Staging: comedi: add pcl816 driver

Driver for Advantech PCL-816 and PCL-814

From: Juan Grigera <juan@grigera.com.ar>
Cc: 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>

drivers/staging/comedi/drivers/pcl816.c

+/*
+   comedi/drivers/pcl816.c
+
+   Author:  Juan Grigera <juan@grigera.com.ar>
+            based on pcl818 by Michal Dobes <dobes@tesnet.cz> and bits of pcl812
+
+   hardware driver for Advantech cards:
+    card:   PCL-816, PCL814B
+    driver: pcl816
+*/
+/*
+Driver: pcl816
+Description: Advantech PCL-816 cards, PCL-814
+Author: Juan Grigera <juan@grigera.com.ar>
+Devices: [Advantech] PCL-816 (pcl816), PCL-814B (pcl814b)
+Status: works
+Updated: Tue,  2 Apr 2002 23:15:21 -0800
+
+PCL 816 and 814B have 16 SE/DIFF ADCs, 16 DACs, 16 DI and 16 DO.
+Differences are at resolution (16 vs 12 bits).
+
+The driver support AI command mode, other subdevices not written.
+
+Analog output and digital input and output are not supported.
+
+Configuration Options:
+  [0] - IO Base
+  [1] - IRQ	(0=disable, 2, 3, 4, 5, 6, 7)
+  [2] - DMA	(0=disable, 1, 3)
+  [3] - 0, 10=10MHz clock for 8254
+            1= 1MHz clock for 8254
+
+*/
+
+#include "../comedidev.h"
+
+#include <linux/ioport.h>
+#include <linux/mc146818rtc.h>
+#include <linux/delay.h>
+#include <asm/dma.h>
+
+#include "8253.h"
+
+#define DEBUG(x) x
+
+// boards constants
+// IO space len
+#define PCLx1x_RANGE 16
+
+//#define outb(x,y)  printk("OUTB(%x, 200+%d)\n", x,y-0x200); outb(x,y)
+
+// INTEL 8254 counters
+#define PCL816_CTR0 4
+#define PCL816_CTR1 5
+#define PCL816_CTR2 6
+// R: counter read-back register W: counter control
+#define PCL816_CTRCTL 7
+
+// R: A/D high byte W: A/D range control
+#define PCL816_RANGE 9
+// W: clear INT request
+#define PCL816_CLRINT 10
+// R: next mux scan channel W: mux scan channel & range control pointer
+#define PCL816_MUX 11
+// R/W: operation control register
+#define PCL816_CONTROL 12
+
+// R: return status byte  W: set DMA/IRQ
+#define PCL816_STATUS 13
+#define PCL816_STATUS_DRDY_MASK 0x80
+
+// R: low byte of A/D W: soft A/D trigger
+#define PCL816_AD_LO 8
+// R: high byte of A/D W: A/D range control
+#define PCL816_AD_HI 9
+
+// type of interrupt handler
+#define INT_TYPE_AI1_INT 1
+#define INT_TYPE_AI1_DMA 2
+#define INT_TYPE_AI3_INT 4
+#define INT_TYPE_AI3_DMA 5
+#ifdef unused
+#define INT_TYPE_AI1_DMA_RTC 9
+#define INT_TYPE_AI3_DMA_RTC 10
+
+// RTC stuff...
+#define RTC_IRQ 	8
+#define RTC_IO_EXTENT	0x10
+#endif
+
+#define MAGIC_DMA_WORD 0x5a5a
+
+static const comedi_lrange range_pcl816 = { 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),
+	}
+};
+typedef struct {
+	const char *name;	// board name
+	int n_ranges;		// len of range list
+	int n_aichan;		// num of A/D chans in diferencial mode
+	unsigned int ai_ns_min;	// minimal alllowed delay between samples (in ns)
+	int n_aochan;		// num of D/A chans
+	int n_dichan;		// num of DI chans
+	int n_dochan;		// num of DO chans
+	const comedi_lrange *ai_range_type;	// default A/D rangelist
+	const comedi_lrange *ao_range_type;	// dafault D/A rangelist
+	unsigned int io_range;	// len of IO space
+	unsigned int IRQbits;	// allowed interrupts
+	unsigned int DMAbits;	// allowed DMA chans
+	int ai_maxdata;		// maxdata for A/D
+	int ao_maxdata;		// maxdata for D/A
+	int ai_chanlist;	// allowed len of channel list A/D
+	int ao_chanlist;	// allowed len of channel list D/A
+	int i8254_osc_base;	// 1/frequency of on board oscilator in ns
+} boardtype;
+
+static const boardtype boardtypes[] = {
+	{"pcl816", 8, 16, 10000, 1, 16, 16, &range_pcl816,
+			&range_pcl816, PCLx1x_RANGE,
+			0x00fc,	// IRQ mask
+			0x0a,	// DMA mask
+			0xffff,	// 16-bit card
+			0xffff,	// D/A maxdata
+			1024,
+			1,	// ao chan list
+		100},
+	{"pcl814b", 8, 16, 10000, 1, 16, 16, &range_pcl816,
+			&range_pcl816, PCLx1x_RANGE,
+			0x00fc,
+			0x0a,
+			0x3fff,	/* 14 bit card */
+			0x3fff,
+			1024,
+			1,
+		100},
+};
+
+#define n_boardtypes (sizeof(boardtypes)/sizeof(boardtype))
+#define devpriv ((pcl816_private *)dev->private)
+#define this_board ((const boardtype *)dev->board_ptr)
+
+static int pcl816_attach(comedi_device * dev, comedi_devconfig * it);
+static int pcl816_detach(comedi_device * dev);
+
+#ifdef unused
+static int RTC_lock = 0;	/* RTC lock */
+static int RTC_timer_lock = 0;	/* RTC int lock */
+#endif
+
+static comedi_driver driver_pcl816 = {
+      driver_name:"pcl816",
+      module:THIS_MODULE,
+      attach:pcl816_attach,
+      detach:pcl816_detach,
+      board_name:&boardtypes[0].name,
+      num_names:n_boardtypes,
+      offset:sizeof(boardtype),
+};
+
+COMEDI_INITCLEANUP(driver_pcl816);
+
+typedef struct {
+	unsigned int dma;	// used DMA, 0=don't use DMA
+	int dma_rtc;		// 1=RTC used with DMA, 0=no RTC alloc
+#ifdef unused
+	unsigned long rtc_iobase;	// RTC port region
+	unsigned int rtc_iosize;
+	unsigned int rtc_irq;
+#endif
+	unsigned long dmabuf[2];	// pointers to begin of DMA buffers
+	unsigned int dmapages[2];	// len of DMA buffers in PAGE_SIZEs
+	unsigned int hwdmaptr[2];	// hardware address of DMA buffers
+	unsigned int hwdmasize[2];	// len of DMA buffers in Bytes
+	unsigned int dmasamplsize;	// size in samples hwdmasize[0]/2
+	unsigned int last_top_dma;	// DMA pointer in last RTC int
+	int next_dma_buf;	// which DMA buffer will be used next round
+	long dma_runs_to_end;	// how many we must permorm DMA transfer to end of record
+	unsigned long last_dma_run;	// how many bytes we must transfer on last DMA page
+
+	unsigned int ai_scans;	// len of scanlist
+	unsigned char ai_neverending;	// if=1, then we do neverending record (you must use cancel())
+	int irq_free;		// 1=have allocated IRQ
+	int irq_blocked;	// 1=IRQ now uses any subdev
+#ifdef unused
+	int rtc_irq_blocked;	// 1=we now do AI with DMA&RTC
+#endif
+	int irq_was_now_closed;	// when IRQ finish, there's stored int816_mode for last interrupt
+	int int816_mode;	// who now uses IRQ - 1=AI1 int, 2=AI1 dma, 3=AI3 int, 4AI3 dma
+	comedi_subdevice *last_int_sub;	// ptr to subdevice which now finish
+	int ai_act_scan;	// how many scans we finished
+	unsigned int ai_act_chanlist[16];	// MUX setting for actual AI operations
+	unsigned int ai_act_chanlist_len;	// how long is actual MUX list
+	unsigned int ai_act_chanlist_pos;	// actual position in MUX list
+	unsigned int ai_poll_ptr;	// how many sampes transfer poll
+	comedi_subdevice *sub_ai;	// ptr to AI subdevice
+#ifdef unused
+	struct timer_list rtc_irq_timer;	// timer for RTC sanity check
+	unsigned long rtc_freq;	// RTC int freq
+#endif
+} pcl816_private;
+
+/*
+==============================================================================
+*/
+static int check_and_setup_channel_list(comedi_device * dev,
+	comedi_subdevice * s, unsigned int *chanlist, int chanlen);
+static int pcl816_ai_cancel(comedi_device * dev, comedi_subdevice * s);
+static void start_pacer(comedi_device * dev, int mode, unsigned int divisor1,
+	unsigned int divisor2);
+#ifdef unused
+static int set_rtc_irq_bit(unsigned char bit);
+#endif
+
+static int pcl816_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd);
+static int pcl816_ai_cmd(comedi_device * dev, comedi_subdevice * s);
+
+/*
+==============================================================================
+   ANALOG INPUT MODE0, 816 cards, slow version
+*/
+static int pcl816_ai_insn_read(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int n;
+	int timeout;
+
+	DPRINTK("mode 0 analog input\n");
+	// software trigger, DMA and INT off
+	outb(0, dev->iobase + PCL816_CONTROL);
+	// clear INT (conversion end) flag
+	outb(0, dev->iobase + PCL816_CLRINT);
+
+	// Set the input channel
+	outb(CR_CHAN(insn->chanspec) & 0xf, dev->iobase + PCL816_MUX);
+	outb(CR_RANGE(insn->chanspec), dev->iobase + PCL816_RANGE);	/* select gain */
+
+	for (n = 0; n < insn->n; n++) {
+
+		outb(0, dev->iobase + PCL816_AD_LO);	/* start conversion */
+
+		timeout = 100;
+		while (timeout--) {
+			if (!(inb(dev->iobase + PCL816_STATUS) &
+					PCL816_STATUS_DRDY_MASK)) {
+				// return read value
+				data[n] =
+					((inb(dev->iobase +
+							PCL816_AD_HI) << 8) |
+					(inb(dev->iobase + PCL816_AD_LO)));
+
+				outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT (conversion end) flag */
+				break;
+			}
+			comedi_udelay(1);
+		}
+		// Return timeout error
+		if (!timeout) {
+			comedi_error(dev, "A/D insn timeout\n");
+			data[0] = 0;
+			outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT (conversion end) flag */
+			return -EIO;
+		}
+
+	}
+	return n;
+}
+
+/*
+==============================================================================
+   analog input interrupt mode 1 & 3, 818 cards
+   one sample per interrupt version
+*/
+static irqreturn_t interrupt_pcl816_ai_mode13_int(int irq, void *d)
+{
+	comedi_device *dev = d;
+	comedi_subdevice *s = dev->subdevices + 0;
+	int low, hi;
+	int timeout = 50;	/* wait max 50us */
+
+	while (timeout--) {
+		if (!(inb(dev->iobase + PCL816_STATUS) &
+				PCL816_STATUS_DRDY_MASK))
+			break;
+		comedi_udelay(1);
+	}
+	if (!timeout) {		// timeout, bail error
+		outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
+		comedi_error(dev, "A/D mode1/3 IRQ without DRDY!");
+		pcl816_ai_cancel(dev, s);
+		s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
+		comedi_event(dev, s);
+		return IRQ_HANDLED;
+
+	}
+
+	// get the sample
+	low = inb(dev->iobase + PCL816_AD_LO);
+	hi = inb(dev->iobase + PCL816_AD_HI);
+
+	comedi_buf_put(s->async, (hi << 8) | low);
+
+	outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
+
+	if (++devpriv->ai_act_chanlist_pos >= devpriv->ai_act_chanlist_len)
+		devpriv->ai_act_chanlist_pos = 0;
+
+	if (s->async->cur_chan == 0) {
+		devpriv->ai_act_scan++;
+	}
+
+	if (!devpriv->ai_neverending)
+		if (devpriv->ai_act_scan >= devpriv->ai_scans) {	/* all data sampled */
+			/* all data sampled */
+			pcl816_ai_cancel(dev, s);
+			s->async->events |= COMEDI_CB_EOA;
+		}
+	comedi_event(dev, s);
+	return IRQ_HANDLED;
+}
+
+/*
+==============================================================================
+   analog input dma mode 1 & 3, 816 cards
+*/
+static void transfer_from_dma_buf(comedi_device * dev, comedi_subdevice * s,
+	sampl_t * ptr, unsigned int bufptr, unsigned int len)
+{
+	int i;
+
+	s->async->events = 0;
+
+	for (i = 0; i < len; i++) {
+
+		comedi_buf_put(s->async, ptr[bufptr++]);
+
+		if (++devpriv->ai_act_chanlist_pos >=
+			devpriv->ai_act_chanlist_len) {
+			devpriv->ai_act_chanlist_pos = 0;
+			devpriv->ai_act_scan++;
+		}
+
+		if (!devpriv->ai_neverending)
+			if (devpriv->ai_act_scan >= devpriv->ai_scans) {	// all data sampled
+				pcl816_ai_cancel(dev, s);
+				s->async->events |= COMEDI_CB_EOA;
+				s->async->events |= COMEDI_CB_BLOCK;
+				break;
+			}
+	}
+
+	comedi_event(dev, s);
+}
+
+static irqreturn_t interrupt_pcl816_ai_mode13_dma(int irq, void *d)
+{
+	comedi_device *dev = d;
+	comedi_subdevice *s = dev->subdevices + 0;
+	int len, bufptr, this_dma_buf;
+	unsigned long dma_flags;
+	sampl_t *ptr;
+
+	disable_dma(devpriv->dma);
+	this_dma_buf = devpriv->next_dma_buf;
+
+	if ((devpriv->dma_runs_to_end > -1) || devpriv->ai_neverending) {	// switch dma bufs
+
+		devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
+		set_dma_mode(devpriv->dma, DMA_MODE_READ);
+		dma_flags = claim_dma_lock();
+//  clear_dma_ff (devpriv->dma);
+		set_dma_addr(devpriv->dma,
+			devpriv->hwdmaptr[devpriv->next_dma_buf]);
+		if (devpriv->dma_runs_to_end) {
+			set_dma_count(devpriv->dma,
+				devpriv->hwdmasize[devpriv->next_dma_buf]);
+		} else {
+			set_dma_count(devpriv->dma, devpriv->last_dma_run);
+		}
+		release_dma_lock(dma_flags);
+		enable_dma(devpriv->dma);
+	}
+
+	devpriv->dma_runs_to_end--;
+	outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
+
+	ptr = (sampl_t *) devpriv->dmabuf[this_dma_buf];
+
+	len = (devpriv->hwdmasize[0] >> 1) - devpriv->ai_poll_ptr;
+	bufptr = devpriv->ai_poll_ptr;
+	devpriv->ai_poll_ptr = 0;
+
+	transfer_from_dma_buf(dev, s, ptr, bufptr, len);
+	return IRQ_HANDLED;
+}
+
+/*
+==============================================================================
+    INT procedure
+*/
+static irqreturn_t interrupt_pcl816(int irq, void *d PT_REGS_ARG)
+{
+	comedi_device *dev = d;
+	DPRINTK("<I>");
+
+	if (!dev->attached) {
+		comedi_error(dev, "premature interrupt");
+		return IRQ_HANDLED;
+	}
+
+	switch (devpriv->int816_mode) {
+	case INT_TYPE_AI1_DMA:
+	case INT_TYPE_AI3_DMA:
+		return interrupt_pcl816_ai_mode13_dma(irq, d);
+	case INT_TYPE_AI1_INT:
+	case INT_TYPE_AI3_INT:
+		return interrupt_pcl816_ai_mode13_int(irq, d);
+	}
+
+	outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
+	if ((!dev->irq) | (!devpriv->irq_free) | (!devpriv->irq_blocked) |
+		(!devpriv->int816_mode)) {
+		if (devpriv->irq_was_now_closed) {
+			devpriv->irq_was_now_closed = 0;
+			// comedi_error(dev,"last IRQ..");
+			return IRQ_HANDLED;
+		}
+		comedi_error(dev, "bad IRQ!");
+		return IRQ_NONE;
+	}
+	comedi_error(dev, "IRQ from unknow source!");
+	return IRQ_NONE;
+}
+
+/*
+==============================================================================
+   COMMAND MODE
+*/
+static void pcl816_cmdtest_out(int e, comedi_cmd * cmd)
+{
+	rt_printk("pcl816 e=%d startsrc=%x scansrc=%x convsrc=%x\n", e,
+		cmd->start_src, cmd->scan_begin_src, cmd->convert_src);
+	rt_printk("pcl816 e=%d startarg=%d scanarg=%d convarg=%d\n", e,
+		cmd->start_arg, cmd->scan_begin_arg, cmd->convert_arg);
+	rt_printk("pcl816 e=%d stopsrc=%x scanend=%x\n", e, cmd->stop_src,
+		cmd->scan_end_src);
+	rt_printk("pcl816 e=%d stoparg=%d scanendarg=%d chanlistlen=%d\n", e,
+		cmd->stop_arg, cmd->scan_end_arg, cmd->chanlist_len);
+}
+
+/*
+==============================================================================
+*/
+static int pcl816_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd)
+{
+	int err = 0;
+	int tmp, divisor1, divisor2;
+
+	DEBUG(rt_printk("pcl816 pcl812_ai_cmdtest\n");
+		pcl816_cmdtest_out(-1, cmd););
+
+	/* step 1: make sure trigger sources are trivially valid */
+	tmp = cmd->start_src;
+	cmd->start_src &= TRIG_NOW;
+	if (!cmd->start_src || tmp != cmd->start_src)
+		err++;
+
+	tmp = cmd->scan_begin_src;
+	cmd->scan_begin_src &= TRIG_FOLLOW;
+	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
+		err++;
+
+	if (!cmd->convert_src & (TRIG_EXT | TRIG_TIMER))
+		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->start_src != TRIG_NOW) {
+		cmd->start_src = TRIG_NOW;
+		err++;
+	}
+
+	if (cmd->scan_begin_src != TRIG_FOLLOW) {
+		cmd->scan_begin_src = TRIG_FOLLOW;
+		err++;
+	}
+
+	if (cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_TIMER) {
+		cmd->convert_src = TRIG_TIMER;
+		err++;
+	}
+
+	if (cmd->scan_end_src != TRIG_COUNT) {
+		cmd->scan_end_src = TRIG_COUNT;
+		err++;
+	}
+
+	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
+		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_arg != 0) {
+		cmd->scan_begin_arg = 0;
+		err++;
+	}
+	if (cmd->convert_src == TRIG_TIMER) {
+		if (cmd->convert_arg < this_board->ai_ns_min) {
+			cmd->convert_arg = this_board->ai_ns_min;
+			err++;
+		}
+	} else {		/* TRIG_EXT */
+		if (cmd->convert_arg != 0) {
+			cmd->convert_arg = 0;
+			err++;
+		}
+	}
+
+	if (!cmd->chanlist_len) {
+		cmd->chanlist_len = 1;
+		err++;
+	}
+	if (cmd->chanlist_len > this_board->n_aichan) {
+		cmd->chanlist_len = this_board->n_aichan;
+		err++;
+	}
+	if (cmd->scan_end_arg != cmd->chanlist_len) {
+		cmd->scan_end_arg = cmd->chanlist_len;
+		err++;
+	}
+	if (cmd->stop_src == TRIG_COUNT) {
+		if (!cmd->stop_arg) {
+			cmd->stop_arg = 1;
+			err++;
+		}
+	} else {		/* TRIG_NONE */
+		if (cmd->stop_arg != 0) {
+			cmd->stop_arg = 0;
+			err++;
+		}
+	}
+
+	if (err) {
+		return 3;
+	}
+
+	/* step 4: fix up any arguments */
+	if (cmd->convert_src == TRIG_TIMER) {
+		tmp = cmd->convert_arg;
+		i8253_cascade_ns_to_timer(this_board->i8254_osc_base,
+			&divisor1, &divisor2, &cmd->convert_arg,
+			cmd->flags & TRIG_ROUND_MASK);
+		if (cmd->convert_arg < this_board->ai_ns_min)
+			cmd->convert_arg = this_board->ai_ns_min;
+		if (tmp != cmd->convert_arg)
+			err++;
+	}
+
+	if (err) {
+		return 4;
+	}
+
+	return 0;
+}
+
+static int pcl816_ai_cmd(comedi_device * dev, comedi_subdevice * s)
+{
+	unsigned int divisor1 = 0, divisor2 = 0, dma_flags, bytes, dmairq;
+	comedi_cmd *cmd = &s->async->cmd;
+
+	if (cmd->start_src != TRIG_NOW)
+		return -EINVAL;
+	if (cmd->scan_begin_src != TRIG_FOLLOW)
+		return -EINVAL;
+	if (cmd->scan_end_src != TRIG_COUNT)
+		return -EINVAL;
+	if (cmd->scan_end_arg != cmd->chanlist_len)
+		return -EINVAL;
+//      if(cmd->chanlist_len>MAX_CHANLIST_LEN) return -EINVAL;
+	if (devpriv->irq_blocked)
+		return -EBUSY;
+
+	if (cmd->convert_src == TRIG_TIMER) {
+		if (cmd->convert_arg < this_board->ai_ns_min)
+			cmd->convert_arg = this_board->ai_ns_min;
+
+		i8253_cascade_ns_to_timer(this_board->i8254_osc_base, &divisor1,
+			&divisor2, &cmd->convert_arg,
+			cmd->flags & TRIG_ROUND_MASK);
+		if (divisor1 == 1) {	// PCL816 crash if any divisor is set to 1
+			divisor1 = 2;
+			divisor2 /= 2;
+		}
+		if (divisor2 == 1) {
+			divisor2 = 2;
+			divisor1 /= 2;
+		}
+	}
+
+	start_pacer(dev, -1, 0, 0);	// stop pacer
+
+	if (!check_and_setup_channel_list(dev, s, cmd->chanlist,
+			cmd->chanlist_len))
+		return -EINVAL;
+	comedi_udelay(1);
+
+	devpriv->ai_act_scan = 0;
+	s->async->cur_chan = 0;
+	devpriv->irq_blocked = 1;
+	devpriv->ai_poll_ptr = 0;
+	devpriv->irq_was_now_closed = 0;
+
+	if (cmd->stop_src == TRIG_COUNT) {
+		devpriv->ai_scans = cmd->stop_arg;
+		devpriv->ai_neverending = 0;
+	} else {
+		devpriv->ai_scans = 0;
+		devpriv->ai_neverending = 1;
+	}
+
+	if ((cmd->flags & TRIG_WAKE_EOS)) {	// don't we want wake up every scan?
+		printk("pl816: You wankt WAKE_EOS but I dont want handle it");
+		//              devpriv->ai_eos=1;
+		//if (devpriv->ai_n_chan==1)
+		//      devpriv->dma=0; // DMA is useless for this situation
+	}
+
+	if (devpriv->dma) {
+		bytes = devpriv->hwdmasize[0];
+		if (!devpriv->ai_neverending) {
+			bytes = s->async->cmd.chanlist_len * s->async->cmd.chanlist_len * sizeof(sampl_t);	// how many
+			devpriv->dma_runs_to_end = bytes / devpriv->hwdmasize[0];	// how many DMA pages we must fill
+			devpriv->last_dma_run = bytes % devpriv->hwdmasize[0];	//on last dma transfer must be moved
+			devpriv->dma_runs_to_end--;
+			if (devpriv->dma_runs_to_end >= 0)
+				bytes = devpriv->hwdmasize[0];
+		} else
+			devpriv->dma_runs_to_end = -1;
+
+		devpriv->next_dma_buf = 0;
+		set_dma_mode(devpriv->dma, DMA_MODE_READ);
+		dma_flags = claim_dma_lock();
+		clear_dma_ff(devpriv->dma);
+		set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);
+		set_dma_count(devpriv->dma, bytes);
+		release_dma_lock(dma_flags);
+		enable_dma(devpriv->dma);
+	}
+
+	start_pacer(dev, 1, divisor1, divisor2);
+	dmairq = ((devpriv->dma & 0x3) << 4) | (dev->irq & 0x7);
+
+	switch (cmd->convert_src) {
+	case TRIG_TIMER:
+		devpriv->int816_mode = INT_TYPE_AI1_DMA;
+		outb(0x32, dev->iobase + PCL816_CONTROL);	// Pacer+IRQ+DMA
+		outb(dmairq, dev->iobase + PCL816_STATUS);	// write irq and DMA to card
+		break;
+
+	default:
+		devpriv->int816_mode = INT_TYPE_AI3_DMA;
+		outb(0x34, dev->iobase + PCL816_CONTROL);	// Ext trig+IRQ+DMA
+		outb(dmairq, dev->iobase + PCL816_STATUS);	// write irq to card
+		break;
+	}
+
+	DPRINTK("pcl816 END: pcl812_ai_cmd()\n");
+	return 0;
+}
+
+static int pcl816_ai_poll(comedi_device * dev, comedi_subdevice * s)
+{
+	unsigned long flags;
+	unsigned int top1, top2, i;
+
+	if (!devpriv->dma)
+		return 0;	// poll is valid only for DMA transfer
+
+	comedi_spin_lock_irqsave(&dev->spinlock, flags);
+
+	for (i = 0; i < 20; i++) {
+		top1 = get_dma_residue(devpriv->dma);	// where is now DMA
+		top2 = get_dma_residue(devpriv->dma);
+		if (top1 == top2)
+			break;
+	}
+	if (top1 != top2) {
+		comedi_spin_unlock_irqrestore(&dev->spinlock, flags);
+		return 0;
+	}
+
+	top1 = devpriv->hwdmasize[0] - top1;	// where is now DMA in buffer
+	top1 >>= 1;		// sample position
+	top2 = top1 - devpriv->ai_poll_ptr;
+	if (top2 < 1) {		// no new samples
+		comedi_spin_unlock_irqrestore(&dev->spinlock, flags);
+		return 0;
+	}
+
+	transfer_from_dma_buf(dev, s,
+		(sampl_t *) devpriv->dmabuf[devpriv->next_dma_buf],
+		devpriv->ai_poll_ptr, top2);
+
+	devpriv->ai_poll_ptr = top1;	// new buffer position
+	comedi_spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	return s->async->buf_write_count - s->async->buf_read_count;
+}
+
+/*
+==============================================================================
+ cancel any mode 1-4 AI
+*/
+static int pcl816_ai_cancel(comedi_device * dev, comedi_subdevice * s)
+{
+//  DEBUG(rt_printk("pcl816_ai_cancel()\n");)
+
+	if (devpriv->irq_blocked > 0) {
+		switch (devpriv->int816_mode) {
+#ifdef unused
+		case INT_TYPE_AI1_DMA_RTC:
+		case INT_TYPE_AI3_DMA_RTC:
+			set_rtc_irq_bit(0);	// stop RTC
+			del_timer(&devpriv->rtc_irq_timer);
+#endif
+		case INT_TYPE_AI1_DMA:
+		case INT_TYPE_AI3_DMA:
+			disable_dma(devpriv->dma);
+		case INT_TYPE_AI1_INT:
+		case INT_TYPE_AI3_INT:
+			outb(inb(dev->iobase + PCL816_CONTROL) & 0x73, dev->iobase + PCL816_CONTROL);	/* Stop A/D */
+			comedi_udelay(1);
+			outb(0, dev->iobase + PCL816_CONTROL);	/* Stop A/D */
+			outb(0xb0, dev->iobase + PCL816_CTRCTL);	/* Stop pacer */
+			outb(0x70, dev->iobase + PCL816_CTRCTL);
+			outb(0, dev->iobase + PCL816_AD_LO);
+			inb(dev->iobase + PCL816_AD_LO);
+			inb(dev->iobase + PCL816_AD_HI);
+			outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
+			outb(0, dev->iobase + PCL816_CONTROL);	/* Stop A/D */
+			devpriv->irq_blocked = 0;
+			devpriv->irq_was_now_closed = devpriv->int816_mode;
+			devpriv->int816_mode = 0;
+			devpriv->last_int_sub = s;
+//        s->busy = 0;
+			break;
+		}
+	}
+
+	DEBUG(rt_printk("comedi: pcl816_ai_cancel() successful\n");
+		)
+		return 0;
+}
+
+/*
+==============================================================================
+ chech for PCL816
+*/
+static int pcl816_check(unsigned long iobase)
+{
+	outb(0x00, iobase + PCL816_MUX);
+	comedi_udelay(1);
+	if (inb(iobase + PCL816_MUX) != 0x00)
+		return 1;	//there isn't card
+	outb(0x55, iobase + PCL816_MUX);
+	comedi_udelay(1);
+	if (inb(iobase + PCL816_MUX) != 0x55)
+		return 1;	//there isn't card
+	outb(0x00, iobase + PCL816_MUX);
+	comedi_udelay(1);
+	outb(0x18, iobase + PCL816_CONTROL);
+	comedi_udelay(1);
+	if (inb(iobase + PCL816_CONTROL) != 0x18)
+		return 1;	//there isn't card
+	return 0;		// ok, card exist
+}
+
+/*
+==============================================================================
+ reset whole PCL-816 cards
+*/
+static void pcl816_reset(comedi_device * dev)
+{
+//  outb (0, dev->iobase + PCL818_DA_LO);       // DAC=0V
+//  outb (0, dev->iobase + PCL818_DA_HI);
+//  comedi_udelay (1);
+//  outb (0, dev->iobase + PCL818_DO_HI);       // DO=$0000
+//  outb (0, dev->iobase + PCL818_DO_LO);
+//  comedi_udelay (1);
+	outb(0, dev->iobase + PCL816_CONTROL);
+	outb(0, dev->iobase + PCL816_MUX);
+	outb(0, dev->iobase + PCL816_CLRINT);
+	outb(0xb0, dev->iobase + PCL816_CTRCTL);	/* Stop pacer */
+	outb(0x70, dev->iobase + PCL816_CTRCTL);
+	outb(0x30, dev->iobase + PCL816_CTRCTL);
+	outb(0, dev->iobase + PCL816_RANGE);
+}
+
+/*
+==============================================================================
+ Start/stop pacer onboard pacer
+*/
+static void
+start_pacer(comedi_device * dev, int mode, unsigned int divisor1,
+	unsigned int divisor2)
+{
+	outb(0x32, dev->iobase + PCL816_CTRCTL);
+	outb(0xff, dev->iobase + PCL816_CTR0);
+	outb(0x00, dev->iobase + PCL816_CTR0);
+	comedi_udelay(1);
+	outb(0xb4, dev->iobase + PCL816_CTRCTL);	// set counter 2 as mode 3
+	outb(0x74, dev->iobase + PCL816_CTRCTL);	// set counter 1 as mode 3
+	comedi_udelay(1);
+
+	if (mode == 1) {
+		DPRINTK("mode %d, divisor1 %d, divisor2 %d\n", mode, divisor1,
+			divisor2);
+		outb(divisor2 & 0xff, dev->iobase + PCL816_CTR2);
+		outb((divisor2 >> 8) & 0xff, dev->iobase + PCL816_CTR2);
+		outb(divisor1 & 0xff, dev->iobase + PCL816_CTR1);
+		outb((divisor1 >> 8) & 0xff, dev->iobase + PCL816_CTR1);
+	}
+
+	/* clear pending interrupts (just in case) */
+//      outb(0, dev->iobase + PCL816_CLRINT);
+}
+
+/*
+==============================================================================
+ Check if channel list from user is builded correctly
+ If it's ok, then program scan/gain logic
+*/
+static int
+check_and_setup_channel_list(comedi_device * dev, comedi_subdevice * s,
+	unsigned int *chanlist, int chanlen)
+{
+	unsigned int chansegment[16];
+	unsigned int i, nowmustbechan, seglen, segpos;
+
+	// correct channel and range number check itself comedi/range.c
+	if (chanlen < 1) {
+		comedi_error(dev, "range/channel list is empty!");
+		return 0;
+	}
+
+	if (chanlen > 1) {
+		chansegment[0] = chanlist[0];	// first channel is everytime ok
+		for (i = 1, seglen = 1; i < chanlen; i++, seglen++) {
+			// build part of chanlist
+			DEBUG(rt_printk("%d. %d %d\n", i, CR_CHAN(chanlist[i]),
+					CR_RANGE(chanlist[i]));
+				)
+				if (chanlist[0] == chanlist[i])
+				break;	// we detect loop, this must by finish
+			nowmustbechan =
+				(CR_CHAN(chansegment[i - 1]) + 1) % chanlen;
+			if (nowmustbechan != CR_CHAN(chanlist[i])) {
+				// channel list isn't continous :-(
+				rt_printk
+					("comedi%d: pcl816: channel list must be continous! chanlist[%i]=%d but must be %d or %d!\n",
+					dev->minor, i, CR_CHAN(chanlist[i]),
+					nowmustbechan, CR_CHAN(chanlist[0]));
+				return 0;
+			}
+			chansegment[i] = chanlist[i];	// well, this is next correct channel in list
+		}
+
+		for (i = 0, segpos = 0; i < chanlen; i++) {	// check whole chanlist
+			DEBUG(rt_printk("%d %d=%d %d\n",
+					CR_CHAN(chansegment[i % seglen]),
+					CR_RANGE(chansegment[i % seglen]),
+					CR_CHAN(chanlist[i]),
+					CR_RANGE(chanlist[i]));
+				)
+				if (chanlist[i] != chansegment[i % seglen]) {
+				rt_printk
+					("comedi%d: pcl816: bad channel or range number! chanlist[%i]=%d,%d,%d and not %d,%d,%d!\n",
+					dev->minor, i, CR_CHAN(chansegment[i]),
+					CR_RANGE(chansegment[i]),
+					CR_AREF(chansegment[i]),
+					CR_CHAN(chanlist[i % seglen]),
+					CR_RANGE(chanlist[i % seglen]),
+					CR_AREF(chansegment[i % seglen]));
+				return 0;	// chan/gain list is strange
+			}
+		}
+	} else {
+		seglen = 1;
+	}
+
+	devpriv->ai_act_chanlist_len = seglen;
+	devpriv->ai_act_chanlist_pos = 0;
+
+	for (i = 0; i < seglen; i++) {	// store range list to card
+		devpriv->ai_act_chanlist[i] = CR_CHAN(chanlist[i]);
+		outb(CR_CHAN(chanlist[0]) & 0xf, dev->iobase + PCL816_MUX);
+		outb(CR_RANGE(chanlist[0]), dev->iobase + PCL816_RANGE);	/* select gain */
+	}
+
+	comedi_udelay(1);
+
+	outb(devpriv->ai_act_chanlist[0] | (devpriv->ai_act_chanlist[seglen - 1] << 4), dev->iobase + PCL816_MUX);	/* select channel interval to scan */
+
+	return 1;		// we can serve this with MUX logic
+}
+
+#ifdef unused
+/*
+==============================================================================
+  Enable(1)/disable(0) periodic interrupts from RTC
+*/
+static int set_rtc_irq_bit(unsigned char bit)
+{
+	unsigned char val;
+	unsigned long flags;
+
+	if (bit == 1) {
+		RTC_timer_lock++;
+		if (RTC_timer_lock > 1)
+			return 0;
+	} else {
+		RTC_timer_lock--;
+		if (RTC_timer_lock < 0)
+			RTC_timer_lock = 0;
+		if (RTC_timer_lock > 0)
+			return 0;
+	}
+
+	save_flags(flags);
+	cli();
+	val = CMOS_READ(RTC_CONTROL);
+	if (bit) {
+		val |= RTC_PIE;
+	} else {
+		val &= ~RTC_PIE;
+	}
+	CMOS_WRITE(val, RTC_CONTROL);
+	CMOS_READ(RTC_INTR_FLAGS);
+	restore_flags(flags);
+	return 0;
+}
+#endif
+
+/*
+==============================================================================
+  Free any resources that we have claimed
+*/
+static void free_resources(comedi_device * dev)
+{
+	//rt_printk("free_resource()\n");
+	if (dev->private) {
+		pcl816_ai_cancel(dev, devpriv->sub_ai);
+		pcl816_reset(dev);
+		if (devpriv->dma)
+			free_dma(devpriv->dma);
+		if (devpriv->dmabuf[0])
+			free_pages(devpriv->dmabuf[0], devpriv->dmapages[0]);
+		if (devpriv->dmabuf[1])
+			free_pages(devpriv->dmabuf[1], devpriv->dmapages[1]);
+#ifdef unused
+		if (devpriv->rtc_irq)
+			comedi_free_irq(devpriv->rtc_irq, dev);
+		if ((devpriv->dma_rtc) && (RTC_lock == 1)) {
+			if (devpriv->rtc_iobase)
+				release_region(devpriv->rtc_iobase,
+					devpriv->rtc_iosize);
+		}
+#endif
+	}
+
+	if (dev->irq)
+		free_irq(dev->irq, dev);
+	if (dev->iobase)
+		release_region(dev->iobase, this_board->io_range);
+	//rt_printk("free_resource() end\n");
+}
+
+/*
+==============================================================================
+
+   Initialization
+
+*/
+static int pcl816_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	int ret;
+	unsigned long iobase;
+	unsigned int irq, dma;
+	unsigned long pages;
+	//int i;
+	comedi_subdevice *s;
+
+	/* claim our I/O space */
+	iobase = it->options[0];
+	printk("comedi%d: pcl816:  board=%s, ioport=0x%03lx", dev->minor,
+		this_board->name, iobase);
+
+	if (!request_region(iobase, this_board->io_range, "pcl816")) {
+		rt_printk("I/O port conflict\n");
+		return -EIO;
+	}
+
+	dev->iobase = iobase;
+
+	if (pcl816_check(iobase)) {
+		rt_printk(", I cann't detect board. FAIL!\n");
+		return -EIO;
+	}
+
+	if ((ret = alloc_private(dev, sizeof(pcl816_private))) < 0)
+		return ret;	/* Can't alloc mem */
+
+	/* set up some name stuff */
+	dev->board_name = this_board->name;
+
+	/* grab our IRQ */
+	irq = 0;
+	if (this_board->IRQbits != 0) {	/* board support IRQ */
+		irq = it->options[1];
+		if (irq) {	/* we want to use IRQ */
+			if (((1 << irq) & this_board->IRQbits) == 0) {
+				rt_printk
+					(", IRQ %u is out of allowed range, DISABLING IT",
+					irq);
+				irq = 0;	/* Bad IRQ */
+			} else {
+				if (comedi_request_irq(irq, interrupt_pcl816, 0,
+						"pcl816", dev)) {
+					rt_printk
+						(", unable to allocate IRQ %u, DISABLING IT",
+						irq);
+					irq = 0;	/* Can't use IRQ */
+				} else {
+					rt_printk(", irq=%u", irq);
+				}
+			}
+		}
+	}
+
+	dev->irq = irq;
+	if (irq) {
+		devpriv->irq_free = 1;
+	} /* 1=we have allocated irq */
+	else {
+		devpriv->irq_free = 0;
+	}
+	devpriv->irq_blocked = 0;	/* number of subdevice which use IRQ */
+	devpriv->int816_mode = 0;	/* mode of irq */
+
+#ifdef unused
+	/* grab RTC for DMA operations */
+	devpriv->dma_rtc = 0;
+	if (it->options[2] > 0) {	// we want to use DMA
+		if (RTC_lock == 0) {
+			if (!request_region(RTC_PORT(0), RTC_IO_EXTENT,
+					"pcl816 (RTC)"))
+				goto no_rtc;
+		}
+		devpriv->rtc_iobase = RTC_PORT(0);
+		devpriv->rtc_iosize = RTC_IO_EXTENT;
+		RTC_lock++;
+#ifdef UNTESTED_CODE
+		if (!comedi_request_irq(RTC_IRQ,
+				interrupt_pcl816_ai_mode13_dma_rtc, 0,
+				"pcl816 DMA (RTC)", dev)) {
+			devpriv->dma_rtc = 1;
+			devpriv->rtc_irq = RTC_IRQ;
+			rt_printk(", dma_irq=%u", devpriv->rtc_irq);
+		} else {
+			RTC_lock--;
+			if (RTC_lock == 0) {
+				if (devpriv->rtc_iobase)
+					release_region(devpriv->rtc_iobase,
+						devpriv->rtc_iosize);
+			}
+			devpriv->rtc_iobase = 0;
+			devpriv->rtc_iosize = 0;
+		}
+#else
+		printk("pcl816: RTC code missing");
+#endif
+
+	}
+
+      no_rtc:
+#endif
+	/* grab our DMA */
+	dma = 0;
+	devpriv->dma = dma;
+	if ((devpriv->irq_free == 0) && (devpriv->dma_rtc == 0))
+		goto no_dma;	/* if we haven't IRQ, we can't use DMA */
+
+	if (this_board->DMAbits != 0) {	/* board support DMA */
+		dma = it->options[2];
+		if (dma < 1)
+			goto no_dma;	/* DMA disabled */
+
+		if (((1 << dma) & this_board->DMAbits) == 0) {
+			rt_printk(", DMA is out of allowed range, FAIL!\n");
+			return -EINVAL;	/* Bad DMA */
+		}
+		ret = request_dma(dma, "pcl816");
+		if (ret) {
+			rt_printk(", unable to allocate DMA %u, FAIL!\n", dma);
+			return -EBUSY;	/* DMA isn't free */
+		}
+
+		devpriv->dma = dma;
+		rt_printk(", dma=%u", dma);
+		pages = 2;	/* we need 16KB */
+		devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
+
+		if (!devpriv->dmabuf[0]) {
+			rt_printk(", unable to allocate DMA buffer, FAIL!\n");
+			/* maybe experiment with try_to_free_pages() will help .... */
+			return -EBUSY;	/* no buffer :-( */
+		}
+		devpriv->dmapages[0] = pages;
+		devpriv->hwdmaptr[0] = virt_to_bus((void *)devpriv->dmabuf[0]);
+		devpriv->hwdmasize[0] = (1 << pages) * PAGE_SIZE;
+		//rt_printk("%d %d %ld, ",devpriv->dmapages[0],devpriv->hwdmasize[0],PAGE_SIZE);
+
+		if (devpriv->dma_rtc == 0) {	// we must do duble buff :-(
+			devpriv->dmabuf[1] = __get_dma_pages(GFP_KERNEL, pages);
+			if (!devpriv->dmabuf[1]) {
+				rt_printk
+					(", unable to allocate DMA buffer, FAIL!\n");
+				return -EBUSY;
+			}
+			devpriv->dmapages[1] = pages;
+			devpriv->hwdmaptr[1] =
+				virt_to_bus((void *)devpriv->dmabuf[1]);
+			devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;
+		}
+	}
+
+      no_dma:
+
+/*  if (this_board->n_aochan > 0)
+    subdevs[1] = COMEDI_SUBD_AO;
+  if (this_board->n_dichan > 0)
+    subdevs[2] = COMEDI_SUBD_DI;
+  if (this_board->n_dochan > 0)
+    subdevs[3] = COMEDI_SUBD_DO;
+*/
+	if ((ret = alloc_subdevices(dev, 1)) < 0)
+		return ret;
+
+	s = dev->subdevices + 0;
+	if (this_board->n_aichan > 0) {
+		s->type = COMEDI_SUBD_AI;
+		devpriv->sub_ai = s;
+		dev->read_subdev = s;
+		s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
+		s->n_chan = this_board->n_aichan;
+		s->subdev_flags |= SDF_DIFF;
+		//printk (", %dchans DIFF DAC - %d", s->n_chan, i);
+		s->maxdata = this_board->ai_maxdata;
+		s->len_chanlist = this_board->ai_chanlist;
+		s->range_table = this_board->ai_range_type;
+		s->cancel = pcl816_ai_cancel;
+		s->do_cmdtest = pcl816_ai_cmdtest;
+		s->do_cmd = pcl816_ai_cmd;
+		s->poll = pcl816_ai_poll;
+		s->insn_read = pcl816_ai_insn_read;
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+#if 0
+case COMEDI_SUBD_AO:
+	s->subdev_flags = SDF_WRITABLE | SDF_GROUND;
+	s->n_chan = this_board->n_aochan;
+	s->maxdata = this_board->ao_maxdata;
+	s->len_chanlist = this_board->ao_chanlist;
+	s->range_table = this_board->ao_range_type;
+	break;
+
+case COMEDI_SUBD_DI:
+	s->subdev_flags = SDF_READABLE;
+	s->n_chan = this_board->n_dichan;
+	s->maxdata = 1;
+	s->len_chanlist = this_board->n_dichan;
+	s->range_table = &range_digital;
+	break;
+
+case COMEDI_SUBD_DO:
+	s->subdev_flags = SDF_WRITABLE;
+	s->n_chan = this_board->n_dochan;
+	s->maxdata = 1;
+	s->len_chanlist = this_board->n_dochan;
+	s->range_table = &range_digital;
+	break;
+#endif
+
+	pcl816_reset(dev);
+
+	rt_printk("\n");
+
+	return 0;
+}
+
+/*
+==============================================================================
+  Removes device
+ */
+static int pcl816_detach(comedi_device * dev)
+{
+	DEBUG(rt_printk("comedi%d: pcl816: remove\n", dev->minor);
+		)
+		free_resources(dev);
+#ifdef unused
+	if (devpriv->dma_rtc)
+		RTC_lock--;
+#endif
+	return 0;
+}