Hi Dongchun,
On Mon, Jun 15, 2020 at 7:57 AM Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx> wrote:
>
> Hi Tomasz,
>
> On Fri, 2020-06-12 at 20:39 +0200, Tomasz Figa wrote:
> > On Fri, Jun 12, 2020 at 12:49 PM Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx> wrote:
> > >
> > > Hi Tomasz,
> > >
> > > On Wed, 2020-06-10 at 19:44 +0000, Tomasz Figa wrote:
> > > > Hi Dongchun,
> > > >
> > > > On Sat, May 23, 2020 at 04:41:03PM +0800, Dongchun Zhu wrote:
> > > > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > > > >
> > > > > Signed-off-by: Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx>
> > > > > ---
> > > > > MAINTAINERS | 1 +
> > > > > drivers/media/i2c/Kconfig | 13 +
> > > > > drivers/media/i2c/Makefile | 1 +
> > > > > drivers/media/i2c/ov02a10.c | 1025 +++++++++++++++++++++++++++++++++++++++++++
> > > > > 4 files changed, 1040 insertions(+)
> > > > > create mode 100644 drivers/media/i2c/ov02a10.c
> > > > >
> > > >
> > > > Thank you for the patch. Please see my comments inline.
> > > >
> > > > [snip]
> > > > > diff --git a/drivers/media/i2c/ov02a10.c b/drivers/media/i2c/ov02a10.c
> > > > > new file mode 100644
> > > > > index 0000000..160a0b5
> > > > > --- /dev/null
> > > > > +++ b/drivers/media/i2c/ov02a10.c
> > > > [snip]
> > > > > +static const char * const ov02a10_test_pattern_menu[] = {
> > > > > + "Disabled",
> > > > > + "Color Bar",
> > > >
> > > > nit: We should normalize this to one of the standard names. What is the
> > > > pattern on this sensor? Is it perhaps "Eight Vertical Colour Bars"?
> > > >
> > >
> > > Yes. It is one kind of 'Eight Vertical Colour Bars'.
> > > This pattern is called as 'MIPI color bar' per the datasheet.
> > > Can we here use 'Vertical Color Bar' or 'MIPI Color Bar'?
> > >
> >
> > We should try to stick to the names as exposed by existing drivers.
> > There was an attempt to unify the naming of some Sony sensors some
> > time ago [1]. Perhaps one of the names there matches the pattern of
> > this sensor?
> >
> > [1] https://patchwork.kernel.org/patch/10711777/
> >
>
> Sounds great.
> It is one good idea to summarize test patterns from various sensors.
> But one question plaguing me is that it seems even for the same "Eight
> Vertical Colour Bars", different sensors may have different RGB color
> map.
>
> Moreover, definition standards of color bar style may differ among
> different sensor chip vendors.
> For instance, Sony often uses "Solid Color", "Color Bars With Fade to
> Grey", "PN9" to abstract test pattern output type; while OmniVision
> adopts color bar type 1, 2, 3, 4 or "MIPI Color Bar", "ISP Color Bar"
> instead.
The test patterns are commonly very similar, just different vendors
call them with different names. There is actually a specification
called MIPI CCS [1], which standardizes many aspects of sensor
programming, including test patterns. Most of the sensors don't really
follow the entire specification yet, but often some aspects happen to
match.
In the copy of the specification that I have, the test patterns are
described in section 10 (Test modes), page 203, with pictures on
following pages. Perhaps we could standardize the names based on that,
when the pattern matches?
Sakari, what do you think?
[1] http://resources.mipi.org/camera-command-set-v1-1-download
Best regards,
Tomasz
