s3c2410-GPIO操作相关系列函数解析
函数的定义在arch/arm/mach-s3c2410/gpio.c,相关的宏定义在include/asm-arm/arch-s3c2410/regs-gpio.h
(1)voids3c2410_gpio_setpin(unsigned int pin, unsigned intto);
设置相应GPIO口的输出值,例如:
pin=S3C2410_GPG2,to=0,则设置S3C2410_GPG2的输出值为0;
pin=S3C2410_GPG2,to=1,则设置S3C2410_GPG2的输出值为1。
函数定义:
-
void
s3c2410_gpio_setpin(unsigned intpin, intunsigned to) -
{
-
void __iomem *base = S3C2410_GPIO_BASE(pin); -
unsigned long offs = S3C2410_GPIO_OFFSET(pin); -
unsigned long flags; -
unsigned long dat; -
-
local_irq_save(flags); -
-
dat = __raw_readl(base + 0x04); -
dat &= ~(1 << offs); -
dat |= to << offs; -
__raw_writel(dat, base + 0x04); -
-
local_irq_restore(flags); -
}
-
EXPORT_SYMBOL(s3c2410_gpio_setpin);
(2)unsigned int s3c2410_gpio_getpin(unsigned intpin);
获取相应GPIO口的值。
函数定义:
-
unsigned
int s3c2410_gpio_getpin(unsigned intpin) -
{
-
void __iomem *base = S3C2410_GPIO_BASE(pin); -
unsigned long offs = S3C2410_GPIO_OFFSET(pin); -
-
return __raw_readl(base + 0x04) & (1<< offs); -
}
-
-
EXPORT_SYMBOL(s3c2410_gpio_getpin);
(3)voids3c2410_gpio_cfgpin(unsigned int pin, unsigned intfunction);
设置相应GPIO口的工作模式,输入、输出、中断等。
函数定义:
-
void
s3c2410_gpio_cfgpin(unsigned intpin, intunsigned function) -
{
-
void __iomem *base = S3C2410_GPIO_BASE(pin); -
unsigned long mask; -
unsigned long con; -
unsigned long flags; -
-
if (pin < S3C2410_GPIO_BANKB) { -
mask = 1 << S3C2410_GPIO_OFFSET(pin); -
} else { -
mask = 3 << S3C2410_GPIO_OFFSET(pin)*2; -
} -
-
local_irq_save(flags); -
-
con = __raw_readl(base + 0x00); -
con &= ~mask; -
con |= function; -
-
__raw_writel(con, base + 0x00); -
-
local_irq_restore(flags); -
}
-
-
EXPORT_SYMBOL(s3c2410_gpio_cfgpin);
(4)unsignedint s3c2410_gpio_getcfg(unsigned int pin);
获取相应GPIO口的工作模式,输入、输出、中断等。
函数定义:
-
unsigned
int s3c2410_gpio_getcfg(unsigned intpin) -
{
-
void __iomem *base = S3C2410_GPIO_BASE(pin); -
unsigned long mask; -
-
if (pin < S3C2410_GPIO_BANKB) { -
mask = 1 << S3C2410_GPIO_OFFSET(pin); -
} else { -
mask = 3 << S3C2410_GPIO_OFFSET(pin)*2; -
} -