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ramips: protect GPIO register access with a spinlock

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SVN-Revision: 22171
This commit is contained in:
Gabor Juhos 2010-07-13 16:52:04 +00:00
parent 9ee8b1f8c6
commit 27375c5139
1 changed files with 11 additions and 1 deletions
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12
target/linux/ramips/files/arch/mips/ralink/common/gpio.c
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@ -10,7 +10,7 @@
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/gpio.h>
#include <ralink_soc.h>
@ -64,6 +64,7 @@ enum ramips_pio_reg {
struct ramips_gpio_chip {
struct gpio_chip chip;
spinlock_t lock;
u8 regs[RAMIPS_GPIO_REG_MAX];
};
@ -90,11 +91,14 @@ static inline u32 ramips_gpio_rr(struct ramips_gpio_chip *rg, u8 reg)
static int ramips_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct ramips_gpio_chip *rg = to_ramips_gpio(chip);
unsigned long flags;
u32 t;
spin_lock_irqsave(&rg->lock, flags);
t = ramips_gpio_rr(rg, RAMIPS_GPIO_REG_DIR);
t &= ~(1 << offset);
ramips_gpio_wr(rg, RAMIPS_GPIO_REG_DIR, t);
spin_unlock_irqrestore(&rg->lock, flags);
return 0;
}
@ -103,15 +107,19 @@ static int ramips_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct ramips_gpio_chip *rg = to_ramips_gpio(chip);
unsigned long flags;
u32 reg;
u32 t;
reg = (value) ? RAMIPS_GPIO_REG_SET : RAMIPS_GPIO_REG_RESET;
spin_lock_irqsave(&rg->lock, flags);
ramips_gpio_wr(rg, reg, 1 << offset);
t = ramips_gpio_rr(rg, RAMIPS_GPIO_REG_DIR);
t |= 1 << offset;
ramips_gpio_wr(rg, RAMIPS_GPIO_REG_DIR, t);
spin_unlock_irqrestore(&rg->lock, flags);
return 0;
}
@ -208,6 +216,8 @@ static struct ramips_gpio_chip ramips_gpio_chip2 = {
static __init void ramips_gpio_chip_add(struct ramips_gpio_chip *rg)
{
spin_lock_init(&rg->lock);
/* set polarity to low for all lines */
ramips_gpio_wr(rg, RAMIPS_GPIO_REG_POL, 0);