Now that the scanning and interrupt support have been removed from this
function it can be refactored to work correctly.
The comedi core expects (*insn_read) functions to read insn->n values
from the hardware and return the number of samples read. This function
currently just reads one sample but it returns insn->n.
Fix this function to work like the core expects.
Use comedi_timeout() to prevent a possible deadlock in the loop that
waits for the end-of-conversion.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
.../comedi/drivers/addi-data/hwdrv_apci3120.c | 90 ++++++++++------------
1 file changed, 40 insertions(+), 50 deletions(-)
diff --git a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
index 51cdecb..5fb8848 100644
--- a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
+++ b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
@@ -139,6 +139,19 @@ static int apci3120_setup_chan_list(struct comedi_device *dev,
return 1; /* we can serve this with scan logic */
}
+static int apci3120_ai_eoc(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned long context)
+{
+ unsigned int status;
+
+ status = inw(dev->iobase + APCI3120_RD_STATUS);
+ if ((status & APCI3120_EOC) == 0)
+ return 0;
+ return -EBUSY;
+}
+
static int apci3120_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
@@ -146,67 +159,44 @@ static int apci3120_ai_insn_read(struct comedi_device *dev,
{
struct apci3120_private *devpriv = dev->private;
unsigned int divisor;
- unsigned int ns;
- unsigned short us_TmpValue;
-
- /* fix conversion time to 10 us */
- ns = 10000;
-
- /* Clear software registers */
- devpriv->timer_mode = 0;
- devpriv->mode = 0;
-
- if (insn->unused[0] == 222) { /* second insn read */
- } else {
- devpriv->tsk_Current = current; /* Save the current process task structure */
-
- divisor = apci3120_ns_to_timer(dev, 0, ns, CMDF_ROUND_NEAREST);
-
- us_TmpValue = (unsigned short) devpriv->b_InterruptMode;
-
- switch (us_TmpValue) {
-
- case APCI3120_EOC_MODE:
- apci3120_ai_reset_fifo(dev);
-
- /* Initialize the sequence array */
- if (!apci3120_setup_chan_list(dev, s, 1,
- &insn->chanspec))
- return -EINVAL;
-
- /* Initialize Timer 0 mode 4 */
- apci3120_timer_set_mode(dev, 0, APCI3120_TIMER_MODE4);
+ int ret;
+ int i;
- outb(devpriv->mode, dev->iobase + APCI3120_MODE_REG);
+ /* set mode for A/D conversions by software trigger with timer 0 */
+ devpriv->mode = APCI3120_MODE_TIMER2_CLK_OSC |
+ APCI3120_MODE_TIMER2_AS_TIMER;
+ outb(devpriv->mode, dev->iobase + APCI3120_MODE_REG);
- apci3120_timer_enable(dev, 0, true);
+ /* load chanlist for single channel scan */
+ if (!apci3120_setup_chan_list(dev, s, 1, &insn->chanspec))
+ return -EINVAL;
- /* Set the conversion time */
- apci3120_timer_write(dev, 0, divisor);
+ /*
+ * Timer 0 is used in MODE4 (software triggered strobe) to set the
+ * conversion time for each acquisition. Each conversion is triggered
+ * when the divisor is written to the timer, The conversion is done
+ * when the EOC bit in the status register is '0'.
+ */
+ apci3120_timer_set_mode(dev, 0, APCI3120_TIMER_MODE4);
+ apci3120_timer_enable(dev, 0, true);
- us_TmpValue =
- (unsigned short) inw(dev->iobase + APCI3120_RD_STATUS);
+ /* fixed conversion time of 10 us */
+ divisor = apci3120_ns_to_timer(dev, 0, 10000, CMDF_ROUND_NEAREST);
- do {
- /* Waiting for the end of conversion */
- us_TmpValue = inw(dev->iobase +
- APCI3120_RD_STATUS);
- } while ((us_TmpValue & APCI3120_EOC) == APCI3120_EOC);
+ apci3120_ai_reset_fifo(dev);
- /* Read the result in FIFO and put it in insn data pointer */
- us_TmpValue = inw(dev->iobase + 0);
- *data = us_TmpValue;
+ for (i = 0; i < insn->n; i++) {
+ /* trigger conversion */
+ apci3120_timer_write(dev, 0, divisor);
- apci3120_ai_reset_fifo(dev);
- break;
- default:
- dev_err(dev->class_dev, "inputs wrong\n");
+ ret = comedi_timeout(dev, s, insn, apci3120_ai_eoc, 0);
+ if (ret)
+ return ret;
- }
+ data[i] = inw(dev->iobase + 0);
}
return insn->n;
-
}
static int apci3120_reset(struct comedi_device *dev)
--
2.0.3
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