Avoid using software conversion trigger as it doesn't work very well for

differential mode on some versions of PCI230/260.  Use Z2 timer 2 output
instead and toggle the output in software to trigger a conversion.  Note
that the ADC busy bit only works for software triggers in non-FIFO mode,
so for AI INSN_READ, use the FIFO and the FIFO status bits to check when
the conversion is complete.

diff --git a/comedi/drivers/amplc_pci230.c b/comedi/drivers/amplc_pci230.c
index ff997dec51e4cc3c41b7eae7d71428f1e311c6e3..119f8a22c839ea0fd74c2a3b1c1474ceed8bd159 100644 (file)
--- a/comedi/drivers/amplc_pci230.c
+++ b/comedi/drivers/amplc_pci230.c
@@ -814,9 +814,6 @@ static int pci230_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
        chan = CR_CHAN(insn->chanspec);
        range = CR_RANGE(insn->chanspec);
        aref = CR_AREF(insn->chanspec);
-
-       adccon = PCI230_ADC_TRIG_SW;
-       devpriv->ai_bipolar = pci230_ai_bipolar[range];
        if (aref == AREF_DIFF) {
                /* Differential. */
                if (chan >= s->n_chan / 2) {
@@ -825,6 +822,19 @@ static int pci230_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
                                "0 to %u\n", dev->minor, (s->n_chan / 2) - 1);
                        return -EINVAL;
                }
+       }
+
+       /* Use Z2-CT2 as a conversion trigger instead of the built-in
+        * software trigger, as otherwise triggering of differential channels
+        * doesn't work properly for some versions of PCI230/260.  Also set
+        * FIFO mode because the ADC busy bit only works for software triggers.
+        */
+       adccon = PCI230_ADC_TRIG_Z2CT2 | PCI230_ADC_FIFO_EN;
+       /* Set Z2-CT2 output low to avoid any false triggers. */
+       i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, 2, I8254_MODE0);
+       devpriv->ai_bipolar = pci230_ai_bipolar[range];
+       if (aref == AREF_DIFF) {
+               /* Differential. */
                gainshift = chan * 2;
                if (devpriv->hwver == 0) {
                        /* Original PCI230/260 expects both inputs of the
@@ -857,22 +867,26 @@ static int pci230_ai_rinsn(comedi_device * dev, comedi_subdevice * s,
        /* Set gain for channel. */
        outw(devpriv->adcg, dev->iobase + PCI230_ADCG);
 
-       /* Specify uni/bip, se/diff, s/w conversion, and reset FIFO (even
-        * though we're not using it - MEV says so). */
+       /* Specify uni/bip, se/diff, conversion source, and reset FIFO. */
        devpriv->adccon = adccon;
        outw(adccon | PCI230_ADC_FIFO_RESET, dev->iobase + PCI230_ADCCON);
 
        /* Convert n samples */
        for (n = 0; n < insn->n; n++) {
-               /* trigger conversion */
-               outw(PCI230_ADC_CONV, dev->iobase + PCI230_ADCSWTRIG);
+               /* Trigger conversion by toggling Z2-CT2 output (finish with
+                * output high). */
+               i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, 2,
+                       I8254_MODE0);
+               i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, 2,
+                       I8254_MODE1);
 
 #define TIMEOUT 100
                /* wait for conversion to end */
                for (i = 0; i < TIMEOUT; i++) {
                        status = inw(dev->iobase + PCI230_ADCCON);
-                       if (!(status & PCI230_ADC_BUSY))
+                       if (!(status & PCI230_ADC_FIFO_EMPTY))
                                break;
+                       comedi_udelay(1);
                }
                if (i == TIMEOUT) {
                        /* rt_printk() should be used instead of printk()
@@ -1703,12 +1717,17 @@ static int pci230_ai_inttrig_convert(comedi_device * dev, comedi_subdevice * s,
 
                comedi_spin_unlock_irqrestore(&devpriv->ai_inttrig_spinlock,
                        irqflags);
-               /* Trigger conversion. */
-               outw(PCI230_ADC_CONV, dev->iobase + PCI230_ADCSWTRIG);
+               /* Trigger conversion by toggling Z2-CT2 output.  Finish
+                * with output high. */
+               i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, 2,
+                       I8254_MODE0);
+               i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, 2,
+                       I8254_MODE1);
                /* Delay.  Should driver be responsible for this?  An
                 * alternative would be to wait until conversion is complete,
                 * but we can't tell when it's complete because the ADC busy
-                * bit has a different meaning when FIFO enabled. */
+                * bit has a different meaning when FIFO enabled (and when
+                * FIFO not enabled, it only works for software triggers). */
                if (((devpriv->adccon & PCI230_ADC_IM_MASK)
                                == PCI230_ADC_IM_DIF)
                        && (devpriv->hwver == 0)) {
@@ -1804,7 +1823,9 @@ static void pci230_ai_start(comedi_device * dev, comedi_subdevice * s)
                        }
                        break;
                case TRIG_INT:
-                       conv = PCI230_ADC_TRIG_SW;
+                       /* Use CT2 output for software trigger due to problems
+                        * in differential mode on PCI230/260. */
+                       conv = PCI230_ADC_TRIG_Z2CT2;
                        comedi_spin_lock_irqsave(&devpriv->ai_inttrig_spinlock,
                                irqflags);
                        async->inttrig = pci230_ai_inttrig_convert;
@@ -1890,9 +1911,6 @@ static void pci230_ai_start(comedi_device * dev, comedi_subdevice * s)
                                        break;
                                }
                        }
-               } else {
-                       /* No longer need Z2-CT2. */
-                       put_one_resource(dev, RES_Z2CT2, OWNER_AICMD);
                }
        }
 }
@@ -2187,8 +2205,9 @@ static void pci230_ct_setup_ns_mode(comedi_device * dev, unsigned int ct,
 
 static void pci230_cancel_ct(comedi_device * dev, unsigned int ct)
 {
-       i8254_load(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, ct, 0, 0);
-       /* Counter ct, divisor 0, 8254 mode 0. */
+       i8254_set_mode(devpriv->iobase1 + PCI230_Z2_CT_BASE, 0, ct,
+               I8254_MODE1);
+       /* Counter ct, 8254 mode 1, initial count not written. */
 }
 
 /* Interrupt handler */