1 files changed, 456 insertions, 0 deletions

diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c
new file mode 100644
index 000000000..80d613c0f
--- /dev/null
+++ b/drivers/staging/comedi/drivers/comedi_test.c
@@ -0,0 +1,456 @@
+/*
+    comedi/drivers/comedi_test.c
+
+    Generates fake waveform signals that can be read through
+    the command interface.  It does _not_ read from any board;
+    it just generates deterministic waveforms.
+    Useful for various testing purposes.
+
+    Copyright (C) 2002 Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>
+    Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+
+    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.
+*/
+/*
+Driver: comedi_test
+Description: generates fake waveforms
+Author: Joachim Wuttke <Joachim.Wuttke@icn.siemens.de>, Frank Mori Hess
+  <fmhess@users.sourceforge.net>, ds
+Devices:
+Status: works
+Updated: Sat, 16 Mar 2002 17:34:48 -0800
+
+This driver is mainly for testing purposes, but can also be used to
+generate sample waveforms on systems that don't have data acquisition
+hardware.
+
+Configuration options:
+  [0] - Amplitude in microvolts for fake waveforms (default 1 volt)
+  [1] - Period in microseconds for fake waveforms (default 0.1 sec)
+
+Generates a sawtooth wave on channel 0, square wave on channel 1, additional
+waveforms could be added to other channels (currently they return flatline
+zero volts).
+
+*/
+
+#include <linux/module.h>
+#include "../comedidev.h"
+
+#include <asm/div64.h>
+
+#include <linux/timer.h>
+#include <linux/ktime.h>
+
+#define N_CHANS 8
+
+enum waveform_state_bits {
+	WAVEFORM_AI_RUNNING = 0
+};
+
+/* Data unique to this driver */
+struct waveform_private {
+	struct timer_list timer;
+	ktime_t last;	/* time last timer interrupt occurred */
+	unsigned int uvolt_amplitude;	/* waveform amplitude in microvolts */
+	unsigned long usec_period;	/* waveform period in microseconds */
+	unsigned long usec_current;	/* current time (mod waveform period) */
+	unsigned long usec_remainder;	/* usec since last scan */
+	unsigned long state_bits;
+	unsigned int scan_period;	/* scan period in usec */
+	unsigned int convert_period;	/* conversion period in usec */
+	unsigned int ao_loopbacks[N_CHANS];
+};
+
+/* 1000 nanosec in a microsec */
+static const int nano_per_micro = 1000;
+
+/* fake analog input ranges */
+static const struct comedi_lrange waveform_ai_ranges = {
+	2, {
+		BIP_RANGE(10),
+		BIP_RANGE(5)
+	}
+};
+
+static unsigned short fake_sawtooth(struct comedi_device *dev,
+				    unsigned int range_index,
+				    unsigned long current_time)
+{
+	struct waveform_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	unsigned int offset = s->maxdata / 2;
+	u64 value;
+	const struct comedi_krange *krange =
+	    &s->range_table->range[range_index];
+	u64 binary_amplitude;
+
+	binary_amplitude = s->maxdata;
+	binary_amplitude *= devpriv->uvolt_amplitude;
+	do_div(binary_amplitude, krange->max - krange->min);
+
+	current_time %= devpriv->usec_period;
+	value = current_time;
+	value *= binary_amplitude * 2;
+	do_div(value, devpriv->usec_period);
+	value -= binary_amplitude;	/* get rid of sawtooth's dc offset */
+
+	return offset + value;
+}
+
+static unsigned short fake_squarewave(struct comedi_device *dev,
+				      unsigned int range_index,
+				      unsigned long current_time)
+{
+	struct waveform_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	unsigned int offset = s->maxdata / 2;
+	u64 value;
+	const struct comedi_krange *krange =
+	    &s->range_table->range[range_index];
+	current_time %= devpriv->usec_period;
+
+	value = s->maxdata;
+	value *= devpriv->uvolt_amplitude;
+	do_div(value, krange->max - krange->min);
+
+	if (current_time < devpriv->usec_period / 2)
+		value *= -1;
+
+	return offset + value;
+}
+
+static unsigned short fake_flatline(struct comedi_device *dev,
+				    unsigned int range_index,
+				    unsigned long current_time)
+{
+	return dev->read_subdev->maxdata / 2;
+}
+
+/* generates a different waveform depending on what channel is read */
+static unsigned short fake_waveform(struct comedi_device *dev,
+				    unsigned int channel, unsigned int range,
+				    unsigned long current_time)
+{
+	enum {
+		SAWTOOTH_CHAN,
+		SQUARE_CHAN,
+	};
+	switch (channel) {
+	case SAWTOOTH_CHAN:
+		return fake_sawtooth(dev, range, current_time);
+	case SQUARE_CHAN:
+		return fake_squarewave(dev, range, current_time);
+	default:
+		break;
+	}
+
+	return fake_flatline(dev, range, current_time);
+}
+
+/*
+   This is the background routine used to generate arbitrary data.
+   It should run in the background; therefore it is scheduled by
+   a timer mechanism.
+*/
+static void waveform_ai_interrupt(unsigned long arg)
+{
+	struct comedi_device *dev = (struct comedi_device *)arg;
+	struct waveform_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	struct comedi_async *async = s->async;
+	struct comedi_cmd *cmd = &async->cmd;
+	unsigned int i, j;
+	/* all times in microsec */
+	unsigned long elapsed_time;
+	unsigned int num_scans;
+	ktime_t now;
+
+	/* check command is still active */
+	if (!test_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits))
+		return;
+
+	now = ktime_get();
+
+	elapsed_time = ktime_to_us(ktime_sub(now, devpriv->last));
+	devpriv->last = now;
+	num_scans =
+	    (devpriv->usec_remainder + elapsed_time) / devpriv->scan_period;
+	devpriv->usec_remainder =
+	    (devpriv->usec_remainder + elapsed_time) % devpriv->scan_period;
+
+	num_scans = comedi_nscans_left(s, num_scans);
+	for (i = 0; i < num_scans; i++) {
+		for (j = 0; j < cmd->chanlist_len; j++) {
+			unsigned short sample;
+
+			sample = fake_waveform(dev, CR_CHAN(cmd->chanlist[j]),
+					       CR_RANGE(cmd->chanlist[j]),
+					       devpriv->usec_current +
+						   i * devpriv->scan_period +
+						   j * devpriv->convert_period);
+			comedi_buf_write_samples(s, &sample, 1);
+		}
+	}
+
+	devpriv->usec_current += elapsed_time;
+	devpriv->usec_current %= devpriv->usec_period;
+
+	if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg)
+		async->events |= COMEDI_CB_EOA;
+	else
+		mod_timer(&devpriv->timer, jiffies + 1);
+
+	comedi_handle_events(dev, s);
+}
+
+static int waveform_ai_cmdtest(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_cmd *cmd)
+{
+	int err = 0;
+	unsigned int arg;
+
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= comedi_check_trigger_src(&cmd->convert_src,
+					TRIG_NOW | TRIG_TIMER);
+	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
+
+	if (err)
+		return 1;
+
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= comedi_check_trigger_is_unique(cmd->convert_src);
+	err |= comedi_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
+
+	if (err)
+		return 2;
+
+	/* Step 3: check if arguments are trivially valid */
+
+	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
+
+	if (cmd->convert_src == TRIG_NOW)
+		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
+
+	if (cmd->scan_begin_src == TRIG_TIMER) {
+		err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
+						    nano_per_micro);
+		if (cmd->convert_src == TRIG_TIMER) {
+			err |= comedi_check_trigger_arg_min(&cmd->
+							    scan_begin_arg,
+							    cmd->convert_arg *
+							    cmd->chanlist_len);
+		}
+	}
+
+	err |= comedi_check_trigger_arg_min(&cmd->chanlist_len, 1);
+	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
+					   cmd->chanlist_len);
+
+	if (cmd->stop_src == TRIG_COUNT)
+		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
+	else	/* TRIG_NONE */
+		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
+
+	if (err)
+		return 3;
+
+	/* step 4: fix up any arguments */
+
+	if (cmd->scan_begin_src == TRIG_TIMER) {
+		arg = cmd->scan_begin_arg;
+		/* round to nearest microsec */
+		arg = nano_per_micro *
+		      ((arg + (nano_per_micro / 2)) / nano_per_micro);
+		err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
+	}
+	if (cmd->convert_src == TRIG_TIMER) {
+		arg = cmd->convert_arg;
+		/* round to nearest microsec */
+		arg = nano_per_micro *
+		      ((arg + (nano_per_micro / 2)) / nano_per_micro);
+		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
+	}
+
+	if (err)
+		return 4;
+
+	return 0;
+}
+
+static int waveform_ai_cmd(struct comedi_device *dev,
+			   struct comedi_subdevice *s)
+{
+	struct waveform_private *devpriv = dev->private;
+	struct comedi_cmd *cmd = &s->async->cmd;
+
+	if (cmd->flags & CMDF_PRIORITY) {
+		dev_err(dev->class_dev,
+			"commands at RT priority not supported in this driver\n");
+		return -1;
+	}
+
+	devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro;
+
+	if (cmd->convert_src == TRIG_NOW)
+		devpriv->convert_period = 0;
+	else	/* TRIG_TIMER */
+		devpriv->convert_period = cmd->convert_arg / nano_per_micro;
+
+	devpriv->last = ktime_get();
+	devpriv->usec_current =
+		((u32)ktime_to_us(devpriv->last)) % devpriv->usec_period;
+	devpriv->usec_remainder = 0;
+
+	devpriv->timer.expires = jiffies + 1;
+	/* mark command as active */
+	smp_mb__before_atomic();
+	set_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits);
+	smp_mb__after_atomic();
+	add_timer(&devpriv->timer);
+	return 0;
+}
+
+static int waveform_ai_cancel(struct comedi_device *dev,
+			      struct comedi_subdevice *s)
+{
+	struct waveform_private *devpriv = dev->private;
+
+	/* mark command as no longer active */
+	clear_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits);
+	smp_mb__after_atomic();
+	/* cannot call del_timer_sync() as may be called from timer routine */
+	del_timer(&devpriv->timer);
+	return 0;
+}
+
+static int waveform_ai_insn_read(struct comedi_device *dev,
+				 struct comedi_subdevice *s,
+				 struct comedi_insn *insn, unsigned int *data)
+{
+	struct waveform_private *devpriv = dev->private;
+	int i, chan = CR_CHAN(insn->chanspec);
+
+	for (i = 0; i < insn->n; i++)
+		data[i] = devpriv->ao_loopbacks[chan];
+
+	return insn->n;
+}
+
+static int waveform_ao_insn_write(struct comedi_device *dev,
+				  struct comedi_subdevice *s,
+				  struct comedi_insn *insn, unsigned int *data)
+{
+	struct waveform_private *devpriv = dev->private;
+	int i, chan = CR_CHAN(insn->chanspec);
+
+	for (i = 0; i < insn->n; i++)
+		devpriv->ao_loopbacks[chan] = data[i];
+
+	return insn->n;
+}
+
+static int waveform_attach(struct comedi_device *dev,
+			   struct comedi_devconfig *it)
+{
+	struct waveform_private *devpriv;
+	struct comedi_subdevice *s;
+	int amplitude = it->options[0];
+	int period = it->options[1];
+	int i;
+	int ret;
+
+	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
+	if (!devpriv)
+		return -ENOMEM;
+
+	/* set default amplitude and period */
+	if (amplitude <= 0)
+		amplitude = 1000000;	/* 1 volt */
+	if (period <= 0)
+		period = 100000;	/* 0.1 sec */
+
+	devpriv->uvolt_amplitude = amplitude;
+	devpriv->usec_period = period;
+
+	ret = comedi_alloc_subdevices(dev, 2);
+	if (ret)
+		return ret;
+
+	s = &dev->subdevices[0];
+	dev->read_subdev = s;
+	/* analog input subdevice */
+	s->type = COMEDI_SUBD_AI;
+	s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
+	s->n_chan = N_CHANS;
+	s->maxdata = 0xffff;
+	s->range_table = &waveform_ai_ranges;
+	s->len_chanlist = s->n_chan * 2;
+	s->insn_read = waveform_ai_insn_read;
+	s->do_cmd = waveform_ai_cmd;
+	s->do_cmdtest = waveform_ai_cmdtest;
+	s->cancel = waveform_ai_cancel;
+
+	s = &dev->subdevices[1];
+	dev->write_subdev = s;
+	/* analog output subdevice (loopback) */
+	s->type = COMEDI_SUBD_AO;
+	s->subdev_flags = SDF_WRITABLE | SDF_GROUND;
+	s->n_chan = N_CHANS;
+	s->maxdata = 0xffff;
+	s->range_table = &waveform_ai_ranges;
+	s->insn_write = waveform_ao_insn_write;
+
+	/* Our default loopback value is just a 0V flatline */
+	for (i = 0; i < s->n_chan; i++)
+		devpriv->ao_loopbacks[i] = s->maxdata / 2;
+
+	setup_timer(&devpriv->timer, waveform_ai_interrupt,
+		    (unsigned long)dev);
+
+	dev_info(dev->class_dev,
+		 "%s: %i microvolt, %li microsecond waveform attached\n",
+		 dev->board_name,
+		 devpriv->uvolt_amplitude, devpriv->usec_period);
+
+	return 0;
+}
+
+static void waveform_detach(struct comedi_device *dev)
+{
+	struct waveform_private *devpriv = dev->private;
+
+	if (devpriv)
+		del_timer_sync(&devpriv->timer);
+}
+
+static struct comedi_driver waveform_driver = {
+	.driver_name	= "comedi_test",
+	.module		= THIS_MODULE,
+	.attach		= waveform_attach,
+	.detach		= waveform_detach,
+};
+module_comedi_driver(waveform_driver);
+
+MODULE_AUTHOR("Comedi http://www.comedi.org");
+MODULE_DESCRIPTION("Comedi low-level driver");
+MODULE_LICENSE("GPL");