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Commit 02a6794d authored by Axel Lin's avatar Axel Lin Committed by Linus Walleij
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gpio: gpio-ml-ioh: Use spinlock for register access protection 



gpio_chip.can_sleep is 0, but current code uses mutex in ioh_gpio_set,
ioh_gpio_get and ioh_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 f9c4a31f

drivers/gpio/gpio-ml-ioh.c

+10 −10
Original line number Diff line number Diff line
@@ -87,8 +87,7 @@ struct ioh_gpio_reg_data { 
 * @gpio_use_sel:		Save GPIO_USE_SEL1~4 register for PM

 * @ch:				Indicate GPIO channel

 * @irq_base:		Save base of IRQ number for interrupt

 * @spinlock:		Used for register access protection in

 *				interrupt context ioh_irq_type and PM;

 * @spinlock:		Used for register access protection

 */

struct ioh_gpio {

	void __iomem *base;
@@ -97,7 +96,6 @@ struct ioh_gpio { 
	struct gpio_chip gpio;

	struct ioh_gpio_reg_data ioh_gpio_reg;

	u32 gpio_use_sel;

	struct mutex lock;

	int ch;

	int irq_base;

	spinlock_t spinlock;
@@ -109,8 +107,9 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) 
{

	u32 reg_val;

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

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	reg_val = ioread32(&chip->reg->regs[chip->ch].po);

	if (val)

		reg_val |= (1 << nr);
@@ -118,7 +117,7 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) 
		reg_val &= ~(1 << nr);



	iowrite32(reg_val, &chip->reg->regs[chip->ch].po);

	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);

}



static int ioh_gpio_get(struct gpio_chip *gpio, unsigned nr)
@@ -134,8 +133,9 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, 
	struct ioh_gpio *chip =	container_of(gpio, struct ioh_gpio, gpio);

	u32 pm;

	u32 reg_val;

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	pm = ioread32(&chip->reg->regs[chip->ch].pm) &

					((1 << num_ports[chip->ch]) - 1);

	pm |= (1 << nr);
@@ -148,7 +148,7 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, 
		reg_val &= ~(1 << nr);

	iowrite32(reg_val, &chip->reg->regs[chip->ch].po);



	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);



	return 0;

}
@@ -157,13 +157,14 @@ static int ioh_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) 
{

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

	u32 pm;

	unsigned long flags;



	mutex_lock(&chip->lock);

	spin_lock_irqsave(&chip->spinlock, flags);

	pm = ioread32(&chip->reg->regs[chip->ch].pm) &

				((1 << num_ports[chip->ch]) - 1);

	pm &= ~(1 << nr);

	iowrite32(pm, &chip->reg->regs[chip->ch].pm);

	mutex_unlock(&chip->lock);

	spin_unlock_irqrestore(&chip->spinlock, flags);



	return 0;

}
@@ -447,7 +448,6 @@ static int __devinit ioh_gpio_probe(struct pci_dev *pdev, 
		chip->base = base;

		chip->reg = chip->base;

		chip->ch = i;

		mutex_init(&chip->lock);

		spin_lock_init(&chip->spinlock);

		ioh_gpio_setup(chip, num_ports[i]);

		ret = gpiochip_add(&chip->gpio);