staging: comedi: drivers: move comedi_async 'cur_chan' tracking into the core

The commedi_async 'cur_chan' member is used to track the current position
in the chanlist for a scan. Currently only a couple comedi drivers use
this member.

For aeshtetics, move the 'cur_chan' tracking into the core for non-SDF_PACKED
subdevices. The 'cur_chan' will be updated after reading or writing samples
to the async buffer by comedi_inc_scan_progress(). All non-SDF_PACKED subdevices
will then automatiaclly track the 'cur_chan'.

Some of the drivers use the 'cur_chan' to detect the end of scan event when
counting scans. The COMEDI_CB_EOS event is automatically added by the core
when the end of scan is detected. The drivers just need to check if the
'cur_chan' is 0 to count the number of scans completed.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers.c

@@ -341,8 +341,15 @@ void comedi_inc_scan_progress(struct comedi_subdevice *s,
 			      unsigned int num_bytes)
 {
 	struct comedi_async *async = s->async;
+	struct comedi_cmd *cmd = &async->cmd;
 	unsigned int scan_length = comedi_bytes_per_scan(s);
 
+	/* track the 'cur_chan' for non-SDF_PACKED subdevices */
+	if (!(s->subdev_flags & SDF_PACKED)) {
+		async->cur_chan += comedi_bytes_to_samples(s, num_bytes);
+		async->cur_chan %= cmd->chanlist_len;
+	}
+
 	async->scan_progress += num_bytes;
 	if (async->scan_progress >= scan_length) {
 		async->scan_progress %= scan_length;

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -1167,8 +1167,6 @@ static void v_APCI3120_InterruptDmaMoveBlock16bit(struct comedi_device *dev,
 
 	devpriv->ui_AiActualScan +=
 		(s->async->cur_chan + num_samples) / cmd->scan_end_arg;
-	s->async->cur_chan += num_samples;
-	s->async->cur_chan %= cmd->scan_end_arg;
 
 	comedi_buf_write_samples(s, dma_buffer, num_samples);
 }

drivers/staging/comedi/drivers/adl_pci9118.c

@@ -483,8 +483,6 @@ static void move_block_from_dma(struct comedi_device *dev,
 	num_samples = defragment_dma_buffer(dev, s, dma_buffer, num_samples);
 	devpriv->ai_act_scan +=
 	    (s->async->cur_chan + num_samples) / cmd->scan_end_arg;
-	s->async->cur_chan += num_samples;
-	s->async->cur_chan %= cmd->scan_end_arg;
 
 	comedi_buf_write_samples(s, dma_buffer, num_samples);
 }
@@ -612,10 +610,8 @@ static void interrupt_pci9118_ai_onesample(struct comedi_device *dev,
 	sampl = inl(dev->iobase + PCI9118_AI_FIFO_REG);
 
 	comedi_buf_write_samples(s, &sampl, 1);
-	s->async->cur_chan++;
-	if (s->async->cur_chan >= cmd->scan_end_arg) {
-							/* one scan done */
-		s->async->cur_chan %= cmd->scan_end_arg;
+
+	if (s->async->cur_chan == 0) {
 		devpriv->ai_act_scan++;
 		if (!devpriv->ai_neverending) {
 			/* all data sampled? */

drivers/staging/comedi/drivers/adv_pci1710.c

@@ -772,11 +772,6 @@ static void pci1710_handle_every_sample(struct comedi_device *dev,
 		val &= s->maxdata;
 		comedi_buf_write_samples(s, &val, 1);
 
-		s->async->cur_chan++;
-		if (s->async->cur_chan >= cmd->chanlist_len)
-			s->async->cur_chan = 0;
-
-
 		if (s->async->cur_chan == 0) {	/*  one scan done */
 			devpriv->ai_act_scan++;
 			if (cmd->stop_src == TRIG_COUNT &&
@@ -800,7 +795,6 @@ static int move_block_from_fifo(struct comedi_device *dev,
 				struct comedi_subdevice *s, int n, int turn)
 {
 	struct pci1710_private *devpriv = dev->private;
-	struct comedi_cmd *cmd = &s->async->cmd;
 	unsigned int val;
 	int ret;
 	int i;
@@ -817,11 +811,8 @@ static int move_block_from_fifo(struct comedi_device *dev,
 		val &= s->maxdata;
 		comedi_buf_write_samples(s, &val, 1);
 
-		s->async->cur_chan++;
-		if (s->async->cur_chan >= cmd->chanlist_len) {
-			s->async->cur_chan = 0;
+		if (s->async->cur_chan == 0)
 			devpriv->ai_act_scan++;
-		}
 	}
 	return 0;
 }

drivers/staging/comedi/drivers/ni_mio_common.c

@@ -1125,14 +1125,10 @@ static void ni_ao_fifo_load(struct comedi_device *dev,
 			    struct comedi_subdevice *s, int n)
 {
 	struct ni_private *devpriv = dev->private;
-	struct comedi_async *async = s->async;
-	struct comedi_cmd *cmd = &async->cmd;
-	int chan;
 	int i;
 	unsigned short d;
 	u32 packed_data;
 
-	chan = async->cur_chan;
 	for (i = 0; i < n; i++) {
 		comedi_buf_read_samples(s, &d, 1);
 
@@ -1141,7 +1137,6 @@ static void ni_ao_fifo_load(struct comedi_device *dev,
 			/* 6711 only has 16 bit wide ao fifo */
 			if (!devpriv->is_6711) {
 				comedi_buf_read_samples(s, &d, 1);
-				chan++;
 				i++;
 				packed_data |= (d << 16) & 0xffff0000;
 			}
@@ -1149,10 +1144,7 @@ static void ni_ao_fifo_load(struct comedi_device *dev,
 		} else {
 			ni_writew(dev, d, DAC_FIFO_Data);
 		}
-		chan++;
-		chan %= cmd->chanlist_len;
 	}
-	async->cur_chan = chan;
 }
 
 /*

drivers/staging/comedi/drivers/pcl812.c

@@ -843,12 +843,8 @@ static bool pcl812_ai_next_chan(struct comedi_device *dev,
 	struct pcl812_private *devpriv = dev->private;
 	struct comedi_cmd *cmd = &s->async->cmd;
 
-	s->async->cur_chan++;
-	if (s->async->cur_chan >= cmd->chanlist_len) {
-		s->async->cur_chan = 0;
+	if (s->async->cur_chan == 0)
 		devpriv->ai_act_scan++;
-		s->async->events |= COMEDI_CB_EOS;
-	}
 
 	if (cmd->stop_src == TRIG_COUNT &&
 	    devpriv->ai_act_scan >= cmd->stop_arg) {
@@ -864,6 +860,7 @@ static void pcl812_handle_eoc(struct comedi_device *dev,
 			      struct comedi_subdevice *s)
 {
 	struct comedi_cmd *cmd = &s->async->cmd;
+	unsigned int chan = s->async->cur_chan;
 	unsigned int next_chan;
 	unsigned short val;
 
@@ -877,10 +874,8 @@ static void pcl812_handle_eoc(struct comedi_device *dev,
 	comedi_buf_write_samples(s, &val, 1);
 
 	/* Set up next channel. Added by abbotti 2010-01-20, but untested. */
-	next_chan = s->async->cur_chan + 1;
-	if (next_chan >= cmd->chanlist_len)
-		next_chan = 0;
-	if (cmd->chanlist[s->async->cur_chan] != cmd->chanlist[next_chan])
+	next_chan = s->async->cur_chan;
+	if (cmd->chanlist[chan] != cmd->chanlist[next_chan])
 		pcl812_ai_set_chan_range(dev, cmd->chanlist[next_chan], 0);
 
 	pcl812_ai_next_chan(dev, s);

drivers/staging/comedi/drivers/pcl816.c

@@ -289,12 +289,8 @@ static bool pcl816_ai_next_chan(struct comedi_device *dev,
 	struct pcl816_private *devpriv = dev->private;
 	struct comedi_cmd *cmd = &s->async->cmd;
 
-	s->async->cur_chan++;
-	if (s->async->cur_chan >= cmd->chanlist_len) {
-		s->async->cur_chan = 0;
+	if (s->async->cur_chan == 0)
 		devpriv->ai_act_scan++;
-		s->async->events |= COMEDI_CB_EOS;
-	}
 
 	if (cmd->stop_src == TRIG_COUNT &&
 	    devpriv->ai_act_scan >= cmd->stop_arg) {

drivers/staging/comedi/drivers/pcl818.c

@@ -525,12 +525,8 @@ static bool pcl818_ai_next_chan(struct comedi_device *dev,
 	if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
 		devpriv->act_chanlist_pos = 0;
 
-	s->async->cur_chan++;
-	if (s->async->cur_chan >= cmd->chanlist_len) {
-		s->async->cur_chan = 0;
+	if (s->async->cur_chan == 0)
 		devpriv->ai_act_scan--;
-		s->async->events |= COMEDI_CB_EOS;
-	}
 
 	if (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan == 0) {
 		/* all data sampled */

drivers/staging/comedi/drivers/rtd520.c

@@ -628,9 +628,6 @@ static int ai_read_n(struct comedi_device *dev, struct comedi_subdevice *s,
 		if (!comedi_buf_write_samples(s, &d, 1))
 			return -1;
 
-		async->cur_chan++;
-		async->cur_chan %= cmd->chanlist_len;
-
 		if (devpriv->ai_count > 0)	/* < 0, means read forever */
 			devpriv->ai_count--;
 	}