diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-06 11:27:48 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-06 11:27:48 -0800 |
commit | 68c5735eaa5e680e701c9a2d1e3c7880bdf5ab66 (patch) | |
tree | 4f584693638bf257b66a1646cc30d823cacc0a58 /include/media/dvb_ringbuffer.h | |
parent | 2246edfaf88dc368e8671b04afd54412625df60a (diff) | |
parent | 273caa260035c03d89ad63d72d8cd3d9e5c5e3f1 (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.h | 280 |
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 index 000000000000..8ed6bcc3a56e --- /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_ */ |