About calling kernel functions in the driver to implement gpio register settings

Series Function

The functions are defined in arch/arm/mach-s3c2410/gpio.c, and the related macros are defined in include/asm-arm/arch-s3c2410/regs-gpio.h

(1) void s3c2410_gpio_setpin(unsigned int pin, unsigned intto);

Set the output value of the corresponding GPIO port, for example:

pin=S3C2410_GPG2, to=0, then set the output value of S3C2410_GPG2 to 0;

pin=S3C2410_GPG2, to=1, then set the output value of S3C2410_GPG2 to 1.

Function definition:

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void s3c2410_gpio_setpin(unsigned int pin, unsigned int 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);

Get the value of the corresponding GPIO port.

Function definition:

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unsigned int s3c2410_gpio_getpin(unsigned int pin)  

{  

    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) void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function);

Set the working mode of the corresponding GPIO port, input, output, interrupt, etc.

Function definition:

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void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int 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) unsigned int s3c2410_gpio_getcfg(unsigned intpin);

Get the working mode of the corresponding GPIO port, including input, output, interrupt, etc.

Function definition:

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unsigned int s3c2410_gpio_getcfg(unsigned int pin)  

{  

    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;  

    }  

    return __raw_readl(base) & mask;  

}  

EXPORT_SYMBOL(s3c2410_gpio_getcfg);  

(5) voids3c2410_gpio_pullup(unsigned int pin, unsigned intto);

Set the level of the corresponding GPIO port, for example:

pin=S3C2410_GPG2, to=0, then pull down S3C2410_GPG2, that is, set the value of S3C2410_GPG2 to 0;

pin=S3C2410_GPG2, to=1, then pull up S3C2410_GPG2, that is, set the value of S3C2410_GPG2 to 1.

Function definition:

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void s3c2410_gpio_pullup(unsigned int pin, unsigned int to)  

{  

    void __iomem *base = S3C2410_GPIO_BASE(pin);  

    unsigned long offs = S3C2410_GPIO_OFFSET(pin);  

    unsigned long flags;  

    unsigned long up;  

    if (pin < S3C2410_GPIO_BANKB)  

        return;  

    local_irq_save(flags);  

    up = __raw_readl(base + 0x08);  

    up &= ~(1L << offs);  

    up |= to << offs;  

    __raw_writel(up, base + 0x08);  

    local_irq_restore(flags);  

}  

EXPORT_SYMBOL(s3c2410_gpio_pullup);  

(6) unsigned int s3c2410_modify_misccr(unsigned int clear,unsigned int change);

Miscellaneous settings, set register MISCCR, see the function definition for details.

Function definition:

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unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change)  

{  

    unsigned long flags;  

    unsigned long misccr;  

    local_irq_save(flags);  

    misccr = __raw_readl(S3C2410_MISCCR);  

    misccr &= ~clear;  

    misccr ^= change;  

    __raw_writel(misccr, S3C2410_MISCCR);  

    local_irq_restore(flags);  

    return misccr;  

}  

EXPORT_SYMBOL(s3c2410_modify_misccr);  

(7) int s3c2410_gpio_getirq(unsigned intpin);

Get the interrupt number corresponding to the corresponding GPIO port.

Function definition:

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int s3c2410_gpio_getirq(unsigned int pin)  

{  

    if (pin < S3C2410_GPF0 || pin > S3C2410_GPG15_EINT23)  

        return -1;   

    if (pin < S3C2410_GPG0 && pin > S3C2410_GPF7)  

        return -1;   

    if (pin < S3C2410_GPF4)  

        return (pin - S3C2410_GPF0) + IRQ_EINT0;  

    if (pin < S3C2410_GPG0)  

        return (pin - S3C2410_GPF4) + IRQ_EINT4;  

    return (pin - S3C2410_GPG0) + IRQ_EINT8;  

}  

EXPORT_SYMBOL(s3c2410_gpio_getirq);  

(8) int s3c2410_gpio_irqfilter(unsigned int pin, unsigned int on, unsigned int config);

Interrupt filter configuration, see the function definition for details.

Function definition:

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int s3c2410_gpio_irqfilter(unsigned int pin, unsigned int on,  

               unsigned int config)  

{  

    void __iomem *reg = S3C2410_EINFLT0;  

    unsigned long flags;  

    unsigned long val;  

    if (pin < S3C2410_GPG8 || pin > S3C2410_GPG15)  

        return -1;  

    config &= 0xff;  

    pin -= S3C2410_GPG8_EINT16;  

    reg += pin & ~3;  

    local_irq_save(flags);  

    val = __raw_readl(reg);  

    val &= ~(0xff << ((pin & 3) * 8));  

    val |= config << ((pin & 3) * 8);  

    __raw_writel(val, reg);  

    val = __raw_readl(S3C2410_EXTINT2);  

    val &= ~(1 << ((pin * 4) + 3));  

    val |= on << ((pin * 4) + 3);  

    __raw_writel(val, S3C2410_EXTINT2);  

    local_irq_restore(flags);  

    return 0;  

}  

EXPORT_SYMBOL(s3c2410_gpio_irqfilter);