Re: [PATCH 40/55] media: rkisp1: csi: Implement a V4L2 subdev for the CSI receiver

[Dafna Hirschfeld <dafna@fastmail.com>]

On 25.06.2022 14:03, Laurent Pinchart wrote:
>Hi Dafna,
>
>On Sat, Jun 25, 2022 at 10:00:34AM +0300, Dafna Hirschfeld wrote:
>> On 15.06.2022 04:11, Paul Elder wrote:
>> >The CSI receiver is a component separate from the ISP or the resizers.
>> >It is actually optional, not all device model include a CSI receiver. On
>> >some SoCs CSI-2 support can be provided through an external CSI-2
>> >receiver, connected to the ISP's parallel input.
>> >
>> >To support those use cases, create a V4L2 subdev to model the CSI
>> >receiver. It will allow the driver to handle both internal and external
>> >CSI receivers the same way.
>> >
>> >The next commit will plumb the CSI subdev to the rest of the driver,
>> >replacing direct function calls.
>> >
>> >Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
>> >Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> >---
>> > .../platform/rockchip/rkisp1/rkisp1-common.h  |  17 ++
>> > .../platform/rockchip/rkisp1/rkisp1-csi.c     | 287 ++++++++++++++++++
>> > .../platform/rockchip/rkisp1/rkisp1-csi.h     |   4 +
>> > .../platform/rockchip/rkisp1/rkisp1-dev.c     |   5 +
>> > 4 files changed, 313 insertions(+)
>> >
>> >diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> >index 3c55e922346e..0ab49d1feb55 100644
>> >--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> >+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
>> >@@ -68,6 +68,13 @@ enum rkisp1_rsz_pad {
>> > 	RKISP1_RSZ_PAD_MAX
>> > };
>> >
>> >+/* enum for the csi receiver pads */
>> >+enum rkisp1_csi_pad {
>> >+	RKISP1_CSI_PAD_SINK,
>> >+	RKISP1_CSI_PAD_SRC,
>> >+	RKISP1_CSI_PAD_MAX
>>
>> I'd call it RKISP1_CSI_PAD_NUM
>
>OK.
>
>> >+};
>> >+
>> > /* enum for the capture id */
>> > enum rkisp1_stream_id {
>> > 	RKISP1_MAINPATH,
>> >@@ -141,11 +148,21 @@ struct rkisp1_sensor_async {
>> >  * @rkisp1: pointer to the rkisp1 device
>> >  * @dphy: a pointer to the phy
>> >  * @is_dphy_errctrl_disabled: if dphy errctrl is disabled (avoid endless interrupt)
>> >+ * @sd: v4l2_subdev variable
>> >+ * @pads: media pads
>> >+ * @pad_cfg: configurations for the pads
>> >+ * @ops_lock: a lock for the subdev ops
>> >+ * @source: source in-use, set when starting streaming
>> >  */
>> > struct rkisp1_csi {
>> > 	struct rkisp1_device *rkisp1;
>> > 	struct phy *dphy;
>> > 	bool is_dphy_errctrl_disabled;
>> >+	struct v4l2_subdev sd;
>> >+	struct media_pad pads[RKISP1_CSI_PAD_MAX];
>> >+	struct v4l2_subdev_pad_config pad_cfg[RKISP1_CSI_PAD_MAX];
>> >+	struct mutex ops_lock; /* serialize the subdevice ops */
>> >+	struct rkisp1_sensor_async *source;
>> > };
>> >
>> > /*
>> >diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
>> >index 425a3b014089..8182694a6fe0 100644
>> >--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
>> >+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c
>> >@@ -15,10 +15,34 @@
>> > #include <linux/phy/phy-mipi-dphy.h>
>> >
>> > #include <media/v4l2-ctrls.h>
>> >+#include <media/v4l2-fwnode.h>
>> >
>> > #include "rkisp1-common.h"
>> > #include "rkisp1-csi.h"
>> >
>> >+#define RKISP1_CSI_DEV_NAME	RKISP1_DRIVER_NAME "_csi"
>> >+
>> >+#define RKISP1_CSI_DEF_FMT	MEDIA_BUS_FMT_SRGGB10_1X10
>> >+
>> >+static inline struct rkisp1_csi *to_rkisp1_csi(struct v4l2_subdev *sd)
>> >+{
>> >+	return container_of(sd, struct rkisp1_csi, sd);
>> >+}
>> >+
>> >+static struct v4l2_mbus_framefmt *
>> >+rkisp1_csi_get_pad_fmt(struct rkisp1_csi *csi,
>> >+		       struct v4l2_subdev_state *sd_state,
>> >+		       unsigned int pad, u32 which)
>> >+{
>> >+	struct v4l2_subdev_state state = {
>> >+		.pads = csi->pad_cfg
>> >+	};
>>
>> newline here
>
>I'm surprised checkpatch didn't warn. Fixed.

Maybe you need the checkpatch's '--strict' flag to catch it, don't remember

thanks,
Dafna

>
>> >+	if (which == V4L2_SUBDEV_FORMAT_TRY)
>> >+		return v4l2_subdev_get_try_format(&csi->sd, sd_state, pad);
>> >+	else
>> >+		return v4l2_subdev_get_try_format(&csi->sd, &state, pad);
>> >+}
>> >+
>> > static int rkisp1_csi_config(struct rkisp1_csi *csi,
>> > 			     const struct rkisp1_sensor_async *sensor)
>> > {
>> >@@ -185,6 +209,269 @@ irqreturn_t rkisp1_csi_isr(int irq, void *ctx)
>> > 	return IRQ_HANDLED;
>> > }
>> >
>> >+/* ----------------------------------------------------------------------------
>> >+ * Subdev pad operations
>> >+ */
>> >+
>> >+static void rkisp1_csi_set_src_fmt(struct rkisp1_csi *csi,
>> >+				   struct v4l2_subdev_state *sd_state,
>> >+				   struct v4l2_mbus_framefmt *format,
>> >+				   unsigned int which)
>> >+{
>> >+	struct v4l2_mbus_framefmt *sink_fmt;
>> >+
>> >+	/* We don't set the src format directly; take it from the sink format */
>> >+	sink_fmt = rkisp1_csi_get_pad_fmt(csi, sd_state, RKISP1_CSI_PAD_SINK,
>> >+					  which);
>> >+
>> >+	*format = *sink_fmt;
>> >+}
>> >+
>> >+static void rkisp1_csi_set_sink_fmt(struct rkisp1_csi *csi,
>> >+				    struct v4l2_subdev_state *sd_state,
>> >+				    struct v4l2_mbus_framefmt *format,
>> >+				    unsigned int which)
>> >+{
>> >+	const struct rkisp1_mbus_info *mbus_info;
>> >+	struct v4l2_mbus_framefmt *sink_fmt, *src_fmt;
>> >+
>> >+	sink_fmt = rkisp1_csi_get_pad_fmt(csi, sd_state, RKISP1_CSI_PAD_SINK,
>> >+					  which);
>> >+	src_fmt = rkisp1_csi_get_pad_fmt(csi, sd_state, RKISP1_CSI_PAD_SRC,
>> >+					 which);
>> >+
>> >+	sink_fmt->code = format->code;
>> >+
>> >+	mbus_info = rkisp1_mbus_info_get_by_code(sink_fmt->code);
>> >+	if (!mbus_info || !(mbus_info->direction & RKISP1_ISP_SD_SINK)) {
>> >+		sink_fmt->code = RKISP1_CSI_DEF_FMT;
>> >+		mbus_info = rkisp1_mbus_info_get_by_code(sink_fmt->code);
>> >+	}
>> >+
>> >+	sink_fmt->width = clamp_t(u32, format->width,
>> >+				  RKISP1_ISP_MIN_WIDTH,
>> >+				  RKISP1_ISP_MAX_WIDTH);
>> >+	sink_fmt->height = clamp_t(u32, format->height,
>> >+				   RKISP1_ISP_MIN_HEIGHT,
>> >+				   RKISP1_ISP_MAX_HEIGHT);
>> >+
>> >+	/* Propagate to source pad */
>> >+	src_fmt->code = sink_fmt->code;
>> >+	src_fmt->width = sink_fmt->width;
>> >+	src_fmt->height = sink_fmt->height;
>> >+
>>
>> why here you don't do '*src_fmt = *sink_fmt' instead of per field propaget ?
>
>You're right, the CSI-2 receiver doesn't change the format in any way,
>that would be easier.
>
>> >+	*format = *sink_fmt;
>> >+}
>> >+
>> >+static int rkisp1_csi_enum_mbus_code(struct v4l2_subdev *sd,
>> >+				     struct v4l2_subdev_state *sd_state,
>> >+				     struct v4l2_subdev_mbus_code_enum *code)
>> >+{
>> >+	unsigned int i;
>> >+	int pos = 0;
>> >+
>> >+	if (code->index >= rkisp1_mbus_info_length())
>> >+		return -EINVAL;
>> >+
>> >+	for (i = 0; i < rkisp1_mbus_info_length(); i++) {
>> >+		const struct rkisp1_mbus_info *fmt =
>> >+			rkisp1_mbus_info_get_by_index(i);
>> >+
>> >+		if (fmt->direction & RKISP1_ISP_SD_SINK)
>> >+			pos++;
>> >+
>> >+		if (code->index == pos - 1) {
>> >+			code->code = fmt->mbus_code;
>> >+			return 0;
>> >+		}
>> >+	}
>> >+
>> >+	return -EINVAL;
>> >+}
>> >+
>> >+static int rkisp1_csi_init_config(struct v4l2_subdev *sd,
>> >+				  struct v4l2_subdev_state *sd_state)
>> >+{
>> >+	struct v4l2_mbus_framefmt *sink_fmt, *src_fmt;
>> >+
>> >+	sink_fmt = v4l2_subdev_get_try_format(sd, sd_state,
>> >+					      RKISP1_CSI_PAD_SRC);
>>
>> last argument here should be RKISP1_CSI_PAD_SINK ?
>>
>> >+	sink_fmt->width = RKISP1_DEFAULT_WIDTH;
>> >+	sink_fmt->height = RKISP1_DEFAULT_HEIGHT;
>> >+	sink_fmt->field = V4L2_FIELD_NONE;
>> >+	sink_fmt->code = RKISP1_CSI_DEF_FMT;
>> >+
>> >+	src_fmt = v4l2_subdev_get_try_format(sd, sd_state,
>> >+					     RKISP1_CSI_PAD_SINK);
>>
>> last argument here should be RKISP1_CSI_PAD_SRC ?
>
>Yes, the two are swapped, I'll fix that.
>
>> >+	*src_fmt = *sink_fmt;
>> >+
>> >+	return 0;
>> >+}
>> >+
>> >+static int rkisp1_csi_get_fmt(struct v4l2_subdev *sd,
>> >+			      struct v4l2_subdev_state *sd_state,
>> >+			      struct v4l2_subdev_format *fmt)
>> >+{
>> >+	struct rkisp1_csi *csi = to_rkisp1_csi(sd);
>> >+
>> >+	mutex_lock(&csi->ops_lock);
>> >+	fmt->format = *rkisp1_csi_get_pad_fmt(csi, sd_state, fmt->pad,
>> >+					      fmt->which);
>> >+	mutex_unlock(&csi->ops_lock);
>> >+	return 0;
>> >+}
>> >+
>> >+static int rkisp1_csi_set_fmt(struct v4l2_subdev *sd,
>> >+			      struct v4l2_subdev_state *sd_state,
>> >+			      struct v4l2_subdev_format *fmt)
>> >+{
>> >+	struct rkisp1_csi *csi = to_rkisp1_csi(sd);
>> >+
>> >+	mutex_lock(&csi->ops_lock);
>> >+	if (fmt->pad == RKISP1_CSI_PAD_SINK)
>> >+		rkisp1_csi_set_sink_fmt(csi, sd_state, &fmt->format,
>> >+					fmt->which);
>> >+	else
>> >+		rkisp1_csi_set_src_fmt(csi, sd_state, &fmt->format,
>> >+				       fmt->which);
>> >+
>> >+	mutex_unlock(&csi->ops_lock);
>> >+	return 0;
>> >+}
>> >+
>> >+/* ----------------------------------------------------------------------------
>> >+ * Subdev video operations
>> >+ */
>> >+
>> >+static int rkisp1_csi_s_stream(struct v4l2_subdev *sd, int enable)
>> >+{
>> >+	struct rkisp1_csi *csi = to_rkisp1_csi(sd);
>> >+	struct rkisp1_device *rkisp1 = csi->rkisp1;
>> >+	struct media_pad *source_pad;
>> >+	struct v4l2_subdev *source;
>> >+	int ret;
>> >+
>> >+	if (!enable) {
>> >+		v4l2_subdev_call(csi->source->sd, video, s_stream,
>> >+				 false);
>> >+
>> >+		rkisp1_csi_stop(csi);
>> >+
>> >+		return ret;
>>
>> ret is uninitialized here
>
>Fixed.
>
>> >+	}
>> >+
>> >+	source_pad = media_entity_remote_source_pad(&sd->entity);
>> >+	if (IS_ERR(source_pad)) {
>> >+		dev_dbg(rkisp1->dev, "Failed to get source for CSI: %d\n", ret);
>>
>> here you should print 'ERR_PTR(source_pad)' instead of 'ret'
>
>Indeed.
>
>Thanks for catching all those mistakes.
>
>> >+		return -EPIPE;
>> >+	}
>> >+
>> >+	source = media_entity_to_v4l2_subdev(source_pad->entity);
>> >+	if (!source) {
>> >+		/* This should really not happen, so is not worth a message. */
>> >+		return -EPIPE;
>> >+	}
>> >+
>> >+	csi->source = container_of(source->asd, struct rkisp1_sensor_async,
>> >+				   asd);
>> >+
>> >+	if (csi->source->mbus_type != V4L2_MBUS_CSI2_DPHY)
>> >+		return -EINVAL;
>> >+
>> >+	mutex_lock(&csi->ops_lock);
>> >+	ret = rkisp1_csi_start(csi, csi->source);
>> >+	mutex_unlock(&csi->ops_lock);
>> >+	if (ret)
>> >+		return ret;
>> >+
>> >+	v4l2_subdev_call(csi->source->sd, video, s_stream, true);
>> >+
>> >+	return 0;
>> >+}
>> >+
>> >+/* ----------------------------------------------------------------------------
>> >+ * Registration
>> >+ */
>> >+
>> >+static const struct media_entity_operations rkisp1_csi_media_ops = {
>> >+	.link_validate = v4l2_subdev_link_validate,
>> >+};
>> >+
>> >+static const struct v4l2_subdev_video_ops rkisp1_csi_video_ops = {
>> >+	.s_stream = rkisp1_csi_s_stream,
>> >+};
>> >+
>> >+static const struct v4l2_subdev_pad_ops rkisp1_csi_pad_ops = {
>> >+	.enum_mbus_code = rkisp1_csi_enum_mbus_code,
>> >+	.init_cfg = rkisp1_csi_init_config,
>> >+	.get_fmt = rkisp1_csi_get_fmt,
>> >+	.set_fmt = rkisp1_csi_set_fmt,
>> >+};
>> >+
>> >+static const struct v4l2_subdev_ops rkisp1_csi_ops = {
>> >+	.video = &rkisp1_csi_video_ops,
>> >+	.pad = &rkisp1_csi_pad_ops,
>> >+};
>> >+
>> >+int rkisp1_csi_register(struct rkisp1_device *rkisp1)
>> >+{
>> >+	struct rkisp1_csi *csi = &rkisp1->csi;
>> >+	struct v4l2_subdev_state state = {};
>> >+	struct media_pad *pads;
>> >+	struct v4l2_subdev *sd;
>> >+	int ret;
>> >+
>> >+	csi->rkisp1 = rkisp1;
>> >+	mutex_init(&csi->ops_lock);
>> >+
>> >+	sd = &csi->sd;
>> >+	v4l2_subdev_init(sd, &rkisp1_csi_ops);
>> >+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>> >+	sd->entity.ops = &rkisp1_csi_media_ops;
>> >+	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
>> >+	sd->owner = THIS_MODULE;
>> >+	strscpy(sd->name, RKISP1_CSI_DEV_NAME, sizeof(sd->name));
>> >+
>> >+	pads = csi->pads;
>> >+	pads[RKISP1_CSI_PAD_SINK].flags = MEDIA_PAD_FL_SINK |
>> >+					  MEDIA_PAD_FL_MUST_CONNECT;
>> >+	pads[RKISP1_CSI_PAD_SRC].flags = MEDIA_PAD_FL_SOURCE |
>> >+					 MEDIA_PAD_FL_MUST_CONNECT;
>> >+
>> >+	ret = media_entity_pads_init(&sd->entity, RKISP1_CSI_PAD_MAX, pads);
>> >+	if (ret)
>> >+		goto error;
>> >+
>> >+	state.pads = csi->pad_cfg;
>> >+	rkisp1_csi_init_config(sd, &state);
>> >+
>> >+	ret = v4l2_device_register_subdev(&csi->rkisp1->v4l2_dev, sd);
>> >+	if (ret) {
>> >+		dev_err(sd->dev, "Failed to register csi receiver subdev\n");
>> >+		goto error;
>> >+	}
>> >+
>> >+	return 0;
>> >+
>> >+error:
>> >+	media_entity_cleanup(&sd->entity);
>> >+	mutex_destroy(&csi->ops_lock);
>> >+	csi->rkisp1 = NULL;
>> >+	return ret;
>> >+}
>> >+
>> >+void rkisp1_csi_unregister(struct rkisp1_device *rkisp1)
>> >+{
>> >+	struct rkisp1_csi *csi = &rkisp1->csi;
>> >+
>> >+	if (!csi->rkisp1)
>> >+		return;
>> >+
>> >+	v4l2_device_unregister_subdev(&csi->sd);
>> >+	media_entity_cleanup(&csi->sd.entity);
>> >+	mutex_destroy(&csi->ops_lock);
>> >+}
>> >+
>> > int rkisp1_csi_init(struct rkisp1_device *rkisp1)
>> > {
>> > 	struct rkisp1_csi *csi = &rkisp1->csi;
>> >diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.h
>> >index 97ce7e7959ab..ddf8e5e08f55 100644
>> >--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.h
>> >+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.h
>> >@@ -13,10 +13,14 @@
>> >
>> > struct rkisp1_device;
>> > struct rkisp1_sensor_async;
>> >+struct v4l2_subdev;
>> >
>> > int rkisp1_csi_init(struct rkisp1_device *rkisp1);
>> > void rkisp1_csi_cleanup(struct rkisp1_device *rkisp1);
>> >
>> >+int rkisp1_csi_register(struct rkisp1_device *rkisp1);
>> >+void rkisp1_csi_unregister(struct rkisp1_device *rkisp1);
>> >+
>> > int rkisp1_csi_start(struct rkisp1_csi *csi,
>> > 		     const struct rkisp1_sensor_async *sensor);
>> > void rkisp1_csi_stop(struct rkisp1_csi *csi);
>> >diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> >index 253220188abd..faf2cd4c8149 100644
>> >--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> >+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
>> >@@ -324,6 +324,7 @@ static int rkisp1_create_links(struct rkisp1_device *rkisp1)
>> >
>> > static void rkisp1_entities_unregister(struct rkisp1_device *rkisp1)
>> > {
>> >+	rkisp1_csi_unregister(rkisp1);
>> > 	rkisp1_params_unregister(rkisp1);
>> > 	rkisp1_stats_unregister(rkisp1);
>> > 	rkisp1_capture_devs_unregister(rkisp1);
>> >@@ -355,6 +356,10 @@ static int rkisp1_entities_register(struct rkisp1_device *rkisp1)
>> > 	if (ret)
>> > 		goto error;
>> >
>> >+	ret = rkisp1_csi_register(rkisp1);
>> >+	if (ret)
>> >+		goto error;
>> >+
>> > 	ret = rkisp1_create_links(rkisp1);
>> > 	if (ret)
>> > 		goto error;
>
>-- 
>Regards,
>
>Laurent Pinchart

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