From 750bca653d0efae236b07988c013485ccd0a5f22 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Fri, 8 Apr 2016 12:41:47 -0700 Subject: [PATCH] staging: comedi: das1800: add analog output readback Use the core provided readback support to allow reading back the last value written to the analog output channels. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das1800.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c index 52a8c5b8234c..64b5403f9a99 100644 --- a/drivers/staging/comedi/drivers/das1800.c +++ b/drivers/staging/comedi/drivers/das1800.c @@ -91,7 +91,6 @@ Unipolar and bipolar ranges cannot be mixed in the channel/gain list. TODO: Make it automatically allocate irq and dma channels if they are not specified Add support for analog out on 'ao' cards - read insn for analog out */ #include @@ -341,8 +340,6 @@ struct das1800_private { int dma_bits; uint16_t *fifo_buf; /* bounce buffer for analog input FIFO */ unsigned long iobase2; /* secondary io address used for analog out on 'ao' boards */ - unsigned short ao_update_bits; /* remembers the last write to the - * 'update' dac */ bool ai_is_unipolar; }; @@ -1017,7 +1014,6 @@ static int das1800_ao_insn_write(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct das1800_private *devpriv = dev->private; unsigned int chan = CR_CHAN(insn->chanspec); unsigned int update_chan = s->n_chan - 1; unsigned long flags; @@ -1029,9 +1025,9 @@ static int das1800_ao_insn_write(struct comedi_device *dev, for (i = 0; i < insn->n; i++) { unsigned int val = data[i]; + s->readback[chan] = val; + val = comedi_offset_munge(s, val); - if (chan == update_chan) - devpriv->ao_update_bits = val; /* load this channel (and update if it's the last channel) */ outb(DAC(chan), dev->iobase + DAS1800_SELECT); @@ -1039,9 +1035,10 @@ static int das1800_ao_insn_write(struct comedi_device *dev, /* update all channels */ if (chan != update_chan) { + val = comedi_offset_munge(s, s->readback[update_chan]); + outb(DAC(update_chan), dev->iobase + DAS1800_SELECT); - outw(devpriv->ao_update_bits, - dev->iobase + DAS1800_DAC); + outw(val, dev->iobase + DAS1800_DAC); } } spin_unlock_irqrestore(&dev->spinlock, flags); @@ -1318,6 +1315,10 @@ static int das1800_attach(struct comedi_device *dev, s->range_table = &range_bipolar10; s->insn_write = das1800_ao_insn_write; + ret = comedi_alloc_subdev_readback(s); + if (ret) + return ret; + /* initialize all channels to 0V */ for (i = 0; i < s->n_chan; i++) { outb(DAC(i), dev->iobase + DAS1800_SELECT); -- 2.20.1