486 lines
10 KiB
C
486 lines
10 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/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 <linux/io.h>
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#include <plat/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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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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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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/*-------------------------------------------------------------------------
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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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if (ret == 0) {
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if (clk->recalc)
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clk->rate = clk->recalc(clk);
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propagate_rate(clk);
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}
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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 (cpu_is_omap44xx())
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/* OMAP4 clk framework not supported yet */
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return 0;
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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 (clk->usecount == 0) {
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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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if (ret == 0) {
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if (clk->recalc)
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clk->rate = clk->recalc(clk);
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propagate_rate(clk);
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}
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} else
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ret = -EBUSY;
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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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return clk->parent;
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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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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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unsigned long followparent_recalc(struct clk *clk)
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{
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return clk->parent->rate;
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}
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/*
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* Used for clocks that have the same value as the parent clock,
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* divided by some factor
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*/
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unsigned long omap_fixed_divisor_recalc(struct clk *clk)
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{
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WARN_ON(!clk->fixed_div);
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return clk->parent->rate / clk->fixed_div;
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}
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void clk_reparent(struct clk *child, struct clk *parent)
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{
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list_del_init(&child->sibling);
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if (parent)
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list_add(&child->sibling, &parent->children);
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child->parent = parent;
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/* now do the debugfs renaming to reattach the child
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to the proper parent */
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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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list_for_each_entry(clkp, &tclk->children, sibling) {
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if (clkp->recalc)
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clkp->rate = clkp->recalc(clkp);
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propagate_rate(clkp);
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}
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}
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static LIST_HEAD(root_clks);
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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, &root_clks, sibling) {
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if (clkp->recalc)
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clkp->rate = clkp->recalc(clkp);
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propagate_rate(clkp);
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}
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}
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/**
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* clk_preinit - initialize any fields in the struct clk before clk init
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* @clk: struct clk * to initialize
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*
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* Initialize any struct clk fields needed before normal clk initialization
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* can run. No return value.
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*/
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void clk_preinit(struct clk *clk)
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{
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INIT_LIST_HEAD(&clk->children);
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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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/*
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* trap out already registered clocks
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*/
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if (clk->node.next || clk->node.prev)
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return 0;
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mutex_lock(&clocks_mutex);
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if (clk->parent)
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list_add(&clk->sibling, &clk->parent->children);
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else
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list_add(&clk->sibling, &root_clks);
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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->sibling);
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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_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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/*
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* Low level helpers
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*/
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static int clkll_enable_null(struct clk *clk)
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{
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return 0;
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}
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static void clkll_disable_null(struct clk *clk)
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{
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}
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const struct clkops clkops_null = {
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.enable = clkll_enable_null,
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.disable = clkll_disable_null,
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};
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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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void clk_exit_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_exit_cpufreq_table)
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arch_clock->clk_exit_cpufreq_table(table);
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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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#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->ops == &clkops_null)
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continue;
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if (ck->usecount > 0 || 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, *child_tmp;
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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 (!d)
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return -ENOMEM;
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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 (!d) {
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err = -ENOMEM;
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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 (!d) {
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err = -ENOMEM;
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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 (!d) {
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err = -ENOMEM;
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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_safe(child, child_tmp, &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 (!d)
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return -ENOMEM;
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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_recursive(clk_debugfs_root);
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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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