Re: [PATCH v3 1/7] media: uvcvideo: Add missing value for power_line_frequency

From: Laurent Pinchart
Date: Tue Jun 07 2022 - 20:17:10 EST


Hi Ricardo,

Thank you for the patch.

On Tue, Jun 07, 2022 at 03:43:58PM +0200, Ricardo Ribalda wrote:
> UVC 1.5 class defines 4 values for this control on:
> 4.2.2.3.6 Power Line Frequency Control
>
> Add the missing value when the uvc version is 1.5.
>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 67 ++++++++++++++++++++++++++------
> 1 file changed, 55 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 0e78233fc8a0..f9d4ac81e62f 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -362,12 +362,19 @@ static const u32 uvc_control_classes[] = {
> V4L2_CID_USER_CLASS,
> };
>
> -static const struct uvc_menu_info power_line_frequency_controls[] = {
> +static const struct uvc_menu_info power_line_frequency_controls_uvc11[] = {
> { 0, "Disabled" },
> { 1, "50 Hz" },
> { 2, "60 Hz" },
> };

Let's drop this, and ...

>
> +static const struct uvc_menu_info power_line_frequency_controls_uvc15[] = {

... rename this to power_line_frequency_controls, and ...

> + { 0, "Disabled" },
> + { 1, "50 Hz" },
> + { 2, "60 Hz" },
> + { 3, "Auto" },
> +};
> +
> static const struct uvc_menu_info exposure_auto_controls[] = {
> { 2, "Auto Mode" },
> { 1, "Manual Mode" },
> @@ -504,17 +511,6 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
> .v4l2_type = V4L2_CTRL_TYPE_INTEGER,
> .data_type = UVC_CTRL_DATA_TYPE_UNSIGNED,
> },
> - {
> - .id = V4L2_CID_POWER_LINE_FREQUENCY,
> - .entity = UVC_GUID_UVC_PROCESSING,
> - .selector = UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
> - .size = 2,
> - .offset = 0,
> - .v4l2_type = V4L2_CTRL_TYPE_MENU,
> - .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> - .menu_info = power_line_frequency_controls,
> - .menu_count = ARRAY_SIZE(power_line_frequency_controls),
> - },
> {
> .id = V4L2_CID_HUE_AUTO,
> .entity = UVC_GUID_UVC_PROCESSING,
> @@ -730,6 +726,32 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
> },
> };
>
> +static const
> +struct uvc_control_mapping power_line_mapping_uvc11 = {
> + .id = V4L2_CID_POWER_LINE_FREQUENCY,
> + .entity = UVC_GUID_UVC_PROCESSING,
> + .selector = UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
> + .size = 2,
> + .offset = 0,
> + .v4l2_type = V4L2_CTRL_TYPE_MENU,
> + .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> + .menu_info = power_line_frequency_controls_uvc11,
> + .menu_count = ARRAY_SIZE(power_line_frequency_controls_uvc11),

... use

.menu_count = ARRAY_SIZE(power_line_frequency_controls) - 1,

here. It will avoid duplicating the common menu items.

> +};
> +
> +static const
> +struct uvc_control_mapping power_line_mapping_uvc15 = {

This holds on a single line (and same for uvc11).

> + .id = V4L2_CID_POWER_LINE_FREQUENCY,
> + .entity = UVC_GUID_UVC_PROCESSING,
> + .selector = UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
> + .size = 2,
> + .offset = 0,
> + .v4l2_type = V4L2_CTRL_TYPE_MENU,
> + .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> + .menu_info = power_line_frequency_controls_uvc15,
> + .menu_count = ARRAY_SIZE(power_line_frequency_controls_uvc15),
> +};

How about turning those two into arrays (named uvc_ctrl_mappings_uvc11
and uvc_ctrl_mappings_uvc15) ? uvc_ctrl_init_ctrl() would first loop
over uvc_ctrl_mappings, and then over the version-specific arrays. This
would ease support of further version-specific controls.

> +
> /* ------------------------------------------------------------------------
> * Utility functions
> */
> @@ -2376,6 +2398,22 @@ static void uvc_ctrl_prune_entity(struct uvc_device *dev,
> }
> }
>
> +/*
> + * The powerline control has different valid values depending on the
> + * uvc version.
> + */
> +static void uvc_ctrl_init_powerline(struct uvc_video_chain *chain,
> + struct uvc_control *ctrl)
> +{
> + if (chain->dev->uvc_version < 0x0150) {
> + __uvc_ctrl_add_mapping(chain, ctrl,
> + &power_line_mapping_uvc11);
> + return;
> + }
> +
> + __uvc_ctrl_add_mapping(chain, ctrl, &power_line_mapping_uvc15);
> +}
> +
> /*
> * Add control information and hardcoded stock control mappings to the given
> * device.
> @@ -2385,6 +2423,7 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> {
> const struct uvc_control_info *info = uvc_ctrls;
> const struct uvc_control_info *iend = info + ARRAY_SIZE(uvc_ctrls);
> + static const u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;

Please move this first, the driver declares static variables before the
non-static ones.

> const struct uvc_control_mapping *mapping = uvc_ctrl_mappings;
> const struct uvc_control_mapping *mend =
> mapping + ARRAY_SIZE(uvc_ctrl_mappings);
> @@ -2415,6 +2454,10 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> if (!ctrl->initialized)
> return;
>
> + if (uvc_entity_match_guid(ctrl->entity, uvc_processing_guid) &&
> + ctrl->info.selector == UVC_PU_POWER_LINE_FREQUENCY_CONTROL)
> + return uvc_ctrl_init_powerline(chain, ctrl);
> +
> for (; mapping < mend; ++mapping) {
> if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> ctrl->info.selector == mapping->selector)

--
Regards,

Laurent Pinchart