diff options
Diffstat (limited to 'Documentation/video4linux/v4l2-controls.txt')
| -rw-r--r-- | Documentation/video4linux/v4l2-controls.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt index e2492a9d1027..43da22b89728 100644 --- a/Documentation/video4linux/v4l2-controls.txt +++ b/Documentation/video4linux/v4l2-controls.txt @@ -130,8 +130,18 @@ Menu controls are added by calling v4l2_ctrl_new_std_menu: const struct v4l2_ctrl_ops *ops, u32 id, s32 max, s32 skip_mask, s32 def); +Or alternatively for integer menu controls, by calling v4l2_ctrl_new_int_menu: + + struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, + const struct v4l2_ctrl_ops *ops, + u32 id, s32 max, s32 def, const s64 *qmenu_int); + These functions are typically called right after the v4l2_ctrl_handler_init: + static const s64 exp_bias_qmenu[] = { + -2, -1, 0, 1, 2 + }; + v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls); v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops, V4L2_CID_BRIGHTNESS, 0, 255, 1, 128); @@ -141,6 +151,11 @@ These functions are typically called right after the v4l2_ctrl_handler_init: V4L2_CID_POWER_LINE_FREQUENCY, V4L2_CID_POWER_LINE_FREQUENCY_60HZ, 0, V4L2_CID_POWER_LINE_FREQUENCY_DISABLED); + v4l2_ctrl_new_int_menu(&foo->ctrl_handler, &foo_ctrl_ops, + V4L2_CID_EXPOSURE_BIAS, + ARRAY_SIZE(exp_bias_qmenu) - 1, + ARRAY_SIZE(exp_bias_qmenu) / 2 - 1, + exp_bias_qmenu); ... if (foo->ctrl_handler.error) { int err = foo->ctrl_handler.error; @@ -164,6 +179,12 @@ controls. There is no min argument since that is always 0 for menu controls, and instead of a step there is a skip_mask argument: if bit X is 1, then menu item X is skipped. +The v4l2_ctrl_new_int_menu function creates a new standard integer menu +control with driver-specific items in the menu. It differs from +v4l2_ctrl_new_std_menu in that it doesn't have the mask argument and takes +as the last argument an array of signed 64-bit integers that form an exact +menu item list. + Note that if something fails, the function will return NULL or an error and set ctrl_handler->error to the error code. If ctrl_handler->error was already set, then it will just return and do nothing. This is also true for |