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Commit 14cb0deb authored by Baruch Siach's avatar Baruch Siach Committed by Sascha Hauer
Browse files

arm/imx/gpio: add spinlock protection 



The GPIO registers need protection from concurrent access for operations that
are not atomic.

Cc: stable@kernel.org
Cc: Juergen Beisert <j.beisert@pengutronix.de>
Cc: Daniel Mack <daniel@caiaq.de>
Reported-by: default avatar <rpkamiak@rockwellcollins.com>
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent ef93f144

arch/arm/plat-mxc/gpio.c

+8 −0
Original line number Diff line number Diff line
@@ -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 );

arch/arm/plat-mxc/include/mach/gpio.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 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);