk_print_usecounts(void)
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{
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unsigned long flags;
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struct clk *p;
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spin_lock_irqsave(&clockfw_lock, flags);
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list_for_each_entry(p, &clocks, node) {
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if (p->usecount)
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printk("%-15s: %d\n", p->name, p->usecount);
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print_parents(p);
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}
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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#endif
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/*-------------------------------------------------------------------------
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* Standard clock functions defined in include/linux/clk.h
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*-------------------------------------------------------------------------*/
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/*
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* Returns a clock. Note that we first try to use device id on the bus
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* and clock name. If this fails, we try to use clock name only.
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*/
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struct clk * clk_get(struct device *dev, const char *id)
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{
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struct clk *p, *clk = ERR_PTR(-ENOENT);
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int idno;
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if (dev == NULL || dev->bus != &platform_bus_type)
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idno = -1;
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else
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idno = to_platform_device(dev)->id;
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mutex_lock(&clocks_mutex);
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list_for_each_entry(p, &clocks, node) {
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if (p->id == idno &&
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strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
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clk = p;
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goto found;
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}
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}
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list_for_each_entry(p, &clocks, node) {
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if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
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clk = p;
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break;
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}
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}
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found:
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mutex_unlock(&clocks_mutex);
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return clk;
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}
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EXPORT_SYMBOL(clk_get);
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int clk_enable(struct clk *clk)
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{
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unsigned long flags;
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int ret = 0;
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if (clk == NULL || IS_ERR(clk))
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return -EINVAL;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_enable)
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ret = arch_clock->clk_enable(clk);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_enable);
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void clk_disable(struct clk *clk)
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{
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unsigned long flags;
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if (clk == NULL || IS_ERR(clk))
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return;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (clk->usecount == 0) {
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printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
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clk->name);
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WARN_ON(1);
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goto out;
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}
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if (arch_clock->clk_disable)
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arch_clock->clk_disable(clk);
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out:
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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EXPORT_SYMBOL(clk_disable);
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int clk_get_usecount(struct clk *clk)
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{
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unsigned long flags;
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int ret = 0;
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if (clk == NULL || IS_ERR(clk))
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return 0;
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spin_lock_irqsave(&clockfw_lock, flags);
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ret = clk->usecount;
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_get_usecount);
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unsigned long clk_get_rate(struct clk *clk)
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{
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unsigned long flags;
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unsigned long ret = 0;
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if (clk == NULL || IS_ERR(clk))
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return 0;
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spin_lock_irqsave(&clockfw_lock, flags);
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ret = clk->rate;
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_get_rate);
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void clk_put(struct clk *clk)
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{
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if (clk && !IS_ERR(clk))
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module_put(clk->owner);
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}
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EXPORT_SYMBOL(clk_put);
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/*-------------------------------------------------------------------------
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* Optional clock functions defined in include/linux/clk.h
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*-------------------------------------------------------------------------*/
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long clk_round_rate(struct clk *clk, unsigned long rate)
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{
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unsigned long flags;
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long ret = 0;
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if (clk == NULL || IS_ERR(clk))
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return ret;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_round_rate)
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ret = arch_clock->clk_round_rate(clk, rate);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_round_rate);
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int clk_set_rate(struct clk *clk, unsigned long rate)
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{
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unsigned long flags;
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int ret = -EINVAL;
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if (clk == NULL || IS_ERR(clk))
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return ret;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_set_rate)
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ret = arch_clock->clk_set_rate(clk, rate);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_set_rate);
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int clk_set_parent(struct clk *clk, struct clk *parent)
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{
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unsigned long flags;
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int ret = -EINVAL;
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if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
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return ret;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_set_parent)
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ret = arch_clock->clk_set_parent(clk, parent);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_set_parent);
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struct clk *clk_get_parent(struct clk *clk)
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{
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unsigned long flags;
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struct clk * ret = NULL;
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if (clk == NULL || IS_ERR(clk))
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return ret;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_get_parent)
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ret = arch_clock->clk_get_parent(clk);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(clk_get_parent);
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/*-------------------------------------------------------------------------
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* OMAP specific clock functions shared between omap1 and omap2
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*-------------------------------------------------------------------------*/
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unsigned int __initdata mpurate;
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/*
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* By default we use the rate set by the bootloader.
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* You can override this with mpurate= cmdline option.
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*/
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static int __init omap_clk_setup(char *str)
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{
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get_option(&str, &mpurate);
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if (!mpurate)
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return 1;
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if (mpurate < 1000)
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mpurate *= 1000000;
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return 1;
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}
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__setup("mpurate=", omap_clk_setup);
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/* Used for clocks that always have same value as the parent clock */
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void followparent_recalc(struct clk *clk)
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{
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if (clk == NULL || IS_ERR(clk))
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return;
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clk->rate = clk->parent->rate;
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if (unlikely(clk->flags & RATE_PROPAGATES))
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propagate_rate(clk);
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}
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/* Propagate rate to children */
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void propagate_rate(struct clk * tclk)
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{
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struct clk *clkp;
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if (tclk == NULL || IS_ERR(tclk))
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return;
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list_for_each_entry(clkp, &clocks, node) {
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if (likely(clkp->parent != tclk))
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continue;
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if (likely((u32)clkp->recalc))
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clkp->recalc(clkp);
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}
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}
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/**
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* recalculate_root_clocks - recalculate and propagate all root clocks
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*
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* Recalculates all root clocks (clocks with no parent), which if the
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* clock's .recalc is set correctly, should also propagate their rates.
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* Called at init.
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*/
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void recalculate_root_clocks(void)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &clocks, node) {
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if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
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clkp->recalc(clkp);
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}
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}
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int clk_register(struct clk *clk)
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{
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if (clk == NULL || IS_ERR(clk))
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return -EINVAL;
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mutex_lock(&clocks_mutex);
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list_add(&clk->node, &clocks);
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if (clk->init)
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clk->init(clk);
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mutex_unlock(&clocks_mutex);
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return 0;
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}
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EXPORT_SYMBOL(clk_register);
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void clk_unregister(struct clk *clk)
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{
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if (clk == NULL || IS_ERR(clk))
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return;
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mutex_lock(&clocks_mutex);
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list_del(&clk->node);
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mutex_unlock(&clocks_mutex);
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}
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EXPORT_SYMBOL(clk_unregister);
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void clk_deny_idle(struct clk *clk)
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{
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unsigned long flags;
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if (clk == NULL || IS_ERR(clk))
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return;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_deny_idle)
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arch_clock->clk_deny_idle(clk);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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EXPORT_SYMBOL(clk_deny_idle);
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void clk_allow_idle(struct clk *clk)
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{
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unsigned long flags;
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if (clk == NULL || IS_ERR(clk))
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return;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_allow_idle)
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arch_clock->clk_allow_idle(clk);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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EXPORT_SYMBOL(clk_allow_idle);
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void clk_enable_init_clocks(void)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &clocks, node) {
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if (clkp->flags & ENABLE_ON_INIT)
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clk_enable(clkp);
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}
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}
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EXPORT_SYMBOL(clk_enable_init_clocks);
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#ifdef CONFIG_CPU_FREQ
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void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
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{
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unsigned long flags;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_init_cpufreq_table)
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arch_clock->clk_init_cpufreq_table(table);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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EXPORT_SYMBOL(clk_init_cpufreq_table);
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#endif
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/*-------------------------------------------------------------------------*/
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#ifdef CONFIG_OMAP_RESET_CLOCKS
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/*
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* Disable any unused clocks left on by the bootloader
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*/
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static int __init clk_disable_unused(void)
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{
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struct clk *ck;
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unsigned long flags;
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list_for_each_entry(ck, &clocks, node) {
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if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
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ck->enable_reg == 0)
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continue;
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spin_lock_irqsave(&clockfw_lock, flags);
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if (arch_clock->clk_disable_unused)
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arch_clock->clk_disable_unused(ck);
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spin_unlock_irqrestore(&clockfw_lock, flags);
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}
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return 0;
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}
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late_initcall(clk_disable_unused);
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#endif
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int __init clk_init(struct clk_functions * custom_clocks)
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{
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if (!custom_clocks) {
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printk(KERN_ERR "No custom clock functions registered\n");
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BUG();
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}
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arch_clock = custom_clocks;
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return 0;
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}
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