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authorMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-08-22 07:38:51 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-08-22 09:05:45 -0300
commit2a86e373e0cf926f5cb41725f1b0ce3874e7b1cf (patch)
treecdcceda3065e1d219765900f2235b6937f0ff473 /drivers/media/dvb-core
parente08bb6f79fa0b9bf94ea44a306d1528172d788af (diff)
[media] DocBook: add dvb_ringbuffer.h to documentation
There are already some comments at dvb_ringbuffer.h that are ready for DocBook, although not properly formatted. Convert them, fix some issues and add this file to the device-drivers DocBook. While here, put multi-line comments on the right format. Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Acked-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'drivers/media/dvb-core')
-rw-r--r--drivers/media/dvb-core/dvb_ringbuffer.h135
1 files changed, 75 insertions, 60 deletions
diff --git a/drivers/media/dvb-core/dvb_ringbuffer.h b/drivers/media/dvb-core/dvb_ringbuffer.h
index 9e1e11b7c39c..3ebc2d34b4a2 100644
--- a/drivers/media/dvb-core/dvb_ringbuffer.h
+++ b/drivers/media/dvb-core/dvb_ringbuffer.h
@@ -45,33 +45,33 @@ struct dvb_ringbuffer {
/*
-** Notes:
-** ------
-** (1) For performance reasons read and write routines don't check buffer sizes
-** and/or number of bytes free/available. This has to be done before these
-** routines are called. For example:
-**
-** *** write <buflen> bytes ***
-** free = dvb_ringbuffer_free(rbuf);
-** if (free >= buflen)
-** count = dvb_ringbuffer_write(rbuf, buffer, buflen);
-** else
-** ...
-**
-** *** read min. 1000, max. <bufsize> bytes ***
-** avail = dvb_ringbuffer_avail(rbuf);
-** if (avail >= 1000)
-** count = dvb_ringbuffer_read(rbuf, buffer, min(avail, bufsize));
-** else
-** ...
-**
-** (2) If there is exactly one reader and one writer, there is no need
-** to lock read or write operations.
-** Two or more readers must be locked against each other.
-** Flushing the buffer counts as a read operation.
-** Resetting the buffer counts as a read and write operation.
-** Two or more writers must be locked against each other.
-*/
+ * Notes:
+ * ------
+ * (1) For performance reasons read and write routines don't check buffer sizes
+ * and/or number of bytes free/available. This has to be done before these
+ * routines are called. For example:
+ *
+ * *** write @buflen: bytes ***
+ * free = dvb_ringbuffer_free(rbuf);
+ * if (free >= buflen)
+ * count = dvb_ringbuffer_write(rbuf, buffer, buflen);
+ * else
+ * ...
+ *
+ * *** read min. 1000, max. @bufsize: bytes ***
+ * avail = dvb_ringbuffer_avail(rbuf);
+ * if (avail >= 1000)
+ * count = dvb_ringbuffer_read(rbuf, buffer, min(avail, bufsize));
+ * else
+ * ...
+ *
+ * (2) If there is exactly one reader and one writer, there is no need
+ * to lock read or write operations.
+ * Two or more readers must be locked against each other.
+ * Flushing the buffer counts as a read operation.
+ * Resetting the buffer counts as a read and write operation.
+ * Two or more writers must be locked against each other.
+ */
/* initialize ring buffer, lock and queue */
extern void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len);
@@ -87,9 +87,9 @@ extern ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf);
/*
-** Reset the read and write pointers to zero and flush the buffer
-** This counts as a read and write operation
-*/
+ * Reset the read and write pointers to zero and flush the buffer
+ * This counts as a read and write operation
+ */
extern void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf);
@@ -101,19 +101,19 @@ extern void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf);
/* flush buffer protected by spinlock and wake-up waiting task(s) */
extern void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf);
-/* peek at byte <offs> in the buffer */
+/* peek at byte @offs: in the buffer */
#define DVB_RINGBUFFER_PEEK(rbuf,offs) \
(rbuf)->data[((rbuf)->pread+(offs))%(rbuf)->size]
-/* advance read ptr by <num> bytes */
+/* advance read ptr by @num: bytes */
#define DVB_RINGBUFFER_SKIP(rbuf,num) \
(rbuf)->pread=((rbuf)->pread+(num))%(rbuf)->size
/*
-** read <len> bytes from ring buffer into <buf>
-** <usermem> specifies whether <buf> resides in user space
-** returns number of bytes transferred or -EFAULT
-*/
+ * read @len: bytes from ring buffer into @buf:
+ * @usermem: specifies whether @buf: resides in user space
+ * returns number of bytes transferred or -EFAULT
+ */
extern ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf,
u8 __user *buf, size_t len);
extern void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf,
@@ -127,9 +127,9 @@ extern void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf,
{ (rbuf)->data[(rbuf)->pwrite]=(byte); \
(rbuf)->pwrite=((rbuf)->pwrite+1)%(rbuf)->size; }
/*
-** write <len> bytes to ring buffer
-** <usermem> specifies whether <buf> resides in user space
-** returns number of bytes transferred or -EFAULT
+ * write @len: bytes to ring buffer
+ * @usermem: specifies whether @buf: resides in user space
+ * returns number of bytes transferred or -EFAULT
*/
extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf,
size_t len);
@@ -138,48 +138,63 @@ extern ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
/**
- * Write a packet into the ringbuffer.
+ * dvb_ringbuffer_pkt_write - Write a packet into the ringbuffer.
*
- * <rbuf> Ringbuffer to write to.
- * <buf> Buffer to write.
- * <len> Length of buffer (currently limited to 65535 bytes max).
+ * @rbuf: Ringbuffer to write to.
+ * @buf: Buffer to write.
+ * @len: Length of buffer (currently limited to 65535 bytes max).
* returns Number of bytes written, or -EFAULT, -ENOMEM, -EVINAL.
*/
extern ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf,
size_t len);
/**
- * Read from a packet in the ringbuffer. Note: unlike dvb_ringbuffer_read(), this
- * does NOT update the read pointer in the ringbuffer. You must use
- * dvb_ringbuffer_pkt_dispose() to mark a packet as no longer required.
- *
- * <rbuf> Ringbuffer concerned.
- * <idx> Packet index as returned by dvb_ringbuffer_pkt_next().
- * <offset> Offset into packet to read from.
- * <buf> Destination buffer for data.
- * <len> Size of destination buffer.
- * <usermem> Set to 1 if <buf> is in userspace.
+ * dvb_ringbuffer_pkt_read_user - Read from a packet in the ringbuffer.
+ * Note: unlike dvb_ringbuffer_read(), this does NOT update the read pointer
+ * in the ringbuffer. You must use dvb_ringbuffer_pkt_dispose() to mark a
+ * packet as no longer required.
+ *
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
+ * @offset: Offset into packet to read from.
+ * @buf: Destination buffer for data.
+ * @len: Size of destination buffer.
+ *
* returns Number of bytes read, or -EFAULT.
*/
extern ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf, size_t idx,
int offset, u8 __user *buf, size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_read - Read from a packet in the ringbuffer.
+ * Note: unlike dvb_ringbuffer_read_user(), this DOES update the read pointer
+ * in the ringbuffer.
+ *
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
+ * @offset: Offset into packet to read from.
+ * @buf: Destination buffer for data.
+ * @len: Size of destination buffer.
+ *
+ * returns Number of bytes read, or -EFAULT.
+ */
extern ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
int offset, u8 *buf, size_t len);
/**
- * Dispose of a packet in the ring buffer.
+ * dvb_ringbuffer_pkt_dispose - Dispose of a packet in the ring buffer.
*
- * <rbuf> Ring buffer concerned.
- * <idx> Packet index as returned by dvb_ringbuffer_pkt_next().
+ * @rbuf: Ring buffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
*/
extern void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx);
/**
- * Get the index of the next packet in a ringbuffer.
+ * dvb_ringbuffer_pkt_next - Get the index of the next packet in a ringbuffer.
*
- * <rbuf> Ringbuffer concerned.
- * <idx> Previous packet index, or -1 to return the first packet index.
- * <pktlen> On success, will be updated to contain the length of the packet in bytes.
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Previous packet index, or -1 to return the first packet index.
+ * @pktlen: On success, will be updated to contain the length of the packet in bytes.
* returns Packet index (if >=0), or -1 if no packets available.
*/
extern ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen);

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