Re: [PATCH v5 12/22] drm/connector: Add a function to lookup a TV mode by its name

Noralf Trønnes
2022-10-17T10:49:35Z

Den 13.10.2022 15.18, skrev Maxime Ripard:
> As part of the command line parsing rework coming in the next patches,
> we'll need to lookup drm_connector_tv_mode values by their name, already
> defined in drm_tv_mode_enum_list.
>
> In order to avoid any code duplication, let's do a function that will
> perform a lookup of a TV mode name and return its value.
>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
> drivers/gpu/drm/drm_connector.c | 24 ++++++++++++++++++++++++
> include/drm/drm_connector.h | 2 ++
> 2 files changed, 26 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 820f4c730b38..30611c616435 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -991,6 +991,30 @@ static const struct drm_prop_enum_list drm_tv_mode_enum_list[] = {
> };
> DRM_ENUM_NAME_FN(drm_get_tv_mode_name, drm_tv_mode_enum_list)
>
> +/**
> + * drm_get_tv_mode_from_name - Translates a TV mode name into its enum value
> + * @name: TV Mode name we want to convert
> + * @len: Length of @name
> + *
> + * Translates @name into an enum drm_connector_tv_mode.
> + *
> + * Returns: the enum value on success, a negative errno otherwise.
> + */
> +int drm_get_tv_mode_from_name(const char *name, size_t len)

Do we really need to pass in length here?
item->name has to always be NUL terminated otherwise things would break
elsewhere, so it shouldn't be necessary AFAICS.

Noralf.

> +{
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(drm_tv_mode_enum_list); i++) {
> + const struct drm_prop_enum_list *item = &drm_tv_mode_enum_list[i];
> +
> + if (strlen(item->name) == len && !strncmp(item->name, name, len))
> + return item->type;
> + }
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL(drm_get_tv_mode_from_name);
> +
> static const struct drm_prop_enum_list drm_tv_select_enum_list[] = {
> { DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
> { DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index a501db7d2222..a33f24a76738 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1864,6 +1864,8 @@ const char *drm_get_dp_subconnector_name(int val);
> const char *drm_get_content_protection_name(int val);
> const char *drm_get_hdcp_content_type_name(int val);
>
> +int drm_get_tv_mode_from_name(const char *name, size_t len);
> +
> int drm_mode_create_dvi_i_properties(struct drm_device *dev);
> void drm_connector_attach_dp_subconnector_property(struct drm_connector *connector);