korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-17 07:54:54 +08:00
Code Issues Packages Projects Releases Wiki Activity

ARM: shmobile: sh73a0: wait for completion when kicking the clock

Browse Source 
To reconfigure clocks, controlled by FRQCRA and FRQCRB, a kick bit has to
be set and to make sure the setting has taken effect, it has to be read
back repeatedly until it is cleared by the hardware. This patch adds the
waiting part, that was missing until now.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Magnus Damm <damm@opensource.se
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Guennadi Liakhovetski 2013-02-28 13:21:58 +01:00 committed by Simon Horman
parent d313d068d4
commit 7653c318b7
1 changed files with 17 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
arch/arm/mach-shmobile/clock-sh73a0.c
View File

@ -21,6 +21,7 @@
#include <linux/io.h>
#include <linux/sh_clk.h>
#include <linux/clkdev.h>
#include <asm/processor.h>
#include <mach/common.h>
#define FRQCRA IOMEM(0xe6150000)
@ -234,14 +235,24 @@ static struct clk *main_clks[] = {
&sh73a0_extalr_clk,
};
static int frqcr_kick(void)
{
int i;
/* set KICK bit in FRQCRB to update hardware setting, check success */
__raw_writel(__raw_readl(FRQCRB) | (1 << 31), FRQCRB);
for (i = 1000; i; i--)
if (__raw_readl(FRQCRB) & (1 << 31))
cpu_relax();
else
return i;
return -ETIMEDOUT;
}
static void div4_kick(struct clk *clk)
{
unsigned long value;
/* set KICK bit in FRQCRB to update hardware setting */
value = __raw_readl(FRQCRB);
value |= (1 << 31);
__raw_writel(value, FRQCRB);
frqcr_kick();
}
static int divisors[] = { 2, 3, 4, 6, 8, 12, 16, 18,