- 19 Jul, 2017 33 commits
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Sakari Ailus authored
The function to parse CSI2 bus parameters was called v4l2_fwnode_endpoint_parse_csi_bus(), rename it as v4l2_fwnode_endpoint_parse_csi2_bus() in anticipation of CSI1/CCP2 support. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Sakari Ailus authored
Document the CSI1/CCP2 property strobe. It signifies the clock or strobe mode. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Sebastian Reichel <sre@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Sakari Ailus authored
In the vast majority of cases the bus type is known to the driver(s) since a receiver or transmitter can only support a single one. There are cases however where different options are possible, or the bus type cannot be automatically detected. The existing V4L2 OF support tries to figure out the bus type and parse the bus parameters based on that. This does not scale too well as there are multiple serial busses that share common properties. Some hardware also supports multiple types of busses on the same interfaces. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Sebastian Reichel <sre@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
If an encoder stop command is issued after the output queue has already stopped streaming, the qsequence counter has been reset to 0. Always wake up the capture queue if the output queue is not streaming. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
Firmware versions 2.3.10 revision 40778 and 3.1.1 revision 46072 are contained in the i.MX firmware download archives provided by NXP at http://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-3.5.7-1.0.0.bin and http://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-5.4.bin, respectively. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
Explicitly set MPEG-4 encoder class register instead of relying on the default value of 0. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
This fixes visual artifacts in the first macroblock row of encoded MPEG-4 video output caused by 8 additional lines of luma data leaking into the chroma planes of the internal reference framebuffers: the buffer size is rounded up to a multiple of 16x16 macroblock size, same as for the h.264 encoder. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
Set the field of destination buffers properly. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
CodaDx6 only accepts GOP sizes up to 60 frames, but CODA960 can handle up to 99 frames. If we disable automatic I frame generation altogether by setting GOP size to 0, we can let an application produce arbitrarily large I frame intervals using the V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME control. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
This smatch warning: coda/coda-common.c:706 coda_s_fmt() warn: missing break? reassigning 'ctx->tiled_map_type' can be silenced by moving the ctx->tiled_map_type assignment into the breakout condition. That way the field is not reassigned when falling through to the next switch statement. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Philipp Zabel authored
CODA7541 supports H.264 BP level 3/3.1 and MPEG-4 SP level 5/6. CODA960 supports H.264 BP level 4.0 and MPEG-4 SP level 5/6. Implement the necessary profile and level controls to let userspace know this. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Kevin Hilman authored
Fix potential NULL pointer dereference in the error path of memory allocation failure. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Kevin Hilman <khilman@baylibre.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Colin Ian King authored
Don't populate the gain tables on the stack but make them static const. Makes the object code smaller: Before: text data bss dec hex filename 7801 1408 0 9209 23f9 drivers/media/tuners/fc0012.o 8483 936 0 9419 24cb drivers/media/tuners/fc0013.o After: text data bss dec hex filename 7696 1464 0 9160 23c8 drivers/media/tuners/fc0012.o 8362 1024 0 9386 24aa drivers/media/tuners/fc0013.o Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Colin Ian King authored
Don't populate const array saa7128_regs_ntsc on the stack but insteaed make it static. Makes the object code smaller and saves nearly 840 bytes Before: text data bss dec hex filename 9218 360 0 9578 256a solo6x10-tw28.o After: text data bss dec hex filename 8237 504 0 8741 2225 solo6x10-tw28.o Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Andrey Utkin <andrey_utkin@fastmail.com> Signed-off-by: Ismael Luceno <ismael@iodev.co.uk> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Arnd Bergmann authored
When CONFIG_V4L2 is built as a loadable module, the new video mux driver fails to link as built-in code: drivers/media/platform/video-mux.o: In function `video_mux_remove': video-mux.c:(.text+0x24): undefined reference to `v4l2_async_unregister_subdev' drivers/media/platform/video-mux.o: In function `video_mux_probe': video-mux.c:(.text+0x800): undefined reference to `v4l2_subdev_init' video-mux.c:(.text+0xa10): undefined reference to `v4l2_async_register_subdev' This makes it use the same Kconfig dependency as all the other users of the VIDEO_V4L2_SUBDEV_API symbol. Fixes: 68803ad4 ("[media] platform: add video-multiplexer subdevice driver") Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Acked-by: Hugues Fruchet <hugues.fruchet@st.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Check for vb2_ops structures that are only stored in the ops field of a vb2_queue structure. That field is declared const, so vb2_ops structures that have this property can be declared as const also. This issue was detected using Coccinelle and the following semantic patch: @r disable optional_qualifier@ identifier i; position p; @@ static struct vb2_ops i@p = { ... }; @ok@ identifier r.i; struct vb2_queue e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct vb2_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct vb2_ops i = { ... }; Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Acked-by: Hugues Fruchet <hugues.fruchet@st.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Gustavo A. R. Silva authored
Remove unnecessary static on local variable t_params. Such variable is initialized before being used, on every execution path throughout the function. The static has no benefit and, removing it reduces the code size. This issue was detected using Coccinelle and the following semantic patch: @bad exists@ position p; identifier x; type T; @@ static T x@p; ... x = <+...x...+> @@ identifier x; expression e; type T; position p != bad.p; @@ -static T x@p; ... when != x when strict ?x = e; In the following log you can see the difference in the code size. Also, there is a significant difference in the bss segment. This log is the output of the size command, before and after the code change: before: text data bss dec hex filename 23314 3640 832 27786 6c8a drivers/media/tuners/tuner-simple.o after: text data bss dec hex filename 23257 3552 768 27577 6bb9 drivers/media/tuners/tuner-simple.o Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Colin Ian King authored
Trivial fix to spelling mistake in v4l2_dbg debug message Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Colin Ian King authored
Trivial fix to spelling mistake in v4l2_info message Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Arvind Yadav authored
dma_buf_ops are not supposed to change at runtime. All functions working with dma_buf_ops provided by <linux/dma-buf.h> work with const dma_buf_ops. So mark the non-const structs as const. File size before: text data bss dec hex filename 5238 112 4 5354 14ea drivers/media/v4l2-core/videobuf2-dma-sg.o File size After adding 'const': text data bss dec hex filename 5358 0 4 5362 14f2 drivers/media/v4l2-core/videobuf2-dma-sg.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Arvind Yadav authored
dma_buf_ops are not supposed to change at runtime. All functions working with dma_buf_ops provided by <linux/dma-buf.h> work with const dma_buf_ops. So mark the non-const structs as const. File size before: text data bss dec hex filename 3171 192 0 3363 d23 drivers/media/v4l2-core/videobuf2-vmalloc.o File size After adding 'const': text data bss dec hex filename 3291 80 0 3371 d2b drivers/media/v4l2-core/videobuf2-vmalloc.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Arvind Yadav authored
dma_buf_ops are not supposed to change at runtime. All functions working with dma_buf_ops provided by <linux/dma-buf.h> work with const dma_buf_ops. So mark the non-const structs as const. File size before: text data bss dec hex filename 6035 272 0 6307 18a3 drivers/media/v4l2-core/videobuf2-dma-contig.o File size After adding 'const': text data bss dec hex filename 6155 160 0 6315 18ab drivers/media/v4l2-core/videobuf2-dma-contig.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Bhumika Goyal authored
Declare v4l2_file_operations structure as const as it is only stored in the fops field of video_device structure. This field is of type const, so declare v4l2_file_operations structures with similar properties as const. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Bhumika Goyal authored
Declare v4l2_file_operations structures as const as they are only stored in the fops field of video_device structures. This field is of type const, so declare v4l2_file_operations structures with similar properties as const. Cross compiled bfin_capture.o for blackfin arch. vpbe_display.o file did not cross compile for arm. Could not find any architecture matching the configuraion symbol for fsl-viu.c file. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Mauro Carvalho Chehab authored
/devel/v4l/patchwork/Documentation/media/kapi/cec-core.rst:369: WARNING: Title underline too short. CEC Notifier framework ----------------- Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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- 18 Jul, 2017 7 commits
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Hans Verkuil authored
The CEC adapter name used by the pulse8-cec and rainshadow-cec USB device drivers was a fixed string, but it should be unique if you connect multiple of these devices to the same computer. Use dev_name(&serio->dev) instead, which make it unique again. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
Especially the '0.10' version number is confusing since CEC_ADAP_G_CAPS returns a completely different version number. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
The cec_register_cec_notifier function was in media/cec.h, but it has to be in cec-notifier.h. While we are at it, also document it and add a stub function for when the notifier is disabled or the CEC core code is unreachable. Based on an earlier patch from Jose Abreu <Jose.Abreu@synopsys.com>. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
Document the persistent_config module option. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
Some hardware does more than one attempt. So when it calls cec_transmit_done when an error occurred it will e.g. use an error count of 2 instead of 1. The framework always assumed a single attempt, but now it is smarter and will sum the counters to detect how many attempts were made. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
Include the CEC pin framework documentation by reading cec-pin.h. Include the CEC notifier framework documentation by reading cec-notifier.h. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Hans Verkuil authored
Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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