diff options
Diffstat (limited to 'drivers/staging/comedi/drivers/comedi_test.c')
| -rw-r--r-- | drivers/staging/comedi/drivers/comedi_test.c | 63 |
1 files changed, 34 insertions, 29 deletions
diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index 00c03df72523..e56525a1c8f3 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -52,18 +52,23 @@ zero volts). #include "comedi_fc.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; - struct timeval last; /* time last timer interrupt occurred */ + 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 ai_count; /* number of conversions remaining */ + 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]; @@ -164,36 +169,29 @@ static void waveform_ai_interrupt(unsigned long arg) { struct comedi_device *dev = (struct comedi_device *)arg; struct waveform_private *devpriv = dev->private; - struct comedi_async *async = dev->read_subdev->async; + 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; - struct timeval now; - bool stopping = false; + ktime_t now; + + /* check command is still active */ + if (!test_bit(WAVEFORM_AI_RUNNING, &devpriv->state_bits)) + return; - do_gettimeofday(&now); + now = ktime_get(); - elapsed_time = - 1000000 * (now.tv_sec - devpriv->last.tv_sec) + now.tv_usec - - devpriv->last.tv_usec; + 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; - if (cmd->stop_src == TRIG_COUNT) { - unsigned int remaining = cmd->stop_arg - devpriv->ai_count; - - if (num_scans >= remaining) { - /* about to finish */ - num_scans = remaining; - stopping = true; - } - } - + 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; @@ -203,20 +201,19 @@ static void waveform_ai_interrupt(unsigned long arg) devpriv->usec_current + i * devpriv->scan_period + j * devpriv->convert_period); - cfc_write_to_buffer(dev->read_subdev, sample); + comedi_buf_write_samples(s, &sample, 1); } } - devpriv->ai_count += i; devpriv->usec_current += elapsed_time; devpriv->usec_current %= devpriv->usec_period; - if (stopping) + 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_event(dev, dev->read_subdev); + comedi_handle_events(dev, s); } static int waveform_ai_cmdtest(struct comedi_device *dev, @@ -308,7 +305,6 @@ static int waveform_ai_cmd(struct comedi_device *dev, return -1; } - devpriv->ai_count = 0; devpriv->scan_period = cmd->scan_begin_arg / nano_per_micro; if (cmd->convert_src == TRIG_NOW) @@ -316,11 +312,16 @@ static int waveform_ai_cmd(struct comedi_device *dev, else /* TRIG_TIMER */ devpriv->convert_period = cmd->convert_arg / nano_per_micro; - do_gettimeofday(&devpriv->last); - devpriv->usec_current = devpriv->last.tv_usec % devpriv->usec_period; + 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; } @@ -330,7 +331,11 @@ static int waveform_ai_cancel(struct comedi_device *dev, { struct waveform_private *devpriv = dev->private; - del_timer_sync(&devpriv->timer); + /* 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; } @@ -405,7 +410,7 @@ 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_WRITEABLE | SDF_GROUND; + s->subdev_flags = SDF_WRITABLE | SDF_GROUND; s->n_chan = N_CHANS; s->maxdata = 0xffff; s->range_table = &waveform_ai_ranges; @@ -432,7 +437,7 @@ static void waveform_detach(struct comedi_device *dev) struct waveform_private *devpriv = dev->private; if (devpriv) - waveform_ai_cancel(dev, dev->read_subdev); + del_timer_sync(&devpriv->timer); } static struct comedi_driver waveform_driver = { |