From d615416de6157812e6d7b732991ece884fc6c59e Mon Sep 17 00:00:00 2001
From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Tue, 20 Jan 2015 12:06:03 -0700
Subject: [PATCH] staging: comedi: pcl818: introduce pcl818_ai_write_sample()
This driver can acquire analog input samples during the async command with
DMA, by using the FIFO, or sample-by-sample using the End-Of-Conversion
interrupt. All three methods do the following sequence:
1) check for channel dropout
2) add the sample to the async buffer
3) advance the channel dropout detection and detect the end of the command
Merge this sequence into a new helper function.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcl818.c | 41 ++++++-------------------
1 file changed, 9 insertions(+), 32 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl818.c b/drivers/staging/comedi/drivers/pcl818.c
index 6e5d8bfb1c6d0..a10ce41067ee7 100644
--- a/drivers/staging/comedi/drivers/pcl818.c
+++ b/drivers/staging/comedi/drivers/pcl818.c
@@ -454,11 +454,12 @@ static int pcl818_ai_eoc(struct comedi_device *dev,
return -EBUSY;
}
-static bool pcl818_ai_dropout(struct comedi_device *dev,
- struct comedi_subdevice *s,
- unsigned int chan)
+static bool pcl818_ai_write_sample(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ unsigned int chan, unsigned int val)
{
struct pcl818_private *devpriv = dev->private;
+ struct comedi_cmd *cmd = &s->async->cmd;
unsigned int expected_chan;
expected_chan = devpriv->act_chanlist[devpriv->act_chanlist_pos];
@@ -469,16 +470,10 @@ static bool pcl818_ai_dropout(struct comedi_device *dev,
(devpriv->usefifo) ? "FIFO" : "IRQ",
chan, expected_chan);
s->async->events |= COMEDI_CB_ERROR;
- return true;
+ return false;
}
- return false;
-}
-static bool pcl818_ai_next_chan(struct comedi_device *dev,
- struct comedi_subdevice *s)
-{
- struct pcl818_private *devpriv = dev->private;
- struct comedi_cmd *cmd = &s->async->cmd;
+ comedi_buf_write_samples(s, &val, 1);
devpriv->act_chanlist_pos++;
if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
@@ -506,13 +501,7 @@ static void pcl818_handle_eoc(struct comedi_device *dev,
}
val = pcl818_ai_get_sample(dev, s, &chan);
-
- if (pcl818_ai_dropout(dev, s, chan))
- return;
-
- comedi_buf_write_samples(s, &val, 1);
-
- pcl818_ai_next_chan(dev, s);
+ pcl818_ai_write_sample(dev, s, chan, val);
}
static void pcl818_handle_dma(struct comedi_device *dev,
@@ -535,13 +524,7 @@ static void pcl818_handle_dma(struct comedi_device *dev,
val = ptr[i];
chan = val & 0xf;
val = (val >> 4) & s->maxdata;
-
- if (pcl818_ai_dropout(dev, s, chan))
- break;
-
- comedi_buf_write_samples(s, &val, 1);
-
- if (!pcl818_ai_next_chan(dev, s))
+ if (!pcl818_ai_write_sample(dev, s, chan, val))
break;
}
}
@@ -576,13 +559,7 @@ static void pcl818_handle_fifo(struct comedi_device *dev,
for (i = 0; i < len; i++) {
val = pcl818_ai_get_fifo_sample(dev, s, &chan);
-
- if (pcl818_ai_dropout(dev, s, chan))
- break;
-
- comedi_buf_write_samples(s, &val, 1);
-
- if (!pcl818_ai_next_chan(dev, s))
+ if (!pcl818_ai_write_sample(dev, s, chan, val))
break;
}
}
--
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