ni_at_a2150.c revision 70265d24e3404fe798b6edd55a02016b1edb49d7
1/*
2    comedi/drivers/ni_at_a2150.c
3    Driver for National Instruments AT-A2150 boards
4    Copyright (C) 2001, 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
5
6    COMEDI - Linux Control and Measurement Device Interface
7    Copyright (C) 2000 David A. Schleef <ds@schleef.org>
8
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 2 of the License, or
12    (at your option) any later version.
13
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22
23************************************************************************
24*/
25/*
26Driver: ni_at_a2150
27Description: National Instruments AT-A2150
28Author: Frank Mori Hess
29Status: works
30Devices: [National Instruments] AT-A2150C (at_a2150c), AT-2150S (at_a2150s)
31
32If you want to ac couple the board's inputs, use AREF_OTHER.
33
34Configuration options:
35  [0] - I/O port base address
36  [1] - IRQ (optional, required for timed conversions)
37  [2] - DMA (optional, required for timed conversions)
38
39*/
40/*
41Yet another driver for obsolete hardware brought to you by Frank Hess.
42Testing and debugging help provided by Dave Andruczyk.
43
44This driver supports the boards:
45
46AT-A2150C
47AT-A2150S
48
49The only difference is their master clock frequencies.
50
51Options:
52	[0] - base io address
53	[1] - irq
54	[2] - dma channel
55
56References (from ftp://ftp.natinst.com/support/manuals):
57
58	   320360.pdf  AT-A2150 User Manual
59
60TODO:
61
62analog level triggering
63TRIG_WAKE_EOS
64
65*/
66
67#include "../comedidev.h"
68
69#include <linux/ioport.h>
70#include <asm/dma.h>
71
72#include "8253.h"
73#include "comedi_fc.h"
74
75#define A2150_SIZE           28
76#define A2150_DMA_BUFFER_SIZE	0xff00	/*  size in bytes of dma buffer */
77
78/* #define A2150_DEBUG     enable debugging code */
79#undef A2150_DEBUG		/*  disable debugging code */
80
81/* Registers and bits */
82#define CONFIG_REG		0x0
83#define   CHANNEL_BITS(x)		((x) & 0x7)
84#define   CHANNEL_MASK		0x7
85#define   CLOCK_SELECT_BITS(x)		(((x) & 0x3) << 3)
86#define   CLOCK_DIVISOR_BITS(x)		(((x) & 0x3) << 5)
87#define   CLOCK_MASK		(0xf << 3)
88#define   ENABLE0_BIT		0x80	/*  enable (don't internally ground) channels 0 and 1 */
89#define   ENABLE1_BIT		0x100	/*  enable (don't internally ground) channels 2 and 3 */
90#define   AC0_BIT		0x200	/*  ac couple channels 0,1 */
91#define   AC1_BIT		0x400	/*  ac couple channels 2,3 */
92#define   APD_BIT		0x800	/*  analog power down */
93#define   DPD_BIT		0x1000	/*  digital power down */
94#define TRIGGER_REG		0x2	/*  trigger config register */
95#define   POST_TRIGGER_BITS		0x2
96#define   DELAY_TRIGGER_BITS		0x3
97#define   HW_TRIG_EN		0x10	/*  enable hardware trigger */
98#define FIFO_START_REG		0x6	/*  software start aquistion trigger */
99#define FIFO_RESET_REG		0x8	/*  clears fifo + fifo flags */
100#define FIFO_DATA_REG		0xa	/*  read data */
101#define DMA_TC_CLEAR_REG		0xe	/*  clear dma terminal count interrupt */
102#define STATUS_REG		0x12	/*  read only */
103#define   FNE_BIT		0x1	/*  fifo not empty */
104#define   OVFL_BIT		0x8	/*  fifo overflow */
105#define   EDAQ_BIT		0x10	/*  end of aquisition interrupt */
106#define   DCAL_BIT		0x20	/*  offset calibration in progress */
107#define   INTR_BIT		0x40	/*  interrupt has occured */
108#define   DMA_TC_BIT		0x80	/*  dma terminal count interrupt has occured */
109#define   ID_BITS(x)	(((x) >> 8) & 0x3)
110#define IRQ_DMA_CNTRL_REG		0x12	/*  write only */
111#define   DMA_CHAN_BITS(x)		((x) & 0x7)	/*  sets dma channel */
112#define   DMA_EN_BIT		0x8	/*  enables dma */
113#define   IRQ_LVL_BITS(x)		(((x) & 0xf) << 4)	/*  sets irq level */
114#define   FIFO_INTR_EN_BIT		0x100	/*  enable fifo interrupts */
115#define   FIFO_INTR_FHF_BIT		0x200	/*  interrupt fifo half full */
116#define   DMA_INTR_EN_BIT 		0x800	/*  enable interrupt on dma terminal count */
117#define   DMA_DEM_EN_BIT	0x1000	/*  enables demand mode dma */
118#define I8253_BASE_REG		0x14
119#define I8253_MODE_REG		0x17
120#define   HW_COUNT_DISABLE		0x30	/*  disable hardware counting of conversions */
121
122struct a2150_board {
123	const char *name;
124	int clock[4];		/*  master clock periods, in nanoseconds */
125	int num_clocks;		/*  number of available master clock speeds */
126	int ai_speed;		/*  maximum conversion rate in nanoseconds */
127};
128
129/* analog input range */
130static const struct comedi_lrange range_a2150 = {
131	1,
132	{
133			RANGE(-2.828, 2.828),
134		}
135};
136
137/* enum must match board indices */
138enum { a2150_c, a2150_s };
139static const struct a2150_board a2150_boards[] = {
140	{
141	      name:	"at-a2150c",
142	      clock:	{31250, 22676, 20833, 19531},
143	      num_clocks:4,
144	      ai_speed:19531,
145		},
146	{
147	      name:	"at-a2150s",
148	      clock:	{62500, 50000, 41667, 0},
149	      num_clocks:3,
150	      ai_speed:41667,
151		},
152};
153
154/*
155 * Useful for shorthand access to the particular board structure
156 */
157#define thisboard ((const struct a2150_board *)dev->board_ptr)
158
159struct a2150_private {
160
161	volatile unsigned int count;	/* number of data points left to be taken */
162	unsigned int dma;	/*  dma channel */
163	s16 *dma_buffer;	/*  dma buffer */
164	unsigned int dma_transfer_size;	/*  size in bytes of dma transfers */
165	int irq_dma_bits;	/*  irq/dma register bits */
166	int config_bits;	/*  config register bits */
167};
168
169
170#define devpriv ((struct a2150_private *)dev->private)
171
172static int a2150_attach(struct comedi_device * dev, struct comedi_devconfig * it);
173static int a2150_detach(struct comedi_device * dev);
174static int a2150_cancel(struct comedi_device * dev, struct comedi_subdevice * s);
175
176static struct comedi_driver driver_a2150 = {
177      driver_name:"ni_at_a2150",
178      module:THIS_MODULE,
179      attach:a2150_attach,
180      detach:a2150_detach,
181};
182
183static irqreturn_t a2150_interrupt(int irq, void *d);
184static int a2150_ai_cmdtest(struct comedi_device * dev, struct comedi_subdevice * s,
185	struct comedi_cmd * cmd);
186static int a2150_ai_cmd(struct comedi_device * dev, struct comedi_subdevice * s);
187static int a2150_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
188	struct comedi_insn * insn, unsigned int * data);
189static int a2150_get_timing(struct comedi_device * dev, unsigned int *period,
190	int flags);
191static int a2150_probe(struct comedi_device * dev);
192static int a2150_set_chanlist(struct comedi_device * dev, unsigned int start_channel,
193	unsigned int num_channels);
194/*
195 * A convenient macro that defines init_module() and cleanup_module(),
196 * as necessary.
197 */
198COMEDI_INITCLEANUP(driver_a2150);
199
200#ifdef A2150_DEBUG
201
202static void ni_dump_regs(struct comedi_device * dev)
203{
204	rt_printk("config bits 0x%x\n", devpriv->config_bits);
205	rt_printk("irq dma bits 0x%x\n", devpriv->irq_dma_bits);
206	rt_printk("status bits 0x%x\n", inw(dev->iobase + STATUS_REG));
207}
208
209#endif
210
211/* interrupt service routine */
212static irqreturn_t a2150_interrupt(int irq, void *d)
213{
214	int i;
215	int status;
216	unsigned long flags;
217	struct comedi_device *dev = d;
218	struct comedi_subdevice *s = dev->read_subdev;
219	struct comedi_async *async;
220	struct comedi_cmd *cmd;
221	unsigned int max_points, num_points, residue, leftover;
222	short dpnt;
223	static const int sample_size = sizeof(devpriv->dma_buffer[0]);
224
225	if (dev->attached == 0) {
226		comedi_error(dev, "premature interrupt");
227		return IRQ_HANDLED;
228	}
229	/*  initialize async here to make sure s is not NULL */
230	async = s->async;
231	async->events = 0;
232	cmd = &async->cmd;
233
234	status = inw(dev->iobase + STATUS_REG);
235
236	if ((status & INTR_BIT) == 0) {
237		comedi_error(dev, "spurious interrupt");
238		return IRQ_NONE;
239	}
240
241	if (status & OVFL_BIT) {
242		comedi_error(dev, "fifo overflow");
243		a2150_cancel(dev, s);
244		async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
245	}
246
247	if ((status & DMA_TC_BIT) == 0) {
248		comedi_error(dev, "caught non-dma interrupt?  Aborting.");
249		a2150_cancel(dev, s);
250		async->events |= COMEDI_CB_ERROR | COMEDI_CB_EOA;
251		comedi_event(dev, s);
252		return IRQ_HANDLED;
253	}
254
255	flags = claim_dma_lock();
256	disable_dma(devpriv->dma);
257	/* clear flip-flop to make sure 2-byte registers for
258	 * count and address get set correctly */
259	clear_dma_ff(devpriv->dma);
260
261	/*  figure out how many points to read */
262	max_points = devpriv->dma_transfer_size / sample_size;
263	/* residue is the number of points left to be done on the dma
264	 * transfer.  It should always be zero at this point unless
265	 * the stop_src is set to external triggering.
266	 */
267	residue = get_dma_residue(devpriv->dma) / sample_size;
268	num_points = max_points - residue;
269	if (devpriv->count < num_points && cmd->stop_src == TRIG_COUNT)
270		num_points = devpriv->count;
271
272	/*  figure out how many points will be stored next time */
273	leftover = 0;
274	if (cmd->stop_src == TRIG_NONE) {
275		leftover = devpriv->dma_transfer_size / sample_size;
276	} else if (devpriv->count > max_points) {
277		leftover = devpriv->count - max_points;
278		if (leftover > max_points)
279			leftover = max_points;
280	}
281	/* there should only be a residue if collection was stopped by having
282	 * the stop_src set to an external trigger, in which case there
283	 * will be no more data
284	 */
285	if (residue)
286		leftover = 0;
287
288	for (i = 0; i < num_points; i++) {
289		/* write data point to comedi buffer */
290		dpnt = devpriv->dma_buffer[i];
291		/*  convert from 2's complement to unsigned coding */
292		dpnt ^= 0x8000;
293		cfc_write_to_buffer(s, dpnt);
294		if (cmd->stop_src == TRIG_COUNT) {
295			if (--devpriv->count == 0) {	/* end of acquisition */
296				a2150_cancel(dev, s);
297				async->events |= COMEDI_CB_EOA;
298				break;
299			}
300		}
301	}
302	/*  re-enable  dma */
303	if (leftover) {
304		set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
305		set_dma_count(devpriv->dma, leftover * sample_size);
306		enable_dma(devpriv->dma);
307	}
308	release_dma_lock(flags);
309
310	async->events |= COMEDI_CB_BLOCK;
311
312	comedi_event(dev, s);
313
314	/* clear interrupt */
315	outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
316
317	return IRQ_HANDLED;
318}
319
320/* probes board type, returns offset */
321static int a2150_probe(struct comedi_device * dev)
322{
323	int status = inw(dev->iobase + STATUS_REG);
324	return ID_BITS(status);
325}
326
327static int a2150_attach(struct comedi_device * dev, struct comedi_devconfig * it)
328{
329	struct comedi_subdevice *s;
330	unsigned long iobase = it->options[0];
331	unsigned int irq = it->options[1];
332	unsigned int dma = it->options[2];
333	static const int timeout = 2000;
334	int i;
335
336	printk("comedi%d: %s: io 0x%lx", dev->minor, driver_a2150.driver_name,
337		iobase);
338	if (irq) {
339		printk(", irq %u", irq);
340	} else {
341		printk(", no irq");
342	}
343	if (dma) {
344		printk(", dma %u", dma);
345	} else {
346		printk(", no dma");
347	}
348	printk("\n");
349
350	/* allocate and initialize dev->private */
351	if (alloc_private(dev, sizeof(struct a2150_private)) < 0)
352		return -ENOMEM;
353
354	if (iobase == 0) {
355		printk(" io base address required\n");
356		return -EINVAL;
357	}
358
359	/* check if io addresses are available */
360	if (!request_region(iobase, A2150_SIZE, driver_a2150.driver_name)) {
361		printk(" I/O port conflict\n");
362		return -EIO;
363	}
364	dev->iobase = iobase;
365
366	/* grab our IRQ */
367	if (irq) {
368		/*  check that irq is supported */
369		if (irq < 3 || irq == 8 || irq == 13 || irq > 15) {
370			printk(" invalid irq line %u\n", irq);
371			return -EINVAL;
372		}
373		if (comedi_request_irq(irq, a2150_interrupt, 0,
374				driver_a2150.driver_name, dev)) {
375			printk("unable to allocate irq %u\n", irq);
376			return -EINVAL;
377		}
378		devpriv->irq_dma_bits |= IRQ_LVL_BITS(irq);
379		dev->irq = irq;
380	}
381	/*  initialize dma */
382	if (dma) {
383		if (dma == 4 || dma > 7) {
384			printk(" invalid dma channel %u\n", dma);
385			return -EINVAL;
386		}
387		if (request_dma(dma, driver_a2150.driver_name)) {
388			printk(" failed to allocate dma channel %u\n", dma);
389			return -EINVAL;
390		}
391		devpriv->dma = dma;
392		devpriv->dma_buffer =
393			kmalloc(A2150_DMA_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
394		if (devpriv->dma_buffer == NULL)
395			return -ENOMEM;
396
397		disable_dma(dma);
398		set_dma_mode(dma, DMA_MODE_READ);
399
400		devpriv->irq_dma_bits |= DMA_CHAN_BITS(dma);
401	}
402
403	dev->board_ptr = a2150_boards + a2150_probe(dev);
404	dev->board_name = thisboard->name;
405
406	if (alloc_subdevices(dev, 1) < 0)
407		return -ENOMEM;
408
409	/* analog input subdevice */
410	s = dev->subdevices + 0;
411	dev->read_subdev = s;
412	s->type = COMEDI_SUBD_AI;
413	s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_OTHER | SDF_CMD_READ;
414	s->n_chan = 4;
415	s->len_chanlist = 4;
416	s->maxdata = 0xffff;
417	s->range_table = &range_a2150;
418	s->do_cmd = a2150_ai_cmd;
419	s->do_cmdtest = a2150_ai_cmdtest;
420	s->insn_read = a2150_ai_rinsn;
421	s->cancel = a2150_cancel;
422
423	/* need to do this for software counting of completed conversions, to
424	 * prevent hardware count from stopping aquisition */
425	outw(HW_COUNT_DISABLE, dev->iobase + I8253_MODE_REG);
426
427	/*  set card's irq and dma levels */
428	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
429
430	/*  reset and sync adc clock circuitry */
431	outw_p(DPD_BIT | APD_BIT, dev->iobase + CONFIG_REG);
432	outw_p(DPD_BIT, dev->iobase + CONFIG_REG);
433	/*  initialize configuration register */
434	devpriv->config_bits = 0;
435	outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
436	/*  wait until offset calibration is done, then enable analog inputs */
437	for (i = 0; i < timeout; i++) {
438		if ((DCAL_BIT & inw(dev->iobase + STATUS_REG)) == 0)
439			break;
440		comedi_udelay(1000);
441	}
442	if (i == timeout) {
443		printk(" timed out waiting for offset calibration to complete\n");
444		return -ETIME;
445	}
446	devpriv->config_bits |= ENABLE0_BIT | ENABLE1_BIT;
447	outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
448
449	return 0;
450};
451
452static int a2150_detach(struct comedi_device * dev)
453{
454	printk("comedi%d: %s: remove\n", dev->minor, driver_a2150.driver_name);
455
456	/* only free stuff if it has been allocated by _attach */
457	if (dev->iobase) {
458		/*  put board in power-down mode */
459		outw(APD_BIT | DPD_BIT, dev->iobase + CONFIG_REG);
460		release_region(dev->iobase, A2150_SIZE);
461	}
462
463	if (dev->irq)
464		comedi_free_irq(dev->irq, dev);
465	if (devpriv) {
466		if (devpriv->dma)
467			free_dma(devpriv->dma);
468		if (devpriv->dma_buffer)
469			kfree(devpriv->dma_buffer);
470	}
471
472	return 0;
473};
474
475static int a2150_cancel(struct comedi_device * dev, struct comedi_subdevice * s)
476{
477	/*  disable dma on card */
478	devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
479	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
480
481	/*  disable computer's dma */
482	disable_dma(devpriv->dma);
483
484	/*  clear fifo and reset triggering circuitry */
485	outw(0, dev->iobase + FIFO_RESET_REG);
486
487	return 0;
488}
489
490static int a2150_ai_cmdtest(struct comedi_device * dev, struct comedi_subdevice * s,
491	struct comedi_cmd * cmd)
492{
493	int err = 0;
494	int tmp;
495	int startChan;
496	int i;
497
498	/* step 1: make sure trigger sources are trivially valid */
499
500	tmp = cmd->start_src;
501	cmd->start_src &= TRIG_NOW | TRIG_EXT;
502	if (!cmd->start_src || tmp != cmd->start_src)
503		err++;
504
505	tmp = cmd->scan_begin_src;
506	cmd->scan_begin_src &= TRIG_TIMER;
507	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
508		err++;
509
510	tmp = cmd->convert_src;
511	cmd->convert_src &= TRIG_NOW;
512	if (!cmd->convert_src || tmp != cmd->convert_src)
513		err++;
514
515	tmp = cmd->scan_end_src;
516	cmd->scan_end_src &= TRIG_COUNT;
517	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
518		err++;
519
520	tmp = cmd->stop_src;
521	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
522	if (!cmd->stop_src || tmp != cmd->stop_src)
523		err++;
524
525	if (err)
526		return 1;
527
528	/* step 2: make sure trigger sources are unique and mutually compatible */
529
530	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
531		err++;
532	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
533		err++;
534
535	if (err)
536		return 2;
537
538	/* step 3: make sure arguments are trivially compatible */
539
540	if (cmd->start_arg != 0) {
541		cmd->start_arg = 0;
542		err++;
543	}
544	if (cmd->convert_src == TRIG_TIMER) {
545		if (cmd->convert_arg < thisboard->ai_speed) {
546			cmd->convert_arg = thisboard->ai_speed;
547			err++;
548		}
549	}
550	if (!cmd->chanlist_len) {
551		cmd->chanlist_len = 1;
552		err++;
553	}
554	if (cmd->scan_end_arg != cmd->chanlist_len) {
555		cmd->scan_end_arg = cmd->chanlist_len;
556		err++;
557	}
558	if (cmd->stop_src == TRIG_COUNT) {
559		if (!cmd->stop_arg) {
560			cmd->stop_arg = 1;
561			err++;
562		}
563	} else {		/* TRIG_NONE */
564		if (cmd->stop_arg != 0) {
565			cmd->stop_arg = 0;
566			err++;
567		}
568	}
569
570	if (err)
571		return 3;
572
573	/* step 4: fix up any arguments */
574
575	if (cmd->scan_begin_src == TRIG_TIMER) {
576		tmp = cmd->scan_begin_arg;
577		a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
578		if (tmp != cmd->scan_begin_arg)
579			err++;
580	}
581
582	if (err)
583		return 4;
584
585	/*  check channel/gain list against card's limitations */
586	if (cmd->chanlist) {
587		startChan = CR_CHAN(cmd->chanlist[0]);
588		for (i = 1; i < cmd->chanlist_len; i++) {
589			if (CR_CHAN(cmd->chanlist[i]) != (startChan + i)) {
590				comedi_error(dev,
591					"entries in chanlist must be consecutive channels, counting upwards\n");
592				err++;
593			}
594		}
595		if (cmd->chanlist_len == 2 && CR_CHAN(cmd->chanlist[0]) == 1) {
596			comedi_error(dev,
597				"length 2 chanlist must be channels 0,1 or channels 2,3");
598			err++;
599		}
600		if (cmd->chanlist_len == 3) {
601			comedi_error(dev,
602				"chanlist must have 1,2 or 4 channels");
603			err++;
604		}
605		if (CR_AREF(cmd->chanlist[0]) != CR_AREF(cmd->chanlist[1]) ||
606			CR_AREF(cmd->chanlist[2]) != CR_AREF(cmd->chanlist[3]))
607		{
608			comedi_error(dev,
609				"channels 0/1 and 2/3 must have the same analog reference");
610			err++;
611		}
612	}
613
614	if (err)
615		return 5;
616
617	return 0;
618}
619
620static int a2150_ai_cmd(struct comedi_device * dev, struct comedi_subdevice * s)
621{
622	struct comedi_async *async = s->async;
623	struct comedi_cmd *cmd = &async->cmd;
624	unsigned long lock_flags;
625	unsigned int old_config_bits = devpriv->config_bits;
626	unsigned int trigger_bits;
627
628	if (!dev->irq || !devpriv->dma) {
629		comedi_error(dev,
630			" irq and dma required, cannot do hardware conversions");
631		return -1;
632	}
633	if (cmd->flags & TRIG_RT) {
634		comedi_error(dev,
635			" dma incompatible with hard real-time interrupt (TRIG_RT), aborting");
636		return -1;
637	}
638	/*  clear fifo and reset triggering circuitry */
639	outw(0, dev->iobase + FIFO_RESET_REG);
640
641	/* setup chanlist */
642	if (a2150_set_chanlist(dev, CR_CHAN(cmd->chanlist[0]),
643			cmd->chanlist_len) < 0)
644		return -1;
645
646	/*  setup ac/dc coupling */
647	if (CR_AREF(cmd->chanlist[0]) == AREF_OTHER)
648		devpriv->config_bits |= AC0_BIT;
649	else
650		devpriv->config_bits &= ~AC0_BIT;
651	if (CR_AREF(cmd->chanlist[2]) == AREF_OTHER)
652		devpriv->config_bits |= AC1_BIT;
653	else
654		devpriv->config_bits &= ~AC1_BIT;
655
656	/*  setup timing */
657	a2150_get_timing(dev, &cmd->scan_begin_arg, cmd->flags);
658
659	/*  send timing, channel, config bits */
660	outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
661
662	/*  initialize number of samples remaining */
663	devpriv->count = cmd->stop_arg * cmd->chanlist_len;
664
665	/*  enable computer's dma */
666	lock_flags = claim_dma_lock();
667	disable_dma(devpriv->dma);
668	/* clear flip-flop to make sure 2-byte registers for
669	 * count and address get set correctly */
670	clear_dma_ff(devpriv->dma);
671	set_dma_addr(devpriv->dma, virt_to_bus(devpriv->dma_buffer));
672	/*  set size of transfer to fill in 1/3 second */
673#define ONE_THIRD_SECOND 333333333
674	devpriv->dma_transfer_size =
675		sizeof(devpriv->dma_buffer[0]) * cmd->chanlist_len *
676		ONE_THIRD_SECOND / cmd->scan_begin_arg;
677	if (devpriv->dma_transfer_size > A2150_DMA_BUFFER_SIZE)
678		devpriv->dma_transfer_size = A2150_DMA_BUFFER_SIZE;
679	if (devpriv->dma_transfer_size < sizeof(devpriv->dma_buffer[0]))
680		devpriv->dma_transfer_size = sizeof(devpriv->dma_buffer[0]);
681	devpriv->dma_transfer_size -=
682		devpriv->dma_transfer_size % sizeof(devpriv->dma_buffer[0]);
683	set_dma_count(devpriv->dma, devpriv->dma_transfer_size);
684	enable_dma(devpriv->dma);
685	release_dma_lock(lock_flags);
686
687	/* clear dma interrupt before enabling it, to try and get rid of that
688	 * one spurious interrupt that has been happening */
689	outw(0x00, dev->iobase + DMA_TC_CLEAR_REG);
690
691	/*  enable dma on card */
692	devpriv->irq_dma_bits |= DMA_INTR_EN_BIT | DMA_EN_BIT;
693	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
694
695	/*  may need to wait 72 sampling periods if timing was changed */
696	i8254_load(dev->iobase + I8253_BASE_REG, 0, 2, 72, 0);
697
698	/*  setup start triggering */
699	trigger_bits = 0;
700	/*  decide if we need to wait 72 periods for valid data */
701	if (cmd->start_src == TRIG_NOW &&
702		(old_config_bits & CLOCK_MASK) !=
703		(devpriv->config_bits & CLOCK_MASK)) {
704		/*  set trigger source to delay trigger */
705		trigger_bits |= DELAY_TRIGGER_BITS;
706	} else {
707		/*  otherwise no delay */
708		trigger_bits |= POST_TRIGGER_BITS;
709	}
710	/*  enable external hardware trigger */
711	if (cmd->start_src == TRIG_EXT) {
712		trigger_bits |= HW_TRIG_EN;
713	} else if (cmd->start_src == TRIG_OTHER) {
714		/*  XXX add support for level/slope start trigger using TRIG_OTHER */
715		comedi_error(dev, "you shouldn't see this?");
716	}
717	/*  send trigger config bits */
718	outw(trigger_bits, dev->iobase + TRIGGER_REG);
719
720	/*  start aquisition for soft trigger */
721	if (cmd->start_src == TRIG_NOW) {
722		outw(0, dev->iobase + FIFO_START_REG);
723	}
724#ifdef A2150_DEBUG
725	ni_dump_regs(dev);
726#endif
727
728	return 0;
729}
730
731static int a2150_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
732	struct comedi_insn * insn, unsigned int * data)
733{
734	unsigned int i, n;
735	static const int timeout = 100000;
736	static const int filter_delay = 36;
737
738	/*  clear fifo and reset triggering circuitry */
739	outw(0, dev->iobase + FIFO_RESET_REG);
740
741	/* setup chanlist */
742	if (a2150_set_chanlist(dev, CR_CHAN(insn->chanspec), 1) < 0)
743		return -1;
744
745	/*  set dc coupling */
746	devpriv->config_bits &= ~AC0_BIT;
747	devpriv->config_bits &= ~AC1_BIT;
748
749	/*  send timing, channel, config bits */
750	outw(devpriv->config_bits, dev->iobase + CONFIG_REG);
751
752	/*  disable dma on card */
753	devpriv->irq_dma_bits &= ~DMA_INTR_EN_BIT & ~DMA_EN_BIT;
754	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
755
756	/*  setup start triggering */
757	outw(0, dev->iobase + TRIGGER_REG);
758
759	/*  start aquisition for soft trigger */
760	outw(0, dev->iobase + FIFO_START_REG);
761
762	/* there is a 35.6 sample delay for data to get through the antialias filter */
763	for (n = 0; n < filter_delay; n++) {
764		for (i = 0; i < timeout; i++) {
765			if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
766				break;
767			comedi_udelay(1);
768		}
769		if (i == timeout) {
770			comedi_error(dev, "timeout");
771			return -ETIME;
772		}
773		inw(dev->iobase + FIFO_DATA_REG);
774	}
775
776	/*  read data */
777	for (n = 0; n < insn->n; n++) {
778		for (i = 0; i < timeout; i++) {
779			if (inw(dev->iobase + STATUS_REG) & FNE_BIT)
780				break;
781			comedi_udelay(1);
782		}
783		if (i == timeout) {
784			comedi_error(dev, "timeout");
785			return -ETIME;
786		}
787#ifdef A2150_DEBUG
788		ni_dump_regs(dev);
789#endif
790		data[n] = inw(dev->iobase + FIFO_DATA_REG);
791#ifdef A2150_DEBUG
792		rt_printk(" data is %i\n", data[n]);
793#endif
794		data[n] ^= 0x8000;
795	}
796
797	/*  clear fifo and reset triggering circuitry */
798	outw(0, dev->iobase + FIFO_RESET_REG);
799
800	return n;
801}
802
803/* sets bits in devpriv->clock_bits to nearest approximation of requested period,
804 * adjusts requested period to actual timing. */
805static int a2150_get_timing(struct comedi_device * dev, unsigned int *period,
806	int flags)
807{
808	int lub, glb, temp;
809	int lub_divisor_shift, lub_index, glb_divisor_shift, glb_index;
810	int i, j;
811
812	/*  initialize greatest lower and least upper bounds */
813	lub_divisor_shift = 3;
814	lub_index = 0;
815	lub = thisboard->clock[lub_index] * (1 << lub_divisor_shift);
816	glb_divisor_shift = 0;
817	glb_index = thisboard->num_clocks - 1;
818	glb = thisboard->clock[glb_index] * (1 << glb_divisor_shift);
819
820	/*  make sure period is in available range */
821	if (*period < glb)
822		*period = glb;
823	if (*period > lub)
824		*period = lub;
825
826	/*  we can multiply period by 1, 2, 4, or 8, using (1 << i) */
827	for (i = 0; i < 4; i++) {
828		/*  there are a maximum of 4 master clocks */
829		for (j = 0; j < thisboard->num_clocks; j++) {
830			/*  temp is the period in nanosec we are evaluating */
831			temp = thisboard->clock[j] * (1 << i);
832			/*  if it is the best match yet */
833			if (temp < lub && temp >= *period) {
834				lub_divisor_shift = i;
835				lub_index = j;
836				lub = temp;
837			}
838			if (temp > glb && temp <= *period) {
839				glb_divisor_shift = i;
840				glb_index = j;
841				glb = temp;
842			}
843		}
844	}
845	flags &= TRIG_ROUND_MASK;
846	switch (flags) {
847	case TRIG_ROUND_NEAREST:
848	default:
849		/*  if least upper bound is better approximation */
850		if (lub - *period < *period - glb) {
851			*period = lub;
852		} else {
853			*period = glb;
854		}
855		break;
856	case TRIG_ROUND_UP:
857		*period = lub;
858		break;
859	case TRIG_ROUND_DOWN:
860		*period = glb;
861		break;
862	}
863
864	/*  set clock bits for config register appropriately */
865	devpriv->config_bits &= ~CLOCK_MASK;
866	if (*period == lub) {
867		devpriv->config_bits |=
868			CLOCK_SELECT_BITS(lub_index) |
869			CLOCK_DIVISOR_BITS(lub_divisor_shift);
870	} else {
871		devpriv->config_bits |=
872			CLOCK_SELECT_BITS(glb_index) |
873			CLOCK_DIVISOR_BITS(glb_divisor_shift);
874	}
875
876	return 0;
877}
878
879static int a2150_set_chanlist(struct comedi_device * dev, unsigned int start_channel,
880	unsigned int num_channels)
881{
882	if (start_channel + num_channels > 4)
883		return -1;
884
885	devpriv->config_bits &= ~CHANNEL_MASK;
886
887	switch (num_channels) {
888	case 1:
889		devpriv->config_bits |= CHANNEL_BITS(0x4 | start_channel);
890		break;
891	case 2:
892		if (start_channel == 0) {
893			devpriv->config_bits |= CHANNEL_BITS(0x2);
894		} else if (start_channel == 2) {
895			devpriv->config_bits |= CHANNEL_BITS(0x3);
896		} else {
897			return -1;
898		}
899		break;
900	case 4:
901		devpriv->config_bits |= CHANNEL_BITS(0x1);
902		break;
903	default:
904		return -1;
905		break;
906	}
907
908	return 0;
909}
910