diff options
| -rw-r--r-- | drivers/staging/comedi/drivers/comedi_test.c | 212 |
1 files changed, 209 insertions, 3 deletions
diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index 14a0b62..4ab1866 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -57,7 +57,8 @@ #define N_CHANS 8 enum waveform_state_bits { - WAVEFORM_AI_RUNNING = 0 + WAVEFORM_AI_RUNNING, + WAVEFORM_AO_RUNNING }; /* Data unique to this driver */ @@ -70,6 +71,9 @@ struct waveform_private { unsigned long state_bits; unsigned int ai_scan_period; /* AI scan period in usec */ unsigned int ai_convert_period; /* AI conversion period in usec */ + struct timer_list ao_timer; /* timer for AO commands */ + u64 ao_last_scan_time; /* time of previous AO scan in usec */ + unsigned int ao_scan_period; /* AO scan period in usec */ unsigned short ao_loopbacks[N_CHANS]; }; @@ -417,6 +421,201 @@ static int waveform_ai_insn_read(struct comedi_device *dev, return insn->n; } +/* + * This is the background routine to handle AO commands, scheduled by + * a timer mechanism. + */ +static void waveform_ao_timer(unsigned long arg) +{ + struct comedi_device *dev = (struct comedi_device *)arg; + struct waveform_private *devpriv = dev->private; + struct comedi_subdevice *s = dev->write_subdev; + struct comedi_async *async = s->async; + struct comedi_cmd *cmd = &async->cmd; + u64 now; + u64 scans_since; + unsigned int scans_avail = 0; + + /* check command is still active */ + if (!test_bit(WAVEFORM_AO_RUNNING, &devpriv->state_bits)) + return; + + /* determine number of scan periods since last time */ + now = ktime_to_us(ktime_get()); + scans_since = now - devpriv->ao_last_scan_time; + do_div(scans_since, devpriv->ao_scan_period); + if (scans_since) { + unsigned int i; + + /* determine scans in buffer, limit to scans to do this time */ + scans_avail = comedi_nscans_left(s, 0); + if (scans_avail > scans_since) + scans_avail = scans_since; + if (scans_avail) { + /* skip all but the last scan to save processing time */ + if (scans_avail > 1) { + unsigned int skip_bytes, nbytes; + + skip_bytes = + comedi_samples_to_bytes(s, cmd->scan_end_arg * + (scans_avail - 1)); + nbytes = comedi_buf_read_alloc(s, skip_bytes); + comedi_buf_read_free(s, nbytes); + comedi_inc_scan_progress(s, nbytes); + if (nbytes < skip_bytes) { + /* unexpected underrun! (cancelled?) */ + async->events |= COMEDI_CB_OVERFLOW; + goto underrun; + } + } + /* output the last scan */ + for (i = 0; i < cmd->scan_end_arg; i++) { + unsigned int chan = CR_CHAN(cmd->chanlist[i]); + + if (comedi_buf_read_samples(s, + &devpriv-> + ao_loopbacks[chan], + 1) == 0) { + /* unexpected underrun! (cancelled?) */ + async->events |= COMEDI_CB_OVERFLOW; + goto underrun; + } + } + /* advance time of last scan */ + devpriv->ao_last_scan_time += + (u64)scans_avail * devpriv->ao_scan_period; + } + } + if (cmd->stop_src == TRIG_COUNT && async->scans_done >= cmd->stop_arg) { + async->events |= COMEDI_CB_EOA; + } else if (scans_avail < scans_since) { + async->events |= COMEDI_CB_OVERFLOW; + } else { + unsigned int time_inc = devpriv->ao_last_scan_time + + devpriv->ao_scan_period - now; + + mod_timer(&devpriv->ao_timer, + jiffies + usecs_to_jiffies(time_inc)); + } + +underrun: + comedi_handle_events(dev, s); +} + +static int waveform_ao_inttrig_start(struct comedi_device *dev, + struct comedi_subdevice *s, + unsigned int trig_num) +{ + struct waveform_private *devpriv = dev->private; + struct comedi_async *async = s->async; + struct comedi_cmd *cmd = &async->cmd; + + if (trig_num != cmd->start_arg) + return -EINVAL; + + async->inttrig = NULL; + + devpriv->ao_last_scan_time = ktime_to_us(ktime_get()); + devpriv->ao_timer.expires = + jiffies + usecs_to_jiffies(devpriv->ao_scan_period); + + /* mark command as active */ + smp_mb__before_atomic(); + set_bit(WAVEFORM_AO_RUNNING, &devpriv->state_bits); + smp_mb__after_atomic(); + add_timer(&devpriv->ao_timer); + + return 1; +} + +static int waveform_ao_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_INT); + err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); + err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW); + 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->stop_src); + + /* Step 2b : and mutually compatible */ + + if (err) + return 2; + + /* Step 3: check if arguments are trivially valid */ + + err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, + NSEC_PER_USEC); + err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0); + 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 /* cmd->stop_src == TRIG_NONE */ + err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0); + + if (err) + return 3; + + /* step 4: fix up any arguments */ + + /* round scan_begin_arg to nearest microsecond */ + arg = cmd->scan_begin_arg; + arg = min(arg, rounddown(UINT_MAX, (unsigned int)NSEC_PER_USEC)); + arg = NSEC_PER_USEC * DIV_ROUND_CLOSEST(arg, NSEC_PER_USEC); + err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg); + + if (err) + return 4; + + return 0; +} + +static int waveform_ao_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->ao_scan_period = cmd->scan_begin_arg / NSEC_PER_USEC; + s->async->inttrig = waveform_ao_inttrig_start; + return 0; +} + +static int waveform_ao_cancel(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + struct waveform_private *devpriv = dev->private; + + s->async->inttrig = NULL; + /* mark command as no longer active */ + clear_bit(WAVEFORM_AO_RUNNING, &devpriv->state_bits); + smp_mb__after_atomic(); + /* cannot call del_timer_sync() as may be called from timer routine */ + del_timer(&devpriv->ao_timer); + return 0; +} + static int waveform_ao_insn_write(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) @@ -475,18 +674,23 @@ static int waveform_attach(struct comedi_device *dev, dev->write_subdev = s; /* analog output subdevice (loopback) */ s->type = COMEDI_SUBD_AO; - s->subdev_flags = SDF_WRITABLE | SDF_GROUND; + s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_CMD_WRITE; s->n_chan = N_CHANS; s->maxdata = 0xffff; s->range_table = &waveform_ai_ranges; + s->len_chanlist = s->n_chan; s->insn_write = waveform_ao_insn_write; s->insn_read = waveform_ai_insn_read; /* do same as AI insn_read */ + s->do_cmd = waveform_ao_cmd; + s->do_cmdtest = waveform_ao_cmdtest; + s->cancel = waveform_ao_cancel; /* 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->ai_timer, waveform_ai_timer, (unsigned long)dev); + setup_timer(&devpriv->ao_timer, waveform_ao_timer, (unsigned long)dev); dev_info(dev->class_dev, "%s: %u microvolt, %u microsecond waveform attached\n", @@ -500,8 +704,10 @@ static void waveform_detach(struct comedi_device *dev) { struct waveform_private *devpriv = dev->private; - if (devpriv) + if (devpriv) { del_timer_sync(&devpriv->ai_timer); + del_timer_sync(&devpriv->ao_timer); + } } static struct comedi_driver waveform_driver = { |