diff options
author | Ian Abbott <abbotti@mev.co.uk> | 2012-08-31 19:41:44 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-04 19:00:42 (GMT) |
commit | f0ba1d6e19c5e7f91005eaa4d9c14851e217feea (patch) | |
tree | c255f7a1c665f3d2af1d8dd15dc858e18c800c7f /drivers/staging | |
parent | 8432eb35a924440e21bccd965009b101a37a3aad (diff) | |
download | linux-fsl-qoriq-f0ba1d6e19c5e7f91005eaa4d9c14851e217feea.tar.xz |
staging: comedi: das08: Support read-back of AO subdevice
Stash the last value written to each AO channel in private data and
support the INSN_READ instruction to read it back. Don't bother setting
the SDF_READABLE subdevice flag though as the hardware isn't really
readable - we're just faking it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
-rw-r--r-- | drivers/staging/comedi/drivers/das08.c | 20 | ||||
-rw-r--r-- | drivers/staging/comedi/drivers/das08.h | 1 |
2 files changed, 20 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index 0457b9b..623e77e 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -373,6 +373,7 @@ static void das08_ao_set_data(struct comedi_device *dev, unsigned int chan, unsigned int data) { const struct das08_board_struct *thisboard = comedi_board(dev); + struct das08_private_struct *devpriv = dev->private; unsigned char lsb; unsigned char msb; @@ -389,6 +390,7 @@ static void das08_ao_set_data(struct comedi_device *dev, /* load DACs */ inb(dev->iobase + DAS08AO_AO_UPDATE); } + devpriv->ao_readback[chan] = data; } static void das08_ao_initialize(struct comedi_device *dev, @@ -417,6 +419,22 @@ static int das08_ao_winsn(struct comedi_device *dev, return n; } +static int das08_ao_rinsn(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, unsigned int *data) +{ + struct das08_private_struct *devpriv = dev->private; + unsigned int n; + unsigned int chan; + + chan = CR_CHAN(insn->chanspec); + + for (n = 0; n < insn->n; n++) + data[n] = devpriv->ao_readback[chan]; + + return n; +} + static void i8254_initialize(struct comedi_device *dev) { const struct das08_board_struct *thisboard = comedi_board(dev); @@ -670,12 +688,12 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase) /* ao */ if (thisboard->ao_nbits) { s->type = COMEDI_SUBD_AO; -/* XXX lacks read-back insn */ s->subdev_flags = SDF_WRITABLE; s->n_chan = 2; s->maxdata = (1 << thisboard->ao_nbits) - 1; s->range_table = &range_bipolar5; s->insn_write = das08_ao_winsn; + s->insn_read = das08_ao_rinsn; das08_ao_initialize(dev, s); } else { s->type = COMEDI_SUBD_UNUSED; diff --git a/drivers/staging/comedi/drivers/das08.h b/drivers/staging/comedi/drivers/das08.h index 5a33993..4231be5 100644 --- a/drivers/staging/comedi/drivers/das08.h +++ b/drivers/staging/comedi/drivers/das08.h @@ -52,6 +52,7 @@ struct das08_private_struct { unsigned int do_bits; /* bits for do register on boards with register dedicated to digital out only */ const unsigned int *pg_gainlist; struct pci_dev *pdev; /* struct for pci-das08 */ + unsigned int ao_readback[2]; /* assume 2 AO channels */ }; int das08_common_attach(struct comedi_device *dev, unsigned long iobase); |