diff options
Diffstat (limited to 'drivers/staging/comedi/drivers/skel.c')
| -rw-r--r-- | drivers/staging/comedi/drivers/skel.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/drivers/staging/comedi/drivers/skel.c b/drivers/staging/comedi/drivers/skel.c index 9e964950a560..daee2f42bde0 100644 --- a/drivers/staging/comedi/drivers/skel.c +++ b/drivers/staging/comedi/drivers/skel.c @@ -332,30 +332,44 @@ static int skel_ao_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, return i; } -/* DIO devices are slightly special. Although it is possible to +/* + * DIO devices are slightly special. Although it is possible to * implement the insn_read/insn_write interface, it is much more * useful to applications if you implement the insn_bits interface. - * This allows packed reading/writing of the DIO channels. The - * comedi core can convert between insn_bits and insn_read/write */ + * This allows packed reading/writing of the DIO channels. The + * comedi core can convert between insn_bits and insn_read/write. + */ static int skel_dio_insn_bits(struct comedi_device *dev, struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) + struct comedi_insn *insn, + unsigned int *data) { - /* The insn data is a mask in data[0] and the new data - * in data[1], each channel cooresponding to a bit. */ - if (data[0]) { - s->state &= ~data[0]; - s->state |= data[0] & data[1]; + /* + * The insn data is a mask in data[0] and the new data + * in data[1], each channel cooresponding to a bit. + * + * The core provided comedi_dio_update_state() function can + * be used to handle the internal state update to DIO subdevices + * with <= 32 channels. This function will return '0' if the + * state does not change or the mask of the channels that need + * to be updated. + */ + if (comedi_dio_update_state(s, data)) { /* Write out the new digital output lines */ - /* outw(s->state,dev->iobase + SKEL_DIO); */ + /* outw(s->state, dev->iobase + SKEL_DIO); */ } - /* on return, data[1] contains the value of the digital - * input and output lines. */ - /* data[1]=inw(dev->iobase + SKEL_DIO); */ - /* or we could just return the software copy of the output values if - * it was a purely digital output subdevice */ - /* data[1]=s->state; */ + /* + * On return, data[1] contains the value of the digital + * input and output lines. + */ + /* data[1] = inw(dev->iobase + SKEL_DIO); */ + + /* + * Or we could just return the software copy of the output + * values if it was a purely digital output subdevice. + */ + /* data[1] = s->state; */ return insn->n; } |