gpio-admin.c

Defines

GPIO_CLASS_PATH

GPIO_EXPORT_PATH

GPIO_UNEXPORT_PATH

DOWN

UP

BLOCK_SIZE

GPIO_BASE

GPPUD

GPPUDCLK0

BIT(x)

BANK(x)

Functions

static void usage_error(char **argv)

Prints a help message in case of wrongful invocation

Parameters

• argv -

  The array of arguments (only argv[0] is used)

static void allow_access_by_user(unsigned int pin, const char *filename)

Sets the ownership of a pin

Parameters

• pin -

  The number of the pin

• filename -

  The filename

static unsigned int parse_gpio_pin(const char *pin_str)

Checks the input and returns the value of the pin

Return

An integer with the value of the pin

Parameters

• pin_str -

  the number of the pin in a string

static void write_pin_to_path(const char *path, unsigned int pin)

Writes the pin value in the desired path

Parameters

• path -

  The path of the file to write

• pin -

  The number of the pin

static void set_pullupdown(int pin, int direction)

Sets the direction of the pin

Parameters

• pin -

  The value of the pin

• direction -

  The direction (0 for out, 1 for in)

int main(int argc, char **argv)

Parses the console parameters and executes the desired action.

Parameters

• argc -

  The number of console parameters

• argv -

  The value of the console parameters