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>

diff --git a/arch/arm/mach-s5p6440/gpio.c b/arch/arm/mach-s5p6440/gpio.c
index 262dc75..92efc05 100644 (file)
--- a/arch/arm/mach-s5p6440/gpio.c
+++ b/arch/arm/mach-s5p6440/gpio.c
@@ -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;
 }