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From: Jai Luthra <j-luthra@ti.com>
Date: Thu, 22 Feb 2024 17:01:24 +0530
Subject: [PATCH RFC 08/21] media: ti: j721e-csi2rx: add a subdev for the
 core device
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Message-ID: <20240222-multistream-v1-8-1837ed916eeb@ti.com>
References: <20240222-multistream-v1-0-1837ed916eeb@ti.com>
In-Reply-To: <20240222-multistream-v1-0-1837ed916eeb@ti.com>
To: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
        Mauro Carvalho Chehab
	<mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Hans
 Verkuil <hverkuil-cisco@xs4all.nl>,
        Vaishnav Achath <vaishnav.a@ti.com>,
        Maxime Ripard <mripard@kernel.org>, Rob Herring <robh@kernel.org>,
        Krzysztof
 Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley
	<conor+dt@kernel.org>
CC: <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, Vignesh Raghavendra <vigneshr@ti.com>,
        Aradhya
 Bhatia <a-bhatia1@ti.com>, Devarsh Thakkar <devarsht@ti.com>,
        Changhuang
 Liang <changhuang.liang@starfivetech.com>,
        Jack Zhu
	<jack.zhu@starfivetech.com>,
        Julien Massot <julien.massot@collabora.com>,
        Jayshri Pawar <jpawar@cadence.com>, Jai Luthra <j-luthra@ti.com>

With single stream capture, it was simpler to use the video device as
the media entity representing the main TI CSI2RX device. Now with multi
stream capture coming into the picture, the model has shifted to each
video device having a link to the main device's subdev. The routing
would then be set on this subdev.

Add this subdev, link each context to this subdev's entity and link the
subdev's entity to the source. Also add an array of media pads. It will
have one sink pad and source pads equal to the number of contexts.

Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 217 +++++++++++++++++++--
 1 file changed, 198 insertions(+), 19 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 80d7066100bf..42eb1bff21e2 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -51,6 +51,11 @@
 #define MAX_WIDTH_BYTES			SZ_16K
 #define MAX_HEIGHT_LINES		SZ_16K
 
+#define TI_CSI2RX_PAD_SINK		0
+#define TI_CSI2RX_PAD_FIRST_SOURCE	1
+#define TI_CSI2RX_NUM_SOURCE_PADS	1
+#define TI_CSI2RX_NUM_PADS		(1 + TI_CSI2RX_NUM_SOURCE_PADS)
+
 #define DRAIN_TIMEOUT_MS		50
 #define DRAIN_BUFFER_SIZE		SZ_32K
 
@@ -97,6 +102,7 @@ struct ti_csi2rx_ctx {
 	struct mutex			mutex; /* To serialize ioctls. */
 	struct v4l2_format		v_fmt;
 	struct ti_csi2rx_dma		dma;
+	struct media_pad		pad;
 	u32				sequence;
 	u32				idx;
 };
@@ -104,12 +110,15 @@ struct ti_csi2rx_ctx {
 struct ti_csi2rx_dev {
 	struct device			*dev;
 	void __iomem			*shim;
+	struct mutex			mutex; /* To serialize ioctls. */
+	unsigned int			enable_count;
 	struct v4l2_device		v4l2_dev;
 	struct media_device		mdev;
 	struct media_pipeline		pipe;
-	struct media_pad		pad;
+	struct media_pad		pads[TI_CSI2RX_NUM_PADS];
 	struct v4l2_async_notifier	notifier;
 	struct v4l2_subdev		*source;
+	struct v4l2_subdev		subdev;
 	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_NUM_CTX];
 	/* Buffer to drain stale data from PSI-L endpoint */
 	struct {
@@ -455,6 +464,15 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
 	int ret, i;
 
+	/* Create link from source to subdev */
+	ret = v4l2_create_fwnode_links_to_pad(csi->source,
+					      &csi->pads[TI_CSI2RX_PAD_SINK],
+					      MEDIA_LNK_FL_IMMUTABLE |
+					      MEDIA_LNK_FL_ENABLED);
+	if (ret)
+		return ret;
+
+	/* Create and link video nodes for all DMA contexts */
 	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
 		struct ti_csi2rx_ctx *ctx = &csi->ctx[i];
 		struct video_device *vdev = &ctx->vdev;
@@ -462,13 +480,17 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 		ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
 		if (ret)
 			goto unregister_dev;
-	}
 
-	ret = v4l2_create_fwnode_links_to_pad(csi->source, &csi->pad,
-					      MEDIA_LNK_FL_IMMUTABLE |
-					      MEDIA_LNK_FL_ENABLED);
-	if (ret)
-		goto unregister_dev;
+		ret = media_create_pad_link(&csi->subdev.entity,
+					    TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
+					    &vdev->entity, 0,
+					    MEDIA_LNK_FL_IMMUTABLE |
+					    MEDIA_LNK_FL_ENABLED);
+		if (ret) {
+			video_unregister_device(vdev);
+			goto unregister_dev;
+		}
+	}
 
 	ret = v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
 	if (ret)
@@ -883,7 +905,7 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
-	ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
+	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 1);
 	if (ret)
 		goto err_dma;
 
@@ -911,7 +933,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 
-	ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
+	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 0);
 	if (ret)
 		dev_err(csi->dev, "Failed to stop subdev stream\n");
 
@@ -929,6 +951,119 @@ static const struct vb2_ops csi_vb2_qops = {
 	.wait_finish = vb2_ops_wait_finish,
 };
 
+static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ti_csi2rx_dev, subdev);
+}
+
+static int ti_csi2rx_sd_set_fmt(struct v4l2_subdev *sd,
+				struct v4l2_subdev_state *state,
+				struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *fmt;
+	int ret = 0;
+
+	/* No transcoding, don't allow setting source fmt */
+	if (format->pad >= TI_CSI2RX_PAD_FIRST_SOURCE)
+		return v4l2_subdev_get_fmt(sd, state, format);
+
+	if (!find_format_by_code(format->format.code))
+		format->format.code = ti_csi2rx_formats[0].code;
+
+	format->format.field = V4L2_FIELD_NONE;
+
+	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
+	if (!fmt) {
+		ret = -EINVAL;
+		goto out;
+	}
+	*fmt = format->format;
+
+	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE,
+					   format->stream);
+	if (!fmt) {
+		ret = -EINVAL;
+		goto out;
+	}
+	*fmt = format->format;
+
+out:
+	return ret;
+}
+
+static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_state *state)
+{
+	struct v4l2_subdev_format format = {
+		.pad = TI_CSI2RX_PAD_SINK,
+		.format = {
+			.width = 640,
+			.height = 480,
+			.code = MEDIA_BUS_FMT_UYVY8_1X16,
+			.field = V4L2_FIELD_NONE,
+			.colorspace = V4L2_COLORSPACE_SRGB,
+			.ycbcr_enc = V4L2_YCBCR_ENC_601,
+			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+			.xfer_func = V4L2_XFER_FUNC_SRGB,
+		},
+	};
+
+	return ti_csi2rx_sd_set_fmt(sd, state, &format);
+}
+
+static int ti_csi2rx_sd_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
+	int ret = 0;
+
+	mutex_lock(&csi->mutex);
+
+	if (enable) {
+		if (csi->enable_count > 0) {
+			csi->enable_count++;
+			goto out;
+		}
+
+		ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
+		if (ret)
+			goto out;
+
+		csi->enable_count++;
+	} else {
+		if (csi->enable_count == 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (--csi->enable_count > 0)
+			goto out;
+
+		ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
+	}
+
+out:
+	mutex_unlock(&csi->mutex);
+	return ret;
+}
+
+static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
+	.get_fmt = v4l2_subdev_get_fmt,
+	.set_fmt = ti_csi2rx_sd_set_fmt,
+};
+
+static const struct v4l2_subdev_video_ops ti_csi2rx_subdev_video_ops = {
+	.s_stream = ti_csi2rx_sd_s_stream,
+};
+
+static const struct v4l2_subdev_ops ti_csi2rx_subdev_ops = {
+	.video = &ti_csi2rx_subdev_video_ops,
+	.pad = &ti_csi2rx_subdev_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops ti_csi2rx_internal_ops = {
+	.init_state = ti_csi2rx_sd_init_state,
+};
+
 static void ti_csi2rx_cleanup_dma(struct ti_csi2rx_ctx *ctx)
 {
 	dma_release_channel(ctx->dma.chan);
@@ -936,6 +1071,7 @@ static void ti_csi2rx_cleanup_dma(struct ti_csi2rx_ctx *ctx)
 
 static void ti_csi2rx_cleanup_v4l2(struct ti_csi2rx_dev *csi)
 {
+	v4l2_subdev_cleanup(&csi->subdev);
 	media_device_unregister(&csi->mdev);
 	v4l2_device_unregister(&csi->v4l2_dev);
 	media_device_cleanup(&csi->mdev);
@@ -1001,7 +1137,7 @@ static int ti_csi2rx_link_validate(struct media_link *link)
 	const struct ti_csi2rx_fmt *ti_fmt;
 	int ret;
 
-	ret = v4l2_subdev_call_state_active(csi->source, pad,
+	ret = v4l2_subdev_call_state_active(&csi->subdev, pad,
 					    get_fmt, &source_fmt);
 	if (ret)
 		return ret;
@@ -1046,6 +1182,10 @@ static const struct media_entity_operations ti_csi2rx_video_entity_ops = {
 	.link_validate = ti_csi2rx_link_validate,
 };
 
+static const struct media_entity_operations ti_csi2rx_subdev_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
 static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 {
 	struct dma_slave_config cfg = {
@@ -1077,7 +1217,8 @@ static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 {
 	struct media_device *mdev = &csi->mdev;
-	int ret;
+	struct v4l2_subdev *sd = &csi->subdev;
+	int ret, i;
 
 	mdev->dev = csi->dev;
 	mdev->hw_revision = 1;
@@ -1089,16 +1230,50 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 
 	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
 	if (ret)
-		return ret;
+		goto cleanup_media;
 
 	ret = media_device_register(mdev);
-	if (ret) {
-		v4l2_device_unregister(&csi->v4l2_dev);
-		media_device_cleanup(mdev);
-		return ret;
-	}
+	if (ret)
+		goto unregister_v4l2;
+
+	v4l2_subdev_init(sd, &ti_csi2rx_subdev_ops);
+	sd->internal_ops = &ti_csi2rx_internal_ops;
+	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+	strscpy(sd->name, dev_name(csi->dev), sizeof(sd->name));
+	sd->dev = csi->dev;
+	sd->entity.ops = &ti_csi2rx_subdev_entity_ops;
+
+	csi->pads[TI_CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+
+	for (i = TI_CSI2RX_PAD_FIRST_SOURCE; i < TI_CSI2RX_NUM_PADS; i++)
+		csi->pads[i].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&sd->entity, ARRAY_SIZE(csi->pads),
+				     csi->pads);
+	if (ret)
+		goto unregister_media;
+
+	ret = v4l2_subdev_init_finalize(sd);
+	if (ret)
+		goto unregister_media;
+
+	ret = v4l2_device_register_subdev(&csi->v4l2_dev, sd);
+	if (ret)
+		goto cleanup_subdev;
 
 	return 0;
+
+cleanup_subdev:
+	v4l2_subdev_cleanup(sd);
+unregister_media:
+	media_device_unregister(mdev);
+unregister_v4l2:
+	v4l2_device_unregister(&csi->v4l2_dev);
+cleanup_media:
+	media_device_cleanup(mdev);
+
+	return ret;
 }
 
 static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
@@ -1125,9 +1300,9 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
 
 	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
 
-	csi->pad.flags = MEDIA_PAD_FL_SINK;
+	ctx->pad.flags = MEDIA_PAD_FL_SINK;
 	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
-	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &csi->pad);
+	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &ctx->pad);
 	if (ret)
 		return ret;
 
@@ -1183,6 +1358,8 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	if (!csi->drain.vaddr)
 		return -ENOMEM;
 
+	mutex_init(&csi->mutex);
+
 	ret = ti_csi2rx_v4l2_init(csi);
 	if (ret)
 		goto err_v4l2;
@@ -1215,6 +1392,7 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 
 err_v4l2:
+	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
 	return ret;
@@ -1235,6 +1413,7 @@ static int ti_csi2rx_remove(struct platform_device *pdev)
 
 	ti_csi2rx_cleanup_notifier(csi);
 	ti_csi2rx_cleanup_v4l2(csi);
+	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
 

-- 
2.43.0