The control register for the parallel port is readable so there is no need
to cache the current value in the private data.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/comedi_parport.c | 34 ++++++++++++++-----------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/drivers/staging/comedi/drivers/comedi_parport.c
b/drivers/staging/comedi/drivers/comedi_parport.c
index 7180b0c..3944c19 100644
--- a/drivers/staging/comedi/drivers/comedi_parport.c
+++ b/drivers/staging/comedi/drivers/comedi_parport.c
@@ -92,7 +92,6 @@ pin, which can be used to wake up tasks.
#define PARPORT_CTRL_BIDIR_ENA (1 << 5)
struct parport_private {
- unsigned int c_data;
int enable_irq;
};
@@ -114,18 +113,19 @@ static int parport_data_reg_insn_config(struct
comedi_device *dev,
struct comedi_insn *insn,
unsigned int *data)
{
- struct parport_private *devpriv = dev->private;
+ unsigned int ctrl;
int ret;
ret = comedi_dio_insn_config(dev, s, insn, data, 0xff);
if (ret)
return ret;
+ ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
if (s->io_bits)
- devpriv->c_data &= ~PARPORT_CTRL_BIDIR_ENA;
+ ctrl &= ~PARPORT_CTRL_BIDIR_ENA;
else
- devpriv->c_data |= PARPORT_CTRL_BIDIR_ENA;
- outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
+ ctrl |= PARPORT_CTRL_BIDIR_ENA;
+ outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
return insn->n;
}
@@ -145,12 +145,13 @@ static int parport_ctrl_reg_insn_bits(struct
comedi_device *dev,
struct comedi_insn *insn,
unsigned int *data)
{
- struct parport_private *devpriv = dev->private;
+ unsigned int ctrl;
if (comedi_dio_insn_bits(dev, s, insn, data)) {
- devpriv->c_data &= ~((1 << s->n_chan) - 1);
- devpriv->c_data |= s->state;
- outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
+ ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
+ ctrl &= (PARPORT_CTRL_IRQ_ENA | PARPORT_CTRL_BIDIR_ENA);
+ ctrl |= s->state;
+ outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
}
data[1] = s->state;
@@ -212,9 +213,11 @@ static int parport_intr_cmd(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct parport_private *devpriv = dev->private;
+ unsigned int ctrl;
- devpriv->c_data |= PARPORT_CTRL_IRQ_ENA;
- outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
+ ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
+ ctrl |= PARPORT_CTRL_IRQ_ENA;
+ outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
devpriv->enable_irq = 1;
@@ -225,9 +228,11 @@ static int parport_intr_cancel(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct parport_private *devpriv = dev->private;
+ unsigned int ctrl;
- devpriv->c_data &= ~PARPORT_CTRL_IRQ_ENA;
- outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
+ ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
+ ctrl &= ~PARPORT_CTRL_IRQ_ENA;
+ outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
devpriv->enable_irq = 0;
@@ -323,8 +328,7 @@ static int parport_attach(struct comedi_device *dev,
}
outb(0, dev->iobase + PARPORT_DATA_REG);
- devpriv->c_data = 0;
- outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
+ outb(0, dev->iobase + PARPORT_CTRL_REG);
return 0;
}
--
1.8.3.2
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