Peripheral_Descriptor_t FreeRTOS_open( const int8_t *pcPath, const uint32_t ulFlags );
Opens a peripheral for use with FreeRTOS+IO. The board support package defines which peripherals are available on any particular platform.
Parameters:
| pcPath |
The text name of the peripheral
being opened, as defined by the board support package.
|
| ulFlags | Mode flags. This parameter is not currently used. It is included for two reasons - so the FreeRTOS_open() prototype complies with the standard open() prototype, and to ensure backward compatibility after future FreeRTOS+IO developments. |
NULL if the peripheral could not be opened, otherwise a variable of type Peripheral_Descriptor_t that can be used to access the opened peripheral in future calls to FreeRTOS_read(), FreeRTOS_write() and FreeRTOS_ioctl().
Example usage:
/* FreeRTOS+IO includes. */ #include "FreeRTOS_IO.h" void vAFunction( void ) { /* The Peripheral_Descriptor_t type is the FreeRTOS+IO equivalent of a descriptor. */ Peripheral_Descriptor_t xOpenedPort; /* Open the SPI port identified in the board support package as using the path string "/SPI2/". The second parameter is not currently used and can be set to anything, although, for future compatibility, it is recommended that it is set to NULL. */ xOpenedPort = FreeRTOS_open( "/SPI2/", NULL ); if( xOpenedPort != NULL ) { /* xOpenedPort now contains a valid descriptor that can be used with other FreeRTOS+IO API functions. */ . . . } else { /* The port was not opened successfully. */ } } FreeRTOS_open() example