media: rcar-csi2: Use the subdev active state

Create the subdevice state with v4l2_subdev_init_finalize() and
implement the init_state() operation to guarantee the state is initialized.

Store the current image format in the subdev active state and remove it
from the driver private structure.

To guarantee the same image format is applied to all source pads,
propagate the format from the sink pad to the sources, disallowing
changing format on a source pad.

To support both gen3 and gen4, which feature a different number of
source pads, introduce an helper function to return the correct number
of pads.
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20240617161135.130719-5-jacopo.mondi@ideasonboard.comSigned-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

drivers/media/platform/renesas/rcar-csi2.c

@@ -587,7 +587,8 @@ enum rcar_csi2_pads {
 struct rcar_csi2_info {
 	int (*init_phtw)(struct rcar_csi2 *priv, unsigned int mbps);
 	int (*phy_post_init)(struct rcar_csi2 *priv);
-	int (*start_receiver)(struct rcar_csi2 *priv);
+	int (*start_receiver)(struct rcar_csi2 *priv,
+			      struct v4l2_subdev_state *state);
 	void (*enter_standby)(struct rcar_csi2 *priv);
 	const struct rcsi2_mbps_reg *hsfreqrange;
 	unsigned int csi0clkfreqrange;
@@ -613,8 +614,6 @@ struct rcar_csi2 {
 
 	int channel_vc[4];
 
-	struct mutex lock; /* Protects mf and stream_count. */
-	struct v4l2_mbus_framefmt mf;
 	int stream_count;
 
 	bool cphy;
@@ -632,6 +631,16 @@ static inline struct rcar_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
 	return container_of(n, struct rcar_csi2, notifier);
 }
 
+static unsigned int rcsi2_num_pads(const struct rcar_csi2 *priv)
+{
+	/* Used together with R-Car ISP: one sink and one source pad. */
+	if (priv->info->use_isp)
+		return 2;
+
+	/* Used together with R-Car VIN: one sink and four source pads. */
+	return 5;
+}
+
 static u32 rcsi2_read(struct rcar_csi2 *priv, unsigned int reg)
 {
 	return ioread32(priv->base + reg);
@@ -808,20 +817,25 @@ static int rcsi2_get_active_lanes(struct rcar_csi2 *priv,
 	return 0;
 }
 
-static int rcsi2_start_receiver_gen3(struct rcar_csi2 *priv)
+static int rcsi2_start_receiver_gen3(struct rcar_csi2 *priv,
+				     struct v4l2_subdev_state *state)
 {
 	const struct rcar_csi2_format *format;
 	u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
+	const struct v4l2_mbus_framefmt *fmt;
 	unsigned int lanes;
 	unsigned int i;
 	int mbps, ret;
 
+	/* Use the format on the sink pad to compute the receiver config. */
+	fmt = v4l2_subdev_state_get_format(state, RCAR_CSI2_SINK);
+
 	dev_dbg(priv->dev, "Input size (%ux%u%c)\n",
-		priv->mf.width, priv->mf.height,
-		priv->mf.field == V4L2_FIELD_NONE ? 'p' : 'i');
+		fmt->width, fmt->height,
+		fmt->field == V4L2_FIELD_NONE ? 'p' : 'i');
 
 	/* Code is validated in set_fmt. */
-	format = rcsi2_code_to_fmt(priv->mf.code);
+	format = rcsi2_code_to_fmt(fmt->code);
 	if (!format)
 		return -EINVAL;
 
@@ -849,11 +863,11 @@ static int rcsi2_start_receiver_gen3(struct rcar_csi2 *priv)
 			vcdt2 |= vcdt_part << ((i % 2) * 16);
 	}
 
-	if (priv->mf.field == V4L2_FIELD_ALTERNATE) {
+	if (fmt->field == V4L2_FIELD_ALTERNATE) {
 		fld = FLD_DET_SEL(1) | FLD_FLD_EN4 | FLD_FLD_EN3 | FLD_FLD_EN2
 			| FLD_FLD_EN;
 
-		if (priv->mf.height == 240)
+		if (fmt->height == 240)
 			fld |= FLD_FLD_NUM(0);
 		else
 			fld |= FLD_FLD_NUM(1);
@@ -1049,15 +1063,18 @@ static int rcsi2_c_phy_setting_v4h(struct rcar_csi2 *priv, int msps)
 	return 0;
 }
 
-static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv)
+static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv,
+				    struct v4l2_subdev_state *state)
 {
 	const struct rcar_csi2_format *format;
+	const struct v4l2_mbus_framefmt *fmt;
 	unsigned int lanes;
 	int msps;
 	int ret;
 
-	/* Calculate parameters */
-	format = rcsi2_code_to_fmt(priv->mf.code);
+	/* Use the format on the sink pad to compute the receiver config. */
+	fmt = v4l2_subdev_state_get_format(state, RCAR_CSI2_SINK);
+	format = rcsi2_code_to_fmt(fmt->code);
 	if (!format)
 		return -EINVAL;
 
@@ -1114,7 +1131,7 @@ static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv)
 	return 0;
 }
 
-static int rcsi2_start(struct rcar_csi2 *priv)
+static int rcsi2_start(struct rcar_csi2 *priv, struct v4l2_subdev_state *state)
 {
 	int ret;
 
@@ -1122,7 +1139,7 @@ static int rcsi2_start(struct rcar_csi2 *priv)
 	if (ret < 0)
 		return ret;
 
-	ret = priv->info->start_receiver(priv);
+	ret = priv->info->start_receiver(priv, state);
 	if (ret) {
 		rcsi2_enter_standby(priv);
 		return ret;
@@ -1146,17 +1163,16 @@ static void rcsi2_stop(struct rcar_csi2 *priv)
 static int rcsi2_s_stream(struct v4l2_subdev *sd, int enable)
 {
 	struct rcar_csi2 *priv = sd_to_csi2(sd);
+	struct v4l2_subdev_state *state;
 	int ret = 0;
 
-	mutex_lock(&priv->lock);
+	if (!priv->remote)
+		return -ENODEV;
 
-	if (!priv->remote) {
-		ret = -ENODEV;
-		goto out;
-	}
+	state = v4l2_subdev_lock_and_get_active_state(&priv->subdev);
 
 	if (enable && priv->stream_count == 0) {
-		ret = rcsi2_start(priv);
+		ret = rcsi2_start(priv, state);
 		if (ret)
 			goto out;
 	} else if (!enable && priv->stream_count == 1) {
@@ -1165,49 +1181,29 @@ static int rcsi2_s_stream(struct v4l2_subdev *sd, int enable)
 
 	priv->stream_count += enable ? 1 : -1;
 out:
-	mutex_unlock(&priv->lock);
+	v4l2_subdev_unlock_state(state);
 
 	return ret;
 }
 
 static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
-				struct v4l2_subdev_state *sd_state,
+				struct v4l2_subdev_state *state,
 				struct v4l2_subdev_format *format)
 {
 	struct rcar_csi2 *priv = sd_to_csi2(sd);
-	struct v4l2_mbus_framefmt *framefmt;
+	unsigned int num_pads = rcsi2_num_pads(priv);
 
-	mutex_lock(&priv->lock);
+	if (format->pad > RCAR_CSI2_SINK)
+		return v4l2_subdev_get_fmt(sd, state, format);
 
 	if (!rcsi2_code_to_fmt(format->format.code))
 		format->format.code = rcar_csi2_formats[0].code;
 
-	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
-		priv->mf = format->format;
-	} else {
-		framefmt = v4l2_subdev_state_get_format(sd_state, 0);
-		*framefmt = format->format;
-	}
-
-	mutex_unlock(&priv->lock);
-
-	return 0;
-}
-
-static int rcsi2_get_pad_format(struct v4l2_subdev *sd,
-				struct v4l2_subdev_state *sd_state,
-				struct v4l2_subdev_format *format)
-{
-	struct rcar_csi2 *priv = sd_to_csi2(sd);
-
-	mutex_lock(&priv->lock);
-
-	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE)
-		format->format = priv->mf;
-	else
-		format->format = *v4l2_subdev_state_get_format(sd_state, 0);
+	*v4l2_subdev_state_get_format(state, format->pad) = format->format;
 
-	mutex_unlock(&priv->lock);
+	/* Propagate the format to the source pads. */
+	for (unsigned int i = RCAR_CSI2_SOURCE_VC0; i < num_pads; i++)
+		*v4l2_subdev_state_get_format(state, i) = format->format;
 
 	return 0;
 }
@@ -1218,7 +1214,7 @@ static const struct v4l2_subdev_video_ops rcar_csi2_video_ops = {
 
 static const struct v4l2_subdev_pad_ops rcar_csi2_pad_ops = {
 	.set_fmt = rcsi2_set_pad_format,
-	.get_fmt = rcsi2_get_pad_format,
+	.get_fmt = v4l2_subdev_get_fmt,
 };
 
 static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
@@ -1226,6 +1222,33 @@ static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
 	.pad	= &rcar_csi2_pad_ops,
 };
 
+static int rcsi2_init_state(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_state *state)
+{
+	struct rcar_csi2 *priv = sd_to_csi2(sd);
+	unsigned int num_pads = rcsi2_num_pads(priv);
+
+	static const struct v4l2_mbus_framefmt rcar_csi2_default_fmt = {
+		.width		= 1920,
+		.height		= 1080,
+		.code		= MEDIA_BUS_FMT_RGB888_1X24,
+		.colorspace	= V4L2_COLORSPACE_SRGB,
+		.field		= V4L2_FIELD_NONE,
+		.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
+		.quantization	= V4L2_QUANTIZATION_DEFAULT,
+		.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
+	};
+
+	for (unsigned int i = RCAR_CSI2_SINK; i < num_pads; i++)
+		*v4l2_subdev_state_get_format(state, i) = rcar_csi2_default_fmt;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops rcar_csi2_internal_ops = {
+	.init_state = rcsi2_init_state,
+};
+
 static irqreturn_t rcsi2_irq(int irq, void *data)
 {
 	struct rcar_csi2 *priv = data;
@@ -1251,14 +1274,17 @@ static irqreturn_t rcsi2_irq(int irq, void *data)
 
 static irqreturn_t rcsi2_irq_thread(int irq, void *data)
 {
+	struct v4l2_subdev_state *state;
 	struct rcar_csi2 *priv = data;
 
-	mutex_lock(&priv->lock);
+	state = v4l2_subdev_lock_and_get_active_state(&priv->subdev);
+
 	rcsi2_stop(priv);
 	usleep_range(1000, 2000);
-	if (rcsi2_start(priv))
+	if (rcsi2_start(priv, state))
 		dev_warn(priv->dev, "Failed to restart CSI-2 receiver\n");
-	mutex_unlock(&priv->lock);
+
+	v4l2_subdev_unlock_state(state);
 
 	return IRQ_HANDLED;
 }
@@ -1870,23 +1896,23 @@ static int rcsi2_probe(struct platform_device *pdev)
 
 	priv->dev = &pdev->dev;
 
-	mutex_init(&priv->lock);
 	priv->stream_count = 0;
 
 	ret = rcsi2_probe_resources(priv, pdev);
 	if (ret) {
 		dev_err(priv->dev, "Failed to get resources\n");
-		goto error_mutex;
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, priv);
 
 	ret = rcsi2_parse_dt(priv);
 	if (ret)
-		goto error_mutex;
+		return ret;
 
 	priv->subdev.owner = THIS_MODULE;
 	priv->subdev.dev = &pdev->dev;
+	priv->subdev.internal_ops = &rcar_csi2_internal_ops;
 	v4l2_subdev_init(&priv->subdev, &rcar_csi2_subdev_ops);
 	v4l2_set_subdevdata(&priv->subdev, &pdev->dev);
 	snprintf(priv->subdev.name, sizeof(priv->subdev.name), "%s %s",
@@ -1896,7 +1922,7 @@ static int rcsi2_probe(struct platform_device *pdev)
 	priv->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
 	priv->subdev.entity.ops = &rcar_csi2_entity_ops;
 
-	num_pads = priv->info->use_isp ? 2 : NR_OF_RCAR_CSI2_PAD;
+	num_pads = rcsi2_num_pads(priv);
 
 	priv->pads[RCAR_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
 	for (i = RCAR_CSI2_SOURCE_VC0; i < num_pads; i++)
@@ -1912,21 +1938,25 @@ static int rcsi2_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(&pdev->dev);
 
+	ret = v4l2_subdev_init_finalize(&priv->subdev);
+	if (ret)
+		goto error_pm_runtime;
+
 	ret = v4l2_async_register_subdev(&priv->subdev);
 	if (ret < 0)
-		goto error_pm_runtime;
+		goto error_subdev;
 
 	dev_info(priv->dev, "%d lanes found\n", priv->lanes);
 
 	return 0;
 
+error_subdev:
+	v4l2_subdev_cleanup(&priv->subdev);
 error_pm_runtime:
 	pm_runtime_disable(&pdev->dev);
 error_async:
 	v4l2_async_nf_unregister(&priv->notifier);
 	v4l2_async_nf_cleanup(&priv->notifier);
-error_mutex:
-	mutex_destroy(&priv->lock);
 
 	return ret;
 }
@@ -1941,8 +1971,6 @@ static void rcsi2_remove(struct platform_device *pdev)
 	v4l2_subdev_cleanup(&priv->subdev);
 
 	pm_runtime_disable(&pdev->dev);
-
-	mutex_destroy(&priv->lock);
 }
 
 static struct platform_driver rcar_csi2_pdrv = {