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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 10:20:37 -0700
commit96f6b7b0a8d82d9016ecf241aa78c2c264b77412 (patch)
tree1524ddd96be2f686ee7fb83b84bb8ed74f92edc3 /arch
parent250fac9f6418d573e8031ad0ad0028585034e80d (diff)
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>
Diffstat (limited to 'arch')
-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 cfc4a8b43e6..c47aa88cc83 100644
--- a/arch/arm/plat-mxc/gpio.c
+++ b/arch/arm/plat-mxc/gpio.c
@@ -223,13 +223,16 @@ 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)
@@ -238,9 +241,12 @@ 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)
@@ -294,6 +300,8 @@ 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);