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Commit b27b6d03 authored by Cyril Chemparathy's avatar Cyril Chemparathy Committed by Kevin Hilman
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Davinci: gpio - fine grained locking 



This patch eliminates the global gpio_lock, and implements a per-controller
lock instead.  This also switches to irqsave/irqrestore locks in case gpios
are manipulated in isr.

Signed-off-by: default avatarCyril Chemparathy <cyril@ti.com>
Tested-by: default avatarSandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
parent 686b634a

arch/arm/mach-davinci/gpio.c

+5 −4
Original line number Diff line number Diff line
@@ -33,8 +33,6 @@ struct davinci_gpio_regs { 
	u32	intstat;

};



static DEFINE_SPINLOCK(gpio_lock);



#define chip2controller(chip)	\

	container_of(chip, struct davinci_gpio_controller, chip)
@@ -83,10 +81,11 @@ static inline int __davinci_direction(struct gpio_chip *chip, 
{

	struct davinci_gpio_controller *d = chip2controller(chip);

	struct davinci_gpio_regs __iomem *g = d->regs;

	unsigned long flags;

	u32 temp;

	u32 mask = 1 << offset;



	spin_lock(&gpio_lock);

	spin_lock_irqsave(&d->lock, flags);

	temp = __raw_readl(&g->dir);

	if (out) {

		temp &= ~mask;
@@ -95,7 +94,7 @@ static inline int __davinci_direction(struct gpio_chip *chip, 
		temp |= mask;

	}

	__raw_writel(temp, &g->dir);

	spin_unlock(&gpio_lock);

	spin_unlock_irqrestore(&d->lock, flags);



	return 0;

}
@@ -175,6 +174,8 @@ static int __init davinci_gpio_setup(void) 
		if (chips[i].chip.ngpio > 32)

			chips[i].chip.ngpio = 32;



		spin_lock_init(&chips[i].lock);



		regs = gpio2regs(base);

		chips[i].regs = regs;

		chips[i].set_data = &regs->set_data;

arch/arm/mach-davinci/include/mach/gpio.h

+3 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
#define	__DAVINCI_GPIO_H



#include <linux/io.h>

#include <linux/spinlock.h>



#include <asm-generic/gpio.h>



#include <mach/irqs.h>
@@ -52,6 +54,7 @@ enum davinci_gpio_type { 
struct davinci_gpio_controller {

	struct gpio_chip	chip;

	int			irq_base;

	spinlock_t		lock;

	void __iomem		*regs;

	void __iomem		*set_data;

	void __iomem		*clr_data;