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authorBaruch Siach <baruch@tkos.co.il>2010-07-06 14:03:22 +0300
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 11:09:13 -0700
commit2812c8f70ec3a6c5abd0305a42366c880a18a85a (patch)
tree237162792983c2b0b0612b2845b7c879a9339efc
parent01212f0b3d3f13d263cf157128f836496b78b113 (diff)
downloadlinux-2.6.34-ux500-2812c8f70ec3a6c5abd0305a42366c880a18a85a.tar.gz
arm/imx/gpio: add spinlock protection
commit 14cb0deb66fcfca8fdbef75da8c84b5405a8c767 upstream. The GPIO registers need protection from concurrent access for operations that are not atomic. Cc: Juergen Beisert <j.beisert@pengutronix.de> Cc: Daniel Mack <daniel@caiaq.de> Reported-by: rpkamiak@rockwellcollins.com Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/arm/plat-mxc/gpio.c8
-rw-r--r--arch/arm/plat-mxc/include/mach/gpio.h1
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/gpio.c b/arch/arm/plat-mxc/gpio.c
index 71437c61cfd..9ebbd31fe03 100644
--- a/arch/arm/plat-mxc/gpio.c
+++ b/arch/arm/plat-mxc/gpio.c
@@ -214,13 +214,16 @@ static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
struct mxc_gpio_port *port =
container_of(chip, struct mxc_gpio_port, chip);
u32 l;
+ unsigned long flags;
+ spin_lock_irqsave(&port->lock, flags);
l = __raw_readl(port->base + GPIO_GDIR);
if (dir)
l |= 1 << offset;
else
l &= ~(1 << offset);
__raw_writel(l, port->base + GPIO_GDIR);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
@@ -229,9 +232,12 @@ static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
container_of(chip, struct mxc_gpio_port, chip);
void __iomem *reg = port->base + GPIO_DR;
u32 l;
+ unsigned long flags;
+ spin_lock_irqsave(&port->lock, flags);
l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
__raw_writel(l, reg);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
@@ -285,6 +291,8 @@ int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt)
port[i].chip.base = i * 32;
port[i].chip.ngpio = 32;
+ spin_lock_init(&port[i].lock);
+
/* its a serious configuration bug when it fails */
BUG_ON( gpiochip_add(&port[i].chip) < 0 );
diff --git a/arch/arm/plat-mxc/include/mach/gpio.h b/arch/arm/plat-mxc/include/mach/gpio.h
index 894d2f87c85..6bd932c3e4e 100644
--- a/arch/arm/plat-mxc/include/mach/gpio.h
+++ b/arch/arm/plat-mxc/include/mach/gpio.h
@@ -36,6 +36,7 @@ struct mxc_gpio_port {
int virtual_irq_start;
struct gpio_chip chip;
u32 both_edges;
+ spinlock_t lock;
};
int mxc_gpio_init(struct mxc_gpio_port*, int);