staging: comedi: usbduxsigma: tidy up analog output command support

Rename the (*do_cmdtest) and (*do_cmd) functions so they have namespace
associated with the driver. Rename the local variable used for the
private data pointer.

Move all the command argument initialization and testing into the
(*do_cmdtest) function. That function is always called by the comedi
core before the (*do_cmd) function. The only thing the (*do_cmd) function
should have to do is setup the channel list, initialize the counter for
the conversion, then either start the conversion (submit the urbs) or
set the trigger to start the conversion.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/usbduxsigma.c

@@ -930,18 +930,23 @@ static int usbduxsigma_ao_inttrig(struct comedi_device *dev,
 	return 1;
 }
 
-static int usbdux_ao_cmdtest(struct comedi_device *dev,
-			     struct comedi_subdevice *s,
-			     struct comedi_cmd *cmd)
+static int usbduxsigma_ao_cmdtest(struct comedi_device *dev,
+				  struct comedi_subdevice *s,
+				  struct comedi_cmd *cmd)
 {
+	struct usbduxsigma_private *devpriv = dev->private;
 	int err = 0;
+	int high_speed;
 	unsigned int flags;
 
+	/* high speed conversions are not used yet */
+	high_speed = 0; 	/* (devpriv->high_speed) */
+
 	/* Step 1 : check if triggers are trivially valid */
 
 	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
 
-	if (0) {		/* (this_usbduxsub->high_speed) */
+	if (high_speed) {
 		/*
 		 * start immediately a new scan
 		 * the sampling rate is set by the coversion rate
@@ -957,8 +962,10 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
 	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
-	if (err)
+	if (err) {
+		up(&devpriv->sem);
 		return 1;
+	}
 
 	/* Step 2a : make sure trigger sources are unique */
 
@@ -997,81 +1004,83 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 	if (err)
 		return 3;
 
-	return 0;
-}
-
-static int usbdux_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
-{
-	struct usbduxsigma_private *this_usbduxsub = dev->private;
-	struct comedi_cmd *cmd = &s->async->cmd;
-	unsigned int chan, gain;
-	int i, ret;
+	/* Step 4: fix up any arguments */
 
-	down(&this_usbduxsub->sem);
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
-	for (i = 0; i < cmd->chanlist_len; ++i) {
-		chan = CR_CHAN(cmd->chanlist[i]);
-		gain = CR_RANGE(cmd->chanlist[i]);
-		this_usbduxsub->dac_commands[i] = chan;
-	}
-
-	/* we count in steps of 1ms (125us) */
-	/* 125us mode not used yet */
-	if (0) {		/* (this_usbduxsub->high_speed) */
-		/* 125us */
+	/* we count in timer steps */
+	if (high_speed) {
 		/* timing of the conversion itself: every 125 us */
-		this_usbduxsub->ao_timer = cmd->convert_arg / 125000;
+		devpriv->ao_timer = cmd->convert_arg / 125000;
 	} else {
-		/* 1ms */
-		/* timing of the scan: we get all channels at once */
-		this_usbduxsub->ao_timer = cmd->scan_begin_arg / 1000000;
-		if (this_usbduxsub->ao_timer < 1) {
-			up(&this_usbduxsub->sem);
-			return -EINVAL;
-		}
+		/*
+		 * timing of the scan: every 1ms
+		 * we get all channels at once
+		 */
+		devpriv->ao_timer = cmd->scan_begin_arg / 1000000;
+		if (devpriv->ao_timer < 1)
+			err |= -EINVAL;
 	}
-	this_usbduxsub->ao_counter = this_usbduxsub->ao_timer;
 
 	if (cmd->stop_src == TRIG_COUNT) {
-		/* not continuous */
-		/* counter */
-		/* high speed also scans everything at once */
-		if (0) {	/* (this_usbduxsub->high_speed) */
-			this_usbduxsub->ao_sample_count =
-			    (cmd->stop_arg) * (cmd->scan_end_arg);
+		/* not continuous, use counter */
+		if (high_speed) {
+			/* high speed also scans everything at once */
+			devpriv->ao_sample_count = cmd->stop_arg *
+						   cmd->scan_end_arg;
 		} else {
-			/* there's no scan as the scan has been */
-			/* perf inside the FX2 */
-			/* data arrives as one packet */
-			this_usbduxsub->ao_sample_count = cmd->stop_arg;
+			/*
+			 * There's no scan as the scan has been
+			 * handled inside the FX2. Data arrives as
+			 * one packet.
+			 */
+			devpriv->ao_sample_count = cmd->stop_arg;
 		}
-		this_usbduxsub->ao_continuous = 0;
+		devpriv->ao_continuous = 0;
 	} else {
 		/* continuous acquisition */
-		this_usbduxsub->ao_continuous = 1;
-		this_usbduxsub->ao_sample_count = 0;
+		devpriv->ao_continuous = 1;
+		devpriv->ao_sample_count = 0;
 	}
 
+	if (err)
+		return 4;
+
+	return 0;
+}
+
+static int usbduxsigma_ao_cmd(struct comedi_device *dev,
+			      struct comedi_subdevice *s)
+{
+	struct usbduxsigma_private *devpriv = dev->private;
+	struct comedi_cmd *cmd = &s->async->cmd;
+	int ret;
+	int i;
+
+	down(&devpriv->sem);
+
+	/* set current channel of the running acquisition to zero */
+	s->async->cur_chan = 0;
+	for (i = 0; i < cmd->chanlist_len; ++i)
+		devpriv->dac_commands[i] = CR_CHAN(cmd->chanlist[i]);
+
+	devpriv->ao_counter = devpriv->ao_timer;
+
 	if (cmd->start_src == TRIG_NOW) {
 		/* enable this acquisition operation */
-		ret = usbduxsigma_submit_urbs(dev, this_usbduxsub->urbOut,
-					      this_usbduxsub->numOfOutBuffers,
-					      0);
+		ret = usbduxsigma_submit_urbs(dev, devpriv->urbOut,
+					      devpriv->numOfOutBuffers, 0);
 		if (ret < 0) {
-			up(&this_usbduxsub->sem);
+			up(&devpriv->sem);
 			return ret;
 		}
-		this_usbduxsub->ao_cmd_running = 1;
 		s->async->inttrig = NULL;
-	} else {
-		/* TRIG_INT */
-		/* submit the urbs later */
-		/* wait for an internal signal */
+		devpriv->ao_cmd_running = 1;
+	} else {	/* TRIG_INT */
+		/* wait for an internal signal and submit the urbs later */
 		s->async->inttrig = usbduxsigma_ao_inttrig;
 	}
 
-	up(&this_usbduxsub->sem);
+	up(&devpriv->sem);
+
 	return 0;
 }
 
@@ -1461,8 +1470,8 @@ static int usbduxsigma_attach_common(struct comedi_device *dev)
 	s->range_table	= &range_unipolar2_5;
 	s->insn_write	= usbdux_ao_insn_write;
 	s->insn_read	= usbdux_ao_insn_read;
-	s->do_cmdtest	= usbdux_ao_cmdtest;
-	s->do_cmd	= usbdux_ao_cmd;
+	s->do_cmdtest	= usbduxsigma_ao_cmdtest;
+	s->do_cmd	= usbduxsigma_ao_cmd;
 	s->cancel	= usbdux_ao_cancel;
 
 	/* Digital I/O subdevice */