[PATCH 01/11] staging: comedi: core: introduce comedi_dio_insn_bits()

H Hartley Sweeten hsweeten at visionengravers.com
Wed Aug 28 20:26:53 UTC 2013


The (*insn_bits) functions for DIO and DO subdevices typically use
the subdevice 's->state' to hold the current state of the output
channels. The 'insn' passed to these functions, INSN_BITS, specifies
two parameters passed in the 'data'.

  data[0] = 'mask', the channels to update
  data[1] = 'bits', the new state for the channels

Introduce a helper function to handle this boilerplate.

The function returns:

  0 if there are no changes in the state

  1 if the driver needs to update the hardware to a new state

Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/staging/comedi/comedidev.h |  2 ++
 drivers/staging/comedi/drivers.c   | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 2e19f65..de36499 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -345,6 +345,8 @@ void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
 int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
 			   struct comedi_insn *, unsigned int *data,
 			   unsigned int mask);
+int comedi_dio_insn_bits(struct comedi_device *, struct comedi_subdevice *,
+			 struct comedi_insn *, unsigned int *data);
 
 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 317a821..2bbd9d0 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -190,6 +190,31 @@ int comedi_dio_insn_config(struct comedi_device *dev,
 }
 EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
 
+/**
+ * comedi_dio_insn_bits() - boilerplate (*insn_bits) for DIO and DO subdevices.
+ * @dev: comedi_device struct
+ * @s: comedi_subdevice struct
+ * @insn: comedi_insn struct
+ * @data: parameters for the @insn
+ */
+int comedi_dio_insn_bits(struct comedi_device *dev,
+			 struct comedi_subdevice *s,
+			 struct comedi_insn *insn,
+			 unsigned int *data)
+{
+	unsigned int mask = data[0];
+	unsigned int bits = data[1];
+
+	if (mask) {
+		s->state &= ~mask;
+		s->state |= (bits & mask);
+
+		return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_insn_bits);
+
 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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