1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * comedi/drivers/dt2814.c
4 * Hardware driver for Data Translation DT2814
5 *
6 * COMEDI - Linux Control and Measurement Device Interface
7 * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
8 */
9/*
10 * Driver: dt2814
11 * Description: Data Translation DT2814
12 * Author: ds
13 * Status: complete
14 * Devices: [Data Translation] DT2814 (dt2814)
15 *
16 * Configuration options:
17 * [0] - I/O port base address
18 * [1] - IRQ
19 *
20 * This card has 16 analog inputs multiplexed onto a 12 bit ADC.  There
21 * is a minimally useful onboard clock.  The base frequency for the
22 * clock is selected by jumpers, and the clock divider can be selected
23 * via programmed I/O.  Unfortunately, the clock divider can only be
24 * a power of 10, from 1 to 10^7, of which only 3 or 4 are useful.  In
25 * addition, the clock does not seem to be very accurate.
26 */
27
28#include <linux/module.h>
29#include <linux/interrupt.h>
30#include <linux/comedi/comedidev.h>
31#include <linux/delay.h>
32
33#define DT2814_CSR 0
34#define DT2814_DATA 1
35
36/*
37 * flags
38 */
39
40#define DT2814_FINISH 0x80
41#define DT2814_ERR 0x40
42#define DT2814_BUSY 0x20
43#define DT2814_ENB 0x10
44#define DT2814_CHANMASK 0x0f
45
46#define DT2814_TIMEOUT 10
47#define DT2814_MAX_SPEED 100000	/* Arbitrary 10 khz limit */
48
49static int dt2814_ai_notbusy(struct comedi_device *dev,
50			     struct comedi_subdevice *s,
51			     struct comedi_insn *insn,
52			     unsigned long context)
53{
54	unsigned int status;
55
56	status = inb(dev->iobase + DT2814_CSR);
57	if (context)
58		*(unsigned int *)context = status;
59	if (status & DT2814_BUSY)
60		return -EBUSY;
61	return 0;
62}
63
64static int dt2814_ai_clear(struct comedi_device *dev)
65{
66	unsigned int status = 0;
67	int ret;
68
69	/* Wait until not busy and get status register value. */
70	ret = comedi_timeout(dev, NULL, NULL, dt2814_ai_notbusy,
71			     (unsigned long)&status);
72	if (ret)
73		return ret;
74
75	if (status & (DT2814_FINISH | DT2814_ERR)) {
76		/*
77		 * There unread data, or the error flag is set.
78		 * Read the data register twice to clear the condition.
79		 */
80		inb(dev->iobase + DT2814_DATA);
81		inb(dev->iobase + DT2814_DATA);
82	}
83	return 0;
84}
85
86static int dt2814_ai_eoc(struct comedi_device *dev,
87			 struct comedi_subdevice *s,
88			 struct comedi_insn *insn,
89			 unsigned long context)
90{
91	unsigned int status;
92
93	status = inb(dev->iobase + DT2814_CSR);
94	if (status & DT2814_FINISH)
95		return 0;
96	return -EBUSY;
97}
98
99static int dt2814_ai_insn_read(struct comedi_device *dev,
100			       struct comedi_subdevice *s,
101			       struct comedi_insn *insn, unsigned int *data)
102{
103	int n, hi, lo;
104	int chan;
105	int ret;
106
107	dt2814_ai_clear(dev);	/* clear stale data or error */
108	for (n = 0; n < insn->n; n++) {
109		chan = CR_CHAN(insn->chanspec);
110
111		outb(chan, dev->iobase + DT2814_CSR);
112
113		ret = comedi_timeout(dev, s, insn, dt2814_ai_eoc, 0);
114		if (ret)
115			return ret;
116
117		hi = inb(dev->iobase + DT2814_DATA);
118		lo = inb(dev->iobase + DT2814_DATA);
119
120		data[n] = (hi << 4) | (lo >> 4);
121	}
122
123	return n;
124}
125
126static int dt2814_ns_to_timer(unsigned int *ns, unsigned int flags)
127{
128	int i;
129	unsigned int f;
130
131	/* XXX ignores flags */
132
133	f = 10000;		/* ns */
134	for (i = 0; i < 8; i++) {
135		if ((2 * (*ns)) < (f * 11))
136			break;
137		f *= 10;
138	}
139
140	*ns = f;
141
142	return i;
143}
144
145static int dt2814_ai_cmdtest(struct comedi_device *dev,
146			     struct comedi_subdevice *s, struct comedi_cmd *cmd)
147{
148	int err = 0;
149	unsigned int arg;
150
151	/* Step 1 : check if triggers are trivially valid */
152
153	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
154	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
155	err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW);
156	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
157	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
158
159	if (err)
160		return 1;
161
162	/* Step 2a : make sure trigger sources are unique */
163
164	err |= comedi_check_trigger_is_unique(cmd->stop_src);
165
166	/* Step 2b : and mutually compatible */
167
168	if (err)
169		return 2;
170
171	/* Step 3: check if arguments are trivially valid */
172
173	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
174
175	err |= comedi_check_trigger_arg_max(&cmd->scan_begin_arg, 1000000000);
176	err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
177					    DT2814_MAX_SPEED);
178
179	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
180					   cmd->chanlist_len);
181
182	if (cmd->stop_src == TRIG_COUNT)
183		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 2);
184	else	/* TRIG_NONE */
185		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
186
187	if (err)
188		return 3;
189
190	/* step 4: fix up any arguments */
191
192	arg = cmd->scan_begin_arg;
193	dt2814_ns_to_timer(&arg, cmd->flags);
194	err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
195
196	if (err)
197		return 4;
198
199	return 0;
200}
201
202static int dt2814_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
203{
204	struct comedi_cmd *cmd = &s->async->cmd;
205	int chan;
206	int trigvar;
207
208	dt2814_ai_clear(dev);	/* clear stale data or error */
209	trigvar = dt2814_ns_to_timer(&cmd->scan_begin_arg, cmd->flags);
210
211	chan = CR_CHAN(cmd->chanlist[0]);
212
213	outb(chan | DT2814_ENB | (trigvar << 5), dev->iobase + DT2814_CSR);
214
215	return 0;
216}
217
218static int dt2814_ai_cancel(struct comedi_device *dev,
219			    struct comedi_subdevice *s)
220{
221	unsigned int status;
222	unsigned long flags;
223
224	spin_lock_irqsave(&dev->spinlock, flags);
225	status = inb(dev->iobase + DT2814_CSR);
226	if (status & DT2814_ENB) {
227		/*
228		 * Clear the timed trigger enable bit.
229		 *
230		 * Note: turning off timed mode triggers another
231		 * sample.  This will be mopped up by the calls to
232		 * dt2814_ai_clear().
233		 */
234		outb(status & DT2814_CHANMASK, dev->iobase + DT2814_CSR);
235	}
236	spin_unlock_irqrestore(&dev->spinlock, flags);
237	return 0;
238}
239
240static irqreturn_t dt2814_interrupt(int irq, void *d)
241{
242	struct comedi_device *dev = d;
243	struct comedi_subdevice *s = dev->read_subdev;
244	struct comedi_async *async;
245	unsigned int lo, hi;
246	unsigned short data;
247	unsigned int status;
248
249	if (!dev->attached) {
250		dev_err(dev->class_dev, "spurious interrupt\n");
251		return IRQ_HANDLED;
252	}
253
254	async = s->async;
255
256	spin_lock(&dev->spinlock);
257
258	status = inb(dev->iobase + DT2814_CSR);
259	if (!(status & DT2814_ENB)) {
260		/* Timed acquisition not enabled.  Nothing to do. */
261		spin_unlock(&dev->spinlock);
262		return IRQ_HANDLED;
263	}
264
265	if (!(status & (DT2814_FINISH | DT2814_ERR))) {
266		/* Spurious interrupt? */
267		spin_unlock(&dev->spinlock);
268		return IRQ_HANDLED;
269	}
270
271	/* Read data or clear error. */
272	hi = inb(dev->iobase + DT2814_DATA);
273	lo = inb(dev->iobase + DT2814_DATA);
274
275	data = (hi << 4) | (lo >> 4);
276
277	if (status & DT2814_ERR) {
278		async->events |= COMEDI_CB_ERROR;
279	} else {
280		comedi_buf_write_samples(s, &data, 1);
281		if (async->cmd.stop_src == TRIG_COUNT &&
282		    async->scans_done >=  async->cmd.stop_arg) {
283			async->events |= COMEDI_CB_EOA;
284		}
285	}
286	if (async->events & COMEDI_CB_CANCEL_MASK) {
287		/*
288		 * Disable timed mode.
289		 *
290		 * Note: turning off timed mode triggers another
291		 * sample.  This will be mopped up by the calls to
292		 * dt2814_ai_clear().
293		 */
294		outb(status & DT2814_CHANMASK, dev->iobase + DT2814_CSR);
295	}
296
297	spin_unlock(&dev->spinlock);
298
299	comedi_handle_events(dev, s);
300	return IRQ_HANDLED;
301}
302
303static int dt2814_attach(struct comedi_device *dev, struct comedi_devconfig *it)
304{
305	struct comedi_subdevice *s;
306	int ret;
307
308	ret = comedi_request_region(dev, it->options[0], 0x2);
309	if (ret)
310		return ret;
311
312	outb(0, dev->iobase + DT2814_CSR);
313	if (dt2814_ai_clear(dev)) {
314		dev_err(dev->class_dev, "reset error (fatal)\n");
315		return -EIO;
316	}
317
318	if (it->options[1]) {
319		ret = request_irq(it->options[1], dt2814_interrupt, 0,
320				  dev->board_name, dev);
321		if (ret == 0)
322			dev->irq = it->options[1];
323	}
324
325	ret = comedi_alloc_subdevices(dev, 1);
326	if (ret)
327		return ret;
328
329	s = &dev->subdevices[0];
330	s->type = COMEDI_SUBD_AI;
331	s->subdev_flags = SDF_READABLE | SDF_GROUND;
332	s->n_chan = 16;		/* XXX */
333	s->insn_read = dt2814_ai_insn_read;
334	s->maxdata = 0xfff;
335	s->range_table = &range_unknown;	/* XXX */
336	if (dev->irq) {
337		dev->read_subdev = s;
338		s->subdev_flags |= SDF_CMD_READ;
339		s->len_chanlist = 1;
340		s->do_cmd = dt2814_ai_cmd;
341		s->do_cmdtest = dt2814_ai_cmdtest;
342		s->cancel = dt2814_ai_cancel;
343	}
344
345	return 0;
346}
347
348static void dt2814_detach(struct comedi_device *dev)
349{
350	if (dev->irq) {
351		/*
352		 * An extra conversion triggered on termination of an
353		 * asynchronous command may still be in progress.  Wait for
354		 * it to finish and clear the data or error status.
355		 */
356		dt2814_ai_clear(dev);
357	}
358	comedi_legacy_detach(dev);
359}
360
361static struct comedi_driver dt2814_driver = {
362	.driver_name	= "dt2814",
363	.module		= THIS_MODULE,
364	.attach		= dt2814_attach,
365	.detach		= dt2814_detach,
366};
367module_comedi_driver(dt2814_driver);
368
369MODULE_AUTHOR("Comedi https://www.comedi.org");
370MODULE_DESCRIPTION("Comedi low-level driver");
371MODULE_LICENSE("GPL");
372