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Commit c5f1b1e5 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: dmm32at: introduce dmm32at_ai_set_chanspec() 



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: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2dd96811

drivers/staging/comedi/drivers/dmm32at.c

+20 −33
Original line number Diff line number Diff line
@@ -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);