From 0546f777627b93022bdb2d8b7fdfb91d2f8f4c74 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 8 Apr 2013 18:20:02 -0700 Subject: [PATCH] staging: comedi: rti800: tidy up analog input 'muxgain' Refactor the code that determines the 'delay' after setting the muxgain register to remove the BUG_ON(). Change the private data 'muxgain_bits' to an unsigned char, the muxgain register is only 8-bits. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/rti800.c | 26 ++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/staging/comedi/drivers/rti800.c b/drivers/staging/comedi/drivers/rti800.c index 30d7245b6bae..e043ed91cdf0 100644 --- a/drivers/staging/comedi/drivers/rti800.c +++ b/drivers/staging/comedi/drivers/rti800.c @@ -156,24 +156,22 @@ struct rti800_private { bool dac_2comp[2]; const struct comedi_lrange *ao_range_type_list[2]; unsigned int ao_readback[2]; - int muxgain_bits; + unsigned char muxgain_bits; }; #define RTI800_TIMEOUT 100 -/* settling delay times in usec for different gains */ -static const int gaindelay[] = { 10, 20, 40, 80 }; - static int rti800_ai_insn_read(struct comedi_device *dev, struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) + struct comedi_insn *insn, + unsigned int *data) { struct rti800_private *devpriv = dev->private; unsigned int chan = CR_CHAN(insn->chanspec); unsigned int gain = CR_RANGE(insn->chanspec); + unsigned char muxgain_bits; int i, t; int status; - unsigned muxgain_bits; inb(dev->iobase + RTI800_ADCHI); outb(0, dev->iobase + RTI800_CLRFLAGS); @@ -182,11 +180,16 @@ static int rti800_ai_insn_read(struct comedi_device *dev, if (muxgain_bits != devpriv->muxgain_bits) { devpriv->muxgain_bits = muxgain_bits; outb(devpriv->muxgain_bits, dev->iobase + RTI800_MUXGAIN); - /* without a delay here, the RTI_OVERRUN bit - * gets set, and you will have an error. */ + /* + * Without a delay here, the RTI_OVERRUN bit + * gets set, and you will have an error. + */ if (insn->n > 0) { - BUG_ON(gain >= ARRAY_SIZE(gaindelay)); - udelay(gaindelay[gain]); + int delay = (gain == 0) ? 10 : + (gain == 1) ? 20 : + (gain == 2) ? 40 : 80; + + udelay(delay); } } @@ -330,7 +333,8 @@ static int rti800_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->adc_coding = it->options[4]; devpriv->dac_2comp[0] = (it->options[6] == 0); devpriv->dac_2comp[1] = (it->options[8] == 0); - devpriv->muxgain_bits = -1; + /* invalid, forces the MUXGAIN register to be set when first used */ + devpriv->muxgain_bits = 0xff; ret = comedi_alloc_subdevices(dev, 4); if (ret) -- 2.30.2