staging: comedi: pcmmio: tidy up the multi-line comments

/*

    comedi/drivers/pcmmio.c

    Driver for Winsystems PC-104 based multifunction IO board.

    COMEDI - Linux Control and Measurement Device Interface

    Copyright (C) 2007 Calin A. Culianu <calin@ajvar.org>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

 * pcmmio.c

 * Driver for Winsystems PC-104 based multifunction IO board.

 *

 * COMEDI - Linux Control and Measurement Device Interface

 * Copyright (C) 2007 Calin A. Culianu <calin@ajvar.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

/*

Driver: pcmmio

Description: A driver for the PCM-MIO multifunction board

Devices: [Winsystems] PCM-MIO (pcmmio)

Author: Calin Culianu <calin@ajvar.org>

Updated: Wed, May 16 2007 16:21:10 -0500

Status: works

A driver for the relatively new PCM-MIO multifunction board from

Winsystems.  This board is a PC-104 based I/O board.  It contains

four subdevices:

  subdevice 0 - 16 channels of 16-bit AI

  subdevice 1 - 8 channels of 16-bit AO

  subdevice 2 - first 24 channels of the 48 channel of DIO

	(with edge-triggered interrupt support)

  subdevice 3 - last 24 channels of the 48 channel DIO

	(no interrupt support for this bank of channels)

  Some notes:

  Synchronous reads and writes are the only things implemented for AI and AO,

  even though the hardware itself can do streaming acquisition, etc.  Anyone

  want to add asynchronous I/O for AI/AO as a feature?  Be my guest...

  Asynchronous I/O for the DIO subdevices *is* implemented, however!  They are

  basically edge-triggered interrupts for any configuration of the first

  24 DIO-lines.

  Also note that this interrupt support is untested.

  A few words about edge-detection IRQ support (commands on DIO):

/*

 * Driver: pcmmio

 * Description: A driver for the PCM-MIO multifunction board

 * Devices: (Winsystems) PCM-MIO [pcmmio]

 * Author: Calin Culianu <calin@ajvar.org>

 * Updated: Wed, May 16 2007 16:21:10 -0500

 * Status: works

 *

 * A driver for the PCM-MIO multifunction board from Winsystems. This

 * is a PC-104 based I/O board. It contains four subdevices:

 *

 *	subdevice 0 - 16 channels of 16-bit AI

 *	subdevice 1 - 8 channels of 16-bit AO

 *	subdevice 2 - first 24 channels of the 48 channel of DIO

 *			(with edge-triggered interrupt support)

 *	subdevice 3 - last 24 channels of the 48 channel DIO

 *			(no interrupt support for this bank of channels)

 *

 * Some notes:

 *

 * Synchronous reads and writes are the only things implemented for analog

 * input and output. The hardware itself can do streaming acquisition, etc.

 *

 * Asynchronous I/O for the DIO subdevices *is* implemented, however! They

 * are basically edge-triggered interrupts for any configuration of the

 * channels in subdevice 2.

 *

 * Also note that this interrupt support is untested.

 *

 * A few words about edge-detection IRQ support (commands on DIO):

 *

 * To use edge-detection IRQ support for the DIO subdevice, pass the IRQ

    of the board to the comedi_config command.  The board IRQ is not jumpered

    but rather configured through software, so any IRQ from 1-15 is OK.

 * of the board to the comedi_config command. The board IRQ is not jumpered

 * but rather configured through software, so any IRQ from 1-15 is OK.

 *

 * Due to the genericity of the comedi API, you need to create a special

    comedi_command in order to use edge-triggered interrupts for DIO.

 * comedi_command in order to use edge-triggered interrupts for DIO.

 *

 * Use comedi_commands with TRIG_NOW.  Your callback will be called each

    time an edge is detected on the specified DIO line(s), and the data

    values will be two sample_t's, which should be concatenated to form

    one 32-bit unsigned int.  This value is the mask of channels that had

    edges detected from your channel list.  Note that the bits positions

    in the mask correspond to positions in your chanlist when you

    specified the command and *not* channel id's!

 * time an edge is detected on the specified DIO line(s), and the data

 * values will be two sample_t's, which should be concatenated to form

 * one 32-bit unsigned int. This value is the mask of channels that had

 * edges detected from your channel list. Note that the bits positions

 * in the mask correspond to positions in your chanlist when you

 * specified the command and *not* channel id's!

 *

 * To set the polarity of the edge-detection interrupts pass a nonzero value

    for either CR_RANGE or CR_AREF for edge-up polarity, or a zero

    value for both CR_RANGE and CR_AREF if you want edge-down polarity.

Configuration Options:

  [0] - I/O port base address

  [1] - IRQ (optional -- for edge-detect interrupt support only,

	leave out if you don't need this feature)

 * for either CR_RANGE or CR_AREF for edge-up polarity, or a zero

 * value for both CR_RANGE and CR_AREF if you want edge-down polarity.

 *

 * Configuration Options:

 *   [0] - I/O port base address

 *   [1] - IRQ (optional -- for edge-detect interrupt support only,

 *		leave out if you don't need this feature)

 */

#include <linux/module.h>