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staging: comedi: adl_pci9118: clarify the digital I/O register

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The same register is used for both the digital inputs and outputs.
Reading the register returns the state of the 4 digtial input channels
and the 4 digital output channels. Writing to the register updates the
digital outputs.

Add some comments to clarify this and use a single define for the register.

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
2014-09-04 12:14:18 -07:00
committed by Greg Kroah-Hartman
parent 862be05ecf
commit c7f499bd03
1 changed files with 17 additions and 6 deletions
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23
drivers/staging/comedi/drivers/adl_pci9118.c
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@@ -129,9 +129,8 @@
#define PCI9118_AI_CTRL_TMRTR (1 << 2) /* 1=8254 is trigger source */
#define PCI9118_AI_CTRL_INT (1 << 1) /* 1=enable interrupt */
#define PCI9118_AI_CTRL_DMA (1 << 0) /* 1=enable DMA */
#define PCI9118_DIO_REG 0x1c
#define PCI9118_DI 0x1c /* R: digi input register */
#define PCI9118_DO 0x1c /* W: digi output register */
#define PCI9118_SOFTTRG 0x20 /* W: soft trigger for A/D */
#define PCI9118_GAIN 0x24 /* W: A/D gain/channel register */
#define PCI9118_BURST 0x28 /* W: A/D burst number register */
@@ -565,9 +564,15 @@ static int pci9118_insn_read_ao(struct comedi_device *dev,
static int pci9118_insn_bits_di(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
struct comedi_insn *insn,
unsigned int *data)
{
data[1] = inl(dev->iobase + PCI9118_DI) & 0xf;
/*
* The digital inputs and outputs share the read register.
* bits [7:4] are the digital outputs
* bits [3:0] are the digital inputs
*/
data[1] = inl(dev->iobase + PCI9118_DIO_REG) & 0xf;
return insn->n;
}
@@ -577,8 +582,14 @@ static int pci9118_insn_bits_do(struct comedi_device *dev,
struct comedi_insn *insn,
unsigned int *data)
{
/*
* The digital outputs are set with the same register that
* the digital inputs and outputs are read from. But the
* outputs are set with bits [3:0] so we can simply write
* the s->state to set them.
*/
if (comedi_dio_update_state(s, data))
outl(s->state & 0x0f, dev->iobase + PCI9118_DO);
outl(s->state, dev->iobase + PCI9118_DIO_REG);
data[1] = s->state;
@@ -1695,7 +1706,7 @@ static int pci9118_reset(struct comedi_device *dev)
outl(devpriv->ao_data[0], dev->iobase + PCI9118_AO_REG(0));
outl(devpriv->ao_data[1], dev->iobase + PCI9118_AO_REG(1));
outl(0, dev->iobase + PCI9118_DO); /* reset digi outs to L */
outl(0, dev->iobase + PCI9118_DIO_REG); /* reset digi outs to L */
udelay(10);
inl(dev->iobase + PCI9118_AI_FIFO_REG);
outl(0, dev->iobase + PCI9118_DELFIFO); /* flush FIFO */