From 2a513ce79958d47b72a11c76ec291c8c1169214c Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Wed, 8 Feb 2006 21:09:05 +0000 Subject: [PATCH] [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 Signed-off-by: Russell King --- arch/arm/mach-s3c2410/clock.c | 43 +++++++++++++++++++++++++++-------- 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 af2f3d52b61b..08489efdaf06 100644 --- a/arch/arm/mach-s3c2410/clock.c +++ b/arch/arm/mach-s3c2410/clock.c @@ -40,7 +40,6 @@ #include #include -#include #include #include @@ -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 177d5c8decf7..eb5c95d1e7f2 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); -- GitLab