staging: comedi: addi_apci_1032: conform to new INSN_CONFIG_DIGITAL_TRIG

Conform to the new definition of the `INSN_CONFIG_DIGITAL_TRIG`
configuration instruction.

Return an error if the 'trigger number' in `data[1]` is non-zero or if
the configuration operation in `data[2]` is not supported.  Deal with
the 'left-shift' amount in `data[3]`.

The trigger's input channels can only be configured as a set of rising
and falling edges ('OR' mode) or as a set of high and low levels ('AND'
mode).  Preserve the old input channels to the right of the 'left-shift'
value except when switching modes.

(The 'left-shift' support is a bit of an overkill for this driver since
the trigger only has 16 input channels.)

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 56 insertions, 14 deletions

diff --git a/drivers/staging/comedi/drivers/addi_apci_1032.c b/drivers/staging/comedi/drivers/addi_apci_1032.c
index eb31375e72e..0f47113ee0b 100644
--- a/drivers/staging/comedi/drivers/addi_apci_1032.c
+++ b/drivers/staging/comedi/drivers/addi_apci_1032.c
@@ -86,10 +86,14 @@ static int apci1032_reset(struct comedi_device *dev)
  * The COS interrupt must be configured before it can be enabled.
  *
  *      data[0] : INSN_CONFIG_DIGITAL_TRIG
- *      data[1] : 0 = OR (edge) interrupts
- *                1 = AND (level) interrupts
- *      data[2] : rising-edge/high level channels
- *      data[3] : falling-edge/low level channels
+ *      data[1] : trigger number (= 0)
+ *      data[2] : configuration operation:
+ *                COMEDI_DIGITAL_TRIG_DISABLE = no interrupts
+ *                COMEDI_DIGITAL_TRIG_ENABLE_EDGES = OR (edge) interrupts
+ *                COMEDI_DIGITAL_TRIG_ENABLE_LEVELS = AND (level) interrupts
+ *      data[3] : left-shift for data[4] and data[5]
+ *      data[4] : rising-edge/high level channels
+ *      data[5] : falling-edge/low level channels
  */
 static int apci1032_cos_insn_config(struct comedi_device *dev,
                                     struct comedi_subdevice *s,
@@ -97,21 +101,59 @@ static int apci1032_cos_insn_config(struct comedi_device *dev,
                                     unsigned int *data)
 {
         struct apci1032_private *devpriv = dev->private;
+        unsigned int shift, oldmask;
 
         switch (data[0]) {
         case INSN_CONFIG_DIGITAL_TRIG:
-                devpriv->mode1 = data[2];
-                devpriv->mode2 = data[3];
-
-                if (devpriv->mode1 || devpriv->mode2) {
-                        devpriv->ctrl = APCI1032_CTRL_INT_ENA;
-                        if (data[1] == 1)
-                                devpriv->ctrl = APCI1032_CTRL_INT_AND;
-                        else
-                                devpriv->ctrl = APCI1032_CTRL_INT_OR;
-                } else {
+                if (data[1] != 0)
+                        return -EINVAL;
+                shift = data[3];
+                oldmask = (1U << shift) - 1;
+                switch (data[2]) {
+                case COMEDI_DIGITAL_TRIG_DISABLE:
                         devpriv->ctrl = 0;
+                        devpriv->mode1 = 0;
+                        devpriv->mode2 = 0;
                         apci1032_reset(dev);
+                        break;
+                case COMEDI_DIGITAL_TRIG_ENABLE_EDGES:
+                        if (devpriv->ctrl != (APCI1032_CTRL_INT_ENA |
+                                              APCI1032_CTRL_INT_OR)) {
+                                /* switching to 'OR' mode */
+                                devpriv->ctrl = APCI1032_CTRL_INT_ENA |
+                                                APCI1032_CTRL_INT_OR;
+                                /* wipe old channels */
+                                devpriv->mode1 = 0;
+                                devpriv->mode2 = 0;
+                        } else {
+                                /* preserve unspecified channels */
+                                devpriv->mode1 &= oldmask;
+                                devpriv->mode2 &= oldmask;
+                        }
+                        /* configure specified channels */
+                        devpriv->mode1 |= data[4] << shift;
+                        devpriv->mode2 |= data[5] << shift;
+                        break;
+                case COMEDI_DIGITAL_TRIG_ENABLE_LEVELS:
+                        if (devpriv->ctrl != (APCI1032_CTRL_INT_ENA |
+                                              APCI1032_CTRL_INT_AND)) {
+                                /* switching to 'AND' mode */
+                                devpriv->ctrl = APCI1032_CTRL_INT_ENA |
+                                                APCI1032_CTRL_INT_AND;
+                                /* wipe old channels */
+                                devpriv->mode1 = 0;
+                                devpriv->mode2 = 0;
+                        } else {
+                                /* preserve unspecified channels */
+                                devpriv->mode1 &= oldmask;
+                                devpriv->mode2 &= oldmask;
+                        }
+                        /* configure specified channels */
+                        devpriv->mode1 |= data[4] << shift;
+                        devpriv->mode2 |= data[5] << shift;
+                        break;
+                default:
+                        return -EINVAL;
                 }
                 break;
         default: