staging: comedi: addi_apci_3xxx: only allocate needed subdevices

The number of subdevices needed by a given board supported by this
driver can cary from 2 (for the apci3500) to a maximum of 5. Currently
this driver always allocates 7 subdevices and sets the subdevice type
to COMEDI_SUBD_UNUSED for the ones that are not needed.

Calculate the actual number of needed subdevices from the boardinfo
and only allocate and setup the ones that are used.

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

diff --git a/drivers/staging/comedi/drivers/addi_apci_3xxx.c b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
index 64471a1..5b37cbf 100644 (file)
--- a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
+++ b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
@@ -790,7 +790,9 @@ static int apci3xxx_auto_attach(struct comedi_device *dev,
        const struct apci3xxx_boardinfo *board = NULL;
        struct apci3xxx_private *devpriv;
        struct comedi_subdevice *s;
-       int ret, n_subdevices;
+       int n_subdevices;
+       int subdev;
+       int ret;
 
        if (context < ARRAY_SIZE(apci3xxx_boardtypes))
                board = &apci3xxx_boardtypes[context];
@@ -818,14 +820,18 @@ static int apci3xxx_auto_attach(struct comedi_device *dev,
                        dev->irq = pcidev->irq;
        }
 
-       n_subdevices = 7;
+       n_subdevices = (board->ai_n_chan ? 0 : 1) + board->has_ao +
+                      board->has_dig_in + board->has_dig_out +
+                      board->has_ttl_io;
        ret = comedi_alloc_subdevices(dev, n_subdevices);
        if (ret)
                return ret;
 
+       subdev = 0;
+
        /* Analog Input subdevice */
-       s = &dev->subdevices[0];
        if (board->ai_n_chan) {
+               s = &dev->subdevices[subdev];
                s->type         = COMEDI_SUBD_AI;
                s->subdev_flags = SDF_READABLE | board->ai_subdev_flags;
                s->n_chan       = board->ai_n_chan;
@@ -840,56 +846,52 @@ static int apci3xxx_auto_attach(struct comedi_device *dev,
                        s->do_cmd       = apci3xxx_ai_cmd;
                        s->cancel       = apci3xxx_ai_cancel;
                }
-       } else {
-               s->type = COMEDI_SUBD_UNUSED;
+
+               subdev++;
        }
 
        /* Analog Output subdevice */
-       s = &dev->subdevices[1];
        if (board->has_ao) {
+               s = &dev->subdevices[subdev];
                s->type         = COMEDI_SUBD_AO;
                s->subdev_flags = SDF_WRITEABLE | SDF_GROUND | SDF_COMMON;
                s->n_chan       = 4;
                s->maxdata      = 0x0fff;
                s->range_table  = &apci3xxx_ao_range;
                s->insn_write   = apci3xxx_ao_insn_write;
-       } else {
-               s->type         = COMEDI_SUBD_UNUSED;
+
+               subdev++;
        }
 
        /* Digital Input subdevice */
-       s = &dev->subdevices[2];
        if (board->has_dig_in) {
+               s = &dev->subdevices[subdev];
                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    = apci3xxx_di_insn_bits;
-       } else {
-               s->type         = COMEDI_SUBD_UNUSED;
+
+               subdev++;
        }
 
        /* Digital Output subdevice */
-       s = &dev->subdevices[3];
        if (board->has_dig_out) {
+               s = &dev->subdevices[subdev];
                s->type         = COMEDI_SUBD_DO;
                s->subdev_flags = SDF_WRITEABLE;
                s->n_chan       = 4;
                s->maxdata      = 1;
                s->range_table  = &range_digital;
                s->insn_bits    = apci3xxx_do_insn_bits;
-       } else {
-               s->type         = COMEDI_SUBD_UNUSED;
-       }
 
-       /*  Allocate and Initialise Timer Subdevice Structures */
-       s = &dev->subdevices[4];
-       s->type = COMEDI_SUBD_UNUSED;
+               subdev++;
+       }
 
        /* TTL Digital I/O subdevice */
-       s = &dev->subdevices[5];
        if (board->has_ttl_io) {
+               s = &dev->subdevices[subdev];
                s->type         = COMEDI_SUBD_DIO;
                s->subdev_flags = SDF_READABLE | SDF_WRITEABLE;
                s->n_chan       = 24;
@@ -898,13 +900,9 @@ static int apci3xxx_auto_attach(struct comedi_device *dev,
                s->range_table  = &range_digital;
                s->insn_config  = apci3xxx_dio_insn_config;
                s->insn_bits    = apci3xxx_dio_insn_bits;
-       } else {
-               s->type = COMEDI_SUBD_UNUSED;
-       }
 
-       /* EEPROM */
-       s = &dev->subdevices[6];
-       s->type = COMEDI_SUBD_UNUSED;
+               subdev++;
+       }
 
        apci3xxx_reset(dev);
        return 0;