Re: [RFC PATCH V3 3/3] platform: mtk-isp: Add Mediatek FD driver

[Jerry-ch Chen <Jerry-ch.Chen@mediatek.com>]

Hi Tomasz,

On Mon, 2019-12-02 at 18:48 +0900, Tomasz Figa wrote:
> On Sat, Nov 30, 2019 at 1:55 AM Jerry-ch Chen
> <Jerry-ch.Chen@mediatek.com> wrote:
> >
> > Hi Tomasz,
> >
> > On Wed, 2019-11-20 at 18:28 +0900, Tomasz Figa wrote:
> > > On Wed, Nov 20, 2019 at 5:11 PM Jerry-ch Chen
> > > <Jerry-ch.Chen@mediatek.com> wrote:
> > > >
> > > > Hi Tomasz,
> > > >
> > > > On Fri, 2019-10-25 at 11:52 +0800, Tomasz Figa wrote:
> > > > > On Tue, Oct 15, 2019 at 11:16:15AM +0800, Jerry-ch Chen wrote:
> > > > > > Hi Tomasz,
> > > > > >
> > > > > > On Fri, 2019-09-06 at 18:11 +0800, Jerry-ch Chen wrote:
> > > > > > > From: Jerry-ch Chen <jerry-ch.chen@mediatek.com>
> > > > > > >
> > > > > > > This patch adds the driver of Face Detection (FD) unit in
> > > > > > > Mediatek camera system, providing face detection function.
> > > > > > >
> > > > > > > The mtk-isp directory will contain drivers for multiple IP
> > > > > > > blocks found in Mediatek ISP system. It will include ISP Pass 1
> > > > > > > driver (CAM), sensor interface driver, DIP driver and face
> > > > > > > detection driver.
> > > > > > >
> > > > > > > Signed-off-by: Jerry-ch Chen <jerry-ch.chen@mediatek.com>
> > > > > > > ---
> > > > > > >  drivers/media/platform/Kconfig                |    2 +
> > > > > > >  drivers/media/platform/Makefile               |    2 +
> > > > > > >  drivers/media/platform/mtk-isp/fd/Kconfig     |   19 +
> > > > > > >  drivers/media/platform/mtk-isp/fd/Makefile    |    5 +
> > > > > > >  drivers/media/platform/mtk-isp/fd/mtk_fd.h    |  148 ++
> > > > > > >  drivers/media/platform/mtk-isp/fd/mtk_fd_40.c | 1219 +++++++++++++++++
> > > > > > >  include/uapi/linux/mtk-fd-v4l2-controls.h     |   69 +
> > > > > > >  include/uapi/linux/v4l2-controls.h            |    4 +
> > > > > > >  8 files changed, 1468 insertions(+)
> > > > > > >  create mode 100644 drivers/media/platform/mtk-isp/fd/Kconfig
> > > > > > >  create mode 100644 drivers/media/platform/mtk-isp/fd/Makefile
> > > > > > >  create mode 100644 drivers/media/platform/mtk-isp/fd/mtk_fd.h
> > > > > > >  create mode 100644 drivers/media/platform/mtk-isp/fd/mtk_fd_40.c
> > > > > > >  create mode 100644 include/uapi/linux/mtk-fd-v4l2-controls.h
> > > > > > >
> > > > >
> > > > > [snip]
[snip]
> > > > > [snip]
> > > > >
> > > > > > > +/* Set the face angle and directions to be detected */
> > > > > > > +#define V4L2_CID_MTK_FD_DETECT_POSE              (V4L2_CID_USER_MTK_FD_BASE + 1)
> > > > > > > +
> > > > > > > +/* Set image widths for an input image to be scaled down for face detection */
> > > > > > > +#define V4L2_CID_MTK_FD_SCALE_DOWN_IMG_WIDTH     (V4L2_CID_USER_MTK_FD_BASE + 2)
> > > > > > > +
> > > > > > > +/* Set image heights for an input image to be scaled down for face detection */
> > > > > > > +#define V4L2_CID_MTK_FD_SCALE_DOWN_IMG_HEIGHT    (V4L2_CID_USER_MTK_FD_BASE + 3)
> > > > > > > +
> > > > > > > +/* Set the length of scale down size array */
> > > > > > > +#define V4L2_CID_MTK_FD_SCALE_IMG_NUM            (V4L2_CID_USER_MTK_FD_BASE + 4)
> > > > > > > +
> > > > > > > +/* Set the detection speed, usually reducing accuracy. */
> > > > > > > +#define V4L2_CID_MTK_FD_DETECT_SPEED             (V4L2_CID_USER_MTK_FD_BASE + 5)
> > > > > > > +
> > > > > > > +/* Select the detection model or algorithm to be used. */
> > > > > > > +#define V4L2_CID_MTK_FD_DETECTION_MODEL          (V4L2_CID_USER_MTK_FD_BASE + 6)
> > > > > > > +
> > > > > > > +/* We reserve 16 controls for this driver. */
> > > > > > > +#define V4L2_CID_MTK_FD_MAX                      16
> > > > > > > +
> > > > > >
> > > > > > For these control IDs, I think the following should be remained as chip
> > > > > > specific controls.
> > > > > > V4L2_CID_MTK_FD_SCALE_DOWN_IMG_WIDTH,
> > > > > > V4L2_CID_MTK_FD_SCALE_DOWN_IMG_HEIGHT and V4L2_CID_MTK_FD_SCALE_IMG_NUM
> > > > > >
> > > > > > Hope there would be standardizing face detection api that cover the rest
> > > > > > controls: V4L2_CID_MTK_FD_DETECT_POSE, V4L2_CID_MTK_FD_DETECT_SPEED and
> > > > > > V4L2_CID_MTK_FD_DETECTION_MODEL
> > > > > >
> > > > > > Would you have any suggestions on how to propose the standard face
> > > > > > detection apis?
> > > > > >
> > > > >
> > > > > Given no follow up feedback from the community, I think we can keep them
> > > > > as driver-specific, but should make sure that they have some reasonable
> > > > > default values in case an application doesn't recognize them.
> > > > >
> > > > > Best regards,
> > > > > Tomasz
> > > > >
> > > > Should I keep the file "mtk-fd-v4l2-controls.h" which defines the
> > > > control ids under the folder "/include/uapi/linux"?
> > >
> > > We should define the CID base for the FD driver in v4l2-controls.h,
> > > but the controls themselves should be only defined inside the driver.
> > >
> > > For example:
> > > https://elixir.bootlin.com/linux/v5.4-rc8/source/include/uapi/linux/v4l2-controls.h#L178
> > > https://elixir.bootlin.com/linux/v5.4-rc8/source/drivers/media/i2c/adv7180.c#L181
> > >
> > > Best regards,
> > > Tomasz
> >
> > Appreciate for providing the example,
> > Would it be fine for me to put the private CID in the mtk_fd.h(which is
> > similar to before...) or follow the example to define inside
> > mtk_fd_40.c??
> >
> > The next version is almost ready, maybe I can send it when I ready in a
> > few days?
> 
> Since mtk_fd_40.c is the only place the definitions from mtk_fd.h are
> used, I'd suggest just moving all the contents to the .c file.
> 
> Best regards,
> Tomasz
Done,

Thanks and best regards,
Jerry