--- /dev/null
+/*
+ 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");
Code Review / kvmfornfv.git / blobdiff