Subject: [PATCH 03/16] media: sun6i-mipi-csi2: Use V4L2 subdev active state

From: Paul Kocialkowski <[email-masked]>
Date: Mon, 18 May 2026 12:24:38 +0200

From: Arash Golgol <[email-masked]>

Use the V4L2 subdev active state API to store the active format.
This simplifies the driver not only by dropping the bridge mbus_format
field, but it also allows dropping the bridge lock, replaced with
the state lock.

The sun6i-mipi-csi2 hardware does not perform any format conversion.
Enforce identical formats on the sink and source pads in the set_fmt()
and init_state() callbacks.

Signed-off-by: Arash Golgol <[email-masked]>
Reviewed-by: Laurent Pinchart <[email-masked]>
---
 .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c   | 107 +++++++++---------
 .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h   |   2 -
 2 files changed, 53 insertions(+), 56 deletions(-)

diff --git a/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c b/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c
index b06cb73015cd..682bdd82098c 100644
--- a/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c
+++ b/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c
@@ -95,12 +95,12 @@ static void sun6i_mipi_csi2_disable(struct sun6i_mipi_csi2_device *csi2_dev)
 			   SUN6I_MIPI_CSI2_CTL_EN, 0);
 }
 
-static void sun6i_mipi_csi2_configure(struct sun6i_mipi_csi2_device *csi2_dev)
+static void sun6i_mipi_csi2_configure(struct sun6i_mipi_csi2_device *csi2_dev,
+				       const struct v4l2_mbus_framefmt *mbus_format)
 {
 	struct regmap *regmap = csi2_dev->regmap;
 	unsigned int lanes_count =
 		csi2_dev->bridge.endpoint.bus.mipi_csi2.num_data_lanes;
-	struct v4l2_mbus_framefmt *mbus_format = &csi2_dev->bridge.mbus_format;
 	const struct sun6i_mipi_csi2_format *format;
 	struct device *dev = csi2_dev->dev;
 	u32 version = 0;
@@ -173,7 +173,8 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 	struct v4l2_subdev *source_subdev = csi2_dev->bridge.source_subdev;
 	union phy_configure_opts dphy_opts = { 0 };
 	struct phy_configure_opts_mipi_dphy *dphy_cfg = &dphy_opts.mipi_dphy;
-	struct v4l2_mbus_framefmt *mbus_format = &csi2_dev->bridge.mbus_format;
+	struct v4l2_subdev_state *state;
+	const struct v4l2_mbus_framefmt *mbus_format;
 	const struct sun6i_mipi_csi2_format *format;
 	struct phy *dphy = csi2_dev->dphy;
 	struct device *dev = csi2_dev->dev;
@@ -183,8 +184,12 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 	unsigned long pixel_rate;
 	int ret;
 
-	if (!source_subdev)
-		return -ENODEV;
+	state = v4l2_subdev_lock_and_get_active_state(subdev);
+
+	if (!source_subdev) {
+		ret = -ENODEV;
+		goto unlock;
+	}
 
 	if (!on) {
 		v4l2_subdev_call(source_subdev, video, s_stream, 0);
@@ -196,7 +201,7 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 
 	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
-		return ret;
+		goto unlock;
 
 	/* Sensor Pixel Rate */
 
@@ -222,6 +227,8 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 		goto error_pm;
 	}
 
+	mbus_format = v4l2_subdev_state_get_format(state,
+						   SUN6I_MIPI_CSI2_PAD_SINK);
 	format = sun6i_mipi_csi2_format_find(mbus_format->code);
 	if (WARN_ON(!format)) {
 		ret = -ENODEV;
@@ -260,7 +267,7 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 
 	/* Controller */
 
-	sun6i_mipi_csi2_configure(csi2_dev);
+	sun6i_mipi_csi2_configure(csi2_dev, mbus_format);
 	sun6i_mipi_csi2_enable(csi2_dev);
 
 	/* D-PHY */
@@ -277,7 +284,8 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 	if (ret && ret != -ENOIOCTLCMD)
 		goto disable;
 
-	return 0;
+	ret = 0;
+	goto unlock;
 
 disable:
 	phy_power_off(dphy);
@@ -286,6 +294,8 @@ static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
 error_pm:
 	pm_runtime_put(dev);
 
+unlock:
+	v4l2_subdev_unlock_state(state);
 	return ret;
 }
 
@@ -308,21 +318,23 @@ sun6i_mipi_csi2_mbus_format_prepare(struct v4l2_mbus_framefmt *mbus_format)
 static int sun6i_mipi_csi2_init_state(struct v4l2_subdev *subdev,
 				      struct v4l2_subdev_state *state)
 {
-	struct sun6i_mipi_csi2_device *csi2_dev = v4l2_get_subdevdata(subdev);
-	unsigned int pad = SUN6I_MIPI_CSI2_PAD_SINK;
-	struct v4l2_mbus_framefmt *mbus_format =
-		v4l2_subdev_state_get_format(state, pad);
-	struct mutex *lock = &csi2_dev->bridge.lock;
+	unsigned int pad;
 
-	mutex_lock(lock);
+	/*
+	 * This subdev does not perform format conversion,
+	 * initialize both pads identically.
+	 */
+	for (pad = 0; pad < subdev->entity.num_pads; pad++) {
+		struct v4l2_mbus_framefmt *mbus_format;
 
-	mbus_format->code = sun6i_mipi_csi2_formats[0].mbus_code;
-	mbus_format->width = 640;
-	mbus_format->height = 480;
+		mbus_format = v4l2_subdev_state_get_format(state, pad);
 
-	sun6i_mipi_csi2_mbus_format_prepare(mbus_format);
+		mbus_format->code = sun6i_mipi_csi2_formats[0].mbus_code;
+		mbus_format->width = 640;
+		mbus_format->height = 480;
 
-	mutex_unlock(lock);
+		sun6i_mipi_csi2_mbus_format_prepare(mbus_format);
+	}
 
 	return 0;
 }
@@ -340,53 +352,32 @@ sun6i_mipi_csi2_enum_mbus_code(struct v4l2_subdev *subdev,
 	return 0;
 }
 
-static int sun6i_mipi_csi2_get_fmt(struct v4l2_subdev *subdev,
-				   struct v4l2_subdev_state *state,
-				   struct v4l2_subdev_format *format)
-{
-	struct sun6i_mipi_csi2_device *csi2_dev = v4l2_get_subdevdata(subdev);
-	struct v4l2_mbus_framefmt *mbus_format = &format->format;
-	struct mutex *lock = &csi2_dev->bridge.lock;
-
-	mutex_lock(lock);
-
-	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
-		*mbus_format = *v4l2_subdev_state_get_format(state,
-							     format->pad);
-	else
-		*mbus_format = csi2_dev->bridge.mbus_format;
-
-	mutex_unlock(lock);
-
-	return 0;
-}
-
 static int sun6i_mipi_csi2_set_fmt(struct v4l2_subdev *subdev,
 				   struct v4l2_subdev_state *state,
 				   struct v4l2_subdev_format *format)
 {
-	struct sun6i_mipi_csi2_device *csi2_dev = v4l2_get_subdevdata(subdev);
-	struct v4l2_mbus_framefmt *mbus_format = &format->format;
-	struct mutex *lock = &csi2_dev->bridge.lock;
+	struct v4l2_mbus_framefmt *fmt;
 
-	mutex_lock(lock);
+	/* The format on the source pad always matches the sink pad. */
+	if (format->pad != SUN6I_MIPI_CSI2_PAD_SINK)
+		return v4l2_subdev_get_fmt(subdev, state, format);
 
-	sun6i_mipi_csi2_mbus_format_prepare(mbus_format);
+	sun6i_mipi_csi2_mbus_format_prepare(&format->format);
 
-	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
-		*v4l2_subdev_state_get_format(state, format->pad) =
-			*mbus_format;
-	else
-		csi2_dev->bridge.mbus_format = *mbus_format;
+	/* Set the format on the sink pad. */
+	fmt = v4l2_subdev_state_get_format(state, format->pad);
+	*fmt = format->format;
 
-	mutex_unlock(lock);
+	/* Propagate the format to the source pad. */
+	fmt = v4l2_subdev_state_get_format(state, SUN6I_MIPI_CSI2_PAD_SOURCE);
+	*fmt = format->format;
 
 	return 0;
 }
 
 static const struct v4l2_subdev_pad_ops sun6i_mipi_csi2_pad_ops = {
 	.enum_mbus_code	= sun6i_mipi_csi2_enum_mbus_code,
-	.get_fmt	= sun6i_mipi_csi2_get_fmt,
+	.get_fmt	= v4l2_subdev_get_fmt,
 	.set_fmt	= sun6i_mipi_csi2_set_fmt,
 };
 
@@ -502,8 +493,6 @@ static int sun6i_mipi_csi2_bridge_setup(struct sun6i_mipi_csi2_device *csi2_dev)
 	bool notifier_registered = false;
 	int ret;
 
-	mutex_init(&bridge->lock);
-
 	/* V4L2 Subdev */
 
 	v4l2_subdev_init(subdev, &sun6i_mipi_csi2_subdev_ops);
@@ -532,6 +521,12 @@ static int sun6i_mipi_csi2_bridge_setup(struct sun6i_mipi_csi2_device *csi2_dev)
 	if (ret)
 		return ret;
 
+	/* V4L2 Subdev finalize */
+
+	ret = v4l2_subdev_init_finalize(subdev);
+	if (ret < 0)
+		goto error_media_entity_cleanup;
+
 	/* V4L2 Async */
 
 	v4l2_async_subdev_nf_init(notifier, subdev);
@@ -565,6 +560,9 @@ static int sun6i_mipi_csi2_bridge_setup(struct sun6i_mipi_csi2_device *csi2_dev)
 error_v4l2_notifier_cleanup:
 	v4l2_async_nf_cleanup(notifier);
 
+	v4l2_subdev_cleanup(subdev);
+
+error_media_entity_cleanup:
 	media_entity_cleanup(&subdev->entity);
 
 	return ret;
@@ -579,6 +577,7 @@ sun6i_mipi_csi2_bridge_cleanup(struct sun6i_mipi_csi2_device *csi2_dev)
 	v4l2_async_unregister_subdev(subdev);
 	v4l2_async_nf_unregister(notifier);
 	v4l2_async_nf_cleanup(notifier);
+	v4l2_subdev_cleanup(subdev);
 	media_entity_cleanup(&subdev->entity);
 }
 
diff --git a/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h b/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h
index 24b15e34b5e8..d72dfbd6a993 100644
--- a/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h
+++ b/drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h
@@ -32,8 +32,6 @@ struct sun6i_mipi_csi2_bridge {
 	struct media_pad		pads[SUN6I_MIPI_CSI2_PAD_COUNT];
 	struct v4l2_fwnode_endpoint	endpoint;
 	struct v4l2_async_notifier	notifier;
-	struct v4l2_mbus_framefmt	mbus_format;
-	struct mutex			lock; /* Mbus format lock. */
 
 	struct v4l2_subdev		*source_subdev;
 };
-- 
2.54.0