Re: [PATCH v2 09/33] drm/connector: Add TV standard property

["Noralf Trønnes" <noralf@tronnes.org>]

Den 22.09.2022 16.25, skrev Maxime Ripard:
> The TV mode property has been around for a while now to select and get the
> current TV mode output on an analog TV connector.
> 
> Despite that property name being generic, its content isn't and has been
> driver-specific which makes it hard to build any generic behaviour on top
> of it, both in kernel and user-space.
> 
> Let's create a new enum tv norm property, that can contain any of the
> analog TV standards currently supported by kernel drivers. Each driver can
> then pass in a bitmask of the modes it supports, and the property
> creation function will filter out the modes not supported.
> 
> We'll then be able to phase out the older tv mode property.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 

Please can you add per patch changelogs, it's hard to review when I have
to recall what might have happened with each patch. If you do it drm
style and put in the commit message it should be easy enough to do.

> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 4e4fbc9e0049..e7aa8de08f5b 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -980,6 +980,18 @@ static const struct drm_prop_enum_list drm_dvi_i_subconnector_enum_list[] = {
>  DRM_ENUM_NAME_FN(drm_get_dvi_i_subconnector_name,
>  		 drm_dvi_i_subconnector_enum_list)
>  
> +static const struct drm_prop_enum_list drm_tv_mode_enum_list[] = {
> +	{ DRM_MODE_TV_MODE_NONE, "None" },
> +	{ DRM_MODE_TV_MODE_NTSC, "NTSC" },

I think going back to plain NTSC and PAL is a good choice for the common
variants.

> +	{ DRM_MODE_TV_MODE_NTSC_443, "NTSC-443" },
> +	{ DRM_MODE_TV_MODE_NTSC_J, "NTSC-J" },
> +	{ DRM_MODE_TV_MODE_PAL, "PAL" },
> +	{ DRM_MODE_TV_MODE_PAL_M, "PAL-M" },
> +	{ DRM_MODE_TV_MODE_PAL_N, "PAL-N" },
> +	{ DRM_MODE_TV_MODE_SECAM, "SECAM" },
> +};
> +DRM_ENUM_NAME_FN(drm_get_tv_mode_name, drm_tv_mode_enum_list)
> +
>  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 */
> @@ -1645,6 +1657,10 @@ EXPORT_SYMBOL(drm_mode_create_tv_margin_properties);
>   * responsible for allocating a list of format names and passing them to
>   * this routine.
>   *
> + * NOTE: This functions registers the deprecated "mode" connector
> + * property to select the analog TV mode (ie, NTSC, PAL, etc.). New
> + * drivers must use drm_mode_create_tv_properties() instead.
> + *
>   * Returns:
>   * 0 on success or a negative error code on failure.
>   */
> @@ -1686,7 +1702,6 @@ int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
>  	if (drm_mode_create_tv_margin_properties(dev))
>  		goto nomem;
>  
> -
>  	if (num_modes) {
>  		dev->mode_config.legacy_tv_mode_property =
>  			drm_property_create(dev, DRM_MODE_PROP_ENUM,
> @@ -1735,6 +1750,49 @@ int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
>  }
>  EXPORT_SYMBOL(drm_mode_create_tv_properties_legacy);
>  
> +/**
> + * drm_mode_create_tv_properties - create TV specific connector properties
> + * @dev: DRM device
> + * @supported_tv_modes: Bitmask of TV modes supported (See DRM_MODE_TV_MODE_*)
> +
> + * Called by a driver's TV initialization routine, this function creates
> + * the TV specific connector properties for a given device.  Caller is
> + * responsible for allocating a list of format names and passing them to
> + * this routine.

Copy-paste error, there are no format names in this version.

> + *
> + * Returns:
> + * 0 on success or a negative error code on failure.
> + */
> +int drm_mode_create_tv_properties(struct drm_device *dev,
> +				  unsigned int supported_tv_modes)
> +{
> +	struct drm_prop_enum_list tv_mode_list[DRM_MODE_TV_MODE_MAX];
> +	struct drm_property *tv_mode;
> +	unsigned int i, len = 0;
> +
> +	if (dev->mode_config.tv_mode_property)
> +		return 0;
> +
> +	for (i = 0; i < DRM_MODE_TV_MODE_MAX; i++) {
> +		if (!(supported_tv_modes & BIT(i)))
> +			continue;
> +
> +		tv_mode_list[len].type = i;
> +		tv_mode_list[len].name = drm_get_tv_mode_name(i);
> +		len++;
> +	}
> +
> +	tv_mode = drm_property_create_enum(dev, 0, "TV mode",
> +					   tv_mode_list, len);
> +	if (!tv_mode)
> +		return -ENOMEM;
> +
> +	dev->mode_config.tv_mode_property = tv_mode;
> +
> +	return drm_mode_create_tv_properties_legacy(dev, 0, NULL);
> +}
> +EXPORT_SYMBOL(drm_mode_create_tv_properties);
> +
>  /**
>   * drm_mode_create_scaling_mode_property - create scaling mode property
>   * @dev: DRM device
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index d566b4a4709c..fffacbfd0a45 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -143,6 +143,71 @@ enum subpixel_order {
>  
>  };
>  
> +/**
> + * enum drm_connector_tv_mode - Analog TV output mode
> + *
> + * This enum is used to indicate the TV output mode used on an analog TV
> + * connector.
> + *
> + * WARNING: The values of this enum is uABI since they're exposed in the
> + * "TV mode" connector property.
> + */
> +enum drm_connector_tv_mode {
> +	/**
> +	 * @DRM_MODE_TV_MODE_NONE: Placeholder to not default on one
> +	 * variant or the other when nothing is set.
> +	 */
> +	DRM_MODE_TV_MODE_NONE = 0,

How is this supposed to be used?

Noralf.

> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_NTSC: CCIR System M (aka 525-lines)
> +	 * together with the NTSC Color Encoding.
> +	 */
> +	DRM_MODE_TV_MODE_NTSC,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_NTSC_443: Variant of
> +	 * @DRM_MODE_TV_MODE_NTSC. Uses a color subcarrier frequency
> +	 * of 4.43 MHz.
> +	 */
> +	DRM_MODE_TV_MODE_NTSC_443,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_NTSC_J: Variant of @DRM_MODE_TV_MODE_NTSC
> +	 * used in Japan. Uses a black level equals to the blanking
> +	 * level.
> +	 */
> +	DRM_MODE_TV_MODE_NTSC_J,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_PAL: CCIR System B together with the PAL
> +	 * color system.
> +	 */
> +	DRM_MODE_TV_MODE_PAL,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_PAL_M: CCIR System M (aka 525-lines)
> +	 * together with the PAL color encoding
> +	 */
> +	DRM_MODE_TV_MODE_PAL_M,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_PAL_N: CCIR System N together with the PAL
> +	 * color encoding. It uses 625 lines, but has a color subcarrier
> +	 * frequency of 3.58MHz, the SECAM color space, and narrower
> +	 * channels compared to most of the other PAL variants.
> +	 */
> +	DRM_MODE_TV_MODE_PAL_N,
> +
> +	/**
> +	 * @DRM_MODE_TV_MODE_SECAM: CCIR System B together with the
> +	 * SECAM color system.
> +	 */
> +	DRM_MODE_TV_MODE_SECAM,
> +
> +	DRM_MODE_TV_MODE_MAX,
> +};
> +
>  /**
>   * struct drm_scrambling: sink's scrambling support.
>   */
> @@ -696,6 +761,7 @@ struct drm_connector_tv_margins {
>   * @subconnector: detected subconnector
>   * @margins: TV margins
>   * @legacy_mode: Legacy TV mode, driver specific value
> + * @mode: TV mode
>   * @brightness: brightness in percent
>   * @contrast: contrast in percent
>   * @flicker_reduction: flicker reduction in percent
> @@ -708,6 +774,7 @@ struct drm_tv_connector_state {
>  	enum drm_mode_subconnector subconnector;
>  	struct drm_connector_tv_margins margins;
>  	unsigned int legacy_mode;
> +	unsigned int mode;
>  	unsigned int brightness;
>  	unsigned int contrast;
>  	unsigned int flicker_reduction;
> @@ -1789,6 +1856,7 @@ const char *drm_get_subpixel_order_name(enum subpixel_order order);
>  const char *drm_get_dpms_name(int val);
>  const char *drm_get_dvi_i_subconnector_name(int val);
>  const char *drm_get_dvi_i_select_name(int val);
> +const char *drm_get_tv_mode_name(int val);
>  const char *drm_get_tv_subconnector_name(int val);
>  const char *drm_get_tv_select_name(int val);
>  const char *drm_get_dp_subconnector_name(int val);
> @@ -1802,6 +1870,8 @@ int drm_mode_create_tv_margin_properties(struct drm_device *dev);
>  int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
>  					 unsigned int num_modes,
>  					 const char * const modes[]);
> +int drm_mode_create_tv_properties(struct drm_device *dev,
> +				  unsigned int supported_tv_modes);
>  void drm_connector_attach_tv_margin_properties(struct drm_connector *conn);
>  int drm_mode_create_scaling_mode_property(struct drm_device *dev);
>  int drm_connector_attach_content_type_property(struct drm_connector *dev);
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index 35a827175c24..10a6f7d1df0d 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -718,9 +718,17 @@ struct drm_mode_config {
>  	/**
>  	 * @legacy_tv_mode_property: Optional TV property to select
>  	 * the output TV mode.
> +	 *
> +	 * Superseeded by @tv_mode_property
>  	 */
>  	struct drm_property *legacy_tv_mode_property;
>  
> +	/**
> +	 * @tv_mode_property: Optional TV property to select the TV
> +	 * standard output on the connector.
> +	 */
> +	struct drm_property *tv_mode_property;
> +
>  	/**
>  	 * @tv_left_margin_property: Optional TV property to set the left
>  	 * margin (expressed in pixels).
>