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![Defang Bo](/assets/img/avatar_default.png)
Similar to commit<742859adc721>("m68k: let clk_disable() return immediately if clk is NULL"). there should be a check for clk to prevent NULL pointer dereference. Signed-off-by: Defang Bo <bodefang@126.com> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
165 lines
3.3 KiB
C
165 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/***************************************************************************/
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/*
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* clk.c -- general ColdFire CPU kernel clk handling
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*
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* Copyright (C) 2009, Greg Ungerer (gerg@snapgear.com)
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*/
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/***************************************************************************/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/err.h>
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#include <asm/coldfire.h>
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#include <asm/mcfsim.h>
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#include <asm/mcfclk.h>
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static DEFINE_SPINLOCK(clk_lock);
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#ifdef MCFPM_PPMCR0
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/*
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* For more advanced ColdFire parts that have clocks that can be enabled
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* we supply enable/disable functions. These must properly define their
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* clocks in their platform specific code.
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*/
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void __clk_init_enabled(struct clk *clk)
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{
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clk->enabled = 1;
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clk->clk_ops->enable(clk);
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}
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void __clk_init_disabled(struct clk *clk)
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{
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clk->enabled = 0;
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clk->clk_ops->disable(clk);
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}
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static void __clk_enable0(struct clk *clk)
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{
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__raw_writeb(clk->slot, MCFPM_PPMCR0);
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}
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static void __clk_disable0(struct clk *clk)
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{
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__raw_writeb(clk->slot, MCFPM_PPMSR0);
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}
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struct clk_ops clk_ops0 = {
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.enable = __clk_enable0,
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.disable = __clk_disable0,
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};
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#ifdef MCFPM_PPMCR1
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static void __clk_enable1(struct clk *clk)
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{
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__raw_writeb(clk->slot, MCFPM_PPMCR1);
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}
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static void __clk_disable1(struct clk *clk)
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{
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__raw_writeb(clk->slot, MCFPM_PPMSR1);
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}
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struct clk_ops clk_ops1 = {
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.enable = __clk_enable1,
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.disable = __clk_disable1,
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};
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#endif /* MCFPM_PPMCR1 */
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#endif /* MCFPM_PPMCR0 */
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struct clk *clk_get(struct device *dev, const char *id)
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{
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const char *clk_name = dev ? dev_name(dev) : id ? id : NULL;
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struct clk *clk;
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unsigned i;
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for (i = 0; (clk = mcf_clks[i]) != NULL; ++i)
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if (!strcmp(clk->name, clk_name))
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return clk;
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pr_warn("clk_get: didn't find clock %s\n", clk_name);
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return ERR_PTR(-ENOENT);
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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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if (!clk)
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return -EINVAL;
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spin_lock_irqsave(&clk_lock, flags);
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if ((clk->enabled++ == 0) && clk->clk_ops)
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clk->clk_ops->enable(clk);
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spin_unlock_irqrestore(&clk_lock, flags);
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return 0;
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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)
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return;
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spin_lock_irqsave(&clk_lock, flags);
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if ((--clk->enabled == 0) && clk->clk_ops)
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clk->clk_ops->disable(clk);
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spin_unlock_irqrestore(&clk_lock, flags);
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}
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EXPORT_SYMBOL(clk_disable);
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void clk_put(struct clk *clk)
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{
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if (clk->enabled != 0)
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pr_warn("clk_put %s still enabled\n", clk->name);
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}
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EXPORT_SYMBOL(clk_put);
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unsigned long clk_get_rate(struct clk *clk)
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{
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if (!clk)
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return 0;
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return clk->rate;
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}
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EXPORT_SYMBOL(clk_get_rate);
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/* dummy functions, should not be called */
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long clk_round_rate(struct clk *clk, unsigned long rate)
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{
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WARN_ON(clk);
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return 0;
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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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WARN_ON(clk);
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return 0;
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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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WARN_ON(clk);
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return 0;
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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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WARN_ON(clk);
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return NULL;
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}
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EXPORT_SYMBOL(clk_get_parent);
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/***************************************************************************/
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