[RFC, libv4l]: Make libv4l2 usable on devices with complex pipeline

[Pavel Machek <pavel@ucw.cz>]

[-- Attachment #1: Type: text/plain, Size: 8101 bytes --]

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@ucw.cz>

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);
 }
 


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]