drivers/comedi/comedi_buf.c

289 	 * before we write data to the write-alloc'ed buffer space  in _comedi_buf_write_alloc()
297  * comedi_buf_write_alloc() - Reserve buffer space for writing
299  * @nbytes: Maximum space to reserve in bytes.
301  * Reserve up to @nbytes bytes of space to be written in the COMEDI acquisition
303  * by the space available.
305  * Return: The amount of space reserved in bytes.
322  * and kernel space
396  * comedi_buf_write_free() - Free buffer space after it is written
398  * @nbytes: Maximum space to free in bytes.
400  * Free up to @nbytes bytes of space previously reserved for writing in the
402  * space freed is limited to the amount that was reserved.  The freed space is
405  * If the samples in the freed space need to be "munged", do so here.  The
406  * freed space becomes available for allocation by the reader.
408  * Return: The amount of space freed in bytes.
443  * comedi_buf_read_n_available() - Determine amount of readable buffer space
446  * Determine the amount of readable buffer space in the COMEDI acquisition data
447  * buffer associated with the subdevice.  The readable buffer space is that
451  * Return: The amount of readable buffer space.
481 	 * attempt to read data from the read-alloc'ed buffer space  in _comedi_buf_read_alloc()
489  * comedi_buf_read_alloc() - Reserve buffer space for reading
491  * @nbytes: Maximum space to reserve in bytes.
493  * Reserve up to @nbytes bytes of previously written and "munged" buffer space
495  * subdevice.  The amount reserved is limited to the space available.  The
496  * reader can read from the reserved space and then free it.  A reader is also
497  * allowed to read from the space before reserving it as long as it determines
498  * the amount of readable data available, but the space needs to be marked as
501  * Return: The amount of space reserved in bytes.
544  * comedi_buf_read_free() - Free buffer space after it has been read
546  * @nbytes: Maximum space to free in bytes.
548  * Free up to @nbytes bytes of buffer space previously reserved for reading in
550  * amount of space freed is limited to the amount that was reserved.
552  * The freed space becomes available for allocation by the writer.
554  * Return: The amount of space freed in bytes.