Staging: comedi: s526: Fix number of channels on DIO subdevice

Correct operation of INSN_CONFIG_DIO_INPUT and INSN_CONFIG_DIO_OUTPUT
and support INSN_CONFIG_DIO_QUERY.  Thanks to Alessio Margan for some
testing.

Signed-off-by: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 20 insertions, 15 deletions

diff --git a/drivers/staging/comedi/drivers/s526.c b/drivers/staging/comedi/drivers/s526.c
index b89e1ec267c5..736441f3c815 100644
--- a/drivers/staging/comedi/drivers/s526.c
+++ b/drivers/staging/comedi/drivers/s526.c
@@ -375,7 +375,7 @@ static int s526_attach(struct comedi_device *dev, struct comedi_devconfig *it)
         if (thisboard->have_dio) {
                 s->type = COMEDI_SUBD_DIO;
                 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
-                s->n_chan = 2;
+                s->n_chan = 8;
                 s->maxdata = 1;
                 s->range_table = &range_digital;
                 s->insn_bits = s526_dio_insn_bits;
@@ -949,7 +949,7 @@ static int s526_dio_insn_bits(struct comedi_device *dev,
         data[1] = inw(ADDR_REG(REG_DIO)) & 0xFF;        /*  low 8 bits are the data */
         /* or we could just return the software copy of the output values if
          * it was a purely digital output subdevice */
-        /* data[1]=s->state; */
+        /* data[1]=s->state & 0xFF; */
 
         return 2;
 }
@@ -959,28 +959,33 @@ static int s526_dio_insn_config(struct comedi_device *dev,
                                 struct comedi_insn *insn, unsigned int *data)
 {
         int chan = CR_CHAN(insn->chanspec);
-        short value;
+        int group, mask;
 
         printk("S526 DIO insn_config\n");
 
-        if (insn->n != 1)
-                return -EINVAL;
-
-        value = inw(ADDR_REG(REG_DIO));
-
         /* The input or output configuration of each digital line is
          * configured by a special insn_config instruction.  chanspec
          * contains the channel to be changed, and data[0] contains the
          * value COMEDI_INPUT or COMEDI_OUTPUT. */
 
-        if (data[0] == COMEDI_OUTPUT) {
-                value |= 1 << (chan + 10);      /*  bit 10/11 set the group 1/2's mode */
-                s->io_bits |= (0xF << chan);
-        } else {
-                value &= ~(1 << (chan + 10));   /*  1 is output, 0 is input. */
-                s->io_bits &= ~(0xF << chan);
+        group = chan >> 2;
+        mask = 0xF << (group << 2);
+        switch (data[0]) {
+        case INSN_CONFIG_DIO_OUTPUT:
+                s->state |= 1 << (group + 10);  // bit 10/11 set the group 1/2's mode
+                s->io_bits |= mask;
+                break;
+        case INSN_CONFIG_DIO_INPUT:
+                s->state &= ~(1 << (group + 10));// 1 is output, 0 is input.
+                s->io_bits &= ~mask;
+                break;
+        case INSN_CONFIG_DIO_QUERY:
+                data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
+                return insn->n;
+        default:
+                return -EINVAL;
         }
-        outw(value, ADDR_REG(REG_DIO));
+        outw(s->state, ADDR_REG(REG_DIO));
 
         return 1;
 }