[PATCH/RFC,v2,4/9] media: i2c: ar0144: Add internal image sink pad

diff --git a/drivers/media/i2c/ar0144.c b/drivers/media/i2c/ar0144.c
index e03806ed12f4..ea76d484e6d1 100644
--- a/drivers/media/i2c/ar0144.c
+++ b/drivers/media/i2c/ar0144.c
@@ -336,6 +336,12 @@ 
 
 #define AR0144_NUM_SUPPLIES			3
 
+enum ar0144_pad_ids {
+	AR0144_PAD_SOURCE = 0,
+	AR0144_PAD_IMAGE,
+	AR0144_NUM_PADS,
+};
+
 struct ar0144_model {
 	bool mono;
 };
@@ -355,6 +361,10 @@  static const struct ar0144_model ar0144_model_mono = {
 	.mono = true,
 };
 
+/*
+ * Keep the entries sorted by descending bit depth. The top entry is used as
+ * the default media bus code, as well as the native code for the image pad.
+ */
 static const struct ar0144_format_info ar0144_formats[] = {
 	{
 		.colour = MEDIA_BUS_FMT_SGRBG12_1X12,
@@ -391,7 +401,7 @@  struct ar0144 {
 	u32 valid_formats;
 
 	struct v4l2_subdev sd;
-	struct media_pad pad;
+	struct media_pad pads[AR0144_NUM_PADS];
 
 	const struct ar0144_model *model;
 
@@ -513,6 +523,7 @@  static int ar0144_start_streaming(struct ar0144 *sensor,
 	const struct v4l2_mbus_framefmt *format;
 	const struct ar0144_format_info *info;
 	const struct v4l2_rect *crop;
+	const struct v4l2_rect *compose;
 	unsigned int bin_x, bin_y;
 	int ret = 0;
 	u16 val;
@@ -523,8 +534,9 @@  static int ar0144_start_streaming(struct ar0144 *sensor,
 	 */
 	__v4l2_ctrl_grab(sensor->link_freq, true);
 
-	format = v4l2_subdev_state_get_format(state, 0);
-	crop = v4l2_subdev_state_get_crop(state, 0);
+	format = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
+	crop = v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
+	compose = v4l2_subdev_state_get_compose(state, AR0144_PAD_IMAGE);
 	info = ar0144_format_info(sensor, format->code, true);
 
 	ret = ar0144_configure_pll(sensor);
@@ -547,8 +559,8 @@  static int ar0144_start_streaming(struct ar0144 *sensor,
 	cci_write(sensor->regmap, AR0144_Y_ADDR_END,
 		  crop->top + crop->height - 1, &ret);
 
-	bin_x = crop->width / format->width;
-	bin_y = crop->height / format->height;
+	bin_x = crop->width / compose->width;
+	bin_y = crop->height / compose->height;
 
 	cci_write(sensor->regmap, AR0144_X_ODD_INC, (bin_x << 1) - 1, &ret);
 	cci_write(sensor->regmap, AR0144_Y_ODD_INC, (bin_y << 1) - 1, &ret);
@@ -828,7 +840,7 @@  static void ar0144_update_blanking(struct ar0144 *sensor,
 	unsigned int min;
 	unsigned int max;
 
-	crop = v4l2_subdev_state_get_crop(state, 0);
+	crop = v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
 
 	/*
 	 * Horizontally, the line length (in pixel clocks), programmed in the
@@ -878,9 +890,9 @@  static int ar0144_s_ctrl(struct v4l2_ctrl *ctrl)
 	 * configuration.
 	 */
 	state = v4l2_subdev_get_locked_active_state(&sensor->sd);
-	format = v4l2_subdev_state_get_format(state, 0);
+	format = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
 	info = ar0144_format_info(sensor, format->code, true);
-	crop = v4l2_subdev_state_get_crop(state, 0);
+	crop = v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
 
 	switch (ctrl->id) {
 	case V4L2_CID_VBLANK:
@@ -1104,24 +1116,44 @@  static int ar0144_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_mbus_code_enum *code)
 {
 	struct ar0144 *sensor = to_ar0144(sd);
-	unsigned int index = 0;
-	unsigned int i;
 
-	for (i = 0; i < ARRAY_SIZE(ar0144_formats); ++i) {
-		const struct ar0144_format_info *info = &ar0144_formats[i];
+	switch (code->pad) {
+	case AR0144_PAD_IMAGE: {
+		const struct ar0144_format_info *info;
 
-		if (!(sensor->valid_formats & BIT(i)))
-			continue;
+		/* The internal image pad is hardwired to the native format. */
+		if (code->index > 0)
+			return -EINVAL;
 
-		if (code->index == index) {
-			code->code = ar0144_format_code(sensor, info);
-			return 0;
-		}
-
-		index++;
+		info = &ar0144_formats[0];
+		code->code = ar0144_format_code(sensor, info);
+		return 0;
 	}
 
-	return -EINVAL;
+	case AR0144_PAD_SOURCE: {
+		unsigned int index = 0;
+		unsigned int i;
+
+		for (i = 0; i < ARRAY_SIZE(ar0144_formats); ++i) {
+			const struct ar0144_format_info *info = &ar0144_formats[i];
+
+			if (!(sensor->valid_formats & BIT(i)))
+				continue;
+
+			if (code->index == index) {
+				code->code = ar0144_format_code(sensor, info);
+				return 0;
+			}
+
+			index++;
+		}
+
+		return -EINVAL;
+	}
+
+	default:
+		return -EINVAL;
+	}
 }
 
 static int ar0144_enum_frame_size(struct v4l2_subdev *sd,
@@ -1130,26 +1162,35 @@  static int ar0144_enum_frame_size(struct v4l2_subdev *sd,
 {
 	struct ar0144 *sensor = to_ar0144(sd);
 	const struct ar0144_format_info *info;
-	const struct v4l2_rect *crop;
+	const struct v4l2_mbus_framefmt *fmt;
 
-	info = ar0144_format_info(sensor, fse->code, false);
-	if (!info)
+	if (fse->index > 0)
 		return -EINVAL;
 
-	/*
-	 * Enumerate binning/skipping. Supported factors are powers of two from
-	 * /1 to /16.
-	 */
+	switch (fse->pad) {
+	case AR0144_PAD_IMAGE:
+		if (fse->code != ar0144_format_code(sensor, &ar0144_formats[0]))
+			return -EINVAL;
 
-	if (fse->index >= 5)
+		fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_IMAGE);
+		break;
+
+	case AR0144_PAD_SOURCE:
+		info = ar0144_format_info(sensor, fse->code, false);
+		if (!info)
+			return -EINVAL;
+
+		fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
+		break;
+
+	default:
 		return -EINVAL;
+	}
 
-	crop = v4l2_subdev_state_get_crop(state, fse->pad);
-
-	fse->min_width = crop->width / (1 << fse->index);
-	fse->max_width = fse->min_width;
-	fse->min_height = crop->height / (1 << fse->index);
-	fse->max_height = fse->min_height;
+	fse->min_width = fmt->width;
+	fse->max_width = fmt->width;
+	fse->min_height = fmt->height;
+	fse->max_height = fmt->height;
 
 	return 0;
 }
@@ -1161,31 +1202,22 @@  static int ar0144_set_fmt(struct v4l2_subdev *sd,
 	struct ar0144 *sensor = to_ar0144(sd);
 	const struct ar0144_format_info *info;
 	struct v4l2_mbus_framefmt *fmt;
-	const struct v4l2_rect *crop;
-	unsigned int bin_x, bin_y;
 
 	if (v4l2_subdev_is_streaming(sd) &&
 	    format->which == V4L2_SUBDEV_FORMAT_ACTIVE)
 		return -EBUSY;
 
-	fmt = v4l2_subdev_state_get_format(state, format->pad);
-	crop = v4l2_subdev_state_get_crop(state, format->pad);
-
-	info = ar0144_format_info(sensor, format->format.code, true);
-	fmt->code = ar0144_format_code(sensor, info);
+	/* The format can only be set on the source pad. */
+	if (format->pad != AR0144_PAD_SOURCE)
+		return v4l2_subdev_get_fmt(sd, state, format);
 
 	/*
-	 * The output size results from the binning/skipping applied to the
-	 * crop rectangle. The x/y increments must be powers of 2. Clamp the
-	 * width/height first, to avoid both divisions by 0 and the undefined
-	 * behaviour of roundup_pow_of_two(0).
+	 * Only the media bus code can be updated on the source pad, dimensions
+	 * are set by the compose on the image pad rectangle.
 	 */
-	fmt->width = clamp(format->format.width, 1U, crop->width);
-	fmt->height = clamp(format->format.height, 1U, crop->height);
-	bin_x = clamp(roundup_pow_of_two(crop->width / fmt->width), 1, 16);
-	bin_y = clamp(roundup_pow_of_two(crop->height / fmt->height), 1, 16);
-	fmt->width = crop->width / bin_x;
-	fmt->height = crop->height / bin_y;
+	fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
+	info = ar0144_format_info(sensor, format->format.code, true);
+	fmt->code = ar0144_format_code(sensor, info);
 
 	format->format = *fmt;
 
@@ -1202,11 +1234,14 @@  static int ar0144_get_selection(struct v4l2_subdev *sd,
 				struct v4l2_subdev_state *state,
 				struct v4l2_subdev_selection *sel)
 {
-	switch (sel->target) {
-	case V4L2_SEL_TGT_CROP:
-		sel->r = *v4l2_subdev_state_get_crop(state, sel->pad);
-		break;
+	/*
+	 * The sensor doesn't support output crop, selection rectangles are
+	 * supported on the internal image pad only.
+	 */
+	if (sel->pad != AR0144_PAD_IMAGE)
+		return -EINVAL;
 
+	switch (sel->target) {
 	case V4L2_SEL_TGT_CROP_DEFAULT:
 		sel->r.left = (AR0144_PIXEL_ARRAY_ACTIVE_WIDTH - AR0144_DEF_WIDTH) / 2;
 		sel->r.top = (AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT - AR0144_DEF_HEIGHT) / 2;
@@ -1221,6 +1256,14 @@  static int ar0144_get_selection(struct v4l2_subdev *sd,
 		sel->r.height = AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT;
 		break;
 
+	case V4L2_SEL_TGT_CROP:
+		sel->r = *v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
+		break;
+
+	case V4L2_SEL_TGT_COMPOSE:
+		sel->r = *v4l2_subdev_state_get_compose(state, AR0144_PAD_IMAGE);
+		break;
+
 	default:
 		return -EINVAL;
 	}
@@ -1233,31 +1276,72 @@  static int ar0144_set_selection(struct v4l2_subdev *sd,
 				struct v4l2_subdev_selection *sel)
 {
 	struct v4l2_mbus_framefmt *fmt;
+	struct v4l2_rect *compose;
 	struct v4l2_rect *crop;
+	unsigned int bin_x, bin_y;
+
+	/*
+	 * The sensor doesn't support output crop, selection rectangles are
+	 * supported on the internal image pad only.
+	 */
+	if (sel->pad != AR0144_PAD_IMAGE)
+		return -EINVAL;
 
 	if (v4l2_subdev_is_streaming(sd) &&
 	    sel->which == V4L2_SUBDEV_FORMAT_ACTIVE)
 		return -EBUSY;
 
-	if (sel->target != V4L2_SEL_TGT_CROP)
+	crop = v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
+	compose = v4l2_subdev_state_get_compose(state, AR0144_PAD_IMAGE);
+
+	switch (sel->target) {
+	case V4L2_SEL_TGT_CROP:
+		crop->left = min_t(unsigned int, ALIGN(sel->r.left, 2),
+				   AR0144_PIXEL_ARRAY_ACTIVE_WIDTH -
+				   AR0144_MIN_WIDTH);
+		crop->top = min_t(unsigned int, ALIGN(sel->r.top, 2),
+				  AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT -
+				  AR0144_MIN_HEIGHT);
+		crop->width = clamp(sel->r.width, AR0144_MIN_WIDTH,
+				    AR0144_PIXEL_ARRAY_ACTIVE_WIDTH -
+				    crop->left);
+		crop->height = clamp(sel->r.height, AR0144_MIN_HEIGHT,
+				     AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT -
+				     crop->top);
+
+		sel->r = *crop;
+
+		compose->width = crop->width;
+		compose->height = crop->height;
+		break;
+
+	case V4L2_SEL_TGT_COMPOSE:
+		/*
+		 * The output size results from the binning/skipping applied to
+		 * the crop rectangle. The x/y increments must be powers of 2.
+		 * Clamp the width/height first, to avoid both divisions by 0
+		 * and the undefined behaviour of roundup_pow_of_two(0).
+		 */
+		compose->width = clamp(sel->r.width, 1U, crop->width);
+		compose->height = clamp(sel->r.height, 1U, crop->height);
+		bin_x = clamp(roundup_pow_of_two(crop->width / compose->width),
+			      1, 16);
+		bin_y = clamp(roundup_pow_of_two(crop->height / compose->height),
+			      1, 16);
+		compose->width = crop->width / bin_x;
+		compose->height = crop->height / bin_y;
+
+		sel->r = *compose;
+		break;
+
+	default:
 		return -EINVAL;
+	}
 
-	crop = v4l2_subdev_state_get_crop(state, 0);
-	fmt = v4l2_subdev_state_get_format(state, 0);
-
-	crop->left = min_t(unsigned int, ALIGN(sel->r.left, 2),
-			   AR0144_PIXEL_ARRAY_ACTIVE_WIDTH - AR0144_MIN_WIDTH);
-	crop->top = min_t(unsigned int, ALIGN(sel->r.top, 2),
-			AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT - AR0144_MIN_HEIGHT);
-	crop->width = clamp(sel->r.width, AR0144_MIN_WIDTH,
-			    AR0144_PIXEL_ARRAY_ACTIVE_WIDTH - crop->left);
-	crop->height = clamp(sel->r.height, AR0144_MIN_HEIGHT,
-			     AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT - crop->top);
-
-	sel->r = *crop;
-
-	fmt->width = crop->width;
-	fmt->height = crop->height;
+	/* Propagate the compose rectangle to the output format. */
+	fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
+	fmt->width = compose->width;
+	fmt->height = compose->height;
 
 	return 0;
 }
@@ -1271,8 +1355,11 @@  static int ar0144_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
 	struct v4l2_subdev_state *state;
 	u32 code;
 
+	if (pad != AR0144_PAD_SOURCE)
+		return -EINVAL;
+
 	state = v4l2_subdev_lock_and_get_active_state(sd);
-	fmt = v4l2_subdev_state_get_format(state, 0);
+	fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
 	code = fmt->code;
 	v4l2_subdev_unlock_state(state);
 
@@ -1352,10 +1439,35 @@  static int ar0144_entity_init_state(struct v4l2_subdev *sd,
 	struct ar0144 *sensor = to_ar0144(sd);
 	struct v4l2_mbus_framefmt *fmt;
 	struct v4l2_rect *crop;
+	struct v4l2_rect *compose;
+
+	info = &ar0144_formats[0];
+
+	fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_IMAGE);
+	fmt->width = AR0144_PIXEL_ARRAY_ACTIVE_WIDTH;
+	fmt->height = AR0144_PIXEL_ARRAY_ACTIVE_HEIGHT;
+	fmt->code = ar0144_format_code(sensor, info);
+	fmt->field = V4L2_FIELD_NONE;
+	fmt->colorspace = V4L2_COLORSPACE_RAW;
+	fmt->ycbcr_enc = V4L2_YCBCR_ENC_601;
+	fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
+	fmt->xfer_func = V4L2_XFER_FUNC_NONE;
+
+	crop = v4l2_subdev_state_get_crop(state, AR0144_PAD_IMAGE);
+	crop->left = 4;
+	crop->top = 4;
+	crop->width = AR0144_DEF_WIDTH;
+	crop->height = AR0144_DEF_HEIGHT;
+
+	compose = v4l2_subdev_state_get_compose(state, AR0144_PAD_IMAGE);
+	compose->left = 0;
+	compose->top = 0;
+	compose->width = AR0144_DEF_WIDTH;
+	compose->height = AR0144_DEF_HEIGHT;
 
 	info = ar0144_format_info(sensor, 0, true);
 
-	fmt = v4l2_subdev_state_get_format(state, 0);
+	fmt = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
 	fmt->width = AR0144_DEF_WIDTH;
 	fmt->height = AR0144_DEF_HEIGHT;
 	fmt->code = ar0144_format_code(sensor, info);
@@ -1365,12 +1477,6 @@  static int ar0144_entity_init_state(struct v4l2_subdev *sd,
 	fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
 	fmt->xfer_func = V4L2_XFER_FUNC_NONE;
 
-	crop = v4l2_subdev_state_get_crop(state, 0);
-	crop->left = 4;
-	crop->top = 4;
-	crop->width = AR0144_DEF_WIDTH;
-	crop->height = AR0144_DEF_HEIGHT;
-
 	return 0;
 }
 
@@ -1415,9 +1521,12 @@  static int ar0144_init_subdev(struct ar0144 *sensor)
 	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
 	sd->entity.ops = &ar0144_entity_ops;
 
-	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sensor->pads[AR0144_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	sensor->pads[AR0144_PAD_IMAGE].flags = MEDIA_PAD_FL_SINK
+					     | MEDIA_PAD_FL_INTERNAL;
 
-	ret = media_entity_pads_init(&sd->entity, 1, &sensor->pad);
+	ret = media_entity_pads_init(&sd->entity, ARRAY_SIZE(sensor->pads),
+				     sensor->pads);
 	if (ret)
 		return ret;
 
@@ -1435,7 +1544,7 @@  static int ar0144_init_subdev(struct ar0144 *sensor)
 	 * rate) and blanking controls.
 	 */
 	state = v4l2_subdev_lock_and_get_active_state(sd);
-	format = v4l2_subdev_state_get_format(state, 0);
+	format = v4l2_subdev_state_get_format(state, AR0144_PAD_SOURCE);
 	info = ar0144_format_info(sensor, format->code, true);
 
 	ar0144_update_link_freqs(sensor, info);