linux/arch/m68k/coldfire/clk.c
Dan Carpenter f6a4f0b424 m68k: coldfire: return success for clk_enable(NULL)
The clk_enable is supposed work when CONFIG_HAVE_CLK is false, but it
returns -EINVAL.  That means some drivers fail during probe.

[    1.680000] flexcan: probe of flexcan.0 failed with error -22

Fixes: c1fb1bf64b ("m68k: let clk_enable() return immediately if clk is NULL")
Fixes: bea8bcb12d ("m68knommu: Add support for the Coldfire m5441x.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2021-08-23 08:40:04 +10:00

145 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/***************************************************************************/
/*
* 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 */
int clk_enable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return 0;
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);
unsigned long clk_get_rate(struct clk *clk)
{
if (!clk)
return 0;
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
/* dummy functions, should not be called */
long clk_round_rate(struct clk *clk, unsigned long rate)
{
WARN_ON(clk);
return 0;
}
EXPORT_SYMBOL(clk_round_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
WARN_ON(clk);
return 0;
}
EXPORT_SYMBOL(clk_set_rate);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
WARN_ON(clk);
return 0;
}
EXPORT_SYMBOL(clk_set_parent);
struct clk *clk_get_parent(struct clk *clk)
{
WARN_ON(clk);
return NULL;
}
EXPORT_SYMBOL(clk_get_parent);
/***************************************************************************/