137b3ee27a
debugfs can provide the infrastructure to trace the dependencies of clock tree hierarchy quite visibly. This patch enables to keep track of clock tree hierarchy and expose their attributes under each clock directry as below: omap:~# tree -d -L 2 /debug/clock/omap_32k_fck/ /debug/clock/omap_32k_fck/ |-- gpt10_fck |-- gpt11_fck |-- gpt1_fck |-- per_32k_alwon_fck | |-- gpio2_fck | |-- gpio3_fck | |-- gpio4_fck | |-- gpio5_fck | |-- gpio6_fck | `-- wdt3_fck |-- ts_fck `-- wkup_32k_fck |-- gpio1_fck `-- wdt2_fck 14 directories omap:~# tree /debug/clock/omap_32k_fck/gpt10_fck/ /debug/clock/omap_32k_fck/gpt10_fck/ |-- flags |-- rate `-- usecount 0 directories, 3 files Although, compared with David Brownell's small patch, this may look bit overkilling, I expect that this debugfs can deal with other PRCM complexities at the same time. For example, powerdomain dependencies can be expressed by using symbolic links of these clocks if powerdomain supports dubgfs as well. Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
505 lines
11 KiB
C
505 lines
11 KiB
C
/*
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* linux/arch/arm/plat-omap/clock.c
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*
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* Copyright (C) 2004 - 2008 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 <linux/cpufreq.h>
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#include <linux/debugfs.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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/*-------------------------------------------------------------------------
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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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#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
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/*
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* debugfs support to trace clock tree hierarchy and attributes
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*/
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static struct dentry *clk_debugfs_root;
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static int clk_debugfs_register_one(struct clk *c)
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{
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int err;
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struct dentry *d, *child;
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struct clk *pa = c->parent;
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char s[255];
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char *p = s;
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p += sprintf(p, "%s", c->name);
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if (c->id != 0)
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sprintf(p, ":%d", c->id);
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d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
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if (IS_ERR(d))
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return PTR_ERR(d);
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c->dent = d;
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d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
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if (IS_ERR(d)) {
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err = PTR_ERR(d);
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goto err_out;
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}
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d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
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if (IS_ERR(d)) {
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err = PTR_ERR(d);
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goto err_out;
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}
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d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
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if (IS_ERR(d)) {
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err = PTR_ERR(d);
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goto err_out;
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}
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return 0;
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err_out:
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d = c->dent;
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list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
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debugfs_remove(child);
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debugfs_remove(c->dent);
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return err;
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}
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static int clk_debugfs_register(struct clk *c)
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{
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int err;
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struct clk *pa = c->parent;
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if (pa && !pa->dent) {
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err = clk_debugfs_register(pa);
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if (err)
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return err;
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}
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if (!c->dent) {
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err = clk_debugfs_register_one(c);
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if (err)
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return err;
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}
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return 0;
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}
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static int __init clk_debugfs_init(void)
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{
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struct clk *c;
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struct dentry *d;
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int err;
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d = debugfs_create_dir("clock", NULL);
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if (IS_ERR(d))
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return PTR_ERR(d);
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clk_debugfs_root = d;
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list_for_each_entry(c, &clocks, node) {
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err = clk_debugfs_register(c);
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if (err)
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goto err_out;
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}
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return 0;
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err_out:
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debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
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return err;
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}
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late_initcall(clk_debugfs_init);
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#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */
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