staging: comedi: adl_pci6208: split the digital i/o subdevice

The PCI-6208/6216 cards have 4 digital inputs and 4 digital outputs.
These are currently being handled by an 8 channel COMEDI_SUBD_DIO
subdevice in this driver. This causes the 4 digital outputs to
appear as channels 0 thru 3 and the 4 digital inputs to appear as
channels 4 thru 7. Userspace can only work out part thisby doing the
COMEDI_INSNLIST ioctl with the INSN_CONFIG_DIO_QUERY instruction
for each channel to determine the io direction.

Make things a bit cleaner for userspace by creating two subdevices
instead. One for the 4 digital inputs and one for the 4 digital
outputs. For both subdevices the channel number indicates the
actual digital input/output signal.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/adl_pci6208.c b/drivers/staging/comedi/drivers/adl_pci6208.c
index 43e23e179959e0138ef41e6ae633881ff0fa6ffd..74695bbd5f3feb4c2ff6ecf5e58e0b9cdec4f1e3 100644 (file)
--- a/drivers/staging/comedi/drivers/adl_pci6208.c
+++ b/drivers/staging/comedi/drivers/adl_pci6208.c
@@ -125,46 +125,41 @@ static int pci6208_ao_rinsn(struct comedi_device *dev,
        return insn->n;
 }
 
-static int pci6208_dio_insn_bits(struct comedi_device *dev,
-                                struct comedi_subdevice *s,
-                                struct comedi_insn *insn,
-                                unsigned int *data)
+static int pci6208_di_insn_bits(struct comedi_device *dev,
+                               struct comedi_subdevice *s,
+                               struct comedi_insn *insn,
+                               unsigned int *data)
 {
-       unsigned int mask = data[0] & PCI6208_DIO_DO_MASK;
+       unsigned int val;
+
+       val = inw(dev->iobase + PCI6208_DIO);
+       val = (val & PCI6208_DIO_DI_MASK) >> PCI6208_DIO_DI_SHIFT;
+
+       data[1] = val;
+
+       return insn->n;
+}
+
+static int pci6208_do_insn_bits(struct comedi_device *dev,
+                               struct comedi_subdevice *s,
+                               struct comedi_insn *insn,
+                               unsigned int *data)
+{
+       unsigned int mask = data[0];
        unsigned int bits = data[1];
 
        if (mask) {
                s->state &= ~mask;
-               s->state |= bits & mask;
+               s->state |= (bits & mask);
 
                outw(s->state, dev->iobase + PCI6208_DIO);
        }
 
-       s->state = inw(dev->iobase + PCI6208_DIO);
        data[1] = s->state;
 
        return insn->n;
 }
 
-static int pci6208_dio_insn_config(struct comedi_device *dev,
-                                  struct comedi_subdevice *s,
-                                  struct comedi_insn *insn,
-                                  unsigned int *data)
-{
-       int chan = CR_CHAN(insn->chanspec);
-       unsigned int mask = 1 << chan;
-
-       switch (data[0]) {
-       case INSN_CONFIG_DIO_QUERY:
-               data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       return insn->n;
-}
-
 static const void *pci6208_find_boardinfo(struct comedi_device *dev,
                                          struct pci_dev *pcidev)
 {
@@ -185,6 +180,7 @@ static int pci6208_attach_pci(struct comedi_device *dev,
        const struct pci6208_board *boardinfo;
        struct pci6208_private *devpriv;
        struct comedi_subdevice *s;
+       unsigned int val;
        int ret;
 
        comedi_set_hw_dev(dev, &pcidev->dev);
@@ -208,7 +204,7 @@ static int pci6208_attach_pci(struct comedi_device *dev,
        }
        dev->iobase = pci_resource_start(pcidev, 2);
 
-       ret = comedi_alloc_subdevices(dev, 2);
+       ret = comedi_alloc_subdevices(dev, 3);
        if (ret)
                return ret;
 
@@ -223,17 +219,31 @@ static int pci6208_attach_pci(struct comedi_device *dev,
        s->insn_read    = pci6208_ao_rinsn;
 
        s = dev->subdevices + 1;
-       /* digital i/o subdevice */
-       s->type         = COMEDI_SUBD_DIO;
-       s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
-       s->n_chan       = 8;
+       /* digital input subdevice */
+       s->type         = COMEDI_SUBD_DI;
+       s->subdev_flags = SDF_READABLE;
+       s->n_chan       = 4;
        s->maxdata      = 1;
        s->range_table  = &range_digital;
-       s->insn_bits    = pci6208_dio_insn_bits;
-       s->insn_config  = pci6208_dio_insn_config;
+       s->insn_bits    = pci6208_di_insn_bits;
 
+       s = dev->subdevices + 2;
+       /* digital output subdevice */
+       s->type         = COMEDI_SUBD_DO;
+       s->subdev_flags = SDF_WRITABLE;
+       s->n_chan       = 4;
+       s->maxdata      = 1;
+       s->range_table  = &range_digital;
+       s->insn_bits    = pci6208_do_insn_bits;
+
+       /*
+        * Get the read back signals from the digital outputs
+        * and save it as the initial state for the subdevice.
+        */
+       val = inw(dev->iobase + PCI6208_DIO);
+       val = (val & PCI6208_DIO_DO_MASK) >> PCI6208_DIO_DO_SHIFT;
+       s->state        = val;
        s->io_bits      = 0x0f;
-       s->state        = inw(dev->iobase + PCI6208_DIO);
 
        dev_info(dev->class_dev, "%s: %s, I/O base=0x%04lx\n",
                dev->driver->driver_name, dev->board_name, dev->iobase);