media: uvcvideo: Factor out clamping from uvc_ctrl_set

Move the logic to a separated function. Do not expect any change.
This is a preparation for supporting compound controls.

Reviewed-by: Yunke Cao <yunkec@google.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Yunke Cao <yunkec@google.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://lore.kernel.org/r/20250203-uvc-roi-v17-9-5900a9fed613@chromium.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index a0156b79ab488681ae7829a1425a3ed16c43c047..b6fd06bd1006147fd4895df251c3d7c5fe7b8cc3 100644 (file)
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2053,30 +2053,17 @@ int uvc_ctrl_get(struct uvc_video_chain *chain, u32 which,
        return -EINVAL;
 }
 
-int uvc_ctrl_set(struct uvc_fh *handle,
-       struct v4l2_ext_control *xctrl)
+static int uvc_ctrl_clamp(struct uvc_video_chain *chain,
+                         struct uvc_control *ctrl,
+                         struct uvc_control_mapping *mapping,
+                         s32 *value_in_out)
 {
-       struct uvc_video_chain *chain = handle->chain;
-       struct uvc_control *ctrl;
-       struct uvc_control_mapping *mapping;
-       s32 value;
+       s32 value = *value_in_out;
        u32 step;
        s32 min;
        s32 max;
        int ret;
 
-       lockdep_assert_held(&chain->ctrl_mutex);
-
-       if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
-               return -EACCES;
-
-       ctrl = uvc_find_control(chain, xctrl->id, &mapping);
-       if (ctrl == NULL)
-               return -EINVAL;
-       if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
-               return -EACCES;
-
-       /* Clamp out of range values. */
        switch (mapping->v4l2_type) {
        case V4L2_CTRL_TYPE_INTEGER:
                if (!ctrl->cached) {
@@ -2094,14 +2081,13 @@ int uvc_ctrl_set(struct uvc_fh *handle,
                if (step == 0)
                        step = 1;
 
-               xctrl->value = min + DIV_ROUND_CLOSEST((u32)(xctrl->value - min),
-                                                       step) * step;
+               value = min + DIV_ROUND_CLOSEST((u32)(value - min), step) * step;
                if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
-                       xctrl->value = clamp(xctrl->value, min, max);
+                       value = clamp(value, min, max);
                else
-                       xctrl->value = clamp_t(u32, xctrl->value, min, max);
-               value = xctrl->value;
-               break;
+                       value = clamp_t(u32, value, min, max);
+               *value_in_out = value;
+               return 0;
 
        case V4L2_CTRL_TYPE_BITMASK:
                if (!ctrl->cached) {
@@ -2110,21 +2096,20 @@ int uvc_ctrl_set(struct uvc_fh *handle,
                                return ret;
                }
 
-               xctrl->value &= uvc_get_ctrl_bitmap(ctrl, mapping);
-               value = xctrl->value;
-               break;
+               value &= uvc_get_ctrl_bitmap(ctrl, mapping);
+               *value_in_out = value;
+               return 0;
 
        case V4L2_CTRL_TYPE_BOOLEAN:
-               xctrl->value = clamp(xctrl->value, 0, 1);
-               value = xctrl->value;
-               break;
+               *value_in_out = clamp(value, 0, 1);
+               return 0;
 
        case V4L2_CTRL_TYPE_MENU:
-               if (xctrl->value < (ffs(mapping->menu_mask) - 1) ||
-                   xctrl->value > (fls(mapping->menu_mask) - 1))
+               if (value < (ffs(mapping->menu_mask) - 1) ||
+                   value > (fls(mapping->menu_mask) - 1))
                        return -ERANGE;
 
-               if (!test_bit(xctrl->value, &mapping->menu_mask))
+               if (!test_bit(value, &mapping->menu_mask))
                        return -EINVAL;
 
                /*
@@ -2132,8 +2117,7 @@ int uvc_ctrl_set(struct uvc_fh *handle,
                 * UVC controls that support it.
                 */
                if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK) {
-                       int val = uvc_mapping_get_menu_value(mapping,
-                                                            xctrl->value);
+                       int val = uvc_mapping_get_menu_value(mapping, value);
                        if (!ctrl->cached) {
                                ret = uvc_ctrl_populate_cache(chain, ctrl);
                                if (ret < 0)
@@ -2143,14 +2127,36 @@ int uvc_ctrl_set(struct uvc_fh *handle,
                        if (!(uvc_get_ctrl_bitmap(ctrl, mapping) & val))
                                return -EINVAL;
                }
-               value = xctrl->value;
-               break;
+               return 0;
 
        default:
-               value = xctrl->value;
-               break;
+               return 0;
        }
 
+       return 0;
+}
+
+int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl)
+{
+       struct uvc_video_chain *chain = handle->chain;
+       struct uvc_control_mapping *mapping;
+       struct uvc_control *ctrl;
+       int ret;
+
+       lockdep_assert_held(&chain->ctrl_mutex);
+
+       if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
+               return -EACCES;
+
+       ctrl = uvc_find_control(chain, xctrl->id, &mapping);
+       if (!ctrl)
+               return -EINVAL;
+       if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
+               return -EACCES;
+
+       ret = uvc_ctrl_clamp(chain, ctrl, mapping, &xctrl->value);
+       if (ret)
+               return ret;
        /*
         * If the mapping doesn't span the whole UVC control, the current value
         * needs to be loaded from the device to perform the read-modify-write
@@ -2169,7 +2175,7 @@ int uvc_ctrl_set(struct uvc_fh *handle,
                       ctrl->info.size);
        }
 
-       uvc_mapping_set_s32(mapping, value,
+       uvc_mapping_set_s32(mapping, xctrl->value,
                            uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 
        ctrl->dirty = 1;