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@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/comedidev.h | 4 ++++
drivers/staging/comedi/drivers.c | 40 ++++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 76a5c2b..2e19f65 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -342,6 +342,10 @@ void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
/* drivers.c - general comedi driver functions */
+int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
+ struct comedi_insn *, unsigned int *data,
+ unsigned int mask);
+
void *comedi_alloc_devpriv(struct comedi_device *, size_t);
int comedi_alloc_subdevices(struct comedi_device *, int);
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 @@ int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
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)
--
1.8.3.2
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