| Message ID | 20220328141309.177611-7-xavier.roumegue@oss.nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i.MX8MP DW100 dewarper driver | expand |
On 28/03/2022 16:13, Xavier Roumegue wrote: > The DW100 driver gets the dewarping mapping as a binary blob from the > userspace application through a custom control. > The blob format is hardware specific so create a dedicated control for > this purpose. > > Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> > --- > Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ > include/uapi/linux/dw100.h | 11 +++++++++++ > 2 files changed, 23 insertions(+) > create mode 100644 include/uapi/linux/dw100.h > > diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst > index 4cd55c75628e..f6d684cadf26 100644 > --- a/Documentation/userspace-api/media/drivers/dw100.rst > +++ b/Documentation/userspace-api/media/drivers/dw100.rst > @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. > More details on the DW100 hardware operations can be found in > *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. > > +The Vivante DW100 m2m driver implements the following driver-specific control: > + > +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` (integer) -> (__u32 array) But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? > + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in > + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 > + dynamic array. The image is divided into many small 16x16 blocks. If the > + width of the image is not divisible by 16, the size of the rightmost block > + is the remainder. Isn't the same true for the height? The dewarping map only saves the vertex coordinates of the > + block. The dewarping grid map is comprised of vertex coordinates for x and y. > + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 fixed point' is better, but you also need to specify exactly where the bits are stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant bits, and the fractional part is stored in the 4 least significant bits of the __u16.' > + address, with the Y coordinate in the upper bits and X in the lower bits. And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' Or something along those lines. > + > .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM > diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h > new file mode 100644 > index 000000000000..7fdcf2bf42e5 > --- /dev/null > +++ b/include/uapi/linux/dw100.h > @@ -0,0 +1,11 @@ > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > +/* Copyright 2022 NXP */ > + > +#ifndef __UAPI_DW100_H__ > +#define __UAPI_DW100_H__ > + > +#include <linux/v4l2-controls.h> > + Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst documentation so users of this control know where to find the associated documentation. > +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) > + > +#endif Regards, Hans
On Mon, Apr 25, 2022 at 08:57:07AM +0200, Hans Verkuil wrote: > On 28/03/2022 16:13, Xavier Roumegue wrote: > > The DW100 driver gets the dewarping mapping as a binary blob from the > > userspace application through a custom control. > > The blob format is hardware specific so create a dedicated control for > > this purpose. > > > > Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> > > --- > > Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ > > include/uapi/linux/dw100.h | 11 +++++++++++ > > 2 files changed, 23 insertions(+) > > create mode 100644 include/uapi/linux/dw100.h > > > > diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst > > index 4cd55c75628e..f6d684cadf26 100644 > > --- a/Documentation/userspace-api/media/drivers/dw100.rst > > +++ b/Documentation/userspace-api/media/drivers/dw100.rst > > @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. > > More details on the DW100 hardware operations can be found in > > *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. > > > > +The Vivante DW100 m2m driver implements the following driver-specific control: > > + > > +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` > > (integer) -> (__u32 array) > > But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? > > > + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in > > + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 > > + dynamic array. The image is divided into many small 16x16 blocks. If the > > + width of the image is not divisible by 16, the size of the rightmost block > > + is the remainder. > > Isn't the same true for the height? > > The dewarping map only saves the vertex coordinates of the > > + block. The dewarping grid map is comprised of vertex coordinates for x and y. > > + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate > > As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 > fixed point' is better, but you also need to specify exactly where the bits are > stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant > bits, and the fractional part is stored in the 4 least significant bits of the __u16.' Isn't that implied ? I've never seen fixed-point numbers stored the other way around. Regarding the Q notation, while it was coined by TI, I think it's widespread enough to be used here. I don't mind much though. > > + address, with the Y coordinate in the upper bits and X in the lower bits. > > And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' > Or something along those lines. > > > + > > .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM > > diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h > > new file mode 100644 > > index 000000000000..7fdcf2bf42e5 > > --- /dev/null > > +++ b/include/uapi/linux/dw100.h > > @@ -0,0 +1,11 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > > +/* Copyright 2022 NXP */ > > + > > +#ifndef __UAPI_DW100_H__ > > +#define __UAPI_DW100_H__ > > + > > +#include <linux/v4l2-controls.h> > > + > > Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst > documentation so users of this control know where to find the associated > documentation. > > > +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) > > + > > +#endif
On 25/04/2022 09:11, Laurent Pinchart wrote: > On Mon, Apr 25, 2022 at 08:57:07AM +0200, Hans Verkuil wrote: >> On 28/03/2022 16:13, Xavier Roumegue wrote: >>> The DW100 driver gets the dewarping mapping as a binary blob from the >>> userspace application through a custom control. >>> The blob format is hardware specific so create a dedicated control for >>> this purpose. >>> >>> Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> >>> --- >>> Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ >>> include/uapi/linux/dw100.h | 11 +++++++++++ >>> 2 files changed, 23 insertions(+) >>> create mode 100644 include/uapi/linux/dw100.h >>> >>> diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst >>> index 4cd55c75628e..f6d684cadf26 100644 >>> --- a/Documentation/userspace-api/media/drivers/dw100.rst >>> +++ b/Documentation/userspace-api/media/drivers/dw100.rst >>> @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. >>> More details on the DW100 hardware operations can be found in >>> *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. >>> >>> +The Vivante DW100 m2m driver implements the following driver-specific control: >>> + >>> +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` >> >> (integer) -> (__u32 array) >> >> But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? >> >>> + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in >>> + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 >>> + dynamic array. The image is divided into many small 16x16 blocks. If the >>> + width of the image is not divisible by 16, the size of the rightmost block >>> + is the remainder. >> >> Isn't the same true for the height? >> >> The dewarping map only saves the vertex coordinates of the >>> + block. The dewarping grid map is comprised of vertex coordinates for x and y. >>> + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate >> >> As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 >> fixed point' is better, but you also need to specify exactly where the bits are >> stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant >> bits, and the fractional part is stored in the 4 least significant bits of the __u16.' > > Isn't that implied ? I've never seen fixed-point numbers stored the > other way around. True, perhaps that's overkill. > > Regarding the Q notation, while it was coined by TI, I think it's > widespread enough to be used here. I don't mind much though. I had to look it up :-) That might say more about me, though... I think the key phrase that is missing here is "fixed point". Regards, Hans > >>> + address, with the Y coordinate in the upper bits and X in the lower bits. >> >> And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' >> Or something along those lines. >> >>> + >>> .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM >>> diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h >>> new file mode 100644 >>> index 000000000000..7fdcf2bf42e5 >>> --- /dev/null >>> +++ b/include/uapi/linux/dw100.h >>> @@ -0,0 +1,11 @@ >>> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ >>> +/* Copyright 2022 NXP */ >>> + >>> +#ifndef __UAPI_DW100_H__ >>> +#define __UAPI_DW100_H__ >>> + >>> +#include <linux/v4l2-controls.h> >>> + >> >> Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst >> documentation so users of this control know where to find the associated >> documentation. >> >>> +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) >>> + >>> +#endif >
Hello Hans, On 4/25/22 09:38, Hans Verkuil wrote: > On 25/04/2022 09:11, Laurent Pinchart wrote: >> On Mon, Apr 25, 2022 at 08:57:07AM +0200, Hans Verkuil wrote: >>> On 28/03/2022 16:13, Xavier Roumegue wrote: >>>> The DW100 driver gets the dewarping mapping as a binary blob from the >>>> userspace application through a custom control. >>>> The blob format is hardware specific so create a dedicated control for >>>> this purpose. >>>> >>>> Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> >>>> --- >>>> Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ >>>> include/uapi/linux/dw100.h | 11 +++++++++++ >>>> 2 files changed, 23 insertions(+) >>>> create mode 100644 include/uapi/linux/dw100.h >>>> >>>> diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst >>>> index 4cd55c75628e..f6d684cadf26 100644 >>>> --- a/Documentation/userspace-api/media/drivers/dw100.rst >>>> +++ b/Documentation/userspace-api/media/drivers/dw100.rst >>>> @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. >>>> More details on the DW100 hardware operations can be found in >>>> *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. >>>> >>>> +The Vivante DW100 m2m driver implements the following driver-specific control: >>>> + >>>> +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` >>> >>> (integer) -> (__u32 array) >>> >>> But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? >>> >>>> + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in >>>> + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 >>>> + dynamic array. The image is divided into many small 16x16 blocks. If the >>>> + width of the image is not divisible by 16, the size of the rightmost block >>>> + is the remainder. >>> >>> Isn't the same true for the height? >>> >>> The dewarping map only saves the vertex coordinates of the >>>> + block. The dewarping grid map is comprised of vertex coordinates for x and y. >>>> + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate >>> >>> As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 >>> fixed point' is better, but you also need to specify exactly where the bits are >>> stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant >>> bits, and the fractional part is stored in the 4 least significant bits of the __u16.' >> >> Isn't that implied ? I've never seen fixed-point numbers stored the >> other way around. > > True, perhaps that's overkill. > >> >> Regarding the Q notation, while it was coined by TI, I think it's >> widespread enough to be used here. I don't mind much though. > > I had to look it up :-) > > That might say more about me, though... > > I think the key phrase that is missing here is "fixed point". I will then replace in the documentation and comments "UQ12.4" by "an unsigned 12.4 fixed point format (UQ12.4)". Considering that I am using "UQ12_4" in some symbol names, this might ease the overall code understanding. Regards, Xavier > Regards, > > Hans > >> >>>> + address, with the Y coordinate in the upper bits and X in the lower bits. >>> >>> And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' >>> Or something along those lines. >>> >>>> + >>>> .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM >>>> diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h >>>> new file mode 100644 >>>> index 000000000000..7fdcf2bf42e5 >>>> --- /dev/null >>>> +++ b/include/uapi/linux/dw100.h >>>> @@ -0,0 +1,11 @@ >>>> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ >>>> +/* Copyright 2022 NXP */ >>>> + >>>> +#ifndef __UAPI_DW100_H__ >>>> +#define __UAPI_DW100_H__ >>>> + >>>> +#include <linux/v4l2-controls.h> >>>> + >>> >>> Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst >>> documentation so users of this control know where to find the associated >>> documentation. >>> >>>> +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) >>>> + >>>> +#endif >> >
Hello Hans, On 4/25/22 08:57, Hans Verkuil wrote: > On 28/03/2022 16:13, Xavier Roumegue wrote: >> The DW100 driver gets the dewarping mapping as a binary blob from the >> userspace application through a custom control. >> The blob format is hardware specific so create a dedicated control for >> this purpose. >> >> Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> >> --- >> Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ >> include/uapi/linux/dw100.h | 11 +++++++++++ >> 2 files changed, 23 insertions(+) >> create mode 100644 include/uapi/linux/dw100.h >> >> diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst >> index 4cd55c75628e..f6d684cadf26 100644 >> --- a/Documentation/userspace-api/media/drivers/dw100.rst >> +++ b/Documentation/userspace-api/media/drivers/dw100.rst >> @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. >> More details on the DW100 hardware operations can be found in >> *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. >> >> +The Vivante DW100 m2m driver implements the following driver-specific control: >> + >> +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` > > (integer) -> (__u32 array) > > But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? This is indeed debatable. But the array is describing vertices positions on a 2D dimension space, and thus its size is always even. More importantly, the array must follow the format imposed by the hardware which expects __u16 pairs packed in a __u32. Lastly, the lut (map) register size unit is __u32. Hence, IMHO, using __u32 might make more sense to highlight its hardware dependency. > >> + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in >> + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 >> + dynamic array. The image is divided into many small 16x16 blocks. If the >> + width of the image is not divisible by 16, the size of the rightmost block >> + is the remainder. > > Isn't the same true for the height? Yes, will update accordingly. > > The dewarping map only saves the vertex coordinates of the >> + block. The dewarping grid map is comprised of vertex coordinates for x and y. >> + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate > > As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 > fixed point' is better, but you also need to specify exactly where the bits are > stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant > bits, and the fractional part is stored in the 4 least significant bits of the __u16.' > >> + address, with the Y coordinate in the upper bits and X in the lower bits. > > And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' > Or something along those lines. > >> + >> .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM >> diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h >> new file mode 100644 >> index 000000000000..7fdcf2bf42e5 >> --- /dev/null >> +++ b/include/uapi/linux/dw100.h >> @@ -0,0 +1,11 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ >> +/* Copyright 2022 NXP */ >> + >> +#ifndef __UAPI_DW100_H__ >> +#define __UAPI_DW100_H__ >> + >> +#include <linux/v4l2-controls.h> >> + > > Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst > documentation so users of this control know where to find the associated > documentation. > >> +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) >> + >> +#endif > > Regards, > > Hans Regards, Xavier
Hi Xavier, On Tue, Apr 26, 2022 at 11:34:55PM +0200, Xavier Roumegue (OSS) wrote: > On 4/25/22 08:57, Hans Verkuil wrote: > > On 28/03/2022 16:13, Xavier Roumegue wrote: > >> The DW100 driver gets the dewarping mapping as a binary blob from the > >> userspace application through a custom control. > >> The blob format is hardware specific so create a dedicated control for > >> this purpose. > >> > >> Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> > >> --- > >> Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ > >> include/uapi/linux/dw100.h | 11 +++++++++++ > >> 2 files changed, 23 insertions(+) > >> create mode 100644 include/uapi/linux/dw100.h > >> > >> diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst > >> index 4cd55c75628e..f6d684cadf26 100644 > >> --- a/Documentation/userspace-api/media/drivers/dw100.rst > >> +++ b/Documentation/userspace-api/media/drivers/dw100.rst > >> @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. > >> More details on the DW100 hardware operations can be found in > >> *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. > >> > >> +The Vivante DW100 m2m driver implements the following driver-specific control: > >> + > >> +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` > > > > (integer) -> (__u32 array) > > > > But should this be a __u32 array at all? Wouldn't a __u16 array make more sense? > > This is indeed debatable. But the array is describing vertices positions > on a 2D dimension space, and thus its size is always even. > More importantly, the array must follow the format imposed by the > hardware which expects __u16 pairs packed in a __u32. > Lastly, the lut (map) register size unit is __u32. > > Hence, IMHO, using __u32 might make more sense to highlight its hardware > dependency. Agreed. As mentioned in a reply to another patch, I think it would be useful to explain this a bit more clearly. Hans mentioned in the review of the driver itself that there was a bug as an image width of 16 bits results in a grid width of 2. I think that's correct (a width between 1 and 16 pixels results in a single grid cell horizontally, and thus two vertices, on the left and right side of the cell), but it would benefit from an explanation. A small ascii art diagram could help. > >> + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in > >> + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 > >> + dynamic array. The image is divided into many small 16x16 blocks. If the > >> + width of the image is not divisible by 16, the size of the rightmost block > >> + is the remainder. > > > > Isn't the same true for the height? > > Yes, will update accordingly. > > > The dewarping map only saves the vertex coordinates of the > > > >> + block. The dewarping grid map is comprised of vertex coordinates for x and y. > >> + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate > > > > As mentioned before, UQ12.4 is not necessarily a standard notation. 'unsigned 12.4 > > fixed point' is better, but you also need to specify exactly where the bits are > > stored inside the __u16. I.e.: 'the integer part is stored in the 12 most significant > > bits, and the fractional part is stored in the 4 least significant bits of the __u16.' > > > >> + address, with the Y coordinate in the upper bits and X in the lower bits. > > > > And with a __u16 array this becomes: 'The array contains pairs of X, Y coordinates.' > > Or something along those lines. > > > >> + > >> .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM > >> diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h > >> new file mode 100644 > >> index 000000000000..7fdcf2bf42e5 > >> --- /dev/null > >> +++ b/include/uapi/linux/dw100.h > >> @@ -0,0 +1,11 @@ > >> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > >> +/* Copyright 2022 NXP */ > >> + > >> +#ifndef __UAPI_DW100_H__ > >> +#define __UAPI_DW100_H__ > >> + > >> +#include <linux/v4l2-controls.h> > >> + > > > > Add a comment referring to the Documentation/userspace-api/media/drivers/dw100.rst > > documentation so users of this control know where to find the associated > > documentation. > > > >> +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) > >> + > >> +#endif
diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst index 4cd55c75628e..f6d684cadf26 100644 --- a/Documentation/userspace-api/media/drivers/dw100.rst +++ b/Documentation/userspace-api/media/drivers/dw100.rst @@ -20,4 +20,16 @@ match the expected size inherited from the destination image resolution. More details on the DW100 hardware operations can be found in *chapter 13.15 DeWarp* of IMX8MP_ reference manuel. +The Vivante DW100 m2m driver implements the following driver-specific control: + +``V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (integer)`` + Specifies to DW100 driver its dewarping map (aka LUT) blob as described in + *chapter 13.15.2.3 Dewarping Remap* of IMX8MP_ reference manual as an U32 + dynamic array. The image is divided into many small 16x16 blocks. If the + width of the image is not divisible by 16, the size of the rightmost block + is the remainder. The dewarping map only saves the vertex coordinates of the + block. The dewarping grid map is comprised of vertex coordinates for x and y. + Each x, y coordinate register uses 16 bits (UQ12.4) to record the coordinate + address, with the Y coordinate in the upper bits and X in the lower bits. + .. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM diff --git a/include/uapi/linux/dw100.h b/include/uapi/linux/dw100.h new file mode 100644 index 000000000000..7fdcf2bf42e5 --- /dev/null +++ b/include/uapi/linux/dw100.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ +/* Copyright 2022 NXP */ + +#ifndef __UAPI_DW100_H__ +#define __UAPI_DW100_H__ + +#include <linux/v4l2-controls.h> + +#define V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP (V4L2_CID_USER_DW100_BASE + 1) + +#endif
The DW100 driver gets the dewarping mapping as a binary blob from the userspace application through a custom control. The blob format is hardware specific so create a dedicated control for this purpose. Signed-off-by: Xavier Roumegue <xavier.roumegue@oss.nxp.com> --- Documentation/userspace-api/media/drivers/dw100.rst | 12 ++++++++++++ include/uapi/linux/dw100.h | 11 +++++++++++ 2 files changed, 23 insertions(+) create mode 100644 include/uapi/linux/dw100.h