linux/arch/arm/mach-w90x900/clock.c
Masahiro Yamada e1ffaa551c ARM: w90x900: 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>
Acked-by: Wan Zongshun <mcuos.com@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2017-03-30 17:37:19 +02:00

96 lines
1.8 KiB
C

/*
* linux/arch/arm/mach-w90x900/clock.c
*
* Copyright (c) 2008 Nuvoton technology corporation
*
* Wan ZongShun <mcuos.com@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include "clock.h"
#define SUBCLK 0x24
static DEFINE_SPINLOCK(clocks_lock);
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clocks_lock, flags);
if (clk->enabled++ == 0)
(clk->enable)(clk, 1);
spin_unlock_irqrestore(&clocks_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return;
WARN_ON(clk->enabled == 0);
spin_lock_irqsave(&clocks_lock, flags);
if (--clk->enabled == 0)
(clk->enable)(clk, 0);
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return 15000000;
}
EXPORT_SYMBOL(clk_get_rate);
void nuc900_clk_enable(struct clk *clk, int enable)
{
unsigned int clocks = clk->cken;
unsigned long clken;
clken = __raw_readl(W90X900_VA_CLKPWR);
if (enable)
clken |= clocks;
else
clken &= ~clocks;
__raw_writel(clken, W90X900_VA_CLKPWR);
}
void nuc900_subclk_enable(struct clk *clk, int enable)
{
unsigned int clocks = clk->cken;
unsigned long clken;
clken = __raw_readl(W90X900_VA_CLKPWR + SUBCLK);
if (enable)
clken |= clocks;
else
clken &= ~clocks;
__raw_writel(clken, W90X900_VA_CLKPWR + SUBCLK);
}