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Message-Id: <1442941359-19742-3-git-send-email-abbotti@mev.co.uk>
Date: Tue, 22 Sep 2015 18:02:39 +0100
From: Ian Abbott <abbotti@....co.uk>
To: <driverdev-devel@...uxdriverproject.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Ian Abbott <abbotti@....co.uk>,
H Hartley Sweeten <hsweeten@...ionengravers.com>,
<linux-kernel@...r.kernel.org>
Subject: [PATCH 2/2] staging: comedi: comedi_buf.c: document remaining exported functions
Add kernel-doc headers to the remaining functions marked for export.
Signed-off-by: Ian Abbott <abbotti@....co.uk>
---
drivers/staging/comedi/comedi_buf.c | 69 ++++++++++++++++++++++++++++++++++---
1 file changed, 65 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index 63553d9..d45a4b6 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -253,7 +253,17 @@ static unsigned int comedi_buf_write_n_available(struct comedi_subdevice *s)
return free_end - async->buf_write_alloc_count;
}
-/* allocates chunk for the writer from free buffer space */
+/**
+ * comedi_buf_write_alloc() - Reserve buffer space for writing
+ * @s: COMEDI subdevice.
+ * @nbytes: Maximum space to reserve in bytes.
+ *
+ * Reserve up to @nbytes bytes of space to be written in the COMEDI acquisition
+ * data buffer associated with the subdevice. The amount reserved is limited
+ * by the space available.
+ *
+ * Return: The amount of space reserved in bytes.
+ */
unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s,
unsigned int nbytes)
{
@@ -329,7 +339,21 @@ unsigned int comedi_buf_write_n_allocated(struct comedi_subdevice *s)
return async->buf_write_alloc_count - async->buf_write_count;
}
-/* transfers a chunk from writer to filled buffer space */
+/**
+ * comedi_buf_write_free() - Free buffer space after it is written
+ * @s: COMEDI subdevice.
+ * @nbytes: Maximum space to free in bytes.
+ *
+ * Free up to @nbytes bytes of space previously reserved for writing in the
+ * COMEDI acquisition data buffer associated with the subdevice. The amount of
+ * space freed is limited to the amount that was reserved. The freed space is
+ * assumed to have been filled with sample data by the writer.
+ *
+ * If the samples in the freed space need to be "munged", do so here. The
+ * freed space becomes available for allocation by the reader.
+ *
+ * Return: The amount of space freed in bytes.
+ */
unsigned int comedi_buf_write_free(struct comedi_subdevice *s,
unsigned int nbytes)
{
@@ -349,6 +373,17 @@ unsigned int comedi_buf_write_free(struct comedi_subdevice *s,
}
EXPORT_SYMBOL_GPL(comedi_buf_write_free);
+/**
+ * comedi_buf_read_n_available() - Determine amount of readable buffer space
+ * @s: COMEDI subdevice.
+ *
+ * Determine the amount of readable buffer space in the COMEDI acquisition data
+ * buffer associated with the subdevice. The readable buffer space is that
+ * which has been freed by the writer and "munged" to the sample data format
+ * expected by COMEDI if necessary.
+ *
+ * Return: The amount of readable buffer space.
+ */
unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s)
{
struct comedi_async *async = s->async;
@@ -369,7 +404,21 @@ unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s)
}
EXPORT_SYMBOL_GPL(comedi_buf_read_n_available);
-/* allocates a chunk for the reader from filled (and munged) buffer space */
+/**
+ * comedi_buf_read_alloc() - Reserve buffer space for reading
+ * @s: COMEDI subdevice.
+ * @nbytes: Maximum space to reserve in bytes.
+ *
+ * Reserve up to @nbytes bytes of previously written and "munged" buffer space
+ * for reading in the COMEDI acquisition data buffer associated with the
+ * subdevice. The amount reserved is limited to the space available. The
+ * reader can read from the reserved space and then free it. A reader is also
+ * allowed to read from the space before reserving it as long as it determines
+ * the amount of readable data available, but the space needs to be marked as
+ * reserved before it can be freed.
+ *
+ * Return: The amount of space reserved in bytes.
+ */
unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s,
unsigned int nbytes)
{
@@ -397,7 +446,19 @@ static unsigned int comedi_buf_read_n_allocated(struct comedi_async *async)
return async->buf_read_alloc_count - async->buf_read_count;
}
-/* transfers control of a chunk from reader to free buffer space */
+/**
+ * comedi_buf_read_free() - Free buffer space after it has been read
+ * @s: COMEDI subdevice.
+ * @nbytes: Maximum space to free in bytes.
+ *
+ * Free up to @nbytes bytes of buffer space previously reserved for reading in
+ * the COMEDI acquisition data buffer associated with the subdevice. The
+ * amount of space freed is limited to the amount that was reserved.
+ *
+ * The freed space becomes available for allocation by the writer.
+ *
+ * Return: The amount of space freed in bytes.
+ */
unsigned int comedi_buf_read_free(struct comedi_subdevice *s,
unsigned int nbytes)
{
--
2.5.1
--
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