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Date:   Wed, 9 Mar 2022 16:57:52 +0100
From:   Jacopo Mondi <jacopo@jmondi.org>
To:     Eugen.Hristev@microchip.com
Cc:     linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Claudiu.Beznea@microchip.com, hverkuil-cisco@xs4all.nl,
        Nicolas.Ferre@microchip.com
Subject: Re: [PATCH v7 04/13] media: atmel: atmel-isc: implement media
 controller
Message-ID: <20220309155752.p2gjye7gnldw2th4@uno.localdomain>
References: <20220307120423.2427631-1-eugen.hristev@microchip.com>
 <20220307120423.2427631-5-eugen.hristev@microchip.com>
 <20220309152252.oz25pldorpred3cy@uno.localdomain>
 <4be270ed-608b-eac5-da57-3ca61f505140@microchip.com>
MIME-Version: 1.0
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In-Reply-To: <4be270ed-608b-eac5-da57-3ca61f505140@microchip.com>
Precedence: bulk

Hi Eugen

On Wed, Mar 09, 2022 at 03:39:26PM +0000, Eugen.Hristev@microchip.com wrote:
> On 3/9/22 5:22 PM, Jacopo Mondi wrote:
> > Hi Eugen,
> >     sorry one more comment
> >
> > On Mon, Mar 07, 2022 at 02:04:14PM +0200, Eugen Hristev wrote:
> >> Implement the support for media-controller.
> >> This means that the capabilities of the driver have changed and now
> >> it also advertises the IO_MC .
> >> The driver will register its media device, and add the video entity to this
> >> media device. The subdevices are registered to the same media device.
> >> The ISC will have a base entity which is auto-detected as atmel_isc_base.
> >> It will also register a subdevice that allows cropping of the incoming frame
> >> to the maximum frame size supported by the ISC.
> >> The ISC will create a link between the subdevice that is asynchronously
> >> registered and the atmel_isc_scaler entity.
> >> Then, the atmel_isc_scaler and atmel_isc_base are connected through another
> >> link.
> >>
> >> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> >> ---
> >> Changes in v7:
> >> - use maximum isc frame size as bounds always
> >>
> >> Changes in v6:
> >> - reworked a bit as suggested by Jacopo
> >> - add try crops
> >>
> >> Changes in v5:
> >> - reworked s_fmt to pass the same format from sink to source
> >> - simplified enum_mbus_code
> >> - separated tgt and bounds to report correctly in g_sel
> >>
> >> Changes in v4:
> >> As suggested by Jacopo:
> >> - renamed atmel_isc_mc to atmel_isc_scaler.c
> >> - moved init_mc/clean_mc to isc_base file
> >>
> >> Changes in v2:
> >> - implement try formats
> >>
> >>
> >>   drivers/media/platform/atmel/Makefile         |   2 +-
> >>   drivers/media/platform/atmel/atmel-isc-base.c |  75 ++++-
> >>   .../media/platform/atmel/atmel-isc-scaler.c   | 271 ++++++++++++++++++
> >>   drivers/media/platform/atmel/atmel-isc.h      |  37 +++
> >>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  14 +-
> >>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  12 +-
> >>   6 files changed, 403 insertions(+), 8 deletions(-)
> >>   create mode 100644 drivers/media/platform/atmel/atmel-isc-scaler.c
> >>
> >> diff --git a/drivers/media/platform/atmel/Makefile b/drivers/media/platform/atmel/Makefile
> >> index 794e8f739287..f02d03df89d6 100644
> >> --- a/drivers/media/platform/atmel/Makefile
> >> +++ b/drivers/media/platform/atmel/Makefile
> >> @@ -1,7 +1,7 @@
> >>   # SPDX-License-Identifier: GPL-2.0-only
> >>   atmel-isc-objs = atmel-sama5d2-isc.o
> >>   atmel-xisc-objs = atmel-sama7g5-isc.o
> >> -atmel-isc-common-objs = atmel-isc-base.o atmel-isc-clk.o
> >> +atmel-isc-common-objs = atmel-isc-base.o atmel-isc-clk.o atmel-isc-scaler.o
> >>
> >>   obj-$(CONFIG_VIDEO_ATMEL_ISI) += atmel-isi.o
> >>   obj-$(CONFIG_VIDEO_ATMEL_ISC_BASE) += atmel-isc-common.o
> >> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> >> index 67b4a2323fed..448bf281c61a 100644
> >> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> >> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> >> @@ -1712,6 +1712,7 @@ static int isc_async_bound(struct v4l2_async_notifier *notifier,
> >>                                              struct isc_device, v4l2_dev);
> >>        struct isc_subdev_entity *subdev_entity =
> >>                container_of(notifier, struct isc_subdev_entity, notifier);
> >> +     int pad;
> >>
> >>        if (video_is_registered(&isc->video_dev)) {
> >>                v4l2_err(&isc->v4l2_dev, "only supports one sub-device.\n");
> >> @@ -1720,6 +1721,16 @@ static int isc_async_bound(struct v4l2_async_notifier *notifier,
> >>
> >>        subdev_entity->sd = subdev;
> >>
> >> +     pad = media_entity_get_fwnode_pad(&subdev->entity, asd->match.fwnode,
> >> +                                       MEDIA_PAD_FL_SOURCE);
> >> +     if (pad < 0) {
> >> +             v4l2_err(&isc->v4l2_dev, "failed to find pad for %s\n",
> >> +                      subdev->name);
> >> +             return pad;
> >> +     }
> >> +
> >> +     isc->remote_pad = pad;
> >> +
> >>        return 0;
> >>   }
> >>
> >> @@ -1734,8 +1745,8 @@ static void isc_async_unbind(struct v4l2_async_notifier *notifier,
> >>        v4l2_ctrl_handler_free(&isc->ctrls.handler);
> >>   }
> >>
> >> -static struct isc_format *find_format_by_code(struct isc_device *isc,
> >> -                                           unsigned int code, int *index)
> >> +struct isc_format *isc_find_format_by_code(struct isc_device *isc,
> >> +                                        unsigned int code, int *index)
> >>   {
> >>        struct isc_format *fmt = &isc->formats_list[0];
> >>        unsigned int i;
> >> @@ -1751,6 +1762,7 @@ static struct isc_format *find_format_by_code(struct isc_device *isc,
> >>
> >>        return NULL;
> >>   }
> >> +EXPORT_SYMBOL_GPL(isc_find_format_by_code);
> >>
> >>   static int isc_formats_init(struct isc_device *isc)
> >>   {
> >> @@ -1767,7 +1779,7 @@ static int isc_formats_init(struct isc_device *isc)
> >>               NULL, &mbus_code)) {
> >>                mbus_code.index++;
> >>
> >> -             fmt = find_format_by_code(isc, mbus_code.code, &i);
> >> +             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
> >>                if (!fmt) {
> >>                        v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
> >>                                  mbus_code.code);
> >> @@ -1893,7 +1905,8 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
> >>        vdev->queue             = q;
> >>        vdev->lock              = &isc->lock;
> >>        vdev->ctrl_handler      = &isc->ctrls.handler;
> >> -     vdev->device_caps       = V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_CAPTURE;
> >> +     vdev->device_caps       = V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_CAPTURE |
> >> +                               V4L2_CAP_IO_MC;
> >>        video_set_drvdata(vdev, isc);
> >>
> >>        ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> >> @@ -1903,8 +1916,19 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
> >>                goto isc_async_complete_err;
> >>        }
> >>
> >> +     ret = isc_scaler_link(isc);
> >> +     if (ret < 0)
> >> +             goto isc_async_complete_unregister_device;
> >> +
> >> +     ret = media_device_register(&isc->mdev);
> >> +     if (ret < 0)
> >> +             goto isc_async_complete_unregister_device;
> >> +
> >>        return 0;
> >>
> >> +isc_async_complete_unregister_device:
> >> +     video_unregister_device(vdev);
> >> +
> >>   isc_async_complete_err:
> >>        mutex_destroy(&isc->lock);
> >>        return ret;
> >> @@ -1971,6 +1995,49 @@ int isc_pipeline_init(struct isc_device *isc)
> >>   }
> >>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
> >>
> >> +int isc_mc_init(struct isc_device *isc, u32 ver)
> >> +{
> >> +     const struct of_device_id *match;
> >> +     int ret;
> >> +
> >> +     isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
> >> +     isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
> >> +     isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> >> +
> >> +     ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
> >> +                                  isc->pads);
> >> +     if (ret < 0) {
> >> +             dev_err(isc->dev, "media entity init failed\n");
> >> +             return ret;
> >> +     }
> >> +
> >> +     isc->mdev.dev = isc->dev;
> >> +
> >> +     match = of_match_node(isc->dev->driver->of_match_table,
> >> +                           isc->dev->of_node);
> >> +
> >> +     strscpy(isc->mdev.driver_name, KBUILD_MODNAME,
> >> +             sizeof(isc->mdev.driver_name));
> >> +     strscpy(isc->mdev.model, match->compatible, sizeof(isc->mdev.model));
> >> +     snprintf(isc->mdev.bus_info, sizeof(isc->mdev.bus_info), "platform:%s",
> >> +              isc->v4l2_dev.name);
> >> +     isc->mdev.hw_revision = ver;
> >> +
> >> +     media_device_init(&isc->mdev);
> >> +
> >> +     isc->v4l2_dev.mdev = &isc->mdev;
> >> +
> >> +     return isc_scaler_init(isc);
> >> +}
> >> +EXPORT_SYMBOL_GPL(isc_mc_init);
> >> +
> >> +void isc_mc_cleanup(struct isc_device *isc)
> >> +{
> >> +     media_entity_cleanup(&isc->video_dev.entity);
> >> +     media_device_cleanup(&isc->mdev);
> >> +}
> >> +EXPORT_SYMBOL_GPL(isc_mc_cleanup);
> >> +
> >>   /* regmap configuration */
> >>   #define ATMEL_ISC_REG_MAX    0xd5c
> >>   const struct regmap_config isc_regmap_config = {
> >> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
> >> new file mode 100644
> >> index 000000000000..d3dd131fdae0
> >> --- /dev/null
> >> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
> >> @@ -0,0 +1,271 @@
> >> +// SPDX-License-Identifier: GPL-2.0-only
> >> +/*
> >> + * Microchip Image Sensor Controller (ISC) Scaler entity support
> >> + *
> >> + * Copyright (C) 2022 Microchip Technology, Inc.
> >> + *
> >> + * Author: Eugen Hristev <eugen.hristev@microchip.com>
> >> + *
> >> + */
> >> +
> >> +#include <media/media-device.h>
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-device.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +#include "atmel-isc-regs.h"
> >> +#include "atmel-isc.h"
> >> +
> >> +static void isc_scaler_prepare_fmt(struct v4l2_mbus_framefmt *framefmt)
> >> +{
> >> +     framefmt->colorspace = V4L2_COLORSPACE_SRGB;
> >> +     framefmt->field = V4L2_FIELD_NONE;
> >> +     framefmt->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> >> +     framefmt->quantization = V4L2_QUANTIZATION_DEFAULT;
> >> +     framefmt->xfer_func = V4L2_XFER_FUNC_DEFAULT;
> >> +};
> >> +
> >> +static int isc_scaler_get_fmt(struct v4l2_subdev *sd,
> >> +                           struct v4l2_subdev_state *sd_state,
> >> +                           struct v4l2_subdev_format *format)
> >> +{
> >> +     struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
> >> +     struct v4l2_mbus_framefmt *v4l2_try_fmt;
> >> +
> >> +     if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> >> +             v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
> >> +                                                       format->pad);
> >> +             format->format = *v4l2_try_fmt;
> >> +
> >> +             return 0;
> >> +     }
> >> +
> >> +     format->format = isc->scaler_format[format->pad];
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int isc_scaler_set_fmt(struct v4l2_subdev *sd,
> >> +                           struct v4l2_subdev_state *sd_state,
> >> +                           struct v4l2_subdev_format *req_fmt)
> >> +{
> >> +     struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
> >> +     struct v4l2_mbus_framefmt *v4l2_try_fmt;
> >> +     struct isc_format *fmt;
> >> +     unsigned int i;
> >> +
> >> +     /* Source format is fixed, we cannot change it */
> >> +     if (req_fmt->pad == ISC_SCALER_PAD_SOURCE) {
> >> +             req_fmt->format = isc->scaler_format[ISC_SCALER_PAD_SOURCE];
> >> +             return 0;
> >> +     }
> >> +
> >> +     /* There is no limit on the frame size on the sink pad */
> >> +     v4l_bound_align_image(&req_fmt->format.width, 16, UINT_MAX, 0,
> >> +                           &req_fmt->format.height, 16, UINT_MAX, 0, 0);
> >> +
> >> +     isc_scaler_prepare_fmt(&req_fmt->format);
> >> +
> >> +     fmt = isc_find_format_by_code(isc, req_fmt->format.code, &i);
> >> +
> >> +     if (!fmt)
> >> +             fmt = &isc->formats_list[0];
> >> +
> >> +     req_fmt->format.code = fmt->mbus_code;
> >> +
> >> +     if (req_fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> >> +             v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
> >> +                                                       req_fmt->pad);
> >> +             *v4l2_try_fmt = req_fmt->format;
> >> +             /* Trying on the sink pad makes the source pad change too */
> >> +             v4l2_try_fmt = v4l2_subdev_get_try_format(sd, sd_state,
> >> +                                                       ISC_SCALER_PAD_SOURCE);
> >> +             *v4l2_try_fmt = req_fmt->format;
> >> +
> >> +             v4l_bound_align_image(&v4l2_try_fmt->width,
> >> +                                   16, isc->max_width, 0,
> >> +                                   &v4l2_try_fmt->height,
> >> +                                   16, isc->max_height, 0, 0);
> >> +             /* if we are just trying, we are done */
> >> +             return 0;
> >> +     }
> >> +
> >> +     isc->scaler_format[ISC_SCALER_PAD_SINK] = req_fmt->format;
> >> +
> >> +     /* The source pad is the same as the sink, but we have to crop it */
> >> +     isc->scaler_format[ISC_SCALER_PAD_SOURCE] =
> >> +             isc->scaler_format[ISC_SCALER_PAD_SINK];
> >> +     v4l_bound_align_image
> >> +             (&isc->scaler_format[ISC_SCALER_PAD_SOURCE].width, 16,
> >> +              isc->max_width, 0,
> >> +              &isc->scaler_format[ISC_SCALER_PAD_SOURCE].height, 16,
> >> +              isc->max_height, 0, 0);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int isc_scaler_enum_mbus_code(struct v4l2_subdev *sd,
> >> +                                  struct v4l2_subdev_state *sd_state,
> >> +                                  struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +     struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
> >> +
> >> +     /*
> >> +      * All formats supported by the ISC are supported by the scaler.
> >> +      * Advertise the formats which the ISC can take as input, as the scaler
> >> +      * entity cropping is part of the PFE module (parallel front end)
> >> +      */
> >> +     if (code->index < isc->formats_list_size) {
> >> +             code->code = isc->formats_list[code->index].mbus_code;
> >> +             return 0;
> >> +     }
> >> +
> >> +     return -EINVAL;
> >> +}
> >> +
> >> +static int isc_scaler_g_sel(struct v4l2_subdev *sd,
> >> +                         struct v4l2_subdev_state *sd_state,
> >> +                         struct v4l2_subdev_selection *sel)
> >> +{
> >> +     struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
> >> +
> >> +     if (sel->pad == ISC_SCALER_PAD_SOURCE)
> >> +             return -EINVAL;
> >> +
> >> +     if (sel->target == V4L2_SEL_TGT_CROP_BOUNDS) {
> >> +             /* bounds are the maximum rectangle which ISC can take */
> >> +             sel->r.height = isc->max_height;
> >> +             sel->r.width = isc->max_width;
> >> +             sel->r.left = 0;
> >> +             sel->r.top = 0;
> >
> > Sorry in my previous reply I suggested to fix _BOUND to the max size, but
> > what happens if the image format on the sink pad is smaller than max
> > size ? As _BOUNDS should contains all valid crop rectangles and you
> > don't have a set_selection which might change the CROP rectangle , I
> > think for your case BOUND==CROP, otherwise you could end up with a
> > BOUND rectangle larger than the input frame.
> >
> > I would do something along the lines of:
> >
> >          switch (sel->target) {
> >          case V4L2_SEL_TGT_CROP_BOUNDS:
> >                  /* Fall-through */
> >          case V4L2_SEL_TGT_CROP:
> >                  /*
> >                   * crop is done to the output format,
> >                   * limited by ISC maximum size
> >                   */
> >                  sel->r.height = isc->scaler_format[ISC_SCALER_PAD_SOURCE].height;
> >                  sel->r.width = isc->scaler_format[ISC_SCALER_PAD_SOURCE].width;
> >                  sel->r.left = 0;
> >                  sel->r.top = 0;
> >
> >                  return 0;
> >         default:
> >                  return -EINVAL;
> >
>
> Hi Jacopo,
>
> Actually this is now much similar with what I initially had , in v4 of
> the patch :
>
> =====
>
> +static int isc_scaler_g_sel(struct v4l2_subdev *sd,
> +                           struct v4l2_subdev_state *sd_state,
> +                           struct v4l2_subdev_selection *sel)
> +{
> +       struct isc_device *isc = container_of(sd, struct isc_device,
> scaler_sd);
> +
> +       if (sel->pad == ISC_SCALER_PAD_SOURCE)
> +               return -EINVAL;
> +
> +       if (sel->target != V4L2_SEL_TGT_CROP_BOUNDS &&
> +           sel->target != V4L2_SEL_TGT_CROP)
> +               return -EINVAL;
> +
> +       sel->r.height = isc->max_height;
> +       sel->r.width = isc->max_width;
> +
> +       sel->r.left = 0;
> +       sel->r.top = 0;
> +
> +       return 0;
> +}
> =====

More or less, as in this case you had both rectangles set to max_size.
But you're right you had BOUND == CROP. Sorry about this.

>
> In there I was setting height and width to maximum isc frame size, but I
> will change it to source pad format size.
> Do you like it like this ?
>
> =====
>
>         if (sel->target != V4L2_SEL_TGT_CROP_BOUNDS &&
>             sel->target != V4L2_SEL_TGT_CROP)
>                 return -EINVAL;
>
>         sel->r.height = isc->scaler_format[ISC_SCALER_PAD_SOURCE].height;
>         sel->r.width = isc->scaler_format[ISC_SCALER_PAD_SOURCE].width;
>
>         sel->r.left = 0;
>         sel->r.top = 0;
> =====

Thanks this match my understanding.
Please add my tag to v8 and sorry again for the back&forth.

Cheers
   j
>
> Eugen
>
> >
> > I'm sorry if this will require you a new version, I missed that in v6.
> > Please let me know if you agree with my proposal.
> >
> > Feel free to add the tag in v8
> > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> >
> > Thanks
> >     j
> >
> >> +     } else if (sel->target == V4L2_SEL_TGT_CROP) {
> >> +             /*
> >> +              * crop is done to the output format,
> >> +              * limited by ISC maximum size
> >> +              */
> >> +             sel->r.height = isc->scaler_format[ISC_SCALER_PAD_SOURCE].height;
> >> +             sel->r.width = isc->scaler_format[ISC_SCALER_PAD_SOURCE].width;
> >> +             sel->r.left = 0;
> >> +             sel->r.top = 0;
> >> +     } else {
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int isc_scaler_init_cfg(struct v4l2_subdev *sd,
> >> +                            struct v4l2_subdev_state *sd_state)
> >> +{
> >> +     struct v4l2_mbus_framefmt *v4l2_try_fmt =
> >> +             v4l2_subdev_get_try_format(sd, sd_state, 0);
> >> +     struct v4l2_rect *try_crop;
> >> +     struct isc_device *isc = container_of(sd, struct isc_device, scaler_sd);
> >> +
> >> +     *v4l2_try_fmt = isc->scaler_format[ISC_SCALER_PAD_SOURCE];
> >> +
> >> +     try_crop = v4l2_subdev_get_try_crop(sd, sd_state, 0);
> >> +
> >> +     try_crop->top = 0;
> >> +     try_crop->left = 0;
> >> +     try_crop->width = v4l2_try_fmt->width;
> >> +     try_crop->height = v4l2_try_fmt->height;
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
> >> +     .enum_mbus_code = isc_scaler_enum_mbus_code,
> >> +     .set_fmt = isc_scaler_set_fmt,
> >> +     .get_fmt = isc_scaler_get_fmt,
> >> +     .get_selection = isc_scaler_g_sel,
> >> +     .init_cfg = isc_scaler_init_cfg,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
> >> +     .pad = &isc_scaler_pad_ops,
> >> +};
> >> +
> >> +int isc_scaler_init(struct isc_device *isc)
> >> +{
> >> +     int ret;
> >> +
> >> +     v4l2_subdev_init(&isc->scaler_sd, &xisc_scaler_subdev_ops);
> >> +
> >> +     isc->scaler_sd.owner = THIS_MODULE;
> >> +     isc->scaler_sd.dev = isc->dev;
> >> +     snprintf(isc->scaler_sd.name, sizeof(isc->scaler_sd.name),
> >> +              "atmel_isc_scaler");
> >> +
> >> +     isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >> +     isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
> >> +     isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> >> +     isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> >> +
> >> +     isc_scaler_prepare_fmt(&isc->scaler_format[ISC_SCALER_PAD_SOURCE]);
> >> +     isc->scaler_format[ISC_SCALER_PAD_SOURCE].height = isc->max_height;
> >> +     isc->scaler_format[ISC_SCALER_PAD_SOURCE].width = isc->max_width;
> >> +     isc->scaler_format[ISC_SCALER_PAD_SOURCE].code =
> >> +              isc->formats_list[0].mbus_code;
> >> +
> >> +     isc->scaler_format[ISC_SCALER_PAD_SINK] =
> >> +              isc->scaler_format[ISC_SCALER_PAD_SOURCE];
> >> +
> >> +     ret = media_entity_pads_init(&isc->scaler_sd.entity,
> >> +                                  ISC_SCALER_PADS_NUM,
> >> +                                  isc->scaler_pads);
> >> +     if (ret < 0) {
> >> +             dev_err(isc->dev, "scaler sd media entity init failed\n");
> >> +             return ret;
> >> +     }
> >> +
> >> +     ret = v4l2_device_register_subdev(&isc->v4l2_dev, &isc->scaler_sd);
> >> +     if (ret < 0) {
> >> +             dev_err(isc->dev, "scaler sd failed to register subdev\n");
> >> +             return ret;
> >> +     }
> >> +
> >> +     return ret;
> >> +}
> >> +EXPORT_SYMBOL_GPL(isc_scaler_init);
> >> +
> >> +int isc_scaler_link(struct isc_device *isc)
> >> +{
> >> +     int ret;
> >> +
> >> +     ret = media_create_pad_link(&isc->current_subdev->sd->entity,
> >> +                                 isc->remote_pad, &isc->scaler_sd.entity,
> >> +                                 ISC_SCALER_PAD_SINK,
> >> +                                 MEDIA_LNK_FL_ENABLED |
> >> +                                 MEDIA_LNK_FL_IMMUTABLE);
> >> +
> >> +     if (ret < 0) {
> >> +             dev_err(isc->dev, "Failed to create pad link: %s to %s\n",
> >> +                     isc->current_subdev->sd->entity.name,
> >> +                     isc->scaler_sd.entity.name);
> >> +             return ret;
> >> +     }
> >> +
> >> +     dev_dbg(isc->dev, "link with %s pad: %d\n",
> >> +             isc->current_subdev->sd->name, isc->remote_pad);
> >> +
> >> +     ret = media_create_pad_link(&isc->scaler_sd.entity,
> >> +                                 ISC_SCALER_PAD_SOURCE,
> >> +                                 &isc->video_dev.entity, ISC_PAD_SINK,
> >> +                                 MEDIA_LNK_FL_ENABLED |
> >> +                                 MEDIA_LNK_FL_IMMUTABLE);
> >> +
> >> +     if (ret < 0) {
> >> +             dev_err(isc->dev, "Failed to create pad link: %s to %s\n",
> >> +                     isc->scaler_sd.entity.name,
> >> +                     isc->video_dev.entity.name);
> >> +             return ret;
> >> +     }
> >> +
> >> +     dev_dbg(isc->dev, "link with %s pad: %d\n", isc->scaler_sd.name,
> >> +             ISC_SCALER_PAD_SOURCE);
> >> +
> >> +     return ret;
> >> +}
> >> +EXPORT_SYMBOL_GPL(isc_scaler_link);
> >> +
> >> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
> >> index f9ad7ec6bd13..9cc69c3ae26d 100644
> >> --- a/drivers/media/platform/atmel/atmel-isc.h
> >> +++ b/drivers/media/platform/atmel/atmel-isc.h
> >> @@ -183,6 +183,17 @@ struct isc_reg_offsets {
> >>        u32 his_entry;
> >>   };
> >>
> >> +enum isc_mc_pads {
> >> +     ISC_PAD_SINK    = 0,
> >> +     ISC_PADS_NUM    = 1,
> >> +};
> >> +
> >> +enum isc_scaler_pads {
> >> +     ISC_SCALER_PAD_SINK     = 0,
> >> +     ISC_SCALER_PAD_SOURCE   = 1,
> >> +     ISC_SCALER_PADS_NUM     = 2,
> >> +};
> >> +
> >>   /*
> >>    * struct isc_device - ISC device driver data/config struct
> >>    * @regmap:          Register map
> >> @@ -258,6 +269,12 @@ struct isc_reg_offsets {
> >>    *                   be used as an input to the controller
> >>    * @controller_formats_size: size of controller_formats array
> >>    * @formats_list_size:       size of formats_list array
> >> + * @pads:            media controller pads for isc video entity
> >> + * @mdev:            media device that is registered by the isc
> >> + * @remote_pad:              remote pad on the connected subdevice
> >> + * @scaler_sd:               subdevice for the scaler that isc registers
> >> + * @scaler_pads:     media controller pads for the scaler subdevice
> >> + * @scaler_format:   current format for the scaler subdevice
> >>    */
> >>   struct isc_device {
> >>        struct regmap           *regmap;
> >> @@ -346,6 +363,19 @@ struct isc_device {
> >>        struct isc_format               *formats_list;
> >>        u32                             controller_formats_size;
> >>        u32                             formats_list_size;
> >> +
> >> +     struct {
> >> +             struct media_pad                pads[ISC_PADS_NUM];
> >> +             struct media_device             mdev;
> >> +
> >> +             u32                             remote_pad;
> >> +     };
> >> +
> >> +     struct {
> >> +             struct v4l2_subdev              scaler_sd;
> >> +             struct media_pad                scaler_pads[ISC_SCALER_PADS_NUM];
> >> +             struct v4l2_mbus_framefmt       scaler_format[ISC_SCALER_PADS_NUM];
> >> +     };
> >>   };
> >>
> >>   extern const struct regmap_config isc_regmap_config;
> >> @@ -357,4 +387,11 @@ int isc_clk_init(struct isc_device *isc);
> >>   void isc_subdev_cleanup(struct isc_device *isc);
> >>   void isc_clk_cleanup(struct isc_device *isc);
> >>
> >> +int isc_scaler_link(struct isc_device *isc);
> >> +int isc_scaler_init(struct isc_device *isc);
> >> +int isc_mc_init(struct isc_device *isc, u32 ver);
> >> +void isc_mc_cleanup(struct isc_device *isc);
> >> +
> >> +struct isc_format *isc_find_format_by_code(struct isc_device *isc,
> >> +                                        unsigned int code, int *index);
> >>   #endif
> >> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >> index c5b9563e36cb..c244682ea22f 100644
> >> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >> @@ -553,6 +553,12 @@ static int atmel_isc_probe(struct platform_device *pdev)
> >>                        break;
> >>        }
> >>
> >> +     regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
> >> +
> >> +     ret = isc_mc_init(isc, ver);
> >> +     if (ret < 0)
> >> +             goto isc_probe_mc_init_err;
> >> +
> >>        pm_runtime_set_active(dev);
> >>        pm_runtime_enable(dev);
> >>        pm_request_idle(dev);
> >> @@ -562,7 +568,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
> >>        ret = clk_prepare_enable(isc->ispck);
> >>        if (ret) {
> >>                dev_err(dev, "failed to enable ispck: %d\n", ret);
> >> -             goto cleanup_subdev;
> >> +             goto isc_probe_mc_init_err;
> >>        }
> >>
> >>        /* ispck should be greater or equal to hclock */
> >> @@ -572,7 +578,6 @@ static int atmel_isc_probe(struct platform_device *pdev)
> >>                goto unprepare_clk;
> >>        }
> >>
> >> -     regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
> >>        dev_info(dev, "Microchip ISC version %x\n", ver);
> >>
> >>        return 0;
> >> @@ -580,6 +585,9 @@ static int atmel_isc_probe(struct platform_device *pdev)
> >>   unprepare_clk:
> >>        clk_disable_unprepare(isc->ispck);
> >>
> >> +isc_probe_mc_init_err:
> >> +     isc_mc_cleanup(isc);
> >> +
> >>   cleanup_subdev:
> >>        isc_subdev_cleanup(isc);
> >>
> >> @@ -600,6 +608,8 @@ static int atmel_isc_remove(struct platform_device *pdev)
> >>
> >>        pm_runtime_disable(&pdev->dev);
> >>
> >> +     isc_mc_cleanup(isc);
> >> +
> >>        isc_subdev_cleanup(isc);
> >>
> >>        v4l2_device_unregister(&isc->v4l2_dev);
> >> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >> index 07a80b08bc54..9dc75eed0098 100644
> >> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >> @@ -547,15 +547,23 @@ static int microchip_xisc_probe(struct platform_device *pdev)
> >>                        break;
> >>        }
> >>
> >> +     regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
> >> +
> >> +     ret = isc_mc_init(isc, ver);
> >> +     if (ret < 0)
> >> +             goto isc_probe_mc_init_err;
> >> +
> >>        pm_runtime_set_active(dev);
> >>        pm_runtime_enable(dev);
> >>        pm_request_idle(dev);
> >>
> >> -     regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver);
> >>        dev_info(dev, "Microchip XISC version %x\n", ver);
> >>
> >>        return 0;
> >>
> >> +isc_probe_mc_init_err:
> >> +     isc_mc_cleanup(isc);
> >> +
> >>   cleanup_subdev:
> >>        isc_subdev_cleanup(isc);
> >>
> >> @@ -576,6 +584,8 @@ static int microchip_xisc_remove(struct platform_device *pdev)
> >>
> >>        pm_runtime_disable(&pdev->dev);
> >>
> >> +     isc_mc_cleanup(isc);
> >> +
> >>        isc_subdev_cleanup(isc);
> >>
> >>        v4l2_device_unregister(&isc->v4l2_dev);
> >> --
> >> 2.25.1
> >>
>