From 8432eb35a924440e21bccd965009b101a37a3aad Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 31 Aug 2012 20:41:43 +0100 Subject: [PATCH] staging: comedi: das08: Initialize AO channels Initialize the AO subdevice channels to mid-range data value so they are in a known state. This allows us to support reading back the current value in a later patch. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das08.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index 13e6ac75b0e..0457b9b7ef2 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -391,6 +391,17 @@ static void das08_ao_set_data(struct comedi_device *dev, } } +static void das08_ao_initialize(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + int n; + unsigned int data; + + data = s->maxdata / 2; /* should be about 0 volts */ + for (n = 0; n < s->n_chan; n++) + das08_ao_set_data(dev, n, data); +} + static int das08_ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_insn *insn, unsigned int *data) @@ -665,6 +676,7 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase) s->maxdata = (1 << thisboard->ao_nbits) - 1; s->range_table = &range_bipolar5; s->insn_write = das08_ao_winsn; + das08_ao_initialize(dev, s); } else { s->type = COMEDI_SUBD_UNUSED; } -- 2.41.0