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Commit 7cb6580c authored by Axel Lin's avatar Axel Lin Committed by Linus Walleij
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gpio: gpio-pch: Use spinlock for register access protection 



gpio_chip.can_sleep is 0, but current code uses mutex in pch_gpio_set
pch_gpio_get and pch_gpio_direction_input functions.
Thus those functions are not callable from interrupt context.
This patch converts mutex into spinlock.

Signed-off-by: default avatarAxel Lin <axel.lin@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 02a6794d

drivers/gpio/gpio-pch.c

+10 −12
Original line number Diff line number Diff line
@@ -92,9 +92,7 @@ struct pch_gpio_reg_data { 
 * @lock:			Used for register access protection

 * @irq_base:		Save base of IRQ number for interrupt

 * @ioh:		IOH ID

 * @spinlock:		Used for register access protection in

 *				interrupt context pch_irq_mask,

 *				pch_irq_unmask and pch_irq_type;

 * @spinlock:		Used for register access protection

 */

struct pch_gpio {

	void __iomem *base;
@@ -102,7 +100,6 @@ struct pch_gpio { 
	struct device *dev;

	struct gpio_chip gpio;

	struct pch_gpio_reg_data pch_gpio_reg;

	struct mutex lock;

	int irq_base;

	enum pch_type_t ioh;

	spinlock_t spinlock;
@@ -112,8 +109,9 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) 
{

	u32 reg_val;

	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	reg_val = ioread32(&chip->reg->po);

	if (val)

		reg_val |= (1 << nr);
@@ -121,7 +119,7 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) 
		reg_val &= ~(1 << nr);



	iowrite32(reg_val, &chip->reg->po);

	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);

}



static int pch_gpio_get(struct gpio_chip *gpio, unsigned nr)
@@ -137,8 +135,9 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, 
	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);

	u32 pm;

	u32 reg_val;

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1);

	pm |= (1 << nr);

	iowrite32(pm, &chip->reg->pm);
@@ -149,8 +148,7 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, 
	else

		reg_val &= ~(1 << nr);

	iowrite32(reg_val, &chip->reg->po);



	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);



	return 0;

}
@@ -159,12 +157,13 @@ static int pch_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) 
{

	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);

	u32 pm;

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1);

	pm &= ~(1 << nr);

	iowrite32(pm, &chip->reg->pm);

	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);



	return 0;

}
@@ -387,7 +386,6 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev, 


	chip->reg = chip->base;

	pci_set_drvdata(pdev, chip);

	mutex_init(&chip->lock);

	spin_lock_init(&chip->spinlock);

	pch_gpio_setup(chip);

	ret = gpiochip_add(&chip->gpio);