Staging: comedi: add das16 driver

Driver for DAS16 compatible boards

From: David Schleef <ds@schleef.org>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1730 insertions, 0 deletions

diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c
new file mode 100644
index 00000000000..42a81b832a9
--- /dev/null
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -0,0 +1,1730 @@
+/*
+    comedi/drivers/das16.c
+    DAS16 driver
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+    Copyright (C) 2000 Chris R. Baugher <baugher@enteract.com>
+    Copyright (C) 2001,2002 Frank Mori Hess <fmhess@users.sourceforge.net>
+
+    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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+************************************************************************
+*/
+/*
+Driver: das16
+Description: DAS16 compatible boards
+Author: Sam Moore, Warren Jasper, ds, Chris Baugher, Frank Hess, Roman Fietze
+Devices: [Keithley Metrabyte] DAS-16 (das-16), DAS-16G (das-16g),
+  DAS-16F (das-16f), DAS-1201 (das-1201), DAS-1202 (das-1202),
+  DAS-1401 (das-1401), DAS-1402 (das-1402), DAS-1601 (das-1601),
+  DAS-1602 (das-1602),
+  [ComputerBoards] PC104-DAS16/JR (pc104-das16jr),
+  PC104-DAS16JR/16 (pc104-das16jr/16),
+  CIO-DAS16JR/16 (cio-das16jr/16),
+  CIO-DAS16/JR (cio-das16/jr), CIO-DAS1401/12 (cio-das1401/12),
+  CIO-DAS1402/12 (cio-das1402/12), CIO-DAS1402/16 (cio-das1402/16),
+  CIO-DAS1601/12 (cio-das1601/12), CIO-DAS1602/12 (cio-das1602/12),
+  CIO-DAS1602/16 (cio-das1602/16), CIO-DAS16/330 (cio-das16/330)
+Status: works
+Updated: 2003-10-12
+
+A rewrite of the das16 and das1600 drivers.
+Options:
+	[0] - base io address
+	[1] - irq (does nothing, irq is not used anymore)
+	[2] - dma (optional, required for comedi_command support)
+	[3] - master clock speed in MHz (optional, 1 or 10, ignored if
+		board can probe clock, defaults to 1)
+	[4] - analog input range lowest voltage in microvolts (optional,
+		only useful if your board does not have software
+		programmable gain)
+	[5] - analog input range highest voltage in microvolts (optional,
+		only useful if board does not have software programmable
+		gain)
+	[6] - analog output range lowest voltage in microvolts (optional)
+	[7] - analog output range highest voltage in microvolts (optional)
+	[8] - use timer mode for DMA.  Timer mode is needed e.g. for
+		buggy DMA controllers in NS CS5530A (Geode Companion), and for
+		'jr' cards that lack a hardware fifo.  This option is no
+		longer needed, since timer mode is _always_ used.
+
+Passing a zero for an option is the same as leaving it unspecified.
+
+*/
+/*
+
+Testing and debugging help provided by Daniel Koch.
+
+Keithley Manuals:
+	2309.PDF (das16)
+	4919.PDF (das1400, 1600)
+	4922.PDF (das-1400)
+	4923.PDF (das1200, 1400, 1600)
+
+Computer boards manuals also available from their website www.measurementcomputing.com
+
+*/
+
+#include <linux/pci.h>
+#include <asm/dma.h>
+#include "../comedidev.h"
+
+#include "8253.h"
+#include "8255.h"
+#include "comedi_fc.h"
+
+#undef DEBUG
+//#define DEBUG
+
+#ifdef DEBUG
+#define DEBUG_PRINT(format, args...) rt_printk("das16: " format, ## args)
+#else
+#define DEBUG_PRINT(format, args...)
+#endif
+
+#define DAS16_SIZE 20		// number of ioports
+#define DAS16_DMA_SIZE 0xff00	// size in bytes of allocated dma buffer
+
+/*
+    cio-das16.pdf
+
+    "das16"
+    "das16/f"
+
+  0	a/d bits 0-3		start 12 bit
+  1	a/d bits 4-11		unused
+  2	mux read		mux set
+  3	di 4 bit		do 4 bit
+  4	unused			ao0_lsb
+  5	unused			ao0_msb
+  6	unused			ao1_lsb
+  7	unused			ao1_msb
+  8	status eoc uni/bip	interrupt reset
+  9	dma, int, trig ctrl	set dma, int
+  a	pacer control		unused
+  b	reserved		reserved
+  cdef	8254
+  0123	8255
+
+*/
+
+/*
+    cio-das16jr.pdf
+
+    "das16jr"
+
+  0	a/d bits 0-3		start 12 bit
+  1	a/d bits 4-11		unused
+  2	mux read		mux set
+  3	di 4 bit		do 4 bit
+  4567	unused			unused
+  8	status eoc uni/bip	interrupt reset
+  9	dma, int, trig ctrl	set dma, int
+  a	pacer control		unused
+  b	gain status		gain control
+  cdef	8254
+
+*/
+
+/*
+    cio-das16jr_16.pdf
+
+    "das16jr_16"
+
+  0	a/d bits 0-7		start 16 bit
+  1	a/d bits 8-15		unused
+  2	mux read		mux set
+  3	di 4 bit		do 4 bit
+  4567	unused			unused
+  8	status eoc uni/bip	interrupt reset
+  9	dma, int, trig ctrl	set dma, int
+  a	pacer control		unused
+  b	gain status		gain control
+  cdef	8254
+
+*/
+/*
+    cio-das160x-1x.pdf
+
+    "das1601/12"
+    "das1602/12"
+    "das1602/16"
+
+  0	a/d bits 0-3		start 12 bit
+  1	a/d bits 4-11		unused
+  2	mux read		mux set
+  3	di 4 bit		do 4 bit
+  4	unused			ao0_lsb
+  5	unused			ao0_msb
+  6	unused			ao1_lsb
+  7	unused			ao1_msb
+  8	status eoc uni/bip	interrupt reset
+  9	dma, int, trig ctrl	set dma, int
+  a	pacer control		unused
+  b	gain status		gain control
+  cdef	8254
+  400	8255
+  404	unused			conversion enable
+  405	unused			burst enable
+  406	unused			das1600 enable
+  407	status
+
+*/
+
+static const int sample_size = 2;	// size in bytes of a sample from board
+
+#define DAS16_TRIG		0
+#define DAS16_AI_LSB		0
+#define DAS16_AI_MSB		1
+#define DAS16_MUX		2
+#define DAS16_DIO		3
+#define DAS16_AO_LSB(x)	((x)?6:4)
+#define DAS16_AO_MSB(x)	((x)?7:5)
+#define DAS16_STATUS		8
+#define   BUSY			(1<<7)
+#define   UNIPOLAR			(1<<6)
+#define   DAS16_MUXBIT			(1<<5)
+#define   DAS16_INT			(1<<4)
+#define DAS16_CONTROL		9
+#define   DAS16_INTE			(1<<7)
+#define   DAS16_IRQ(x)			(((x) & 0x7) << 4)
+#define   DMA_ENABLE			(1<<2)
+#define   PACING_MASK	0x3
+#define   INT_PACER		0x03
+#define   EXT_PACER			0x02
+#define   DAS16_SOFT		0x00
+#define DAS16_PACER		0x0A
+#define   DAS16_CTR0			(1<<1)
+#define   DAS16_TRIG0			(1<<0)
+#define   BURST_LEN_BITS(x)			(((x) & 0xf) << 4)
+#define DAS16_GAIN		0x0B
+#define DAS16_CNTR0_DATA		0x0C
+#define DAS16_CNTR1_DATA		0x0D
+#define DAS16_CNTR2_DATA		0x0E
+#define DAS16_CNTR_CONTROL	0x0F
+#define   DAS16_TERM_CNT	0x00
+#define   DAS16_ONE_SHOT	0x02
+#define   DAS16_RATE_GEN	0x04
+#define   DAS16_CNTR_LSB_MSB	0x30
+#define   DAS16_CNTR0		0x00
+#define   DAS16_CNTR1		0x40
+#define   DAS16_CNTR2		0x80
+
+#define DAS1600_CONV		0x404
+#define   DAS1600_CONV_DISABLE		0x40
+#define DAS1600_BURST		0x405
+#define   DAS1600_BURST_VAL		0x40
+#define DAS1600_ENABLE		0x406
+#define   DAS1600_ENABLE_VAL		0x40
+#define DAS1600_STATUS_B	0x407
+#define   DAS1600_BME		0x40
+#define   DAS1600_ME		0x20
+#define   DAS1600_CD			0x10
+#define   DAS1600_WS			0x02
+#define   DAS1600_CLK_10MHZ		0x01
+
+static const comedi_lrange range_das1x01_bip = { 4, {
+			BIP_RANGE(10),
+			BIP_RANGE(1),
+			BIP_RANGE(0.1),
+			BIP_RANGE(0.01),
+	}
+};
+static const comedi_lrange range_das1x01_unip = { 4, {
+			UNI_RANGE(10),
+			UNI_RANGE(1),
+			UNI_RANGE(0.1),
+			UNI_RANGE(0.01),
+	}
+};
+static const comedi_lrange range_das1x02_bip = { 4, {
+			BIP_RANGE(10),
+			BIP_RANGE(5),
+			BIP_RANGE(2.5),
+			BIP_RANGE(1.25),
+	}
+};
+static const comedi_lrange range_das1x02_unip = { 4, {
+			UNI_RANGE(10),
+			UNI_RANGE(5),
+			UNI_RANGE(2.5),
+			UNI_RANGE(1.25),
+	}
+};
+static const comedi_lrange range_das16jr = { 9, {
+			// also used by 16/330
+			BIP_RANGE(10),
+			BIP_RANGE(5),
+			BIP_RANGE(2.5),
+			BIP_RANGE(1.25),
+			BIP_RANGE(0.625),
+			UNI_RANGE(10),
+			UNI_RANGE(5),
+			UNI_RANGE(2.5),
+			UNI_RANGE(1.25),
+	}
+};
+static const comedi_lrange range_das16jr_16 = { 8, {
+			BIP_RANGE(10),
+			BIP_RANGE(5),
+			BIP_RANGE(2.5),
+			BIP_RANGE(1.25),
+			UNI_RANGE(10),
+			UNI_RANGE(5),
+			UNI_RANGE(2.5),
+			UNI_RANGE(1.25),
+	}
+};
+
+static const int das16jr_gainlist[] = { 8, 0, 1, 2, 3, 4, 5, 6, 7 };
+static const int das16jr_16_gainlist[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
+static const int das1600_gainlist[] = { 0, 1, 2, 3 };
+enum {
+	das16_pg_none = 0,
+	das16_pg_16jr,
+	das16_pg_16jr_16,
+	das16_pg_1601,
+	das16_pg_1602,
+};
+static const int *const das16_gainlists[] = {
+	NULL,
+	das16jr_gainlist,
+	das16jr_16_gainlist,
+	das1600_gainlist,
+	das1600_gainlist,
+};
+static const comedi_lrange *const das16_ai_uni_lranges[] = {
+	&range_unknown,
+	&range_das16jr,
+	&range_das16jr_16,
+	&range_das1x01_unip,
+	&range_das1x02_unip,
+};
+static const comedi_lrange *const das16_ai_bip_lranges[] = {
+	&range_unknown,
+	&range_das16jr,
+	&range_das16jr_16,
+	&range_das1x01_bip,
+	&range_das1x02_bip,
+};
+
+struct munge_info {
+	uint8_t byte;
+	unsigned have_byte:1;
+};
+
+static int das16_ao_winsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static int das16_do_wbits(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static int das16_di_rbits(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static int das16_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+
+static int das16_cmd_test(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd);
+static int das16_cmd_exec(comedi_device * dev, comedi_subdevice * s);
+static int das16_cancel(comedi_device * dev, comedi_subdevice * s);
+static void das16_ai_munge(comedi_device * dev, comedi_subdevice * s,
+	void *array, unsigned int num_bytes, unsigned int start_chan_index);
+
+static void das16_reset(comedi_device * dev);
+static irqreturn_t das16_dma_interrupt(int irq, void *d PT_REGS_ARG);
+static void das16_timer_interrupt(unsigned long arg);
+static void das16_interrupt(comedi_device * dev);
+
+static unsigned int das16_set_pacer(comedi_device * dev, unsigned int ns,
+	int flags);
+static int das1600_mode_detect(comedi_device * dev);
+static unsigned int das16_suggest_transfer_size(comedi_device * dev,
+	comedi_cmd cmd);
+
+static void reg_dump(comedi_device * dev);
+
+typedef struct das16_board_struct {
+	const char *name;
+	void *ai;
+	unsigned int ai_nbits;
+	unsigned int ai_speed;	// max conversion speed in nanosec
+	unsigned int ai_pg;
+	void *ao;
+	unsigned int ao_nbits;
+	void *di;
+	void *do_;
+
+	unsigned int i8255_offset;
+	unsigned int i8254_offset;
+
+	unsigned int size;
+	unsigned int id;
+} das16_board;
+
+static const struct das16_board_struct das16_boards[] = {
+	{
+	      name:	"das-16",
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:15000,
+	      ai_pg:	das16_pg_none,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x10,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+	      id:	0x00,
+		},
+	{
+	      name:	"das-16g",
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:15000,
+	      ai_pg:	das16_pg_none,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x10,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+	      id:	0x00,
+		},
+	{
+	      name:	"das-16f",
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:8500,
+	      ai_pg:	das16_pg_none,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x10,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+	      id:	0x00,
+		},
+	{
+	      name:	"cio-das16",	// cio-das16.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:20000,
+	      ai_pg:	das16_pg_none,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x10,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+	      id:	0x80,
+		},
+	{
+	      name:	"cio-das16/f",	// das16.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_none,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x10,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+	      id:	0x80,
+		},
+	{
+	      name:	"cio-das16/jr",	// cio-das16jr.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:7692,
+	      ai_pg:	das16_pg_16jr,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x10,
+	      id:	0x00,
+		},
+	{
+	      name:	"pc104-das16jr",	// pc104-das16jr_xx.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:3300,
+	      ai_pg:	das16_pg_16jr,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x10,
+	      id:	0x00,
+		},
+	{
+	      name:	"cio-das16jr/16",	// cio-das16jr_16.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:16,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_16jr_16,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x10,
+	      id:	0x00,
+		},
+	{
+	      name:	"pc104-das16jr/16",	// pc104-das16jr_xx.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:16,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_16jr_16,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x10,
+	      id:	0x00,
+		},
+	{
+	      name:	"das-1201",	// 4924.pdf (keithley user's manual)
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:20000,
+	      ai_pg:	das16_pg_none,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+	      id:	0x20,
+		},
+	{
+	      name:	"das-1202",	// 4924.pdf (keithley user's manual)
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_none,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+	      id:	0x20,
+		},
+	{
+	      name:	"das-1401",	// 4919.pdf and 4922.pdf (keithley user's manual)
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1601,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x0,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+	      id:	0xc0	// 4919.pdf says id bits are 0xe0, 4922.pdf says 0xc0
+		},
+	{
+	      name:	"das-1402",	// 4919.pdf and 4922.pdf (keithley user's manual)
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1602,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x0,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+	      id:	0xc0	// 4919.pdf says id bits are 0xe0, 4922.pdf says 0xc0
+		},
+	{
+	      name:	"das-1601",	// 4919.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1601,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"das-1602",	// 4919.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1602,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1401/12",	// cio-das1400_series.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:6250,
+	      ai_pg:	das16_pg_1601,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1402/12",	// cio-das1400_series.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:6250,
+	      ai_pg:	das16_pg_1602,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1402/16",	// cio-das1400_series.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:16,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1602,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1601/12",	// cio-das160x-1x.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:6250,
+	      ai_pg:	das16_pg_1601,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1602/12",	// cio-das160x-1x.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1602,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das1602/16",	// cio-das160x-1x.pdf
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:16,
+	      ai_speed:10000,
+	      ai_pg:	das16_pg_1602,
+	      ao:	das16_ao_winsn,
+	      ao_nbits:12,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0x400,
+	      i8254_offset:0x0c,
+	      size:	0x408,
+      id:	0xc0},
+	{
+	      name:	"cio-das16/330",	// ?
+	      ai:	das16_ai_rinsn,
+	      ai_nbits:12,
+	      ai_speed:3030,
+	      ai_pg:	das16_pg_16jr,
+	      ao:	NULL,
+	      di:	das16_di_rbits,
+	      do_:	das16_do_wbits,
+	      i8255_offset:0,
+	      i8254_offset:0x0c,
+	      size:	0x14,
+      id:	0xf0},
+#if 0
+	{
+	      name:	"das16/330i",	// ?
+		},
+	{
+	      name:	"das16/jr/ctr5",	// ?
+		},
+	{
+	      name:	"cio-das16/m1/16",	// cio-das16_m1_16.pdf, this board is a bit quirky, no dma
+		},
+#endif
+};
+
+#define n_das16_boards ((sizeof(das16_boards))/(sizeof(das16_board)))
+
+static int das16_attach(comedi_device * dev, comedi_devconfig * it);
+static int das16_detach(comedi_device * dev);
+static comedi_driver driver_das16 = {
+      driver_name:"das16",
+      module:THIS_MODULE,
+      attach:das16_attach,
+      detach:das16_detach,
+      board_name:&das16_boards[0].name,
+      num_names:n_das16_boards,
+      offset:sizeof(das16_boards[0]),
+};
+
+#define DAS16_TIMEOUT 1000
+
+/* Period for timer interrupt in jiffies.  It's a function
+ * to deal with possibility of dynamic HZ patches  */
+static inline int timer_period(void)
+{
+	return HZ / 20;
+}
+struct das16_private_struct {
+	unsigned int ai_unipolar;	// unipolar flag
+	unsigned int ai_singleended;	// single ended flag
+	unsigned int clockbase;	// master clock speed in ns
+	volatile unsigned int control_state;	// dma, interrupt and trigger control bits
+	volatile unsigned long adc_byte_count;	// number of bytes remaining
+	unsigned int divisor1;	// divisor dividing master clock to get conversion frequency
+	unsigned int divisor2;	// divisor dividing master clock to get conversion frequency
+	unsigned int dma_chan;	// dma channel
+	uint16_t *dma_buffer[2];
+	dma_addr_t dma_buffer_addr[2];
+	unsigned int current_buffer;
+	volatile unsigned int dma_transfer_size;	// target number of bytes to transfer per dma shot
+	// user-defined analog input and output ranges defined from config options
+	comedi_lrange *user_ai_range_table;
+	comedi_lrange *user_ao_range_table;
+
+	struct timer_list timer;	// for timed interrupt
+	volatile short timer_running;
+	volatile short timer_mode;	// true if using timer mode
+};
+#define devpriv ((struct das16_private_struct *)(dev->private))
+#define thisboard ((struct das16_board_struct *)(dev->board_ptr))
+
+static int das16_cmd_test(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd)
+{
+	int err = 0, tmp;
+	int gain, start_chan, i;
+	int mask;
+
+	/* make sure triggers are valid */
+	tmp = cmd->start_src;
+	cmd->start_src &= TRIG_NOW;
+	if (!cmd->start_src || tmp != cmd->start_src)
+		err++;
+
+	tmp = cmd->scan_begin_src;
+	mask = TRIG_FOLLOW;
+	// if board supports burst mode
+	if (thisboard->size > 0x400)
+		mask |= TRIG_TIMER | TRIG_EXT;
+	cmd->scan_begin_src &= mask;
+	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
+		err++;
+
+	tmp = cmd->convert_src;
+	mask = TRIG_TIMER | TRIG_EXT;
+	// if board supports burst mode
+	if (thisboard->size > 0x400)
+		mask |= TRIG_NOW;
+	cmd->convert_src &= mask;
+	if (!cmd->convert_src || tmp != cmd->convert_src)
+		err++;
+
+	tmp = cmd->scan_end_src;
+	cmd->scan_end_src &= TRIG_COUNT;
+	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
+		err++;
+
+	tmp = cmd->stop_src;
+	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
+	if (!cmd->stop_src || tmp != cmd->stop_src)
+		err++;
+
+	if (err)
+		return 1;
+
+	/* step 2: make sure trigger sources are unique and mutually compatible */
+	if (cmd->scan_begin_src != TRIG_TIMER &&
+		cmd->scan_begin_src != TRIG_EXT &&
+		cmd->scan_begin_src != TRIG_FOLLOW)
+		err++;
+	if (cmd->convert_src != TRIG_TIMER &&
+		cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
+		err++;
+	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
+		err++;
+
+	// make sure scan_begin_src and convert_src dont conflict
+	if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
+		err++;
+	if (cmd->scan_begin_src != TRIG_FOLLOW && cmd->convert_src != TRIG_NOW)
+		err++;
+
+	if (err)
+		return 2;
+
+	/* step 3: make sure arguments are trivially compatible */
+	if (cmd->start_arg != 0) {
+		cmd->start_arg = 0;
+		err++;
+	}
+
+	if (cmd->scan_begin_src == TRIG_FOLLOW) {
+		/* internal trigger */
+		if (cmd->scan_begin_arg != 0) {
+			cmd->scan_begin_arg = 0;
+			err++;
+		}
+	}
+
+	if (cmd->scan_end_arg != cmd->chanlist_len) {
+		cmd->scan_end_arg = cmd->chanlist_len;
+		err++;
+	}
+	// check against maximum frequency
+	if (cmd->scan_begin_src == TRIG_TIMER) {
+		if (cmd->scan_begin_arg <
+			thisboard->ai_speed * cmd->chanlist_len) {
+			cmd->scan_begin_arg =
+				thisboard->ai_speed * cmd->chanlist_len;
+			err++;
+		}
+	}
+	if (cmd->convert_src == TRIG_TIMER) {
+		if (cmd->convert_arg < thisboard->ai_speed) {
+			cmd->convert_arg = thisboard->ai_speed;
+			err++;
+		}
+	}
+
+	if (cmd->stop_src == TRIG_NONE) {
+		if (cmd->stop_arg != 0) {
+			cmd->stop_arg = 0;
+			err++;
+		}
+	}
+	if (err)
+		return 3;
+
+	// step 4: fix up arguments
+	if (cmd->scan_begin_src == TRIG_TIMER) {
+		unsigned int tmp = cmd->scan_begin_arg;
+		// set divisors, correct timing arguments
+		i8253_cascade_ns_to_timer_2div(devpriv->clockbase,
+			&(devpriv->divisor1), &(devpriv->divisor2),
+			&(cmd->scan_begin_arg), cmd->flags & TRIG_ROUND_MASK);
+		err += (tmp != cmd->scan_begin_arg);
+	}
+	if (cmd->convert_src == TRIG_TIMER) {
+		unsigned int tmp = cmd->convert_arg;
+		// set divisors, correct timing arguments
+		i8253_cascade_ns_to_timer_2div(devpriv->clockbase,
+			&(devpriv->divisor1), &(devpriv->divisor2),
+			&(cmd->convert_arg), cmd->flags & TRIG_ROUND_MASK);
+		err += (tmp != cmd->convert_arg);
+	}
+	if (err)
+		return 4;
+
+	// check channel/gain list against card's limitations
+	if (cmd->chanlist) {
+		gain = CR_RANGE(cmd->chanlist[0]);
+		start_chan = CR_CHAN(cmd->chanlist[0]);
+		for (i = 1; i < cmd->chanlist_len; i++) {
+			if (CR_CHAN(cmd->chanlist[i]) !=
+				(start_chan + i) % s->n_chan) {
+				comedi_error(dev,
+					"entries in chanlist must be consecutive channels, counting upwards\n");
+				err++;
+			}
+			if (CR_RANGE(cmd->chanlist[i]) != gain) {
+				comedi_error(dev,
+					"entries in chanlist must all have the same gain\n");
+				err++;
+			}
+		}
+	}
+	if (err)
+		return 5;
+
+	return 0;
+}
+
+static int das16_cmd_exec(comedi_device * dev, comedi_subdevice * s)
+{
+	comedi_async *async = s->async;
+	comedi_cmd *cmd = &async->cmd;
+	unsigned int byte;
+	unsigned long flags;
+	int range;
+
+	if (devpriv->dma_chan == 0 || (dev->irq == 0
+			&& devpriv->timer_mode == 0)) {
+		comedi_error(dev,
+			"irq (or use of 'timer mode') dma required to execute comedi_cmd");
+		return -1;
+	}
+	if (cmd->flags & TRIG_RT) {
+		comedi_error(dev,
+			"isa dma transfers cannot be performed with TRIG_RT, aborting");
+		return -1;
+	}
+
+	devpriv->adc_byte_count =
+		cmd->stop_arg * cmd->chanlist_len * sizeof(uint16_t);
+
+	// disable conversions for das1600 mode
+	if (thisboard->size > 0x400) {
+		outb(DAS1600_CONV_DISABLE, dev->iobase + DAS1600_CONV);
+	}
+	// set scan limits
+	byte = CR_CHAN(cmd->chanlist[0]);
+	byte |= CR_CHAN(cmd->chanlist[cmd->chanlist_len - 1]) << 4;
+	outb(byte, dev->iobase + DAS16_MUX);
+
+	/* set gain (this is also burst rate register but according to
+	 * computer boards manual, burst rate does nothing, even on keithley cards) */
+	if (thisboard->ai_pg != das16_pg_none) {
+		range = CR_RANGE(cmd->chanlist[0]);
+		outb((das16_gainlists[thisboard->ai_pg])[range],
+			dev->iobase + DAS16_GAIN);
+	}
+
+	/* set counter mode and counts */
+	cmd->convert_arg =
+		das16_set_pacer(dev, cmd->convert_arg,
+		cmd->flags & TRIG_ROUND_MASK);
+	DEBUG_PRINT("pacer period: %d ns\n", cmd->convert_arg);
+
+	/* enable counters */
+	byte = 0;
+	/* Enable burst mode if appropriate. */
+	if (thisboard->size > 0x400) {
+		if (cmd->convert_src == TRIG_NOW) {
+			outb(DAS1600_BURST_VAL, dev->iobase + DAS1600_BURST);
+			// set burst length
+			byte |= BURST_LEN_BITS(cmd->chanlist_len - 1);
+		} else {
+			outb(0, dev->iobase + DAS1600_BURST);
+		}
+	}
+	outb(byte, dev->iobase + DAS16_PACER);
+
+	// set up dma transfer
+	flags = claim_dma_lock();
+	disable_dma(devpriv->dma_chan);
+	/* clear flip-flop to make sure 2-byte registers for
+	 * count and address get set correctly */
+	clear_dma_ff(devpriv->dma_chan);
+	devpriv->current_buffer = 0;
+	set_dma_addr(devpriv->dma_chan,
+		devpriv->dma_buffer_addr[devpriv->current_buffer]);
+	// set appropriate size of transfer
+	devpriv->dma_transfer_size = das16_suggest_transfer_size(dev, *cmd);
+	set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
+	enable_dma(devpriv->dma_chan);
+	release_dma_lock(flags);
+
+	// set up interrupt
+	if (devpriv->timer_mode) {
+		devpriv->timer_running = 1;
+		devpriv->timer.expires = jiffies + timer_period();
+		add_timer(&devpriv->timer);
+		devpriv->control_state &= ~DAS16_INTE;
+	} else {
+		/* clear interrupt bit */
+		outb(0x00, dev->iobase + DAS16_STATUS);
+		/* enable interrupts */
+		devpriv->control_state |= DAS16_INTE;
+	}
+	devpriv->control_state |= DMA_ENABLE;
+	devpriv->control_state &= ~PACING_MASK;
+	if (cmd->convert_src == TRIG_EXT)
+		devpriv->control_state |= EXT_PACER;
+	else
+		devpriv->control_state |= INT_PACER;
+	outb(devpriv->control_state, dev->iobase + DAS16_CONTROL);
+
+	/* Enable conversions if using das1600 mode */
+	if (thisboard->size > 0x400) {
+		outb(0, dev->iobase + DAS1600_CONV);
+	}
+
+	return 0;
+}
+
+static int das16_cancel(comedi_device * dev, comedi_subdevice * s)
+{
+	unsigned long flags;
+
+	comedi_spin_lock_irqsave(&dev->spinlock, flags);
+	/* disable interrupts, dma and pacer clocked conversions */
+	devpriv->control_state &= ~DAS16_INTE & ~PACING_MASK & ~DMA_ENABLE;
+	outb(devpriv->control_state, dev->iobase + DAS16_CONTROL);
+	if (devpriv->dma_chan)
+		disable_dma(devpriv->dma_chan);
+
+	// disable SW timer
+	if (devpriv->timer_mode && devpriv->timer_running) {
+		devpriv->timer_running = 0;
+		del_timer(&devpriv->timer);
+	}
+
+	/* disable burst mode */
+	if (thisboard->size > 0x400) {
+		outb(0, dev->iobase + DAS1600_BURST);
+	}
+
+	comedi_spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	return 0;
+}
+
+static void das16_reset(comedi_device * dev)
+{
+	outb(0, dev->iobase + DAS16_STATUS);
+	outb(0, dev->iobase + DAS16_CONTROL);
+	outb(0, dev->iobase + DAS16_PACER);
+	outb(0, dev->iobase + DAS16_CNTR_CONTROL);
+}
+
+static int das16_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i, n;
+	int range;
+	int chan;
+	int msb, lsb;
+
+	// disable interrupts and pacing
+	devpriv->control_state &= ~DAS16_INTE & ~DMA_ENABLE & ~PACING_MASK;
+	outb(devpriv->control_state, dev->iobase + DAS16_CONTROL);
+
+	/* set multiplexer */
+	chan = CR_CHAN(insn->chanspec);
+	chan |= CR_CHAN(insn->chanspec) << 4;
+	outb(chan, dev->iobase + DAS16_MUX);
+
+	/* set gain */
+	if (thisboard->ai_pg != das16_pg_none) {
+		range = CR_RANGE(insn->chanspec);
+		outb((das16_gainlists[thisboard->ai_pg])[range],
+			dev->iobase + DAS16_GAIN);
+	}
+
+	for (n = 0; n < insn->n; n++) {
+		/* trigger conversion */
+		outb_p(0, dev->iobase + DAS16_TRIG);
+
+		for (i = 0; i < DAS16_TIMEOUT; i++) {
+			if (!(inb(dev->iobase + DAS16_STATUS) & BUSY))
+				break;
+		}
+		if (i == DAS16_TIMEOUT) {
+			rt_printk("das16: timeout\n");
+			return -ETIME;
+		}
+		msb = inb(dev->iobase + DAS16_AI_MSB);
+		lsb = inb(dev->iobase + DAS16_AI_LSB);
+		if (thisboard->ai_nbits == 12) {
+			data[n] = ((lsb >> 4) & 0xf) | (msb << 4);
+		} else {
+			data[n] = lsb | (msb << 8);
+		}
+	}
+
+	return n;
+}
+
+static int das16_di_rbits(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	lsampl_t bits;
+
+	bits = inb(dev->iobase + DAS16_DIO) & 0xf;
+	data[1] = bits;
+	data[0] = 0;
+
+	return 2;
+}
+
+static int das16_do_wbits(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	lsampl_t wbits;
+
+	// only set bits that have been masked
+	data[0] &= 0xf;
+	wbits = s->state;
+	// zero bits that have been masked
+	wbits &= ~data[0];
+	// set masked bits
+	wbits |= data[0] & data[1];
+	s->state = wbits;
+	data[1] = wbits;
+
+	outb(s->state, dev->iobase + DAS16_DIO);
+
+	return 2;
+}
+
+static int das16_ao_winsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i;
+	int lsb, msb;
+	int chan;
+
+	chan = CR_CHAN(insn->chanspec);
+
+	for (i = 0; i < insn->n; i++) {
+		if (thisboard->ao_nbits == 12) {
+			lsb = (data[i] << 4) & 0xff;
+			msb = (data[i] >> 4) & 0xff;
+		} else {
+			lsb = data[i] & 0xff;
+			msb = (data[i] >> 8) & 0xff;
+		}
+		outb(lsb, dev->iobase + DAS16_AO_LSB(chan));
+		outb(msb, dev->iobase + DAS16_AO_MSB(chan));
+	}
+
+	return i;
+}
+
+static irqreturn_t das16_dma_interrupt(int irq, void *d PT_REGS_ARG)
+{
+	int status;
+	comedi_device *dev = d;
+
+	status = inb(dev->iobase + DAS16_STATUS);
+
+	if ((status & DAS16_INT) == 0) {
+		DEBUG_PRINT("spurious interrupt\n");
+		return IRQ_NONE;
+	}
+
+	/* clear interrupt */
+	outb(0x00, dev->iobase + DAS16_STATUS);
+	das16_interrupt(dev);
+	return IRQ_HANDLED;
+}
+
+static void das16_timer_interrupt(unsigned long arg)
+{
+	comedi_device *dev = (comedi_device *) arg;
+
+	das16_interrupt(dev);
+
+	if (devpriv->timer_running)
+		mod_timer(&devpriv->timer, jiffies + timer_period());
+}
+
+/* the pc104-das16jr (at least) has problems if the dma
+	transfer is interrupted in the middle of transferring
+	a 16 bit sample, so this function takes care to get
+	an even transfer count after disabling dma
+	channel.
+*/
+static int disable_dma_on_even(comedi_device * dev)
+{
+	int residue;
+	int i;
+	static const int disable_limit = 100;
+	static const int enable_timeout = 100;
+	disable_dma(devpriv->dma_chan);
+	residue = get_dma_residue(devpriv->dma_chan);
+	for (i = 0; i < disable_limit && (residue % 2); ++i) {
+		int j;
+		enable_dma(devpriv->dma_chan);
+		for (j = 0; j < enable_timeout; ++j) {
+			int new_residue;
+			comedi_udelay(2);
+			new_residue = get_dma_residue(devpriv->dma_chan);
+			if (new_residue != residue)
+				break;
+		}
+		disable_dma(devpriv->dma_chan);
+		residue = get_dma_residue(devpriv->dma_chan);
+	}
+	if (i == disable_limit) {
+		comedi_error(dev,
+			"failed to get an even dma transfer, could be trouble.");
+	}
+	return residue;
+}
+
+static void das16_interrupt(comedi_device * dev)
+{
+	unsigned long dma_flags, spin_flags;
+	comedi_subdevice *s = dev->read_subdev;
+	comedi_async *async;
+	comedi_cmd *cmd;
+	int num_bytes, residue;
+	int buffer_index;
+
+	if (dev->attached == 0) {
+		comedi_error(dev, "premature interrupt");
+		return;
+	}
+	// initialize async here to make sure it is not NULL
+	async = s->async;
+	cmd = &async->cmd;
+
+	if (devpriv->dma_chan == 0) {
+		comedi_error(dev, "interrupt with no dma channel?");
+		return;
+	}
+
+	comedi_spin_lock_irqsave(&dev->spinlock, spin_flags);
+	if ((devpriv->control_state & DMA_ENABLE) == 0) {
+		comedi_spin_unlock_irqrestore(&dev->spinlock, spin_flags);
+		DEBUG_PRINT("interrupt while dma disabled?\n");
+		return;
+	}
+
+	dma_flags = claim_dma_lock();
+	clear_dma_ff(devpriv->dma_chan);
+	residue = disable_dma_on_even(dev);
+
+	// figure out how many points to read
+	if (residue > devpriv->dma_transfer_size) {
+		comedi_error(dev, "residue > transfer size!\n");
+		async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
+		num_bytes = 0;
+	} else
+		num_bytes = devpriv->dma_transfer_size - residue;
+
+	if (cmd->stop_src == TRIG_COUNT && num_bytes >= devpriv->adc_byte_count) {
+		num_bytes = devpriv->adc_byte_count;
+		async->events |= COMEDI_CB_EOA;
+	}
+
+	buffer_index = devpriv->current_buffer;
+	devpriv->current_buffer = (devpriv->current_buffer + 1) % 2;
+	devpriv->adc_byte_count -= num_bytes;
+
+	// figure out how many bytes for next transfer
+	if (cmd->stop_src == TRIG_COUNT && devpriv->timer_mode == 0 &&
+		devpriv->dma_transfer_size > devpriv->adc_byte_count)
+		devpriv->dma_transfer_size = devpriv->adc_byte_count;
+
+	// re-enable  dma
+	if ((async->events & COMEDI_CB_EOA) == 0) {
+		set_dma_addr(devpriv->dma_chan,
+			devpriv->dma_buffer_addr[devpriv->current_buffer]);
+		set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
+		enable_dma(devpriv->dma_chan);
+		/* reenable conversions for das1600 mode, (stupid hardware) */
+		if (thisboard->size > 0x400 && devpriv->timer_mode == 0) {
+			outb(0x00, dev->iobase + DAS1600_CONV);
+		}
+	}
+	release_dma_lock(dma_flags);
+
+	comedi_spin_unlock_irqrestore(&dev->spinlock, spin_flags);
+
+	cfc_write_array_to_buffer(s,
+		devpriv->dma_buffer[buffer_index], num_bytes);
+
+	cfc_handle_events(dev, s);
+}
+
+static unsigned int das16_set_pacer(comedi_device * dev, unsigned int ns,
+	int rounding_flags)
+{
+	i8253_cascade_ns_to_timer_2div(devpriv->clockbase, &(devpriv->divisor1),
+		&(devpriv->divisor2), &ns, rounding_flags & TRIG_ROUND_MASK);
+
+	/* Write the values of ctr1 and ctr2 into counters 1 and 2 */
+	i8254_load(dev->iobase + DAS16_CNTR0_DATA, 0, 1, devpriv->divisor1, 2);
+	i8254_load(dev->iobase + DAS16_CNTR0_DATA, 0, 2, devpriv->divisor2, 2);
+
+	return ns;
+}
+
+static void reg_dump(comedi_device * dev)
+{
+	DEBUG_PRINT("********DAS1600 REGISTER DUMP********\n");
+	DEBUG_PRINT("DAS16_MUX: %x\n", inb(dev->iobase + DAS16_MUX));
+	DEBUG_PRINT("DAS16_DIO: %x\n", inb(dev->iobase + DAS16_DIO));
+	DEBUG_PRINT("DAS16_STATUS: %x\n", inb(dev->iobase + DAS16_STATUS));
+	DEBUG_PRINT("DAS16_CONTROL: %x\n", inb(dev->iobase + DAS16_CONTROL));
+	DEBUG_PRINT("DAS16_PACER: %x\n", inb(dev->iobase + DAS16_PACER));
+	DEBUG_PRINT("DAS16_GAIN: %x\n", inb(dev->iobase + DAS16_GAIN));
+	DEBUG_PRINT("DAS16_CNTR_CONTROL: %x\n",
+		inb(dev->iobase + DAS16_CNTR_CONTROL));
+	DEBUG_PRINT("DAS1600_CONV: %x\n", inb(dev->iobase + DAS1600_CONV));
+	DEBUG_PRINT("DAS1600_BURST: %x\n", inb(dev->iobase + DAS1600_BURST));
+	DEBUG_PRINT("DAS1600_ENABLE: %x\n", inb(dev->iobase + DAS1600_ENABLE));
+	DEBUG_PRINT("DAS1600_STATUS_B: %x\n",
+		inb(dev->iobase + DAS1600_STATUS_B));
+}
+
+static int das16_probe(comedi_device * dev, comedi_devconfig * it)
+{
+	int status;
+	int diobits;
+
+	/* status is available on all boards */
+
+	status = inb(dev->iobase + DAS16_STATUS);
+
+	if ((status & UNIPOLAR)) {
+		devpriv->ai_unipolar = 1;
+	} else {
+		devpriv->ai_unipolar = 0;
+	}
+
+	if ((status & DAS16_MUXBIT)) {
+		devpriv->ai_singleended = 1;
+	} else {
+		devpriv->ai_singleended = 0;
+	}
+
+	/* diobits indicates boards */
+
+	diobits = inb(dev->iobase + DAS16_DIO) & 0xf0;
+
+	printk(" id bits are 0x%02x\n", diobits);
+	if (thisboard->id != diobits) {
+		printk(" requested board's id bits are 0x%x (ignore)\n",
+			thisboard->id);
+	}
+
+	return 0;
+}
+
+static int das1600_mode_detect(comedi_device * dev)
+{
+	int status = 0;
+
+	status = inb(dev->iobase + DAS1600_STATUS_B);
+
+	if (status & DAS1600_CLK_10MHZ) {
+		devpriv->clockbase = 100;
+		printk(" 10MHz pacer clock\n");
+	} else {
+		devpriv->clockbase = 1000;
+		printk(" 1MHz pacer clock\n");
+	}
+
+	reg_dump(dev);
+
+	return 0;
+}
+
+/*
+ *
+ * Options list:
+ *   0  I/O base
+ *   1  IRQ
+ *   2  DMA
+ *   3  Clock speed (in MHz)
+ */
+
+static int das16_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	comedi_subdevice *s;
+	int ret;
+	unsigned int irq;
+	unsigned long iobase;
+	unsigned int dma_chan;
+	int timer_mode;
+	unsigned long flags;
+	comedi_krange *user_ai_range, *user_ao_range;
+
+	iobase = it->options[0];
+#if 0
+	irq = it->options[1];
+	timer_mode = it->options[8];
+#endif
+	/* always use time_mode since using irq can drop samples while
+	 * waiting for dma done interrupt (due to hardware limitations) */
+	irq = 0;
+	timer_mode = 1;
+	if (timer_mode)
+		irq = 0;
+
+	printk("comedi%d: das16:", dev->minor);
+
+	// check that clock setting is valid
+	if (it->options[3]) {
+		if (it->options[3] != 0 &&
+			it->options[3] != 1 && it->options[3] != 10) {
+			printk("\n Invalid option.  Master clock must be set to 1 or 10 (MHz)\n");
+			return -EINVAL;
+		}
+	}
+
+	if ((ret = alloc_private(dev, sizeof(struct das16_private_struct))) < 0)
+		return ret;
+
+	if (thisboard->size < 0x400) {
+		printk(" 0x%04lx-0x%04lx\n", iobase, iobase + thisboard->size);
+		if (!request_region(iobase, thisboard->size, "das16")) {
+			printk(" I/O port conflict\n");
+			return -EIO;
+		}
+	} else {
+		printk(" 0x%04lx-0x%04lx 0x%04lx-0x%04lx\n",
+			iobase, iobase + 0x0f,
+			iobase + 0x400,
+			iobase + 0x400 + (thisboard->size & 0x3ff));
+		if (!request_region(iobase, 0x10, "das16")) {
+			printk(" I/O port conflict:  0x%04lx-0x%04lx\n",
+				iobase, iobase + 0x0f);
+			return -EIO;
+		}
+		if (!request_region(iobase + 0x400, thisboard->size & 0x3ff,
+				"das16")) {
+			release_region(iobase, 0x10);
+			printk(" I/O port conflict:  0x%04lx-0x%04lx\n",
+				iobase + 0x400,
+				iobase + 0x400 + (thisboard->size & 0x3ff));
+			return -EIO;
+		}
+	}
+
+	dev->iobase = iobase;
+
+	// probe id bits to make sure they are consistent
+	if (das16_probe(dev, it)) {
+		printk(" id bits do not match selected board, aborting\n");
+		return -EINVAL;
+	}
+	dev->board_name = thisboard->name;
+
+	// get master clock speed
+	if (thisboard->size < 0x400) {
+		if (it->options[3])
+			devpriv->clockbase = 1000 / it->options[3];
+		else
+			devpriv->clockbase = 1000;	// 1 MHz default
+	} else {
+		das1600_mode_detect(dev);
+	}
+
+	/* now for the irq */
+	if (irq > 1 && irq < 8) {
+		if ((ret = comedi_request_irq(irq, das16_dma_interrupt, 0,
+					"das16", dev)) < 0)
+			return ret;
+		dev->irq = irq;
+		printk(" ( irq = %u )", irq);
+	} else if (irq == 0) {
+		printk(" ( no irq )");
+	} else {
+		printk(" invalid irq\n");
+		return -EINVAL;
+	}
+
+	// initialize dma
+	dma_chan = it->options[2];
+	if (dma_chan == 1 || dma_chan == 3) {
+		// allocate dma buffers
+		int i;
+		for (i = 0; i < 2; i++) {
+			devpriv->dma_buffer[i] = pci_alloc_consistent(NULL,
+				DAS16_DMA_SIZE, &devpriv->dma_buffer_addr[i]);
+			if (devpriv->dma_buffer[i] == NULL)
+				return -ENOMEM;
+		}
+		if (request_dma(dma_chan, "das16")) {
+			printk(" failed to allocate dma channel %i\n",
+				dma_chan);
+			return -EINVAL;
+		}
+		devpriv->dma_chan = dma_chan;
+		flags = claim_dma_lock();
+		disable_dma(devpriv->dma_chan);
+		set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);
+		release_dma_lock(flags);
+		printk(" ( dma = %u)\n", dma_chan);
+	} else if (dma_chan == 0) {
+		printk(" ( no dma )\n");
+	} else {
+		printk(" invalid dma channel\n");
+		return -EINVAL;
+	}
+
+	// get any user-defined input range
+	if (thisboard->ai_pg == das16_pg_none &&
+		(it->options[4] || it->options[5])) {
+		// allocate single-range range table
+		devpriv->user_ai_range_table =
+			kmalloc(sizeof(comedi_lrange) + sizeof(comedi_krange),
+			GFP_KERNEL);
+		// initialize ai range
+		devpriv->user_ai_range_table->length = 1;
+		user_ai_range = devpriv->user_ai_range_table->range;
+		user_ai_range->min = it->options[4];
+		user_ai_range->max = it->options[5];
+		user_ai_range->flags = UNIT_volt;
+	}
+	// get any user-defined output range
+	if (it->options[6] || it->options[7]) {
+		// allocate single-range range table
+		devpriv->user_ao_range_table =
+			kmalloc(sizeof(comedi_lrange) + sizeof(comedi_krange),
+			GFP_KERNEL);
+		// initialize ao range
+		devpriv->user_ao_range_table->length = 1;
+		user_ao_range = devpriv->user_ao_range_table->range;
+		user_ao_range->min = it->options[6];
+		user_ao_range->max = it->options[7];
+		user_ao_range->flags = UNIT_volt;
+	}
+
+	if (timer_mode) {
+		init_timer(&(devpriv->timer));
+		devpriv->timer.function = das16_timer_interrupt;
+		devpriv->timer.data = (unsigned long)dev;
+	}
+	devpriv->timer_mode = timer_mode ? 1 : 0;
+
+	if ((ret = alloc_subdevices(dev, 5)) < 0)
+		return ret;
+
+	s = dev->subdevices + 0;
+	dev->read_subdev = s;
+	/* ai */
+	if (thisboard->ai) {
+		s->type = COMEDI_SUBD_AI;
+		s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
+		if (devpriv->ai_singleended) {
+			s->n_chan = 16;
+			s->len_chanlist = 16;
+			s->subdev_flags |= SDF_GROUND;
+		} else {
+			s->n_chan = 8;
+			s->len_chanlist = 8;
+			s->subdev_flags |= SDF_DIFF;
+		}
+		s->maxdata = (1 << thisboard->ai_nbits) - 1;
+		if (devpriv->user_ai_range_table) {	// user defined ai range
+			s->range_table = devpriv->user_ai_range_table;
+		} else if (devpriv->ai_unipolar) {
+			s->range_table = das16_ai_uni_lranges[thisboard->ai_pg];
+		} else {
+			s->range_table = das16_ai_bip_lranges[thisboard->ai_pg];
+		}
+		s->insn_read = thisboard->ai;
+		s->do_cmdtest = das16_cmd_test;
+		s->do_cmd = das16_cmd_exec;
+		s->cancel = das16_cancel;
+		s->munge = das16_ai_munge;
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	s = dev->subdevices + 1;
+	/* ao */
+	if (thisboard->ao) {
+		s->type = COMEDI_SUBD_AO;
+		s->subdev_flags = SDF_WRITABLE;
+		s->n_chan = 2;
+		s->maxdata = (1 << thisboard->ao_nbits) - 1;
+		if (devpriv->user_ao_range_table) {	// user defined ao range
+			s->range_table = devpriv->user_ao_range_table;
+		} else {
+			s->range_table = &range_unknown;
+		}
+		s->insn_write = thisboard->ao;
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	s = dev->subdevices + 2;
+	/* di */
+	if (thisboard->di) {
+		s->type = COMEDI_SUBD_DI;
+		s->subdev_flags = SDF_READABLE;
+		s->n_chan = 4;
+		s->maxdata = 1;
+		s->range_table = &range_digital;
+		s->insn_bits = thisboard->di;
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	s = dev->subdevices + 3;
+	/* do */
+	if (thisboard->do_) {
+		s->type = COMEDI_SUBD_DO;
+		s->subdev_flags = SDF_WRITABLE | SDF_READABLE;
+		s->n_chan = 4;
+		s->maxdata = 1;
+		s->range_table = &range_digital;
+		s->insn_bits = thisboard->do_;
+		// initialize digital output lines
+		outb(s->state, dev->iobase + DAS16_DIO);
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	s = dev->subdevices + 4;
+	/* 8255 */
+	if (thisboard->i8255_offset != 0) {
+		subdev_8255_init(dev, s, NULL, (dev->iobase +
+				thisboard->i8255_offset));
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	das16_reset(dev);
+	/* set the interrupt level */
+	devpriv->control_state = DAS16_IRQ(dev->irq);
+	outb(devpriv->control_state, dev->iobase + DAS16_CONTROL);
+
+	// turn on das1600 mode if available
+	if (thisboard->size > 0x400) {
+		outb(DAS1600_ENABLE_VAL, dev->iobase + DAS1600_ENABLE);
+		outb(0, dev->iobase + DAS1600_CONV);
+		outb(0, dev->iobase + DAS1600_BURST);
+	}
+
+	return 0;
+}
+
+static int das16_detach(comedi_device * dev)
+{
+	printk("comedi%d: das16: remove\n", dev->minor);
+
+	das16_reset(dev);
+
+	if (dev->subdevices)
+		subdev_8255_cleanup(dev, dev->subdevices + 4);
+
+	if (devpriv) {
+		int i;
+		for (i = 0; i < 2; i++) {
+			if (devpriv->dma_buffer[i])
+				pci_free_consistent(NULL, DAS16_DMA_SIZE,
+					devpriv->dma_buffer[i],
+					devpriv->dma_buffer_addr[i]);
+		}
+		if (devpriv->dma_chan)
+			free_dma(devpriv->dma_chan);
+		if (devpriv->user_ai_range_table)
+			kfree(devpriv->user_ai_range_table);
+		if (devpriv->user_ao_range_table)
+			kfree(devpriv->user_ao_range_table);
+	}
+
+	if (dev->irq)
+		comedi_free_irq(dev->irq, dev);
+
+	if (dev->iobase) {
+		if (thisboard->size < 0x400) {
+			release_region(dev->iobase, thisboard->size);
+		} else {
+			release_region(dev->iobase, 0x10);
+			release_region(dev->iobase + 0x400,
+				thisboard->size & 0x3ff);
+		}
+	}
+
+	return 0;
+}
+
+COMEDI_INITCLEANUP(driver_das16);
+
+// utility function that suggests a dma transfer size in bytes
+static unsigned int das16_suggest_transfer_size(comedi_device * dev,
+	comedi_cmd cmd)
+{
+	unsigned int size;
+	unsigned int freq;
+
+	/* if we are using timer interrupt, we don't care how long it
+	 * will take to complete transfer since it will be interrupted
+	 * by timer interrupt */
+	if (devpriv->timer_mode)
+		return DAS16_DMA_SIZE;
+
+	/* otherwise, we are relying on dma terminal count interrupt,
+	 * so pick a reasonable size */
+	if (cmd.convert_src == TRIG_TIMER)
+		freq = 1000000000 / cmd.convert_arg;
+	else if (cmd.scan_begin_src == TRIG_TIMER)
+		freq = (1000000000 / cmd.scan_begin_arg) * cmd.chanlist_len;
+	// return some default value
+	else
+		freq = 0xffffffff;
+
+	if (cmd.flags & TRIG_WAKE_EOS) {
+		size = sample_size * cmd.chanlist_len;
+	} else {
+		// make buffer fill in no more than 1/3 second
+		size = (freq / 3) * sample_size;
+	}
+
+	// set a minimum and maximum size allowed
+	if (size > DAS16_DMA_SIZE)
+		size = DAS16_DMA_SIZE - DAS16_DMA_SIZE % sample_size;
+	else if (size < sample_size)
+		size = sample_size;
+
+	if (cmd.stop_src == TRIG_COUNT && size > devpriv->adc_byte_count)
+		size = devpriv->adc_byte_count;
+
+	return size;
+}
+
+static void das16_ai_munge(comedi_device * dev, comedi_subdevice * s,
+	void *array, unsigned int num_bytes, unsigned int start_chan_index)
+{
+	unsigned int i, num_samples = num_bytes / sizeof(sampl_t);
+	sampl_t *data = array;
+
+	for (i = 0; i < num_samples; i++) {
+		data[i] = le16_to_cpu(data[i]);
+		if (thisboard->ai_nbits == 12) {
+			data[i] = (data[i] >> 4) & 0xfff;
+		}
+	}
+}