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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 11:27:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 11:27:48 -0800
commit68c5735eaa5e680e701c9a2d1e3c7880bdf5ab66 (patch)
tree4f584693638bf257b66a1646cc30d823cacc0a58 /include/media/dvb_ringbuffer.h
parent2246edfaf88dc368e8671b04afd54412625df60a (diff)
parent273caa260035c03d89ad63d72d8cd3d9e5c5e3f1 (diff)
Merge tag 'media/v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - videobuf2 was moved to a media/common dir, as it is now used by the DVB subsystem too - Digital TV core memory mapped support interface - new sensor driver: ov7740 - several improvements at ddbridge driver - new V4L2 driver: IPU3 CIO2 CSI-2 receiver unit, found on some Intel SoCs - new tuner driver: tda18250 - finally got rid of all LIRC staging drivers - as we don't have old lirc drivers anymore, restruct the lirc device code - add support for UVC metadata - add a new staging driver for NVIDIA Tegra Video Decoder Engine - DVB kAPI headers moved to include/media - synchronize the kAPI and uAPI for the DVB subsystem, removing the gap for non-legacy APIs - reduce the kAPI gap for V4L2 - lots of other driver enhancements, cleanups, etc. * tag 'media/v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (407 commits) media: v4l2-compat-ioctl32.c: make ctrl_is_pointer work for subdevs media: v4l2-compat-ioctl32.c: refactor compat ioctl32 logic media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors media: v4l2-compat-ioctl32.c: drop pr_info for unknown buffer type media: v4l2-compat-ioctl32.c: copy clip list in put_v4l2_window32 media: v4l2-compat-ioctl32.c: fix ctrl_is_pointer media: v4l2-compat-ioctl32.c: copy m.userptr in put_v4l2_plane32 media: v4l2-compat-ioctl32.c: avoid sizeof(type) media: v4l2-compat-ioctl32.c: move 'helper' functions to __get/put_v4l2_format32 media: v4l2-compat-ioctl32.c: fix the indentation media: v4l2-compat-ioctl32.c: add missing VIDIOC_PREPARE_BUF media: v4l2-ioctl.c: don't copy back the result for -ENOTTY media: v4l2-ioctl.c: use check_fmt for enum/g/s/try_fmt media: vivid: fix module load error when enabling fb and no_error_inj=1 media: dvb_demux: improve debug messages media: dvb_demux: Better handle discontinuity errors media: cxusb, dib0700: ignore XC2028_I2C_FLUSH media: ts2020: avoid integer overflows on 32 bit machines media: i2c: ov7740: use gpio/consumer.h instead of gpio.h media: entity: Add a nop variant of media_entity_cleanup ...
Diffstat (limited to 'include/media/dvb_ringbuffer.h')
-rw-r--r--include/media/dvb_ringbuffer.h280
1 files changed, 280 insertions, 0 deletions
diff --git a/include/media/dvb_ringbuffer.h b/include/media/dvb_ringbuffer.h
new file mode 100644
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--- /dev/null
+++ b/include/media/dvb_ringbuffer.h
@@ -0,0 +1,280 @@
+/*
+ *
+ * dvb_ringbuffer.h: ring buffer implementation for the dvb driver
+ *
+ * Copyright (C) 2003 Oliver Endriss
+ * Copyright (C) 2004 Andrew de Quincey
+ *
+ * based on code originally found in av7110.c & dvb_ci.c:
+ * Copyright (C) 1999-2003 Ralph Metzler & Marcus Metzler
+ * for convergence integrated media GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#ifndef _DVB_RINGBUFFER_H_
+#define _DVB_RINGBUFFER_H_
+
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+
+/**
+ * struct dvb_ringbuffer - Describes a ring buffer used at DVB framework
+ *
+ * @data: Area were the ringbuffer data is written
+ * @size: size of the ringbuffer
+ * @pread: next position to read
+ * @pwrite: next position to write
+ * @error: used by ringbuffer clients to indicate that an error happened.
+ * @queue: Wait queue used by ringbuffer clients to indicate when buffer
+ * was filled
+ * @lock: Spinlock used to protect the ringbuffer
+ */
+struct dvb_ringbuffer {
+ u8 *data;
+ ssize_t size;
+ ssize_t pread;
+ ssize_t pwrite;
+ int error;
+
+ wait_queue_head_t queue;
+ spinlock_t lock;
+};
+
+#define DVB_RINGBUFFER_PKTHDRSIZE 3
+
+/**
+ * dvb_ringbuffer_init - initialize ring buffer, lock and queue
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @data: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ */
+extern void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_empty - test whether buffer is empty
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_free - returns the number of free bytes in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Return: number of free bytes in the buffer
+ */
+extern ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_avail - returns the number of bytes waiting in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Return: number of bytes waiting in the buffer
+ */
+extern ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_reset - resets the ringbuffer to initial state
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Resets 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);
+
+/*
+ * read routines & macros
+ */
+
+/**
+ * dvb_ringbuffer_flush - flush buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_flush_spinlock_wakeup- flush buffer protected by spinlock
+ * and wake-up waiting task(s)
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf);
+
+/**
+ * DVB_RINGBUFFER_PEEK - peek at byte @offs in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @offs: offset inside the ringbuffer
+ */
+#define DVB_RINGBUFFER_PEEK(rbuf, offs) \
+ ((rbuf)->data[((rbuf)->pread + (offs)) % (rbuf)->size])
+
+/**
+ * DVB_RINGBUFFER_SKIP - advance read ptr by @num bytes
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @num: number of bytes to advance
+ */
+#define DVB_RINGBUFFER_SKIP(rbuf, num) {\
+ (rbuf)->pread = ((rbuf)->pread + (num)) % (rbuf)->size;\
+}
+
+/**
+ * dvb_ringbuffer_read_user - Reads a buffer into a user pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the userspace. So,
+ * it will internally call copy_to_user().
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf,
+ u8 __user *buf, size_t len);
+
+/**
+ * dvb_ringbuffer_read - Reads a buffer into a pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the Kernel space
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf,
+ u8 *buf, size_t len);
+
+/*
+ * write routines & macros
+ */
+
+/**
+ * DVB_RINGBUFFER_WRITE_BYTE - write single byte to ring buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @byte: byte to write
+ */
+#define DVB_RINGBUFFER_WRITE_BYTE(rbuf, byte) \
+ { (rbuf)->data[(rbuf)->pwrite] = (byte); \
+ (rbuf)->pwrite = ((rbuf)->pwrite + 1) % (rbuf)->size; }
+
+/**
+ * dvb_ringbuffer_write - Writes a buffer into the ringbuffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be read
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the Kernel space
+ *
+ * return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_write_user - Writes a buffer received via a user pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be read
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the userspace. So,
+ * it will internally call copy_from_user().
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
+ const u8 __user *buf, size_t len);
+
+/**
+ * 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).
+ *
+ * Return: Number of bytes written, or -EFAULT, -ENOMEM, -EVINAL.
+ */
+extern ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8 *buf,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_read_user - Read from a packet 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.
+ *
+ * Return: Number of bytes read, or -EFAULT.
+ *
+ * .. 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.
+ */
+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.
+ *
+ * Return: 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);
+
+/**
+ * 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().
+ */
+extern void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx);
+
+/**
+ * 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.
+ * 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);
+
+#endif /* _DVB_RINGBUFFER_H_ */