Remove the need for the 'output_bits' in the private data by just
reading the current state of the data port when updating the output
channels in the (*insn_bits) function.
Rename the local variable 'port_read_bits' to 'bits' so that we can
use it for updating the output channels and reading back the actual
state to return to the user.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gr...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/ni_65xx.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_65xx.c
b/drivers/staging/comedi/drivers/ni_65xx.c
index 1f3e83b..8c0f5d3 100644
--- a/drivers/staging/comedi/drivers/ni_65xx.c
+++ b/drivers/staging/comedi/drivers/ni_65xx.c
@@ -260,7 +260,6 @@ static inline unsigned ni_65xx_total_num_ports(const struct
ni_65xx_board
struct ni_65xx_private {
void __iomem *mmio;
- unsigned short output_bits[NI_65XX_MAX_NUM_PORTS];
};
struct ni_65xx_subdevice_private {
@@ -356,7 +355,7 @@ static int ni_65xx_dio_insn_bits(struct comedi_device *dev,
port_offset <= last_port_offset; port_offset++) {
unsigned port = sprivate(s)->base_port + port_offset;
int base_port_channel = port_offset * ni_65xx_channels_per_port;
- unsigned port_mask, port_data, port_read_bits;
+ unsigned port_mask, port_data, bits;
int bitshift = base_port_channel - base_bitfield_channel;
if (bitshift >= 32)
@@ -372,22 +371,23 @@ static int ni_65xx_dio_insn_bits(struct comedi_device
*dev,
}
port_mask &= 0xff;
port_data &= 0xff;
+
+ /* update the outputs */
if (port_mask) {
- unsigned bits;
- devpriv->output_bits[port] &= ~port_mask;
- devpriv->output_bits[port] |=
- port_data & port_mask;
- bits = devpriv->output_bits[port];
+ bits = readb(devpriv->mmio + NI_65XX_IO_DATA_REG(port));
+ bits &= ~port_mask;
+ bits |= (port_data & port_mask);
writeb(bits, devpriv->mmio + NI_65XX_IO_DATA_REG(port));
}
- port_read_bits = readb(devpriv->mmio +
- NI_65XX_IO_DATA_REG(port));
+
+ /* now read back the actual state */
+ bits = readb(devpriv->mmio + NI_65XX_IO_DATA_REG(port));
if (bitshift > 0)
- port_read_bits <<= bitshift;
+ bits <<= bitshift;
else
- port_read_bits >>= -bitshift;
+ bits >>= -bitshift;
- read_bits |= port_read_bits;
+ read_bits |= bits;
}
data[1] = read_bits;
return insn->n;
--
1.9.3
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