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staging: comedi: dmm32at: introduce dmm32at_ai_set_chanspec()

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Introduce a helper function to set the analog input channel scan and range
control registers. Use the new helper in the analog input (*insn_read) and
(*do_cmd) functions.

The extra sanity checks in the (*do_cmd) are not necessary. The cmd->chanlist
will always be valid and the (*do_cmdtest) validates the channel list in
Step 5.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten
2014-11-11 16:55:27 -07:00
committed by Greg Kroah-Hartman
parent 2dd9681196
commit c5f1b1e552
1 changed files with 20 additions and 33 deletions
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drivers/staging/comedi/drivers/dmm32at.c
+20 -33
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@@ -154,6 +154,24 @@ struct dmm32at_private {
unsigned char dio_config;
};
static void dmm32at_ai_set_chanspec(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned int chanspec, int nchan)
{
unsigned int chan = CR_CHAN(chanspec);
unsigned int range = CR_RANGE(chanspec);
unsigned int last_chan = (chan + nchan - 1) % s->n_chan;
outb(DMM32AT_FIFORESET, dev->iobase + DMM32AT_FIFOCNTRL);
if (nchan > 1)
outb(DMM32AT_SCANENABLE, dev->iobase + DMM32AT_FIFOCNTRL);
outb(chan, dev->iobase + DMM32AT_AILOW);
outb(last_chan, dev->iobase + DMM32AT_AIHIGH);
outb(dmm32at_rangebits[range], dev->iobase + DMM32AT_AICONF);
}
static unsigned int dmm32at_ai_get_sample(struct comedi_device *dev,
struct comedi_subdevice *s)
{
@@ -184,18 +202,10 @@ static int dmm32at_ai_insn_read(struct comedi_device *dev,
struct comedi_insn *insn,
unsigned int *data)
{
unsigned int chan = CR_CHAN(insn->chanspec);
unsigned int range = CR_RANGE(insn->chanspec);
int ret;
int i;
/* zero scan and fifo control and reset fifo */
outb(DMM32AT_FIFORESET, dev->iobase + DMM32AT_FIFOCNTRL);
/* set the channel and range */
outb(chan, dev->iobase + DMM32AT_AILOW);
outb(chan, dev->iobase + DMM32AT_AIHIGH);
outb(dmm32at_rangebits[range], dev->iobase + DMM32AT_AICONF);
dmm32at_ai_set_chanspec(dev, s, insn->chanspec, 1);
/* wait for circuit to settle */
ret = comedi_timeout(dev, s, insn, dmm32at_ai_status, DMM32AT_AIRBACK);
@@ -347,32 +357,9 @@ static void dmm32at_setaitimer(struct comedi_device *dev, unsigned int nansec)
static int dmm32at_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct comedi_cmd *cmd = &s->async->cmd;
int range;
unsigned char chanlo, chanhi;
int ret;
if (!cmd->chanlist)
return -EINVAL;
/* get the channel list and range */
chanlo = CR_CHAN(cmd->chanlist[0]) & (s->n_chan - 1);
chanhi = chanlo + cmd->chanlist_len - 1;
if (chanhi >= s->n_chan)
return -EINVAL;
range = CR_RANGE(cmd->chanlist[0]);
/* reset fifo */
outb(DMM32AT_FIFORESET, dev->iobase + DMM32AT_FIFOCNTRL);
/* set scan enable */
outb(DMM32AT_SCANENABLE, dev->iobase + DMM32AT_FIFOCNTRL);
/* write the ai channel range regs */
outb(chanlo, dev->iobase + DMM32AT_AILOW);
outb(chanhi, dev->iobase + DMM32AT_AIHIGH);
/* set the range bits */
outb(dmm32at_rangebits[range], dev->iobase + DMM32AT_AICONF);
dmm32at_ai_set_chanspec(dev, s, cmd->chanlist[0], cmd->chanlist_len);
/* reset the interrupt just in case */
outb(DMM32AT_INTRESET, dev->iobase + DMM32AT_CNTRL);