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diff --git a/c-user/io/directives.rst b/c-user/io/directives.rst new file mode 100644 index 0000000..d3098cb --- /dev/null +++ b/c-user/io/directives.rst @@ -0,0 +1,421 @@ +.. SPDX-License-Identifier: CC-BY-SA-4.0 + +.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR) + +Directives +========== + +This section details the I/O manager's directives. A subsection is dedicated +to each of this manager's directives and describes the calling sequence, +related constants, usage, and status codes. + +.. raw:: latex + + \clearpage + +.. index:: register a device driver +.. index:: rtems_io_register_driver + +.. _rtems_io_register_driver: + +IO_REGISTER_DRIVER - Register a device driver +--------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_register_driver( + rtems_device_major_number major, + rtems_driver_address_table *driver_table, + rtems_device_major_number *registered_major + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully registered + * - ``RTEMS_INVALID_ADDRESS`` + - invalid registered major pointer + * - ``RTEMS_INVALID_ADDRESS`` + - invalid driver table + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + * - ``RTEMS_TOO_MANY`` + - no available major device table slot + * - ``RTEMS_RESOURCE_IN_USE`` + - major device number entry in use + +DESCRIPTION: + This directive attempts to add a new device driver to the Device Driver + Table. The user can specify a specific major device number via the + directive's ``major`` parameter, or let the registration routine find the + next available major device number by specifing a major number of + ``0``. The selected major device number is returned via the + ``registered_major`` directive parameter. The directive automatically + allocation major device numbers from the highest value down. + + This directive automatically invokes the ``IO_INITIALIZE`` directive if the + driver address table has an initialization and open entry. + + The directive returns ``RTEMS_TOO_MANY`` if Device Driver Table is full, + and ``RTEMS_RESOURCE_IN_USE`` if a specific major device number is + requested and it is already in use. + +NOTES: + The Device Driver Table size is specified in the Configuration Table + condiguration. This needs to be set to maximum size the application + requires. + +.. raw:: latex + + \clearpage + +.. index:: unregister a device driver +.. index:: rtems_io_unregister_driver + +.. _rtems_io_unregister_driver: + +IO_UNREGISTER_DRIVER - Unregister a device driver +------------------------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_unregister_driver( + rtems_device_major_number major + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully registered + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive removes a device driver from the Device Driver Table. + +NOTES: + Currently no specific checks are made and the driver is not closed. + +.. raw:: latex + + \clearpage + +.. index:: initialize a device driver +.. index:: rtems_io_initialize + +.. _rtems_io_initialize: + +IO_INITIALIZE - Initialize a device driver +------------------------------------------ + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver initialization routine specified in + the Device Driver Table for this major number. This directive is + automatically invoked for each device driver when multitasking is initiated + via the initialize_executive directive. + + A device driver initialization module is responsible for initializing all + hardware and data structures associated with a device. If necessary, it can + allocate memory to be used during other operations. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being initialized. + +.. raw:: latex + + \clearpage + +.. index:: register device +.. index:: rtems_io_register_name + +.. _rtems_io_register_name: + +IO_REGISTER_NAME - Register a device +------------------------------------ + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_register_name( + const char *name, + rtems_device_major_number major, + rtems_device_minor_number minor + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_TOO_MANY`` + - too many devices registered + +DESCRIPTION: + This directive associates name with the specified major/minor number pair. + +NOTES: + This directive will not cause the calling task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: lookup device major and minor number +.. index:: rtems_io_lookup_name + +.. _rtems_io_lookup_name: + +IO_LOOKUP_NAME - Lookup a device +-------------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_lookup_name( + const char *name, + rtems_driver_name_t *device_info + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_UNSATISFIED`` + - name not registered + +DESCRIPTION: + This directive returns the major/minor number pair associated with the + given device name in ``device_info``. + +NOTES: + This directive will not cause the calling task to be preempted. + +.. raw:: latex + + \clearpage + +.. index:: open a devive +.. index:: rtems_io_open + +.. _rtems_io_open: + +IO_OPEN - Open a device +----------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_open( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver open routine specified in the Device + Driver Table for this major number. The open entry point is commonly used + by device drivers to provide exclusive access to a device. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being invoked. + +.. raw:: latex + + \clearpage + +.. index:: close a device +.. index:: rtems_io_close + +.. _rtems_io_close: + +IO_CLOSE - Close a device +------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_close( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver close routine specified in the + Device Driver Table for this major number. The close entry point is + commonly used by device drivers to relinquish exclusive access to a device. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being invoked. + +.. raw:: latex + + \clearpage + +.. index:: read from a device +.. index:: rtems_io_read + +.. _rtems_io_read: + +IO_READ - Read from a device +---------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_read( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver read routine specified in the Device + Driver Table for this major number. Read operations typically require a + buffer address as part of the argument parameter block. The contents of + this buffer will be replaced with data from the device. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being invoked. + +.. raw:: latex + + \clearpage + +.. index:: write to a device +.. index:: rtems_io_write + +.. _rtems_io_write: + +IO_WRITE - Write to a device +---------------------------- + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_write( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver write routine specified in the + Device Driver Table for this major number. Write operations typically + require a buffer address as part of the argument parameter block. The + contents of this buffer will be sent to the device. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being invoked. + +.. raw:: latex + + \clearpage + +.. index:: special device services +.. index:: IO Control +.. index:: rtems_io_control + +.. _rtems_io_control: + +IO_CONTROL - Special device services +------------------------------------ + +CALLING SEQUENCE: + .. code-block:: c + + rtems_status_code rtems_io_control( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *argument + ); + +DIRECTIVE STATUS CODES: + .. list-table:: + :class: rtems-table + + * - ``RTEMS_SUCCESSFUL`` + - successfully initialized + * - ``RTEMS_INVALID_NUMBER`` + - invalid major device number + +DESCRIPTION: + This directive calls the device driver I/O control routine specified in the + Device Driver Table for this major number. The exact functionality of the + driver entry called by this directive is driver dependent. It should not + be assumed that the control entries of two device drivers are compatible. + For example, an RS-232 driver I/O control operation may change the baud + rate of a serial line, while an I/O control operation for a floppy disk + driver may cause a seek operation. + +NOTES: + This directive may or may not cause the calling task to be preempted. This + is dependent on the device driver being invoked. |