redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

ARM: mxs: select HAVE_CLK_PREPARE for clock 

This patch adds clk_prepare/clk_unprepare for mxs clock api by
renaming the existing non-atomic clk_enable/clk_disable to
clk_prepare/clk_unprepare and adding a pair of dummy
clk_enable/clk_disable.  Then with selecting HAVE_CLK_PREPARE for
mxs clock, we can fix the mutex locking warning that has been
reported for a few times.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
hifive-unleashed-5.1
Shawn Guo 2011-12-20 16:12:34 +08:00
parent 5c77f5608a
commit 6abda3e129
2 changed files with 23 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/Kconfig
View File

@ -442,6 +442,7 @@ config ARCH_MXS
select ARCH_REQUIRE_GPIOLIB
select CLKDEV_LOOKUP
select CLKSRC_MMIO
select HAVE_CLK_PREPARE
help
Support for Freescale MXS-based family of processors

31
arch/arm/mach-mxs/clock.c
View File

@ -74,10 +74,15 @@ static int __clk_enable(struct clk *clk)
return 0;
}
/* This function increments the reference count on the clock and enables the
* clock if not already enabled. The parent clock tree is recursively enabled
/*
* The clk_enable/clk_disable could be called by drivers in atomic context,
* so they should not really hold mutex. Instead, clk_prepare/clk_unprepare
* can hold a mutex, as the pair will only be called in non-atomic context.
* Before migrating to common clk framework, we can have __clk_enable and
* __clk_disable called in clk_prepare/clk_unprepare with mutex held and
* leave clk_enable/clk_disable as the dummy functions.
*/
int clk_enable(struct clk *clk)
int clk_prepare(struct clk *clk)
{
int ret = 0;
@ -90,13 +95,9 @@ int clk_enable(struct clk *clk)
return ret;
}
EXPORT_SYMBOL(clk_enable);
EXPORT_SYMBOL(clk_prepare);
/* This function decrements the reference count on the clock and disables
* the clock when reference count is 0. The parent clock tree is
* recursively disabled
*/
void clk_disable(struct clk *clk)
void clk_unprepare(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return;
@ -105,6 +106,18 @@ void clk_disable(struct clk *clk)
__clk_disable(clk);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unprepare);
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
/* nothing to do */
}
EXPORT_SYMBOL(clk_disable);
/* Retrieve the *current* clock rate. If the clock itself