staging: comedi: drivers: introduce comedi_dio_insn_config()
DIO subdevices always handle the INSN_CONFIG_DIO_{INPUT,OUTPUT} instructions
to configure the DIO channels. They also always handle the INSN_CONFIG_DIO_QUERY
instruction to query the configuration of a DIO channel.
Introduce a helper function to handle the (*insn_config) boilerplate for
comedi DIO subdevices. This function has the same paramters as (*insn_config)
functions with an additional parameter to allow the caller to pass a 'mask'
value for grouped DIO channels.
This function returns:
0 if the instruction was successful but requires additional handling by
the caller (INSN_CONFIG_DIO_{INPUT,OUTPUT}
insn->n if the instruction was handled (INSN_CONFIG_DIO_QUERY)
-EINVAL for all unhandled instructions
The caller is responsible for actually configuring the hardware based on
the configuration (s->io_bits).
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 791a26b..60fd81c 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -150,6 +150,46 @@
return -EINVAL;
}
+/**
+ * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices.
+ * @dev: comedi_device struct
+ * @s: comedi_subdevice struct
+ * @insn: comedi_insn struct
+ * @data: parameters for the @insn
+ * @mask: io_bits mask for grouped channels
+ */
+int comedi_dio_insn_config(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned int *data,
+ unsigned int mask)
+{
+ unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
+
+ if (!mask)
+ mask = chan_mask;
+
+ switch (data[0]) {
+ case INSN_CONFIG_DIO_INPUT:
+ s->io_bits &= ~mask;
+ break;
+
+ case INSN_CONFIG_DIO_OUTPUT:
+ s->io_bits |= mask;
+ break;
+
+ case INSN_CONFIG_DIO_QUERY:
+ data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
+ return insn->n;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
+
static int insn_rw_emulate_bits(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)