[PATCH v5 2/2] V4L: uvcvideo: Add support for pan/tilt speed controls

Vincent Palatin
2014-10-06T21:06:03Z

Map V4L2_CID_TILT_SPEED and V4L2_CID_PAN_SPEED to the standard UVC
CT_PANTILT_RELATIVE_CONTROL terminal control request.

Tested by plugging a Logitech ConferenceCam C3000e USB camera
and controlling pan/tilt from the userspace using the VIDIOC_S_CTRL ioctl.
Verified that it can pan and tilt at the same time in both directions.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Pawel Osciak <posciak@chromium.org>
---
Changes from v1/v2:
- rebased
Changes from v3:
- removed gerrit-id
Chnages from v4:
- switched "offset" to unsigned int

drivers/media/usb/uvc/uvc_ctrl.c | 58 +++++++++++++++++++++++++++++++++++++---
1 file changed, 55 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 0eb82106..d2d1755 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -309,9 +309,8 @@ static struct uvc_control_info uvc_ctrls[] = {
.selector = UVC_CT_PANTILT_RELATIVE_CONTROL,
.index = 12,
.size = 4,
- .flags = UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
- | UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
- | UVC_CTRL_FLAG_GET_DEF
+ .flags = UVC_CTRL_FLAG_SET_CUR
+ | UVC_CTRL_FLAG_GET_RANGE
| UVC_CTRL_FLAG_AUTO_UPDATE,
},
{
@@ -391,6 +390,35 @@ static void uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
data[2] = min((int)abs(value), 0xff);
}

+static __s32 uvc_ctrl_get_rel_speed(struct uvc_control_mapping *mapping,
+ __u8 query, const __u8 *data)
+{
+ unsigned int first = mapping->offset / 8;
+ __s8 rel = (__s8)data[first];
+
+ switch (query) {
+ case UVC_GET_CUR:
+ return (rel == 0) ? 0 : (rel > 0 ? data[first+1]
+ : -data[first+1]);
+ case UVC_GET_MIN:
+ return -data[first+1];
+ case UVC_GET_MAX:
+ case UVC_GET_RES:
+ case UVC_GET_DEF:
+ default:
+ return data[first+1];
+ }
+}
+
+static void uvc_ctrl_set_rel_speed(struct uvc_control_mapping *mapping,
+ __s32 value, __u8 *data)
+{
+ unsigned int first = mapping->offset / 8;
+
+ data[first] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
+ data[first+1] = min_t(int, abs(value), 0xff);
+}
+
static struct uvc_control_mapping uvc_ctrl_mappings[] = {
{
.id = V4L2_CID_BRIGHTNESS,
@@ -677,6 +705,30 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] = {
.data_type = UVC_CTRL_DATA_TYPE_SIGNED,
},
{
+ .id = V4L2_CID_PAN_SPEED,
+ .name = "Pan (Speed)",
+ .entity = UVC_GUID_UVC_CAMERA,
+ .selector = UVC_CT_PANTILT_RELATIVE_CONTROL,
+ .size = 16,
+ .offset = 0,
+ .v4l2_type = V4L2_CTRL_TYPE_INTEGER,
+ .data_type = UVC_CTRL_DATA_TYPE_SIGNED,
+ .get = uvc_ctrl_get_rel_speed,
+ .set = uvc_ctrl_set_rel_speed,
+ },
+ {
+ .id = V4L2_CID_TILT_SPEED,
+ .name = "Tilt (Speed)",
+ .entity = UVC_GUID_UVC_CAMERA,
+ .selector = UVC_CT_PANTILT_RELATIVE_CONTROL,
+ .size = 16,
+ .offset = 16,
+ .v4l2_type = V4L2_CTRL_TYPE_INTEGER,
+ .data_type = UVC_CTRL_DATA_TYPE_SIGNED,
+ .get = uvc_ctrl_get_rel_speed,
+ .set = uvc_ctrl_set_rel_speed,
+ },
+ {
.id = V4L2_CID_PRIVACY,
.name = "Privacy",
.entity = UVC_GUID_UVC_CAMERA,
--
2.1.0.rc2.206.gedb03e5