Nouveau - Oct 2022 - [PATCH v5 12/22] drm/connector: Add a function to lookup a TV mode by its name

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 at 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)
+{
+	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);
 

-- 
b4 0.11.0-dev-7da52

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 at 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);
>  
>