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authorGabor Juhos <juhosg@openwrt.org>2010-07-13 16:52:04 +0000
committerGabor Juhos <juhosg@openwrt.org>2010-07-13 16:52:04 +0000
commit27375c513937c315c55340d9b35ed61942171630 (patch)
treef0ff9b150a0985c93bacb128342f425850154db9
parent9ee8b1f8c6d82ceef4493809355e5b0306312836 (diff)
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mtk-20170518-27375c513937c315c55340d9b35ed61942171630.tar.gz
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ramips: protect GPIO register access with a spinlock
SVN-Revision: 22171
-rw-r--r--target/linux/ramips/files/arch/mips/ralink/common/gpio.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/target/linux/ramips/files/arch/mips/ralink/common/gpio.c b/target/linux/ramips/files/arch/mips/ralink/common/gpio.c
index 892f15b..e350fc1 100644
--- a/target/linux/ramips/files/arch/mips/ralink/common/gpio.c
+++ b/target/linux/ramips/files/arch/mips/ralink/common/gpio.c
@@ -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);