media: v4l2-subdev: add subdev-wide state struct

media: v4l2-subdev: add subdev-wide state struct

We have 'struct v4l2_subdev_pad_config' which contains configuration for
a single pad used for the TRY functionality, and an array of those
structs is passed to various v4l2_subdev_pad_ops.

I was working on subdev internal routing between pads, and realized that
there's no way to add TRY functionality for routes, which is not pad
specific configuration. Adding a separate struct for try-route config
wouldn't work either, as e.g. set-fmt needs to know the try-route
configuration to propagate the settings.

This patch adds a new struct, 'struct v4l2_subdev_state' (which at the
moment only contains the v4l2_subdev_pad_config array) and the new
struct is used in most of the places where v4l2_subdev_pad_config was
used. All v4l2_subdev_pad_ops functions taking v4l2_subdev_pad_config
are changed to instead take v4l2_subdev_state.

The changes to drivers/media/v4l2-core/v4l2-subdev.c and
include/media/v4l2-subdev.h were written by hand, and all the driver
changes were done with the semantic patch below. The spatch needs to be
applied to a select list of directories. I used the following shell
commands to apply the spatch:

dirs="drivers/media/i2c drivers/media/platform drivers/media/usb drivers/media/test-drivers/vimc drivers/media/pci drivers/staging/media"
for dir in $dirs; do spatch -j8 --dir --include-headers --no-show-diff --in-place --sp-file v4l2-subdev-state.cocci $dir; done

Note that Coccinelle chokes on a few drivers (gcc extensions?). With
minor changes we can make Coccinelle run fine, and these changes can be
reverted after spatch. The diff for these changes is:

For drivers/media/i2c/s5k5baf.c:

	@@ -1481,7 +1481,7 @@ static int s5k5baf_set_selection(struct v4l2_subdev *sd,
	 				&s5k5baf_cis_rect,
	 				v4l2_subdev_get_try_crop(sd, cfg, PAD_CIS),
	 				v4l2_subdev_get_try_compose(sd, cfg, PAD_CIS),
	-				v4l2_subdev_get_try_crop(sd, cfg, PAD_OUT)
	+				v4l2_subdev_get_try_crop(sd, cfg, PAD_OUT),
	 			};
	 		s5k5baf_set_rect_and_adjust(rects, rtype, &sel->r);
	 		return 0;

For drivers/media/platform/s3c-camif/camif-capture.c:

	@@ -1230,7 +1230,7 @@ static int s3c_camif_subdev_get_fmt(struct v4l2_subdev *sd,
	 		*mf = camif->mbus_fmt;
	 		break;

	-	case CAMIF_SD_PAD_SOURCE_C...CAMIF_SD_PAD_SOURCE_P:
	+	case CAMIF_SD_PAD_SOURCE_C:
	 		/* crop rectangle at camera interface input */
	 		mf->width = camif->camif_crop.width;
	 		mf->height = camif->camif_crop.height;
	@@ -1332,7 +1332,7 @@ static int s3c_camif_subdev_set_fmt(struct v4l2_subdev *sd,
	 		}
	 		break;

	-	case CAMIF_SD_PAD_SOURCE_C...CAMIF_SD_PAD_SOURCE_P:
	+	case CAMIF_SD_PAD_SOURCE_C:
	 		/* Pixel format can be only changed on the sink pad. */
	 		mf->code = camif->mbus_fmt.code;
	 		mf->width = crop->width;

The semantic patch is:

// <smpl>

// Change function parameter

@@
identifier func;
identifier cfg;
@@

 func(...,
-   struct v4l2_subdev_pad_config *cfg
+   struct v4l2_subdev_state *sd_state
    , ...)
 {
 <...
- cfg
+ sd_state
 ...>
 }

// Change function declaration parameter

@@
identifier func;
identifier cfg;
type T;
@@
T func(...,
-   struct v4l2_subdev_pad_config *cfg
+   struct v4l2_subdev_state *sd_state
    , ...);

// Change function return value

@@
identifier func;
@@
- struct v4l2_subdev_pad_config
+ struct v4l2_subdev_state
 *func(...)
 {
    ...
 }

// Change function declaration return value

@@
identifier func;
@@
- struct v4l2_subdev_pad_config
+ struct v4l2_subdev_state
 *func(...);

// Some drivers pass a local pad_cfg for a single pad to a called function. Wrap it
// inside a pad_state.

@@
identifier func;
identifier pad_cfg;
@@
func(...)
{
    ...
    struct v4l2_subdev_pad_config pad_cfg;
+   struct v4l2_subdev_state pad_state = { .pads = &pad_cfg };

    <+...

(
    v4l2_subdev_call
|
    sensor_call
|
    isi_try_fse
|
    isc_try_fse
|
    saa_call_all
)
    (...,
-   &pad_cfg
+   &pad_state
    ,...)

    ...+>
}

// If the function uses fields from pad_config, access via state->pads

@@
identifier func;
identifier state;
@@
 func(...,
    struct v4l2_subdev_state *state
    , ...)
 {
    <...
(
-   state->try_fmt
+   state->pads->try_fmt
|
-   state->try_crop
+   state->pads->try_crop
|
-   state->try_compose
+   state->pads->try_compose
)
    ...>
}

// If the function accesses the filehandle, use fh->state instead

@@
struct v4l2_subdev_fh *fh;
@@
-    fh->pad
+    fh->state

@@
struct v4l2_subdev_fh fh;
@@
-    fh.pad
+    fh.state

// Start of vsp1 specific

@@
@@
struct vsp1_entity {
    ...
-    struct v4l2_subdev_pad_config *config;
+    struct v4l2_subdev_state *config;
    ...
};

@@
symbol entity;
@@
vsp1_entity_init(...)
{
    ...
    entity->config =
-    v4l2_subdev_alloc_pad_config
+    v4l2_subdev_alloc_state
    (&entity->subdev);
    ...
}

@@
symbol entity;
@@
vsp1_entity_destroy(...)
{
    ...
-   v4l2_subdev_free_pad_config
+   v4l2_subdev_free_state
    (entity->config);
    ...
}

@exists@
identifier func =~ "(^vsp1.*)|(hsit_set_format)|(sru_enum_frame_size)|(sru_set_format)|(uif_get_selection)|(uif_set_selection)|(uds_enum_frame_size)|(uds_set_format)|(brx_set_format)|(brx_get_selection)|(histo_get_selection)|(histo_set_selection)|(brx_set_selection)";
symbol config;
@@
func(...) {
    ...
-    struct v4l2_subdev_pad_config *config;
+    struct v4l2_subdev_state *config;
    ...
}

// End of vsp1 specific

// Start of rcar specific

@@
identifier sd;
identifier pad_cfg;
@@
 rvin_try_format(...)
 {
    ...
-   struct v4l2_subdev_pad_config *pad_cfg;
+   struct v4l2_subdev_state *sd_state;
    ...
-   pad_cfg = v4l2_subdev_alloc_pad_config(sd);
+   sd_state = v4l2_subdev_alloc_state(sd);
    <...
-   pad_cfg
+   sd_state
    ...>
-   v4l2_subdev_free_pad_config(pad_cfg);
+   v4l2_subdev_free_state(sd_state);
    ...
 }

// End of rcar specific

// Start of rockchip specific

@@
identifier func =~ "(rkisp1_rsz_get_pad_fmt)|(rkisp1_rsz_get_pad_crop)|(rkisp1_rsz_register)";
symbol rsz;
symbol pad_cfg;
@@

 func(...)
 {
+   struct v4l2_subdev_state state = { .pads = rsz->pad_cfg };
    ...
-   rsz->pad_cfg
+   &state
    ...
 }

@@
identifier func =~ "(rkisp1_isp_get_pad_fmt)|(rkisp1_isp_get_pad_crop)";
symbol isp;
symbol pad_cfg;
@@

 func(...)
 {
+   struct v4l2_subdev_state state = { .pads = isp->pad_cfg };
    ...
-   isp->pad_cfg
+   &state
    ...
 }

@@
symbol rkisp1;
symbol isp;
symbol pad_cfg;
@@

 rkisp1_isp_register(...)
 {
+   struct v4l2_subdev_state state = { .pads = rkisp1->isp.pad_cfg };
    ...
-   rkisp1->isp.pad_cfg
+   &state
    ...
 }

// End of rockchip specific

// Start of tegra-video specific

@@
identifier sd;
identifier pad_cfg;
@@
 __tegra_channel_try_format(...)
 {
    ...
-   struct v4l2_subdev_pad_config *pad_cfg;
+   struct v4l2_subdev_state *sd_state;
    ...
-   pad_cfg = v4l2_subdev_alloc_pad_config(sd);
+   sd_state = v4l2_subdev_alloc_state(sd);
    <...
-   pad_cfg
+   sd_state
    ...>
-   v4l2_subdev_free_pad_config(pad_cfg);
+   v4l2_subdev_free_state(sd_state);
    ...
 }

@@
identifier sd_state;
@@
 __tegra_channel_try_format(...)
 {
    ...
    struct v4l2_subdev_state *sd_state;
    <...
-   sd_state->try_crop
+   sd_state->pads->try_crop
    ...>
 }

// End of tegra-video specific

// </smpl>

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>