diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2015-06-05 18:30:10 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-12 17:06:40 -0700 |
| commit | 5826d99aedda2442f89194cd3b85bc69970c175c (patch) | |
| tree | 904c1effb06917a53c22383de404e02312b74f8c | |
| parent | 3c7cab30f4c4364f72ccd7a034cf81fba7700525 (diff) | |
staging: comedi: das08: rename DAS08_LSB and DAS08_MSB
The `DAS08_LSB` and `DAS08_MSB` macros contain the offsets to the
least-significant and most-significant analog input data registers.
Rename them to `DAS08_AI_LSB_REG` and `DAS08_AI_MSB_REG` respectively
and add comments to document them.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/das08.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index 25213520e965..1d9e6a679327 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -42,8 +42,20 @@ */ -#define DAS08_LSB 0 -#define DAS08_MSB 1 +/* + * Data format of DAS08_AI_LSB_REG and DAS08_AI_MSB_REG depends on + * 'ai_encoding' member of board structure: + * + * das08_encode12 : DATA[11..4] = MSB[7..0], DATA[3..0] = LSB[7..4]. + * das08_pcm_encode12 : DATA[11..8] = MSB[3..0], DATA[7..9] = LSB[7..0]. + * das08_encode16 : SIGN = MSB[7], MAGNITUDE[14..8] = MSB[6..0], + * MAGNITUDE[7..0] = LSB[7..0]. + * SIGN==0 for negative input, SIGN==1 for positive input. + * Note: when read a second time after conversion + * complete, MSB[7] is an "over-range" bit. + */ +#define DAS08_AI_LSB_REG 0x00 /* (R) AI least significant bits */ +#define DAS08_AI_MSB_REG 0x01 /* (R) AI most significant bits */ #define DAS08_TRIG_12BIT 1 #define DAS08_STATUS 2 #define DAS08_EOC (1<<7) @@ -214,8 +226,8 @@ static int das08_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, range = CR_RANGE(insn->chanspec); /* clear crap */ - inb(dev->iobase + DAS08_LSB); - inb(dev->iobase + DAS08_MSB); + inb(dev->iobase + DAS08_AI_LSB_REG); + inb(dev->iobase + DAS08_AI_MSB_REG); /* set multiplexer */ /* lock to prevent race with digital output */ @@ -235,7 +247,7 @@ static int das08_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, for (n = 0; n < insn->n; n++) { /* clear over-range bits for 16-bit boards */ if (thisboard->ai_nbits == 16) - if (inb(dev->iobase + DAS08_MSB) & 0x80) + if (inb(dev->iobase + DAS08_AI_MSB_REG) & 0x80) dev_info(dev->class_dev, "over-range\n"); /* trigger conversion */ @@ -245,8 +257,8 @@ static int das08_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, if (ret) return ret; - msb = inb(dev->iobase + DAS08_MSB); - lsb = inb(dev->iobase + DAS08_LSB); + msb = inb(dev->iobase + DAS08_AI_MSB_REG); + lsb = inb(dev->iobase + DAS08_AI_LSB_REG); if (thisboard->ai_encoding == das08_encode12) { data[n] = (lsb >> 4) | (msb << 4); } else if (thisboard->ai_encoding == das08_pcm_encode12) { |