On Wed, Jun 05, 2024 at 06:54:21PM +0200, Jacopo Mondi wrote: > Add a new format definition for the RkISP1 extensible parameters > format and document it. > > Document the usage of the new format in the rkisp1 admin guide. > > Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx> > --- > Documentation/admin-guide/media/rkisp1.rst | 11 +++- > .../media/v4l/metafmt-rkisp1.rst | 62 ++++++++++++++++--- > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > include/uapi/linux/videodev2.h | 1 + > 4 files changed, 64 insertions(+), 11 deletions(-) > > diff --git a/Documentation/admin-guide/media/rkisp1.rst b/Documentation/admin-guide/media/rkisp1.rst > index 6f14d9561fa5..934c25e191df 100644 > --- a/Documentation/admin-guide/media/rkisp1.rst > +++ b/Documentation/admin-guide/media/rkisp1.rst > @@ -114,11 +114,18 @@ to be applied to the hardware during a video stream, allowing userspace > to dynamically modify values such as black level, cross talk corrections > and others. > > -The buffer format is defined by struct :c:type:`rkisp1_params_cfg`, and > -userspace should set > +The ISP driver supports two different parameters configuration methods, the > +`fixed parameters format` or the `extensible parameters format`. > + > +When using the `fixed parameters` method the buffer format is defined by struct > +:c:type:`rkisp1_params_cfg`, and userspace set > :ref:`V4L2_META_FMT_RK_ISP1_PARAMS <v4l2-meta-fmt-rk-isp1-params>` as the > dataformat. > > +When using the fixed parameters method the buffer format is defined by struct s/fixed/extensible/ ? > +:c:type:`rkisp1_ext_params_cfg`, and userspace set > +:ref:`V4L2_META_FMT_RK_ISP1_EXT_PARAMS <v4l2-meta-fmt-rk-isp1-ext-params>` as > +the dataformat. > > Capturing Video Frames Example > ============================== > diff --git a/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst b/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst > index fa04f00bcd2e..6ff776d071a3 100644 > --- a/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst > +++ b/Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst > @@ -1,28 +1,72 @@ > .. SPDX-License-Identifier: GPL-2.0 > > -.. _v4l2-meta-fmt-rk-isp1-params: > - > .. _v4l2-meta-fmt-rk-isp1-stat-3a: > > -***************************************************************************** > -V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s') > -***************************************************************************** > +************************************************************************************************************************ > +V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s'), V4L2_META_FMT_RK_ISP1_EXT_PARAMS ('rk1e') > +************************************************************************************************************************ > > +======================== > Configuration parameters > ======================== > > -The configuration parameters are passed to the > +The configuration of the RkISP1 ISP is performed by userspace by providing > +parameters for the ISP to the driver using the :c:type:`v4l2_meta_format` > +interface. > + > +There are currently two methods that allow to configure the ISP, the `fixed > +parameters` configuration format and the `extensible parameters` configuration > +format. > + > +.. _v4l2-meta-fmt-rk-isp1-params: > + > +Fixed parameters configuration format > +===================================== > + > +When using the fixed configuration format, parameters are passed to the > :ref:`rkisp1_params <rkisp1_params>` metadata output video node, using > -the :c:type:`v4l2_meta_format` interface. The buffer contains > -a single instance of the C structure :c:type:`rkisp1_params_cfg` defined in > -``rkisp1-config.h``. So the structure can be obtained from the buffer by: > +the `V4L2_META_FMT_RK_ISP1_PARAMS` meta pixel format. > + > +The buffer contains a single instance of the C structure > +:c:type:`rkisp1_params_cfg` defined in ``rkisp1-config.h``. So the structure can > +be obtained from the buffer by: > > .. code-block:: c > > struct rkisp1_params_cfg *params = (struct rkisp1_params_cfg*) buffer; > > +As the members of :c:type:`rkisp1_params_cfg` are defined in the > +``rkisp1-config.h`` header, the structure layout is immutable and cannot be > +extended further. For this reason the fixed configuration format only allows the > +configuration of the ISP blocks supported at the time when the structure had > +been defined in the header file, as introducing new parameters or modifying the > +existing ones would change the buffer layout and cause breakages in existing > +applications. > + > +.. _v4l2-meta-fmt-rk-isp1-ext-params: > + > +Extensible parameters configuration format > +========================================== > + > +When using the extensible configuration format, parameters are passed to the > +:ref:`rkisp1_params <rkisp1_params>` metadata output video node, using > +the `V4L2_META_FMT_RK_ISP1_EXT_PARAMS` meta pixel format. > + > +The buffer contains a single instance of the C structure > +:c:type:`rkisp1_ext_params_cfg` defined in ``rkisp1-config.h``. The > +:c:type:`rkisp1_ext_params_cfg` structure is designed to allow userspace to > +populate the data buffer with only the configuration data for the ISP block it > +intends to configure. The extensible parameters format design allows to define s/allows to define/allows defining/ > +new block types and new configuration parameters and defines a versioning scheme s/parameters/parameters,/ Reviewed-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx> > +so that it can be extended and versioned without breaking compatibility with > +existing applications. > + > +For these reasons, this configuration method if preferred over the `fixed > +parameters` format alternative. > + > .. rkisp1_stat_buffer > > +=========================== > 3A and histogram statistics > =========================== > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index 4c76d17b4629..aefdc1efd24b 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1456,6 +1456,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt) > case V4L2_META_FMT_VIVID: descr = "Vivid Metadata"; break; > case V4L2_META_FMT_RK_ISP1_PARAMS: descr = "Rockchip ISP1 3A Parameters"; break; > case V4L2_META_FMT_RK_ISP1_STAT_3A: descr = "Rockchip ISP1 3A Statistics"; break; > + case V4L2_META_FMT_RK_ISP1_EXT_PARAMS: descr = "Rockchip ISP1 Ext 3A Params"; break; > case V4L2_PIX_FMT_NV12_8L128: descr = "NV12 (8x128 Linear)"; break; > case V4L2_PIX_FMT_NV12M_8L128: descr = "NV12M (8x128 Linear)"; break; > case V4L2_PIX_FMT_NV12_10BE_8L128: descr = "10-bit NV12 (8x128 Linear, BE)"; break; > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index fe6b67e83751..7c2a303c6f59 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -840,6 +840,7 @@ struct v4l2_pix_format { > /* Vendor specific - used for RK_ISP1 camera sub-system */ > #define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */ > #define V4L2_META_FMT_RK_ISP1_STAT_3A v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */ > +#define V4L2_META_FMT_RK_ISP1_EXT_PARAMS v4l2_fourcc('R', 'K', '1', 'E') /* Rockchip ISP1 3a Extensible Parameters */ > > #ifdef __KERNEL__ > /* > -- > 2.45.1 >