Re: [PATCH v2 3/3] media: stm32-dcmi: add support of several sub-devices
From: Hugues FRUCHET <hidden>
Date: 2019-07-02 15:27:18
Also in:
linux-media, lkml
Hi Sakari, On 6/20/19 5:54 PM, Sakari Ailus wrote:
Hi Hugues, Thank you for the update. On Tue, Jun 11, 2019 at 10:48:32AM +0200, Hugues Fruchet wrote:quoted
Add support of several sub-devices within pipeline instead of a single one. This allows to support a CSI-2 camera sensor connected through a CSI-2 to parallel bridge. Signed-off-by: Hugues Fruchet <redacted> --- drivers/media/platform/stm32/stm32-dcmi.c | 207 +++++++++++++++++++++++++++--- 1 file changed, 189 insertions(+), 18 deletions(-)diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index 3a69783..144912f 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c@@ -173,6 +173,7 @@ struct stm32_dcmi { struct media_device mdev; struct media_pad vid_cap_pad; + struct media_pipeline pipeline; }; static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n)@@ -584,6 +585,135 @@ static void dcmi_buf_queue(struct vb2_buffer *vb) spin_unlock_irq(&dcmi->irqlock); } +static struct media_entity *dcmi_find_sensor(struct stm32_dcmi *dcmi)You generally should be only concerned with the next entity connected to the one you're in control of, not the rest of the pipeline.
This was discussed with Laurent here: https://www.spinics.net/lists/linux-media/msg153417.html and it's OK because DCMI is a video node and we are not exposing media controller interface to userspace.
quoted
+{ + struct media_entity *entity = &dcmi->vdev->entity; + struct v4l2_subdev *subdev; + struct media_pad *pad; + + /* Walk searching for entity having no sink */ + while (1) { + pad = &entity->pads[0]; + + subdev = media_entity_to_v4l2_subdev(entity); + + if (!(pad->flags & MEDIA_PAD_FL_SINK)) + break; + + pad = media_entity_remote_pad(pad); + if (!pad || !is_media_entity_v4l2_subdev(pad->entity)) + break; + + entity = pad->entity; + } + + return entity; +} + +static int dcmi_pipeline_s_fmt(struct stm32_dcmi *dcmi, + struct v4l2_subdev_pad_config *pad_cfg, + struct v4l2_subdev_format *format) +{ + struct media_entity *entity = &dcmi->sensor->entity; + struct v4l2_subdev *subdev; + struct media_pad *sink_pad = NULL; + struct media_pad *src_pad = NULL; + struct media_pad *pad = NULL; + struct v4l2_subdev_format fmt = *format; + bool found = false; + int ret; + + /* + * Starting from sensor subdevice, walk within + * pipeline and set format on each subdevice + */ + while (1) { + unsigned int i; + + /* Search if current entity has a source pad */ + for (i = 0; i < entity->num_pads; i++) { + pad = &entity->pads[i]; + if (pad->flags & MEDIA_PAD_FL_SOURCE) { + src_pad = pad; + found = true; + break; + } + } + if (!found) + break; + + subdev = media_entity_to_v4l2_subdev(entity); + + /* Propagate format on sink pad if any, otherwise source pad */ + if (sink_pad) + pad = sink_pad; + + dev_dbg(dcmi->dev, "%s[%d] pad format set to 0x%x %ux%u\n", + subdev->name, pad->index, format->format.code, + format->format.width, format->format.height); + + fmt.pad = pad->index; + ret = v4l2_subdev_call(subdev, pad, set_fmt, pad_cfg, &fmt);Generally speaking, on MC-centric devices, the user space needs to configure the pipeline. The driver's responsibility is to validate it (through the link_validate media entity and subdev pad ops). I.e. set_fmt is only used through the subdev nodes.
ditto
quoted
+ if (ret < 0) + return ret; + + /* Walk to next entity */ + sink_pad = media_entity_remote_pad(src_pad); + if (!sink_pad || !is_media_entity_v4l2_subdev(sink_pad->entity)) + break; + + entity = sink_pad->entity; + } + *format = fmt; + + return 0; +} + +static int dcmi_pipeline_s_stream(struct stm32_dcmi *dcmi, int state) +{ + struct media_entity *entity = &dcmi->vdev->entity; + struct v4l2_subdev *subdev; + struct media_pad *pad; + int ret; + + /* Start/stop all entities within pipeline */ + while (1) { + pad = &entity->pads[0]; + if (!(pad->flags & MEDIA_PAD_FL_SINK)) + break; + + pad = media_entity_remote_pad(pad); + if (!pad || !is_media_entity_v4l2_subdev(pad->entity)) + break; + + entity = pad->entity; + subdev = media_entity_to_v4l2_subdev(entity); + + ret = v4l2_subdev_call(subdev, video, s_stream, state);Please only call this on the next upstream sub-device. See e.g. the ipu3-cio2 or omap3isp driver for an example.
ditto
quoted
+ if (ret < 0 && ret != -ENOIOCTLCMD) { + dev_err(dcmi->dev, "%s: %s failed to %s streaming (%d)\n", + __func__, subdev->name, + state ? "start" : "stop", ret); + return ret; + } + + dev_dbg(dcmi->dev, "%s is %s\n", + subdev->name, state ? "started" : "stopped"); + } + + return 0; +} + +static int dcmi_pipeline_start(struct stm32_dcmi *dcmi) +{ + return dcmi_pipeline_s_stream(dcmi, 1); +} + +static void dcmi_pipeline_stop(struct stm32_dcmi *dcmi) +{ + dcmi_pipeline_s_stream(dcmi, 0); +} + static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) { struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);@@ -598,14 +728,17 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) goto err_release_buffers; } - /* Enable stream on the sub device */ - ret = v4l2_subdev_call(dcmi->sensor, video, s_stream, 1); - if (ret && ret != -ENOIOCTLCMD) { - dev_err(dcmi->dev, "%s: Failed to start streaming, subdev streamon error", - __func__); + ret = media_pipeline_start(&dcmi->vdev->entity, &dcmi->pipeline); + if (ret < 0) { + dev_err(dcmi->dev, "%s: Failed to start streaming, media pipeline start error (%d)\n", + __func__, ret); goto err_pm_put; } + ret = dcmi_pipeline_start(dcmi); + if (ret) + goto err_media_pipeline_stop; + spin_lock_irq(&dcmi->irqlock); /* Set bus width */@@ -677,7 +810,7 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) if (ret) { dev_err(dcmi->dev, "%s: Start streaming failed, cannot start capture\n", __func__); - goto err_subdev_streamoff; + goto err_pipeline_stop; } /* Enable interruptions */@@ -688,8 +821,11 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) return 0; -err_subdev_streamoff: - v4l2_subdev_call(dcmi->sensor, video, s_stream, 0); +err_pipeline_stop: + dcmi_pipeline_stop(dcmi); + +err_media_pipeline_stop: + media_pipeline_stop(&dcmi->vdev->entity); err_pm_put: pm_runtime_put(dcmi->dev);@@ -714,13 +850,10 @@ static void dcmi_stop_streaming(struct vb2_queue *vq) { struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq); struct dcmi_buf *buf, *node; - int ret; - /* Disable stream on the sub device */ - ret = v4l2_subdev_call(dcmi->sensor, video, s_stream, 0); - if (ret && ret != -ENOIOCTLCMD) - dev_err(dcmi->dev, "%s: Failed to stop streaming, subdev streamoff error (%d)\n", - __func__, ret); + dcmi_pipeline_stop(dcmi); + + media_pipeline_stop(&dcmi->vdev->entity); spin_lock_irq(&dcmi->irqlock);@@ -938,8 +1071,7 @@ static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f) mf->width = sd_framesize.width; mf->height = sd_framesize.height; - ret = v4l2_subdev_call(dcmi->sensor, pad, - set_fmt, NULL, &format); + ret = dcmi_pipeline_s_fmt(dcmi, NULL, &format); if (ret < 0) return ret;@@ -1530,7 +1662,19 @@ static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier) struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier); int ret; + /* + * Now that the graph is complete, + * we search for the camera sensor subdevice + * in order to expose it through V4L2 interface + */ + dcmi->sensor = media_entity_to_v4l2_subdev(dcmi_find_sensor(dcmi)); + if (!dcmi->sensor) { + dev_err(dcmi->dev, "No camera sensor subdevice found\n"); + return -ENODEV; + } + dcmi->vdev->ctrl_handler = dcmi->sensor->ctrl_handler; + ret = dcmi_formats_init(dcmi); if (ret) { dev_err(dcmi->dev, "No supported mediabus format found\n");@@ -1574,12 +1718,30 @@ static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier, struct v4l2_async_subdev *asd) { struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier); + unsigned int ret; + int src_pad; dev_dbg(dcmi->dev, "Subdev %s bound\n", subdev->name); - dcmi->sensor = subdev; + /* + * Link this sub-device to DCMI, it could be + * a parallel camera sensor or a bridge + */ + src_pad = media_entity_get_fwnode_pad(&subdev->entity, + subdev->fwnode, + MEDIA_PAD_FL_SOURCE); + + ret = media_create_pad_link(&subdev->entity, src_pad, + &dcmi->vdev->entity, 0, + MEDIA_LNK_FL_IMMUTABLE | + MEDIA_LNK_FL_ENABLED); + if (ret) + dev_err(dcmi->dev, "Failed to create media pad link with subdev %s\n", + subdev->name); + else + dev_dbg(dcmi->dev, "DCMI is now linked to %s\n", subdev->name); - return 0; + return ret; } static const struct v4l2_async_notifier_operations dcmi_graph_notify_ops = {@@ -1639,6 +1801,15 @@ static int dcmi_graph_init(struct stm32_dcmi *dcmi) return ret; } + /* Register all the subdev nodes */ + ret = v4l2_device_register_subdev_nodes(&dcmi->v4l2_dev); + if (ret) { + dev_err(dcmi->dev, "Failed to register subdev nodes\n"); + v4l2_async_notifier_unregister(&dcmi->notifier); + of_node_put(dcmi->entity.node); + return ret; + } + return 0; }
BR, Hugues. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel