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ARM: S5P6440: Add locking to GPIO calls 

Add the new locking calls to ensure that these are always exclusively
accessing the GPIO registers.

Fixes a possible race between two threads modifying the same GPIO bank,

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Ben Dooks 2010-05-19 16:31:49 +09:00
parent 1ae35de1c1
commit 6a39954724
1 changed files with 15 additions and 0 deletions
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15
arch/arm/mach-s5p6440/gpio.c
View File

@ -46,6 +46,7 @@ static int s5p6440_gpiolib_rbank_4bit2_input(struct gpio_chip *chip,
void __iomem *base = ourchip->base;
void __iomem *regcon = base;
unsigned long con;
unsigned long flags;
switch (offset) {
case 6:
@ -63,10 +64,14 @@ static int s5p6440_gpiolib_rbank_4bit2_input(struct gpio_chip *chip,
break;
}
s3c_gpio_lock(ourchip, flags);
con = __raw_readl(regcon);
con &= ~(0xf << con_4bit_shift(offset));
__raw_writel(con, regcon);
s3c_gpio_unlock(ourchip, flags);
return 0;
}
@ -78,6 +83,7 @@ static int s5p6440_gpiolib_rbank_4bit2_output(struct gpio_chip *chip,
void __iomem *regcon = base;
unsigned long con;
unsigned long dat;
unsigned long flags;
unsigned con_offset = offset;
switch (con_offset) {
@ -96,6 +102,8 @@ static int s5p6440_gpiolib_rbank_4bit2_output(struct gpio_chip *chip,
break;
}
s3c_gpio_lock(ourchip, flags);
con = __raw_readl(regcon);
con &= ~(0xf << con_4bit_shift(con_offset));
con |= 0x1 << con_4bit_shift(con_offset);
@ -109,6 +117,8 @@ static int s5p6440_gpiolib_rbank_4bit2_output(struct gpio_chip *chip,
__raw_writel(con, regcon);
__raw_writel(dat, base + GPIODAT_OFF);
s3c_gpio_unlock(ourchip, flags);
return 0;
}
@ -117,6 +127,7 @@ int s5p6440_gpio_setcfg_4bit_rbank(struct s3c_gpio_chip *chip,
{
void __iomem *reg = chip->base;
unsigned int shift;
unsigned long flags;
u32 con;
switch (off) {
@ -142,11 +153,15 @@ int s5p6440_gpio_setcfg_4bit_rbank(struct s3c_gpio_chip *chip,
cfg <<= shift;
}
s3c_gpio_lock(chip, flags);
con = __raw_readl(reg);
con &= ~(0xf << shift);
con |= cfg;
__raw_writel(con, reg);
s3c_gpio_unlock(chip, flags);
return 0;
}