linux相关gpio函数

/home/ysy/linux/IMX6ULL/linux/linux-imx-rel_imx_4.1.15_2.1.0_ga/include/linux/gpio.h

static inline int gpio_direction_output(unsigned gpio, int value)
{
	return -ENOSYS;
}

/home/ysy/linux/IMX6ULL/linux/linux-imx-rel_imx_4.1.15_2.1.0_ga/include/asm-generic/gpio.h
static inline int gpio_direction_output(unsigned gpio, int value)
{
	return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
}

/home/ysy/linux/IMX6ULL/linux/linux-imx-rel_imx_4.1.15_2.1.0_ga/include/linux/gpio/consumer.h

static inline int gpiod_get_direction(const struct gpio_desc *desc)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
	return -ENOSYS;
}
static inline int gpiod_direction_input(struct gpio_desc *desc)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
	return -ENOSYS;
}
static inline int gpiod_direction_output(struct gpio_desc *desc, int value)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
	return -ENOSYS;
}
static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
	return -ENOSYS;
}


static inline int gpiod_get_value(const struct gpio_desc *desc)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
	return 0;
}
static inline void gpiod_set_value(struct gpio_desc *desc, int value)
{
	/* GPIO can never have been requested */
	WARN_ON(1);
}

/home/ysy/linux/IMX6ULL/linux/linux-imx-rel_imx_4.1.15_2.1.0_ga/include/linux/of_gpio.h

enum of_gpio_flags {
	OF_GPIO_ACTIVE_LOW = 0x1,
};

static inline int of_gpio_named_count(struct device_node *np, const char* propname)
{
	return of_count_phandle_with_args(np, propname, "#gpio-cells");
}

/**
 * of_gpio_count() - Count GPIOs for a device
 * @np:		device node to count GPIOs for
 *
 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 */
static inline int of_gpio_count(struct device_node *np)
{
	return of_gpio_named_count(np, "gpios");
}

static inline int of_get_gpio_flags(struct device_node *np, int index,
		      enum of_gpio_flags *flags)
{
	return of_get_named_gpio_flags(np, "gpios", index, flags);
}

/**
 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 * @np:		device node to get GPIO from
 * @propname:	Name of property containing gpio specifier(s)
 * @index:	index of the GPIO
 *
 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 * value on the error condition.
 */
static inline int of_get_named_gpio(struct device_node *np,
                                   const char *propname, int index)
{
	return of_get_named_gpio_flags(np, propname, index, NULL);
}

/**
 * of_get_gpio() - Get a GPIO number to use with GPIO API
 * @np:		device node to get GPIO from
 * @index:	index of the GPIO
 *
 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 * value on the error condition.
 */
static inline int of_get_gpio(struct device_node *np, int index)
{
	return of_get_gpio_flags(np, index, NULL);
}



/home/ysy/linux/IMX6ULL/linux/linux-imx-rel_imx_4.1.15_2.1.0_ga/drivers/gpio/gpiolib-of.c

int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
			    int index, enum of_gpio_flags *flags)
{
	struct gpio_desc *desc;

	desc = of_get_named_gpiod_flags(np, list_name, index, flags);

	if (IS_ERR(desc))
		return PTR_ERR(desc);
	else
		return desc_to_gpio(desc);
}
EXPORT_SYMBOL(of_get_named_gpio_flags);

int platform_get_irq(struct platform_device *dev, unsigned int num)
{
#ifdef CONFIG_SPARC
	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
	if (!dev || num >= dev->archdata.num_irqs)
		return -ENXIO;
	return dev->archdata.irqs[num];
#else
	struct resource *r;
	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
		int ret;

		ret = of_irq_get(dev->dev.of_node, num);
		if (ret >= 0 || ret == -EPROBE_DEFER)
			return ret;
	}

	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
	/*
	 * The resources may pass trigger flags to the irqs that need
	 * to be set up. It so happens that the trigger flags for
	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
	 * settings.
	 */
	if (r && r->flags & IORESOURCE_BITS)
		irqd_set_trigger_type(irq_get_irq_data(r->start),
				      r->flags & IORESOURCE_BITS);

	return r ? r->start : -ENXIO;
#endif
}
EXPORT_SYMBOL_GPL(platform_get_irq);