On 7/25/19 4:56 PM, Benjamin Gaignard wrote:
> Le jeu. 25 juil. 2019 à 13:40, Hans Verkuil <hverkuil@xxxxxxxxx> a écrit :
>>
>> On 7/2/19 5:52 PM, Hugues Fruchet wrote:
>>> 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 <hugues.fruchet@xxxxxx>
>>> ---
>>> drivers/media/platform/stm32/stm32-dcmi.c | 204 +++++++++++++++++++++++++++---
>>> 1 file changed, 186 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
>>> index 6f37617..6921e6b 100644
>>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>>> @@ -172,6 +172,7 @@ 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)
>>> @@ -583,6 +584,131 @@ static void dcmi_buf_queue(struct vb2_buffer *vb)
>>> spin_unlock_irq(&dcmi->irqlock);
>>> }
>>>
>>> +static struct media_entity *dcmi_find_source(struct stm32_dcmi *dcmi)
>>> +{
>>> + struct media_entity *entity = &dcmi->vdev->entity;
>>> + struct media_pad *pad;
>>> +
>>> + /* Walk searching for entity having no sink */
>>> + 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;
>>> + }
>>> +
>>> + 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->entity.source->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);
>>> + 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);
>>> + 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);
>>> @@ -597,14 +723,17 @@ 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->entity.source, 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 */
>>> @@ -676,7 +805,7 @@ 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 */
>>> @@ -687,8 +816,11 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>
>>> return 0;
>>>
>>> -err_subdev_streamoff:
>>> - v4l2_subdev_call(dcmi->entity.source, 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);
>>> @@ -713,13 +845,10 @@ 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->entity.source, 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);
>>>
>>> @@ -937,8 +1066,7 @@ 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->entity.source, pad,
>>> - set_fmt, NULL, &format);
>>> + ret = dcmi_pipeline_s_fmt(dcmi, NULL, &format);
>>> if (ret < 0)
>>> return ret;
>>>
>>> @@ -1529,7 +1657,20 @@ 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 source subdevice
>>> + * in order to expose it through V4L2 interface
>>> + */
>>> + dcmi->entity.source =
>>> + media_entity_to_v4l2_subdev(dcmi_find_source(dcmi));
>>> + if (!dcmi->entity.source) {
>>> + dev_err(dcmi->dev, "Source subdevice not found\n");
>>> + return -ENODEV;
>>> + }
>>> +
>>> dcmi->vdev->ctrl_handler = dcmi->entity.source->ctrl_handler;
>>> +
>>> ret = dcmi_formats_init(dcmi);
>>> if (ret) {
>>> dev_err(dcmi->dev, "No supported mediabus format found\n");
>>> @@ -1574,12 +1715,30 @@ 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->entity.source = 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 +1798,15 @@ 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);
>>
>> This shouldn't be needed. Only MC-centric drivers (i.e. where the pipeline
>> has to be configured by userspace) need to do this.
>
> Hi Hans,
> I think this point has been discussed in this thread
> https://www.spinics.net/lists/linux-media/msg153417.html
>
> In short : since the hardware only offer one possible path we don't expose
> the configuration to userland and let DCMI driver configure the
> subdevice (like bridge).
Yes, and I agree completely. But why then do you register v4l-subdevX devices?
That's not needed for this driver.
Regards,
Hans
>
> Benjamin
>
>>
>> Otherwise this patch looks good.
>>
>> Regards,
>>
>> Hans
>>
>>> + if (ret) {
>>> + dev_err(dcmi->dev, "Failed to register subdev nodes\n");
>>> + v4l2_async_notifier_unregister(&dcmi->notifier);
>>> + of_node_put(dcmi->entity.remote_node);
>>> + return ret;
>>> + }
>>> +
>>> return 0;
>>> }
>>>
>>>
>>
