Introduce a helper function to stop any ai conversions and reset the
ai control register. This consolidates the common code in me4000_reset()
and me4000_ai_cancel().
Use the new helper in the ai (*insn_read) to ensure that the ai control
register is set to a known state after reading the samples.
The ai control register will now always be '0' after the (*cancel) of
a command or doing an (*insn_read). Knowing this the programming of
the register for single acquisition mode in the (*insn_read) can be
simplified.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/me4000.c | 56 ++++++++++++++-------------------
1 file changed, 23 insertions(+), 33 deletions(-)
diff --git a/drivers/staging/comedi/drivers/me4000.c b/drivers/staging/comedi/drivers/me4000.c
index 3d4a9c8..da0075b 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -393,6 +393,19 @@ static int me4000_xilinx_download(struct comedi_device *dev,
return 0;
}
+static void me4000_ai_reset(struct comedi_device *dev)
+{
+ unsigned int ctrl;
+
+ /* Stop any running conversion */
+ ctrl = inl(dev->iobase + ME4000_AI_CTRL_REG);
+ ctrl |= ME4000_AI_CTRL_STOP | ME4000_AI_CTRL_IMMEDIATE_STOP;
+ outl(ctrl, dev->iobase + ME4000_AI_CTRL_REG);
+
+ /* Clear the control register */
+ outl(0x0, dev->iobase + ME4000_AI_CTRL_REG);
+}
+
static void me4000_reset(struct comedi_device *dev)
{
struct me4000_private *devpriv = dev->private;
@@ -410,12 +423,7 @@ static void me4000_reset(struct comedi_device *dev)
for (chan = 0; chan < 4; chan++)
outl(0x8000, dev->iobase + ME4000_AO_SINGLE_REG(chan));
- /* Set both stop bits in the analog input control register */
- outl(ME4000_AI_CTRL_IMMEDIATE_STOP | ME4000_AI_CTRL_STOP,
- dev->iobase + ME4000_AI_CTRL_REG);
-
- /* Clear the analog input control register */
- outl(0x0, dev->iobase + ME4000_AI_CTRL_REG);
+ me4000_ai_reset(dev);
/* Set both stop bits in the analog output control register */
val = ME4000_AO_CTRL_IMMEDIATE_STOP | ME4000_AO_CTRL_STOP;
@@ -461,8 +469,7 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
unsigned int range = CR_RANGE(insn->chanspec);
unsigned int aref = CR_AREF(insn->chanspec);
unsigned int entry;
- unsigned int tmp;
- int ret;
+ int ret = 0;
int i;
entry = chan | ME4000_AI_LIST_RANGE(range);
@@ -489,20 +496,9 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
entry |= ME4000_AI_LIST_LAST_ENTRY;
- /* Clear channel list, data fifo and both stop bits */
- tmp = inl(dev->iobase + ME4000_AI_CTRL_REG);
- tmp &= ~(ME4000_AI_CTRL_CHANNEL_FIFO | ME4000_AI_CTRL_DATA_FIFO |
- ME4000_AI_CTRL_STOP | ME4000_AI_CTRL_IMMEDIATE_STOP);
- outl(tmp, dev->iobase + ME4000_AI_CTRL_REG);
-
- /* Set the acquisition mode to single */
- tmp &= ~(ME4000_AI_CTRL_MODE_0 | ME4000_AI_CTRL_MODE_1 |
- ME4000_AI_CTRL_MODE_2);
- outl(tmp, dev->iobase + ME4000_AI_CTRL_REG);
-
- /* Enable channel list and data fifo */
- tmp |= ME4000_AI_CTRL_CHANNEL_FIFO | ME4000_AI_CTRL_DATA_FIFO;
- outl(tmp, dev->iobase + ME4000_AI_CTRL_REG);
+ /* Enable channel list and data fifo for single acquisition mode */
+ outl(ME4000_AI_CTRL_CHANNEL_FIFO | ME4000_AI_CTRL_DATA_FIFO,
+ dev->iobase + ME4000_AI_CTRL_REG);
/* Generate channel list entry */
outl(entry, dev->iobase + ME4000_AI_CHANNEL_LIST_REG);
@@ -519,28 +515,22 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
ret = comedi_timeout(dev, s, insn, me4000_ai_eoc, 0);
if (ret)
- return ret;
+ break;
/* read two's complement value and munge to offset binary */
val = inl(dev->iobase + ME4000_AI_DATA_REG);
data[i] = comedi_offset_munge(s, val);
}
- return insn->n;
+ me4000_ai_reset(dev);
+
+ return ret ? ret : insn->n;
}
static int me4000_ai_cancel(struct comedi_device *dev,
struct comedi_subdevice *s)
{
- unsigned int ctrl;
-
- /* Stop any running conversion */
- ctrl = inl(dev->iobase + ME4000_AI_CTRL_REG);
- ctrl |= ME4000_AI_CTRL_STOP | ME4000_AI_CTRL_IMMEDIATE_STOP;
- outl(ctrl, dev->iobase + ME4000_AI_CTRL_REG);
-
- /* Clear the control register */
- outl(0x0, dev->iobase + ME4000_AI_CTRL_REG);
+ me4000_ai_reset(dev);
return 0;
}
--
2.4.3
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