line flag check result wrong in chardev version

[xlla]

I have init a line, and set direction to output successful. later, when I check this line's direction by call function mraa_gpio_read_dir, it will think "Line used by kernel." and return ERROR.

in function mraa_gpio_read_dir, it will check line->flags with those macro

#define GPIOLINE_FLAG_KERNEL        (1UL << 0) /* Line used by the kernel */
#define GPIOLINE_FLAG_IS_OUT        (1UL << 1)
#define GPIOLINE_FLAG_ACTIVE_LOW    (1UL << 2)
#define GPIOLINE_FLAG_OPEN_DRAIN    (1UL << 3)
#define GPIOLINE_FLAG_OPEN_SOURCE   (1UL << 4)

but in mraa_gpio_chardev_dir function, it set line->flag with those macro

/* Linerequest flags */
#define GPIOHANDLE_REQUEST_INPUT    (1UL << 0)
#define GPIOHANDLE_REQUEST_OUTPUT   (1UL << 1)
#define GPIOHANDLE_REQUEST_ACTIVE_LOW   (1UL << 2)
#define GPIOHANDLE_REQUEST_OPEN_DRAIN   (1UL << 3)
#define GPIOHANDLE_REQUEST_OPEN_SOURCE  (1UL << 4)

if I skip mraa_gpio_read_dir and check direction, just call mraa_gpio_write in this line, it will success, and program runs fine.

is this function right? it will stop init in function mraa_intel_edison_fab_c statement

if (mraa_gpio_read_dir(tristate, &tristate_dir) != MRAA_SUCCESS) {

[Propanu]

is this function right? it will stop init in function mraa_intel_edison_fab_c statement

Hi @xlla, yes the function is right but only needed with the Arduino expansion board which is now a retired product. That pin needs to be set to MRAA_GPIO_OUT to successfully init the SPI bus and ADC.

[xlla]

Hi @Propanu , I am understand it's purpose,
the issus is in chardev version,
I have init a line by

tristate = mraa_gpio_init_by_name(TRI_STATE_ALL)

and set the direction by

mraa_gpio_dir(tristate, MRAA_GPIO_OUT)

then I check the direction by

 mraa_gpio_read_dir(tristate, &tristate_dir)

it will wrong and report "Line used by kernel".