staging: comedi: dt9812: convert digital in subdevice to (*insn_bits)

Currently the (*insn_read) function for the digital input subdevice
returns the state for a single channel. It's more efficent to use
the (*insn_bits) function and return the state for all the channels.

The comedi core can use the (*insn_bits) to emulate the (*insn_read)
if needed.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/dt9812.c b/drivers/staging/comedi/drivers/dt9812.c
index 1bc89cc6b08d1ecbb7f3c00167ec68d971b40454..4fd15162f4b60909c3f2177aa25d1d7562d03dd5 100644 (file)
--- a/drivers/staging/comedi/drivers/dt9812.c
+++ b/drivers/staging/comedi/drivers/dt9812.c
@@ -607,18 +607,21 @@ static int dt9812_analog_out(struct comedi_device *dev, int channel, u16 value)
        return ret;
 }
 
-static int dt9812_di_rinsn(struct comedi_device *dev,
-                          struct comedi_subdevice *s, struct comedi_insn *insn,
-                          unsigned int *data)
+static int dt9812_di_insn_bits(struct comedi_device *dev,
+                              struct comedi_subdevice *s,
+                              struct comedi_insn *insn,
+                              unsigned int *data)
 {
-       unsigned int channel = CR_CHAN(insn->chanspec);
-       int n;
        u8 bits = 0;
+       int ret;
 
-       dt9812_digital_in(dev, &bits);
-       for (n = 0; n < insn->n; n++)
-               data[n] = ((1 << channel) & bits) != 0;
-       return n;
+       ret = dt9812_digital_in(dev, &bits);
+       if (ret)
+               return ret;
+
+       data[1] = bits;
+
+       return insn->n;
 }
 
 static int dt9812_do_winsn(struct comedi_device *dev,
@@ -837,7 +840,7 @@ static int dt9812_auto_attach(struct comedi_device *dev,
        s->n_chan       = 8;
        s->maxdata      = 1;
        s->range_table  = &range_digital;
-       s->insn_read    = dt9812_di_rinsn;
+       s->insn_bits    = dt9812_di_insn_bits;
 
        /* Digital Output subdevice */
        s = &dev->subdevices[1];