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>
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>
Now that we've introduced the dma_mode parameter to pick the
DMA operation, let's use it to also select the audio DMA
operation.
When dma_mode != memcpy, the driver will avoid using memcpy
in the audio capture path, and the DMA hardware operation
will act directly on the ALSA buffers.
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>
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>
