Use the comedi_subdevice 'readback' member and the core provided (*insn_read) function to provide radback of the analog output channels.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com> Cc: Ian Abbott <abbo...@mev.co.uk> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c | 2 ++ drivers/staging/comedi/drivers/addi_apci_3120.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c index 47b1741..c093cd4 100644 --- a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c +++ b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c @@ -1924,6 +1924,8 @@ static int apci3120_ao_insn_write(struct comedi_device *dev, outw(APCI3120_AO_MUX(chan) | APCI3120_AO_DATA(val), dev->iobase + APCI3120_AO_REG(chan)); + + s->readback[chan] = val; } return insn->n; diff --git a/drivers/staging/comedi/drivers/addi_apci_3120.c b/drivers/staging/comedi/drivers/addi_apci_3120.c index abc85bf..5db52cd 100644 --- a/drivers/staging/comedi/drivers/addi_apci_3120.c +++ b/drivers/staging/comedi/drivers/addi_apci_3120.c @@ -195,6 +195,11 @@ static int apci3120_auto_attach(struct comedi_device *dev, s->maxdata = 0x3fff; s->range_table = &range_bipolar10; s->insn_write = apci3120_ao_insn_write; + s->insn_read = comedi_readback_insn_read; + + ret = comedi_alloc_subdev_readback(s); + if (ret) + return ret; } else { s->type = COMEDI_SUBD_UNUSED; } -- 2.0.3 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel