Commit 08f81bf1 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: pcl730: clean up the register map documentation 



This driver supports a number of simple digital i/o boards with
slight variations in the register map. Clean up the comment about
the register map to better document the driver.

Remove the #define's used for the registers since thet don't apply
to all the board variations supported by the driver.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ef5838d9

drivers/staging/comedi/drivers/pcl730.c

+43 −17
Original line number Diff line number Diff line
@@ -32,19 +32,46 @@ 
#include <linux/ioport.h>



/*

 * Register I/O map

 * Register map

 *

 * The pcm3730 PC/104 board does not have the PCL730_IDIO_HI register.

 * The pcl725 ISA board uses separate registers for isolated digital I/O.

 * The p8r8dio, acl7225b, and p16r16dio boards have isolated digital output

 * readback and separate registers for isolated digital I/O.

 * The pcl733 ISA board uses all four registers for isolated digital inputs.

 * The pcl734 ISA board uses all four registers for isolated digital outputs.

 * The register map varies slightly depending on the board type but

 * all registers are 8-bit.

 *

 * The boardinfo 'io_range' is used to allow comedi to request the

 * proper range required by the board.

 *

 * The comedi_subdevice 'private' data is used to pass the register

 * offset to the (*insn_bits) functions to read/write the correct

 * registers.

 *

 * The basic register mapping looks like this:

 *

 *     BASE+0  Isolated outputs 0-7 (write) / inputs 0-7 (read)

 *     BASE+1  Isolated outputs 8-15 (write) / inputs 8-15 (read)

 *     BASE+2  TTL outputs 0-7 (write) / inputs 0-7 (read)

 *     BASE+3  TTL outputs 8-15 (write) / inputs 8-15 (read)

 *

 * The pcm3730 board does not have register BASE+1.

 *

 * The pcl725 and p8r8dio only have registers BASE+0 and BASE+1:

 *

 *     BASE+0  Isolated outputs 0-7 (write) (read back on p8r8dio)

 *     BASE+1  Isolated inputs 0-7 (read)

 *

 * The acl7225b and p16r16dio boards have this register mapping:

 *

 *     BASE+0  Isolated outputs 0-7 (write) (read back)

 *     BASE+1  Isolated outputs 8-15 (write) (read back)

 *     BASE+2  Isolated inputs 0-7 (read)

 *     BASE+3  Isolated inputs 8-15 (read)

 *

 * The pcl733 and pcl733 boards have this register mapping:

 *

 *     BASE+0  Isolated outputs 0-7 (write) or inputs 0-7 (read)

 *     BASE+1  Isolated outputs 8-15 (write) or inputs 8-15 (read)

 *     BASE+2  Isolated outputs 16-23 (write) or inputs 16-23 (read)

 *     BASE+3  Isolated outputs 24-31 (write) or inputs 24-31 (read)

 */

#define PCL730_IDIO_LO	0	/* Isolated Digital I/O low byte (ID0-ID7) */

#define PCL730_IDIO_HI	1	/* Isolated Digital I/O high byte (ID8-ID15) */

#define PCL730_DIO_LO	2	/* TTL Digital I/O low byte (D0-D7) */

#define PCL730_DIO_HI	3	/* TTL Digital I/O high byte (D8-D15) */



struct pcl730_board {

	const char *name;
@@ -217,7 +244,7 @@ static int pcl730_attach(struct comedi_device *dev, 
		s->maxdata	= 1;

		s->range_table	= &range_digital;

		s->insn_bits	= pcl730_do_insn_bits;

		s->private	= (void *)PCL730_IDIO_LO;

		s->private	= (void *)0;



		/* get the initial state if supported */

		if (board->has_readback)
@@ -233,9 +260,8 @@ static int pcl730_attach(struct comedi_device *dev, 
		s->maxdata	= 1;

		s->range_table	= &range_digital;

		s->insn_bits	= pcl730_di_insn_bits;

		s->private	= board->is_acl7225b ? (void *)PCL730_DIO_LO :

				  board->is_pcl725 ? (void *)PCL730_IDIO_HI

						   : (void *)PCL730_IDIO_LO;

		s->private	= board->is_acl7225b ? (void *)2 :

				  board->is_pcl725 ? (void *)1 : (void *)0;

	}



	if (board->has_ttl_io) {
@@ -247,7 +273,7 @@ static int pcl730_attach(struct comedi_device *dev, 
		s->maxdata	= 1;

		s->range_table	= &range_digital;

		s->insn_bits	= pcl730_do_insn_bits;

		s->private	= (void *)PCL730_DIO_LO;

		s->private	= (void *)2;



		/* TTL Digital Inputs */

		s = &dev->subdevices[subdev++];
@@ -257,7 +283,7 @@ static int pcl730_attach(struct comedi_device *dev, 
		s->maxdata	= 1;

		s->range_table	= &range_digital;

		s->insn_bits	= pcl730_di_insn_bits;

		s->private	= (void *)PCL730_DIO_LO;

		s->private	= (void *)2;

	}



	return 0;