diff options
author | Ben Dooks <ben-linux@fluff.org> | 2006-02-08 21:09:05 (GMT) |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-02-08 21:09:05 (GMT) |
commit | 2a513ce79958d47b72a11c76ec291c8c1169214c (patch) | |
tree | 2698cdc04f710d80da77ed36f6e3aad6d5e9fa57 /arch | |
parent | f8e5b28413a8bf0b421dd116b30ab2d3befec629 (diff) | |
download | linux-fsl-qoriq-2a513ce79958d47b72a11c76ec291c8c1169214c.tar.xz |
[ARM] 3303/1: S3C24XX - add clock enable usage counting
Patch from Ben Dooks
Move to using an enable count for the shared clocks
and protect the clock system using a mutex instead
of just disabling IRQs during the clock update.
Since there is little more code in the path for
non-shared clocks, the enable and disable calls
use the same code for each.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/mach-s3c2410/clock.c | 43 | ||||
-rw-r--r-- | arch/arm/mach-s3c2410/clock.h | 1 |
2 files changed, 34 insertions, 10 deletions
diff --git a/arch/arm/mach-s3c2410/clock.c b/arch/arm/mach-s3c2410/clock.c index af2f3d5..08489ef 100644 --- a/arch/arm/mach-s3c2410/clock.c +++ b/arch/arm/mach-s3c2410/clock.c @@ -40,7 +40,6 @@ #include <linux/mutex.h> #include <asm/hardware.h> -#include <asm/atomic.h> #include <asm/irq.h> #include <asm/io.h> @@ -59,22 +58,18 @@ static DEFINE_MUTEX(clocks_mutex); void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable) { unsigned long clkcon; - unsigned long flags; - - local_irq_save(flags); clkcon = __raw_readl(S3C2410_CLKCON); - clkcon &= ~clocks; if (enable) clkcon |= clocks; + else + clkcon &= ~clocks; /* ensure none of the special function bits set */ clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER); __raw_writel(clkcon, S3C2410_CLKCON); - - local_irq_restore(flags); } /* enable and disable calls for use with the clk struct */ @@ -138,16 +133,32 @@ void clk_put(struct clk *clk) int clk_enable(struct clk *clk) { - if (IS_ERR(clk)) + if (IS_ERR(clk) || clk == NULL) return -EINVAL; - return (clk->enable)(clk, 1); + clk_enable(clk->parent); + + mutex_lock(&clocks_mutex); + + if ((clk->usage++) == 0) + (clk->enable)(clk, 1); + + mutex_unlock(&clocks_mutex); + return 0; } void clk_disable(struct clk *clk) { - if (!IS_ERR(clk)) + if (IS_ERR(clk) || clk == NULL) + return; + + mutex_lock(&clocks_mutex); + + if ((--clk->usage) == 0) (clk->enable)(clk, 0); + + mutex_unlock(&clocks_mutex); + clk_disable(clk->parent); } @@ -361,6 +372,14 @@ int s3c24xx_register_clock(struct clk *clk) if (clk->enable == NULL) clk->enable = clk_null_enable; + /* if this is a standard clock, set the usage state */ + + if (clk->ctrlbit) { + unsigned long clkcon = __raw_readl(S3C2410_CLKCON); + + clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0; + } + /* add to the list of available clocks */ mutex_lock(&clocks_mutex); @@ -402,6 +421,8 @@ int __init s3c24xx_setup_clocks(unsigned long xtal, * the LCD clock if it is not needed. */ + mutex_lock(&clocks_mutex); + s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0); s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0); s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0); @@ -409,6 +430,8 @@ int __init s3c24xx_setup_clocks(unsigned long xtal, s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0); s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0); + mutex_unlock(&clocks_mutex); + /* assume uart clocks are correctly setup */ /* register our clocks */ diff --git a/arch/arm/mach-s3c2410/clock.h b/arch/arm/mach-s3c2410/clock.h index 177d5c8..eb5c95d 100644 --- a/arch/arm/mach-s3c2410/clock.h +++ b/arch/arm/mach-s3c2410/clock.h @@ -16,6 +16,7 @@ struct clk { struct clk *parent; const char *name; int id; + int usage; unsigned long rate; unsigned long ctrlbit; int (*enable)(struct clk *, int enable); |