media: media/pci: fix kerneldoc issues in two headers

This fixes these kerneldoc warnings:

drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'v4l2_dev' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'snd_card' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'name' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'type' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'dma_mode' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'pci_dev' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'mmio' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'dma_ops' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'video_channels' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'audio_channels' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'audio_rate' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'period_size' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'audio_enabled' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'dma_delay_timer' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'pending_dma_en' not described in 'tw686x_dev'
drivers/media/pci/tw686x/tw686x.h:143: warning: Function parameter or member 'pending_dma_cmd' not described in 'tw686x_dev'
drivers/media/pci/sta2x11/sta2x11_vip.h:25: warning: Function parameter or member 'i2c_id' not described in 'vip_config'
drivers/media/pci/sta2x11/sta2x11_vip.h:25: warning: Function parameter or member 'i2c_addr' not described in 'vip_config'

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 107 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[media] media/pci/tw686x: convert driver to use the new vb2_queue dev field

Stop using alloc_ctx and just fill in the device pointer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] tw686x: audio: Prevent hw param changes while busy

Audio hw params are shared across all DMA channels,
so if the user changes any of these while any DMA channel is
enabled, it will impact the enabled channels, potentially causing
serious instability issues.

This commit avoids such situation, by preventing any hw param
change (on any DMA channel) if any other DMA audio channel is capturing.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] tw686x: audio: Allow to configure the period size

Currently, the driver has a fixed period size of 4096 bytes
(2048 frames). Since this hardware can configure the audio
capture size, this commit allows a period size range of [512-4096].

This is very useful to reduce the audio latency.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] tw686x: Add support for DMA scatter-gather mode

Now that the driver has the infrastructure to support more
DMA modes, let's add the DMA scatter-gather mode.

In this mode, the device delivers sequential top-bottom
frames. The scatter-gather logic is based on staging's
tw686x-kh driver (by Krzysztof Ha?asa).

Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] tw686x: Add support for DMA contiguous interlaced frame mode

Now that the driver has the infrastructure to support more
DMA modes, let's add the DMA contiguous interlaced frame mode.

In this mode, the DMA P and B buffers are programmed with
the user-provided buffers. When a P (or B) frame is ready,
a new buffer is dequeued into P (or B).

In addition to interlaced fields, the device can also be
programmed to deliver alternate fields. Only interlaced
mode is supported for now.

Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] tw686x: Introduce an interface to support multiple DMA modes

Let's set the corner stone to support all the DMA modes
available on this device.

For stability reasons, the driver is currently setting DMA frame
mode, and using single DMA buffers to get the P and B buffers.
Each frame is then memcpy'ed into the user buffer.

However, other platforms might be interested in avoiding this
memcpy, or in taking advantage of the chip's DMA scatter-gather
capabilities.

To achieve this, this commit introduces a "dma_mode" module parameter,
and a tw686x_dma_ops struct. This will allow to define functions to
alloc/free DMA buffers, and to return the frames to userspace.

The memcpy-based method described above is named as dma_mode="memcpy".
Current alloc/free functions are renamed as tw686x_memcpy_xxx,
and are now used through a memcpy_dma_ops.

Tested-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Support Intersil/Techwell TW686x-based video capture cards

This commit introduces the support for the Techwell TW686x video
capture IC. This hardware supports a few DMA modes, including
scatter-gather and frame (contiguous).

This commit makes little use of the DMA engine and instead has
a memcpy based implementation. DMA frame and scatter-gather modes
support may be added in the future.

Currently supported chips:
- TW6864 (4 video channels),
- TW6865 (4 video channels, not tested, second generation chip),
- TW6868 (8 video channels but only 4 first channels using
built-in video decoder are supported, not tested),
- TW6869 (8 video channels, second generation chip).

[mchehab@osg.samsung.com: make checkpatch happy by using "unsigned int"
instead of just "unsigned"]
Cc: Krzysztof Halasa <khalasa@piap.pl>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>