Re: [PATCH 13/15] mediactl: Add media device ioctl API

[Jacek Anaszewski <j.anaszewski@samsung.com>]

Hi Sakari,

Thanks for the review.

On 02/15/2016 01:41 PM, Sakari Ailus wrote:
> Hi Jacek,
>
> Jacek Anaszewski wrote:
>> Ioctls executed on complex media devices need special handling.
>> For instance some ioctls need to be targeted for specific sub-devices,
>> depending on the media device configuration. The APIs being introduced
>> address such requirements.
>>
>> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
>> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>   utils/media-ctl/Makefile.am          |    2 +-
>>   utils/media-ctl/libv4l2media_ioctl.c |  404 ++++++++++++++++++++++++++++++++++
>>   utils/media-ctl/libv4l2media_ioctl.h |   48 ++++
>>   3 files changed, 453 insertions(+), 1 deletion(-)
>>   create mode 100644 utils/media-ctl/libv4l2media_ioctl.c
>>   create mode 100644 utils/media-ctl/libv4l2media_ioctl.h
>>
>> diff --git a/utils/media-ctl/Makefile.am b/utils/media-ctl/Makefile.am
>> index 3e883e0..7f18624 100644
>> --- a/utils/media-ctl/Makefile.am
>> +++ b/utils/media-ctl/Makefile.am
>> @@ -1,6 +1,6 @@
>>   noinst_LTLIBRARIES = libmediactl.la libv4l2subdev.la libmediatext.la
>>
>> -libmediactl_la_SOURCES = libmediactl.c mediactl-priv.h
>> +libmediactl_la_SOURCES = libmediactl.c mediactl-priv.h libv4l2media_ioctl.c libv4l2media_ioctl.h
>>   libmediactl_la_CFLAGS = -static $(LIBUDEV_CFLAGS)
>>   libmediactl_la_LDFLAGS = -static $(LIBUDEV_LIBS)
>>
>> diff --git a/utils/media-ctl/libv4l2media_ioctl.c b/utils/media-ctl/libv4l2media_ioctl.c
>> new file mode 100644
>> index 0000000..b186121
>> --- /dev/null
>> +++ b/utils/media-ctl/libv4l2media_ioctl.c
>> @@ -0,0 +1,404 @@
>> +/*
>> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
>> + *              http://www.samsung.com
>> + *
>> + * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU Lesser General Public License as published by
>> + * the Free Software Foundation; either version 2.1 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * Lesser General Public License for more details.
>> + */
>> +
>> +#include <errno.h>
>> +#include <stdlib.h>
>> +#include <sys/syscall.h>
>> +#include <unistd.h>
>> +
>> +#include <linux/videodev2.h>
>> +
>> +#include "libv4l2media_ioctl.h"
>> +#include "mediactl-priv.h"
>> +#include "mediactl.h"
>> +#include "v4l2subdev.h"
>> +
>> +#define VIDIOC_CTRL(type)					\
>> +	((type) == VIDIOC_S_CTRL ? "VIDIOC_S_CTRL" :		\
>> +				   "VIDIOC_G_CTRL")
>> +
>> +#define VIDIOC_EXT_CTRL(type)					\
>> +	((type) == VIDIOC_S_EXT_CTRLS ? 			\
>> +		"VIDIOC_S_EXT_CTRLS"	:			\
>> +		 ((type) == VIDIOC_G_EXT_CTRLS ? 		\
>> +				    "VIDIOC_G_EXT_CTRLS" :	\
>> +				    "VIDIOC_TRY_EXT_CTRLS"))
>> +
>> +#define SYS_IOCTL(fd, cmd, arg) \
>> +	syscall(SYS_ioctl, (int)(fd), (unsigned long)(cmd), (void *)(arg))
>> +
>> +
>> +int media_ioctl_ctrl(struct media_device *media, int request,
>
> unsigned int request

OK.

>
>> +		     struct v4l2_control *arg)
>
> I wonder if it'd make sense to always use v4l2_ext_control instead. You
> can't access 64-bit integer controls with VIDIOC_S_CTRL for instance.

This function is meant to handle VIDIOC_S_CTRL/VIDIOC_G_CTRL ioctls.
For ext ctrls there is media_ioctl_ext_ctrl().

> As this is a user space library, I'd probably add a function to handle
> S/G/TRY control each.

There is media_ioctl_ext_ctrl() that handles VIDIOC_S_EXT_CTRLS,
VIDIOC_G_EXT_CTRLS and VIDIOC_TRY_EXT_CTRLS.

> Have you considered binding the control to a video node rather than a
> media device? We have many sensors on current media devices already, and
> e.g. exposure time control can be found in multiple sub-devices.

Doesn't v4l2-ctrl-redir config entry address that?

>> +{
>> +	struct media_entity *entity = media->pipeline;
>> +	struct v4l2_control ctrl = *arg;
>> +	struct v4l2_queryctrl queryctrl;
>> +	bool ctrl_found = 0;
>> +	int ret;
>> +
>> +	/*
>> +	 * The control has to be reset to the default value
>> +	 * on all of the pipeline entities, prior setting a new
>> +	 * value. This is required in cases when the control config
>> +	 * is changed between subsequent calls to VIDIOC_S_CTRL,
>> +	 * to avoid the situation when a control is set on more
>> +	 * than one sub-device.
>> +	 */
>> +	if (request == VIDIOC_S_CTRL) {
>> +		while (entity) {
>> +			queryctrl.id = ctrl.id;
>> +
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERYCTRL,
>> +					&queryctrl);
>> +			if (ret < 0) {
>> +				entity = entity->next;
>> +				continue;
>> +			}
>> +
>> +			ctrl_found = true;
>> +
>> +			if (queryctrl.type & V4L2_CTRL_TYPE_BUTTON)
>> +				break;
>> +
>> +			ctrl.value = queryctrl.default_value;
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_S_CTRL, &ctrl);
>> +			if (ret < 0)
>> +				return -EINVAL;
>> +
>> +			entity = entity->next;
>> +		}
>> +
>> +		ctrl.value = arg->value;
>> +	}
>> +
>> +	if (!ctrl_found) {
>> +		ret = -EINVAL;
>> +		goto exit;
>> +	}
>> +
>> +	entity = v4l2_subdev_get_pipeline_entity_by_cid(media, ctrl.id);
>> +
>> +	if (entity) {
>> +		ret = SYS_IOCTL(entity->sd->fd, request, &ctrl);
>> +	} else {
>> +		/* Walk the pipeline until the request succeeds */
>> +		entity = media->pipeline;
>> +
>> +		ret = -ENOENT;
>> +
>> +		while (entity) {
>> +			ret = SYS_IOCTL(entity->sd->fd, request, &ctrl);
>> +			if (!ret)
>> +				break;
>> +
>> +			entity = entity->next;
>> +		}
>> +	}
>> +
>> +exit:
>> +	*arg = ctrl;
>> +
>> +	media_dbg(media, "%s [id: 0x%8.8x, name: %s, entity: %s] (%d)\n",
>> +		  VIDIOC_CTRL(request), ctrl.id, ret ? NULL : queryctrl.name,
>> +		  entity ? entity->info.name : NULL, ret);
>> +
>> +	return ret;
>> +}
>> +
>> +static int media_ioctl_single_ext_ctrl(struct media_device *media,
>> +				int request, struct v4l2_ext_controls *arg)
>> +{
>> +	struct media_entity *entity = media->pipeline;
>> +	struct v4l2_ext_controls ctrls = *arg;
>> +	struct v4l2_ext_control *ctrl;
>> +	struct v4l2_query_ext_ctrl queryctrl;
>> +	bool ctrl_found = 0;
>> +	int ret = -EINVAL;
>> +
>> +	ctrl = &ctrls.controls[0];
>> +
>> +	/*
>> +	 * The control has to be reset to the default value
>> +	 * on all of the pipeline entities, prior setting a new
>> +	 * value. This is required in cases when the control config
>> +	 * is changed between subsequent calls to VIDIOC_S_EXT_CTRLS,
>> +	 * to avoid the situation when a control is set on more
>> +	 * than one sub-device.
>> +	 */
>> +	if (request == VIDIOC_S_EXT_CTRLS) {
>> +		while (entity) {
>> +			queryctrl.id = ctrl->id;
>> +
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERY_EXT_CTRL,
>> +					&queryctrl);
>> +			if (ret < 0) {
>> +				entity = entity->next;
>> +				continue;
>> +			}
>> +
>> +			ctrl_found = true;
>> +
>> +			if (queryctrl.type & V4L2_CTRL_TYPE_BUTTON)
>> +				break;
>> +
>> +			ctrl->value64 = queryctrl.default_value;
>> +
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_S_EXT_CTRLS,
>> +					&ctrls);
>> +			if (ret < 0)
>> +				return -EINVAL;
>> +
>> +			entity = entity->next;
>> +		}
>> +
>> +		ctrl->value64 = arg->controls[0].value64;
>> +	}
>> +
>> +	if (!ctrl_found) {
>> +		ret = -EINVAL;
>> +		goto exit;
>> +	}
>> +
>> +	entity = v4l2_subdev_get_pipeline_entity_by_cid(media, ctrl->id);
>> +
>> +	if (entity) {
>> +		ret = SYS_IOCTL(entity->sd->fd, request, &ctrls);
>> +	} else {
>> +		/* Walk the pipeline until the request succeeds */
>> +		entity = media->pipeline;
>> +
>> +		while (entity) {
>> +			ret = SYS_IOCTL(entity->sd->fd, request, &ctrls);
>> +			if (!ret)
>> +				break;
>> +
>> +			entity = entity->next;
>> +		}
>> +	}
>> +
>> +exit:
>> +	*arg = ctrls;
>> +
>> +	media_dbg(media, "%s [id: 0x%8.8x, entity: %s] (%d)\n",
>> +		  VIDIOC_EXT_CTRL(request), ctrl->id,
>> +		  entity ? entity->info.name : NULL, ret);
>> +
>> +	return ret;
>> +}
>> +
>> +int media_ioctl_ext_ctrl(struct media_device *media, int request,
>> +			 struct v4l2_ext_controls *arg)
>> +{
>> +	struct v4l2_ext_controls out_ctrls = *arg, ctrls = *arg;
>> +	int ret = -EINVAL, i;
>> +
>> +	ctrls.count = 1;
>> +
>> +	/*
>> +	 * Split cluster to individual ioctl calls for each control
>> +	 * from the array, to make possible redirection of every
>> +	 * single control to different sub-device, according to the
>> +	 * configuration settings.
>> +	 */
>> +	for (i = 0; i < arg->count; ++i) {
>> +		ctrls.controls = &arg->controls[i];
>> +
>> +		ret = media_ioctl_single_ext_ctrl(media, request, &ctrls);
>> +		out_ctrls.controls[i] = ctrls.controls[i];
>> +		if (ret < 0) {
>> +			if (ctrls.error_idx == 1)
>> +				out_ctrls.error_idx = ctrls.count;
>> +			else
>> +				out_ctrls.error_idx = i;
>> +			break;
>> +		}
>> +	}
>> +
>> +	*arg = out_ctrls;
>> +	return ret;
>> +}
>> +
>> +int sort_ctrls(const void * a, const void * b)
>> +{
>> +	const struct media_entity_to_cid *ctrl_a = a, *ctrl_b = b;
>> +
>> +	return ctrl_a->queryctrl.id - ctrl_b->queryctrl.id;
>> +}
>> +
>> +int media_ioctl_queryctrl(struct media_device *media,
>> +			  struct v4l2_queryctrl *arg)
>> +{
>> +	struct media_entity *entity = media->pipeline, *target_entity;
>> +	struct v4l2_queryctrl queryctrl = *arg;
>> +	int ret = -EINVAL, num_ctrls = 0;
>> +	struct media_entity_to_cid *ctrls_found;
>> +
>> +	/*
>> +	 * If id is or'ed with V4L2_CTRL_FLAG_NEXT_CTRL then the control to
>> +	 * be found is the one with the next lowest id among all entities
>> +	 * in the pipeline.
>> +	 */
>> +	if (queryctrl.id & V4L2_CTRL_FLAG_NEXT_CTRL) {
>> +		ctrls_found = malloc(sizeof(*ctrls_found));
>> +
>> +		while (entity) {
>> +			queryctrl = *arg;
>> +
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERYCTRL,
>> +					&queryctrl);
>> +			if (!ret) {
>> +				ctrls_found = realloc(ctrls_found,
>> +					sizeof(*ctrls_found) * (num_ctrls + 1));
>> +				ctrls_found[num_ctrls].queryctrl = queryctrl;
>> +				ctrls_found[num_ctrls].entity = entity;
>> +				++num_ctrls;
>> +			}
>> +
>> +			entity = entity->next;
>> +		}
>> +
>> +		if (num_ctrls == 0) {
>> +			ret = -EINVAL;
>> +			entity = NULL;
>> +			goto done;
>> +		}
>> +
>> +		qsort(ctrls_found, num_ctrls, sizeof(*ctrls_found), sort_ctrls);
>> +
>> +		queryctrl = ctrls_found[0].queryctrl;
>> +		target_entity = ctrls_found[0].entity;
>> +
>> +		free(ctrls_found);
>> +	}
>> +
>> +	entity = v4l2_subdev_get_pipeline_entity_by_cid(media, queryctrl.id);
>> +	if (entity)
>> +		target_entity = entity;
>> +
>> +	ret = SYS_IOCTL(target_entity->sd->fd, VIDIOC_QUERYCTRL,
>> +				&queryctrl);
>> +
>> +done:
>> +	media_dbg(media,
>> +		  "VIDIOC_QUERYCTRL [id: 0x%8.8x, name: %s, entity: %s] (%d)\n",
>> +		  ret ? arg->id : queryctrl.id, ret ? NULL : queryctrl.name,
>> +		  target_entity ? target_entity->info.name : NULL, ret);
>> +
>> +	*arg = queryctrl;
>> +
>> +	return ret;
>> +}
>> +
>> +int media_ioctl_query_ext_ctrl(struct media_device *media,
>> +			       struct v4l2_query_ext_ctrl *arg)
>> +{
>> +	struct media_entity *entity = media->pipeline, *target_entity;
>> +	struct v4l2_query_ext_ctrl query_ext_ctrl = *arg;
>> +	int ret = -EINVAL, num_ctrls = 0;
>> +	struct media_entity_to_cid *ctrls_found;
>> +
>> +	/*
>> +	 * If id is or'ed with V4L2_CTRL_FLAG_NEXT_CTRL then the control to
>> +	 * be found is the one with the next lowest id among all entities
>> +	 * in the pipeline.
>> +	 */
>> +	if (query_ext_ctrl.id & V4L2_CTRL_FLAG_NEXT_CTRL) {
>> +		ctrls_found = malloc(sizeof(*ctrls_found));
>> +
>> +		while (entity) {
>> +			query_ext_ctrl = *arg;
>> +
>> +			ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERY_EXT_CTRL,
>> +					&query_ext_ctrl.id);
>> +			if (!ret) {
>> +				ctrls_found = realloc(ctrls_found,
>> +					sizeof(*ctrls_found) * (num_ctrls + 1));
>> +				ctrls_found[num_ctrls].query_ext_ctrl =
>> +								query_ext_ctrl;
>> +				ctrls_found[num_ctrls].entity = entity;
>> +				++num_ctrls;
>> +			}
>> +
>> +			entity = entity->next;
>> +		}
>> +
>> +		if (num_ctrls == 0) {
>> +			ret = -EINVAL;
>> +			entity = NULL;
>> +			goto done;
>> +		}
>> +
>> +		qsort(ctrls_found, num_ctrls, sizeof(*ctrls_found), sort_ctrls);
>> +
>> +		query_ext_ctrl = ctrls_found[0].query_ext_ctrl;
>> +		target_entity = ctrls_found[0].entity;
>> +
>> +		free(ctrls_found);
>> +	}
>> +
>> +	entity = v4l2_subdev_get_pipeline_entity_by_cid(media, query_ext_ctrl.id);
>> +	if (entity)
>> +		target_entity = entity;
>> +
>> +	ret = SYS_IOCTL(target_entity->sd->fd, VIDIOC_QUERYCTRL,
>> +				&query_ext_ctrl);
>> +
>> +done:
>> +	media_dbg(media,
>> +		  "VIDIOC_QUERY_EXT_CTRL [id: 0x%8.8x, name: %s, entity: %s] (%d)\n",
>> +		  ret ? arg->id : query_ext_ctrl.id,
>> +		  ret ? NULL : query_ext_ctrl.name,
>> +		  target_entity ? target_entity->info.name : NULL, ret);
>> +
>> +	*arg = query_ext_ctrl;
>> +
>> +	return ret;
>> +}
>> +
>> +int media_ioctl_querymenu(struct media_device *media,
>> +			  struct v4l2_querymenu *arg)
>> +{
>> +	struct media_entity *entity = media->pipeline;
>> +	struct v4l2_querymenu querymenu = *arg;
>> +	int ret = -EINVAL;
>> +
>> +	entity = v4l2_subdev_get_pipeline_entity_by_cid(media, querymenu.id);
>> +	if (entity) {
>> +		ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERYMENU, &querymenu);
>> +		goto exit;
>> +	}
>> +
>> +	entity = media->pipeline;
>> +
>> +	while (entity) {
>> +		ret = SYS_IOCTL(entity->sd->fd, VIDIOC_QUERYMENU, &querymenu);
>> +		if (!ret)
>> +			break;
>> +
>> +		entity = entity->next;
>> +	}
>> +
>> +exit:
>> +	*arg = querymenu;
>> +
>> +	media_dbg(media, "VIDIOC_QUERYMENU [id: 0x%8.8x, name: %s, entity: %s] (%d)\n",
>> +		  querymenu.id, ret ? NULL : querymenu.name,
>> +		  entity ? entity->info.name : NULL, ret);
>> +
>> +	return ret;
>> +}
>> diff --git a/utils/media-ctl/libv4l2media_ioctl.h b/utils/media-ctl/libv4l2media_ioctl.h
>> new file mode 100644
>> index 0000000..5501895
>> --- /dev/null
>> +++ b/utils/media-ctl/libv4l2media_ioctl.h
>> @@ -0,0 +1,48 @@
>> +/*
>> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
>> + *              http://www.samsung.com
>> + *
>> + * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU Lesser General Public License as published by
>> + * the Free Software Foundation; either version 2.1 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * Lesser General Public License for more details.
>> + */
>> +
>> +#ifndef __LIBV4L2MEDIA_IOCTL_H
>> +#define __LIBV4L2MEDIA_IOCTL_H
>> +
>> +#include <linux/videodev2.h>
>> +
>> +struct media_device;
>> +
>> +struct media_entity_to_cid {
>> +	struct media_entity *entity;
>> +	union {
>> +		struct v4l2_queryctrl queryctrl;
>> +		struct v4l2_query_ext_ctrl query_ext_ctrl;
>> +	};
>> +};
>> +
>> +int media_ioctl_ctrl(struct media_device *media, int request,
>> +			struct v4l2_control *arg);
>> +
>> +int media_ioctl_ext_ctrl(struct media_device *media, int request,
>> +			struct v4l2_ext_controls *arg);
>> +
>> +int media_ioctl_queryctrl(struct media_device *media,
>> +			struct v4l2_queryctrl *arg);
>> +
>> +int media_ioctl_query_ext_ctrl(struct media_device *media,
>> +			struct v4l2_query_ext_ctrl *arg);
>> +
>> +int media_ioctl_querymenu(struct media_device *media,
>> +			struct v4l2_querymenu *arg);
>> +
>> +#endif /* __LIBV4L2MEDIA_IOCTL_H */
>>
>
>


-- 
Best regards,
Jacek Anaszewski