diff options
| author | H Hartley Sweeten <hsweeten@visionengravers.com> | 2015-10-06 21:11:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-13 08:55:31 +0300 |
| commit | 597063341936a3ccddb30783781d474d7e7d70cd (patch) | |
| tree | 55583885912f92678166d2b12a732f45747a45c1 /drivers | |
| parent | c9ab30239aa33e5d79917303f9c67dff98cc75c3 (diff) | |
| download | linux-597063341936a3ccddb30783781d474d7e7d70cd.tar.xz | |
staging: comedi: mf6x4: A/D converter uses 2's complement coding
According to the user's manual, the A/D converter uses 2's complement
coding. Use the comedi_offset_munge() helper to convert the data to
the offset binary format used by comedi.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
drivers/staging/comedi/drivers/mf6x4.c | 5 ++---
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/comedi/drivers/mf6x4.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/staging/comedi/drivers/mf6x4.c b/drivers/staging/comedi/drivers/mf6x4.c index ff4ba15a23f0..1e4f08058723 100644 --- a/drivers/staging/comedi/drivers/mf6x4.c +++ b/drivers/staging/comedi/drivers/mf6x4.c @@ -38,7 +38,7 @@ #define MF6X4_GPIOC_DACEN BIT(26) /* BAR1 registers */ -#define MF6X4_ADDATA_R 0x00 +#define MF6X4_ADDATA_REG 0x00 #define MF6X4_ADCTRL_REG 0x00 #define MF6X4_ADCTRL_CHAN(x) BIT(chan) #define MF6X4_DIN_R 0x10 @@ -134,9 +134,9 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev, unsigned int *data) { unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int d; int ret; int i; - int d; /* Set the ADC channel number in the scan list */ iowrite16(MF6X4_ADCTRL_CHAN(chan), dev->mmio + MF6X4_ADCTRL_REG); @@ -150,9 +150,10 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev, return ret; /* Read the actual value */ - d = ioread16(dev->mmio + MF6X4_ADDATA_R); + d = ioread16(dev->mmio + MF6X4_ADDATA_REG); d &= s->maxdata; - data[i] = d; + /* munge the 2's complement data to offset binary */ + data[i] = comedi_offset_munge(s, d); } iowrite16(0x0, dev->mmio + MF6X4_ADCTRL_REG); |