Staging: comedi: add comedi_test driver

This adds the comedi_test driver to the kernel tree

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

2 files changed, 527 insertions, 0 deletions

diff --git a/drivers/staging/comedi/drivers/Makefile b/drivers/staging/comedi/drivers/Makefile
index 39b1291..95d1f46 100644
--- a/drivers/staging/comedi/drivers/Makefile
+++ b/drivers/staging/comedi/drivers/Makefile
@@ -4,6 +4,7 @@
 # Comedi "helper" modules
 obj-$(CONFIG_COMEDI)			+= comedi_fc.o
 obj-$(CONFIG_COMEDI)			+= comedi_bond.o
+obj-$(CONFIG_COMEDI)			+= comedi_test.o
 
 # Comedi PCI drivers
 obj-$(CONFIG_COMEDI_PCI_DRIVERS)	+= mite.o
diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c
new file mode 100644
index 0000000..356a9e9
--- /dev/null
+++ b/drivers/staging/comedi/drivers/comedi_test.c
@@ -0,0 +1,526 @@
+/*
+    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.
+
+    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: 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 "../comedidev.h"
+
+#include <asm/div64.h>
+
+#include "comedi_fc.h"
+
+/* Board descriptions */
+typedef struct waveform_board_struct {
+	const char *name;
+	int ai_chans;
+	int ai_bits;
+	int have_dio;
+} waveform_board;
+
+#define N_CHANS 8
+
+static const waveform_board waveform_boards[] = {
+	{
+	      name:	"comedi_test",
+	      ai_chans:N_CHANS,
+	      ai_bits:	16,
+	      have_dio:0,
+		},
+};
+
+#define thisboard ((const waveform_board *)dev->board_ptr)
+
+/* Data unique to this driver */
+typedef struct {
+	struct timer_list timer;
+	struct timeval last;	// time at which last timer interrupt occured
+	unsigned int uvolt_amplitude;	// waveform amplitude in microvolts
+	unsigned long usec_period;	// waveform period in microseconds
+	volatile unsigned long usec_current;	// current time (modulo waveform period)
+	volatile unsigned long usec_remainder;	// usec since last scan;
+	volatile unsigned long ai_count;	// number of conversions remaining
+	unsigned int scan_period;	// scan period in usec
+	unsigned int convert_period;	// conversion period in usec
+	volatile unsigned timer_running:1;
+	volatile lsampl_t ao_loopbacks[N_CHANS];
+} waveform_private;
+#define devpriv ((waveform_private *)dev->private)
+
+static int waveform_attach(comedi_device * dev, comedi_devconfig * it);
+static int waveform_detach(comedi_device * dev);
+static comedi_driver driver_waveform = {
+      driver_name:"comedi_test",
+      module:THIS_MODULE,
+      attach:waveform_attach,
+      detach:waveform_detach,
+      board_name:&waveform_boards[0].name,
+      offset:sizeof(waveform_board),
+      num_names:sizeof(waveform_boards) / sizeof(waveform_board),
+};
+
+COMEDI_INITCLEANUP(driver_waveform);
+
+static int waveform_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd);
+static int waveform_ai_cmd(comedi_device * dev, comedi_subdevice * s);
+static int waveform_ai_cancel(comedi_device * dev, comedi_subdevice * s);
+static int waveform_ai_insn_read(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static int waveform_ao_insn_write(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static sampl_t fake_sawtooth(comedi_device * dev, unsigned int range,
+	unsigned long current_time);
+static sampl_t fake_squarewave(comedi_device * dev, unsigned int range,
+	unsigned long current_time);
+static sampl_t fake_flatline(comedi_device * dev, unsigned int range,
+	unsigned long current_time);
+static sampl_t fake_waveform(comedi_device * dev, unsigned int channel,
+	unsigned int range, unsigned long current_time);
+
+static const int nano_per_micro = 1000;	// 1000 nanosec in a microsec
+
+// fake analog input ranges
+static const comedi_lrange waveform_ai_ranges = {
+	2,
+	{
+			BIP_RANGE(10),
+			BIP_RANGE(5),
+		}
+};
+
+/*
+   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)
+{
+	comedi_device *dev = (comedi_device *) arg;
+	comedi_async *async = dev->read_subdev->async;
+	comedi_cmd *cmd = &async->cmd;
+	unsigned int i, j;
+	// all times in microsec
+	unsigned long elapsed_time;
+	unsigned int num_scans;
+	struct timeval now;
+
+	do_gettimeofday(&now);
+
+	elapsed_time =
+		1000000 * (now.tv_sec - devpriv->last.tv_sec) + now.tv_usec -
+		devpriv->last.tv_usec;
+	devpriv->last = now;
+	num_scans =
+		(devpriv->usec_remainder + elapsed_time) / devpriv->scan_period;
+	devpriv->usec_remainder =
+		(devpriv->usec_remainder + elapsed_time) % devpriv->scan_period;
+	async->events = 0;
+
+	for (i = 0; i < num_scans; i++) {
+		for (j = 0; j < cmd->chanlist_len; j++) {
+			cfc_write_to_buffer(dev->read_subdev,
+				fake_waveform(dev, CR_CHAN(cmd->chanlist[j]),
+					CR_RANGE(cmd->chanlist[j]),
+					devpriv->usec_current +
+					i * devpriv->scan_period +
+					j * devpriv->convert_period));
+		}
+		devpriv->ai_count++;
+		if (cmd->stop_src == TRIG_COUNT
+			&& devpriv->ai_count >= cmd->stop_arg) {
+			async->events |= COMEDI_CB_EOA;
+			break;
+		}
+	}
+
+	devpriv->usec_current += elapsed_time;
+	devpriv->usec_current %= devpriv->usec_period;
+
+	if ((async->events & COMEDI_CB_EOA) == 0 && devpriv->timer_running)
+		mod_timer(&devpriv->timer, jiffies + 1);
+	else
+		del_timer(&devpriv->timer);
+
+	comedi_event(dev, dev->read_subdev);
+}
+
+static int waveform_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	comedi_subdevice *s;
+	int amplitude = it->options[0];
+	int period = it->options[1];
+
+	printk("comedi%d: comedi_test: ", dev->minor);
+
+	dev->board_name = thisboard->name;
+
+	if (alloc_private(dev, sizeof(waveform_private)) < 0)
+		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;
+
+	printk("%i microvolt, %li microsecond waveform ",
+		devpriv->uvolt_amplitude, devpriv->usec_period);
+	dev->n_subdevices = 2;
+	if (alloc_subdevices(dev, dev->n_subdevices) < 0)
+		return -ENOMEM;
+
+	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 = thisboard->ai_chans;
+	s->maxdata = (1 << thisboard->ai_bits) - 1;
+	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_WRITEABLE | SDF_GROUND;
+	s->n_chan = thisboard->ai_chans;
+	s->maxdata = (1 << thisboard->ai_bits) - 1;
+	s->range_table = &waveform_ai_ranges;
+	s->len_chanlist = s->n_chan * 2;
+	s->insn_write = waveform_ao_insn_write;
+	s->do_cmd = 0;
+	s->do_cmdtest = 0;
+	s->cancel = 0;
+	{
+		/* Our default loopback value is just a 0V flatline */
+		int i;
+		for (i = 0; i < s->n_chan; i++)
+			devpriv->ao_loopbacks[i] = s->maxdata / 2;
+	}
+
+	init_timer(&(devpriv->timer));
+	devpriv->timer.function = waveform_ai_interrupt;
+	devpriv->timer.data = (unsigned long)dev;
+
+	printk("attached\n");
+
+	return 1;
+}
+
+static int waveform_detach(comedi_device * dev)
+{
+	printk("comedi%d: comedi_test: remove\n", dev->minor);
+
+	if (dev->private) {
+		waveform_ai_cancel(dev, dev->read_subdev);
+	}
+
+	return 0;
+}
+
+static int waveform_ai_cmdtest(comedi_device * dev, comedi_subdevice * s,
+	comedi_cmd * cmd)
+{
+	int err = 0;
+	int tmp;
+
+	/* 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_TIMER;
+	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
+		err++;
+
+	tmp = cmd->convert_src;
+	cmd->convert_src &= TRIG_NOW | TRIG_TIMER;
+	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->convert_src != TRIG_NOW && cmd->convert_src != TRIG_TIMER)
+		err++;
+	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
+		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->convert_src == TRIG_NOW) {
+		if (cmd->convert_arg != 0) {
+			cmd->convert_arg = 0;
+			err++;
+		}
+	}
+	if (cmd->scan_begin_src == TRIG_TIMER) {
+		if (cmd->scan_begin_arg < nano_per_micro) {
+			cmd->scan_begin_arg = nano_per_micro;
+			err++;
+		}
+		if (cmd->convert_src == TRIG_TIMER &&
+			cmd->scan_begin_arg <
+			cmd->convert_arg * cmd->chanlist_len) {
+			cmd->scan_begin_arg =
+				cmd->convert_arg * cmd->chanlist_len;
+			err++;
+		}
+	}
+	// XXX these checks are generic and should go in core if not there already
+	if (!cmd->chanlist_len) {
+		cmd->chanlist_len = 1;
+		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->scan_begin_src == TRIG_TIMER) {
+		tmp = cmd->scan_begin_arg;
+		// round to nearest microsec
+		cmd->scan_begin_arg =
+			nano_per_micro * ((tmp +
+				(nano_per_micro / 2)) / nano_per_micro);
+		if (tmp != cmd->scan_begin_arg)
+			err++;
+	}
+	if (cmd->convert_src == TRIG_TIMER) {
+		tmp = cmd->convert_arg;
+		// round to nearest microsec
+		cmd->convert_arg =
+			nano_per_micro * ((tmp +
+				(nano_per_micro / 2)) / nano_per_micro);
+		if (tmp != cmd->convert_arg)
+			err++;
+	}
+
+	if (err)
+		return 4;
+
+	return 0;
+}
+
+static int waveform_ai_cmd(comedi_device * dev, comedi_subdevice * s)
+{
+	comedi_cmd *cmd = &s->async->cmd;
+
+	if (cmd->flags & TRIG_RT) {
+		comedi_error(dev,
+			"commands at RT priority not supported in this driver");
+		return -1;
+	}
+
+	devpriv->timer_running = 1;
+	devpriv->ai_count = 0;
+	devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro;
+
+	if (cmd->convert_src == TRIG_NOW)
+		devpriv->convert_period = 0;
+	else if (cmd->convert_src == TRIG_TIMER)
+		devpriv->convert_period = cmd->convert_arg / nano_per_micro;
+	else {
+		comedi_error(dev, "bug setting conversion period");
+		return -1;
+	}
+
+	do_gettimeofday(&devpriv->last);
+	devpriv->usec_current = devpriv->last.tv_usec % devpriv->usec_period;
+	devpriv->usec_remainder = 0;
+
+	devpriv->timer.expires = jiffies + 1;
+	add_timer(&devpriv->timer);
+	return 0;
+}
+
+static int waveform_ai_cancel(comedi_device * dev, comedi_subdevice * s)
+{
+	devpriv->timer_running = 0;
+	del_timer(&devpriv->timer);
+	return 0;
+}
+
+static sampl_t fake_sawtooth(comedi_device * dev, unsigned int range_index,
+	unsigned long current_time)
+{
+	comedi_subdevice *s = dev->read_subdev;
+	unsigned int offset = s->maxdata / 2;
+	u64 value;
+	const 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 sampl_t fake_squarewave(comedi_device * dev, unsigned int range_index,
+	unsigned long current_time)
+{
+	comedi_subdevice *s = dev->read_subdev;
+	unsigned int offset = s->maxdata / 2;
+	u64 value;
+	const 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 sampl_t fake_flatline(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 sampl_t fake_waveform(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);
+		break;
+	case SQUARE_CHAN:
+		return fake_squarewave(dev, range, current_time);
+		break;
+	default:
+		break;
+	}
+
+	return fake_flatline(dev, range, current_time);
+}
+
+static int waveform_ai_insn_read(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	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(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i, chan = CR_CHAN(insn->chanspec);
+
+	for (i = 0; i < insn->n; i++)
+		devpriv->ao_loopbacks[chan] = data[i];
+
+	return insn->n;
+}