linux_dsm_epyc7002/arch/m68k/coldfire/clk.c
Masahiro Yamada 742859adc7 m68k: let clk_disable() return immediately if clk is NULL
In many of clk_disable() implementations, it is a no-op for a NULL
pointer input, but this is one of the exceptions.

Making it treewide consistent will allow clock consumers to call
clk_disable() without NULL pointer check.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-09-26 12:02:59 +10:00

129 lines
2.7 KiB
C

/***************************************************************************/
/*
* clk.c -- general ColdFire CPU kernel clk handling
*
* Copyright (C) 2009, Greg Ungerer (gerg@snapgear.com)
*/
/***************************************************************************/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfclk.h>
static DEFINE_SPINLOCK(clk_lock);
#ifdef MCFPM_PPMCR0
/*
* For more advanced ColdFire parts that have clocks that can be enabled
* we supply enable/disable functions. These must properly define their
* clocks in their platform specific code.
*/
void __clk_init_enabled(struct clk *clk)
{
clk->enabled = 1;
clk->clk_ops->enable(clk);
}
void __clk_init_disabled(struct clk *clk)
{
clk->enabled = 0;
clk->clk_ops->disable(clk);
}
static void __clk_enable0(struct clk *clk)
{
__raw_writeb(clk->slot, MCFPM_PPMCR0);
}
static void __clk_disable0(struct clk *clk)
{
__raw_writeb(clk->slot, MCFPM_PPMSR0);
}
struct clk_ops clk_ops0 = {
.enable = __clk_enable0,
.disable = __clk_disable0,
};
#ifdef MCFPM_PPMCR1
static void __clk_enable1(struct clk *clk)
{
__raw_writeb(clk->slot, MCFPM_PPMCR1);
}
static void __clk_disable1(struct clk *clk)
{
__raw_writeb(clk->slot, MCFPM_PPMSR1);
}
struct clk_ops clk_ops1 = {
.enable = __clk_enable1,
.disable = __clk_disable1,
};
#endif /* MCFPM_PPMCR1 */
#endif /* MCFPM_PPMCR0 */
struct clk *clk_get(struct device *dev, const char *id)
{
const char *clk_name = dev ? dev_name(dev) : id ? id : NULL;
struct clk *clk;
unsigned i;
for (i = 0; (clk = mcf_clks[i]) != NULL; ++i)
if (!strcmp(clk->name, clk_name))
return clk;
pr_warn("clk_get: didn't find clock %s\n", clk_name);
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
if ((clk->enabled++ == 0) && clk->clk_ops)
clk->clk_ops->enable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return;
spin_lock_irqsave(&clk_lock, flags);
if ((--clk->enabled == 0) && clk->clk_ops)
clk->clk_ops->disable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
void clk_put(struct clk *clk)
{
if (clk->enabled != 0)
pr_warn("clk_put %s still enabled\n", clk->name);
}
EXPORT_SYMBOL(clk_put);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
/***************************************************************************/