Hi Pavel,
I really don't want to add functions for this to libv4l2. That's just a
quick hack. The real solution is to parse this from a config file. But
that is a lot more work and it is something that needs to be designed
properly.
And that requires someone to put in the time and effort...
Regards,
Hans
On 03/16/2018 09:55 PM, Pavel Machek wrote:
> Hi!
>
> What about something like this?
>
> Pass map of controls and expects fds to libv4l2...
>
> +static struct v4l2_controls_map map = {
> + .num_fds = 2,
> + .num_controls = 3,
> + .map = { [0] = { .control = 0x00980913, .fd = 1 },
> + [1] = { .control = V4L2_CID_EXPOSURE_ABSOLUTE, .fd = 1 },
> + [2] = { .control = V4L2_CID_FOCUS_ABSOLUTE, .fd = 2 },
> +
> + },
> +};
> +
> +static void open_chk(char *name, int fd)
> +{
> + int f = open(name, O_RDWR);
> +
> + if (fd != f) {
> + printf("Unexpected error %m opening %s\n", name);
> + exit(1);
> + }
> +}
> +
> +static void cam_open_n900(struct dev_info *dev)
> +{
> + struct v4l2_format *fmt = &dev->fmt;
> + int fd;
> +
> + map.main_fd = open("/dev/video_ccdc", O_RDWR);
> +
> + open_chk("/dev/video_sensor", map.main_fd+1);
> + open_chk("/dev/video_focus", map.main_fd+2);
> + // open_chk("/dev/video_flash", map.main_fd+3);
> +
> + v4l2_open_pipeline(&map, 0);
> + dev->fd = map.main_fd;
> +
>
> ...so you can use it on complex devices. Tested on my N900.
>
> I guess later helper would be added that would parse some kind of
> descritption file and do open_pipeline(). But.. lets solve that
> next. In the first place, it would be nice to have libv4l2 usable on
> complex devices.
>
> Best regards,
> Pavel
> Signed-off-by: Pavel Machek <pavel@xxxxxx>
>
> diff --git a/lib/include/libv4l2.h b/lib/include/libv4l2.h
> index ea1870d..6220dfd 100644
> --- a/lib/include/libv4l2.h
> +++ b/lib/include/libv4l2.h
> @@ -109,6 +109,23 @@ LIBV4L_PUBLIC int v4l2_get_control(int fd, int cid);
> (note the fd is left open in this case). */
> LIBV4L_PUBLIC int v4l2_fd_open(int fd, int v4l2_flags);
>
> +struct v4l2_control_map {
> + unsigned long control;
> + int fd;
> +};
> +
> +struct v4l2_controls_map {
> + int main_fd;
> + int num_fds;
> + int num_controls;
> + struct v4l2_control_map map[];
> +};
> +
> +LIBV4L_PUBLIC int v4l2_open_pipeline(struct v4l2_controls_map *map, int v4l2_flags);
> +
> +LIBV4L_PUBLIC int v4l2_get_fd_for_control(int fd, unsigned long control);
> +
> +
> #ifdef __cplusplus
> }
> #endif /* __cplusplus */
> diff --git a/lib/libv4l2/libv4l2-priv.h b/lib/libv4l2/libv4l2-priv.h
> index 1924c91..ebe5dad 100644
> --- a/lib/libv4l2/libv4l2-priv.h
> +++ b/lib/libv4l2/libv4l2-priv.h
> @@ -104,6 +104,7 @@ struct v4l2_dev_info {
> void *plugin_library;
> void *dev_ops_priv;
> const struct libv4l_dev_ops *dev_ops;
> + struct v4l2_controls_map *map;
> };
>
> /* From v4l2-plugin.c */
> diff --git a/lib/libv4l2/libv4l2.c b/lib/libv4l2/libv4l2.c
> index 2db25d1..b3ae70b 100644
> --- a/lib/libv4l2/libv4l2.c
> +++ b/lib/libv4l2/libv4l2.c
> @@ -787,6 +787,8 @@ no_capture:
> if (index >= devices_used)
> devices_used = index + 1;
>
> + devices[index].map = NULL;
> +
> /* Note we always tell v4lconvert to optimize src fmt selection for
> our default fps, the only exception is the app explicitly selecting
> a frame rate using the S_PARM ioctl after a S_FMT */
> @@ -1056,12 +1058,39 @@ static int v4l2_s_fmt(int index, struct v4l2_format *dest_fmt)
> return 0;
> }
>
> +int v4l2_get_fd_for_control(int fd, unsigned long control)
> +{
> + int index = v4l2_get_index(fd);
> + struct v4l2_controls_map *map = devices[index].map;
> + int lo = 0;
> + int hi = map->num_controls;
> +
> + while (lo < hi) {
> + int i = (lo + hi) / 2;
> + if (map->map[i].control == control) {
> + return map->map[i].fd + fd;
> + }
> + if (map->map[i].control > control) {
> + hi = i;
> + continue;
> + }
> + if (map->map[i].control < control) {
> + lo = i+1;
> + continue;
> + }
> + printf("Bad: impossible condition in binary search\n");
> + exit(1);
> + }
> + return fd;
> +}
> +
> int v4l2_ioctl(int fd, unsigned long int request, ...)
> {
> void *arg;
> va_list ap;
> int result, index, saved_err;
> - int is_capture_request = 0, stream_needs_locking = 0;
> + int is_capture_request = 0, stream_needs_locking = 0,
> + is_subdev_request = 0;
>
> va_start(ap, request);
> arg = va_arg(ap, void *);
> @@ -1076,18 +1105,20 @@ int v4l2_ioctl(int fd, unsigned long int request, ...)
> ioctl, causing it to get sign extended, depending upon this behavior */
> request = (unsigned int)request;
>
> + /* FIXME */
> if (devices[index].convert == NULL)
> goto no_capture_request;
>
> /* Is this a capture request and do we need to take the stream lock? */
> switch (request) {
> - case VIDIOC_QUERYCAP:
> case VIDIOC_QUERYCTRL:
> case VIDIOC_G_CTRL:
> case VIDIOC_S_CTRL:
> case VIDIOC_G_EXT_CTRLS:
> - case VIDIOC_TRY_EXT_CTRLS:
> case VIDIOC_S_EXT_CTRLS:
> + is_subdev_request = 1;
> + case VIDIOC_QUERYCAP:
> + case VIDIOC_TRY_EXT_CTRLS:
> case VIDIOC_ENUM_FRAMESIZES:
> case VIDIOC_ENUM_FRAMEINTERVALS:
> is_capture_request = 1;
> @@ -1151,10 +1182,15 @@ int v4l2_ioctl(int fd, unsigned long int request, ...)
> }
>
> if (!is_capture_request) {
> + int sub_fd;
> no_capture_request:
> + sub_fd = fd;
> + if (is_subdev_request) {
> + sub_fd = v4l2_get_fd_for_control(index, ((struct v4l2_queryctrl *) arg)->id);
> + }
> result = devices[index].dev_ops->ioctl(
> devices[index].dev_ops_priv,
> - fd, request, arg);
> + sub_fd, request, arg);
> saved_err = errno;
> v4l2_log_ioctl(request, arg, result);
> errno = saved_err;
> @@ -1782,3 +1818,28 @@ int v4l2_get_control(int fd, int cid)
> (qctrl.maximum - qctrl.minimum) / 2) /
> (qctrl.maximum - qctrl.minimum);
> }
> +
> +
> +int v4l2_open_pipeline(struct v4l2_controls_map *map, int v4l2_flags)
> +{
> + int index;
> + int i;
> +
> + for (i=0; i<map->num_controls; i++) {
> + printf("%lx %d\n", map->map[i].control, map->map[i].fd);
> + if (map->map[i].fd <= 0) {
> + printf("Bad fd in map\n");
> + return -1;
> + }
> + if (i>=1 && map->map[i].control <= map->map[i-1].control) {
> + printf("Not sorted\n");
> + return -1;
> + }
> + }
> +
> + v4l2_fd_open(map->main_fd, v4l2_flags);
> + index = v4l2_get_index(map->main_fd);
> + devices[index].map = map;
> + return 0;
> +}
> +
> diff --git a/lib/libv4lconvert/control/libv4lcontrol.c b/lib/libv4lconvert/control/libv4lcontrol.c
> index 1e784ed..1963e7e 100644
> --- a/lib/libv4lconvert/control/libv4lcontrol.c
> +++ b/lib/libv4lconvert/control/libv4lcontrol.c
> @@ -865,6 +865,7 @@ int v4lcontrol_vidioc_queryctrl(struct v4lcontrol_data *data, void *arg)
> struct v4l2_queryctrl *ctrl = arg;
> int retval;
> uint32_t orig_id = ctrl->id;
> + int fd;
>
> /* if we have an exact match return it */
> for (i = 0; i < V4LCONTROL_COUNT; i++)
> @@ -874,8 +875,9 @@ int v4lcontrol_vidioc_queryctrl(struct v4lcontrol_data *data, void *arg)
> return 0;
> }
>
> + fd = v4l2_get_fd_for_control(data->fd, ctrl->id);
> /* find out what the kernel driver would respond. */
> - retval = data->dev_ops->ioctl(data->dev_ops_priv, data->fd,
> + retval = data->dev_ops->ioctl(data->dev_ops_priv, fd,
> VIDIOC_QUERYCTRL, arg);
>
> if ((data->priv_flags & V4LCONTROL_SUPPORTS_NEXT_CTRL) &&
> @@ -905,6 +907,7 @@ int v4lcontrol_vidioc_g_ctrl(struct v4lcontrol_data *data, void *arg)
> {
> int i;
> struct v4l2_control *ctrl = arg;
> + int fd;
>
> for (i = 0; i < V4LCONTROL_COUNT; i++)
> if ((data->controls & (1 << i)) &&
> @@ -913,7 +916,8 @@ int v4lcontrol_vidioc_g_ctrl(struct v4lcontrol_data *data, void *arg)
> return 0;
> }
>
> - return data->dev_ops->ioctl(data->dev_ops_priv, data->fd,
> + fd = v4l2_get_fd_for_control(data->fd, ctrl->id);
> + return data->dev_ops->ioctl(data->dev_ops_priv, fd,
> VIDIOC_G_CTRL, arg);
> }
>
> @@ -996,6 +1000,7 @@ int v4lcontrol_vidioc_s_ctrl(struct v4lcontrol_data *data, void *arg)
> {
> int i;
> struct v4l2_control *ctrl = arg;
> + int fd;
>
> for (i = 0; i < V4LCONTROL_COUNT; i++)
> if ((data->controls & (1 << i)) &&
> @@ -1010,7 +1015,8 @@ int v4lcontrol_vidioc_s_ctrl(struct v4lcontrol_data *data, void *arg)
> return 0;
> }
>
> - return data->dev_ops->ioctl(data->dev_ops_priv, data->fd,
> + fd = v4l2_get_fd_for_control(data->fd, ctrl->id);
> + return data->dev_ops->ioctl(data->dev_ops_priv, fd,
> VIDIOC_S_CTRL, arg);
> }
>
>
>
